ALBERT

Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agriculture, Ecosystems & Environment, Volume 283〈/p〉 〈p〉Author(s): 〈/p〉

Description: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Forest Ecology and Management, Volume 449〈/p〉 〈p〉Author(s): Yili Guo, Han Y.H. Chen, Azim U. Mallik, Bin Wang, Dongxing Li, Wusheng Xiang, Xiankun Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Litterfall production is a major contributor to ecosystem net primary productivity and biogeochemical cycles. However, how various abiotic and biotic drivers influence litterfall production in heterogeneous natural forests is still debated. We used structural equation models (SEM) to test the direct and indirect effects of tree species diversity, tree diameter variation, stand basal area, and abiotic drivers (canopy exposure, elevation, slope, convexity, aspect, topographic wetness index and altitude above channel) on annual litterfall production in a heterogeneous tropical karst seasonal rainforest in Southern China. The SEM with tree species diversity, tree diameter variation, stand basal area, and abiotic drivers accounted for 43.4% of the variation in annual litterfall production. Tree species diversity and stand basal area had positive direct effects, while tree diameter variation had a negative direct effect on annual litterfall production. Tree species diversity had no significant effect on tree diameter variation nor stand basal area. Both annual litterfall production and tree species diversity decreased directly with water availability, while canopy exposure positively affected annual litterfall production but not tree species diversity. Our results indicate that the positive relationship between tree species diversity and litterfall production did not result from the effects of species diversity on canopy packing; instead, it appears that increasing soil water availability simultaneously reduce tree species diversity and annual litterfall production in the tropical karst seasonal rainforest.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geoderma, Volume 353〈/p〉 〈p〉Author(s): Jingzhe Wang, Jianli Ding, Danlin Yu, Xuankai Ma, Zipeng Zhang, Xiangyu Ge, Dexiong Teng, Xiaohang Li, Jing Liang, Ivan Lizaga, Xiangyue Chen, Lin Yuan, Yahui Guo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Soil salinization is one of the most important causes for land degradation and desertification and is an important threat to land management, farming activities, water quality, and sustainable development in arid and semi-arid areas. Soil salinization is often characterized with significant spatiotemporal dynamics. The salt-affected soil is predominant in the Ebinur Lake region in the Northwestern China. However, detailed local soil salinity information is ambiguous at the best due to limited monitoring techniques. Nowadays, the availability of Multi-Spectral Instrument (MSI) onboard Sentinel-2, offers unprecedented perspectives for the monitoring and mapping of soil salinity. The use of MSI data is an innovative attempt for salinity detection in arid land. We hypothesize that field observations and MSI data and MSI data-derived spectral indices using the partial least square regression (PLSR) approach will yield fairly accurate regional salinity map. Based on electrical conductivity of 1:5 soil:water extract (EC) of 72 ground-truth measurements (out of 116 sample sites) and various spectral parameters, such as satellite band reflectance, published satellite salinity indices, red-edge indices, newly constructed two-band indices, and three-band indices from MSI data, we built a few inversion models in an attempt to produce the regional salinity maps. Different algorithms including Pearson correlation coefficient method (PCC), variable importance in projection (VIP), Gray relational analysis (GRA), and random forest (RF) were applied for variable selection. The results suggest that both the newly proposed normalized difference index (NDI) [(B12 − B7) / (B12 + B7)] and three-band index (TBI4) [(B12 − B3) / (B3 − B11)] show a better correlation with validation data and could be applied to estimate the soil salinity in the Ebinur Lake region. The established models were validated using the remaining 44 independent ground-based measurements. The RF-PLSR model performed the best across the five models with R〈sup〉2〈/sup〉〈sub〉V〈/sub〉, RMSE〈sub〉V〈/sub〉, and RPD of 0.92, 7.58 dS m〈sup〉−1〈/sup〉, and 2.36, respectively. The result from this model was then used to map the soil salinity over the study area. Our analyses suggest that soil salinization changes quite significantly in different seasons. Specifically, soil salinity in the dry season was higher than in the wet season, mostly in the lake area and nearby shores. We contend that the results from the study will be useful for soil salinization monitoring and land reclamation in arid or semi-arid regions outside the current study area.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Soil Ecology, Volume 144〈/p〉 〈p〉Author(s): Kobayashi Makoto, Semyon V. Bryanin, Kentaro Takagi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Due to spring climate warming, snowpack has been decreasing and the snowmelt timing has simultaneously been advancing in the cool-temperate forests of northern Japan. To investigate the effect of advancing snowmelt at the end of the snow season on soil nitrogen dynamics via overwintering earthworms, we conducted a snow removal field experiment at the end of the snow season using mesocosms with and without earthworms. In this study, the differences in the effect of snow removal on soil nitrogen according to the presence/absence and body size of 〈em〉Eisenia japonica〈/em〉 were also tested in both early spring (April) and late spring (May). The snow removal did not influence the survival rate, body weight, or cast production of 〈em〉E. japonica〈/em〉. In early spring, while the snow removal increased nitrification significantly by 61%, the effect of snow removal was similar irrespective of the earthworm treatments. This indicates that neither the presence of earthworms nor earthworm body size influences the effect of snow reductions at the end of the snow season on the soil nitrogen dynamics in early spring. On the other hand, in late spring, snow removal no longer had a significant effect on soil nitrogen dynamics, while ammonification and nitrification significantly increased by 195% and by 50%, respectively, in the mesocosms with adult earthworms compared to the mesocosms without 〈em〉E. japonica〈/em〉 earthworms. These findings indicate that the effects of snow decrease and the simultaneous advancement of snowmelt timing at the end of the snow season on soil nitrogen appear only just after snowmelt; alternatively, the effect of earthworm body size on soil nitrogen dynamics is predominant in late spring in snowy cool-temperate forests.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agriculture, Ecosystems & Environment, Volume 284〈/p〉 〈p〉Author(s): Sébastien Boinot, Guillaume Fried, Jonathan Storkey, Helen Metcalfe, Karim Barkaoui, Pierre-Éric Lauri, Delphine Mézière〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Alley cropping agroforestry is a land use practice in which arable crops are grown between tree rows. In such agroforestry systems, non-crop herbaceous vegetation develops on the tree rows, resulting in understory vegetation strips (UVS). UVS are perceived both as reservoirs for weeds and opportunities for biodiversity conservation. The purpose of this study was to assess the contribution of UVS to (i) plant spillover and (ii) plant diversity conservation, depending on their functional structure and the farming system. Vegetation surveys were carried out in May 2017 in South-Western France over 16 winter cereal fields (8 alley cropping agroforestry systems and 8 pure crop controls), half under conventional farming and half under organic farming. Using data on plant functional traits related to dispersal strategies and response to agricultural disturbances, we explained the mechanisms involved in plant spillover between habitats. The study revealed that very few species were able to disperse far into crop alleys, except perennial species producing rhizomes and stolons whose spread has been favored by tillage. The presence of UVS in agroforestry fields did not increase weed-crop ratio (i.e. weed coverage / weed and crop coverage) in adjacent crop alleys. On the other hand, UVS harbored richer and more abundant floras (with high proportions of species rarely found in arable habitats) compared to crop alleys and pure crop controls, especially under conventional farming. The functional approach provided insights for weed management in alley cropping agroforestry systems in order to optimize plant diversity conservation without increasing weed-crop ratio. This study showed the relevance of using the functional approach to understand the mechanisms behind plant spillover in cropping systems that integrate semi-natural habitats.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agriculture, Ecosystems & Environment, Volume 284〈/p〉 〈p〉Author(s): Daria Dadam, Gavin M. Siriwardena〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Agri-environment schemes (AESs) have shown mixed success across Europe in terms of meeting environmental targets. Tir Gofal, the first widespread AES in Wales, ran from 1999 to 2013. Here we test the effects of its options on bird population growth rates, using the annual BTO/JNCC/RSPB Breeding Bird Survey (BBS). Using over 400 1-km BBS squares, we applied a log-linear analytical approach that models the average change in expected abundance of individual species between consecutive years, testing the effects of spatio-temporal covariates (here, local quantities of Tir Gofal management and appropriate controls). Management options within the scheme were grouped according to their intended mode of impact on birds and commonalities in the habitat changes that they describe. Overall, 28/97 tests conducted produced positive results, and only four negative ones, a pattern that was also found among priority species alone (14 and two of 58 tests, respectively), involving eight of 17 priority species in Wales. Out of the ten groups of options considered, those concerning woodland, scrub and hedgerows were the most successful, each showing a predominance of positive effects across the bird species tested. Arable and grassland open-field options produced some positive effects, but failed to deliver detectable benefits for priority species, with wet grassland and waders being a particular gap. The non-significant effects found may reflect low analytical power, confounded option and landscape variation or failures of those options to address the key factors limiting species’ populations. Overall, however, this study provides good evidence that Tir Gofal had positive effects on many target bird populations in Wales, showing that the scheme contributed positively to key conservation policy targets, even if significant effects were not detectable on all such species.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Forest Ecology and Management, Volume 449〈/p〉 〈p〉Author(s): Paulo Cañete-Salinas, Francisco Zamudio, Marco Yáñez, Javier Gyenge, Héctor Valdés, Cristian Espinosa, Francisco Jara-Rojas, Jaime Venegas, Luis Retamal, César Acevedo-Opazo〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Water is the main limiting factor for poplar plantations in the Mediterranean zone of central Chile. Overall, water requirements in these plantations may be estimated using climatic and soil moisture data. However, irrigation strategies can be improved if growth and plant water status are considered. The aim of this study was to assess the growth (diameter increments) and leaf-level physiology (xylem water potential (Ψ〈sub〉x〈/sub〉) and stomatal conductance (g〈sub〉s〈/sub〉)) responses of two 〈em〉Populus × canadensis〈/em〉 clones (‘I-214’ and ‘I-488’) to different irrigation frequencies. The study was carried out during three growing seasons in commercial plantations located in the Maule Region, central Chile. Three irrigation frequencies were evaluated: an over-irrigation frequency (21 days) (T1); a standard irrigation frequency used operationally in the area (28 days) (T2) and a deficit irrigation frequency (35 days) (T3), while the watering time was held constant for all treatments. Although both clones belong to the same interspecific cross, they differed in their growth and physiological responses to water deficit. Compared with ‘I-214’, ‘I-488’ was more sensitive to lower irrigation frequencies (higher water restriction), which decreased the diameter increments, the water potential and stomatal conductance. The results suggest that the use of physiological and climatic information may improve water management on commercial poplar plantations.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geoderma, Volume 353〈/p〉 〈p〉Author(s): Roozbeh Moazenzadeh, Babak Mohammadi〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Root zone temperature is one of the most important soil characteristics, controlling many of the physical, chemical and biological processes in the soil. Temperature varies by soil depth, and exerts a profound impact on plant germination and growth. In this study, the accuracy of two artificial intelligence models including support vector regression (SVR) and elman neural network (ENN) and their hybrids with firefly algorithm (SVR-FA and ENN-FA) and krill herd algorithm (SVR-KHA and ENN-KHA) was assessed in estimating soil temperature (Ts) at 5, 10, 20, 30, 50 and 100 cm depths at Maragheh meteorological station in north-western Iran. The results of the models were evaluated under 5 scenarios with various inputs including the main meteorological parameters measured at the station (air temperature, sunshine hours, relative humidity, wind speed and saturation vapour pressure deficit). Daily Ts data recorded from January 1, 2006 to December 30, 2012 and from January 1, 2013 to December 30, 2015 were used for model training and testing, respectively. The results showed that error rates have decreased from 5 to 10 cm soil depth (root mean square error (RMSE) reduced by 2.97, 4.68 and 3.19% for the best scenarios of SVR, SVR-FA and SVR-KHA models, respectively), whereas error rates have been increasing from 10 to 100 cm soil depths (RMSE increased by 62.4, 80.9 and 73.6% for the best scenarios of SVR, SVR-FA and SVR-KHA models, respectively). For the best scenarios of ENN, ENN-FA and ENN-KHA models, RMSE values decreased by 2.1, 1.6 and 3.1% from 5 to 10 cm depth and increased by 61.1, 84.1 and 81.1% from 10 to 100 cm depth, so that all six models reached their best performance at 10 cm soil depth. Examination of the results in terms of under-estimation or over-estimation of Ts indicated that the lowest and highest differences in performance between under- and over-estimation sets were 0.01 °C (SVR-FA at 5 cm depth) and 1.64 °C (SVR at 100 cm depth) for SVR-based models and 0 °C (ENN at 10 cm depth) and 0.56 °C (ENN at 100 cm depth) for ELM-based models, respectively. According to the results from the best scenarios of SVR, SVR-FA and SVR-KHA models in the under-estimation set at 100 cm depth, all the three models have exhibited a poorer performance over the temperature range 15–25 °C (RMSE increased by 56.7, 47 and 61.3% for SVR, SVR-FA and SVR-KHA, respectively) compared to temperature values outside that range. Exactly the same trend was also observed for ELM-based models, where the mentioned increases in RMSE were about 37.7, 59.4 and 55.5% for ELM, ELM-FA and ELM-KHA, respectively. According to the results, bio-inspired metaheuristic optimisation algorithms based on SVR and ENN which use appropriate meteorological parameters as inputs can have a relatively satisfactory performance in estimating Ts under climatic conditions similar to our study area, especially in lower depths, and can be used as an alternative to direct measurement of this important parameter.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Yang Hu, Wei-Chao Chen, Yu-Feng Shen, Bin Zhu, Gao-Xue Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Viral diseases in aquaculture were challenging because there are few preventative measures and/or treatments. Our previous study indicated that imidazole arctigenin derivatives possessed antiviral activities against infectious hematopoietic necrosis virus (IHNV). Based on the structure-activity relationship in that study, a new imidazole arctigenin derivative, 4-(8-(2-ethylimidazole)octyloxy)-arctigenin (EOA), was designed, synthesized and its anti-IHNV activity was evaluated. By comparing inhibitory concentration at half-maximal activity (IC〈sub〉50〈/sub〉), we found that EOA (IC〈sub〉50〈/sub〉 = 0.56 mg/L) possessed a higher antiviral activity than those imidazole arctigenin derivatives in our previous study. Besides, EOA could significantly decrease cytopathic effect (CPE) and viral titer induced by IHNV in epithelioma papulosum cyprinid (EPC) cells. In addition, EOA significantly inhibited apoptosis induced by IHNV in EPC cells. Further data verified that EOA inhibited IHNV replication in rainbow trout, with reducing 32.0% mortality of IHNV-infected fish. The results suggested that EOA was more stable with a prolonged inhibitory half-life in the early stage of virus infection (1–4 days). Consistent with above results, EOA repressed IHNV glycoprotein gene expression in virus sensitive tissues (kidney and spleen) in the early stage of virus infection. Moreover, histopathological evaluation showed that tissues from the spleen and kidney of fish infected with IHNV exhibited pathological changes. But there were no lesions in any of the tissues from the control group and EOA-treaten group. In accordance with the histopathological assay, EOA could elicited anti-inflammation response in non-viral infected rainbow trout by down-regulating the expression of cytokine genes (〈em〉IL-8〈/em〉, 〈em〉IL-12p40〈/em〉, and 〈em〉TNF-α〈/em〉). Altogether, EOA was expected to be a therapeutic agent against IHNV infection in the field of aquaculture.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Junjun He, Haiying Liang, Jiaping Zhu, Xiaochen Fang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Antibacterial peptides (AMPs) constitute an important part of the body's innate immune system and are responsible for a wide range of inhibitory effects against pathogens such as bacteria, fungi, and viruses. In this study, multi-step high performance liquid chromatography (HPLC), combined with Mass Spectrometry (MS), was used to isolate and identify proteins with antibacterial activity from the serum of 〈em〉Pinctada fucata martensii〈/em〉 (〈em〉P.f. Martensii〈/em〉) and obtain a component named 〈em〉P.f. Martensii〈/em〉 antimicrobial peptide-1 (PmAMP-1). 〈em〉PmAMP-1〈/em〉 cDNA was cloned and sequenced by rapid amplification of cDNA ends (RACE) and mRNA expression of was analyzed by quantitative real-time PCR (qRT-PCR). From the results of this study, full-length 〈em〉PmAMP-1 c〈/em〉DNA was shown to be 700 base pairs (bp) long with an open reading frame (ORF) of 294 bp, encoding 97 amino acids with a predicted structure that is mostly α-helices. 〈em〉PmAMP-〈/em〉1 mRNA was constitutively expressed in all tested tissues including the adductor muscle, mantle, hepatopancreas, gill, gonads and hemocytes. The highest level of 〈em〉PmAMP-〈/em〉1 transcription was observed at 8 h and 2 h after bacterial challenge in hemocytes and adductor muscle (p 〈 0.01), respectively. Furthermore, PmAMP-1 caused significant morphological alterations in 〈em〉E. coli,〈/em〉 as shown by transmission electron microscopy (TEM). The results from this study provide a valuable base for further exploration of molluscan innate immunity and immune response.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geoderma, Volume 353〈/p〉 〈p〉Author(s): Lingfei Yu, Yue Chen, Wenjuan Sun, Yao Huang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Globally, excessive grazing is identified as one of the key disturbances leading to grassland degradation and soil carbon (C) loss. Grazing exclusion has been proposed as an effective practice to restore degraded grasslands and to promote C sequestration. However, there is still little knowledge about how soil C changes with grazing exclusion in high-altitude alpine ecosystems with very cold climates. We synthesized data from 63 sites in the literature and 15 sites in a field sampling and investigated the dynamics of soil C stocks following grazing exclusion in alpine grasslands of the Tibetan Plateau. The results showed that the soil C stock increased with grazing exclusion at most sites, with average C sequestration rates of 0.84, 0.58, and 0.49 Mg ha〈sup〉−1〈/sup〉 yr〈sup〉−1〈/sup〉 in the soil layers of 0–10, 10–20, and 20–30 cm, respectively. Based on these results, if 60 million ha of the grasslands on Tibetan Plateau were excluded from grazing livestock by 2020 according to the national plan, then approximately 0.11 Pg C yr〈sup〉−1〈/sup〉 would be sequestered in the soil which equates to about 4.4% of fossil fuel and cement CO〈sub〉2〈/sub〉 emissions in China in 2013. Generally, the rates of soil C increase exhibited a declining pattern with increasing years of grazing exclusion, with a significant decrease occurring after ten years of grazing exclusion. Of the factors examined, the rates of absolute and relative soil C change were both positively related to mean annual precipitation but negatively related to the year of grazing exclusion and initial soil C stock, respectively. The rates of soil C changes increased linearly with those of N change, and no matter how soil C changed (whether it increased or decreased), soil C:N ratios remained stable over the years of grazing exclusion. Our results implied that grazing exclusion is beneficial for soil C sequestration in degraded alpine grassland, especially in humid areas. Moreover, the intrinsic increase in N could keep up with the pace of soil C changes and would sustain soil C sequestration during the recovery process.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geoderma, Volume 353〈/p〉 〈p〉Author(s): Thomas P. D'Avello, William J. Waltman, Sharon W. Waltman, James A. Thompson, Joseph Brennan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉We examine the climatic record of the conterminous United States from 1895 to 2014 as expressed through the PRISM dataset and the jNewhall model. Specifically, the zero line of the Annual Water Balance (AWB) and the respective oscillation zone through its longitudinal extent is examined. The zero line corresponds to the Pedocal/Pedalfer line defined by C.F. Marbut, considered outdated in current pedological circles, but conceptually powerful in denoting regional negative vs. positive AWB. Soil Moisture Regimes are reviewed and a means of expressing Soil Moisture Regime variability is introduced. Results indicate a difference in the width of the AWB oscillation zone from South to North with a demarcation approximating 40 degrees North Latitude. PRISM data is verified from a select set of National Weather Service station data to assess the utility of using readily accessible PRISM data for performing similar work by others. The effect of climate variables on organic carbon (OC) stock and depth of maximum Calcium Carbonate concentration is examined for a suite of soils along a climo-sequence from North Dakota to Central Iowa and found to account for a mild amount of the variability of both variables.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agriculture, Ecosystems & Environment, Volume 284〈/p〉 〈p〉Author(s): Na Guo, A. Allan Degen, Bin Deng, Fuyu Shi, Yanfu Bai, Tao Zhang, Ruijun Long, Zhanhuan Shang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Understanding the changes in vegetation parameters and soil nutrients in the different stages of grasslands degradation and recovery is crucial for assessing and restoring degraded grasslands. Consequently, we determined above-ground vegetation and soil C, N and P concentrations and their stoichiometry in different degradation and recovery stages on the Tibetan Plateau. Four degradation succession stages, GKC: Grass-〈em〉Kobresia〈/em〉 community, KHC: 〈em〉Kobresia humilis〈/em〉 community, KPC: 〈em〉Kobr〈/em〉esia 〈em〉pygmaea〈/em〉 community, and FBC: forbs - black soil beach community, and three recovery succession stages, FG: freely grazed, RG: restricted grazed, and NG: non-grazed, were identified. Above-ground biomass and vegetation coverage decreased with degradation succession and there was a concomitant shift of plant functional groups to more above-ground biomass of forbs and less biomass of grasses and sedges. The highest species diversity emerged in the 〈em〉K. pygmaea〈/em〉 succession stage, mainly due to an influx of Compositae. Significant differences in soil total nitrogen (TN), total phosphorus (TP) and soil organic carbon (SOC) concentrations occurred in the 0–10 and 10–20 cm layers among degradation successions. Vegetation cover, above-ground biomass, soil TN and SOC, as well as C:N and C:P ratios increased in non-grazed grasslands when compared to grazed grasslands. Soil TN, TP and SOC concentrations decreased with increasing soil depths across all degradation and recovery successions. In addition, soil nutrients and their stoichiometry were affected by above-ground biomass. We concluded that grazing exclusion could improve the above-ground vegetation and soil nutrients of degraded alpine grasslands, but that the rate of recovery was related to the degree of degradation.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agriculture, Ecosystems & Environment, Volume 284〈/p〉 〈p〉Author(s): Caroline K. Bosire, Elizaphan James Oburu Rao, Voster Muchenje, Mark Van Wijk, Joseph O. Ogutu, Mesfin M. Mekonnen, Joseph Onam Auma, Ben Lukuyu, James Hammond〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Dairy intensification is a widely used means of achieving food security, improving farmer incomes and enhancing overall economic growth. However, intensification is dependent upon the availability and suitability of natural resources to sustain growth in production. Here, land and water footprints of milk production in three contrasting agro-ecological zones ranging from humid to semi-arid across nine counties of Kenya are quantified. Water and land use footprints across three potential intensification pathways are also outlined and evaluated against the baseline scenario, the currently prevailing practices or the S1 Futures scenario, treated as the benchmark. Intensification pathways focusing on improving livestock breeds, feed provisioning and milk output per cow and distinguished by contrasting management practices perform differentially across the three agro-ecological zones. Total water and land footprints increase for all scenarios relative to the baseline scenario. In particular, all the breed improvement scenarios, have much larger total water footprints than the baseline scenario. Improvement in breed to pure bred cattle across all production systems has the largest total water footprint across all the production systems. Across all the scenarios, the largest reduction in water footprint of milk production (75%) occurs with improvement in breed and feeding practices from two scenarios in the lowlands. Milk production by the cross-bred cattle is most efficient in the lowlands system whereas milk production by the pure breed Ayrshire is most land use efficient in the midlands system. Across the three agroecological zones, improving breeds, feed provisioning and milk production per cow may achieve production intensification but concurrently exacerbates resource limitation. Consequently, the heterogeneity inherent in resource availability across dairy production zones should be considered when developing strategies for increasing dairy production.〈/p〉〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Bin Zhong, Zeyin Jiang, Zhenhuang Chen, Kazue Ishihara, Huilin Mao, Shanghong Wang, Gang Lin, Chengyu Hu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Recently, studies have shown that IκB kinase β (IKKβ), a critical kinase in the nucleus factor kappa-B (NF-κB) pathway, participates in inflammatory responses associated with unfolded protein response (UPR) and plays an important role in ER stress-induced cell death. The unfolded protein response (UPR), which is a regulatory system to restore cellular homeostasis in the endoplasmic reticulum (ER), such as oxidative stress, bacterial infection, and virus invasion. The UPR pathways have been reported to be involved in immune responses in mammals, including the classical NF-κB pathway. However, the molecular mechanism of their crosstalk remains to be elucidated. Previously, we demonstrated that IKKβ also has some conserved functions between fish and human, as grass carp (〈em〉Ctenopharyngodon idella〈/em〉) IKKβ (CiIKKβ) can activate NF-κB pathway. In this study, we found that CiIKKβ level in nucleus was elevated under ER stress and CiIKKβ can interact with grass carp X-box-binding protein 1 (CiXBP1S), a key transcription factor in UPR. Consistently, fluorescent histochemical analysis of grass carp kidney (CIK) cells indicated that CiIKKβ and CiXBP1S colocalized under ER stress. Furthermore, overexpression of CiIKKβ in CIK cells enhanced ER stress tolerance by regulating UPR signaling and resulted in the significant increase of cell viability.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Lu-Yun Ni, Qing Han, Hong-Ping Chen, Xiao-Chun Luo, An-Xing Li, Xue-Ming Dan, Yan-Wei Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Macrophage expressed gene 1 (Mpeg1) is a molecule that can form pores and destroy the cell membrane of invading pathogens. In this study, we identified two Mpeg1 isoforms from the orange-spotted grouper (〈em〉Epinephelus coioides〈/em〉) and named them EcMpeg1a and EcMpeg1b. Predicted proteins of the two EcMpeg1s contained a signal peptide, a conserved membrane attack complex/perforin (MACPF) domain, a transmembrane segment, and an intracellular region. Sequence alignment demonstrated that two EcMpeg1 proteins share a high sequence identity with that of other teleosts. Tissue distribution analysis showed that EcMpeg1s were expressed in all tissues tested in healthy grouper, with the highest expression in the head kidney and spleen. After infection with the ciliate parasite 〈em〉Cryptocaryon irritans〈/em〉, expression of the two EcMpeg1s was significantly upregulated in the spleen and gills. Furthermore, the recombinant EcMpeg1a showed antiparasitic and antibacterial activity against Gram-negative and -positive bacteria, whereas EcMpeg1b had an inhibitory effect only against Gram-positive bacteria. These results indicated that EcMpeg1s play an important role in the host response against invading pathogens.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil and Tillage Research, Volume 194〈/p〉 〈p〉Author(s): Kathryn L Page, Yash P. Dang, Ram C. Dalal, Steven Reeves, Greg Thomas, Weijin Wang, John P. Thompson〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉No-tillage (NT) has been widely adopted to assist in reducing soil erosion, lowering fuel costs, conserving soil water and promoting soil health. However, NT may also have a negative effect on yield depending on season and conditions due to inadequate weed/disease control, nutrient stratification and/or decreased soil temperatures. Therefore, to fully assess its impact, long-term studies are required to monitor changes over time. This study reports on the long-term effect of NT on crop yield and profitability (primarily for wheat, 〈em〉Triticum aestivum〈/em〉 L.) using results from an experiment that has been running for 50 years in a semiarid subtropical region of Australia. In this experiment, the effect of tillage (conventional till (CT) 〈em〉v〈/em〉 no-till (NT)), residue management (stubble burning (SB) 〈em〉v〈/em〉 stubble retention (SR)), and three rates of nitrogen (N) fertiliser (0, 30 and 90 kg N/ha) were measured in a balanced factorial experiment on a Vertisol (Ustic Pellusert). Over the period of the trial (1969–2018), NT with SR resulted in greater average soil water storage in the top 1.5 m of the profile than CT with SB (390 〈em〉v〈/em〉 346 mm). However, nitrate (NO〈sub〉3〈/sub〉-N) accumulation during the fallow period was generally lower with SR and this prevented wheat from fully capitalising of on the increased soil water storage. Consequently, while crop yield was greater under NT 〈em〉v〈/em〉 CT and more so under NT + SR 〈em〉v〈/em〉 CT + SR (particularly in years where in-crop rainfall was 〈˜300 mm), N fertiliser was required to maximise yields. Within the NT treatments, SR also resulted in greater yield in the presence of applied N. Prior to 1992, nematodes prevented wheat crops from capitalising on the increased soil water and reduced yields, however, the introduction of nematode-tolerant cultivars helped maximise crop production. In line with yield effects, gross margins were greater under NT than CT and for SR when N was applied. However, despite greater yield advantages for the 90 N treatments, gross margins were lower at 90 N compared to 30 N. Nitrogen use efficiency with 90 N was approximately half that with 30 N, likely due to greater losses of N at the higher rates of application. To maximise profitability techniques to reduce losses of N are thus desirable. Good disease control, or the use of tolerant/resistant cultivars, is also essential to allow the crop to capitalise on gains in soil water in NT systems.〈/p〉〈/div〉

Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil and Tillage Research, Volume 194〈/p〉 〈p〉Author(s): Qi Chen, Pei-Qin Peng, Jian Long, Xin-Yang Li, Xianqing Ding, Hong-Bo Hou, Bo-Han Liao〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉While the evaluation of cadmium (Cd) phytoavailability in rice (〈em〉Oryza sativa〈/em〉 L.)–soil systems has attracted considerable attention in recent years, the results vary based on the evaluation method used. The objective of this work was to use field capacity-derived soil solution extraction (SSE) to evaluate the Cd phytoavailability in two typical paddy soils (purple paddy soil and red paddy soil) during an entire rice growth season. Compared to three conventional extraction methods diethylenetriaminepentaacetic acid (DTPA) extraction, toxicity characteristic leaching procedure (TCLP), and HCl extraction], field capacity-derived SSE resulted in the strongest correlation between extracted Cd and the Cd contents in different rice tissues (root, gem, leaf, ear, husk, and brown rice). When the data for the two soil types were combined, SSE was the best predictor of total accumulated Cd in rice, with linear correlation coefficients of 0.836, 0.831, 0.919, and 0.909 for the tillering stage, heading stage, filling stage, and mature stage, respectively. In contrast, TCLP was only suitable for predicting total Cd accumulation in the heading and mature stages (linear correlation coefficients of 0.813 and 0.931, respectively), while DTPA was only effective in the heading stage (linear correlation coefficient of 0.8306). These results demonstrate the potential of field capacity-based SSE to predict Cd phytoavailability in soil–rice systems with different soil types.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0167198719300418-ga1.jpg" width="345" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Marine Policy, Volume 107〈/p〉 〈p〉Author(s): Alicia Said, Ratana Chuenpagdee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Since the launch of the Sustainable Development Goals (SDGs) in 2015, several countries, funding organizations, environmental groups and research communities have pledged support and made commitment to help achieve these goals. SDG14: Life Below Water, for instance, has been embraced as the global goal for conservation and sustainable uses of the oceans, seas and marine resources. Among its many targets, SDG14b speaks directly to small-scale fisheries, calling for secured access to resources and markets for this sector. We argue that achieving SDG 14b requires a holistic approach encompassing several SDGs, including livelihoods, economic growth, community sustainability, strong institutions and partnerships. It is also important to align the SDG targets with the Voluntary Guidelines for Securing Sustainable Small-Scale Fisheries (SSF Guidelines), as the mutuality that exists between the scope and nature of the two instruments can help guide the formulation of appropriate governance tools. Yet, the alignment of these two instruments alone does not guarantee sustainability of small-scale fisheries, especially without an official mandate from the governments. The case in point is the European Union where small-scale fisheries are not sufficiently recognized within the Common Fisheries Policy (CFP), despite being the largest sector (75% of the fleet). Through an examination of the CFP in the context of the SSF Guidelines and the SDGs, we discuss options and possibilities for inclusive consideration of small-scale fisheries in the upcoming policy reform, which might then lead to both achieving fisheries sustainability and the SDGs in the EU.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volumes 276–277〈/p〉 〈p〉Author(s): Bin Chen, Jing M. Chen, Dennis D. Baldocchi, Yang Liu, Shaoqiang Wang, Ting Zheng, T.A. Black, Holly Croft〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The impacts of soil water stress on photosynthesis and stomatal conductance have not been uniformly parameterized in terrestrial ecosystem models. This study firstly quantifies diurnal variations in canopy conductance (〈em〉g〈sub〉c,w〈/sub〉〈/em〉) during full-leaf periods from eddy covariance flux data at four flux sites by inverting the Penman-Monteith equation. Then, the Ball-Woodrow-Berry (BWB) slopes were derived and compared under contrasting water stress conditions by linear regression of 〈em〉g〈sub〉c,w〈/sub〉〈/em〉 and gross primary productivity (GPP) derived from EC measurements. Finally, the response of the leaf maximum carboxylation rate to accumulated soil water deficit (ASWD) was explored to develop a better scheme of soil water stress. Our results show: (1) The thresholds of relatively available soil moisture under which soil water stress occurs were 0.575, 0.885, 0.495 and 0.653 for the tropical savanna site (AU-How), the Mediterranean forest site (IT-Col), the Mediterranean grassland site (US-Var) and the boreal forest site (CA-Oas), respectively, derived from the logistic functions of fitting 〈em〉g〈sub〉c,w〈/sub〉〈/em〉 to relatively available soil moisture; (2) similar to previous work, we found that ensemble average 〈em〉g〈sub〉c,w〈/sub〉〈/em〉 of dry periods were lower than those of wet periods at the studied sites, and that BWB slopes did not change significantly during droughts, indicating that BWB slopes may be conserved under prolonged drought; and (3) EC-derived GPP gradually decreased with the increase of ASWD, which can be well captured by a V〈sub〉mr〈/sub〉-ASWD scheme developed in this study. In sum, the V〈sub〉mr〈/sub〉-ASWD scheme would increase the accuracy of GPP simulations of ecosystem models. This study suggests that the change of BWB slopes under prolonged drought is not justified according to the experimental data examined while adjusting V〈sub〉cmax〈/sub〉 with ASWD accounts for the change in leaf physiology due to prolonged drought and is computationally feasible and efficient.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geoderma, Volume 353〈/p〉 〈p〉Author(s): Zengming Chen, Yehong Xu, Daniela F. Cusack, Michael J. Castellano, Weixin Ding〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Nitrogen (N) input rapidly increases available N in natural and managed ecosystems, potentially altering key ecosystem processes like decomposition. The effect of N enrichment on decomposition rates may be affected by the chemical quality of organic matter (OM), and the extent of N increment. Manure decomposition is an important process in agricultural systems, releasing nutrients and contributing to carbon (C) cycling. However, its response to N fertilization is poorly understood. To help address this knowledge gap, we decomposed pig manure (PM) and chicken manure (CM) under two rates of N fertilization (N1, 75 kg N ha〈sup〉−1〈/sup〉; N2, 112.5 kg N ha〈sup〉−1〈/sup〉) in a cropland in northeast China. We used litterbags to determine the dynamics of manure decomposition, while monitoring changes in the molecular composition with solid-state 〈sup〉13〈/sup〉C nuclear magnetic resonance (NMR) spectroscopy. After one-year, the decomposition rate of PM was significantly greater than CM (0.516 vs. 0.483 year〈sup〉−1〈/sup〉). Spectra of 〈sup〉13〈/sup〉C NMR indicated that PM initially contained more 〈em〉O〈/em〉-alkyl C and di-〈em〉O〈/em〉-alkyl C (representing cellulose). In contrast, the contents of alkyl C (representing lipids) and aromatic C (representing lignin) were less in PM than CM, such that PM was overall more easily degradable. There was no N rate effect on CM decomposition. However, the decomposition rate of PM was significantly lower under high N than low N (0.410 vs. 0.622 year〈sup〉−1〈/sup〉), apparently related to suppressed degradation of 〈em〉O〈/em〉-alkyl C and di-〈em〉O〈/em〉-alkyl C. This result was surprising, since N enrichment is generally expected to promote degradation of more labile compounds like cellulose. At the same time, the loss of syringyl monomer of lignin in PM was reduced by high N fertilization. Together, these results suggest that decreased losses of 〈em〉O〈/em〉-alkyl C and di-〈em〉O〈/em〉-alkyl C may have resulted from physical association of cellulose with more resistant lignin compounds. Net N mineralization was observed from manure decomposition and was greater for CM than PM, and high N fertilization suppressed N release from PM. Overall, our findings suggest that high rate of N fertilization may slow the decomposition of otherwise labile manure, potentially promoting greater C retention in soils.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volumes 276–277〈/p〉 〈p〉Author(s): Apurupa Gorthi, Jeffrey J. Volenec, Lisa R. Welp〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Diminishing water resources and an expected increase in frequency of extreme water stress events necessitate tools to diagnose and improve the drivers of variability in agronomic water use efficiency. The objective of this study was to determine if leaf-scale water use efficiency (measured as intrinsic water use efficiency and transpiration efficiency) is expressed at the field scale as yield or agronomic water use efficiency variability. We measured grain yield, total aboveground biomass, and carbon isotope discrimination and estimated evapotranspiration using a mass balance approach for field-grown 〈em〉Glycine max〈/em〉 (soybean) over five years. We found that the high agronomic water use efficiency in years characterized by high vapor pressure deficit was caused by a large reduction in evapotranspiration and a relatively smaller reduction in yield. This has implications for developing drought tolerance in soybeans without compromising yield. We observed a positive relationship between transpiration efficiency and agronomic water use efficiency, with the leaf scale explaining 68% of the variability at the field scale. Through this analysis, we infer that increasing transpiration efficiency at the leaf scale will likely improve agronomic water use efficiency at the field scale in rain-fed soybean systems.〈/p〉〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Biology and Biochemistry, Volume 136〈/p〉 〈p〉Author(s): Tong Li, Zhaojun Bu, Wenyan Liu, Mingying Zhang, Changhui Peng, Qiuan Zhu, Shengwei Shi, Meng Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Despite the global importance of understanding the effects of nitrogen (N) and phosphorus (P) deposition on carbon (C) cycling in northern peatlands, the control of N and P interactions through the ‘enzymatic latch’ mechanism has been largely overlooked. A long-term fertilization experiment in a moderate-rich fen in northeast China was conducted to evaluate the underlying mechanisms of how continuous N and P addition regulate key extracellular enzymes and their interactions, and the subsequent influences on organic C storage in peatlands. The results demonstrated that the growth of 〈em〉Sphagnum〈/em〉 moss and vascular plants were both reduced by N addition but enhanced by P addition. Phenolic concentrations were higher in P addition treatments, as were phenol oxidase activities. In general, N addition played a critical role in regulating the stoichiometry of β-D-glucosidase, N-acetyl-β-glucosaminidase and phosphatase, while P addition was more important in regulating their activities. The direct and indirect effects due to fertilization and shifts in vegetational composition, respectively, weakened the ‘enzymatic latch’ mechanism that controls the decomposition of organic matter after long-term fertilization. Our results indicate that P likely plays a more important role than N in controlling microbial extracellular enzymatic activities and organic matter decomposition in northern minerotrophic peatlands. Consequently, the interactions between N and P is likely of primary significance in regulating the biogeochemical cycling of peatlands.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S003807171930183X-egi10WNNXH55H4.jpg" width="295" alt="Image 10554" title="Image 10554"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volumes 276–277〈/p〉 〈p〉Author(s): Jianxi Huang, Jose L. Gómez-Dans, Hai Huang, Hongyuan Ma, Qingling Wu, Philip E. Lewis, Shunlin Liang, Zhongxin Chen, Jing-Hao Xue, Yantong Wu, Feng Zhao, Jing Wang, Xianhong Xie〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Timely monitoring of crop lands is important in order to make agricultural activities more sustainable, as well as ensuring food security. The use of Earth Observation (EO) data allows crop monitoring at a range of spatial scales, but can be hampered by limitations in the data. Crop growth modelling, on the other hand, can be used to simulate the physiological processes that result in crop development. Data assimilation (DA) provides a way of blending the monitoring properties of EO data with the predictive and explanatory abilities of crop growth models. In this paper, we first provide a critique of both the advantages and disadvantages of both EO data and crop growth models. We use this to introduce a solid and robust framework for DA, where different DA methods are shown to be derived from taking different assumptions in solving for the 〈em〉a posteriori〈/em〉 probability density function (pdf) using Bayes’ rule. This treatment allows us to provide some recommendation on the choice of DA method for particular applications. We comment on current computational challenges in scaling DA applications to large spatial scales. Future areas of research are sketched, with an emphasis on DA as an enabler for blending different observations, as well as facilitating different approaches to crop growth models. We have illustrated this review with a large number of examples from the literature.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volumes 276–277〈/p〉 〈p〉Author(s): Wenjuan Shen, Mingshi Li, Chengquan Huang, Tao He, Xin Tao, Anshi Wei〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Estimating the effects of large scale afforestation is essential for the accurate understanding of its potential for the mitigation of climate warming. We used satellite observations to quantify the effects of the conversion of open lands (i.e., grassland and cropland) and natural forests to plantation forests and their associated biophysical processes (i.e., albedo and evapotranspiration (ET)) on land surface temperature (LST) in Guangdong Province, China. The hypothetical change (mean 2002–2018 values of LST difference between plantation forests and nearby lands in 2010) using the moving window searching-based method and actual change (changes of afforested area affecting the LST difference from 2000 to 2010) using the spatial pattern change trend method were detected in order to characterize the spatiotemporal variations in surface temperature, related albedo, and ET. The relationships between albedo, ET, and surface temperature change were also determined in combination with interpolated air temperature and precipitation. Results showed that the two methods-based afforestation changes had a similar net cooling effect, but a discrepancy in diurnal, seasonal, and spatial variations occurred. Overall, the actual change of afforested area led to a cooling effect by an average of −0.18 ± 0.02 °C, especially from croplands, which was greater than the air temperature. Individually, afforestation in the mid-subtropical forest zone (north of 24 °N, northern Guangdong) had a warming effect, especially during the transition from natural forests to plantation forests. We also observed an increase in cooling for the tropical forest zone across latitudes. Warming during the dry season was triggered by the albedo from plantation forests, but the albedo-induced forest cover change impacts on LST were quite complex. Meanwhile, ET dominated the cooling during the wet season and warm season. Additionally, enhanced precipitation played a more prominent role in the ET-induced cooling. Evaluation of the effect of temperature change induced by afforestation illustrates the importance of protecting natural forests and avoiding extensive artificial afforestation, especially in northern Guangdong Province, and reverting agricultural land to forest, especially in western Guangdong Province. This analysis also provides a basis for feedback from forest management activities to climate change in southern China.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geoderma, Volume 352〈/p〉 〈p〉Author(s): Sibylle Faust, Heinz-Josef Koch, Rainer Georg Joergensen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Undisturbed soils columns were transplanted from three tillage treatments at four sites in Central Germany to one site to investigate the relations between the CO〈sub〉2〈/sub〉 efflux, soil temperature (T〈sub〉S〈/sub〉) and volumetric water content (VWC) over one year in an unplanted period and maize (〈em〉Zea mays〈/em〉 L.) planted period. No tillage and grubber, i.e. rigid‑tine cultivator, (10-15 cm) systems contain higher stocks of microbial biomass C (MBC) in comparison with mouldboard ploughing (25-30 cm). This must be due to a reduction in microbial turnover, because higher VWC reduces T〈sub〉S〈/sub〉. At 5 cm depth, VWC was lowest with plough tillage throughout the year. At 15 cm depth, VWC was highest with grubber tillage during the planted period. During the unplanted period, mean T〈sub〉S〈/sub〉 was generally highest with grubber tillage. During the planted period, mean difference in T〈sub〉S〈/sub〉 increased in the order no tillage 〈 plough 〈 grubber at 5 cm depth and in the order plough 〈 grubber 〈 no-tillage at 15 cm depth. Mean CO〈sub〉2〈/sub〉 efflux was 1.12 t C ha〈sup〉−1〈/sup〉 in the unplanted and 2.85 t C ha〈sup〉−1〈/sup〉 in the planted period. Multiple linear relationships showed that T〈sub〉S〈/sub〉 and VWC explained 70.4% of the variance in CO〈sub〉2〈/sub〉 evolution rates in the unplanted and 37.2% in the planted period. T〈sub〉S〈/sub〉 effects generally dominated and showed similar regression coefficients in both periods. VWC had smaller effects, which were positive in the unplanted period and negative in the planted period. Significant tillage × T〈sub〉S〈/sub〉 interactions were observed in the unplanted period and tillage × VWC interactions in the planted period. Interactions were caused by strong positive T〈sub〉S〈/sub〉 effects with grubber tillage in the unplanted period and by strong negative VWC effects with plough tillage in the planted period. From a soil ecological viewpoint, grubber and no tillage can be recommended, as it improves microbial life conditions.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geoderma, Volume 353〈/p〉 〈p〉Author(s): Shangqi Xu, Xia Liu, Xiujun Li, Chunjie Tian〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Wetland restoration has been conducted worldwide due to the important ecological functions provided by wetlands. However, the global patterns of soil organic carbon (SOC) change following wetland restoration are not clear, which has limited the efficacy of the management of restored wetlands. In this study, we synthesized the results from 41 studies and carried out a meta-analysis to examine the SOC dynamics following wetland restoration and the underlying mechanisms. The SOC of restored wetlands was 13.8% (〈em〉p〈/em〉 = 0.017) higher than that of cultivated wetlands and 29.2% (〈em〉p〈/em〉 〈 0.001) lower than that of natural wetlands. Wetland restoration facilitated SOC sequestration under certain conditions, including when the wetlands were restored via water supplementation, had seasonal hydrology in their natural status (before cultivation), were peatlands, occurred under a temperate climate, were restored for 6 to 10 years, or had been cultivated no longer than 15 years before restoration. Meanwhile, some conditions had negative effects on SOC sequestration, including wetlands under a tropical climate, those restored using a plantation approach, and those with a tidal hydrology after restoration. Model selection analysis suggested that the hydrological conditions of cultivated wetlands, soil depth, vegetation type, peat condition and restored age were important influential factors affecting SOC after wetland restoration, with the first 2 being the most important influential factors. Our results indicate that wetland restoration is inefficient in terms of SOC recovery and that wetland restoration to recover SOC is urgently needed and should be conducted more appropriately. The results of this study provide theoretical support for wetland management with the aim of SOC sequestration.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geoderma, Volume 353〈/p〉 〈p〉Author(s): Xiaoting Xie, Yili Lu, Tusheng Ren, Robert Horton〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Information on soil thermal properties is needed for estimating soil temperature (〈em〉T〈/em〉) and heat flux. However, few datasets are available for assessing the effects of soil thermal diffusivity (κ) parameterization on diurnal 〈em〉T〈/em〉 estimations. In this study, three κ parameterization methods, all based on soil physical properties, are compared for determining the responses of 〈em〉Τ〈/em〉 estimation to κ on two field soils. Among the three methods, two are the combination of the de Vries heat capacity model with either the McCumber and Pielke thermal conductivity model (MP-D) or the Johansen thermal conductivity model (J75-D), and the other one is the Xie et al. κ model (X18). The harmonic approach was used to estimate 〈em〉T〈/em〉 in the 0- to 5-cm layer on a sandy loam soil, and in the 5- to 10-cm layer on a silty clay loam soil from the measured 〈em〉T〈/em〉 data at a single depth. The J75-D and X18 methods produced close κ values, while the κ values from the MP-D method deviated significantly from that of other models. The 〈em〉T〈/em〉 results from the J75-D and X18 based harmonic methods agreed well with 〈em〉T〈/em〉 measurements. On the sandy loam soil, 〈em〉T〈/em〉 estimates from the MP-D method had a RMSE (root mean square error) of 3.04 °C and an RSR (ratio of RMSE to the standard deviation of the observations) of 0.53, while smaller RMSE and RSR values were obtained from the X18 method (1 °C and 0.17) and J75-D method (0.8 °C and 0.14). For the silty clay loam soil, the RMSE and RSR of 〈em〉T〈/em〉 estimates from the MP-D-based harmonic method were 0.82 °C and 0.27, respectively, which were larger than those (0.57 °C and 0.19) of the X18 and J75-D-based harmonic method. We concluded that the X18 and J75-D based harmonic methods could provide more accurate soil profile 〈em〉Τ〈/em〉 estimates than the MP-D method.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geoderma, Volume 353〈/p〉 〈p〉Author(s): Thiago Leite de Alencar, Arilene Franklin Chaves, Alcione Guimarães Freire, Ícaro Vasconcelos do Nascimento, Alexandre dos Santos Queiroz, Jaedson Cláudio Anunciato Mota〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Field capacity (FC) is one of the most cited soil physical parameters and is relevant for the management of agricultural systems. In the search for alternatives to the estimation of FC, several researchers have proposed methods based on dynamic and static criteria. Evaluating these methods within a range of soil textural classes is important for prospects of their uses with higher water use efficiency. Based on the hypothesis that FC for a certain soil textural class is exclusively associated with an equivalent pore diameter, 〈em〉D〈/em〉-〈em〉threshold〈/em〉, which separates structural and textural porosity, and that textural pores define the FC conditions, this study aimed to: 1) estimate the equivalent pore diameter (〈em〉D〈/em〉-〈em〉threshold〈/em〉) which defines FC in each soil textural class in situ and, with the change of density, from the alterations in its water characteristic curve - WCC; 2) estimate the water content at FC in each soil textural class in situ and, with the change of density, from the alterations in its WCC. To obtain the water content corresponding to FC in situ, instantaneous profile-type experiments were conducted in five soil textural classes. To estimate FC and 〈em〉D〈/em〉-〈em〉threshold〈/em〉 based on the change in pore volume (CPV), soil water characteristic curves were used considering two situations: before and after compaction. Correlation and regression analyses were carried out between 〈em〉D〈/em〉-〈em〉threshold〈/em〉 and sand percentage, between water content at FC and the fitting parameters α and 〈em〉n〈/em〉 of the model of van Genuchten (1980), and between the value of the tangent at the inflection point of the soil WCC and the parameter α. By comparing 〈em〉D〈/em〉-〈em〉threshold〈/em〉 values obtained by the field and CPV methods, it was possible to observe that for the range of textural classes analyzed, in general, 〈em〉D〈/em〉-〈em〉threshold〈/em〉 values obtained by CPV were different from those obtained in situ. Therefore, the methodological procedure CPV does not represent the actual 〈em〉D〈/em〉-〈em〉threshold〈/em〉 of the FC found under field conditions. The values of water content corresponding to FC obtained by the CPV protocol are not due to the physical aspect conceived in the method's proposal. Thus, since these values were not due to the 〈em〉D〈/em〉-〈em〉threshold〈/em〉, this protocol cannot be indicated because it became evident that there was no clear cause-effect relationship. It was concluded that: 1) the principle of the method of estimating FC must be consistent with processes occurring in the soil. Since FC is dependent on soil processes, and associated with a drainage rate, there is no good reason why the CPV method correctly estimates the attribute; 2) the water content at FC in a certain soil textural class is not exclusively associated with only one equivalent pore diameter, 〈em〉D〈/em〉-〈em〉threshold〈/em〉, so the hypothesis assumed in the study has not been confirmed; and 3) protocols based on soil water dynamics should preferentially be used to estimate FC, to the detriment of methods based on static criteria.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Pengfei Chu, Libo He, Cheng Yang, Wencheng Zeng, Rong Huang, Lanjie Liao, Yongming Li, Zuoyan Zhu, Yaping Wang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Autophagy is an essential and conserved process that plays an important role in physiological homeostasis, adaptive response to stress and the immune response. Autophagy-related proteins (ATGs) are key components of the autophagic machinery. In the study, grass carp (〈em〉Ctenopharyngodon idella〈/em〉) autophagy-related gene 5 (〈em〉ATG5〈/em〉) and 12 (〈em〉ATG12〈/em〉) were identified. In the gill and intestine, 〈em〉ATG5〈/em〉 and 〈em〉ATG12〈/em〉 were highly expressed, but after grass carp reovirus (GCRV) infection, they were decreased significantly. In 〈em〉Ctenopharyngodon idella〈/em〉 kidney (CIK) cells, the sharp variation of 〈em〉ATG5〈/em〉 and 〈em〉ATG12〈/em〉 expression was observed after poly(I:C) infection. Subcellular localisation showed that ATG5 and ATG12 were evenly distributed in the cytoplasm and nucleus. However, the interaction between ATG5 and ATG12 was only found in cytoplasm in both 293T cells and CIK cells. In addition, the overexpression of ATG5 or ATG12 in 293T cells showed enhanced autophagy, and autophagic process was facilitated when ATG5 and ATG12 were simultaneously overexpressed. Dual-luciferase activity assay indicated that both ATG5 and ATG12 remarkably suppressed the promoter activity of 〈em〉IRF3〈/em〉, 〈em〉IRF7〈/em〉, and 〈em〉IFN-I〈/em〉. Further, ATG5 and ATG12 conjugate showed far stronger inhibitory affection on the expression of 〈em〉IFN-I〈/em〉 than either ATG5 or ATG12 in response to poly(I:C) or GCRV infection. Taken together, the results demonstrate that grass carp ATG5 and ATG12 play an important role in innate immunity and autophagy.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Chao Xu, Wen-Bin Liu, Sofie Charlotte Remø, Bing-Ke Wang, Hua-Juan Shi, Li Zhang, Jia-Dai Liu, Xiang-Fei Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study investigated the effects of restricted feeding on the growth performance, oxidative stress and inflammation of 〈em〉Megalobrama amblycephala〈/em〉 fed high-carbohydrate (HC) diets. Fish (46.94 ± 0.04 g) were randomly assigned to four groups containing the satiation of a control diet (30% carbohydrate) and three satiate levels (100% (HC1), 80% (HC2) and 60% (HC3)) of the HC diets (43% carbohydrate) for 8 weeks. Results showed that HC1 diet remarkably decreased final weight (FW), weight gain rate (WGR), specific growth rate (SGR), feed conversion ratio (FCR), hepatic activities of total anti-oxidation capacity (T-AOC), superoxide dismutase (SOD) and catalase (CAT), the AMP/ATP ratio, the p-AMPKα/t-AMPKα ratio, sirtuin-1 (SIRT1) protein expression and hepatic transcriptions of AMPKα2, SIRT1, nuclear factor erythroid 2-related factor 2 (Nrf2), catalase (CAT), manganese superoxide dismutase (Mn-SOD), glutathione peroxidase 1 (GPx1) and interleukin10 (IL 10) compared to the control group, whereas the opposite was true for protein efficiency ratio (PER), nitrogen retention efficiency (NRE), energy retention efficiency (ERE), plasma glucose levels, alanine transaminase (AST) and aspartate aminotransferase (ALT) activities, hepatic contents of malondialdehyde (MDA), tumour necrosis factor α (TNF α) and interleukin 1β (IL 1β), ATP and AMP contents and hepatic transcriptions of kelch-like ECH associating protein 1 (Keap1), IkB kinase α (IKK α), nuclear factor kappa B (NF-κB), TNF α, IL 1β, interleukin 6 (IL 6) and transforming growth factor β (TGF β). As for the HC groups, fish fed the HC2 diet obtained relatively high values of SGR, PER, NRE, ERE, hepatic activities of T-AOC, SOD and CAT, the AMP/ATP ratio, the p-AMPKα/t-AMPKα ratio, SIRT1 protein expression and hepatic transcriptions of AMPKα2, Nrf2, CAT, copper/zinc superoxide dismutase (Cu/Zn-SOD), Mn-SOD, GPx1, glutathione S-transferase (GST) and interleukin10 (IL 10), while the opposite was true for hepatic content of IL 6 and transcription of IKK α. Overall, an 80% satiation improved the growth performance and alleviated the oxidative stress and inflammation of blunt snout bream fed HC diets via the activation of the AMPK-SIRT1 pathway and the up-regulation of the activities and transcriptions of Nrf2-modulated antioxidant enzymes coupled with the depression of the levels and transcriptions of the NF-κB-mediated pro-inflammatory cytokines.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): Jiangfan Zhang, Chuanju Dong, Junchang Feng, Junpeng Li, Shengjie Li, Jianxin Feng, Xiaodi Duan, Gaigai Sun, Peng Xu, Xuejun Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉〈em〉HIFs〈/em〉 (Hypoxia inducible factors) are the main regulators of the expression change of oxygen-dependent genes, in addition, they also play important roles in immune regulation. 〈em〉HIFs〈/em〉 participate in infectious diseases and inflammatory responses, providing us a new therapeutic target for the treatment of diseases. In this study, 16 〈em〉HIFs〈/em〉 were identified in common carp genome database. Comparative genomics analysis showed large expansion of 〈em〉HIF〈/em〉 gene family and approved the four round whole genome duplication (WGD) event in common carp. To further understand the function of 〈em〉HIFs〈/em〉, the domain architectures were predicted. All HIF proteins had the conserved HLH-PAS domain, which were essential for them to form dimer and bind to the downstream targets. The differences in domain of HIFα and HIFβ might result in their different functions. Phylogenetic analysis revealed that all 〈em〉HIFs〈/em〉 were divided into two subfamilies and the 〈em〉HIFs〈/em〉 in common carp were clustered with their teleost counterparts indicating they are highly conservative during evolution. In addition, the tissue distribution was examined by RT-PCR showed that most of 〈em〉HIF〈/em〉 genes had a wide range of tissue distribution but exhibited tissue-specific expression patterns. The expression divergences were observed between the copy genes, for example, 〈em〉HIF1A-1〈/em〉, 〈em〉HIF2A-1〈/em〉, 〈em〉ARNT-〈/em〉2 had wide tissue distribution while their copies had limited tissue distribution, proving the function divergence of copies post the WGD event. In order to find an effective activation of 〈em〉HIFs〈/em〉 and apply to treatment of aquatic diseases, we investigate the dietary supplementation effects of different strains of 〈em〉Lactococcus lactis〈/em〉 on the expression of 〈em〉HIFα〈/em〉 subfamily members in kidney of common carp infected with 〈em〉A. hydrophila〈/em〉. In addition, all of the 〈em〉HIF〈/em〉 genes have a high expression in the early stages of infection, and decreased in the treatment time point of 48 h in common carp. This phenomenon confirms that as a switch, the main function of 〈em〉HIFs〈/em〉 is to regulate the production of immune response factors in early infection. So activation of the switch may be an effective method for infectious disease treatment. As expected, the treatment groups improved the expression of 〈em〉HIFs〈/em〉 compared with the control group, and the effects of the three strains are different. The strain1 of 〈em〉L. lactis〈/em〉 had a stronger induction on 〈em〉HIF〈/em〉 genes than strain2 and strain3, and it might be applied as a potential activation of 〈em〉HIF〈/em〉 genes for disease treatment. So, adding befitting 〈em〉L. lactis〈/em〉 maybe a well method to activate the 〈em〉HIF〈/em〉 genes to protect them from mycobacterial infection.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 92〈/p〉 〈p〉Author(s): K.A.S.N. Shanaka, M.D. Neranjan Tharuka, Thanthrige Thiunuwan Priyathilaka, Jehee Lee〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Viperin, also known as RSAD2 (Radical S-adenosyl methionine domain containing 2), is an interferon-induced endoplasmic reticulum-associated antiviral protein. Previous studies have shown that viperin levels are elevated in the presence of viral RNA, but it has rarely been characterized in marine organisms. This study was designed to functionally characterize rockfish viperin (〈em〉SsVip〈/em〉), to examine the effects of different immune stimulants on its expression, and to determine its subcellular localization. SsVip is a 349 amino acid protein with a predicted molecular mass of 40.24 kDa. It contains an S-adenosyl 〈span〉l〈/span〉-methionine binding conserved domain with a CNYKCGFC sequence. Unchallenged tissue expression analysis using quantitative real time PCR (qPCR) revealed 〈em〉SsVip〈/em〉 expression to be the highest in the blood, followed by the spleen. When challenged with poly I:C, 〈em〉SsVip〈/em〉 was upregulated by approximately 60-fold in the blood after 24 h, and approximately 50-fold in the spleen after 12 h. Notable upregulation was detected throughout the poly I:C challenge experiment in both tissues. Significant expression of 〈em〉SsVip〈/em〉 was detected in the blood following 〈em〉Streptococcus iniae〈/em〉 and lipopolysaccharide challenge, and viral hemorrhagic septicemia virus (VHSV) gene transcription was significantly downregulated during SsVip overexpression. Furthermore, cell viability assay and virus titer quantification with the presence of SsVip revealed a significant reduction in virus replication. As with previously identified viperin counterparts, SsVip was localized in the endoplasmic reticulum. Our findings show that SsVip is an antiviral protein crucial to innate immune defense.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Marine Policy, Volume 107〈/p〉 〈p〉Author(s): Carmen Pedroza-Gutiérrez〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Lake Chapala's fisheries have been an important economic activity for hundreds of years. However, the introduction of carpe and tilapia forced a change in the market structure, including the processing-value-adding-activities. Currently, filleting-fish is a successfully growing industry, which employs mostly women from the coastal communities. This paper aims to identify the factors influencing the division of labor in fish-processing and the determinants of bargaining-power for women. Fieldwork was carried out between 2015 and 2017 in three communities bordering Lake Chapala, Mexico (Jamay, Petatán, LaPalma), using a survey strategy based on questionnaires and formal and informal interviews to obtain qualitative and quantitative data. Findings show that fish-processing as a labor market opportunity for women is a source of bargaining power, working hours are flexible, and it is a constant and reliable source of income, unlike fishing. In each community the gender division of labor is constructed according to the local culture and the gendered-social-norms. In Petatán, fish-processing is a woman dominated activity, highly valued, with the largest average income, complementary to household income. Jamay has male (20%) and female (80%) fish-processors, fish-processing is their only source of income, and is considered an activity for single mothers (35%) or those who do not have access to better jobs. In both communities, married women's contribution to household income depends on their husband's daily earnings ranging between 25 and 75%. In LaPalma, fish-processing is a male-dominated activity, where women do not dare to work among the young filleting workers, who are breadwinners.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil and Tillage Research, Volume 194〈/p〉 〈p〉Author(s): Eunice Essel, Junhong Xie, Chaochao Deng, Zhengkai Peng, Jinbin Wang, Jicheng Shen, Jianhui Xie, Jeffrey A. Coulter, Lingling Li〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Soil microbial diversity is important in maintaining soil quality, sustainable agriculture, and ecosystem function. Soil management practices can influence the diversity and activity of soil microbes in agricultural fields. The objective of this study was to assess the effects of tillage and stubble management on the diversity of bacteria and fungi, chemical property and total carbon emission in the rhizosphere and bulk soils in wheat (〈em〉Triticum aestivum〈/em〉 L.) -pea (〈em〉Pisum arvense〈/em〉 L.) rotation at pre-harvest. Treatments included conventional tillage with stubble removed (T), no-tillage with stubble removed (NT), conventional tillage with stubble incorporated (TS), and no-tillage with stubble retained (NTS). Bacteria 16S rRNA (V3V4) and fungi ITS (ITS2) region genes were sequenced from bulk soil and rhizosphere soils. Abundance of the dominant bacterial (Actinobacteria, Proteobacteria, Chloroflexi, Acidobacteria, and Planctomycetes) and fungal (Ascomycota and Basidiomycota) phyla identified did not differ significantly (〈em〉P〈/em〉 〈 0.05) among treatments. 〈em〉Rhizobium〈/em〉 and rare fungi 〈em〉Kurtzmanomyces〈/em〉 occurred in the rhizosphere but were virtually absent in bulk soil. However, bacterial and fungal OTUs diversity indices were less in the rhizosphere compared to bulk soil. Soil from the NTS and NT had the greatest bacteria 16S rRNA and fungi ITS region number of OTUs; however, the microbial community did not differ among treatments. The abundance of class level bacteria and fungi were associated with soil pH, total organic carbon, total nitrogen, NH〈sub〉4〈/sub〉〈sup〉+〈/sup〉 -N, and NO〈sub〉3〈/sub〉〈sup〉¯〈/sup〉 -N contents. The results indicate that bulk soil had higher microbial library, which will be beneficial for establishment of the next season’s microbial community.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agriculture, Ecosystems & Environment, Volume 284〈/p〉 〈p〉Author(s): Libo Sun, Xiaomin Chang, Xinxiao Yu, Guodong Jia, Lihua Chen, Ziqiang Liu, Xuhui Zhu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Shelter forests in the agricultural field are critical ecological barriers against harsh environmental conditions and agricultural soil erosion in northern China; however, shelter forests have been extensively degraded in the past decades. It is unknown how patterns of mortality of shelter forests relate to highly variable spatial precipitation and soil water content (SWC). Here, we explore the relationships of precipitation and SWC with the mortality of 〈em〉Populus simonii〈/em〉 Carr (poplar) shelter forests in the semi-arid Bashang Plateau, northern China. Mortality of poplar shelter forests and its relationship with precipitation and SWC are spatially quantified in an area with an uneven distribution of precipitation by combining standard field plot measurements, precipitation, and SWC spatial distribution grid data. The mortality patterns of poplar shelter forests revealed threshold responses to precipitation and SWC, with lower mortality (〈32%) above 230 mm (precipitation) and an SWC 〉 16.56%. Results indicate that a threshold response is evident when precipitation is 60% of the average precipitation. In addition, our results show that wind speed, low temperature, and stand density also had significant effects on the mortality of poplar shelter forests. Our results show how precipitation and SWC patterns within a region influence the mortality of poplar shelter forests. Moreover, this study reveals other factors influencing stand structure and landscape heterogeneity, which have been largely overlooked in previous studies.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Forest Ecology and Management, Volume 448〈/p〉 〈p〉Author(s): Miaomiao Zhao, Jilin Yang, Na Zhao, Yu Liu, Yifu Wang, John P. Wilson, Tianxiang Yue〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Forests are a major contributor of terrestrial ecosystem carbon pools. Accurate estimates of forest biomass carbon sinks can improve our understanding of carbon cycles and help in developing sustainable forest management policies in the face of climate change. In this study, we update estimates of the biomass carbon stocks of China’s forests based on seven forest inventory datasets from 1977 to 2013 and carbon fraction coefficients of 46 tree species in the continuous biomass expansion factor (CBEF) model. Our findings suggest that: (1) China’s forest stands acted as an average biomass carbon sink of 99.07 Tg C year〈sup〉−1〈/sup〉; and (2) biomass carbon stocks increased by 72.62% from 1977 to 2013 and recently reached 7.27 Pg C, driven by forest area expansion and forest growth. The biomass carbon density of forest stands (canopy coverage 〉20%) increased from 38.18 to 44.52 Mg C ha〈sup〉−1〈/sup〉 during the study period, with higher carbon densities in natural compared to planted forests, and the gap increasing with forest age. The largest increases in the biomass of carbon stocks of forest stands occurred in the eastern and northern regions. Our results suggest that biomass carbon stocks of natural forests account for about 85% in the most recent inventory and that the total biomass carbon stocks of forest stands in China will keep increasing in the future because of the large area of planted forests with young and middle-aged forest growth. The results from this study can help with comprehensive investigations of forest carbon budgets and the calibration and validation of simulation model results.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Forest Ecology and Management, Volume 448〈/p〉 〈p〉Author(s): Steffen Herrmann, Markus O. Huber, Zoe Bont, Andreas Rigling, Jan Wunder〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Wood decay limits the function of Norway spruce (〈em〉Picea abies〈/em〉 (L.) H.Karst.) for wood production and in protection forests (i.e. forests protecting against natural hazards). Therefore, more detailed knowledge about the presence and extent of decay in living trees is highly relevant for both the timber industry and risk management strategies. However, decay detection in living Norway spruce trees is not sufficiently possible by visual methods. One possibility to overcome this problem are indirect, non- or least-destructive measurement devices such as the decay detector Rotfinder. Yet, the influence of climatic variables on the reliability of decay detection determined with the Rotfinder is not sufficiently known. Therefore, we assessed the influences of several climatic variables on the Rotfinder values continuously over one year at the same measuring position. Additionally, we determined a threshold value for decay detection in single Norway spruce trees in Central Europe. Regardless of the temperature, Rotfinder values measured over one year were mainly influenced by internal decay status, i.e. damage degree, which explained about 85% of the variation based on a generalized linear mixed effects model in this temperature range (about 6–27 °C). Together with fluctuations in air temperature, about 87% of the variation in Rotfinder values could be accounted for. For decay detection in single Norway spruce trees, a maximum threshold value of about 11,000 Rotfinder units (RU) was identified, equivalent to about 36% of the Rotfinder values measured for intact trees. Our results indicate that the Rotfinder can be used successfully for decay detection in single Norway spruce trees under Central European conditions.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Forest Ecology and Management, Volume 448〈/p〉 〈p〉Author(s): Raul Rosenvald, Piret Lõhmus, Riinu Rannap, Liina Remm, Katrin Rosenvald, Kadri Runnel, Asko Lõhmus〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Retention forestry is a silvicultural approach that can achieve both ecological and economic objectives in various forest ecosystems. It builds largely on the assumption that the live trees left unharvested (the main timber cost) effectively support ecological functioning of post-harvest forest. Such effectiveness can be understood as a combination of the initial ecological value of the tree (that may persist after tree death) and its survival, i.e., the prospect to develop into a high-quality veteran tree in the next forest generation. We assessed those aspects among 〉3000 live trees actually retained in 103 Estonian harvested sites and monitored over 16 years. We analysed how their survival and habitat value (estimated from tree morphology, confirmed by epiphyte surveys) translate to the veteran-tree perspectives. Only 48% of the trees were still alive after 16 years, and this final survival at the stand-scale was poorly predictable from a few years of monitoring. Only 12% retention trees had both high habitat value and high survival. Most trees (75%) were of low initial habitat value and, combined with low survival, almost 40% of all trees never provided quality habitat for tree-dwelling species. Nevertheless, we found considerable potential for post-harvest development of habitat value; notably in European nemoral hardwood species (such as 〈em〉Fraxinus, Quercus, Ulmus, Acer〈/em〉), which survived well but were usually in subcanopies at the time of the harvest. These findings indicate that retention forestry can improve also highly impoverished (e.g. short-rotation) forests, if analytical tools have been developed and applied to predict tree survival and future habitat quality.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Forest Ecology and Management, Volume 448〈/p〉 〈p〉Author(s): Quanzhi Zhang, Chuankuan Wang, Zhenghu Zhou〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Quantifying net primary production (NPP) and its allocation is essential for understanding and modeling the carbon (C) cycling in forest ecosystems. We used biometry-based measurements to examine the NPP allocation for six temperate forest types with similar stand age and climate but diverse stand characteristics and site conditions in northeastern China. The forest types included four naturally-regenerated stands and two planted stands. Our objectives were to (1) compare the NPP and its allocation among the six forest types, and (2) explore the factors driving the inter-stand variability of the NPP allocation patterns. We found that the total NPP (TNPP) and NPP of short-lived biomass tissues (NPP〈sub〉SL〈/sub〉) differed significantly among the forest types, varying from 709 to 927 gC m〈sup〉−2〈/sup〉 yr〈sup〉−1〈/sup〉 and from 364 to 594 gC m〈sup〉−2〈/sup〉 yr〈sup〉−1〈/sup〉, respectively. However, the NPP of long-lived tissues (NPP〈sub〉LL〈/sub〉) did not differ significantly among the forest types, varying from 305 to 364 gC m〈sup〉−2〈/sup〉 yr〈sup〉−1〈/sup〉. These results suggested that the production of structural tissues be relatively stable under the same climate, and the inter-stand difference in TNPP be mainly attributed to the difference in NPP〈sub〉SL〈/sub〉. Within the four natural stands, the foliage production was significantly and positively correlated with soil nitrogen (N) (〈em〉R〈/em〉〈sup〉2〈/sup〉 = 0.50) and phosphorus (P) stock (〈em〉R〈/em〉〈sup〉2〈/sup〉 = 0.37), whereas the fine root production was significantly and negatively correlated with soil C:P (〈em〉R〈/em〉〈sup〉2〈/sup〉 = 0.54) and N:P ratio (〈em〉R〈/em〉〈sup〉2〈/sup〉 = 0.47), implying that foliage and root production may be driven by different mechanisms. The convergence of NPP〈sub〉LL〈/sub〉 across forest types with different stand characteristics, site conditions and management practices but under the same climate has important implication in managing forest ecosystems for C sequestration, while the divergence of NPP〈sub〉SL〈/sub〉 implies that vegetation can adapt to the site conditions by changing resource-absorbing tissues production and its allocation.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Marine Policy, Volume 108〈/p〉 〈p〉Author(s): Maurice Beseng〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This article removes the lid on fisheries crime in Cameroon by providing empirical evidence of criminal practices along the maritime fisheries value chain. To achieve this, the study relied on both primary and secondary data. Primary data was collected from direct observation, informal group discussions and semi-structured interviews involving state officials, coastal community groups and other civil society organisations in the west maritime district of Southwest Cameroon. The article reveals a plethora of fisheries-related crimes encompassing corruption (i.e. bribery and abuse of office), document and identity fraud, illegal exploitation of fish maws and endangered marine mammals. Other crimes associated to the fisheries sector included: smuggling of contraband goods, arms smuggling, illegal migration, illegal recruitment and abuse of workers' rights. Through these examples, this research empirically demonstrates the interrelationship of the different criminal practices and their organised and transnational dimension. The study also paints a complex picture of criminality perpetuated by a sophisticated network of both local and foreign industrial fisheries stakeholders. Consequently, addressing illicit activities in the maritime fisheries sector requires cooperation from a wide range of both state and non-state actors in investigating and analysing the nature of fisheries crime practices, the agents involved and their modes of operation. This approach is necessary to gain a better understanding of the problem and enable actors design appropriate and targeted management responses.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Marine Policy, Volume 108〈/p〉 〈p〉Author(s): André S. Afonso, Leonardo L. Fidelis, Pedro L. Roque, Renato Galindo, Wanderson Dionisio, Leonardo B. Veras, Fábio H.V. Hazin〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Marine Protected Areas (MPAs) are potentially effective conservation and management instruments yet they often produce socioeconomic conflicts which may challenge their success. Knowledge and perceptions about environmental subjects among MPA residents were examined to identify possible effects of conservation policies upon local communities. Sharks were used as a proxy for wildlife given their local relevance and socioenvironmental context. Self-administered questionnaires were used to collect data from 134 randomly-selected residents of Fernando de Noronha (FEN), Brazil. Affinity towards nature tended to decrease among people 〉44 years old, whereas 〉10 years residents were more associated with negative feelings about sharks. Homogeneity in knowledge was noticed but perceptions decreased conspicuously across residence time-classes. Only 33% of respondents reported unarguable MPA benefits to local welfare, while several problems pertaining to infrastructure, management and resources were mentioned. These results are worrisome because they might translate into growing frustration along with residence time, which could potentially jeopardize the success of conservation policies. Wildlife conservation and at least partial improvements to welfare being positively signalized by a relevant proportion of respondents suggest an encouraging potential for relationship improvement between MPAs and stakeholders. Nonetheless, the long-term sustainability of inhabited MPAs could depend on properly integrating human users and ensuring their support and compliance, which must be considered while designing management strategies. Given the prestige of FEN in the South Atlantic and worldwide, it is important that this MPA delivers successful, sustainable outcomes that can be representative of efficient conservation trajectories to be replicated elsewhere.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Marine Policy, Volume 108〈/p〉 〈p〉Author(s): Sara Hornborg, Ingrid van Putten, Camilla Novaglio, Elizabeth A. Fulton, Julia L. Blanchard, Éva Plagányi, Cathy Bulman, Keith Sainsbury〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Ecosystem-based fisheries management (EBFM) is a globally mandated approach with the intention to jointly address ecological and human (social-cultural, economic and institutional) dimensions. Indicators to measure performance against objectives have been suggested, tested, and refined but with a strong bias towards ecological indicators. In this paper, current use and application of indicators related to the human dimension in EBFM research and ecosystem models are analysed. It is found that compared to ecological counterparts, few indicators related to the human dimension are commonly associated with EBFM, and they mainly report on economic objectives related to fisheries. Similarly, in the most common ecosystem models, economic indicators are the most frequently used related to the human dimension, both in terms of model outputs and inputs. The prospect is small that indicators mainly related to profitable fishing economy are able to report on meeting the broad range of EBFM objectives and to successfully evaluate progress in achieving EBFM goals. To fully conform with EBFM principles, it is necessary to recognise that ecological and human indicators are inter-dependent. Moreover, the end-to-end ecosystem models used in EBFM will need to be further developed to allow a fuller spectrum of social-cultural, institutional, and economic objectives to be reported against.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Forest Ecology and Management, Volume 452〈/p〉 〈p〉Author(s): Alicia Calle, Karen D. Holl〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉To meet their large-scale forest and landscape restoration targets, countries must find ways to accommodate areas for conservation alongside agricultural production. In some pasture-dominated regions of Latin America, intensive silvopastoral systems (SPS) are being promoted to increase cattle productivity on certain lands while facilitating the removal of cattle from marginal areas for forest restoration. However, the recovery of these forests and their contribution to the overall conservation value of the landscape has not been assessed rigorously. We evaluated forest structure and composition in 20 sites in a region of the Colombian Andes where a decade ago farmers transitioned to SPS and fenced off riparian areas to enable forest recovery. We compared these restored forests to a reference model based on the remaining riparian forest across the region, all of which has been subjected to human management. We found that woody species richness was higher in restored than in reference forests, and the proportion of large-seeded, later successional, animal-dispersed species were similar in both forest types. Whereas we found a similar suite of dominant tree species in restored and reference forest, 〈em〉Guadua angustifolia〈/em〉, a native giant bamboo was more abundant in the reference forests due to human management. Total tree basal area was higher in restored forests due to a small number of very large trees likely present in the pastures at the time of site protection. These findings highlight (1) the potential for recovery of diverse forests in riparian sites despite previous grazing use and (2) the role of remnant trees in facilitating natural succession. Overall, rapid forest recovery with minimal intervention in previously farmed lands is good news for conservation in a region that still harbors significant biodiversity despite high levels of fragmentation and the influence of human management.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agriculture, Ecosystems & Environment, Volume 283〈/p〉 〈p〉Author(s): Nadine Kraemer, Gerd Dercon, Pedro Cisneros, Felipe Arango Lopez, Camilla Wellstein〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The cultivation of marginal land in the Andes makes it one of the hot-spots of soil erosion. Since the 1980s an alternative soil conservation method denominated “slow-forming terraces” has been introduced to the area, since it is not labour or cost intensive and therefore more likely to be applied by the small-holder farmers. Research investigating the short-term effect on soil properties and crop productivity in these terrace systems showed reason for concern regarding the sustainability of the method, since there were position-dependent drops in crop productivity and related soil properties especially on shallow soils. Here, we investigate in the same terrace systems the temporal change of the observed properties 21 years after establishment. The terraces are managed by subsistence farmers and thus provide a valuable insight: if the spatial heterogeneity disappears, this renders slow-forming terraces agronomically sustainable in the long-term. Our results show a significant improvement of soil properties in general and furthermore to most extent a disappearance of the spatial heterogeneity in plant properties. These findings outline that the initial disadvantages of this soil conservation practice can be overcome in the long-term making slow-forming terraces a valuable measure for soil conservation and a sustainable system for small-holder subsistence farming. A support in farm planning, informing about both short- and long-term agronomic effects, while also considering social, economic and cultural/traditional aspects, could increase the adoption and maintenance of conservation measures and also symbiotically increase family income.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 September 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Forest Ecology and Management, Volume 448〈/p〉 〈p〉Author(s): Joseph Langridge, Benoît Pisanu, Sébastien Laguet, Frédéric Archaux, Laurent Tillon〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Forests constitute one of the most important feeding and foraging habitats for bats. Because bat populations are declining, most likely due to habitat loss or fragmentation, it is imperative to understand the issues concerned with timber exploitation on bat conservation. We investigated the foraging activity of edge- and open-space foragers in relation to stand and vegetation structure, characteristics that are commonly affected by forestry. Acoustic surveys, culminating to 713 point count sites were undertaken covering 46 different forest massifs across mainland France over 6 years. We used generalized linear mixed models to analyse the activity of ten species: 6 edge-habitat and 4 open-habitat foragers. 〈em〉Pipistrellus pipistrellus〈/em〉 was the most detected edge-habitat forager, while 〈em〉Nyctalus leisleri〈/em〉 was the most recorded of the open-habitat foragers. 〈em〉Eptesicus serotinus〈/em〉 and 〈em〉P. pipistrellus〈/em〉 responded positively to heterogeneous vertical vegetation volume. In addition, 〈em〉P. kuhlii〈/em〉 and 〈em〉P. nathusii〈/em〉 responded negatively to tree basal area. 〈em〉Barbastella barbastellus〈/em〉, 〈em〉Hypsugo savii〈/em〉, and 〈em〉P. nathusii〈/em〉 were associated with either ground deadwood and/or logging tracks and minor-traffic roads, confirming the importance of edge space. Finally, 〈em〉B. barbastellus, E. serotinus,〈/em〉 and 〈em〉P. nathusii〈/em〉 were positively linked to the presence of tree microhabitats. This study demonstrates that bat use in forests is complex and multifaceted. Maintaining ground deadwood and heterogeneity of vegetation, at the forest plot scale, should ensure the ecological functioning of exploited forest systems and the conservation of edge- and open-habitat foraging bats.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geoderma, Volume 353〈/p〉 〈p〉Author(s): Yanan Huang, Jaivime Evaristo, Zhi Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Interpretation of groundwater recharge mechanisms is problematic because of the muted instantaneous response of subsurface water to rainfall and limited recharge rates, particularly in semi-arid environments with deep loess deposits. Here we identify the possible groundwater recharge mechanisms in 200-m thick loess deposits with unsaturated zone thickness of over 40 m. We collected soil samples up to 15 m deep under four land use types (one grassland and three apple orchards with stand ages 15, 24 and 30 years old), and used three-year precipitation and groundwater samples to determine the contents of stable water isotopes, chloride, and tritium. Our overarching goal is to determine the relative importance of piston and preferential flow in groundwater recharge using multiple tracers and quantify the effects of land use change on groundwater recharge. We find that while both piston and preferential flows are important in groundwater recharge, the unsaturated and saturated zones have yet to come to hydraulic equilibrium. This suggests different groundwater recharge mechanisms: tracers in the unsaturated zone suggest piston flow, while the detectable tritium in the saturated zone implies preferential flow. Recharge rates in the unsaturated zones range between 23 and 82 mm year〈sup〉−1〈/sup〉, accounting for 4%–14% of mean annual precipitation, and increasing with depth presumably because of land use and/or climatic conditions. Total recharge rate in the saturated zone is 112.6 ± 44.1 mm year〈sup〉−1〈/sup〉, accounting for 19 ± 9% of mean annual precipitation. Overall, our study finds that piston flow contributes more to total recharge (53%–69%) than does preferential flow. Nevertheless, piston flow may become less important because of land use change (farmland to apple orchard conversion). Our findings have implications for the need to strike a delicate balance between the economic gains from afforestation and the possible risks to groundwater supply sustainability.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geoderma, Volume 353〈/p〉 〈p〉Author(s): Lei Deng, Changhui Peng, Chunbo Huang, Kaibo Wang, Qiuyu Liu, Yulin Liu, Xuying Hai, Zhouping Shangguan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Soil extracellular enzymatic activity (EEA) stoichiometry could reflect the biogeochemical equilibrium between the metabolic requirements of microbial communities and environmental nutrients availability. However, the drivers of soil microbial metabolic limitation (SMML) changes remain poorly understood following vegetation restoration. We compared sites along a vegetation restoration chronosequence over a 30-year period on the Loess Plateau, China, and measured the potential activities of two C-acquiring enzymes (β-1,4-glucosidase (BG) and β-〈span〉d〈/span〉-cellobiosidase (CBH)), two N-acquiring enzymes (β-1,4-〈em〉N〈/em〉-acetylglucosaminidase (NAG) and 〈span〉l〈/span〉-leucine aminopeptidase (LAP)), and one organic-P-acquiring enzyme (alkaline phosphatase (AP)), to quantify and compare the variations in metabolic limitations for soil microorganisms using EEA stoichiometry. The results showed constant microbial P limitation, but not N limitation, and an open downward “unimodal” trend in microbial C limitation; however, the microbial P limitation displayed exactly the opposite trend during vegetation restoration. Restoration age and properties of plant, soil, and microorganisms contributed to 82.9% of microbial C limitation and 84.6% of microbial P limitation, with soil presenting the highest relative effects of 76.1% and 59.6% on microbial C and P limitations, respectively. Plant productivity and species diversity decreased microbial C limitation owing to increasing plant C inputs, but increased microbial P limitation owing to plant nutrients competition with soil microorganisms. When the fungi:bacteria ratio in the soil increased, the SMML increased. Vegetation restoration increased the soil nutrients content and reduced SMML, and a decrease in the soil water content increased microbial P limitation. Thus, the effects of long-term vegetation restoration on SMML were the result of combined influences of plants, soil, and microorganisms.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Jing Li, Zhi-Bin Wu, Zhao Zhang, Ji-Wei Zha, Shen-Ye Qu, Xiao-Zhou Qi, Gao-Xue Wang, Fei Ling〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Nowadays, there is no suitable treatment for vibriosis in groupers. So an eco-efficient and environmentally friendly treatment is necessary for the grouper industry. Probiotic-feeding has been a promising strategy to control the bacterial pathogens in aquaculture. A new 〈em〉Bacillus velezensis〈/em〉 strain named K2 was isolated from the intestinal tract of healthy grouper, and exhibited wide antimicrobial spectrum of against fish pathogens, including 〈em〉Vibrio harveyi〈/em〉, 〈em〉Vibrio alginolyticus〈/em〉, 〈em〉Aeromonas hydrophila〈/em〉, 〈em〉Aeromonas veronii〈/em〉, 〈em〉Aeromonas caviae〈/em〉, 〈em〉Enterococcus casseliflavus〈/em〉 and 〈em〉Lactococcus garvieae〈/em〉. Moreover, results of the safety of 〈em〉B. velezensis〈/em〉 K2 showed that intraperitoneal injection of K2 in healthy grouper did not cause any pathological abnormality or death, indicating this bacteria could be considered as a candidate probiotic in aquaculture. Groupers were fed with the diets containing 1 × 10〈sup〉7〈/sup〉 cfu/g of 〈em〉B. velezensis〈/em〉 K2 for 4 weeks. Various immune parameters were examined at 1, 2, 3, and 4 weeks of post-feeding. Results showed that diets supplemented with K2 significantly increased serum acid phosphatase (ACP) activity (〈em〉P〈/em〉 〈 0.05). Results of the mRNA expression of immune-related genes in the head kidney of hybrid grouper showed that the expression of lysozyme gene was significantly upregulated after 1 and 2 weeks of feeding (〈em〉P〈/em〉 〈 0.05). A significant up-regulation of the expression of piscidin, IgM and MyD88 were detected at day 21, whereas the TLR3 and TLR5 showed lower expression compared to the controls during 21 days, and a significant decrease of TLR3 gene was found at day 28 (〈em〉P〈/em〉 〈 0.05). After challenge with 〈em〉V. harveyi〈/em〉, the survival rate of fish administrated with the strain K2 for 28 days was signifiacantly higher than the controls without this strain (〈em〉P〈/em〉 〈 0.05). These results collectively suggest that 〈em〉B. velezensis〈/em〉 K2 is a potential probiotic species to improve health status and disease resistance and can be developed as a probiotic agent in grouper industry.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Phennapa Promthale, Pattira Pongtippatee, Boonsirm Withyachumnarnkul, Kanokpan Wongprasert〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Fishmeal is the main source of protein in the shrimp feed industry and is normally derived from trash fish. As such, the production of fishmeal has an adverse effect on the marine environment by taking away small and juvenile fish, leading to depletion of marine species. There is a need for alternative sources of protein which will substitute fishmeal in the aquaculture industry. This study evaluated the components and nutritional efficacy of bioflocs, which were used to substitute fishmeal protein. The effect of bioflocs diets on growth performance, survival rate, and immune response in shrimp compared to normal fishmeal feed were determined. Bioflocs were harvested from the shrimp ponds (C:N ratio 〉12:1) at Shrimp Village, Chaiya district, Surat Thani, Thailand. The total protein in bioflocs was about 48% and the total lipid was about 5% (dried weight) and the percentages of essential amino acids (EAA) and fatty acids (EFA) in bioflocs were similar to those of fishmeal feed. Shrimp fed with the different dietary bioflocs feed regimens [% to replace fishmeal; 0% (B0), 25% (B25), 50% (B50), 75% (B75), and 100% (B100)] for 42 days revealed that all growth parameters were almost similar to those of the control shrimp (shrimp fed with normal fishmeal, B0) including final body weight, weight gain, specific growth rate, and feed conversion ratio. Remarkably, the survival rates, the levels of immune parameters, and expression of immune genes (proPO-I, PEN-4 and dicer) were significantly higher in bioflocs fed shrimp, especially in B25 and B50 shrimp. Moreover, B25 and B50 bioflocs fed shrimp showed notably increased survival rates following 〈em〉Vibrio parahaemolyticus (V. parahaemolyticus)〈/em〉 infection. In conclusion, the present study demonstrates that shrimp survival and immunity are enhanced by biofiocs substituted fishmeal. Significantly, the bioflocs diets activated the immune response to prevent 〈em〉V. parahaemolyticus〈/em〉 infection.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Sarah J. Poynter, Shanee Herrington-Krause, Stephanie J. DeWitte-Orr〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In mammals, the multifunctional DExH/D-box helicases, DDX3 and DHX9, are nucleic acid sensors with a role in antiviral immunity; their role in innate immunity in fish is not yet understood. In the present study, full-length DDX3 and DHX9 coding sequences were identified in rainbow trout (〈em〉Oncorhynchus mykiss)〈/em〉. Bioinformatic analysis demonstrated both deduced proteins were similar to those of other species, with ~80% identity to other fish species and ~70–75% identity to mammals, and both protein sequences had conserved domains found amongst all species. Phylogenetic analysis revealed clustering of DDX3 and DHX9 with corresponding proteins from other fish. Cellular localization of overexpressed DDX3 and DHX9 was performed using GFP-tagged proteins, and endogenous DDX3 localization was measured using immunocytochemistry. In the rainbow trout gonadal cell line, RTG-2, DHX9 localized mostly to the nucleus, while DDX3 was found mainly in the cytoplasm. Tissue distribution from healthy juvenile rainbow trout revealed ubiquitous constitutive expression, highest levels of DDX3 expression were seen in the liver and DHX9 levels were fairly consistent among all tissues tested. Stimulation of RTG-2 cells revealed that DDX3 and DHX9 transcripts were both significantly upregulated by treatment with the dsRNA molecule, poly I:C. A pull-down assay suggested both proteins were able to bind dsRNA. In addition to their roles in RNA metabolism, the conserved common domains found between the rainbow trout proteins and other species having defined antiviral roles, combined with the ability for the proteins to bind to dsRNA, suggest these proteins may play an important role in fish innate antiviral immunity. Future studies on both DDX3 and DHX9 function will contribute to a better understanding of teleost immunity.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 94〈/p〉 〈p〉Author(s): Ke-Cheng Zhu, Hua-Yang Guo, Nan Zhang, Bao-Suo Liu, Liang Guo, Shi-Gui Jiang, Dian-Chang Zhang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Interferon regulatory factor 8 (IRF8) increases type I IFN transcription levels by binding to IFN promoters, thereby playing a role in innate immunity. Nevertheless, the detailed mechanism through which IRF8 regulates type II IFN in fish remains ambiguous. In the present study, two genes from the golden pompano (〈em〉Trachinotus ovatus〈/em〉), 〈em〉IRF8〈/em〉 (〈em〉ToIRF8〈/em〉) and 〈em〉IFN gamma〈/em〉 (〈em〉ToIFNγ〈/em〉), were identified in the IFN/IRF-based signalling pathway. The full-length 〈em〉ToIRF8〈/em〉 cDNA was composed of 2,141 bp and encoded a 421 amino acid polypeptide; the genomic DNA was 2,917 bp in length and consisted of 8 exons and 7 introns. The putative protein showed the highest sequence identity (90–92%) with fish IRF8 and possessed a DNA-binding domain (DBD), an IRF-association domain (IAD) and a nuclear localization signal (NLS) motif consistent with those of IRF8 in other vertebrates. Furthermore, the 〈em〉ToIRF8〈/em〉 transcripts were expressed in all examined tissues of healthy fish, with higher levels observed in the central nervous and immune relevant tissues. They were upregulated by polyinosinic acid: polycytidylic acid [poly (I: C)], lipopolysaccharide (LPS) and flagellin treatments in the blood, liver, intestine and kidney. The results from assays of subcellular localization showed that 〈em〉ToIRF8〈/em〉 was localized to the cytoplasm. Moreover, to investigate whether ToIRF8 was a regulator of 〈em〉ToIFNγ〈/em〉, a promoter analysis was performed using progressive deletion mutations of 〈em〉ToIFNγ〈/em〉. The results indicated that the region from −601 bp to −468 bp includes the core promoter. Mutation analyses indicated that the activity of the 〈em〉ToIFNγ〈/em〉 promoter significantly decreased after the targeted mutation of the M1-M3 binding sites. Additionally, overexpressed 〈em〉ToIRF8〈/em〉 in vitro notably increased the expression of several IFN/IRF-based signalling pathway genes. These results suggest that 〈em〉IRF8〈/em〉 is vital in the defence of 〈em〉T. ovatus〈/em〉 against bacterial infection and contributes to a better understanding of the transcriptional mechanisms of ToIRF8 on type II IFN in fish.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Marine Policy, Volume 108〈/p〉 〈p〉Author(s): J. Ford, D. Clark〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Arctic is undergoing transformative climate change, with profound implications for transportation safety in marine areas. Circumpolar marine risks are growing due to ship traffic increases linked to more ice-free open water, as well as increases in hazards for individuals that frequently travel on ice and trails in the region. While recent Government of Canada policies have attempted to respond to the growing risk of marine and coastal emergencies, there is strong evidence that the federal government and communities along Canada's Arctic coast are minimally prepared for the emerging risks. In this Short Communication, we argue that Canada is falling short of its international and national obligations to provide timely search and rescue across the Arctic, to the detriment of Arctic communities. Drawing from recently published reports and literature, we argue that providing additional training, resources, and support for volunteer SAR groups across the region is critical, along with increasing federal air and marine resources committed to the region. Such investments need underpin Canada's approach to climate change adaptation in the North.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil and Tillage Research, Volume 195〈/p〉 〈p〉Author(s): Bin Zhang, Aizhen Liang, Zhanbo Wei, Xueli Ding〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Soils simultaneously provide multiple ecosystem functions (i.e. multifunctionality) which are of critical importance in terms of climate regulation and fertility maintenance. Although the influence of tillage practices on many soil functions is well documented, its effect on the resistance and resilience of these functions to climate change from a ‘holistic ecosystem’ view remains poorly understood. In this study, we compared the resistance and resilience to dry-wet cycles, which is predicted to be more frequent and intensified in agricultural soils under climate change, of soil multifunctionality under no-tillage and ridge tillage. We found that no-tillage led to a higher resistance but a lower resilience of soil multifunctionality than ridge tillage in response to dry-wet disturbances. Variation partitioning analysis and mantel correlation between dissimilarity matrices showed that the resistance and resilience of soil multifunctionality was closely related to soil microbial diversity. Soil pH also contributed to the variation in stability of soil multifunctionality, but its explanatory power was much lower than microbial diversity. Our results suggest that tillage practices strongly affect the resistance and resilience of soil multifunctionality to dry-wet cycles, which might exert important consequences for ecosystem services that delivered by agricultural soils under climate change.〈/p〉〈/div〉

Description: 〈p〉Publication date: December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil and Tillage Research, Volume 195〈/p〉 〈p〉Author(s): Zihao Wu, Bozhi Wang, Junlong Huang, Zihao An, Ping Jiang, Yiyun Chen, Yanfang Liu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The spatial distribution of soil organic carbon density (SOCD) is crucial for understanding land use impact on carbon budget. The spatial estimation and accurate mapping of SOCD in plains remain challenging, partly due to the relatively invariant topography and the lack of consideration of landscape patterns. Here, we propose a novel landscape metric-based regression Kriging (LMRK) for the spatial estimation of SOCD in plains. Using 242 topsoil samples collected in the Jianghan Plain, China, we (i) investigate the scale-dependent relationship between SOCD and 24 landscape metrics and (ii) develop LMRK models with multi-scale buffers (100–1000 m) for SOCD estimation and compare their performance with ordinary Kriging (OK) and regression Kriging (RK) that integrates land use types. Results showed that LMRK outperformed other models. The relationships between SOCD and landscape metrics were found to be scale-dependent, and the buffer of 300 m exhibited the optimal scale in our case. The LMRK also revealed that a highly connected and water-sufficient landscape was conducive to the accumulation of soil organic carbon in farmlands. These results indicated that landscape metrics serve as good predictors, and the proposed LMRK method is effective for SOCD mapping in plains. Our findings highlight the scale-dependent relationship between landscape metrics and SOCD and provide a new perspective for soil mapping in plains.〈/p〉〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Tetsuro Ikuta, Akihiro Tame, Masaki Saito, Yui Aoki, Yukiko Nagai, Makoto Sugimura, Koji Inoue, Katsunori Fujikura, Kazue Ohishi, Tadashi Maruyama, Takao Yoshida〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In symbiotic systems in which symbionts are transmitted horizontally, hosts must accept symbionts from the environment while defending themselves against invading pathogenic microorganisms. How they distinguish pathogens from symbionts and how the latter evade host immune defences are not clearly understood. Recognition of foreign materials is one of the most critical steps in stimulating immune responses, and pattern recognition receptors (PRRs) play vital roles in this process. In this study, we focused on a group of highly conserved PRRs, peptidoglycan recognition proteins (PGRPs), in the deep-sea mussel, 〈em〉Bathymodiolus septemdierum〈/em〉, which harbours chemosynthetic bacteria in their gill epithelial cells. We isolated 〈em〉B. septemdierum〈/em〉 PGRP genes 〈em〉BsPGRP-S〈/em〉 and 〈em〉BsPGRP-L〈/em〉, which encode a short- and a long-type PGRP, respectively. The short-type PGRP has a signal peptide and was expressed in the asymbiotic goblet mucous cells in the gill epithelium, whereas the long-type PGRP was predicted to include a transmembrane domain and was expressed in gill bacteriocytes. Based on these findings, we hypothesize that the secreted and transmembrane PGRPs are engaged in host defence against pathogenic bacteria and/or in the regulation of symbiosis via different cellular localizations and mechanisms.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Guilherme Rabelo Coelho, Pedro Prezotto Neto, Fernanda Cortinhas Barbosa, Rafael Silva Dos Santos, Patrícia Brigatte, Patrick Jack Spencer, Sandra Coccuzzo Sampaio, Fernanda D’Amélio, Daniel Carvalho Pimenta, Juliana Mozer Sciani〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Stingrays skin secretions are largely studied due to the human envenoming medical relevance of the sting puncture that evolves to inflammatory events, including necrosis. Such toxic effects can be correlated to the biochemical composition of the sting mucus, according to the literature. Fish skin plays important biological roles, such as the control of the osmotic pressure gradient, protection against mechanical forces and microorganism infections. The mucus, on the other hand, is a rich and complex fluid, acting on swimming, nutrition and the innate immune system. The elasmobranch's epidermis is a tissue composed mainly by mucus secretory cells, and marine stingrays have already been described to present secretory glands spread throughout the body. Little is known about the biochemical composition of the stingray mucus, but recent studies have corroborated the importance of mucus in the envenomation process. Aiming to assess the mucus composition, a new non-invasive mucus collection method was developed that focused on peptides and proteins, and biological assays were performed to analyze the toxic and immune activities of the 〈em〉Hypanus americanus〈/em〉 mucus. Pathophysiological characterization showed the presence of peptidases on the mucus, as well as the induction of edema and leukocyte recruitment in mice. The fractionated mucus improved phagocytosis on macrophages and showed antimicrobial activity against 〈em〉T. rubrumç. neoformans〈/em〉 and 〈em〉C. albicans in vitro〈/em〉. The proteomic analyses showed the presence of immune-related proteins like actin, histones, hemoglobin, and ribosomal proteins. This protein pattern is similar to those reported for other fish mucus and stingray venoms. This is the first report depicting the 〈em〉Hypanus〈/em〉 stingray mucus composition, highlighting its biochemical composition and importance for the stingray immune system and the possible role on the envenomation process.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Forest Ecology and Management, Volume 451〈/p〉 〈p〉Author(s): Thomas P. Sullivan, Druscilla S. Sullivan〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Restoration practices are much needed on clearcut openings in commercial forest landscapes where some mammal species have declined in abundance from a loss of preferred food, cover, and other components of stand structure. Retention of excess woody debris in piles and windrows provides habitat for forest-floor small mammals and some of their predators such as small mustelids. However, it is unknown if these retention habitats are used over longer periods (〉10 years) as new forests grow and develop on harvested sites, or do they become unoccupied? We tested the hypotheses (H) that (H〈sub〉1〈/sub〉) abundance, species richness, and diversity of the forest-floor small mammal community, and (H〈sub〉2〈/sub〉) reproduction and survival of the southern red-backed vole (〈em〉Myodes gapperi〈/em〉), long-tailed vole (〈em〉Microtus longicaudus〈/em〉), and deer mouse (〈em〉Peromyscus maniculatus〈/em〉) would decline on sites with woody debris structures, compared with sites of dispersed woody debris or uncut forest, up to 12 years post-construction in south-central British Columbia, Canada.〈/p〉 〈p〉Woody debris structures provided habitat on new clearcuts for 〈em〉M. gapperi〈/em〉 at comparable or higher abundance than in uncut forest and 5.0 to 7.6 times higher than on dispersed sites in the first 5-year period. Although numbers declined after the initial three years, populations of 〈em〉M. gapperi〈/em〉 in debris structures recovered to earlier abundance levels at 11–12 years post-construction. Mean abundance of 〈em〉M. longicaudus〈/em〉 was consistently higher (2.8 to 3.5 times) in piles and windrows than in sites with dispersed woody debris over the first 5-year period. Populations of 〈em〉M. longicaudus〈/em〉 were high in all three treatment sites at 11 years post-construction reaching mean annual peak numbers of 24, 42, and 36 voles per ha in the dispersed, piles, and windrow sites, respectively. Mean abundance of 〈em〉P. maniculatus〈/em〉 was similar among treatment sites and consistent over time. Mean abundance of total small mammals was consistently higher (1.8 to 2.4 times) in piles and windrows than dispersed or forest sites in the first 5-year period and this pattern was continued at 11–12 years post-construction. At 11 years post-construction, all treatment sites had the highest peak numbers per ha in the study: dispersed (40.3), piles (64.1), windrows (56.1), and forest (29.0). Our results did not support H〈sub〉1〈/sub〉 as abundance, species richness, and diversity were increased or maintained in the debris structures over the 12-year period. Reproduction and survival followed the pattern of abundance for the major species, and hence H〈sub〉2〈/sub〉 was not supported. Our study is the first to measure long-term (up to 12 years) responses of forest-floor small mammals to constructed piles and windrows of woody debris as a means of habitat retention on clearcuts. These mammalian species, particularly voles, may then serve as prey for marten and other mustelids. This relationship provides further support for piles and windrows to act as baseline trophic structures in ecological restoration of cutover forest land.〈/p〉 〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Forest Ecology and Management, Volume 451〈/p〉 〈p〉Author(s): Halina Smal, Sławomir Ligęza, Jacek Pranagal, Danuta Urban, Dorota Pietruczyk-Popławska〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The objective of this study was to investigate the effect of afforestation of post-arable sandy soils (Dystric Arenosols) with Scots pine (〈em〉Pinus sylvestris〈/em〉 L.) on the amount and distribution of C〈sub〉org〈/sub〉, N〈sub〉tot〈/sub〉 and P〈sub〉tot〈/sub〉 stocks between genetic soil horizons. The study was performed at three locations with five classes of afforestation each: 10-, 20-, 30-, 40-, 50-year-old stands, which additionally included the arable and the continuous forest soils as reference. The soil was sampled by genetic horizon, including the organic one, down to 100 cm, from its whole thickness, and from A horizon of the afforested soils from: 0–5, 5–10 and 10–20 cm. In the organic horizon of the afforested soils, the stock of C〈sub〉org〈/sub〉, N〈sub〉tot〈/sub〉 and P〈sub〉tot〈/sub〉 increased significantly with stand age, and an average rate of accumulation was 33.6, 1.30 and 0.04 g m〈sup〉−2〈/sup〉 year〈sup〉−1〈/sup〉 respectively. C〈sub〉org〈/sub〉 stocks in the former plough layer were found to decrease within the first decade of afforestation, and subsequently, the values gradually increased. With organic horizon included the respective stocks reached the level comparable with the related horizon of the arable soil after approx. 20–30 years. Subsoil B, BC and C horizons together accounted for approx. 35% of the C〈sub〉org〈/sub〉 stocks in the entire profile. N〈sub〉tot〈/sub〉 stocks in mineral soil horizons initially dropped in the first decade after afforestation, which was subsequently followed by an increase; however, after 50 years, still the observed values were lower in comparison with both the respective arable and continuous forest soils. P〈sub〉tot〈/sub〉 stocks in the mineral soil horizon declined over the chronosequence, and in the profile at 50-year-old stands, they were lower in comparison with both the arable and the continuous forest soils. Stand age and sampling by genetic horizons, including the organic horizon, from the entire soil profile should be considered for estimation of changes in C〈sub〉org〈/sub〉, N〈sub〉tot〈/sub〉 and P〈sub〉tot〈/sub〉 stocks following afforestation of agricultural soils.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 278〈/p〉 〈p〉Author(s): Alison Donnelly, Rong Yu, Lingling Liu, Jonathan M. Hanes, Liang Liang, Mark D. Schwartz, Ankur R. Desai〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Changes in the timing and duration of spring leaf development have implications for the start of the carbon uptake period and are therefore fundamental to the accurate calculation of carbon budgets, and in determining the potential for forests to sequester CO〈sub〉2〈/sub〉. Here, we examined trends in CO〈sub〉2〈/sub〉 exchange (Net Ecosystem Exchange (NEE), Gross Primary Production (GPP) and Ecosystem Respiration (ER)) (1997–2016) and satellite derived measures (Enhanced Vegetation Index (EVI) and modeled Leaf Area Index (LAI)) of the start of spring from the MODIS product MOD13Q1 (2001–2016) for a mixed forest landscape in northern Wisconsin, USA. We then explored the relationship between these indirect determinants of spring phenology and the timing and duration of spring phenophases (bud-burst, leaf-out, full-leaf unfolded) of trees over a 5-year period (2006–2010). Contrary to earlier studies focus’, our analysis did not find a consistent link between the early transition, of the forest stand from C source to sink with increased annual productivity. Interestingly, while annual regional NEE trended from a source to a sink over the study period, there were no significant concomitant trends in the timing of the start of the season, peak season or the duration of the season derived from (i) satellite data (2001–2016), (ii) flux data (1997–2016) nor from 〈em〉in situ〈/em〉 observations (2006–2010). The range of time periods used and difference in phenological determinants examined likely contributed to a lack of expected relationships. The results highlight the need for 〈em〉in situ〈/em〉 observations of different forest layers, in particular shrubs, which could help explain current discrepancies between direct and indirect determinants of spring phenology. Furthermore, characterization of abiotic influences on C flux measurements may further explain some of the observed discrepancies.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 278〈/p〉 〈p〉Author(s): Ping Yue, Qiang Zhang, Liang Zhang, Hongyu Li, Yang Yang, Jian Zeng, Sheng Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Estimating seasonal and interannual variations in energy partitioning and actual evapotranspiration (〈em〉ET〈/em〉) distributions in semiarid grasslands is essential for improving the understanding of interactions between the land and atmosphere, and is useful for land surface parameterization in grasslands of the Loess Plateau. In this study, energy fluxes and 〈em〉ET〈/em〉 values over a semiarid grassland site and their environmental and biological controls were investigated over multiple years (2007–2012) using the eddy covariance method. The seasonal and interannual variations in the partitioning of the net radiation (〈em〉R〈/em〉n) into sensible (〈em〉H〈/em〉) and latent (〈em〉LE〈/em〉) heat fluxes were primarily controlled by precipitation through changes in the soil water content (〈em〉SWC〈/em〉) and vegetation growth. During relatively wet and warm periods, 〈em〉LE〈/em〉 was the dominant component of the energy balance, whereas 〈em〉H〈/em〉 was the dominant component of energy partitioning in dry periods. Annual 〈em〉ET〈/em〉 was higher than annual 〈em〉P〈/em〉 (except in 2007), with a better closure of surface energy balance during the drier years. The total annual 〈em〉ET〈/em〉 and its daily maximum varied from 278.2 to 460.3 mm and from 3.45 to 4.95 mm day〈sup〉−1〈/sup〉, respectively. The daily Priestley-Taylor coefficient (〈em〉ET〈/em〉/〈em〉ET〈/em〉〈sub〉eq〈/sub〉, where 〈em〉ET〈/em〉〈sub〉eq〈/sub〉 is the equilibrium evaporation) decreased sharply when the 〈em〉SWC〈/em〉 in the 5-cm soil layer decreased below 0.15 m〈sup〉3〈/sup〉 m〈sup〉-3〈/sup〉 during the growing seasons. The average 〈em〉ET〈/em〉 for sixteen days was linearly correlated with the normalized difference vegetation index (〈em〉NDVI〈/em〉). 〈em〉ET〈/em〉/〈em〉ET〈/em〉〈sub〉eq〈/sub〉 increased nonlinearly with an increase in 〈em〉Gs〈/em〉 but was insensitive to the increases in 〈em〉Gs〈/em〉 greater than 6.52 mm s〈sup〉−1〈/sup〉 in the driest year (2011) and 9.17 mm s〈sup〉−1〈/sup〉 in the wettest year (2007). Additionally, there is good correlation between the threshold of 〈em〉Gs〈/em〉 and the annual mean 〈em〉NDVI〈/em〉. On an annual scale, the low 〈em〉G〈/em〉s (3.07-6.77 mm s〈sup〉−1〈/sup〉), 〈em〉ET〈/em〉/〈em〉ET〈/em〉〈sub〉eq〈/sub〉 (0.28-0.42), and higher Bowen ratio (〈em〉β〈/em〉) (2.07–4.19) collectively represented the overall water-limited conditions for 〈em〉ET〈/em〉 in the semiarid grassland of the Loess Plateau. Our data indicate that 〈em〉ET〈/em〉 and its biophysical controls vary in response to interannual changes in annual 〈em〉P〈/em〉. These results contribute to an understanding of the driving mechanisms for long-term variations in energy partitioning and biophysical controls on 〈em〉ET〈/em〉 in the Loess Plateau of China.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 278〈/p〉 〈p〉Author(s): Pengpeng Duan, Qianqian Zhang, Xi Zhang, Zhengqin Xiong〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉A clear understanding of the effects of manure, biochar and nitrification inhibitors (NI, nitrapyrin-SNI and 〈em〉Sorghum bicolor〈/em〉 L.-BNI) amendment on nitrous oxide (N〈sub〉2〈/sub〉O) production pathways and consumption remains elusive under field conditions. A field experiment using an isotopocule mapping approach (δ〈sup〉15〈/sup〉N〈sup〉SP〈/sup〉〈sub〉N2O〈/sub〉 and δ〈sup〉18〈/sup〉O〈sub〉N2O/H2O〈/sub〉 map) in conjunction with molecular techniques were conducted to understand the mechanisms of these options for N〈sub〉2〈/sub〉O mitigation in a Tung choy (〈em〉Ipomoea aquatic〈/em〉 Forssk.) vegetable soil. The manure substitution and biochar not only decreased nitrification/fungal denitrification and bacterial denitrification/nitrifier denitrification-derived N〈sub〉2〈/sub〉O emission, but also stimulated N〈sub〉2〈/sub〉O reduction to N〈sub〉2〈/sub〉 during the denitrification process as evidenced from the decrease of ammonia-oxidizing bacteria (AOB) 〈em〉amoA〈/em〉 and the increase of 〈em〉nirS〈/em〉, 〈em〉nosZⅠ〈/em〉, 〈em〉nosZⅡ〈/em〉 and fungal 〈em〉nirK〈/em〉 transcripts. Biochar had a greater potential to enhance this reduction with decrease of ammonia-oxidizing archaea (AOA) 〈em〉amoA〈/em〉 transcripts. NIs mitigated the N〈sub〉2〈/sub〉O derived from nitrification and/or bacterial denitrification/nitrifier denitrification demonstrated from the simultaneous decrease of soil NO〈sub〉2〈/sub〉〈sup〉−〈/sup〉 and NO〈sub〉3〈/sub〉〈sup〉−〈/sup〉 and increase of soil NH〈sub〉4〈/sub〉〈sup〉+〈/sup〉 intensity together with the lower AOB 〈em〉amoA〈/em〉 transcripts in NIs than in the urea. These results helped explain the observed differences in N〈sub〉2〈/sub〉O emissions among these mitigation options, and laid the foundation for a better understanding of N〈sub〉2〈/sub〉O production and reduction under field conditions.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0168192319302801-ga1.jpg" width="321" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 278〈/p〉 〈p〉Author(s): Haozhou Wang, Dong Han, Yue Mu, Lina Jiang, Xueling Yao, Yongfei Bai, Qi Lu, Feng Wang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The change of fraction vegetation cover (FVC) is the key ecological index for vegetation dynamics of dryland ecosystem. However, it is difficult to directly map woody vegetation and herbaceous vegetation in the dryland from the satellite images due to the mixture of their distribution at small scale. Emerging UAV remote sensing provides a good opportunity to capture and quantify the distribution of the sparse vegetation in the drylands ecosystem. In this study, we proposed a new method to classify woody vegetation and herbaceous vegetation and calculate their FVC based on the high-resolution orthomosaic generated from UAV images by the machine learning algorithm of classification and regression tree (CART). This proposed method was validated and evaluated by visual interpretation, the detailed ground measurement dataset of 4832 trees and 18,798 shrubs and three popular machine learning algorithms of Support Vector Machine(SVM), Random Forest(RF), Gradient Boosting Decision Tree(GBDT). The overall assessments showed good overall accuracy (0.78), average accuracy (0.76), and the Kappa coefficient (0.64). The FVC of woody vegetation calculated from orthomosaic agreed well with that estimated from ground measurements. Both group of FVC have a stable linear relationship over different spatial scales. The proposed method showed higher efficiency of 166%, 111% and 290% than SVM, RF, GBDT respectively. A new optimized model was developed to reduce the workload of vegetation investigation and to design more efficient sampling strategies. The proposed method was incorporated into an interactive web-based software “UAV- High Resolution imagery Analysis Platform” (UAV-HiRAP, 〈a href="http://www.uav-hirap.org/" target="_blank"〉http://www.uav-hirap.org〈/a〉). Our study demonstrates that UAV-HiRAP combined with UAV platform can be a powerful tool to classify woody vegetation and herbaceous vegetation and calculate their FVC for sparse vegetation in the drylands. The new optimization model will inspire researchers to design more effective sampling strategies for future field investigation.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0168192319302734-ga1.jpg" width="493" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 278〈/p〉 〈p〉Author(s): Dominik Seidel, Martin Ehbrecht, Peter Annighöfer, Christian Ammer〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Management for complexity has become an important paradigm for European and North American forestry. Recent advancements in data processing allow for a detailed, three-dimensional and objective quantification of structural complexity in forests based on terrestrial laser scanning data. In our study, we used such 3D data from an exemplary temperate broad-leaved forest in Thuringia, Germany, to gain insights to the relationship between tree-level structural complexity and stand-level structural complexity. From our study site, which was 80 by 80 m in extent with a total of 215 trees growing in it, we created a dataset that contained each tree as an independent point cloud. Random sample plots of varying size (10 × 10 m; 15 × 15 m; 20 × 20 m) where used to create sub-plots (sampling with replacement) and to enable for the investigation of effects of scale. Our study revealed that plot-level complexity of plots up to 20 × 20 m is largely determined by the complexity of the most complex-structured tree individual. Furthermore, a high tree complexity and variability thereof in the stand was generally beneficial to stand structural complexity. Other individual tree characteristics, such as a large crowns, were also identified to have positive effects on plot-level complexity. We conclude that management for complexity should focus on large-crowned, highly-complex tree individuals as key elements of stand structural complexity. This indicates that large and old trees may not only be of great importance as habitat trees potentially increasing biodiversity, but also due to their contribution to the overall stand-level complexity.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 278〈/p〉 〈p〉Author(s): Katalin Anita Zagyvai-Kiss, Péter Kalicz, József Szilágyi, Zoltán Gribovszki〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Forest ecosystems typically have a large leaf-area index both within the crown level and on the ground as litter, making interception a very important element of the forest water balance. Broad information exists about crown interception, but relatively few data are available regarding litter interception. The litter layer is able to change the quantities of water available for soil infiltration and runoff, so the water holding capacity of the litter is an important parameter for hydrological modelling. In this study the water holding capacity of the litter for three species (spruce, beech, sessile oak) was determined under field conditions in the eastern foothills of the Alps. Litter data were produced through a collection of about 450–500 samples over two years (2003–2005). Although the litter oven-dry weights of the forest stands were different, the specific water holding capacities [litres per kg oven-dry weight] of the litter were near-identical for needle-leaf and broad-leaf forest ecosystems. According to our measurements, the specific water holding capacity of the litter is about 2.0–2.1 litres kg〈sup〉−1〈/sup〉 oven-dry weight, regardless of the tree species.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 278〈/p〉 〈p〉Author(s): Jiangong Liu, Derrick Y.F. Lai〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Coastal mangrove wetlands have an excellent potential in sequestrating atmospheric carbon dioxide (CO〈sub〉2〈/sub〉) owing to their high primary productivity as well as slow anaerobic decomposition of organic matter. Yet, there is hitherto a paucity of researches examining the temporal variations and environmental controls of ecosystem-scale CO〈sub〉2〈/sub〉 fluxes in subtropical mangroves using quasi-continuous, high temporal resolution measurements. In this study, we measured the net ecosystem CO〈sub〉2〈/sub〉 exchange (NEE) between the atmosphere and a subtropical estuarine mangrove dominated by 〈em〉Kandelia obovata〈/em〉 using an eddy covariance system for two full years to investigate the seasonal variability and key biophysical drivers of NEE. During the wet seasons, the magnitude of increase in ecosystem respiration (Re) was greater than that in gross primary productivity (GPP) owing to a combination of higher temperature and lower percentage of inundation, tidal height and water salinity, which subsequently resulted in an overall decrease in net CO〈sub〉2〈/sub〉 uptake as compared to the dry seasons. Our results of path analysis showed that temperature was a dominant control of the temporal variations in CO〈sub〉2〈/sub〉 flux during the wet seasons, while its influence became weaker during the dry seasons. On the other hand, an increase in water salinity during the dry seasons had a positive influence on GPP, which was likely related to a greater availability of ions (mainly Cl〈sup〉−〈/sup〉 and Na〈sup〉+〈/sup〉) in supporting photosynthesis by mangrove trees in this coastal wetland with relatively low salinity (∼5–15 ppt). Our subtropical mangrove wetland was shown to be a significant carbon (C) sink, with annual C uptake rates of 890 and 758 g CO〈sub〉2〈/sub〉-C m〈sup〉-2〈/sup〉 yr〈sup〉−1〈/sup〉 in the two years of study. We found a strong control of mangrove CO〈sub〉2〈/sub〉 fluxes by biophysical factors such as temperature and salinity, implying that global warming and a reduction in water salinity in response to a greater river discharge could potentially reduce the C sink strength of estuarine mangroves in the subtropical regions.〈/p〉〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S0168192319302527-ga1.jpg" width="276" alt="Graphical abstract for this article" title=""〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Applied Soil Ecology, Volume 143〈/p〉 〈p〉Author(s): Lijuan Ma, Huijuan Guo, Wei Min〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Shortage of fresh water resources has become a fundamental and chronic problem for sustainable agriculture development in arid regions. Use of saline water irrigation has become an important means for alleviating fresh water scarcity. However, long-term irrigation with saline water may cause salt accumulation in the soil, and further affect nitrogen transformation and N〈sub〉2〈/sub〉O emission. For this, we conducted a 10-year field experiment to evaluate the effect of irrigation water salinity and N amount on N〈sub〉2〈/sub〉O emission and denitrifier bacteria communities. The experimental design was a 2 × 2 factorial with two irrigation water salinity levels (0.35 and 8.04 dS m〈sup〉−1〈/sup〉, representing SF and SH) and two N amounts (0 and 360 kg N ha〈sup〉−1〈/sup〉, representing N0 and N360). The results indicated that long-term saline water irrigation significantly increased soil salinity, moisture, and NH〈sub〉4〈/sub〉-N content, while decreased soil pH, NO〈sub〉3〈/sub〉-N, organic matter, and total nitrogen. Irrigation with saline water significantly inhibited N〈sub〉2〈/sub〉O emission, that was associated with a level decreased by 45.19% (N0) and 43.50% (N360) compared with irrigation with fresh water. N〈sub〉2〈/sub〉O emission increased as the N amount increased, the N〈sub〉2〈/sub〉O emission was 161% higher in the N360 treatment than in the N0 treatment. In the unfertilized plots, saline water irrigation significantly reduced the activity of denitrifying enzymes, the abundance of nirK, nirS, and nosZ, as well as the diversity of denitrifying bacteria communities. In the fertilized plots, saline water irrigation did not significantly affect the abundance of nosZ, while significantly reduced the abundance of nirK and nirS. Saline water irrigation and nitrogen application altered the community structures of denitrifying bacteria with nirK, nirS, and nosZ, irrigation water salinity seemed to be having a greater impact on denitrifying bacteria community in comparison with fertilization. LEfSe analysis demonstrated denitrifying bacterial potential biomarkers increased as the water salinity increased, meaning that saline water irrigation could alter community structures of denitrifying bacteria, and promote the growth of dominant species. Our findings indicate that increased abundance of nosZ, nirK, and nirS would promote N〈sub〉2〈/sub〉O emission, and although long-term saline water reduced soil N〈sub〉2〈/sub〉O emission, it resulted in continuous increase of soil salinity.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil and Tillage Research, Volume 195〈/p〉 〈p〉Author(s): Haihou Wang, Mingxing Shen, Dafeng Hui, Ji Chen, Guofeng Sun, Xin Wang, Changying Lu, Jing Sheng, Liugen Chen, Yiqi Luo, Jianchu Zheng, Yuefang Zhang〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Crop straw management plays important roles in sustainable agriculture and environmental protection. Straw incorporation has multiple influences on soil organic carbon (SOC) sequestration, greenhouse gas (GHG) emissions, and crop yields, but these influences have rarely been studied simultaneously in a single cropping system. This study was conducted to examine the influence of long-term straw incorporation on the SOC sequestration rate, methane (CH〈sub〉4〈/sub〉) and nitrous oxide (N〈sub〉2〈/sub〉O) emissions and crop yields in a Chinese rice (〈em〉Oryza sativa〈/em〉 L.) –wheat (〈em〉Triticum aestivum〈/em〉 L.) cropping system in Hydragric Anthrosols under a subtropical monsoon climate. Four straw incorporation treatments were applied: wheat straw incorporation only (WS), rice straw incorporation only (RS), both wheat and rice straw incorporation (WSRS), and no straw incorporation (as a control). The SOC sequestration rate was estimated from the changes in SOC stock in the topsoil (0–20 cm) from 2007 to 2016. The emissions of CH〈sub〉4〈/sub〉 and N〈sub〉2〈/sub〉O were measured every 7 d when possible using a static chamber method from the 2013 rice season to the 2016 wheat season. Our results showed that the straw incorporation treatments significantly influenced the seasonal CH〈sub〉4〈/sub〉 and N〈sub〉2〈/sub〉O emissions and rice yield but had no influence on wheat yield. Straw incorporation significantly increased the annual topsoil SOC sequestration rate by 0.24–0.43 t C ha〈sup〉−1〈/sup〉 yr〈sup〉−1〈/sup〉 and the annual CH〈sub〉4〈/sub〉 and N〈sub〉2〈/sub〉O emissions by 44–138 kg CH〈sub〉4〈/sub〉-C ha〈sup〉−1〈/sup〉 yr〈sup〉−1〈/sup〉 and 0.68–1.49 kg N〈sub〉2〈/sub〉O-N ha〈sup〉−1〈/sup〉 yr〈sup〉−1〈/sup〉, respectively. Relative to the RS treatment, the WS and WSRS treatments significantly increased annual CH〈sub〉4〈/sub〉 emissions by 38% and 61%, respectively. Relative to the RS treatment, the WSRS treatment significantly increased the annual N〈sub〉2〈/sub〉O emissions, by 35%. The average annual yields were significantly higher in the WSRS (16.8 t ha〈sup〉−1〈/sup〉 yr〈sup〉−1〈/sup〉) and RS (16.7 t ha〈sup〉−1〈/sup〉 yr〈sup〉−1〈/sup〉) treatments than in the WS (15.7 t ha〈sup〉−1〈/sup〉 yr〈sup〉−1〈/sup〉) and control (15.2 t ha〈sup〉−1〈/sup〉 yr〈sup〉−1〈/sup〉) treatments. Across the three rotation cycles, the annual net global warming potential and greenhouse gas intensity were similar between the control and RS treatments but were significantly lower in these treatments than in the WSRS and WS treatments. These findings suggest that the RS treatment can simultaneously increase crop yields and environmental sustainability in rice–wheat cropping systems.〈/p〉〈/div〉

Description: 〈p〉Publication date: December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil and Tillage Research, Volume 195〈/p〉 〈p〉Author(s): Milson Evaldo Serafim, Walmes Marques Zeviani, Fábio Benedito Ono, Leonarda Grillo Neves, Bruno Montoani Silva, Rattan Lal〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The increasing demand of society for agricultural products and environmental services, charges agriculture a convergence between productivity gains and soil quality. In view of this, the establishment of boundary values ​​for productivity and for soil quality in areas of high productivity and under conservation management systems were the target of this study. The objective of this study was to obtain reference values ​​for the chemical, physical and biological properties of areas under no-till (NT) management in the southern region of the state of Mato Grosso, Cerrado region, Brazil. A total of 65 commercial soybean crop areas were sampled at the 0.0–0.10, 0.10–0.20 and 0.20–0.40 m layers. The productivity of the stands selected for the study was higher than the state average (3.32 Mg ha〈sup〉−1〈/sup〉) and the national average (3.29 Mg ha〈sup〉−1〈/sup〉). In 26 of these areas, which represented environments of high soybean yield, the 3-year average productivity in 2015, 2016 and 2017 was above 4.2 Mg ha〈sup〉−1〈/sup〉. The use of a quantitative regression analysis was an effective way to obtain the limits of the interval that is considered adequate to assure high productivities for each property. Among the 75 replicated variables obtained from 29 soil properties of three layers, 18 were significant for soybean yield. The soil properties that were significant in at least one of the layers were acid phosphatase, calcium, magnesium, potassium, the S index, the soil water retention curve (SWRC) inflection point, field capacity, pH (H〈sub〉2〈/sub〉O), the available water capacity, bulk density, particle density and base saturation. The reference values ​​of the soil properties that are suitable for productivity are also indicators of good soil quality. These results indicate a convergence between a high productive potential and good soil quality, which was explained by the impact of the NT system on soil quality in the studied areas.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 20 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Dendrochronologia〈/p〉 〈p〉Author(s): Feng Wang, Dominique Arseneault, Biao Pan, Qian Liao, Junji Sugiyama〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Although it has been widely recognized that tree-ring response to climate drivers may change over recent decades, often due to anthropogenic environment changes, there are fewer reports of such changes in earlier pre-warming periods. In this paper we report on the pre-1930 unstable relationship between climate and tree-ring width (TRW) of 〈em〉Pinus taiwanensis〈/em〉 Hayata in southeastern China based on reliable long-term temperature data. TRW of 〈em〉P. taiwanensis〈/em〉 is strongly controlled by temperatures in two seasons, previous spring to summer (March to August, mainly June to July) and previous winter to current spring (December to March). However, TRW are insensitive to previous spring to summer temperature between 1890 and 1930. Reduced summer temperature variability, changing regimes of spring-summer temperature and precipitation, and complicated tree physiological processes behind the complex growth-climate relationship are the more likely causes of this phenomenon. This study adds to the body of knowledge that lower climate sensitivity of tree rings is not specific to the most recent decades.〈/p〉〈/div〉

Description: 〈p〉Publication date: Available online 20 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Journal of Terramechanics〈/p〉 〈p〉Author(s): Rui He, Corina Sandu, Javier E. Osorio〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The parameterization of terramechanics model for the tire off-road traction dynamics modeling relies exclusively on the plate-sinkage test and shear test (not using a tire as the shear tool), according to the existing literature. However, the plate-soil interaction cannot be considered the same as the tire-soil interaction (Plackett, 1985). Part II of this paper investigates whether the tire-soil test can be used to parameterize terramechanics model. The parameterization of the modified Bekker’s model, the Magic Formula tire model, and a bulk density estimation model, using the data from the series of tire and soil tests presented in Part I of this paper (He et al., n.d.), is discussed in detail herein. The parameterization approach presented herein can be used to develop tire off-road dynamics models.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 21 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Biology and Biochemistry〈/p〉 〈p〉Author(s): Florentine Spaans, Tancredi Caruso, Edith Hammer, Ian Montgomery〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Hedgerows structure agricultural landscape worldwide but little is known on their soil communities. In the intensively managed agricultural landscapes of Ireland and the UK, hedgerows protect soil from degradation and are thought to provide a reservoir of soil biodiversity for the farmed fields. But hedgerows are currently threatened by emergent tree diseases spread with rising volumes of trade in plants. This study analysed the effect of the most dominant hedgerow tree species on the composition and diversity of soil communities, which we estimated with oribatid mites in the context of an imminent ash dieback outbreak in Northern Ireland. We hypothesised that the environmental heterogeneity created by different tree species and good tree health are beneficial to the abundance and diversity of these soil communities. We found that communities differ, both in terms of species composition and relative abundances, between different trees in the trimmed hedgerows, and between untrimmed and trimmed hedgerows. The presence of trees was associated with more variable species composition. The analysis of phospholipid fatty acids (PLFA) showed that pasture and adjacent hedgerows were dominated by bacteria but there was no clear relationship between bacterial biomass and oribatid abundance or richness. However, changes in bacterial PLFAs were correlated positively with changes in oribatid community composition. Soil under ash trees which were diseased supported a higher species richness and greater abundance of oribatids than healthy trees. We conclude that the presence of different tree species in hedgerows adds to the overall diversity of soil hedgerow communities and hypothesise that the structural heterogeneity created by tree canopy drives increased diversity. Ill health in ash trees is currently positively affecting oribatid communities, possibly due to the temporarily increase in organic matter in soil. The epidemic of ash dieback, however, is expected to kill and remove trees in the medium term and so reduce soil community diversity in the long term.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 279〈/p〉 〈p〉Author(s): Cicero Lima de Almeida, Thayslan Renato Anchiêta de Carvalho, José Carlos de Araújo〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Leaf area index (LAI) influences hydrological processes as both active and passive agents. In the Caatinga biome, little is known about LAI and its relationship with hydrological variables. Thus, the objective of this work was to measure LAI for a preserved arboreal-shrub vegetation and correlate it with hydrological variables (precipitation, evapotranspiration and soil moisture) and spectral (vegetation indices) in order to evaluate and to monitor their dynamics in time and space. The experiment was carried out in the Aiuaba Experimental Basin, considering three soil-vegetation associations and two periods (dry and rainy seasons) for three years (2014–2016). The results showed that LAI maximum is influenced by the type of soil-vegetation association and does not change over time. Among the hydrological variables, all had a significant correlation with LAI, but the best result was obtained using soil moisture. The best performance among the vegetation indexes for LAI estimation of the preserved Caatinga shrub-arboreal area was the Enhanced Vegetation Index (EVI), as shown by the analyses. The presence of clouds during the rainy season prevented a better evaluation of LAI with vegetation index. We concluded that the LAI of a preserved arboreal shrub area in Caatinga (3.5 ± 1.3 m〈sup〉2〈/sup〉 m〈sup〉−2〈/sup〉) can be monitored utilizing only precipitation, the precipitation-to-potential evapotranspiration ratio and soil moisture.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Forest Ecology and Management, Volume 451〈/p〉 〈p〉Author(s): Shawn P. Brown, Allison M. Veach, Jonathan L. Horton, Emerald Ford, Ari Jumpponen, Richard Baird〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Decades of fire suppression coupled with changing climatic conditions have increased the frequency and intensity of wildfires. The Southern Appalachia region of the United States is predicted to be particularly susceptible to climatic changes, with predicted increases in fire severity and occurrence. Following the record breaking fire season in 2016 in Southern Appalachia, we examined wildfire impacts on soil chemistry and below ground communities (fungi and bacteria – Illumina MiSeq) within two substrates (duff and soil) at two adjacent locations with similar plant communities (Great Smoky Mountains National Park – ‘Chimney Top 2’ Fire (GRSM) and Nantahala National Forest – ‘Cliffside’ Fire (NNF)) from replicate plots representing a range of fire severities (unburned, low severity, moderate severity, severe). Differing fire severities changed community composition, and fire severity played a stronger role in structuring bacterial communities than in structuring fungal communities. Further, fire impacts on soil communities and functional guilds responses were location- and substrate-specific with NNF responding more strongly to fire than GRSM. Additionally, using a novel analysis tool (Axis Weighted Ordination Distance – AWOrD), domain and location specific responses to wildfire severity are demonstrated. Taken together, our results suggest context-dependency in microbial responses to fire that must be accounted for to generate ecosystem-wide recovery predictions.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Forest Ecology and Management, Volume 451〈/p〉 〈p〉Author(s): Alissa J. Freeman, William M. Hammond, Justin R. Dee, Richard C. Cobb, Stephen M. Marek, Henry D. Adams〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Incidents of 〈em〉Quercus〈/em〉 decline have been driven by complicated interactions among factors, such as temperature, drought, pathogenic fungi, insect pests, and stand structure, which operate at multiple time scales. Past incidents of elevated tree mortality during drought in the upland forests of Oklahoma were associated with biotic factors; specifically, the infection of 〈em〉Quercus〈/em〉 species by canker-causing fungi in the genus 〈em〉Biscogniauxia〈/em〉. Biscogniauxia canker and dieback have been previously associated with water stress but little is known about the interactions between forest densification, prescribed fire, water stress, and canker incidence. We investigated the effects of prescribed fire and reduced basal area on Biscogniauxia canker incidence in 〈em〉Quercus〈/em〉 species at the Pushmataha Wildlife Management Area (PWMA) in southeastern Oklahoma. The PWMA is an ongoing forest management experiment established in 1984 with stands maintained to the present day with prescribed fire return intervals of 34+yr, 4-yr, and 1-yr. Through field surveys we found that the incidence of Biscogniauxia canker was lowest among units with a fire return interval of 1–4 years (p 〈 0.002). Additionally, greater canopy dieback was associated with greater frequency of stem cankers. Management of these forests reduces basal area, alters water stress, and may reduce pathogen incidence due to both greater host resilience and reduction of sporulation sources. To evaluate associations among these factors, we assessed Biscogniauxia canker incidence and leaf stable C isotope composition (δ〈sup〉13〈/sup〉C)—an indicator of stomatal closure from drought stress—from 〈em〉Quercus marilandica〈/em〉 (blackjack oak) and 〈em〉Quercus stellata〈/em〉 (post oak) trees in units experiencing 34+yr, 4-yr, and 1-yr fire return intervals. We found that leaf δ〈sup〉13〈/sup〉C was highest in units experiencing 4-yr and 1-yr fire return intervals, indicating that these trees more frequently had closed stomata, counter to our expectation that the reduced basal area associated with frequent fire would decrease δ〈sup〉13〈/sup〉C due to decreased water stress. Instead, our results suggest that trees in units experiencing reduced basal area encounter additional stressors (e.g., wind, vapor pressure deficit, and high soil evaporation) that lead to stomatal closure. Additionally, higher δ〈sup〉13〈/sup〉C in units receiving prescribed fire applications may be a response to frequent disturbance via direct effects of fire on tree water relations. Further investigation is needed to understand the interactions of fire regimes with water stress in these ecosystems. Although, we did not find a clear link to tree water status, basal area reduction decreased the incidence of Biscogniauxia canker, demonstrating that prescribed fire can be used to promote forest health.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Forest Ecology and Management, Volume 451〈/p〉 〈p〉Author(s): Débora Cristina Rother, Ana Paula Liboni, Luiz Fernando Silva Magnago, Anne Chao, Robin L. Chazdon, Ricardo Ribeiro Rodrigues〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Ecological restoration can re-establish plant species populations, enhance forested habitats extension, improve landscape connectivity, and enable biodiversity persistence within a landscape. However, the potential benefits of ecological restoration on beta diversity have never been explored. Here we use field data to investigate, for the first time, if restoration plantings enhance the taxonomic and functional plant beta diversity in a fragmented landscape of the threatened Atlantic forest. Woody species were evaluated for 320 plots established in 18 forest fragments and 14 restoration plantings within a sugarcane production landscape with low forest cover, in southeastern Brazil. Diversity metrics were assessed using the multiple incidence-data version of Hill numbers and were compared among three sets of study sites: fragments, restoration plantings and the two combined. Fragments showed higher levels of alpha diversity and proportional abundance of non-pioneer and animal-dispersed species than restoration plantings. Exotic, pioneer and non-zoochoric species were more abundant in restoration plantings, an expected result considering sites still be in the early or mid-successional stages of development. Taxonomic and functional beta diversity of trees was greatest when both areas were combined. For regenerating plants, however, beta diversity results varied according to species incidence-based frequencies. Although restoration plantings do not result in full recovery of alpha diversity, they can all together complement diversity of forest fragments at the landscape level. The findings indicate two key ecological implications for biodiversity conservation: the critical importance of forest fragments as biodiversity repositories and the positive effect of restoration efforts on landscape-scale diversity in degraded regions. These novel results highlight the importance of species selection for restoration initiatives toward species and functional attributes recognized as significantly reduced or locally rare. Overall, forest fragments and restoration plantings can act synergistically to promote recovery of plant diversity in heavily deforested agricultural landscapes.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 279〈/p〉 〈p〉Author(s): Maria Gabriela de Queiroz, Thieres George Freire da Silva, Sérgio Zolnier, Carlos André Alves de Souza, Luciana Sandra Bastos de Souza, Steidle Neto, Gherman Garcia Leal de Araújo, Williams Pinto Marques Ferreira〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The Caatinga Domain is exclusively Brazilian, covered by vegetation exhibiting a great diversity of species, which have morphological and physiological characteristics determined by environmental conditions. These attributes define quantity and quality litterfall deposition on the soil. The litterfall deposition seasonality was monitored a fragment of Caatinga vegetation, located in the semiarid region of Brazil, from 2016 to 2017. The decomposition rate, mean residence time for litterfall (50 and 95%), and the exportation of mineral nutrients via deciduous material were determined. Data from meteorological variables and litterfall were used in the elaboration of Pearson's correlation matrix, and multicollinearity, canonical and path analyzes. The Caatinga deposited on average 637 kg DM (dry mass) ha〈sup〉−1〈/sup〉 year〈sup〉−1〈/sup〉 litterfall, including 53% leaves, 26% twigs, 15% reproductive structures and 6% miscellanea, with deposition peaks between the months of March and July, with values above 57 kg MS ha〈sup〉−1〈/sup〉. Global solar radiation, vapor pressure deficit, soil heat flux, rainfall and normalized difference vegetation index are controlling factors the litterfall deposition. The decomposition rate of the litterfall was 0.33 kg DM ha〈sup〉−1〈/sup〉 year〈sup〉−1〈/sup〉, while the time required for the disappearance of 50% and 95% of the litterfall was respectively 2.1 and 9.1 years, and the exportation of nutrients was 13.59 kg ha〈sup〉−1〈/sup〉 year〈sup〉−1〈/sup〉. Litterfall deposition was determined by the environmental conditions and physiological responses of the vegetation, which are fundamental to maintaining the Caatinga Domain.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 279〈/p〉 〈p〉Author(s): M.J. Vergotti, M. Fernández-Martínez, S.C. Kefauver, I.A. Janssens, J. Peñuelas〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Some tree species have a highly variable year-to-year pattern of reproduction which has repercussions for the entire ecosystem. Links between meteorological variability, fruit production and crown cover, and trade-offs between reproduction and vegetative growth, remain elusive, despite a long history of research. We explored how meteorological conditions determined variations in fruit production and crown cover and how remotely sensed vegetation indices, such as the enhanced vegetation index (EVI), may be used to characterize the fluctuations in fruit production. We used data for fruit production from six European tree species (〈em〉Abies alba, Picea abies, Pseudotsuga menziesii, Fagus sylvatica, Quercus petraea〈/em〉 and 〈em〉Q. robur〈/em〉) growing in monospecific stands, EVI and seasonal meteorological variables (precipitation and temperature) for 2002–2010. Weather accounted for fruit production better than EVI. Deciduous trees were more responsive to weather than evergreens, most notably to different seasonal temperatures, which were positively correlated mainly with crown cover and fruit production in deciduous species. Our results also suggested different patterns of relationships between fruit production, crown cover and weather, indicating different strategies of resource management. These patterns indicated a possible internal trade-off in evergreens, with resources allocated to either growth or reproduction. In contrast, in deciduous species we found no evidence for such a trade-off between vegetative growth and reproduction.〈/p〉〈/div〉

Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Forest Ecology and Management, Volume 451〈/p〉 〈p〉Author(s): Lisa J. Samuelson, Tom A. Stokes, Michael R. Ramirez, Caren C. Mendonca〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Longleaf pine (〈em〉Pinus palustris〈/em〉 Mill.) forests are thought to be drought tolerant and if so, planting longleaf pine presents a forest management strategy for climate change adaptation in the southeastern United States (U.S.). To better understand how longleaf pine copes with drought, leaf water relations, sap flow, canopy stomatal conductance (G〈sub〉S〈/sub〉), and growth were studied over three growing seasons in response to ambient throughfall (ambient treatment) versus an approximate 40% reduction in throughfall (drought treatment) in a 13-year-old plantation. An exceptional drought occurred the first year of the study and decreased mean predawn (Ψ〈sub〉PD〈/sub〉) and midday (Ψ〈sub〉MD〈/sub〉) leaf water potential to −2.9 MPa and −3.6 MPa, respectively, and decreased average monthly midday Gs to near zero for at least one month in both treatments. Stomatal closure occurred at a Ψ〈sub〉MD〈/sub〉 of −3.0 MPa in both treatments. Leaf water potentials and transpiration recovered quickly following significant rain events that terminated the drought and mortality was similar among years and treatments (2.8%). Longleaf pine responded to drought treatment with greater stomatal control of plant water loss rather than adjustments in leaf area, the sapwood to leaf area ratio, or leaf water potential at the turgor loss point (Ψ〈sub〉TLP〈/sub〉). Annual transpiration per unit leaf area was reduced 16% by drought treatment, but greater stomatal control of water loss in response to drought treatment was associated with decreases in growth efficiency and volume, and no improvement in water use efficiency.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 1 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Geoderma, Volume 353〈/p〉 〈p〉Author(s): Cancan Zhao, Jie Zhao, Jianping Wu, Aimée T. Classen, Yanxia Li, Yiping Lou, Weixin Zhang, Xin Jing, Yuanhu Shao, Shenglei Fu〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Bamboos are widespread in the subtropics and tropics. They grow quickly, and are therefore important substitute for timber. Bamboo forest management and cultivation often include removing competitive trees; thus these shifts in forest composition should cascade to impact soil communities and the processes they mediate. Using a long-term (12 year) bamboo forest management study, we determined the impact of bamboo forest management on soil microbial and nematode community composition through time (2008–2010). Surprisingly, we found that conversion from a mixed and relatively diverse bamboo forest to a pure bamboo forest did not affect bamboo biomass. However, the soil fungal:bacterial ratio, nematode diversity index, and fungivores:bacterivores all declined within and across years. Taken together, our results suggest that conversion from mixed to pure bamboo forest can cause a switch from the fungal-based to the bacterial-based energy channel, i.e., accelerate the energy flow and reduce the stability of the soil ecosystem. The findings suggest that managing for a mixed bamboo forest may increase forest diversity and health overtime.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Mariana Maluli Marinho de Mello, Camila de Fátima Pereira de Faria, Fábio Sabbadin Zanuzzo, Elisabeth Criscuolo Urbinati〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In this study, we show that β-glucan can modulate cortisol release in fish. We simulated a common situation in aquaculture: the transport of fish followed by contact with an opportunistic pathogen and observed what effect glucan had on the immune and stress response in these conditions. Pacu (〈em〉Piaractus mesopotamicus〈/em〉) were fed with a diet containing β-glucan (0.1%) for 15 days prior to transport followed by an injection with heat-killed 〈em〉Aeromonas hydrophila.〈/em〉 We sampled fish before transport, at arrival and at 3 and 24 h after bacterial injection. β-Glucans are used in aquaculture and have a known immunostimulatory effect, which was observed in this study. The results showed that β-glucan modulated the plasma cortisol levels differently by increasing these levels up to 24 h after transport and preventing the increase caused by bacterial inoculum injection. In addition, β-glucan enhanced the activity of the complement system at 24 h and reduced the monocytes and lymphocytes number in peripheral blood at 3 and 24 h after bacterial inoculation. Our results suggest that β-glucan modulated a bidirectional interaction between the stress and the immune responses. The modulation of cortisol levels and the immunostimulation by β-glucan at different moments in our study suggest the compound has a protective effect by avoiding higher levels of the hormone and improving resistance against bacterial infection in pacu. These results add evidence to support the use of β-glucan as an immunomodulator in the aquaculture industry.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Min Sun Kim, Ki Hong Kim〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Although the type I interferon-mediated increase of Mx1 and ISG15 gene expression in Epithelioma papulosum cyprini (EPC) cells has been reported, the antiviral role of Mx1 and ISG15 in EPC cells has not been investigated. In this study, to know the anti-viral hemorrhagic septicemia virus (VHSV) role of Mx1 and ISG15 of EPC cells, either Mx1 or ISG15 gene was knocked-out using a CRISPR/Cas9 system, and the progression of cytopathic effects (CPE) and viral growth were analyzed. Mx1 gene and ISG15 gene knockout EPC cells were successfully produced via CRISPR/Cas9 coupled with a single-cell cloning. Through the sequence analysis, one clone showing two heterozygous indel patterns in Mx1 gene and a clone showing three heterozygous indel patterns in ISG15 gene were selected for further analyses. Mx1 knockout EPC cells did not show any differences in VHSV-mediated CPE progression, even when pre-treated with polyinosinic:polycytidylic acid (poly I:C), compared to control EPC cells. These results suggest that Mx1 in EPC cells may be unfunctional to cytoplasmic RNA viruses. In contrast to Mx1, ISG15 knockout cells showed clearly hampered anti-VHSV activity even when pre-treated with poly I:C, indicating that ISG15 plays an important role in type I interferon-mediated anti-viral activity in EPC cells, which allowed VHSV to replicate more efficiently in ISG15 knockout cells than Mx1 knockout and control cells.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 94〈/p〉 〈p〉Author(s): José Luis Sánchez-Salgado, Mohamed Alí Pereyra, Concepción Agundis, Montserrat Calzada-Ruiz, Erika Kantun-Briceño, Edgar Zenteno〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉In crustaceans, it has been suggested that specific protection against pathogens could be triggered by vaccines and biological response modifiers; although the specific mechanisms of this protection have not been clarified yet. In the crayfish 〈em〉Cherax quadricarinatus〈/em〉, a humoral lectin (CqL) binds its own granular hemocytes through a specific receptor (CqLR) and increases the production of reactive oxygen species (ROS). In the present study, we challenged 〈em〉in vivo〈/em〉 crayfishes with immunostimulants, β-glucan (200 μg/kg) or LPS (20 μg/kg), and identified the participation of cellular and humoral mechanisms. The stimulants generated a complex modification in the total hemocytes count (THC), as well as in the proportion of hemocyte subsets. At 2 h after the challenge, the largest value in THC was observed in either challenged crayfishes. Furthermore, at the same time, hyaline hemocytes were the most abundant subset in the hemolymph; after 6 h, granular hemocytes (GH) were the most abundant hemocyte subset. It has been observed that a specific subset of GH possesses a CqLR that has been related to ROS production. After 2 and 6 h of the β-glucan challenge, a significant increase in CqLR expression was observed in the three circulating hemocyte subsets; also, an increased expression of CqL was detected in a granular hemocytes sub-population. After 2 and 6 h of stimulation, the specific activity of the serum lectin challenged with β-glucan was 250% and 160% higher than in the LPS-treated-group, respectively (〈em〉P〈/em〉 〈 0.05). Hemocytes from challenged crayfishes were stimulated 〈em〉ex vivo〈/em〉 with CqL, ROS production was 180% higher in hemocytes treated with β-glucan + CqL than in hemocytes treated with LPS + CqL (〈em〉P〈/em〉 〈 0.05). The results evidence the effectivity of immune stimulators to activate specific crayfish defense mechanisms, the participation of CqL and its receptor (CqLR) could play an important role in the regulation of immune cellular functions, like ROS production, in 〈em〉Cherax quadricarinatus〈/em〉.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: Available online 22 August 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Biology and Biochemistry〈/p〉 〈p〉Author(s): Thea Whitman, Ellen Whitman, Jamie Woolet, Mike D. Flannigan, Dan K. Thompson, Marc-André Parisien〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Global fire regimes are changing, with increases in wildfire frequency and severity expected for many North American forests over the next 100 years. Fires can result in dramatic changes to carbon (C) stocks and can restructure plant and microbial communities, with long-lasting effects on ecosystem functions. We investigated wildfire effects on soil microbial communities (bacteria and fungi) in an extreme fire season in the northwestern Canadian boreal forest, using field surveys, remote sensing, and high-throughput amplicon sequencing in upland and wetland sites. We hypothesized that vegetation community and soil pH would be the most important determinants of microbial community composition, while the effect of fire might not be significant, and found that fire occurrence, along with vegetation community, moisture regime, pH, total carbon, and soil texture are all significant predictors of soil microbial community composition. Burned communities become increasingly dissimilar to unburned communities with increasingly severe burns, and the burn severity index (an index of the fractional area of consumed organic soils and exposed mineral soils) best predicted total bacterial community composition, while whether a site was burned or not was the best predictor for fungi. Globally abundant taxa were identified as significant positive fire responders in this system, including the bacteria 〈em〉Massilia〈/em〉 sp. (64 × more abundant with fire) and 〈em〉Arthrobacter〈/em〉 sp. (35 × ), and the fungi 〈em〉Penicillium〈/em〉 sp. (22 × ) and 〈em〉Fusicladium〈/em〉 sp. (12 × ). Bacterial and fungal co-occurrence network modules were characterized by fire responsiveness as well as pH and moisture regime. Building on the efforts of previous studies, our results consider a particularly wide range of soils, vegetation, and burn severities, and we identify specific fire-responsive microbial taxa and suggest that accounting for burn severity improves our understanding of microbial response to fires.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil Biology and Biochemistry, Volume 137〈/p〉 〈p〉Author(s): Chengjiao Duan, Bahar S. Razavi, Guoting Shen, Yongxing Cui, Wenliang Ju, Shiqing Li, Linchuan Fang〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Legume–rhizobium symbiosis plays an important role in agriculture and ecological restoration. However, the regulatory mechanisms of rhizobium in alleviating heavy metal stress through the biochemical response of plant-soil system is limited. In this study, alfalfa was inoculated with a copper (Cu)-resistant rhizobium, and its effect on plant growth and the spatial distribution of phosphatase in the rhizosphere under Cu stress was assessed. Our results showed that rhizobium inoculation alleviated Cu-induced growth inhibition, and increased the nitrogen and phosphorus content in alfalfa tissues. Moreover, inoculated plants had a higher Cu uptake than non-inoculated plants, with a much higher increase in the roots than in the shoots; thus, inoculation with rhizobium was shown to decrease the transfer coefficient and promote Cu phytostabilization. The zymograms illustrated that the distribution of phosphatase activities was associated with the presence of roots. Compared with the non-inoculated treatment, the rhizobium inoculation increased the hotspot areas of phosphatase by 26.1% and 39.3% at the Cu 0 and Cu 800 treatments, respectively. In addition, the available phosphorus in the soil showed negative correlations with soil phosphatase activity (〈em〉p〈/em〉 〈 0.05). The model of partial least squares path modelling (PLS-PM) indicated that soil Cu content directly influenced the hotspot areas of phosphatase activities in the rhizosphere and explained most (86%) of the variation. Thus, the enzymatic hotspots were concluded to mainly be affected by the Cu content of soil, and the phosphatase activities in the rhizosphere were mainly regulated by the ratio of nitrogen to phosphorus. These findings provide a basis for the spatio-temporal dynamics of biogeochemical reactions in the rhizosphere of polluted soils.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S003807171930238X-fx1.jpg" width="322" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Nikolai Mugue, Nadezhda Terekhanova, Sergey Afanasyev, Aleksei Krasnov〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Sturgeons represent a substantial scientific interest due to their high economic value, endangered status and also as the most primitive group of ray-finned fishes. Rapid progress in knowledge of sturgeon immunity was achieved recently with use of RNA sequencing. We report transcriptome sequencing of gill, head kidney, and spleen of bester sturgeon (a hybrid of beluga 〈em〉Huso huso〈/em〉 and sterlet 〈em〉Acipen〈/em〉s〈em〉er ruthenus〈/em〉) injected with synthetic double-stranded RNA (polyI:C). The composition of transcriptome and responses to treatment were examined in the context of comparative genomics with focus on immune genes. Sturgeon transcripts matched to 21.5 k different proteins (blastx). With reference to Atlantic salmon, the functional groups and pathways of the immune system were uniformly represented: at average 36.5 ± 0.8% genes were found. Immune genes comprise a significant fraction of transcriptome. Among twenty genes with highest transcription levels, five are specialized immune genes and two encode heme and iron binding proteins (〈em〉serotransferrin〈/em〉 and 〈em〉hemopexin〈/em〉) also known as acute phase proteins. Challenge induced multiple functional groups including apoptosis, cell cycle and a number of metabolic pathways. Treatment stimulated innate antiviral immunity, which is well conserved between sturgeon and salmon, the most responsive genes were 〈em〉mx, rsad2 (viperin)〈/em〉, 〈em〉interferon induced protein 44〈/em〉 and 〈em〉protein with tetratricopeptide repeats 5〈/em〉, 〈em〉cd87〈/em〉 and 〈em〉receptor transporting protein 3〈/em〉. Results added to knowledge of immune phylogeny. Gain and loss of genes was assessed by comparison with genomes from different phylogenetic groups. Among differentially expressed genes, percentage of acquired and lost genes was much lower in comparison with genes present in all vertebrates. Innate antiviral immunity was subject to the greatest changes in evolution of jawed vertebrates. A significant fraction of genes (15%) was lost in mammals and only half of genes is annotated in public databases as involved in antiviral responses. Change of function may have an important role in evolution of immunity together with gain and loss of genes.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Malene Soleng, Lill-Heidi Johansen, Hanne Johnsen, Gunhild S. Johansson, Mette W. Breiland, Lisbeth Rørmark, Karin Pittman, Lars-Flemming Pedersen, Carlo C. Lazado〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Peracetic acid (PAA), a strong organic peroxide, is considered a relatively sustainable disinfectant in aquaculture because of its broad effectivity against many pathogens at low concentrations and because it degrades spontaneously to harmless residues. The impacts of PAA on fish health must be determined before its use as either a routine disinfectant or chemotherapeutant. Here we investigated the systemic and mucosal stress responses of Atlantic salmon (〈em〉Salmo salar〈/em〉) to PAA. In experiment 1, salmon were exposed to different nominal concentrations (0, 0.6, and 2.4 ppm) of PAA for 5 min, followed by a re-exposure to the same concentrations for 30 min 2 weeks later. Sampling was performed before exposure to PAA and at 2 h, 48 h, and 2 w after exposures. In experiment 2, fish were subjected to crowding stress prior to PAA exposure at 4.8 ppm for 30 min. The fish were sampled before exposure and 1 h, 4 h, and 2 w after. The two trials were performed in a recirculation system. Both systemic (i.e., plasma cortisol, glucose, lactate, total antioxidant capacity) and mucosal (i.e., expression of antioxidant coding genes in the skin and gills) stress indicators were affected by the treatments at varying levels, and it was apparent that the fish were able to mount a robust response to the physiological demands of PAA exposure. The cortisol levels increased in the early hours after exposure and returned to basal level afterwards. Prior exposure history to PAA did not markedly affect the levels of plasma lactate and glucose when fish were re-exposed to PAA. Crowding stress before PAA treatment, however, did alter some of the stress indicators (i.e., lactate, glucose and expression of antioxidant genes in the gills), suggesting that stress history serves as both a confounding and compounding factor on how stress responses to PAA are mobilised. Nonetheless, the changes were not substantial. Gene expression profile analyses revealed that the antioxidant system was more responsive to PAA in the gills than in the skin. The increased antioxidant capacity in the plasma, particularly at 2.4 ppm and higher, indicates that antioxidants were produced to neutralise the internal redox imbalance resulting from PAA exposure. In conclusion, the results show that salmon were able to mount a robust adaptive response to different PAA doses and exposure times, and a combined exposure to stress and PAA. These results underscore the potential of PAA as a chemotherapeutant for salmon at PAA concentrations commonly applied to control parasitic infestations.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Zhiwei Cao, Sijia Liu, Hao Nan, Kaixia Zhao, Xiaodong Xu, Gaoxue Wang, Hong Ji, Hongying Chen〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Cyprinid herpesvirus 2 (CyHV-2) is the causative pathogen of herpesviral haematopoietic necrosis disease, which has caused huge economic losses to aquaculture industry in China. In this study, nine truncated CyHV-2 membrane glycoproteins (ORF25, ORF25C, ORF25D, ORF30, ORF124, ORF131, ORF136, ORF142A, ORF146) and a GFP reporter protein were respectively expressed using baculovirus surface displaying system. Western blot showed that the proteins were successfully packaged in the recombinant virus particles. In baculovirus transduced gibel carp kidney cells, the target proteins were expressed and displayed on the fish cell surface. Healthy gibel carp were immunized by immersion with the recombinant baculoviruses and the fish treated with phosphate-buffered saline (PBS) were served as mock group. The expression of 〈em〉interleukin-11〈/em〉 (〈em〉IL-11〈/em〉), 〈em〉interferon α〈/em〉 (〈em〉IFNα〈/em〉) and a complement component gene 〈em〉C3〈/em〉 were significantly up-regulated in most experimental groups, and 〈em〉interferon γ〈/em〉 (〈em〉IFNγ〈/em〉) expression in some groups were also induced after immunization. Subsequently, the immunized gibel carp were challenged by intraperitoneal injection of CyHV-2 virus. All the immunized groups exhibited reduced mortality after CyHV-2 challenge. In the groups immunized with baculoviruses displaying and expressing ORF25, ORF25C and ORF146, the relative percentage survival values reached 83.3%, 87.5% and 70.8%, respectively. Our data suggested that baculovirus-displayed ORF25, ORF25C and ORF146 could be potential vaccine candidates for the prevention of CyHV-2 infection in gibel carp.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil and Tillage Research, Volume 195〈/p〉 〈p〉Author(s): Hanxi Wang, Jianling Xu, Xuejun Liu, Di Zhang, Longwei Li, Wei Li, Lianxi Sheng〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Long-term fertilization causes declines in soil quality and crop yield, hindering current agricultural development. This paper is about the effect of long-term fertilization (20 years) in Hunan’s Qiyang County. It was found that chemical nitrogen, phosphorus, and potassium (NPK) fertilizer lowered soil pH by an annual average of 0.07, while organic fertilizer increased soil pH by about 0.04. Furthermore, organic fertilizer and chemical fertilizer both increased total soil organic carbon (SOC). Long-term chemical NPK and organic fertilizer increased straw and grain yield of wheat and maize to a greater extent than did other fertilization methods. Thus, our results suggest that mixing organic fertilizer with chemical NPK fertilizer should prevent soil acidification and elevate crop yield.〈/p〉〈/div〉

Description: 〈p〉Publication date: December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Soil and Tillage Research, Volume 195〈/p〉 〈p〉Author(s): Iris Vogeler, Rogerio Cichota, Ingrid K. Thomsen, Sander Bruun, Lars Stoumann Jensen, Johannes W.M. Pullens〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Determining the nitrogen (N) release from catch crop residues is important for N management in arable farming systems. The use of catch crops and subsequent incorporation of its residues represents a nutrient provision for the following crop and has the potential of reducing N leaching. To investigate whether the Agricultural Production Simulator (APSIM) can be used to predict the N release from 〈em〉Brassica〈/em〉 catch crop residues with different carbon to nitrogen ratios (C:N) under different temperatures the model was set-up using three different approaches: (i) the generic approach, in which the residue is distributed to the various carbon pools with default APSIM parameters (Gen), (ii) the generic approach but with partitioning of the various pools based on the biochemical composition (Gen-BC), and (iii) the inclusion of an additional carbon pool in which mineralisation is based on first order decay and the C:N of the crop residue, termed simple mineralisation model (SMM). The SMM was parameterized based on results from various previous incubation studies. APSIM was then used to predict N release through mineralisation from these experiments. The simulations indicate that the generic approach in APSIM greatly underestimates the amount of N released from the cover crop residues, especially at low temperatures; the model efficiency (based on the Nash Sutcliffe efficiency score) was negative for the incubation study done at 2 °C. APSIM linked with the SMM shows a substantially higher prediction accuracy. The Gen-BC, which could only be done for one of the incubation experiments, had a higher prediction accuracy than the generic approach, but was not as good as the SMM. This indicates that, for accurate predictions of N mineralisation from 〈em〉Brassica〈/em〉 catch crop residues, the generic approach with default partitioning needs to be modified, either by assigning various carbon pools based on the biochemical composition or by including an additional carbon pool.〈/p〉〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Armando Vega-López, Nataraj S. Pagadala, Brenda P. López-Tapia, Ruth L. Madera-Sandoval, Erika Rosales-Cruz, Minerva Nájera-Martínez, Elba Reyes-Maldonado〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉The signaling mediated by small non-proteinogenic molecules, which probably have the capacity to serve as a bridge amongst complex systems is one of the most exiting challenges for the study. In the current report, stem cells differentiation of the immune system in Nile tilapia treated with sub-basal doses of GABA evaluated as c-kit〈sup〉+〈/sup〉 and Sca-1〈sup〉+〈/sup〉 cells disappearance on pronephros, thymus, spleen and peripheral blood mononuclear cells by flow cytometry was assessed. Explanation of biological response was performed by molecular docking approach and multiparametric analysis. Stem cell differentiation depends on a delicate balance of negative and positive interactions of this neurotransmitter with receptors and transcription factors involved in this process. This in turn depends on the type of interaction with hematopoietic niche to differentiate into primordial, early or late hematopoiesis as well as from the dose delivery. In fish treated with the low doses of GABA (0.1% over basal value) primordial hematopoiesis is regulated by interaction of glutamate (Glu) with the Ly-6 antigen. Early hematopoiesis was influenced by the bond of GABA near or adjacent to turns of FLTR3-Ig-IV domain. During late hematopoiesis, negative regulation by structural modifications on PU.1/IRF-4 complex, IL-7Rα and GM-CSFR mainly prevails. Results of molecular docking were in agreement with the percentages of the main blood cells lineages estimated in pronephros by flow cytometry. Current study provides the first evidences about the role of inhibitory and excitatory neurotransmitters such as GABA and Glu, respectively with the most transcriptional factors and receptors involved on hematopoiesis in adult Nile tilapia.〈/p〉〈/div〉 〈/div〉 〈h5〉Graphical abstract〈/h5〉 〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1050464819308320-fx1.jpg" width="266" alt="Image 1" title="Image 1"〉〈/figure〉〈/p〉〈/div〉

Description: 〈p〉Publication date: October 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Fish & Shellfish Immunology, Volume 93〈/p〉 〈p〉Author(s): Xianyun Ren, Yunbin Zhang, Ping Liu, Jian Li〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉This study aimed to use isobaric tags (IBTs) to investigate the immune response of the hepatopancreas of 〈em〉Marsupenaeus japonicas〈/em〉 infected with 〈em〉Vibrio parahaemolyticus〈/em〉 or white spot syndrome virus (WSSV). Liquid chromatography-tandem mass spectrometry and protein sequencing identified 1005 proteins. Among them, 109 proteins were upregulated and 94 were downregulated after 〈em〉V. parahaemolyticus〈/em〉 infection. After WSSV infection, 130 proteins were identified as differentially abundant, including 88 that were upregulated and 42 were downregulated. Fifty-four proteins were identified as differentially abundant after both 〈em〉V. parahaemolyticus〈/em〉 and WSSV infection. A number of proteins related to cytoskeletal processes, including actin and myosin, and apoptosis-related proteins were upregulated in shrimp after 〈em〉V. parahaemolyticus〈/em〉 and WSSV infection, indicating that phagocytosis and apoptosis may be involved in the response to in 〈em〉V. parahaemolyticus〈/em〉 or WSSV infection. Quantitative real-time PCR was carried out to verify the reliability of the proteomic data. These data provide a basis to characterize the immunity-related processes of shrimp in response to infection with WSSV or 〈em〉V. parahaemolyticus〈/em〉.〈/p〉〈/div〉 〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 278〈/p〉 〈p〉Author(s): Yuki Nakano, Naoto Iwasaki〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Sugars accumulated in fruits are synthesized in leaves and translocated into the fruits. Quantitative measurement of phloem sap flow would enhance our understanding of the phenomenon and would facilitate efforts to ensure the production of high-quality fruits. The influence of girdling, which cuts off phloem, on sap flow rate determined using the heat balance method, was investigated in citrus. The present study aimed to measure the flow rates in phloem and xylem sap separately and to investigate the effect of gauge temperature on gauge output accuracy. When the gauge temperature was kept constant, the flow rate was consistent with the amount of water transpired from the branch. Immediately after girdling, the sap flow rate increased in a non-bearing branch, but decreased in a bearing branch. We conclude that the phloem sap flowed basipetally in the non-bearing branch and acropetally toward the fruits in the bearing branch. Regression lines for the sap flow before and after girdling were almost parallel, and the difference in the intercept of the two regression lines can be regarded as the flow rate change caused by girdling. Our results indicate that it is possible to determine separate flow rates for phloem and xylem sap by combining the heat balance method with girdling.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 278〈/p〉 〈p〉Author(s): A.B. Ariza-Villaverde, P. Pavón-Domínguez, R. Carmona-Cabezas, E. Gutiérrez de Ravé, F.J. Jiménez-Hornero〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉Previous works have analysed the relationship existing between reference evapotranspiration (〈em〉ET〈sub〉0〈/sub〉〈/em〉) and other climatic variables under a one-at-a-time perturbation condition. However, due to the physical relationships between these climatic variables is advisable to study their joint influence on 〈em〉ET〈sub〉0〈/sub〉〈/em〉. The box-counting joint multifractal algorithm describes the relations between variables using relevant information extracted from the data singularities. This work investigated the use of this algorithm to describe the simultaneous behaviour of 〈em〉ET〈sub〉0〈/sub〉〈/em〉, calculated by means of Penman–Monteith (PM) equation, and the two main climatic variables, relative humidity (〈em〉RH〈/em〉) and air temperature (〈em〉T〈/em〉), influencing on it in the middle zone of the Guadalquivir river valley, Andalusia, southern Spain. The studied cases were grouped according to the fractal dimension values, obtained from the global multifractal analysis, which were related to their probability of occurrence. The most likely cases were linked to smooth behaviour and weak dependence between variables, both circumstances were detected in the local multifractal analysis. For these cases, the rest of Penman Monteith (PM) equation variables, neither the 〈em〉T〈/em〉 nor the 〈em〉RH〈/em〉, seemed to influence on 〈em〉ET〈sub〉0〈/sub〉〈/em〉 determination, especially when low 〈em〉T〈/em〉 values were involved. By contrast, the least frequent cases were those with variables showing high fluctuations and strong relationship between them. In these situations, when 〈em〉T〈/em〉 is low, the 〈em〉ET〈sub〉0〈/sub〉〈/em〉 is affected by the rest of PM equation variables. This fact confirmed 〈em〉T〈/em〉 as main driver of 〈em〉ET〈sub〉0〈/sub〉〈/em〉 because the higher 〈em〉T〈/em〉 values the lesser influence of other climate variables on 〈em〉ET〈sub〉0〈/sub〉〈/em〉. This condition could not be extended to 〈em〉RH〈/em〉 because the variability in 〈em〉ET〈sub〉0〈/sub〉〈/em〉 singularities was not significantly influenced by low or high values of this variable. These results show that the joint multifractal analysis can be regarded as a suitable tool for describing the complex relationship between 〈em〉ET〈sub〉0〈/sub〉〈/em〉, 〈em〉T〈/em〉 and 〈em〉RH〈/em〉, providing additional information to that derived from descriptive statistics.〈/p〉 〈p〉Although, joint multifractal analysis shows some limitations when it is applied to large number of variables, the results reported are promising and suggest the convenience of exploring the relationships between 〈em〉ET〈sub〉0〈/sub〉〈/em〉 and other climatic variables not considered here with this framework such as wind speed and net radiation.〈/p〉 〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 279〈/p〉 〈p〉Author(s): Xingbang Hu, Huazhong Ren, Kevin Tansey, Yitong Zheng, Darren Ghent, Xufang Liu, Lei Yan〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Agricultural drought is one of most damaging agricultural hazards worldwide that can bring significant agricultural losses and water scarcity. The use of satellite images for monitoring agricultural drought has received increasing research attention and has also been applied at both the regional and global scales. In this paper, the land surface temperature (LST) and radiance products of the new Sentinel-3A SLSTR (sea and land surface temperature radiometer) launched by European Space Agency (ESA) are used for the first time for estimating the vegetation temperature condition index (VTCI), which in turn is used for monitoring agricultural drought in the Hetao Plain of Inner Mongolia, China. This paper initially analyzes the correlation between LST and normalized difference vegetation index (NDVI) by using time series time MODIS LST and NDVI products under different vegetation growth conditions. The findings reveal that VTCI can only be used in warm seasons (late spring and summer periods) when negative correlations between LST and NDVI are observed. Therefore, VTCI images are captured in the study area between July and August 2017 by using Sentinel-3A SLSTR LST and NDVI and are utilized for drought investigation. These images reveal that the average VTCI of the cultivated land pixels in the study area has increased from 0.4511 on July 28 to 0.5229 on August 12 before declining to 0.4710 on August 18 due to the rainfall in the first period, thereby indicating that VTCI has a timely response to rainfall. Meanwhile, cross-comparison of VTCI values from Sentinel-3A SLSTR shows high consistency in terms of spatial distribution with that estimated from EOS MODIS products. The difference between these indices ranged from −0.1 to 0.1 for most points, especially in the cultivated land cover. Overall, the findings support the use of the LST and NDVI products of Sentinel-3A SLSTR in monitoring agricultural drought.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 278〈/p〉 〈p〉Author(s): Geoffrey G. Parker, David R. Fitzjarrald, Irene Cibelle Gonçalves Sampaio〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉 〈p〉We studied the interplay of atmospheric and canopy structure factors driving the canopy light environment (Photosynthetic Photon Flux Density, PPFD) in primary moist tropical forest in the Tapajós National Forest, Brazil. We quantified the temporal and spatial length scales that characterize intact rain forest inhomogeneities, asking: Are seasonal changes in the canopy radiation balance evident at these scales? We sought to describe the components of intensity, duration and spatial variation of within-canopy PPFD in light of these inhomogeneities. Do fluctuating atmospheric conditions, especially the presence of clouds and precipitation, affect the radiative inputs at both the canopy top and the forest floor?〈/p〉 〈p〉We examined the characteristic scales of heterogeneity in the vertical and the horizontal using a two-part approach. For radiation we combined long-term continuous high-frequency measurements of down- and up-welling short-wave and visible wavebands above the canopy with similarly frequent observations from a dense sensor network at forest floor. Vertical variations in canopy structure, obtained with a ground-based LIDAR, similarly combined intensive observations at the sensor network with occasional large-scale transects along the forest floor. Close similarities in both radiation and canopy structure at both scales support the representativeness of local observations of the wider area.〈/p〉 〈p〉A composite broadband measure similar to the Normalized Difference Vegetation Index (denoted cbNDVI) was constructed from above-canopy observations to compare with reports of remotely sensed canopy reflectivity at this site. We estimated the canopy Leaf Area Index (LAI) by combining observations of the variation in understory transmittance by solar elevation with a commonly-used algorithm. We obtained the conventional whole-canopy extinction coefficient, by applying the Beer-Lambert law.〈/p〉 〈p〉Over the course of a year this forest receives 11,795 mol m〈sup〉−2〈/sup〉, only 62% of potential clear-day PPFD – atmospheric transmissivity is reduced by clouds, precipitation, smoke and haze. Very little PAR (≈ 2%) is reflected from the canopy and only 5.7% penetrates to 1 m above the forest floor - overall 92% of PAR is absorbed by the canopy. All radiation balance components closely tracked the dynamics of incoming light, showing little seasonal variation.〈/p〉 〈p〉Understory light observations across the 7.5–28.5 m spanning the understory array sensors showed essentially constant correlation between sensor pairs over time. There was a high degree of local persistence in the understory spatial pattern that varied slowly and directionally with the changing geometry of the sun and canopy structure. Over larger distances (to 1000 m), the patterns of spatial autocorrelation of understory PPFD and outer canopy structure were remarkably similar in shape, both declining rapidly to a more-or-less constant level around 15–20 m, a scale consistent with the dimensions of outer canopy crowns.〈/p〉 〈p〉The vertical pattern of transmission and absorption was estimated by combining understory transmittance with the distribution of canopy surface area obtained from the ground-based LIDAR system. It showed the maximum absorption relatively low in the canopy (8–19 m above ground). Although rather tall (canopy height is at 41.5 m), the extremely elaborate outer surface of the forest suggests the layers highest above ground are of little consequence to the PAR absorption budget.〈/p〉 〈p〉The cbNDVI measure exhibited seasonal variation consistent with other reports (somewhat higher in the wet season) but in contrast to a recent argument that the forest ‘greens up’ during the early dry season. However, except for the variations caused by the angle and intensity of incoming light modulated by atmospheric effects, there was little seasonality in the forest light environment at km67, including: canopy reflectances in several wavebands, all PPFD radiation budget components, the estimated LAI and mid-day PAR extinction coefficient and the length scales of understory PPFD. Canopy transmission was somewhat greater (6.4%) under diffuse skies compared to the least diffuse conditions (6.0%), and slightly more PPFD was absorbed under diffuse (92.7%) versus the least diffuse conditions (92.3%), but was not a significant contribution to the budget.〈/p〉 〈p〉The large diurnal variations in the extinction coefficient seriously affects its utility as a descriptor of canopy radiative properties. We propose an alternative approach for transmitted light: the canopy behaves as: 1.) a constant fraction filter under diffuse conditions, combined with 2.) a variable filter depending on solar elevation for sunfleck conditions. These regimes may be described with simple parameters each having mechanistic relations to canopy structure. In summary, we demonstrate that obtaining the radiation signal at forest floor at high data rate for long periods exploits seasonal sun angle changes to probe canopy structure. Combined with occasional long transect information, temporal and vertical sampling spatially allow improved definition of characteristic scales to describe both the understory light environment and canopy structure.〈/p〉 〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 278〈/p〉 〈p〉Author(s): Alireza Ghaemi, Mohammad Rezaie-Balf, Jan Adamowski, Ozgur Kisi, John Quilty〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Accurate pan evaporation (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si4.gif" overflow="scroll"〉〈msub〉〈mi〉E〈/mi〉〈mrow〉〈mi〉p〈/mi〉〈mi〉a〈/mi〉〈mi〉n〈/mi〉〈/mrow〉〈/msub〉〈/math〉) prediction is a critical issue in water resources management, particularly when designing and managing rural water resource systems, and when assessing water utilization and demand. In this study, Multivariate Adaptive Regression Spline (MARS) and M5 Model Tree (MT) models were coupled with a maximum overlap discrete wavelet transform (MODWT) to create 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si5.gif" overflow="scroll"〉〈msup〉〈mrow〉〈mtext〉M〈/mtext〉〈mtext〉A〈/mtext〉〈mtext〉R〈/mtext〉〈mtext〉S〈/mtext〉〈/mrow〉〈mrow〉〈mtext〉M〈/mtext〉〈mtext〉O〈/mtext〉〈mtext〉D〈/mtext〉〈mtext〉W〈/mtext〉〈mtext〉T〈/mtext〉〈/mrow〉〈/msup〉〈/math〉 and 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si6.gif" overflow="scroll"〉〈msup〉〈mrow〉〈mtext〉M〈/mtext〉〈mtext〉T〈/mtext〉〈/mrow〉〈mrow〉〈mtext〉M〈/mtext〉〈mtext〉O〈/mtext〉〈mtext〉D〈/mtext〉〈mtext〉W〈/mtext〉〈mtext〉T〈/mtext〉〈/mrow〉〈/msup〉〈/math〉 models for the prediction of monthly pan evaporation for Turkey’s Siirt and Diyarbakir meteorological stations. The performance of the standalone MARS and MT models was compared to the corresponding MODWT-based hybrid models. Furthermore, the developed hybrid models were combined with (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si4.gif" overflow="scroll"〉〈msub〉〈mi〉E〈/mi〉〈mrow〉〈mi〉p〈/mi〉〈mi〉a〈/mi〉〈mi〉n〈/mi〉〈/mrow〉〈/msub〉〈/math〉) Mallow’s coefficient (〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si7.gif" overflow="scroll"〉〈msub〉〈mi〉C〈/mi〉〈mi〉p〈/mi〉〈/msub〉〈/math〉) to minimize the number of predictor variables needed to predict monthly 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"〉〈msub〉〈mi〉E〈/mi〉〈mrow〉〈mtext〉p〈/mtext〉〈mtext〉a〈/mtext〉〈mtext〉n〈/mtext〉〈/mrow〉〈/msub〉〈/math〉. The models used preprocessed input data, including temperature (〈em〉T〈/em〉), wind speed (〈em〉W〈/em〉), relative humidity (〈em〉RH〈/em〉), and solar radiation (〈em〉SR〈/em〉). The performance of each approach was evaluated using standard statistical measures (〈em〉i.e〈/em〉., correlation coefficient (〈em〉R〈/em〉), root mean square error (〈em〉RMSE〈/em〉), Nash-Sutcliffe efficiency (〈em〉NSE〈/em〉) and mean absolute error (〈em〉MAE〈/em〉)). The results showed that the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si8.gif" overflow="scroll"〉〈msubsup〉〈mrow〉〈mtext〉M〈/mtext〉〈mtext〉A〈/mtext〉〈mtext〉R〈/mtext〉〈mtext〉S〈/mtext〉〈/mrow〉〈mrow〉〈msub〉〈mtext〉C〈/mtext〉〈mtext〉p〈/mtext〉〈/msub〉〈/mrow〉〈mrow〉〈mtext〉M〈/mtext〉〈mtext〉O〈/mtext〉〈mtext〉D〈/mtext〉〈mtext〉W〈/mtext〉〈mtext〉T〈/mtext〉〈/mrow〉〈/msubsup〉〈mtext〉 〈/mtext〉〈/math〉model improved the MARS accuracy with respect to lower percentages of 〈em〉RMSE〈/em〉 (29.46%) and 〈em〉MAE〈/em〉 (24.53%) in the validation phase for the Siirt station. In case of the Diyarbakir station, the 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si9.gif" overflow="scroll"〉〈msubsup〉〈mrow〉〈mtext〉M〈/mtext〉〈mtext〉A〈/mtext〉〈mtext〉R〈/mtext〉〈mtext〉S〈/mtext〉〈/mrow〉〈mrow〉〈msub〉〈mtext〉C〈/mtext〉〈mtext〉p〈/mtext〉〈/msub〉〈/mrow〉〈mrow〉〈mtext〉M〈/mtext〉〈mtext〉O〈/mtext〉〈mtext〉D〈/mtext〉〈mtext〉W〈/mtext〉〈mtext〉T〈/mtext〉〈/mrow〉〈/msubsup〉〈/math〉 improvements decreased the 〈em〉RMSE〈/em〉 (17.91%) and 〈em〉MAE〈/em〉 (16.49%) values in comparison to standalone MARS model. The overall results indicated that the use of both MODWT and 〈math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si7.gif" overflow="scroll"〉〈msub〉〈mi〉C〈/mi〉〈mi〉p〈/mi〉〈/msub〉〈/math〉 as pre-processing techniques improves prediction accuracy, and thus, they are both recommended for use in further studies.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 278〈/p〉 〈p〉Author(s): Marcin Zadworny, Andrzej M. Jagodziński, Piotr Łakomy, Joanna Mucha, Jacek Oleksyn, Jesús Rodríguez-Calcerrada, Krzysztof Ufnalski〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Oak trees (〈em〉Quercus〈/em〉 spp.) develop a taproot system which extends several meters deep and enables them to survive periods of water deficit that occur during their long lifespan. Regeneration forestry practices disturb the natural development and proportion of oak root systems by repeated undercutting of the taproots of seedlings in nurseries, or the repeated cutting of stems in coppice systems. Thus, regeneration practices may affect tree growth and susceptibility to environmental stresses, including increasingly frequent and severe droughts. To test this hypothesis, tree-ring dendroclimatological and stable isotope data were used to assess the physiological responses of acorn-sown, planted, and coppiced 〈em〉Quercus robur〈/em〉 trees of different health classes (healthy, defoliated and recently dead) to interannual climatic variations over the last 41 years. Annual basal area increment (BAI) was negatively and positively related with δ〈sup〉13〈/sup〉C and δ〈sup〉18〈/sup〉O, respectively; although the intensity of these relations depended on tree regeneration origin and current vigor. Compared to healthy oaks, dead acorn-sown oaks exhibited significantly higher BAI, and lower δ〈sup〉13〈/sup〉C and intrinsic water use efficiency (iWUE) during drought periods, but not during non-drought periods; in contrast, dead coppiced oaks showed lower BAI, δ〈sup〉13〈/sup〉C, iWUE and δ〈sup〉18〈/sup〉O irrespective of climatic conditions. Acorn-sown and planted oaks growing fast at early stages of regeneration exhibited sudden decreases in BAI before dying following a severe drought period. In comparison, growth decline preceding the death of coppiced stems was progressive, suggesting that long-term C limitations to increasingly weakened trees underline drought-induced decline and eventual dieback. Different climate sensitivity of 〈em〉Q. robur〈/em〉 trees of different regeneration origin suggests that regeneration forestry practices should be taken into account when adapting forest management plans to climate change.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 November 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 278〈/p〉 〈p〉Author(s): Meiling Sheng, Junzhi Liu, A-Xing Zhu, David G. Rossiter, Haoran Liu, Zhangcong Liu, Liming Zhu〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Process-based crop models are popular scientific tools to study the impacts of environmental conditions and management decisions on crop growth. Some cultivar parameters in crop models cannot be measured directly and need to be estimated. In this research, two most popular Bayesian methods, namely generalized likelihood uncertainty estimation (GLUE) and Differential Evolution Adaptive Metropolis (DREAM), were used for the first time to estimate parameters of the maize module of the Agricultural Productions Systems sIMulator model (APSIM-maize). Both theoretical and real-world evaluations were conducted to compare the performances of these two methods. The maize yields from 2003 to 2006 were used for model calibration, and the yields from 2007 to 2013 were used for model validation. Both GLUE and DREAM performed well in the theoretical and real-world evaluation. During the validation period (2007–2013), when the heteroscedastic model error assumption was adopted in DREAM, on average approximate 90% of observed yield values were captured in the 95% confidence band of DREAM (P-factor = 90.47%), which was larger than that using GLUE (P-factor = 80.93%). Meanwhile the uncertainty bands of DREAM (R-factor = 4.42) were wider than those of GLUE (R-factor = 2.32). If only one parameter set was allowed to be used in the simulation, the weighted mean parameter values according to the likelihood of each parameter set performed better than the parameter set with maximum likelihoods for GLUE while the opposite is true for DREAM. But considering future analysis in the real-world evaluation, the moderate performance of these two methods suggests that a single parameter set obtained by neither GLUE nor DREAM is satisfactory and ensemble simulation is needed. Overall, GLUE and DREAM had similar performance, but GLUE is more convenient and simpler to use than DREAM. So we think GLUE is a better choice than DREAM for estimating cultivar parameters of APSIM-maize.〈/p〉〈/div〉

Description: 〈p〉Publication date: 15 December 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Agricultural and Forest Meteorology, Volume 279〈/p〉 〈p〉Author(s): Wujun Dai, Huiying Jin, Yuhong Zhang, Tong Liu, Zhiqiang Zhou〈/p〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Phenological models can effectively infer historically missing phenological data, so as to investigate the long-term relationship between plants and climate change. Large numbers of ecophysiological and statistical models have been developed in the past few decades, but these models have been unable to make accurate predictions based on external data. Machine learning (ML) methods have an advantage over traditional statistical methods for natural science studies. However, only a few phenological models have been coupled with ML methods. In this study, using long-term leaf unfolding date (LUD) observations collected in Harbin, China, we adopted three popular ML algorithms for predicting plant LUD and compared the performances of 10 phenological models. We detected the temperature sensitivity (ST) of the LUD at the species level for the periods 1962–1987 and 1988–2016 (before and after the recent, sudden warming) and temporal changes in ST with a 15-year moving window for each period. The results show that the gradient boosting decision tree (GBDT) model performs obviously better than the other models for external validation data, while avoiding model overfitting. Most species showed an increase in ST during the 1988–2016 period, and the temporal changes in ST significantly decreased during both periods. The temporal changes in ST from the phenological data predicted by the GBDT model is significantly higher than that of other models, which indicates that the traditional phenological models may underestimate the response of LUD to climate warming. We found a prevalent decline in the magnitude of ST with increasing preseason temperature variance at the species level. Our research suggests that machine learning algorithms should be more widely used in future phenological model research, and temporal changes in ST should be investigated in order to broaden our understanding of plants’ ability to adapt to future climate change.〈/p〉〈/div〉