ALBERT

Description: Publication date: Available online 1 August 2015 Source: Dendrochronologia Author(s): Katarina Čufar, Willy Tegel, Maks Merela, Bernd Kromer, Anton Velušček We present dendrochronological dating of Eneolithic pile dwellings on Ljubljansko barje, Slovenia, from the 4th millennium BC, partly included on the UNESCO world heritage list in 2011. Samples of oak ( Quercus sp.) timbers from the posts on which the dwellings were built have been collected over the past 20 years. They have been dendrochronologically cross-dated and (pre) dated by 14 C wiggle-matching. We describe the construction of a 442-year chronology BAR-3330 based on 106 cross-dated tree-ring series of wood from six pile-dwelling sites. Comparison of BAR-3330 with reference chronologies of more than 500 km distant areas north of the Alps showed that it can be teleconnected and dated with a combined German Swiss chronology. The time span of BAR-3330 was defined in this way as 3771–3330 BC. We were thus able to date exactly building activities on the pile dwellings Strojanova voda (SV), Hočevarica (HO), Maharski prekop (MP), Črešnja pri Bistri (CR), Spodnje mostišče (SM) and Stare gmajne (SG), in which early copper metallurgy played an important role. This is the first dendrochronological dating of prehistoric pile dwellings south of the Alps using reference chronologies from the north based on teleconnection. It provides an opportunity to continue filling the spatial and temporal gaps in the absolute chronology of the 4th millennium BC in the area south and south east of the Alps. Graphical abstract

Description: Publication date: Available online 9 September 2015 Source: Dendrochronologia Author(s): Stefan Krottenthaler, Philipp Pitsch, Gerd Helle, Giuliano Maselli Locosselli, Gregório Ceccantini, Jan Altman, Miroslav Svoboda, Jiri Dolezal, Gerhard Schleser, Dieter Anhuf High-density hardwood trees with large diameters have been found to damage manually operated increment borers, thus limiting their use in the tropics. Therefore, we herein report a new, low-cost gasoline-powered sampling system for high-density tropical hardwood trees with large diameters. This system provides increment cores 15 mm in diameter and up to 1.35 m in length, allowing minimally invasive sampling of tropical hardwood tree species, which, up to the present, could not be collected by conventional 5 or 10 mm increment borers. This system provides a single core sample with ample amount of wood for multidisciplinary analyses, including ring width, stable isotope and wood anatomical measurements. The borer never gets stuck inside stems, even in hollowed trees, cores will never twist during coring, and the gasoline drill gives ample flexibility in the field. It is anticipated that the dendrochronological community will find our technique very useful in the pursuit of tropical tree ring research.

Description: Publication date: Available online 2 April 2015 Source: Dendrochronologia Author(s): H. Gärtner , L. Banzer , L. Schneider , F.H. Schweingruber , A. Bast The type of samples most commonly used in dendro sciences are increment cores of conifers. These cores allow for an easy determination and measurement of ring-width variations over long time periods. For wood anatomical analyses, the cores have to be split into pieces to enable the preparation of high quality micro sections for detailed measurements of cell properties. A major drawback of this procedure is the fact that it is labor intensive and time consuming. We present a new technique enabling the preparation of micro sections of entire increment cores up to a length of 40 cm. For that purpose we combined standard wood-anatomical techniques with the application of Mowiol glue and common Tesa tape. We tested the introduced method on increment cores of Larix decidua Mill. sampled years ago for ring-width analyses to reanalyze them on a microscopic level. The ability to cut these long sections will tremendously reduce the time needed to prepare micro sections. This is of special interest for wood anatomical image analyses of cores used before to create long ring-width chronologies for any kind of environmental reconstructions.

Description: Publication date: Available online 22 March 2016 Source: Dendrochronologia Author(s): Alexander Gradel, Christina Hänsch, Batsaikhan Ganbaatar, Batdorj Dovdondemberel, Ochirragchaa Nadaldorj, Björn Günther The mountain forest steppe and taiga in northern Mongolia have experienced a forest decline in area and quality since the end of the last century. Changes in land use, climate, fire frequency and pest occurrence are considered to be the main drivers of this vegetation shift and desertification. Because this region is the source for major rivers, is home to a unique flora and fauna and represents an important source of timber for Mongolia, the ability of different tree species to respond to these changes and regenerate is of increasing interest. Our contribution focuses on the climate-growth relationship of old and young birch trees from two valleys in the Mongolian province of Selenge Aimag. The research site Bugant, located in the Western Khentey Mountains, was the most important logging centre in Mongolia during socialist times. Today, the vegetation is dominated by succession forests of light taiga. The research site Altansumber, on the border of the Sant and Khushat soum, is dominated by light taiga and mountain forest steppe. Traditional nomads who depend on these forests for different reasons inhabit this area. Wood cores were sampled and chronologies of young and old birch trees at Bugant and Altansumber were created. Climate data were obtained from the Eroo station, which is known in the region for its long and reliable climate record. We analysed the climate-growth relationships of the chronologies from 1962 to 2009. At both sites and in both age classes, correlations with temperature were predominantly negative, particularly in April (Bugant, south- and east-facing slopes) and May (Altansumber, north-facing slopes). Precipitation of the late summer of the previous year (August/September) positively correlated with the growth of birch at Altansumber. We assume that the significant negative correlation between winter precipitation (December/January) and the growth of old birches at both sites is due to positive effects of snow cover on the survival rate of herbivorous insect populations. Our results indicate that during the early vegetation period, younger birch trees are more dependent on water availability than older ones. Negative pointer years were characterized by below-average precipitation during the current summer period and above-average spring temperatures. For the old trees, positive pointer years were characterized by above-average summer precipitation. We conclude that water availability is the most crucial factor for the growth of white birch in northern Mongolia.

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): Luke J. Amos-Binks, David A. MacLean We used dendrochronological analyses to identify periods of natural disturbance and resulting growth responses in 32 mixed species stands in the Acadian forest. Stands represented five different development patterns, based upon 1946 softwood (SW) content (70–80%, termed SW versus 30–60%, termed mixedwood (MW)) and change in SW content from 1946 to 2006: SW-stable, SW-declining, MW-fluctuating, MW-stable, and MW-declining. Standardized growth chronologies were developed from 1163 increment cores sampled from balsam fir ( Abies balsamea ), red spruce ( Picea rubens ), yellow birch ( Betula alleghaniensis ), and sugar maple ( Acer saccharum ). Growth chronologies clearly identified three spruce budworm ( Choristoneura fumiferana ) outbreaks from 1914 to 1921, 1954 to 1961, and 1975 to 1984, and birch dieback from 1938 to 1948. Stand developmental patterns were caused by species characteristics and multiple interacting disturbances, resulting in mortality, growth reductions, releases, and establishment of new cohorts. Balsam fir was present in all stands, but its tendency to establish and release from advanced regeneration following budworm-caused mortality resulted in cyclical proportions of fir in the canopy. Red spruce was less vulnerable to spruce budworm and longer lived, allowing them to persist and better withstand disturbance. Periodic growth index values less than 0.9 for fir and spruce were correlated with mortality of softwoods caused by defoliation, which resulted in release and growth index values >1.1 for sugar maple. Our results demonstrated substantial variation in mixedwood development patterns over a 60-year period within a small (45 km) area.

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): Terje Thun, Helene Svarva Nineteen Norwegian grain chests made of Scots pine ( Pinus sylvestris L.) were analyzed by measuring tree-ring widths on photographs and scanned pictures. Seventeen of the chests were successfully dated by dendrochronology. Two of the dates are corrections of an earlier dating; the ages of these two chests were verified by radiocarbon dating. The grain chests were expected to be medieval, but four, all without carvings, proved to be post-medieval. The mean curve constructed from the dated chests matches all regional Scots pine chronologies in central and southern Norway and several from southern Sweden. All the chests were probably constructed in central Norway. Originally only sixteen chests were known, but several new ones were discovered in the course of this project.

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): Marcelo Pablo Chartier, María Alejandra Giantomasi, Daniel Renison, Fidel Alejandro Roig Soil erosion is a serious problem of land degradation in many parts of the world, and particularly in mountain rangelands. To understand this process it is necessary to develop methods to assess soil erosion rate in a quick, economic and accurate manner. Based on the analysis of exposed Polylepis australis roots, we tested a dendrogeomorphological method for determining soil loss rate in rills and gullies. Few studies considered non-coniferous tree rings in soil erosion analysis and we used, for the first time, an experimental procedure of root exposure and provided a comparison with roots exposed by gully erosion. Our main results showed that as a consequence of soil erosion, exposed roots changed from root-like to a more stem-like wood anatomical structure. The percentage of vessel area per tree-ring area decreases by an average of 22% to 43% during the first and second year after exposure, respectively. Moreover, and during the same time interval, the mean vessel area decreased 32% and 65%, and the number of vessels increased 7% and 48%, respectively. Scars formed at the upper side of the exposed roots are coincident with changes in wood anatomy, and both evidences may be applied to reconstruct an erosion process. This study confirms that the wood anatomy analysis of partially exposed roots can be used to determine the year in which roots are exposed and provides a useful tool to monitor soil erosion rates with a high accuracy.

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): P. Šamonil, J. Timková, I. Vašíčková The use of individual-based models in the study of the spatial patterns of disturbances has opened new horizons in forest ecosystem research. However, no studies so far have addressed (i) the uncertainty in geostatistical modelling of the spatial relationships in dendrochronological data, (ii) the number of increment cores necessary to study disturbance spatial patterns, and (iii) the choice of an appropriate geostatistical model in relation to disturbance regime. In addressing these issues, we hope to contribute to advances in research methodology as well as to improve interpretations and generalizations from case studies. We used data from the beech-dominated Žofínský Prales forest reserve (Czech Republic), where we cored 3020 trees on 74 ha. Block bootstrap and geostatistics were applied to the data, which covered five decades with highly different disturbance histories. This allowed us to assess the general behavior of various mathematical models. Uncertainty in the spatial patterns and stability of the models was measured as the length of the 95% confidence interval (CI) of model parameters. According to Akaike Information Criterion (AIC), the spherical model fitted best at the range of ca. 20 m, while the exponential model was best at the range of ca. 60 m. However, the best fitting models were not always the most stable. The stability of models grew significantly with sample size. At 〈500 cores the spherical model was the most stable, while the Gaussian model was very unstable at 〈300 cores. The pure nugget model produced the most precise nugget estimate. The choice of model should thus be based on the expected spatial relations of the forest ecosystem under study. Sill was the most stable parameter, with an error of ±6–20% for ≥1110 core series. By contrast, practical range was the most sensitive, with an error of at least ±59%. The estimation of the spatial pattern of severe disturbances was more precise than that of fine-scale disturbances. The results suggest that with a sample size of 1000–1400 cores and a properly chosen model, one reaches a certain precision in estimation that does not increase significantly with growing sample size. It appears that in temperate old-growth forests controlled by fine-scale disturbances, it is necessary to have at least 500 cores to estimate sill, nugget and relative nugget, while to estimate practical range at least 1000 cores are needed. When choosing the best model, the stability of the model should be considered together with the value of AIC. Our results indicate the general limits of disturbance spatial pattern studies using dendrochronological and geostatistical methods, which can be only partially overcome by sample size or sampling design.

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): L. Dinis, M.M. Savard, P. Gammon, C. Bégin, J. Vaive This study investigates Pb isotope ratios at low concentrations (parts per billion; ppb) in tree rings and soils in the Northern Athabasca Oil Sands Region (NAOSR), western Canada, to evaluate if: (1) climatic conditions influence on tree-ring Pb assimilation; and (2) such low Pb content allows inferring the regional Pb depositional history. Our results reflect the influence of winter snow cover and the importance of minimum temperature and precipitation in spring and summer on the bioavailability of Pb and its passive assimilation by trees in sub-arctic semi-humid climatic conditions. Winter conditions can influence the state of root systems that subsequently impacts the following growth period, while spring and summer conditions likely control microbial processes and water source, and may thus impact Pb assimilation by trees. Thus, the results of tree-ring Pb concentrations show interesting correlation with cumulated snow from November of the previous year to February ( ρ = 0.53; P 〈 0.01; n = 36). Likewise, the 206 Pb/ 207 Pb ratios inversely correlate with minimum temperature from April to September ( ρ = −0.67; P 〈 0.01; n = 40) and precipitation from May to August ( ρ = −0.42; P 〈 0.01; n = 36). The isotopic results also suggest that the effects of climatic variations are superimposed by regional industrial Pb deposition: Western North American Aerosols (WNAA) and fugitive dust from the oil sands mining operations appear to be the most likely sources. Importantly, this study suggests that even at low Pb concentrations, tree-ring Pb isotopes are modulated by climatic conditions and potential input of regional and long-range transport of airborne Pb. These interpretations open the possibility of using Pb isotopes as an environmental tool for inferring the pollution history in remote regions, and improving our understanding of its natural cycle through the forest environment.

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): Douglas J. Stevenson, Thomas B. Lynch, Pradip Saud, Robert Heineman, Randal Holeman, Dennis Wilson, Keith Anderson, Chris Cerny, James M. Guldin Each year severe winter storms (≈ice storms) damage trees throughout the southern USA. Arkansas and Oklahoma have a history of severe winter storms. To extend that history back beyond the reach of written records, a distinctive tree ring pattern or signature is needed. Storm-caused breakage, branch loss and bending stress provide that signature. We found a severe storm signature in shortleaf pine ( Pinus echinata ). We used three published site chronologies, a set of five new site chronologies from a growth-and-yield study conducted by Oklahoma State University and the unpublished Shortleaf Canyon chronology from a master’s thesis at the University of Arkansas. Our method is based on two ring width values for the first and second growing seasons after the storm standardized to the ring widths of the seven growing seasons after the storm. Concordance between storm years predicted by tree ring patterns and actual storm years was tested using Cohen’s Kappa. Concern about confounding of ice storm signals by droughts led us to test concordance between severe storms and drought in July, August and September; results were inconclusive but stand as a warning that these two phenomena cannot be distinguished with certainty in the tree ring record. Damaging severe storms occurred in about 2.8% of all years. Two out of three storms identified as “severe” produced glaze icing.

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): Julieta Gabriela Arco Molina, Martín Ariel Hadad, Daniel Patón Domínguez, Fidel Alejandro Roig Frost events may damage the cambium and consequently the newly produced tracheids whose cell walls have not yet completed their lignifications, leading to the formation of frost rings. This study deals with the presence of frost rings in Araucaria araucana trees according to cambial age and bark thickness, under the assumption that these factors may be involved in physical or physiological mechanisms that increase resistance to freezing temperatures that impact the cambial tissue. The study was conducted in northern Patagonia at two sites of contrasting geomorphology, and therefore potentially associated with a differential degree of exposure to extreme cold. Wood plus bark cores were extracted from main stems at two heights from the ground and from each of the four cardinal point directions for 30 individuals per site. A Linear Mixed Model and a Generalized Linear Mixed Model were applied in order to relate the bark thickness and the frequency of frost rings in accordance with the different sampling points on the stem. It was observed that as bark becomes thicker with cambial age, the frequency of frost rings decreases, indicating a possible thermal-induced mechanism of bark protection. Consequently, there is an increase in the presence of frost rings at the younger stages of tree life. Although the mechanisms of cold hardiness in trees can be complex, including aspects of the tree physiology, our data indicated that as tree age increases, the thickness of the bark is higher, resulting in a potential effect of isolation and passive protection against the harmful effects of frosts. This mechanism may be relevant in the ecology, conservation and management of forests faced with extreme variability in future climate and changing scenarios.

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): Dominik Florian Stangler, Martin Mann, Hans-Peter Kahle, Elena Rosskopf, Siegfried Fink, Heinrich Spiecker Studying intra-annual wood formation dynamics provides valuable information on how tree growth and forests are affected by environmental changes and climatic extreme events. This study has the aim to evaluate and to quantify synergetic potentials emerging from a combination of current state of the art techniques used to monitor intra-annual wood formation processes. Norway spruce trees were studied in detail during the growing season 2009 with weekly sampling of microcores, high resolution point-dendrometers and wood anatomical analysis. The combination of the applied techniques allowed us to convert the spatial scales of radial tracheid diameter profiles to seasonal time scales and to synchronize fluctuations in intra-annual cell diameter profiles. This spatiotemporal information was used to validate the recently introduced software MICA ( Multiple interval-based curve alignment ) . In comparison to the conventional approach of averaging profiles of tree ring variables, the MICA aligned profiles exhibit a significantly higher synchronicity of the averaged data points. We also demonstrate two new features in the MICA application that enable to extrapolate spatiotemporal information between intra-annual profiles for the construction of robust mean (consensus) profiles that are representative for the population dynamics. By using a set of complementary techniques in an integrated approach, this study highlights a new methodological framework that can contribute to a better understanding of the environmental control of wood formation during the growing season.

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): Filipe Campelo, Cristina Nabais, Ana Carvalho, Joana Vieira Here we present the package tracheideR to standardize profiles of tracheid features, using the R computing environment. This package contains a collection of functions to transform the raw data obtained from image analysis into a tracheidogram to better visualize the radial intra-ring variation of histometric parameters. This procedure is crucial when estimating past weather conditions with a sub-annual resolution, since tracheidograms reflect the influence of fluctuations in weather conditions throughout the growing season (such as temperature and soil water content). The main function of this package is tracheider , which takes as input raw tracheidograms and standardizes them using three different methods. The first method standardizes the number of tracheids from different radial files to the mean number of cells, allowing that different annual rings have different number of cells. The second method normalizes the number of cells of different annual rings to the same number. Finally we present a new method to standardize histometric parameters considering the relative position of the cells within the tree ring. This package was tested using two rings of Pinus pinaster to demonstrate variations between the three methods. According to our results species with high intra- and inter-annual variability, as shown by conifers species growing under Mediterranean climate, should be standardized using the “relative position” method. Finally, we suggest that this new method should be applied to other species to check its potential to detect intra-ring fluctuations in tracheid features and to improve our capacity to detect intra-annual climatic signals.

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): Paolo Cherubini

Description: Publication date: March 2016 Source: Dendrochronologia, Volume 37 Author(s): Jean-Philippe Martin, Daniel Germain Dendrogeomorphology has been recognized as a useful tool to reconstruct past snow avalanche chronologies, especially in remote areas where archives are non-existent. In recent years, there have been a multiplicity of snow avalanche studies based on tree-ring analysis. Yet, the dendrogeomorphic procedure applied to snow avalanches still lacks consensus within the scientific community. This paper illustrates four issues regarding this method encountered on a dataset encompassing 293 trees sampled from 4 sites in the White Mountains (New Hampshire, United States). (1) Separating a sample in an upslope and downslope subgroup allowed to reconstruct a more thorough avalanche chronology. (2) On the other hand, a strong response at a site sheltered from any avalanche track was attributed to extreme snow loadings with a return period well above 100 years. (3) In addition to climatic disturbances, ecological disturbances such as windthrows can cause an anatomical response in the trees similar to snow avalanches. An avalanche track might act as a wind tunnel, making the underlying runout zone a suitable site to windfalls. Sampling in transects can assist in determining the limit between avalanche-related and wind-related disturbances. (4) Early-spring torrential floods and avalanche activities at a multi-process site exhibit distinct spatial patterns in the dendrogeomorphological response that allow discrimination between the two processes in the reconstruction of past chronologies. While the dendrogeomorphologist should be cautious of these issues, their acknowledgement is an opportunity to understand the interactions between the different ecological, climatic and geomorphological processes operating on the forested slopes in the alpine–subalpine environment.

Description: Publication date: Available online 23 February 2016 Source: Dendrochronologia Author(s): Irina P. Panyushkina, Alexei A. Karpukhin, Asya V. Engovatova Investigations of interactions between climate change and humans suffer from the lack of climate proxies directly linked to historical or archaeological datasets that describe past environmental conditions at a particular location and time. We present a new set of pine tree-ring records ( Pinus sylvestris L.) developed from burial timbers excavated at the historical center of Yaroslavl city, Russia. A 171-year δ 13 C tree-ring chronology from AD 1430 to AD 1600 evidences mostly wet summers during the 15th century but exceptionally dry conditions of the 16th century at the Upper Volga catchment. According to the tree-ring record there were four major droughts (〈−1.5 σ ) lasting from 9 to 26 years: 1501–1517, 1524–1533, 1542–1555 and 1570–1596, and major pluvials (>+1.5 σ ) lasting from 70 to 5 years: 1430–1500, 1518–1523, 1534–1541, and 1556–1564. We discuss a plausible contribution of these droughts to crop failures and city fires documented with historical chronicles for the Upper Volga catchment. The devastating drought regime of the 16th century corresponds to the loss of independence of the Yaroslavl principality to the Grand Duchy of Moscow and the formation of the centralized Russian State during the reign of Ivan the Terrible (1533–1584) underpinning the emergence of the Russian Empire. This study substantiates the value of archaeological timbers from the oldest Russian cities and inclusion of stable carbon isotope analysis for understanding hydroclimatic regimes across the mid latitudes of East European Plain, and their relationship to the history of Russia. Graphical abstract

Description: Publication date: Available online 4 February 2016 Source: Dendrochronologia Author(s): James H. Speer, Achim Bräuning, Qi-Bin Zhang, Kambiz Pourtahmasi, Narayan P. Gaire, Binod Dawadi, Prabina Rana, Yub Raj Dhakal, Ram Hari Acharya, Dhruba Lochan Adhikari, Shankar Adhikari, Prakash Chandra Aryal, Damodar Bagale, Binod Baniya, Sanjaya Bhandari, Navin Dahal, Suchana Dahal, Narmandakh Ganbaatar, Anjana Giri, D.B Gurung, Yeshey Khandu, Binu Maharjan, Rajan Maharjan, Rayees Ahmad Malik, Cheryl D. Nath, Bikash Nepal, Justine Ngoma, Ramesh Pant, Mitra Lal Pathak, Hari Paudel, Bimal Sharma, Md Sarwar Hossain, Bayarbaatar Soronzonbold, Thida Swe, Ichchha Thapa, Achyut Tiwari The fieldweek associated with the 4th Asian Dendrochronological Association Conference was an excellent opportunity for education, networking, and research. The participants and group leaders worked together for five days in an area that was new to some of the group leaders and new to some of the participants which enabled us to learn about forest ecology around Kathmandu and Nagarkot, Nepal. The fieldweek was an excellent networking opportunity and the group leaders and participants bonded which strengthened international research in dendrochronology and continues to foster new research collaborations. All of the group leaders and participants had the opportunity to learn about tree-ring formation in Pinus roxburghii at 1500 masl elevation, to explore its wood anatomy, and to examine specific research questions in our field area. In the end we developed a better understanding of the stand-age structure of a stand of trees in Nagarkot, explored the erosion history from exposed roots, and investigated tree health issues on closely related sites. We found that P. roxburghii poses some dating issues with false and micro rings at this elevation, but we were still able to develop a tree-ring chronology from this species and make preliminary assessments of stand dynamics and health.

Description: Publication date: Available online 15 March 2016 Source: Dendrochronologia Author(s): Ekaterina Dolgova Although long-lived trees grow in the Northern Caucasus, no single tree-ring chronology has been reported thus far from this area in the International Tree-Ring Data Base (ITRDB), neither has one been published in international journals. Extensive tree-ring studies were conducted over the last decade, and a tree-ring network was developed for the investigated area. The data on the minimum blue intensity based on 33 series of pine ( Pinus sylvestris L.) and fir ( Abies nordmanniana (Steven) Spach) is presented in this study. The minimum blue intensity (BI) chronology covers the period 1596–2011 with EPS value ≥0.85. The BI chronology strongly correlates with the mean June-September temperature (R = 0.74; p 〈 0.05) from the weather station “Kluhorskij Pereval” (1951–2011). Mean June-September temperature anomalies were reconstructed using the rescaling method. Based on the reconstruction provided in this study the twentieth century is characterized by highly increased June-September temperature. According to this study, the minimum blue intensity approach demonstrates a great potential for paleoclimatic research in the Caucasus. Vast spatial coverage of the new BI-based reconstruction based on data from only two locations in the Northern Caucasus provides prospects for reconstruction of temperature variations for a great region in the Middle East and Northern Africa.

Description: Publication date: Available online 14 December 2015 Source: Dendrochronologia Author(s): Anna V. Taynik, Valentin V. Barinov, Orlan Ch. Oidupaa, Vladimir S. Myglan, Frederick Reinig, Ulf Büntgen Tree-ring research in the Altai-Sayan Mountains so far only considered a limited number of well-replicated site chronologies. The dendroecological and palaeoclimatological potential and limitations of large parts of south-central Russia therefore remain rather unexplored. Here, we present a newly updated network of 13 larch ( Larix sibirica Ldb.) tree-ring width (TRW) chronologies from mid to higher elevations along a nearly 1000 km west-to-east transect across the greater Altai-Sayan region. All data were sampled between 2009 and 2014. The corresponding site chronologies cover periods from 440 to 860 years. The highest TRW agreement is found between chronologies ≥2200 m asl, whereas the material from lower elevations reveals overall less synchronized interannual to longer-term growth variability. While fluctuations in average June–July temperature predominantly contribute to the growth at higher elevations, arid air masses from Mongolia mainly affect TRW formation at lower elevations. Our results are indicative for the dendroclimatological potential of the Altai-Sayan Mountains, where both, variation in summer temperature and hydroclimate can be robustly reconstructed back in time. These findings are valid for a huge region in central Asia where reliable meteorological observations are spatially scarce and temporally restricted to the second half of the 20th century. The development of new high-resolution climate reconstruction over several centuries to millennia will further appear beneficial for timely endeavors at the interface of archaeology, climatology and history.

Description: Publication date: November 2015 Source: Dendrochronologia, Volume 36 Author(s): Maryann R. Pirie, Anthony M. Fowler, Christopher M. Triggs Knowing the number of rings from the pith to the last cross-dated ring on incremental cores is important for regional curve standardisation, for constructing the best chronology by excluding rings formed when the tree was young, and for forest stand dynamics and regeneration studies. As the pith is rarely present on the samples an estimate of the distance to the pith is required. The aim of this paper is to assess the accuracy of three commonly used pith offset estimation methods for estimating pith offsets from kauri incremental cores. Literature identifies three main approaches for estimating pith offsets: Duncan’s geometric method, the concentric circles method (CCM), and the radius–length method. The accuracy of geometric and CMM were assessed using virtual cores constructed from an Agathis australis (Kauri) cross-section. Then the estimates for all three methods were applied to a subset of the kauri incremental cores database. The most accurate method for estimating the pith offset for kauri trees was found to be geometric method, followed by CCM. However, these approaches could only be used to estimate the pith offset for a few cores as they require the core to pass close enough to the pith that there is visible curvature on the cores. For most cores the radius–length method is the only method available for estimating the pith offset. This method relies on the assumption that the pith is located at the geometric centre of the tree which may not be a valid assumption for some species.

Description: Publication date: Available online 11 January 2016 Source: Dendrochronologia Author(s): Lena Hellmann, Leonid Agafonov, Olga Churakova (Sidorova), Elisabeth Düthorn, Ólafur Eggertsson, Jan Esper, Alexander V. Kirdyanov, Anastasia A. Knorre, Pavel Moiseev, Vladimir S. Myglan, Anatoly N. Nikolaev, Frederick Reinig, Fritz Schweingruber, Olga Solomina, Willy Tegel, Ulf Büntgen Arctic driftwood represents a unique proxy archive at the interface of marine and terrestrial environments. Combined wood anatomical and dendrochronological analyses have been used to detect the origin of driftwood and may allow past timber floating activities, as well as past sea ice and ocean current dynamics to be reconstructed. However, the success of driftwood provenancing studies depends on the length, number, and quality of circumpolar boreal reference chronologies. Here, we introduce a Eurasian-wide high-latitude network of 286 ring width chronologies from the International Tree Ring Data Bank (ITRDB) and 160 additional sites comprising the three main boreal conifers Pinus , Larix , and Picea . We assess the correlation structure within the network to identify growth patterns in the catchment areas of large Eurasian rivers, the main driftwood deliverers. The occurrence of common growth patterns between and differing patterns within catchments indicates the importance of biogeographic zones for ring width formation and emphasizes the degree of spatial precision when provenancing. Reference chronologies covering millennial timescales are so far restricted to a few larch sites in Central and Eastern Siberia (eastern Taimyr, Yamal Peninsula and north-eastern Yakutia), as well as several pine sites in Scandinavia, where large rivers are missing though. The general good spatial coverage of tree-ring sites across northern Eurasia indicates the need for updating and extending existing chronologies rather than developing new sites.

Description: Publication date: Available online 4 February 2016 Source: Dendrochronologia Author(s): Achyut Tiwari, Ze-Xin Fan, Alistair S. Jump, Shu-Feng Li, Zhe-Kun Zhou Population structure and tree recruitment dynamics in the natural treeline ecotone of high mountains are strong indicators of vegetation responses to climate. Here, we examined recruitment dynamics of Abies spectabilis across the treeline ecotone (3439–3638 m asl) of Chimang Lekh of Annapurna Conservation Area in the Trans-Himalayan zone of central Nepal. Dendrochronological techniques were used to establish stand age structure by ring counts of adults, and by terminal bud scar count for seedlings and saplings. The results showed abundant seedling recruitment, higher regenerative inertia and colonization with a consistent range shift of the A. spectabilis treeline. The upward expansion of this sub-alpine treeline was found to be driven by a strong dependence of seedling recruitment and radial growth on snowmelt and precipitation as temperatures rise. The radial growth of A. spectabilis at the alpine timberline ecotone (ATE) and closed timberline forest (CTF) showed sensitivity to spring season (March–May) climate. Tree ring indices of CTF showed a strong positive correlation with spring and annual precipitation, and a significant negative correlation with spring and annual temperature, however, moisture sensitivity was less strong at ATE than CTF.

Description: Publication date: Available online 31 December 2015 Source: Dendrochronologia Author(s): Olga V. Churakova (Sidorova), Aleksandr V. Shashkin, Rolf T.W. Siegwolf, Renato Spahni, Thomas Launois, Matthias Saurer, Marina V. Bryukhanova, Anna V. Benkova, Anna V. Kuptsova, Philippe Peylin, Eugene A. Vaganov, Valerie Masson-Delmotte, John Roden Tree-ring width and stable isotopic composition are widely used for the reconstruction of environmental conditions. Eco-physiological models simulating δ 13 C and δ 18 O provide tools to constrain the interpretation of measured tree-ring variations and their relationships to environmental variables. Here, we apply biochemical models of photosynthesis and a model of stomatal conductance to simulate the intra-annual dynamics of δ 13 C values in photo assimilates and tree-rings. We use these models to investigate the physiological responses of larch trees growing on permafrost to variability in precipitation and permafrost depth associated with regional temperature and precipitation changes. Tree-ring width, δ 13 C and δ 18 O in wood and cellulose were measured in larch ( Larix cajanderi Mayr.) samples from northeastern Yakutia (69°N, 148°E) for the period from 1945 to 2004 and used for comparisons with modeled δ 13 C and δ 18 O data. Mechanistic models that quantify physical and biochemical fractionation processes leading to oxygen isotope variation in organic matter are used to identify source water for trees growing on permafrost in Siberia. These models allowed us to investigate the influence of a variety of climatic factors on Siberian forest ecosystem water relations that impact isotope fractionation. Based on δ 13 C and δ 18 O in tree wood and cellulose measurements as well as outputs from different eco-physiological models, we assume that larch trees from northeastern Yakutia can have limited access to the additional thawed permafrost water during dry summer periods.

Description: Publication date: Available online 20 October 2015 Source: Dendrochronologia Author(s): Vladimir V. Shishov, Ivan I. Tychkov, Margarita I. Popkova, Viсtor A. Ilyin, Marina V. Bryukhanova, Alexander V. Kirdyanov It is generally assumed in dendroecological studies that annual tree-ring growth is adequately determined by a linear function of local or regional precipitation and temperature with a set of coefficients that are temporally invariant. However, various researchers have maintained that tree-ring records are the result of multivariate, often nonlinear biological and physical processes. To describe critical processes linking climate variables with tree-ring formation, the process-based tree-ring Vaganov–Shashkin model (VS-model) was successfully used. However, the VS-model is a complex tool requiring a considerable number of model parameters that should be re-estimated for each forest stand. Here we present a new visual approach of process-based tree-ring model parameterization (the so-called VS-oscilloscope) which allows the simulation of tree-ring growth and can be easily used by researchers and students. The VS-oscilloscope was tested on tree-ring data for two species ( Larix gmelinii and Picea obovata ) growing in the permafrost zone of Central Siberia. The parameterization of the VS-model provided highly significant positive correlations ( p 〈 0.0001) between simulated growth curves and original tree-ring chronologies for the period 1950–2009. The model outputs have shown differences in seasonal tree-ring growth between species that were well supported by the field observations. To better understand seasonal tree-ring growth and to verify the VS-model findings, a multi-year natural field study is needed, including seasonal observation of the thermo-hydrological regime of the soil, duration and rate of tracheid development, as well as measurements of their anatomical features.

Description: Publication date: Available online 30 October 2015 Source: Dendrochronologia Author(s): Vladimir Matskovsky, Andrey Dolgikh, Konstantin Voronin Dendrochronology is usually the only method of precise dating of unsigned art objects made on or of wood. It has a long history of application in Europe, however in Russia such an approach is still at an infant stage, despite its cultural importance. Here we present the results of dendrochronological and radiocarbon accelerated mass spectrometry (AMS) dating of three medieval icons from the 15th–17th century that originate from the North of European Russia and are painted on wooden panels made from Scots pines. For each icon the wooden panels were dendrochronologically studied and five to six AMS dates were made. Two icons were successfully dendro-dated whereas one failed to be reliably cross-dated with the existing master tree-ring chronologies, but was dated by radiocarbon wiggle-matching. Wiggle-matching of radiocarbon dates is the most promising method for dating Russian icons in the absence of a dense dendrochronological network. However, for this case uncertainties connected with the radiocarbon method have to be taken into account and further studies of these uncertainties must be undertaken by comparing dendro-dated and radiocarbon-dated wooden works of art. Our results, moreover, showed that in two cases art-historical dates were by five to ten decades older than the earliest possible time of the creation of the icons, based on dendrochronology.

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〉