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  • Artikel  (27.145)
  • Canadian Science Publishing  (14.226)
  • De Gruyter  (12.919)
  • Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft  (21.646)
  • Wirtschaftswissenschaften  (5.499)
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  • 1
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    Workplace Heterogeneity and the Returns to Versatility (2021)
    De Gruyter
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    Publikationsdatum: 2021-08-20
    Beschreibung: In the canonical random on-the-job search model with continuous firm heterogeneity, I show that a mean-preserving spread of the firm-productivity distribution raises the returns to mobility, i.e., the inter-firm mobility of workers as measured by the number of outside contacts per employment spell. Both sorting and rent-share mechanisms play a role. In a further contribution, I distinguish frictional and structural impediments to mobility in order to establish a link between mobility and skills via the concept of versatility. Versatility enhances a person’s mobility since a mismatch between job requirements and the person’s skill set is less likely to occur. I provide some statistics in support of the discussed mechanisms. The findings are particularly intriguing in light of the concurrent rise in the productivity dispersion across firms and in the skill premium in many countries.
    Print ISSN: 2194-6124
    Digitale ISSN: 1935-1704
    Thema: Wirtschaftswissenschaften
    Publiziert von De Gruyter
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  • 2
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    Testing for stationarity with covariates: more powerful tests with non-normal errors (2021)
    De Gruyter
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    Publikationsdatum: 2021-03-29
    Beschreibung: Previous studies suggested that the power of unit root and stationarity tests can be improved by augmenting a testing regression model with stationary covariates. However, one practical problem arises since such procedures require finding the variables that satisfy certain conditions. The difficulty of finding satisfactory covariate has hindered using such desired tests. In this paper, we suggest using non-normal errors to construct stationary covariates in testing for stationarity. We do not need to look for outside variables, but we utilize the distributional information embodied in a time series of interest. The terms driven from the information on non-normal errors can be employed as valid stationary covariates. For this, we adopt the framework of stationarity tests of Jansson (Jansson, M. 2004. “Stationarity Testing with Covariates.” Econometric Theory 20: 56–94). We show that the tests can achieve much-improved power. We then present the response surface function estimates to facilitate computing the critical values and the corresponding p-values. We investigate the nature of shocks to the US macro-economic series using the updated Nelson–Plosser data set through our new testing procedure. We find stronger evidence of non-stationarity than their univariate counterparts that do not use the covariates.
    Print ISSN: 1081-1826
    Digitale ISSN: 1558-3708
    Thema: Mathematik , Wirtschaftswissenschaften
    Publiziert von De Gruyter
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  • 3
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    Nitrogen and phosphorus distribution in plant, soil and leachate as affected by liquid hog manure and chemical fertilizers (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-03-22
    Beschreibung: A two-year field study was conducted on a coarse textured soil in Manitoba, Canada, to investigate the effects of liquid hog manure (LHM) and chemical fertilizer application on barley (2005) and red spring wheat (2006) yields, crop nutrient uptake and nitrogen (N) and phosphorus (P) movement to the environment. The treatments were LHM applied at two rates as 22000 L ha-1 (2500 gal ac-1, abbreviated as M2500) and 43000 L ha-1 (5000 gal ac-1, abbreviated as M5000) and two rates of chemical fertilizer to match total N and P in LHM treatments, F2500 and F5000, along with an unamended control. The M5000 and M2500 treatments showed similar grain yield and N and P uptake. However, M5000 and M2500 significantly increased grain yield by 67% and 78%, respectively, compared to the control in 2005. In 2006, wheat grain yields from M2500 and M5000 were 71% and 86% greater than the control. In 2005, leachate NO3-N concentrations and leaching loads were higher with chemical fertilizers than M2500. In 2005, the apparent recovery of applied N as leachate was 35% and 23% in F5000 and F2500 treatments, whereas it was 6% and 7% of applied N in M5000 and M2500 plots, respectively. However, the application of M5000 resulted in P accumulation near the surface and may increase the potential risk of P loss with runoff. Our results show that applying LHM at moderate rates (M2500) may ensure desirable crop yields comparable to higher rates of nutrient application with minimal potential losses relative to higher rates.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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  • 4
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    Is the annual maximum leaf area index an important driver of water fluxes simulated by a land surface model in temperate forests? (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-03-24
    Beschreibung: In land surface models, vegetation is often described using plant functional types (PFTs), a classification that aggregates plant species into a few groups based on similar characteristics. Within-PFT variability of these characteristics can introduce considerable uncertainty in the simulation of water fluxes in forests. Our objectives were to (i) compare the variability of the annual maximum leaf area index (LAImax) within and between PFTs and (ii) assess whether this variability leads to significant differences in simulated water fluxes at a regional scale. We classified our study region in southwestern Quebec (Canada) into three PFTs (evergreen needleleaf, deciduous broadleaf, and mixed forests) and characterized LAImax using remotely sensed MODIS-LAI data. We simulated water fluxes with the Canadian Land Surface Scheme (CLASS) and performed a sensitivity analysis. We found that within-PFT variability of LAImax was 1.7 times more important than variability between PFTs, with similar mean values for the two dominant PFTs, deciduous broadleaf forests (6.6 m2·m−2) and mixed forests (6.3 m2·m−2). In CLASS, varying LAImax within the observed range of values (4.0–7.5 m2·m−2) led to changes of less than 2% in mean evapotranspiration. Overall, LAImax is likely not an important driver of the spatial variability of water fluxes at the regional level.
    Print ISSN: 0045-5067
    Digitale ISSN: 1208-6037
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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  • 5
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    Influence of Continuous Application of Feedlot Manure and Legacy Treatments on Soil Organic Carbon, Soil Hydrophobicity, and Soil Water Repellency (2021)
    Canadian Science Publishing
    Details
    Publikationsdatum: 2021-03-22
    Beschreibung: Continuous or discontinued manure applications to agricultural soils may impact soil organic carbon (SOC) and water balances because of manure carbon inputs and the potential for manure-induced soil hydrophobicity (SH) and soil water repellency (SWR). A laboratory study was conducted using a long-term (44 yr) field experiment on a clay loam soil to determine the effect of application rate of feedlot manure under dryland (0, 30, 60, and 120 Mg ha-1 wet wt.) and irrigation (0, 60, 120, 180 Mg ha-1) on SOC, SH and SWR. In addition, we compared the effect of 44 yr of continuous annual manure applications (C44) to legacy treatments which had discontinued applications for 14 yr (D14) or 30 yr (D30). Laboratory measurements were conducted on air-dried and sieved ( 1.95) SWR. Manure application rate had a significant (P ≤ 0.05) and positive effect on SOC and SH, and both followed an exponential model. In contrast, RI had a negative response to application rate under dryland and had no response under irrigation. Overall, positive responses of SOC and SH to application rate supported our hypothesis, but it was not supported for RI. The hypothesis of greater SOC, SH, and RI for continuous versus discontinued treatments was also supported for SOC and SH, but not for RI.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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  • 6
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    Improvement of root morphological characteristics on water percolation rate in grassland soils of Yellow River riparian buffer strips (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-03-22
    Beschreibung: Soil water percolation is an important process required to meet plant water needs, determine soil water storage, and affect soil water quality in riparian buffer strips. However, the effects of plant roots on soil percolation in riparian buffer strips are not totally understood, and contradictory results have been carried out on the effects of the root system on soil percolation rates. This study aimed to investigate soil percolation in natural grasslands and evaluate the relationships between root morphological characteristics and percolation rates. Path analysis was used to provide information on the relative contribution of root characteristics on soil percolation rates. Three mixed grasslands (Imperata cylindrica + Phragmites australis, Imperata cylindrica + Cynodon dactylon, Imperata cylindrica + Juncellus serotinus) were selected in the Yellow River wetland natural reserves of Zhengzhou. Soil percolation rates (initial, average and steady infiltration rates) were measured by using double-ring methods, and plant root morphological characteristics were analyzed. Soil percolation rates and plant root characteristics parameters of Imperata cylindrica + Phragmites australis and Imperata cylindrica + Cynodon dactylon were higher than those of Imperata cylindrica + Juncellus serotinus. Initial percolation rate of Imperata cylindrica + Phragmites australis and Imperata cylindrica + Cynodon dactylon at 0-10cm depth was 58.06% and 95.55% higher than that of Imperata cylindrica + Juncellus serotinus, respectively. Percolation rates had a significant positive correlation with root characteristic parameters, and the main factor controlling soil percolation rates was root volume density. Mixed natural grasslands with more root volume density improved soil infiltration and percolation rates.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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  • 7
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    Reducing peat in growing media: impact on N content, microbial activity and CO2 and N2O emissions (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-03-10
    Beschreibung: Renewable materials including coir, biochar and composts are investigated worldwide in the horticultural industry to partially substitute peat in growing media. In this study, we assessed the effects of biochar and vermicompost as partial substitution of peat, and compared these peat-based growing media with coir in terms of NH4+-N and NO3--N content, CO2-C and N2O-N emissions and their microbial biomass carbon (MBC) and nitrogen (MBN). Six growing media mixtures (peat; peat+biochar 9:1 v/v; peat+vermicompost 9:1 v/v; coir; coir+biochar 9:1 v/v; coir+vermicompost 9:1 v/v) replicated three times were incubated in growth chambers during a 60-days period. At day 0 of incubation (DAI), peat amended with biochar retained around 12.81% of NH4+-N compared with peat alone. The concentrations of NO3--N peaked at 275 mg kg–1 at 33 DAI for peat and 552 mg kg–1 at 46 DAI for coir amended with vermicompost. The substitution of peat with biochar resulted in large CO2-C (2070 µg CO2-C g–1 dry weight (dw)) and N2O-N (62.78 µg N2O-N g–1 dw) emissions, but not coir. The substitution of coir with vermicompost increased N2O-N emissions at a much lower level (47.53 µg N2O-N g–1 dw) than peat (111.82 µg N2O-N g–1 dw). Our results showed that supplements of vermicompost in peat and coir improved N supply which could benefit plant growth, while substituting part of peat with biochar increased CO2-C and N2O-N emissions. In contrast, no effect of biochar was observed with coir, which is beneficial for the environmental footprint of short-cycle growing crops.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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  • 8
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    A new generation of sensors and monitoring tools to support climate-smart forestry practices (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-03-16
    Beschreibung: Climate-smart forestry (CSF) is an emerging branch of sustainable adaptive forest management aimed at enhancing the potential of forests to adapt to and mitigate climate change. It relies on much higher data requirements than traditional forestry. These data requirements can be met by new devices that support continuous, in-situ monitoring of forest conditions in real time. We propose a comprehensive network of sensors, i.e. a wireless sensor network (WSN), that can be part of a world-wide network of interconnected uniquely addressable objects, an Internet of Things (IoT), which can make data available in near real time to multiple stakeholders, including scientists, foresters, and forest managers, and may partially motivate citizens to participate in big data collection. The use of in-situ sources of monitoring data as ground-truthed training data for remotely sensed data can boost forest monitoring by increasing the spatial and temporal scale of the monitoring, leading to a better understanding of forest processes and potential threats. Here, some of the key developments and applications of these sensors are outlined, together with guidelines for data management. Examples are given of their deployment to detect early warning signals (EWS) of ecosystem regime-shifts in terms of forest productivity, health and biodiversity. Analysis of the strategic use of these tools highlights the opportunities for engaging citizens and forest managers in this new generation of forest monitoring.
    Print ISSN: 0045-5067
    Digitale ISSN: 1208-6037
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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  • 9
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    Eurobonds: Three Lessons from China’s “Debt Centralization/Decentralization” Experience (2021)
    De Gruyter
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    Publikationsdatum: 2021-03-12
    Beschreibung: Eurobonds, dubbed as Coronabonds in the context of the current coronavirus crisis, are being hotly debated among the euro area member states amid the COVID-19 pandemic. The debate is in many ways a retread of the euro area sovereign debt crisis of 2011–2012. As China’s “debt centralization/decentralization” experience is comparable with the introduction of Eurobonds in the European Union (EU) in terms of institutional mechanism design, we review our previous series of studies of China’s “debt centralization/decentralization” experience to shed some light on the Eurobonds debate. We obtain three key lessons. First, the introduction of Eurobonds in EU is likely to soften the budget constraint of the governments of the euro area member states. Second, it is also likely to strengthen the moral hazard incentives of the governments of the euro area member states to intentionally overstate their budget problems. Finally, the magnitudes of the moral hazard effects generated by the introduction of Eurobonds in EU are likely larger than their respective counterparts in China.
    Digitale ISSN: 1553-3832
    Thema: Wirtschaftswissenschaften
    Publiziert von De Gruyter
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  • 10
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    Effects of ionized brackish water and polyacrylamide application on infiltration characteristics and improving water retention and reducing soil salinity (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-02-17
    Beschreibung: There is an urgent need for brackish groundwater-based irrigation methods to be developed for saline soils that are effective, economically advantageous, and environmentally friendly. The use of both ionized brackish water and polyacrylamide (PAM) might provide such a method. The long-term use of brackish water irrigation can lead to the secondary salinization of soil and, as a consequence, restrict the development of the agricultural economy. Here, we conducted one-dimensional vertical infiltration experiments to examine the effects of ionized brackish water and PAM on soil infiltration characteristics. The result indicated that the water retention of soil first increased and then decreased with the increased in PAM application rates. The maximum water retention of soil was obtained in PAM application of 0.04% for ionized brackish water treatment. Soil water storage for the 0.04% PAM application under ionized brackish water irrigation was the highest and 5.1% higher compared with non-ionized brackish water at a PAM application rate of 0.04%. The ionized brackish water treatment at a PAM application rate of 0.04% improved the desalinization efficiency by 2.3% compared with non-ionized brackish water treatment. Thus, ionized treatment and PAM application are effective for improving the characteristics of soil water and salt transport and permit the safe use of brackish groundwater for irrigation.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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  • 11
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    Stand density management diagrams: modelling approaches, variants, and exemplification of their potential utility in crop planning (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-02-01
    Beschreibung: The evolving shift in forest management objectives towards the collective consideration of volumetric yield, end-product quality and value, and ecosystem service outcomes, while accounting for the impacts of anthropogenic climate change, has resulted in innovative advancements in decision-support models used in stand density management. This review provides a synopsis of these efforts with respect to static, dynamic, and structural stand density management diagrams (SDMDs). More precisely, the scope of this review includes an ecology-based perspective of stand density management, summarization of the foundational quantitative relationships along with their utilization within the analytical structure of the SDMD, examination of SDMD compliance with underlying ecological constructs and empirical prediction expectations, exemplification of a climate-sensitive structural SDMD variant in boreal crop planning, and identification of outstanding analytical challenges and plausible future research directions for advancing the SDMD modelling approach and its utility in stand-level management planning. Collectively, this account of the conceptual basis, historical analytical evolution, ecological integrity, predictive ability, application diversity, and demonstrated utility of the various SDMD variants solidifies the prerequisite evidentiary foundation for the continued development and deployment of SDMD-based crop planning decision-support models.
    Print ISSN: 0045-5067
    Digitale ISSN: 1208-6037
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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  • 12
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    Predicting soil nitrogen availability to grain corn in Ontario, Canada (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-03-10
    Beschreibung: Predicting the soil available nitrogen (N) to grain corn over a growing season in humid temperate regions is the key for improving fertilizer N recommendations. The objective of this study was to evaluate a suite of soil-N tests to predict soil N availability to grain corn over two growing seasons at 13 individual sites with long-term history of synthetic N fertilization in Ontario, Canada (13 site-years). At each site, fertilizer N was applied at various rates (0-224 kg N ha-1) to determine the crop response to N fertilizer, relative yield (RY) and the most economic rate of N (MERN). Across the entire dataset, water-extractable mineral N (WEMN) was the only soil test that strongly correlated to both RY (r = 0.74**) and MERN (r = -0.56*) indicating that in grain corn fields with long-term history of N fertilization, mineral forms of N in soil solution can be used for fertilizer N recommendations in southern and eastern Ontario. We also provide evidence that grouping soils based on clay content could further refine fertilizer-N recommendations for grain corn in Ontario. A multi-year validation of the WEMN test with more field sites and development of a fertilizer recommendation table for this soil test are recommended.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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  • 13
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    Entry Deterrence and Free Riding in License Auctions: Incumbent Heterogeneity and Monotonicity (2021)
    De Gruyter
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    Publikationsdatum: 2021-03-11
    Beschreibung: We examine free riding for entry deterrence in license auctions with heterogeneous incumbents. We establish the monotonicity of randomized preemptive bidding equilibria: an incumbent with a higher entry-loss rate has greater free-riding incentive, choosing a lower deterring probability. We then identify conditions for the existence of a series of fully or partially participating equilibria such that two or more incumbents with bounded heterogeneity in their entry-loss rates participate in randomized preemptive bidding. As an application, we examine a simple case of a bipartite group of participating incumbents consisting of one “leader” and many “followers”. We show that the policy of limiting the leader’s participation (set-asides for entrants, limiting participation of incumbents with excessive market shares, etc.) may or may not increase entry probability.
    Print ISSN: 2194-6124
    Digitale ISSN: 1935-1704
    Thema: Wirtschaftswissenschaften
    Publiziert von De Gruyter
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  • 14
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    Evaluation of a combination of phosphorylated fibers and zeolite as a potential substitute to synthetic wetting agents in peat moss products (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-02-17
    Beschreibung: Water availability and pH are important factors to consider to determine the suitability of a material for use as a growing medium. Unfortunately, most horticultural substrates are characterized by their water repellency. This is the case with peat moss which is hydrophobic and acidic. Synthetic surfactants are required to improve its wettability. In this study, a combination of phosphorylated wood pulp fibers (FLP) and zeolite is proposed as a substitute to surfactants to increase the wettability of peat moss in the presence of lime, an additive generally used as fertilizer or pH regulator. Results show that lime reduces the water retention capacity of FLP. However, the addition of 15% zeolite to the peat moss/FLP system increases the pH and water retention of the substrate. The negative effect of the presence of 1 wt. % lime on the water retention of the peat moss/FLP mixture was corrected by zeolite addition. Optimal conditions were obtained at 10% zeolite for the two types of lime tested with favorable pH and water retention capacity values. Zeolite was shown to have a higher affinity than FLP for calcium ions preventing the detrimental interaction between FLP and calcium ions.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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  • 15
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    COVID Social Distancing and the Poor: An Analysis of the Evidence for England (2021)
    De Gruyter
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    Publikationsdatum: 2021-02-16
    Beschreibung: Social distancing is a matter of individuals’ choices as well as of regulation. We analyse weekly panel data on such behaviour for English Upper Tier Local Authorities (UTLAs) from March to July 2020, paying attention to the influence of poverty, as measured by free school meals provision. Panel regressions suggest that, although more stringent regulation and slightly lagged local cases of infection increase social distancing, both effects are weaker in UTLAs with higher levels of poverty, in part because of poor housing, and also because shortage of money has forced the poor to keep working. Thus motivated, we develop a two-class (rich/poor) model, in which a Nash non-cooperative equilibrium arises from individual choices in a regulatory regime with penalties for non-compliance. The model yields results in keeping with the empirical findings, indicating the desirability of generous measures to furlough workers in low-paid jobs as a complement to the stringency of general regulation.
    Print ISSN: 2194-6116
    Digitale ISSN: 1935-1690
    Thema: Wirtschaftswissenschaften
    Publiziert von De Gruyter
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  • 16
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    Phosphorus saturation index and water-extractable phosphorus in high-legacy phosphorus soils in southern British Columbia, Canada (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-03-03
    Beschreibung: Understanding of the risk of phosphorus (P) loss to the environment is crucial to monitor soil P and implement policies for P management. We assessed P sorption characteristics and adapted a P saturation index (PSI) for silage corn and blueberry fields in south coastal British Columbia (BC), Canada. We used 284 composite soil samples with contrasting P levels collected from eight silage corn and 23 blueberry fields across south coastal BC. The P sorption maximum (Smax) varied between 982 and 2532 mg P·kg−1 and was influenced by aluminum concentration and organic matter content. The degree of P saturation was related to water-extractable P (Pw) by a quadratic regression with R2 = 0.85. A critical Pw = 3.7 mg·kg−1 was established across the two cropping systems. The silage corn fields with pH 〉 5.5 had critical PSI value of 10.4%, and blueberry fields with pH 
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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  • 17
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    Quantifying the vertical diversification development stage of old-growth Douglas-fir to derive stage-specific targets for restoration silviculture (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-03-01
    Beschreibung: Structural variability in natural Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco) forests hinders restoration targets for the full old-growth developmental sequence. To guide stage-specific restoration, we present a new approach toward developing a simple index of the vertical diversification (VD) stage. VD-associated sub-stand structures were objectively identified by quantifying the size structures of live trees across a developmental sequence of 10 pristine stands in the Oregon Cascades, USA. Floating neighborhoods were used to delineate natural tree neighborhoods based on triangulated irregular networks in five concentric rings of ever-greater spatial extent (averaging 60–2060 m2). Diameter distributions summarized the most frequently encountered tree size structures among neighborhoods, with increasing deviation from the neutral multi-variate core. Of 18 observed diameter distribution types (DDTs), the core DDT characterized all-sized tree neighborhoods reflective of vertical diversification, which was most abundant in early old-growth (VD) stands and least abundant at the extremes of the sequence. VD declined in older stands, whose more distinct DDTs had peaks in larger trees and multiple size classes, likely reflecting horizontal diversification (HD). This new approach illustrates that structural restoration of VD stands could be facilitated by the single-tree selection method, while that of HD stands may be promoted with both single-tree and group selection as well as targeted release.
    Print ISSN: 0045-5067
    Digitale ISSN: 1208-6037
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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  • 18
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    Soybean and soil responses to biochar amendment in controlled environments with elevated temperature and carbon dioxide (2021)
    Canadian Science Publishing
    Details
    Publikationsdatum: 2021-03-03
    Beschreibung: Warmer atmospheric temperatures (eT) will increase plant nutrient uptake, and elevated atmospheric CO2 (eCO2) is expected to enhance plant growth, whereas a multicomponent eTeCO2 effect should also be beneficial for agroecosystems. Our goal was to understand if single- (eT, eCO2) or multicomponent (eTeCO2) climate effects, predicted for southern Ontario, Canada, will affect soybean and soil properties differently when soil is amended with manure and biochar (MB) or with manure, nitrogen (N) fertilizer, and biochar (MNB) compared with the addition of manure and N fertilizer (MN). We hypothesized that biochar regulates climate effects and causes soybean and soil properties to be similar to ambient climate conditions than soil without biochar. However, soil amended with biochar functioned independently of single- or multicomponent climate effects. Soybean pod and shoot biomass, shoot height, and shoot:root ratio were greater (p 
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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    Crypto-assets portfolio selection and optimization: a COGARCH-Rvine approach (2021)
    De Gruyter
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    Publikationsdatum: 2021-03-26
    Beschreibung: Blockchain is a new technology slowly integrating our economy with crytocurrencies such as Bitcoin and many more applications. Bitcoin and other version of it (known as Altcoins) are traded everyday at various cryptocurrency exchanges and have drawn the interest of many investors. These new type of assets are characterised by wild swings in prices and this can lead to great profit as well as large losses. To respond to these dynamics, crypto investors need adequate tools to guide them through their choice of optimal portfolio selection. This paper presents a portfolio selection based on COGARCH and regular vine copula which are able to capture features such as abrupt jumps in prices, heavy-tailed distribution and dependence structure respectively, with the optimal portfolio achieved through the stochastic heuristic algorithm differential evolution known for its global search solution ability. This method shows great performance as compared with other available models and can achieve up to 50% of total returns in some periods of optimization.
    Print ISSN: 1081-1826
    Digitale ISSN: 1558-3708
    Thema: Mathematik , Wirtschaftswissenschaften
    Publiziert von De Gruyter
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    When is Knowledge Acquisition Socially Beneficial in the Laffont–Tirole Regulatory Framework? (2021)
    De Gruyter
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    Publikationsdatum: 2021-03-22
    Beschreibung: The Laffont–Tirole regulator observes the accounting costs of a firm but she can neither observe its true cost-type nor its chosen effort level. This paper considers a Laffont–Tirole regulator who could employ an expert to obtain better, albeit not perfect, knowledge about the firm’s true cost type. Both the welfare gains through superior allocations from better knowledge but also the knowledge acquisition costs increase in the ‘marginal deadweight losses from taxes’ parameter λ ≥ 0. We derive a closed-form expression of the overall welfare benefits from knowledge acquisition as a function in λ. We characterize parameter conditions such that knowledge acquisition could improve social welfare in dependence on the value of λ. For this case we show that knowledge acquisition strictly increases social welfare if and only if λ falls into the interval (λ *, ∞) whereby we present a sharp characterization of the critical threshold-value λ * ≥ 0. In other words, information acquisition through a regulator only increases welfare for economies with comparatively high deadweight losses from taxation whereas welfare is decreased whenever these deadweight losses are low.
    Print ISSN: 2194-6124
    Digitale ISSN: 1935-1704
    Thema: Wirtschaftswissenschaften
    Publiziert von De Gruyter
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    Wood density variation in naturally regenerated stands of Pinus ponderosa in northern Arizona, USA (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-03-22
    Beschreibung: In the southwestern United States, land managers are implementing large-scale forest restoration projects involving treatments designed to improve forest health, protect ecosystem services, and reduce the risk of catastrophic wildfire in overstocked ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws.) forests. A better understanding of wood properties is necessary to improve the currently limited markets for the woody byproducts generated by these treatments. Therefore, our objective was to investigate variations in ponderosa pine wood density across the northern Arizona landscape. We sampled trees from 18 naturally regenerated stands and used X-ray densitometry to quantify the radial and axial variation within and among trees. We modeled within-stem wood density patterns using generalized additive models, and investigated the effects of climatic variation using response function analyses. Additionally, we tested the effects of site-level predictors on whole-tree wood density. We found high variability in radial wood density profiles among trees in our stands compared with that observed in studies of other species grown in plantations — perhaps due to high genetic variation within naturally regenerated stands. Wood density was negatively correlated with precipitation at annual and most quarterly intervals, except for a positive correlation with late-summer monsoon precipitation. The high wood density variation we found among trees highlights the need for further investigation of controls over wood properties in natural nonplantation forests.
    Print ISSN: 0045-5067
    Digitale ISSN: 1208-6037
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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    Cattle manure loadings and legacy effects on Cu and Zn availability under rainfed and irrigated conditions (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-02-03
    Beschreibung: Long term cattle manure applications build up nutrient pools and can lead to trace element enrichments in soils. The objectives of this study were to evaluate Cu and Zn loadings in the soil during continuous annual cattle manure applications and determine the time required for soil to return to its pre-manure available Cu and Zn levels after manure is discontinued. The manure application rates were 0, 30, 60, and 90 Mg ha-1 for rainfed and 0, 60, 120, and 180 Mg ha-1 (wet weight) for irrigated plots. While manure was applied for 45 years in some plots, applications were terminated in one subset of treatments after 14 years and in another subset after 30 years to study legacy effects after 31 and 15 years, respectively. Soil samples were collected in the fall of 2003, 2008, 2013, and 2018 and analyzed for available Cu and Zn. Crops were grown in all years continuously with Cu and Zn concentrations measured in both silage and grains harvested. The regression model developed using data collected suggests long legacy effects with recovery time to pre-manure levels ranging from 10-20 years for Cu and 23-41 years for Zn at irrigated and 10-24 for Cu and 21-32 years for Zn under rainfed, respectively. Long term applications of cattle manure could lead to accumulation of Cu and Zn, creating long-lasting legacy effects in soils with the increased environmental risk of leaching to groundwater
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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    Effect of temperature on microbial residue dynamics in a temperate farmland soil (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-02-03
    Beschreibung: Microorganisms mediate soil organic carbon (SOC) turnover, and microbial residues contribute a significant portion to SOC storage in temperate agroecosystems. However, little is known about the direct effect of temperature on microbial residues associated with SOC sequestration/decomposition. We assessed microbial residue dynamics in a 28 d incubation conducted at four temperatures (5, 15, 25, and 35 °C). Microbial residues did not change with time from 5 to 25 °C. However, at 35 °C, fungal residues decomposed significantly with time, and the decomposition rate was higher than SOC. Considering the important contribution of fungal residues to stable-C pool, our findings indicated warming may be detrimental to C stability in this temperate soil.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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    Seeds of change? Seed transfer governance in British Columbia: insights from history (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-02-01
    Beschreibung: Tree seed transfer is critical to effective reforestation programs, and exploring its policy roots provides insights to understand future, and potentially controversial, actions like assisted migration. We offer a historical overview of seed transfer governance in British Columbia, Canada, by applying analytics from the policy change and knowledge co-production literatures. Based on document analysis and semi-structured interviews with key informants, we trace governance attributes to examine how and why policies have changed (or not) over time. We reveal a paradigmatic shift in seed transfer governance, culminating in a climate-based seed transfer system — informed largely by genetic knowledge — that emerged through a policy window opening. In contrast, governance processes remained relatively unchanged in practice, including the disproportionately influential role of the forest industry in policy-making. These insights shed light on the legacies of a government–industry policy coalition that influence underlying seed transfer objectives (i.e., forest productivity), and help to explain the ongoing dominance of particular knowledge forms used to inform policy. We highlight the need for increased contributions from a wider range of expertise, stakeholders, and rights holders in developing seed transfer policies for future forests.
    Print ISSN: 0045-5067
    Digitale ISSN: 1208-6037
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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    The Intended and Unintended Effects of Opioid Policies on Prescription Opioids and Crime (2021)
    De Gruyter
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    Publikationsdatum: 2021-01-22
    Beschreibung: In response to the opioid crisis, US states have implemented policies to reduce the dispensing of opioids and curb drug mortality. Exploiting a long panel of county-level data, we analyse the combination of demand- and supply-side state opioid policies and evaluate their effect on opioids per capita dispensed and their unintended fallouts on drug-related crime. We demonstrate that only laws targeting the supply for opioids reduce the volume of prescribed drugs, while demand-side policies are less effective. We also emphasize that within supply-side state regulations, Pain Management Clinics Laws are the most successful in reducing the dispensation of prescription opioids. Remarkably, the drop in opioids distributed due to supply-side regulations is accompanied by negative externalities in the local market for illicit drugs.
    Digitale ISSN: 1935-1682
    Thema: Wirtschaftswissenschaften
    Publiziert von De Gruyter
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  • 26
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    Frontmatter (2021)
    De Gruyter
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    Publikationsdatum: 2021-01-01
    Digitale ISSN: 1935-1682
    Thema: Wirtschaftswissenschaften
    Publiziert von De Gruyter
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    Effects of warming and oxalic acid addition on plant–microbial competition in Picea brachytyla (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-02-16
    Beschreibung: The importance of oxalic acid for tree seedling growth and the competition for inorganic nitrogen (N) by plants and soil microorganisms under warming was investigated using 15N tracer techniques in Picea brachytyla (Franch.) E. Pritz. Results showed that warming combined with oxalic acid application induced growth enhancements in seedlings primarily through increases in fine root length and fine root surface area. Moreover, soil NH4 +, NO3 –, PO4 3–, N mineralization, microbial biomass carbon (MBC), and microbial biomass nitrogen (MBN) were significantly higher or tended to be higher with oxalic acid application. However, warming with oxalic acid application altered the partitioning of N between plants and soil microorganisms by increasing microbial 15N recovery to a lesser extent than it increased plant 15N recovery. While plants showed no specific preferences between N forms under normal conditions or warming alone, under warming and oxalic acid, plants showed a preference for 15NO3. Microorganisms showed a stronger preference for 15NH4 especially under warming and oxalic acid treatments. These findings suggest that plasticity in resource use could be an important mechanism in alleviating competition for soil N between plants and microbes under warming and oxalic acid addition.
    Print ISSN: 0045-5067
    Digitale ISSN: 1208-6037
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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    Good Co(o)p or Bad Co(o)p? Redistribution Concerns and Competition in Credit Markets with Imperfect Information (2021)
    De Gruyter
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    Publikationsdatum: 2021-02-22
    Beschreibung: Non-profit organizations (NPOs), such as financial cooperatives, have a longstanding tradition in advanced market economies. We develop a model of ‘mixed credit markets’ where pure for-profit institutions (e.g. commercial banks) can coexist with financial NPOs which feature a concern for inter-member surplus redistribution (e.g. credit cooperatives) and enjoy privileged borrower-specific information vis-à-vis their for-profit peers, while facing higher funding costs. We formally investigate market competition between the two alternative financial organizations both offering contracts whose terms entail cross subsidization. We argue that heterogeneity in organizational models can explain stable coexistence under competitive conditions, and also help us interpret the variety of market outcomes — in terms of e.g. overall coverage and market shares — as documented in modern financial systems. Importantly, the viability of redistribution-oriented NPOs is shown not to rest on under-investment issues or concerns about market power, for they can successfully operate in markets where credit rationing never arises.
    Digitale ISSN: 1935-1682
    Thema: Wirtschaftswissenschaften
    Publiziert von De Gruyter
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    Wheat straw and biochar effect on soil carbon fractions, enzyme activities, and nutrients in a tobacco field (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-02-18
    Beschreibung: Annual removal of tobacco residues and insufficient input of organic materials have exacerbated total organic carbon (TOC) depletion and soil degradation in a tobacco field in the Huanghuai area. Straw residue and biochar application may be effective ways to increase TOC accumulation and improve soil fertility. In this field experiment, wheat straw (WS) and wheat-straw derived biochar (BC) with mineral fertilizer were compared to mineral fertilizer alone (CK) and we assessed their effects on soil organic carbon fractions, enzyme activities, and nutrients in Shandong Province, China during 2016 and 2017. At 0–20 cm depth, the WS treatment had a greater overall effect on the measured soil properties. Compared with the control, the WS treatment significantly increased the concentrations of microbial biomass carbon (MBC), hot water-extractable carbon (HWC), and permanganate-oxidizable carbon concentrations (POXC; by 252.41%, 107.02%, and 65.53%, respectively); the activities of sucrase, urease, and phosphatase (by 112.52%, 7.81%, and 34.33%, respectively); and the contents of alkaline hydrolysable nitrogen, available phosphorus, and available potassium (by 92.22%, 100.78%, and 10.57%, respectively). Compared with the control, the BC treatment significantly increased TOC content, MBC content, light fraction organic carbon (LFOC) and potassium (TK) concentration (by 74.93%, 86.24%, 153.73%, and 21.92%, respectively). Most soil enzyme activity and nutrient parameters were significantly correlated with MBC. Thus, straw application improved soil fertility by increasing the concentrations of high labile organic carbon fractions (HWC, MBC, POXC), stimulating soil enzyme activities, and releasing more soil available nutrients, and BC addition contributed to the accumulation of TOC, MBC, LFOC, and TK.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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    Fall-applied cattle manure did not provide nitrogen fertilizer value to spring cereal crops (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-02-03
    Beschreibung: Fall-applied manure may have nitrogen (N) fertilizer value for spring-seeded crops. We applied liquid or solid cattle manure to plots on a sandy-loam soil in southern Quebec in fall. The following spring, half of each plot received urea fertilizer before planting the spring cereal crop. Total N content of the spring cereal at tillering, flowering, and maturity was lower in subplots without urea, and yields were up to 183% less in the no-urea subplots, regardless of whether liquid or solid manure was applied in fall. Fall-applied manure did not provide plant-available N to spring cereals under our growing conditions.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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  • 31
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    Lockdown Accounting (2021)
    De Gruyter
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    Publikationsdatum: 2021-02-09
    Beschreibung: We use an accounting framework to evaluate the aggregate impact of a common lockdown policy for 85 countries. We find that poorer countries devote more labor to essential activities that are unaffected by the lockdown, while richer countries can more easily substitute non-essential employment with work from home. The lockdown generates an employment response that is U-shaped in income: it drops by 32% in the poorest quintile of the distribution, by 36% in the middle quintile, and by 31% in the richest quintile. Annualized GDP declines by 39% in the bottom three quintiles and by 31% in the richest quintile. Agriculture, an essential sector, is key in sustaining employment and economic activity in poorer countries.
    Print ISSN: 2194-6116
    Digitale ISSN: 1935-1690
    Thema: Wirtschaftswissenschaften
    Publiziert von De Gruyter
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    Why do women become teachers while men don’t? (2021)
    De Gruyter
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    Publikationsdatum: 2021-01-22
    Beschreibung: Across countries, almost all primary and pre-primary teachers are women while few men in the occupation tend to specialise in secondary schooling and administration. We investigate the decision to become a teacher versus alternative occupations for graduates in Australia over the past 15 years. We find that this gender distribution reflects relative returns in the labour market: women with bachelor qualifications receive higher returns in teaching, while similarly educated men enjoy substantially higher returns in other occupations. We also find evidence that schools which can, and do, make higher wage offers successfully attract more male teachers as well as more female teachers with a degree in science, technology, engineering, and mathematics. These results are consistent with the predictions of theoretical models of self-selection of intrinsically motivated workers.
    Digitale ISSN: 1935-1682
    Thema: Wirtschaftswissenschaften
    Publiziert von De Gruyter
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    Reviewer acknowledgement Holzforschung volume 74 (2020) (2021)
    De Gruyter
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    Publikationsdatum: 2021-01-26
    Print ISSN: 0018-3830
    Digitale ISSN: 1437-434X
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von De Gruyter
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    Protecting Lives and Livelihoods with Early and Tight Lockdowns (2021)
    De Gruyter
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    Publikationsdatum: 2021-04-19
    Beschreibung: Using high-frequency proxies for economic activity over a large sample of countries, we show that the economic crisis during the first seven months of the COVID-19 pandemic was only partly due to government lockdowns. Economic activity also contracted severely because of voluntary social distancing in response to higher infections. Furthermore, we show that lockdowns substantially reduced COVID-19 cases, especially if they were introduced early in a country’s epidemic. This implies that, despite involving short-term economic costs, lockdowns may pave the way to a faster recovery by containing the spread of the virus and reducing voluntary social distancing. Finally, we document that lockdowns entail decreasing marginal economic costs but increasing marginal benefits in reducing infections. This suggests that tight short-lived lockdowns are preferable to mild prolonged measures.
    Print ISSN: 2194-6116
    Digitale ISSN: 1935-1690
    Thema: Wirtschaftswissenschaften
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  • 35
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    Frontmatter (2021)
    De Gruyter
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    Publikationsdatum: 2021-04-01
    Digitale ISSN: 1935-1682
    Thema: Wirtschaftswissenschaften
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    Soil Mehlich-3 extractable elements as affected by the addition of biochars to a clay soil co-amended with or without a compost (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-04-16
    Beschreibung: Biochar has potential to sequester carbon and mitigate greenhouse gas emissions, and it may also contribute nutrients for plant growth in temperate climates. Nutrient availability in biochar-amended soil was assessed in a 338-d incubation study. The clay soil prepared with 4% w/w (dry basis) compost or without compost, then amended with wood-based biochar made at different pyrolysis temperatures (maple bark [Acer saccharum] at 400°C [M400], 550°C [M550] and 700°C [M700]) on a dry-rate basis of 5% (w/w). After moistening the soil mixture to 44% volumetric soil water content (equivalent to 70% water-filled pore space), soil mixtures were incubated in the dark at 22°C. Soil was sampled at days 9, 16, 23, 44, 86, 23 170 and 338 of the incubation. Biochar amendment increased the Mehlich-3 P, K, Ca, Mg and Cu concentrations, and reduced the Mehlich-3 Al and Fe concentrations at each sampling date, and M400 had the most significant effect on Mehlich-3 extractable nutrient concentrations. Compost addition also increased the amounts of extractable nutrients. These results suggested that M400 and carbon-rich compost promoted microbial growth and mineralization in amended soil. In addition, soil mixed with compost and amended with biochar had more Mehlich-3 extractable K than when compost or biochar were applied alone, probably due to greater growth and activity of soil K-solubilizing microorganisms. Overall, our study indicated that co-application of wood-based biochar and compost could improve soil fertility in temperate regions by increasing the availability of most plant macronutrients and micronutrients.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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    Evaluation and modeling of factors influencing the depth of mixing layer in which soil solute releasing from soil to surface runoff (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-04-19
    Beschreibung: The depth of mixing layer is one of the important parameters which cannot be assigned a constant value affected by many factors in the slope runoff. The objective of this study was to investigate the effect of slope length and underground biomass on slope runoff, solute transport processes, as well as mixing layer depth. In this study, the experimental plots with the four slope lengths (5, 10, 15, and 20 m) and a width of 2 m were built on the slope with the gradient of 20°. In addition, the plots with the millet or wheat planting were built on the slope. The change of runoff and solute transport was analyzed through simulated rainfall experiments and then to estimate mixing layer depth. The results showed that the runoff rate decreased and more runoff seeped into the slope soil with increasing slope length. Increasing underground biomass also promoted greater rainfall infiltration into the soil. The increase in slope length increased the concentration of solute in runoff, but more underground biomass reduced the nutrients transported with runoff. The effective mixing depth increased with an increase in slope length, but effective mixing depth decreased with increased underground biomass. The modified expression of the equivalent mixing model under different slope lengths and underground biomass could accurately describe the solute transfer process in runoff when compared with complete mixing model and incomplete mixing model based on exponential functions. This research provided a reference for improving the application of mixing layer models in the slope management.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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    Understanding soil fertility status in Newfoundland from standard farm soil tests (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-04-14
    Beschreibung: Farm soil tests are common decision support tools employed by regulatory agencies and farmers to manage nutrients in an economical and environmentally sustainable way. The complex interplay between the local environment and locally relevant crops makes soil testing, and critically soil-test based recommendations, site-specific. Newfoundland and Labrador (NL) has a relatively small but rapidly growing commercial agriculture, mainly on lands converted from the boreal forest over the last 80 years. A first step towards developing locally calibrated fertilizer recommendations is understanding current practices. For this, we examined regular farm soil test reports and associated recommendations for Newfoundland (Nfld). Following a request distributed to 167 farmers, 1503 soil tests were obtained from 32 farms. While tests exemplify the gamut of crops in Nfld, more than half were from forage and mixed forage fields in western Nfld, representing dairy farms. Results show that even in the absence of more comprehensive site analyses, an investigative survey of farm tests may be employed to recognize possible environmental and economic inefficiencies of local cropping systems, including regional and crop type-driven differences, for both nitrogen (N) and phosphorus (P) fertilization. Soil-test based identification of possible N and/or P inefficiencies and associated crop and regional particularities, including excess fertilization, can be employed to devise targeted research for improved, preventative decision tools to increase the sustainability of Nfld agricultural systems.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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    SPATIAL DEPENDENCY OF SOIL CHEMICAL IN PRODUCTION SYSTEMS IN THE ANTHROPOGENIC DARK EARTH (2021)
    Canadian Science Publishing
    Details
    Publikationsdatum: 2021-04-15
    Beschreibung: Anthrosols refers to anthropic soils of high fertility in general, but the concentration of these nutrients may vary according to the occupation of indigenous people in the past or due to current soil use. This study aimed to evaluate the spatial variability of the chemical attributes of the soil in areas of guandu bean production and pasture and to compare with natural forest systems on Anthropogenic dark earth (ADE). For this assessment, 88 sampling points were selected in the area with natural forest vegetation and pasture and 90 sampling points in an area of guandu bean production. Soil samples were collected from layers 0.00-0.05, 0.05-0.10 and 0.10-0.20 m. Chemical analyses of the soil were conducted to determine organic matter, pH, Aluminium (Al3+), soil acidity (H+Al), phosphorus (P), potassium (K+), Calcium (Ca2+), Magnesium (Mg2+), cation exchange capacity (CEC), sum of bases (SB) and base saturation (V%). Data were analyzed using descriptive statistics and geostatistics to sample range, sample density was estimated for each attribute. Guandu bean showed high content of soil organic matter in relation to pasture in the superficial layer (0.00-0.05 m). Based on sample density, lower variability and higher spatial continuity were observed for guandu bean in relation to pasture and natural forest in the layers of 0.00-0.05 and 0.05-0.10 m. It was found that the use and continuous management of ADE’s areas alter the content and distribution of soil fertility and in some cases may even improve chemical attributes when compared to areas not used with agricultural crops.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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    Wood-based biochar for small fruit production in southern Quebec, Canada (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-04-15
    Beschreibung: The market for small fruits (grapes, blueberries, strawberries, and raspberries) is valued at more than CAD100 million per year in Quebec, Canada. Wood-based biochar is an amendment that improves soil quality, which may boost small fruit growth and production. The objective of this research was to determine if wood-based biochar could increase the yield and quality of grape, blueberry, strawberry, and raspberry in southern Quebec. We evaluated the fruit yield as well as the quality parameters like average fruit weight, fruit firmness, color, juice pH, total soluble solids, total phenolic content, and antioxidant activity. Field trials were established on commercial farms with grape, blueberry, strawberry, and raspberry production systems in plots that received wood-based biochar and no biochar in spring (April to May). Small fruits were harvested at their ripening stage for yield and quality evaluation in fall (July to October). Biochar application did not improve yield and quality parameters of small fruits except it gave a marginal higher yield of grape (3.7 vs. 4.4 t ha-1, P = 0.08) and a higher average fruit weight of strawberry (11.9 vs. 13.2 g, P 〈 0.05). There was no difference in the quality of the fruit from biochar-amended and control plots in the first year of biochar application, possibly because the quality parameters are affected more by weather conditions, handling, and storage than by soil quality. This work suggests that wood-based biochar (
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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  • 41
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    Nano-oxides immobilize Cd, Pb, and Zn in mine spoils and contaminated soils facilitating plant growth (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-04-26
    Beschreibung: Nanoparticles with high reactivity can be applied as amendments to remediate soil metal contaminations by immobilizing toxic elements. Nano-oxides of Fe have been studied but Al and Ti nano-oxides have not been tested for their remediation capacity of toxic metals. The potential of synthesized iron (Fe-O), aluminum (Al-O), and titanium (Ti-O) nano-oxides for stabilizing Cd, Pb, and Zn in mine spoil (Chat) and contaminated soil was compared using adsorption studies and a greenhouse experiment. Chat and soil were amended with nano oxides at two rates (25 and 50 g kg-1) and a pot experiment was conducted with sorghum (Sorghum bicolor L. Moench). Leachates were collected twice per week from plant emergence to harvest at maturity and metals were compared against an unamended control. Chat was contaminated with Cd, Pb, and Zn at 84, 1583, and 6154 mg kg-1, and soil at 15, 1260, and 3082 mg kg-1, respectively. Adsorption conformed to the Langmuir linear isotherm and adsorption maxima of metals were in the order of Al-O 〉 Ti-O ≥ Fe-O. Nano-oxides reduced Cd concentration by 28% (Fe-O) to 87% (Ti-O) and Zn concentration by 14% (Fe-O) to 85% (Al-O) in plant tissues compared with unamended Chat. Nano-oxides significantly reduced Cd, Pb, and Zn in leachates and available Cd and Zn in Chat/ soil relative to the respective unamended controls. Nano-oxides can be used to remediate heavy metal contaminated Chat and soil and facilitate plant growth under proper nutrient supplements. Nano-oxides of Al-O and Ti-O remediated metals more effectively than Fe-O
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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  • 42
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    Recycled Nutrients Supply Phosphorus and Improve Ryegrass Yields on Phosphorus Depleted Soil (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-04-26
    Beschreibung: Recycling phosphorus (P) within the food system is fundamental to long-term sustainability. This greenhouse study compared three sources of recycled P – struvite precipitated from municipal wastewater, black soldier fly frass from food waste, and anaerobic digestate of food waste – to mono-ammonium phosphate (MAP), compost, and a control. Italian Ryegrass (Lolium multiflorum) was harvested four times during a 123 day trial from a P-depleted soil. In nitrogen (N) sufficient conditions, all amendments significantly increased cumulative ryegrass yields compared to the control, and were not significantly different from MAP. Relative P supply was frass=MAP〉struvite〉= compost〉=digestate〉〉control. The recycled nutrient sources tested show promise as sustainable P sources.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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  • 43
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    Productivity of coastal Douglas-fir and western redcedar in response to species mixture, planting density, and soil carbon:nitrogen ratio (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-04-27
    Beschreibung: Mixed-species plantations have been suggested as ecologically and economically viable alternatives to monocultures. We examined the growth response of coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) and western redcedar (Thuja plicata Donn ex D. Don in Lamb.) to different species mixtures (Douglas-fir : western redcedar mixtures of 1:0, 1:1, 1:3, and 0:1) and planting densities (500, 1000, and 1500 stems·ha−1) in a dry maritime forest on eastern Vancouver Island, Canada. Twenty-two years postplanting, species mixture significantly affected diameter and height growth (p 〈 0.001), with stand diameter and height generally decreasing with increasing redcedar composition. Inherent variation in soil productivity across the plantation (carbon:nitrogen ratio) equally constrained stand growth. The widest spacing had larger diameter than the closest spacing (p = 0.025) but the least stand basal area compared with the other spacing treatments (p = 0.003–0.031). Stand volume was significantly affected by mixture × density interaction (p = 0.024) and generally declined with increasing proportion of redcedar and decreasing stand density. In the first decades after plantation establishment, inherent species growth traits and soil fertility were most important in dictating stand productivity. Because of the differences in resource utilization of both species, stand dynamics may change as competition for light and soil resources increases. Evaluation of silvicultural recommendations regarding mixtures of both species will continue with plantation development.
    Print ISSN: 0045-5067
    Digitale ISSN: 1208-6037
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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    Frontmatter (2021)
    De Gruyter
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    Publikationsdatum: 2021-04-01
    Print ISSN: 1081-1826
    Digitale ISSN: 1558-3708
    Thema: Mathematik , Wirtschaftswissenschaften
    Publiziert von De Gruyter
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  • 45
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    Frontmatter (2021)
    De Gruyter
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    Publikationsdatum: 2021-02-01
    Print ISSN: 1081-1826
    Digitale ISSN: 1558-3708
    Thema: Mathematik , Wirtschaftswissenschaften
    Publiziert von De Gruyter
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  • 46
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    Note of appreciation / Note de reconnaissance (2021)
    Canadian Science Publishing
    Details
    Publikationsdatum: 2021-03-01
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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  • 47
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    Adaptation and Loss Aversion in the Relationship Between GDP and Subjective Well-Being (2021)
    De Gruyter
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    Publikationsdatum: 2021-03-22
    Beschreibung: We examine the roles of macro-level adaptation — including social comparison effects becoming more important over time — and macroeconomic loss aversion in the time-series relationship between national income and subjective well-being. Models allowing for these phenomena are applied to cross-country panel data. We find evidence for macroeconomic loss aversion that becomes more important over time: the effects of economic growth become small and statistically insignificant in the long run, whereas the effects of contractions are large and long-lasting. The results are consistent with the Easterlin paradox and point to it being explained by macro-level adaptation to economic growth. Our results highlight the importance of allowing for both dynamics to distinguish long-run from short-run effects and asymmetries to recognize the important effects of contractions. Failing to do the former leads to a misleading impression of the long-run relationship between economic growth and well-being.
    Digitale ISSN: 1935-1682
    Thema: Wirtschaftswissenschaften
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  • 48
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    Skepticism and Credulity: A Model and Applications to Political Spin, Belief Formation, and Decision Weights (2021)
    De Gruyter
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    Publikationsdatum: 2021-03-19
    Beschreibung: In this paper I model a decision maker who forms beliefs and opinions using a dialectic heuristic that depends on their degree of skepticism or credulity. In an application to political spin, two competing parties choose how to frame commonly observed evidence. If the receiver is sufficiently credulous, equilibrium spin is maximally extreme and generates short, superficial news cycles. When receivers vary in their skepticism, there is partisan sorting by skepticism parameter: the more credulous group systematically favors one party and displays hostility to evidence and a media they see as biased. In behavioral applications in which the frames arise from the decision maker’s internal deliberation, a decision maker with the same credulous nature would display known behavioral anomalies in forming beliefs and forming decision weights from stated probabilities. The dialectic model therefore captures a simple psychological mechanism and matches closely some stylized facts across these three disparate applications.
    Print ISSN: 2194-6124
    Digitale ISSN: 1935-1704
    Thema: Wirtschaftswissenschaften
    Publiziert von De Gruyter
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  • 49
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    Reactivity of a benzylic lignin-carbohydrate model compound during enzymatic dehydrogenative polymerisation of coniferyl alcohol (2021)
    De Gruyter
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    Publikationsdatum: 2021-01-27
    Beschreibung: Lignin is thought to be covalently bound to carbohydrates like hemicellulose during biosynthesis to form a lignin-carbohydrate complex (LCC). However, successive polymerisation with monolignols after the formation of LCC has not yet been clarified. To investigate the reaction of LCC, its enzymatic dehydrogenative polymerisation was conducted using deuterium-labelled coniferyl alcohol and model compounds, i.e., a lignin model (β-O-4 dimer model) compound (LM) and an LCC model (benzyl ether type) compound (LCCM). The obtained polymers (DHPs) were methylated and subjected to thioacidolysis, and the degradation products were quantified by gas chromatography-mass spectrometry (GC-MS). The results showed that the amount of coniferyl alcohol connected to the LCCM via β-O-4 binding was almost the same as that bound to the LM. However, the amount of unreacted LCCM was larger than that of LM, suggesting that the LCCM is less likely to form condensed structures, i.e., 5-5, β-5, and 4-O-5 structures. This could be due to the steric hindrance of the carbohydrate at the benzylic position.
    Print ISSN: 0018-3830
    Digitale ISSN: 1437-434X
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von De Gruyter
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  • 50
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    Fifty years of forest science (2021)
    Canadian Science Publishing
    Details
    Publikationsdatum: 2021-02-01
    Print ISSN: 0045-5067
    Digitale ISSN: 1208-6037
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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  • 51
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    Estimating rill erosion and sediment transport processes along a saturated purple soil slope (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-04-14
    Beschreibung: A plough pan with reduced permeability always accumulates infiltrated water along slopes then saturates the cultivated layer under continuous rain. Topsoil saturation is a frequent phenomenon and an important process of the special soil slopes. A methodology and device system was used in this study to keep cultivated purple soil saturated. Strands of scouring tests were developed to quantify the rill erosion and sediment transport processes along a saturated purple soil slope at four experiment slopes (5°, 10°, 15°, and 20°) and three flow discharges (2, 4 and 8 L min−1). The experimental results indicated that the sediment transport capacity on a saturated purple soil slope ranged from 0.03 to 1.56 kg s−1 m−1 with the increasing trend along the slope gradient and flow discharge, and the increasing trend could be well matched by a nonlinear multivariable equation. The sediment concentration of the saturated purple soil slope exponentially increased with rill length and decreased with the increment rate and the maximum sediment concentrations observed in this study in different hydraulic events ranged from 108.13 to 1174.20 kg m-3. Saturated and non-saturated purple soil slopes erode differently with the maximum sediment concentration of saturated purple soil slope recorded at approximately 1.42-2.10 times the values for non-saturated purple soil slope. The findings of this research help illustrate the sediment transportation and erosion behaviors of a saturated purple soil slope, and serve as the basis for determining the parameters in the erosion models of the purple soil slope.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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  • 52
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    Effects of mulching with crushed wheat straw padding and plastic film on sunflower emergence, yield, and yield components under different irrigation intensity in the northwest arid regions, China (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-04-08
    Beschreibung: Crops in the northwest arid region of China frequently suffer from low emergence and poor yield due to high water deficit. Mulching is an important approach to reduce irrigation amount while increasing productivity but faces challenge of ecological adaptability in this region. A field experiment was carried out in the three growing seasons from 2011 to 2013 to study effects of mulching with crushed wheat straw padding and plastic film on sunflower seed emergence and yields under different irrigation intensities. A two factor (mulching, irrigation intensity) completely randomized block design was applied, resulting in a total of 12 treatments repeated three times. Mulching treatments includes: zero mulch (N), straw mulching at the beginning of trial (S), plastic film mulching when sowing (F), a commonly used mulching by local farmers, and double mulching with plastic film on the crushed wheat straw layer (SF). Irrigation intensity includes: High (H=900 m3 ha-1), Medium (M=750m3 ha-1), Low (L=600m3 ha-1). Results showed that all mulching treatments promoted early emergence of seedlings compared with N, with SF and F performing the better than the rest. SF was the best-performing mulching approach in this study, and had significantly improved sunflower yield and yield components compared with other treatments. In SF, medium irrigation level had significantly increased sunflower 100-seed weight. Therefore, SF with medium irrigation level showed the most positive effect on sunflower production and in now the recommended agronomic solution for sunflower production in the northwest arid regions and potentially, other irrigated areas with similar ecological conditions.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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  • 53
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    Root physiological responses can explain the effects of short-term plant-plant interactions on growth of two subalpine coniferous species (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-04-13
    Beschreibung: Root functional traits play an important role in nutrient acquisition of plants, affecting the outcome of plant-plant interactions. However, few studies have comprehensively investigated the plastic responses of plant root traits to plant-plant interactions. A pot experiment was conducted to quantify the effects of intraspecific and interspecific interactions on seedlings growth and multiple root traits of two coniferous species, Picea asperata and Abies faxoniana. The results showed that plant-plant interactions changed root physiology of two species but did not affect their root system, morphological, architectural and biotic traits. Intraspecific interaction resulted in lower root N content and stronger resource competition than under interspecific interaction. Under intraspecific interaction, P. asperata had lower root vigor and nitrate reductase activity, which impeded the acquisition and utilization of the limited resources, and thus resulted in marginally decreased total biomass; while total biomass for A. faxoniana was not significantly affected. Under interspecific interaction, the high total biomass of A. faxoniana could be explained by rhizosphere interactive effects and reduced metabolic (carbon and nitrogen) costs due to lower root exudative outputs. Our results demonstrate that root physiological responses can explain the effects of short-term plant-plant interactions on plant growth.
    Print ISSN: 0045-5067
    Digitale ISSN: 1208-6037
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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  • 54
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    LEAF LITTER DYNAMICS IN WESTERN BLACK SEA MOUNTAINOUS FOREST ECOSYSTEMS (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-04-13
    Beschreibung: This study aimed to estimate leaf litter decomposition rates in eastern beech (Fagus orientalis Lipsky) and sweet chestnut (Castanea sativa Mill.) mixed stands in Düzce-Akçakoca, located in the Western Black Sea Region of Turkey. The sampling areas represent four different elevations and two aspects at each elevation. Amounts of annual beech and chestnut litter fall were estimated as 5.19 Mg ha-1 and 4.61 Mg ha-1, respectively. Litter decomposition was examined over five time periods (0.25, 0.50, 1.25, 2.25, and 4.25 years) by using the litter bag method. The amount of remaining beech leaf litter mass was found to be 1.1, 1.2, 1.2, 1.4, and 1.3 times greater than the amount of chestnut leaf litter, respectively. However, estimated values for the decomposition rate-constant (k) of chestnut for all time periods were found to be approximately 1.5 times greater than those of beech leaf litter. Litter in beech stands decomposed more rapidly at higher elevations during the first year, but at lower elevations in the second year, likely due to increased temperature and precipitation for the corresponding years. Leaf litter in chestnut stands decomposed more rapidly at lower elevations in the second and fourth year, reflecting higher precipitation of those years.
    Print ISSN: 0045-5067
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    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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  • 55
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    Knowledge, Awareness and Probabilistic Beliefs (2021)
    De Gruyter
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    Publikationsdatum: 2021-02-17
    Beschreibung: Bayesian game theory investigates strategic interaction of players with full awareness but incomplete information about their environment. We extend the analysis to players with incomplete awareness, who might not be able to reason about all contingencies in the first place. We develop three logical systems for knowledge, probabilistic beliefs and awareness, and characterize their axiom systems. Bayesian equilibrium is extended to games with incomplete awareness and we show that it is consistent with common prior and speculative trade, when common knowledge of rationality is violated.
    Print ISSN: 2194-6124
    Digitale ISSN: 1935-1704
    Thema: Wirtschaftswissenschaften
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    Are There Peer Effects from English Learners in Elementary Schools? Evidence from an IV Approach (2021)
    De Gruyter
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    Publikationsdatum: 2021-02-19
    Beschreibung: We study the peer effects of English Learners on the test scores of native English speaking students using a new instrument to account for the endogeneity of students’ English Learner status. Relative to what OLS estimates would suggest, we find smaller and insignificant peer effects of English Learners on native English speaking students in California elementary schools.
    Digitale ISSN: 1935-1682
    Thema: Wirtschaftswissenschaften
    Publiziert von De Gruyter
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    Agricultural Trade and Structural Change: Evidence from Paraguay (2021)
    De Gruyter
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    Publikationsdatum: 2021-02-17
    Beschreibung: We study how international trade affects structural change in an agricultural exporting country. For this purpose, we calibrate a three-sector growth model to quantify the role of international trade in explaining structural change patterns observed in Paraguay. This country experienced a significant rise in net agricultural exports as a percentage of aggregate output during the period 1962–2012. We find the following results. First, international trade is crucial to explain the sectoral composition of employment in this country. The model including trade explains 84.2% of observed changes in employment shares during this period, while the model without trade can only account for 35.6% of observed changes. Second, employment in agriculture remains large in order to satisfy foreign demand. Third, employment shifts directly from agriculture into services in the long run, bypassing manufacturing. These patterns can only be explained by the rise in net agricultural exports.
    Print ISSN: 2194-6116
    Digitale ISSN: 1935-1690
    Thema: Wirtschaftswissenschaften
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    Unraveling News: Reconciling Conflicting Evidence (2021)
    De Gruyter
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    Publikationsdatum: 2021-02-19
    Beschreibung: This paper addresses the lack of consensus in the empirical literature regarding the effects of technology diffusion news shocks. We attribute the conflicting evidence to the wide diversity in terms of variable settings, productivity series used, and identification schemes applied. We analyze the different identification schemes that have been employed in this literature. More specifically, we impose short- and medium-run restrictions to identify a news shock. The focus is on the medium-run identification maximizing at and over different horizons. We show that the identified news shock depends critically on the applied identification scheme and on the maximization horizon. We also investigate the importance of the information content of the model and of the productivity measure used. We find that models which either contain a large set of macroeconomic variables or include variables that are strongly forward looking deliver more robust results. Moreover, we show that the productivity series used may influence results, but there is convergence of findings for newer total factor productivity series vintages. Our conclusion is that news shocks have expansionary properties.
    Print ISSN: 2194-6116
    Digitale ISSN: 1935-1690
    Thema: Wirtschaftswissenschaften
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    Time-varying threshold cointegration with an application to the Fisher hypothesis (2021)
    De Gruyter
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    Publikationsdatum: 2021-02-22
    Beschreibung: This paper extends the threshold cointegration model developed by Gonzalo, J., and J. Y. Pitarakis. 2006. “Threshold Effects in Cointegrating Relationships.” Oxford Bulletin of Economics & Statistics 68: 813–33 and Chen, H. 2015. “Robust Estimation and Inference for Threshold Models with Integrated Regressors.” Econometric Theory 31 (4): 778–810 to allow for a time-varying threshold, which is a function of candidate variables that affect the separation of regimes. We derive the asymptotic distribution of the proposed least-square estimator of the threshold, and study the convergence rate of the threshold estimator. We also suggest test statistics for threshold effect and threshold constancy. Monte Carlo simulations point out that the convergence rate of the threshold estimator is consistent with the asymptotic theory, and the proposed tests have good size and power properties. The empirical usefulness of the proposed model is illustrated by an application to the US data to investigate the Fisher hypothesis.
    Print ISSN: 1081-1826
    Digitale ISSN: 1558-3708
    Thema: Mathematik , Wirtschaftswissenschaften
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    Climate-based Allometric Biomass Equations for Five Major Canadian Timber Species (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-04-20
    Beschreibung: Accurate estimation of forest biomass is essential to quantify the role forests play at balancing terrestrial carbon. Allometric equations based on tree size have been used for this purpose worldwide. There is little quantitative understanding on how environmental variation may affect tree allometries. Even less known is how to incorporate environmental factors into such equations to improve estimation. Here we tested the effects of climate on tree allometric equations and proposed to model forest biomass by explicitly incorporating climatic factors. Among the five major Canadian timber species tested, the incorporation of climate was not found to improve the allometric models. For trembling aspen and tamarack, the residuals of their conventional allometric models were found strongly related to frost-free period and mean annual temperature, respectively. The predictions of the two best climate-based models were significantly improved, which indicate that trembling aspen and tamarack store more aboveground biomass when growing in warmer than in colder regions. We showed that, under the RCP4.5 modest climate change scenario, there would be a 10% underestimation of aboveground biomass for these two species if the conventional non-climate models would still be in use in 2030. This study suggests the necessity to proactively develop climate-based allometric equations for more accurate and reliable forest biomass estimation.
    Print ISSN: 0045-5067
    Digitale ISSN: 1208-6037
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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    Multivariate Markov-switching score-driven models: an application to the global crude oil market (2021)
    De Gruyter
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    Publikationsdatum: 2021-04-28
    Beschreibung: A new class of multivariate nonlinear quasi-vector autoregressive (QVAR) models is introduced. It is a Markov switching score-driven model with stochastic seasonality for the multivariate t-distribution (MS-Seasonal-t-QVAR). As an extension, we allow for the possibility of having common-trends and nonlinear co-integration. Score-driven nonlinear updates of local level and seasonality are used, which are robust to outliers within each regime. We show that VAR integrated moving average (VARIMA) type filters are special cases of QVAR filters. Using exclusion, sign, and elasticity identification restrictions in MS-Seasonal-t-QVAR with common-trends, we provide short-run and long-run impulse response functions for the global crude oil market.
    Print ISSN: 1081-1826
    Digitale ISSN: 1558-3708
    Thema: Mathematik , Wirtschaftswissenschaften
    Publiziert von De Gruyter
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    Racial Disparity in COVID-19 Deaths: Seeking Economic Roots with Census Data (2021)
    De Gruyter
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    Publikationsdatum: 2021-04-30
    Beschreibung: This note seeks the socio-economic roots of racial disparities in COVID-19 mortality, using monthly county-level mortality, economic, and demographic data from 3140 counties through December 2020. The county-level approach shows a sharp disparity affecting all minority groups in the sample, peaking in spring or summer 2020 and then dissipating by the end of autumn. The effect disappears for Asian Americans when occupation and other controls are added, but not for other minorities; for them, the racial disparity, as long as it lasts, does not seem to be due to differences in income, poverty rates, education, occupational mix, or even access to healthcare insurance, although in April public transit use explains a large part of it. This is a puzzle, but the rapid change in the disparities over the year show that they are not immutable – an important message for future pandemics.
    Digitale ISSN: 1935-1682
    Thema: Wirtschaftswissenschaften
    Publiziert von De Gruyter
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    Frontmatter (2021)
    De Gruyter
    Details
    Publikationsdatum: 2021-04-29
    Print ISSN: 0018-3830
    Digitale ISSN: 1437-434X
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von De Gruyter
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    Home Production and Leisure during the COVID-19 Recession (2021)
    De Gruyter
    Details
    Publikationsdatum: 2021-04-26
    Beschreibung: Between the months of February and April of 2020, average weekly market hours in the U.S. dropped by 6.25, meanwhile 36% of workers reported switching to remote work arrangements. In this paper, we examine implications of these changes for the time allocation of different households, and on aggregate. We estimate that home production activity increased by 2.65 h a week, or 42.4% of lost market hours, due to the drop in market work and rise in remote work. The monthly value of home production increased by $39.65 billion – that is 13.55% of the concurrent $292.61 billion drop in monthly GDP. Although market hours declined the most for single, less educated individuals, the lost market hours were absorbed into home production the most by married individuals with children. Adding on the impact of school closures, our estimate of weekly home production hours increases by as much as 4.92 h. The increase in the value of monthly home production between February and April updates to $73.57 billion. We also report the estimated impact of labor markets and telecommuting on home production for each month in 2020.
    Print ISSN: 2194-6116
    Digitale ISSN: 1935-1690
    Thema: Wirtschaftswissenschaften
    Publiziert von De Gruyter
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  • 65
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    Multiple structural breaks in cointegrating regressions: a model selection approach (2021)
    De Gruyter
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    Publikationsdatum: 2021-04-09
    Beschreibung: In this paper, we propose a new approach to model structural change in cointegrating regressions using penalized regression techniques. First, we consider a setting with known breakpoint candidates and show that a modified adaptive lasso estimator can consistently estimate structural breaks in the intercept and slope coefficient of a cointegrating regression. Second, we extend our approach to a diverging number of breakpoint candidates and provide simulation evidence that timing and magnitude of structural breaks are consistently estimated. Third, we use the adaptive lasso estimation to design new tests for cointegration in the presence of multiple structural breaks, derive the asymptotic distribution of our test statistics and show that the proposed tests have power against the null of no cointegration. Finally, we use our new methodology to study the effects of structural breaks on the long-run PPP relationship.
    Print ISSN: 1081-1826
    Digitale ISSN: 1558-3708
    Thema: Mathematik , Wirtschaftswissenschaften
    Publiziert von De Gruyter
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    The Neoclassical Growth Model and the Labor Share Decline (2021)
    De Gruyter
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    Publikationsdatum: 2021-04-12
    Beschreibung: The labor share may be declining in the data, but it is often assumed constant in neoclassical growth models (NGM). We assess the quantitative importance of this discrepancy by comparing alternative calibration approaches featuring constant and declining labor shares. We find little difference in model performance. Our results derive from strong general equilibrium effects: while a declining labor share mechanically lowers wage growth, the investment response pushes wages back up. Hence, different models deliver nearly identical paths of macro aggregates. Numerous robustness checks (including a CES production function, different time periods, and calculations of the labor share) reinforce the similarity of performance across model specifications. We conclude that the NGM with a constant labor share is still an appropriate choice to study many standard macro aggregates.
    Print ISSN: 2194-6116
    Digitale ISSN: 1935-1690
    Thema: Wirtschaftswissenschaften
    Publiziert von De Gruyter
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    International Historical Evidence on Money Growth and Inflation: The Role of High Inflation Episodes (2021)
    De Gruyter
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    Publikationsdatum: 2021-04-09
    Beschreibung: How long is the long run in the relationship between money growth and inflation? How important are high inflation episodes for the unit slope finding in the quantity theory of money? To answer these questions, we study the relationship between excess money growth and inflation over time and across frequencies using annual data from 1870 to 2013 for 16 developed countries. Wavelet-based exploratory analysis shows the existence of a close stable relationship between excess money growth and inflation only over long time horizons, i.e. periods greater than 16–24 years, with money growth mostly leading. When we investigate the sensitivity of the unit slope finding to inflation episodes using a “time-frequency-based” panel data approach, we find that low-frequency regression coefficients estimated over variable-length subsamples are largely affected by high inflation episodes occurring in the 1910s, the 1940s, and the 1970s. Taken together, our results suggest that inflationary upsurges affect regression coefficients, but not the closeness of the long-run relationship. This reconciles the validity of the quantity theory of money with the current disinterest of monetary policymaking in money growth.
    Print ISSN: 2194-6116
    Digitale ISSN: 1935-1690
    Thema: Wirtschaftswissenschaften
    Publiziert von De Gruyter
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  • 68
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    The non-linear effects of the Fed asset purchases (2021)
    De Gruyter
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    Publikationsdatum: 2021-04-02
    Beschreibung: The Federal Reserve responded to the great financial crisis deploying new monetary policy tools, the most notable of which being the expansion of its balance sheet. In a recent paper, Weale, M., and T. Wieladek. 2016. “What Are the Macroeconomic Effects of Asset Purchases?” Journal of Monetary Economics 79 (C): 81–93 show that the asset purchases were effective in stimulating economic activity as well as inflation and asset prices. Here I show that their results are state dependent: large scale asset purchase are effective only when financial markets are impaired. Financial markets are under stress when the effective risk-bearing capacity of the financial sector is drastically reduced, i.e. when the excess bond premium (EBP) of Gilchrist, S., and E. Zakrajšek. 2012. “Credit Spreads and Business Cycle Fluctuations.” The American Economic Review 102 (4): 1692–72 exceed a certain threshold. Using an estimated threshold vector autoregressive model conditional on the EBP regime, I show that an increase in the balance sheet has expansionary effects on GDP and inflation when EBP is high, but not when it is low (as its effects become mostly insignificant). I argue that the high EBP can be interpreted as a proxy of market dis-functioning so that only when this channel of transmission is on, the unconventional policy is particularly effective. This suggests that models of transmission of unconventional policies, based on asset purchases, should focus also on the market functioning channel and not only on the portfolio balance one.
    Print ISSN: 1081-1826
    Digitale ISSN: 1558-3708
    Thema: Mathematik , Wirtschaftswissenschaften
    Publiziert von De Gruyter
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    Combining perennial grass–legume forages and liquid dairy manure contributes to nitrogen accumulation in a clayey soil (2021)
    Canadian Science Publishing
    Details
    Publikationsdatum: 2021-03-04
    Beschreibung: Repeated applications of liquid dairy manure (LDM) and perennial crops generally favor nitrogen (N) stocks in soils, but in ways that may differ with soil type and other management practices. The objective of this study was to assess the long-term (21 yr) changes in soil N stocks (0–50 cm) of a silty clay soil, in a cool humid climate, in response to mineral fertilization (MIN) or LDM, combined with two tillage practices [chisel plow (CP), or moldboard plow (MP)], and two crop rotations [cereal monoculture (monoculture) or cereal–perennial forage rotation (forage-based rotation)]. The forage-based rotation favoured a greater accumulation of N in the first 20 cm of soil (+50 kg N·ha−1·yr−1) when compared with the monoculture. Tillage practices did not impact N stocks in the whole soil profile, but influenced its vertical distribution, with greater accumulation at the surface with CP, and at depth with MP. Annual input of LDM increased N stocks at the surface (0–20 cm) compared with MIN, especially when combined with the forage-based rotation. After 21 yr, soil N stocks (0–50 cm) with LDM were 32% (+2 t N·ha−1) higher in the forage-based rotation than in the monoculture, suggesting better retention and more efficient use of manure-N with perennial forages than cereals. Comparisons between the N mass balance computed for each cropping system, and the changes in soil N stocks indicated that accumulation of N under the forage-based rotation was largely due to symbiotic fixation by legumes in the forage mixture.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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  • 70
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    Conflicting portrayals of remaining old growth: the British Columbia case (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-04-05
    Beschreibung: Old growth is disappearing globally with implications for biodiversity, forest resilience and carbon storage; yet uncertainty remains about how much exists, partly because assessments stratify ecosystems differently, sometimes obscuring relevant patterns. This paper compares portrayals of BC’s old growth forest stratified in two ways: by biogeoclimatic variant, as per policy, and by relative site productivity. Our analyses confirm provincial government claims that about a quarter of BC’s forests are old growth, but find that most of this area has low realized productivity, including subalpine and bog forests, and that less than 1% is highly productive old growth, growing large trees. Within biogeoclimatic variant, nearly half of high productivity forest landscapes have less than 1% of the expected area of old forest. Low productivity ecosystems are over-represented in protected forest. We suggest that the experiment of managing old growth solely by biogeoclimatic variant has failed, and that current forest policy, in combination with timber harvesting priorities, does not maintain representative ecosystems, counter to the intent of both policy and international conventions. Stratifying old growth by relative productivity within biogeoclimatic variant seems an appropriate method to portray ecosystem representation, potentially increasing the probability of maintaining ecosystem resilience.
    Print ISSN: 0045-5067
    Digitale ISSN: 1208-6037
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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    Competitively-Issued Convertible Bank Notes in a Theory of Finance: Earl Thompson Meets Fischer Black (2021)
    De Gruyter
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    Publikationsdatum: 2021-04-02
    Beschreibung: In this paper, I show the validity of and the relationship between two previously unrelated claims in monetary theory. The first claim, made by Earl Thompson, is that privately-issued bank notes pay a positive rate of return in a competitive equilibrium. The second claim, made by Fischer Black, is that it is possible to have a gold standard in which the gold reserves of the central bank are near zero. I show that both of these claims are correct under the assumption of complete markets and perfect commitment. The link between these claims is the Black-Scholes equation applied to convertible bank notes. In commodity-based monetary systems, bank notes are perpetual American options. I extend the model to consider the implications of a lack of commitment on the part of the bank and incomplete markets. I show that both arguments break down when banks lack commitment to redemption or markets are incomplete. I conclude with implications for macroeconomic theory.
    Print ISSN: 2194-6124
    Digitale ISSN: 1935-1704
    Thema: Wirtschaftswissenschaften
    Publiziert von De Gruyter
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    Media Capture and Bias in the Market for News (2021)
    De Gruyter
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    Publikationsdatum: 2021-04-08
    Beschreibung: We analyze a model of media bias under government capture and a free press. The government wants citizens to invest in a project. Citizens gain from investing only if the state of the economy is good. The state is unobserved. The media firm receives a noisy signal about the actual state and makes a report about whether or not the state of the economy is good. Citizens read the report and decide whether or not to invest. In this context, we show that media bias under government capture may be smaller (greater) than that under free press if the cost of investment is sufficiently high (low) provided that the signal noise is below a certain threshold. Finally, we show that the difference between the bias under government capture and free press diverges (converges) when the cost of investment is sufficiently high (low) in response to a reduction in noise.
    Digitale ISSN: 1935-1682
    Thema: Wirtschaftswissenschaften
    Publiziert von De Gruyter
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    Frontmatter (2021)
    De Gruyter
    Details
    Publikationsdatum: 2021-04-01
    Print ISSN: 0018-3830
    Digitale ISSN: 1437-434X
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von De Gruyter
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    “Prescribed fire shrub consumption in a Sierra Nevada mixed-conifer forest (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-04-13
    Beschreibung: Live shrubs in forest understories pose a challenge for mitigating wildfire risk with prescribed fire. Factors driving shrub consumption in prescribed fires are variable and difficult to explain. This study investigated spatial patterns and drivers of Sierra Nevada mixed-conifer forest shrub consumption in prescribed fires through analysis of high-resolution imagery taken before and after prescribed fire. We applied a spatially explicit, generalized additive model to assess tree cover and coarse woody material as potential drivers of shrub consumption. Shrub cover in two experimental stands prior to burning was 38% and 59% and was 36% and 45% one-year post burn. In both stands shrub patch density increased, while area-weighted mean patch size and largest patch index decreased. Increased local percent cover of coarse woody material was associated with increased shrub consumption. These findings provide information for prescribed fire managers to help better anticipate shrub consumption and patchiness outcomes under similar conditions.
    Print ISSN: 0045-5067
    Digitale ISSN: 1208-6037
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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    Dating Structural Changes in UK Monetary Policy (2021)
    De Gruyter
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    Publikationsdatum: 2021-04-12
    Beschreibung: The UK historical monetary policy experience is rich of institutional changes, but it remains unclear which of these many events dominated the policy actions and what timing characterised the inception of different policy regimes. We develop a new empirical approach to answer these questions and we identify in particular the historical institutional events that effectively translated into a shift of the systematic actions of the UK monetary authorities. We find that not all institutional events triggered a contemporaneous change in the actual policy conduct, although a coherent evolution in phases is evident since 1978, when a significant monetary policy rule emerges. These occasional but not sporadic regime changes explain a considerable share of the movements in the official interest rate, as well as an overstatement of the importance of policy inertia.
    Print ISSN: 2194-6116
    Digitale ISSN: 1935-1690
    Thema: Wirtschaftswissenschaften
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    Effects of induced water deficit and biofertilization on growth dynamics and bulb yield of onion (Allium cepa L.) in a neotropical semi-arid environment (2021)
    Canadian Science Publishing
    Details
    Publikationsdatum: 2021-04-08
    Beschreibung: In a scenario of world population increase and climate change, an efficient use of water is key for agricultural production. Onion is one of the most profitable crops and can adapt to particular conditions of water stress. The objective of this research was to determine growing degree-days (GDD) and accumulated radiation under non-stress conditions, and yield of an F1 2000 hybrid of onion (Allium cepa L.) under water deficit and biofertilization in a semi-arid environment. An established nutrient requirement of 247 kg N, 240 kg P2O5 (105 kg P), 240 kg K2O (199 kg K) and two irrigation factors were applied: normal irrigation (NI) with a daily and water deficit (WD) with a three-day interval irrigation frequencies. The effect of biofertilization was evaluated through the inoculation of a microbial consortium in combination with four NPK fertilizer treatments. The crop accumulated 1334 °Cd and 1188 MJ m-2 d-1 at the time of harvest at 71 days after transplanting (DAT). The yield was 36 t ha-1, similar under both irrigation conditions; and the WD treatment resulted in a 35% water savings, a 47% and 65% increase in water use efficiency (WUE) and modulus of elasticity, respectively. The microbial consortium resulted in a 50% NPK savings under non-limiting water conditions and produced a similar yield compared to the 100% NPK non-inoculated control. The lower irrigation frequency together with the 100% NPK fertilization dose without the microbial consortium, and the use of the microorganisms and the 50% NPK treatment without water stress are recommended as agrosustainable practices for onion production.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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    Accumulation of straw derived carbon, and changes in soil humic acid structural characteristics during corn straw decomposition (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-04-08
    Beschreibung: Appropriate application of corn straw residues increase soil organic carbon (SOC) sequestration. Yet, sequestration and stabilization of added carbon (C) during corn straw transformation is not fully understood. Here, we present changes in soil humus C and humic acid (HA) molecular structure during corn straw decomposition in an incubation experiment carried out for 270 days at 25 °C. Corn straw was applied at the amount of 74.76 g per 18 kg soil (i.e., 1.57 g C kg-1), in the soil surface (CS1), incorporated within 0–10 cm (CS2), applied below 10 cm soil depth (CS3), and no corn straw applied. The results showed that after corn straw application (CS1, CS2 and CS3), accumulation of SOC content was rapid in the first 90 days. The HA spectral results of straw amended soils showed a slight increase in aliphatic C compounds and amino acids in day 90. In day 180, the degree of condensation was less, and aliphatic C compounds were present in large quantities in soil HA. As decomposition advanced to day 270, the aliphatic character of HA appeared to slightly weaken, and soil HA was enriched with aromatic structures. These results suggest that corn straw application enrich soil HA with more aliphatic C compounds in the early stages of decomposition, and aromatic C structures are formed in the later stage of decomposition. Incorporation of corn straw into the soil (CS2 treatment) is more conducive in increasing SOC and aliphaticity in HA during corn straw decomposition, which can potentially increase C sequestration.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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    Political Budget Cycle, Tax Collection, and Yardstick Competition (2021)
    De Gruyter
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    Publikationsdatum: 2021-03-08
    Beschreibung: This paper exploits the political cycle of Italian municipalities to test for the presence of strategic interactions in the collection of local taxation. The revenue from the personal income tax surcharge—a tax tool of low salience—is (positively) plagued by political manipulation and is found to be a strategic complement, but only when mayors run for re-election, a finding consistent with the yardstick competition hypothesis. More salient fiscal tools, such as property tax and user fees and charges, are also (negatively) affected by budget cycles, but they do not appear to be spatially correlated.
    Digitale ISSN: 1935-1682
    Thema: Wirtschaftswissenschaften
    Publiziert von De Gruyter
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    Inequality, Growth, and Congestion Externalities (2021)
    De Gruyter
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    Publikationsdatum: 2021-04-09
    Beschreibung: We describe and numerically simulate the aggregate and distributional properties of an endogenous growth model with an infrastructure externality which is subject to relative congestion. We show that the congested externality induces higher growth, greater inequality, labor/leisure trade-off ambiguities and an ineffective capital income tax for the government to achieve long-term redistribution goals. We demonstrate the economic implications of congestions in production and consumption externalities on the public to private capital ratio, growth and income distribution. Finally, we discuss alternative tax options for promoting inclusive growth.
    Print ISSN: 2194-6116
    Digitale ISSN: 1935-1690
    Thema: Wirtschaftswissenschaften
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  • 80
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    Fertilizing with composted cattle manure to meet agro-environmental targets in continuous corn and corn-soybean agroecosystems in southern Quebec (2021)
    Canadian Science Publishing
    Details
    Publikationsdatum: 2021-04-08
    Beschreibung: Balancing nutrient inputs from manure and supplemental inorganic fertilizers with crop requirements should achieve crop yield goals and agro-environmental targets. We asked if composted dairy cattle manure, alone or in combination with inorganic fertilizers, could sustain the corn and soybean yields, without increasing the residual soil N and soil P saturation of a sandy-loam soil in southern Quebec, Canada. Cropping systems were continuous silage corn and corn-soybean rotation, with each phase of the rotation grown every year, for 5-yr. Cropping systems were amended with compost at rates of 0, 15, 30 and 45 Mg (wet weight) ha-1, and received supplemental inorganic fertilizer to supply 200 kg N ha-1 yr-1 to corn while assuring that corn and soybean received 45 kg P ha-1 yr-1 and 125 kg K ha-1 yr-1 from compost and inorganic fertilizer. Crop yields were similar in composted-amended and inorganically-fertilized plots. Corn yield was limited by N availability, and there was no P or K limitation in corn and soybean. Soil P saturation in the 0–15 cm layer exceeded the agro-environmental limit of 13.1% P/Al for a sandy-loam soil in Quebec, indicating that the P input exceeded crop uptake. Residual soil N concentration was affected more by the crop than the fertilizer source, with greater residual soil N in plots with higher grain production. Crop-induced priming can explain how N fertilizer cycles through the soil microbial community and is gradually mineralized during the growing season, and why crop senescence may trigger residual soil N release after harvest.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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    MICROBIAL SOIL BIODIVERSITY IN BEECH FORESTS OF EUROPEAN MOUNTAINS (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-02-04
    Beschreibung: Fagus sylvatica is widely distributed across Europe thanks to its high adaptability in a wide variety of soils and climate. Microbial communities are essential for maintaining forest soil quality and are responsible for forest ecosystem functioning; the ability of soil microorganisms to respond to abiotic stressors (e.g. organic carbon losses, water scarcity, temperature changes), is crucial under ongoing environmental changes and also supports tree health. In this study, soil samples were collected from pure beech plots as part of the COST Action project CLIMO to find differences in microbial community characteristics and evaluate the effects of soil properties on microbial communities across altitude, latitude and longitude gradients. Positive relationships were found between organic carbon content and both microbial abundance and dehydrogenase activity. Dehydrogenase and catalase activities were altitude-correlated and microbial activities were longitude-correlated. In the most southern beech plot, microbial community was abundant and displayed high activities. This shows that microbial communities could help tree populations to better adapt to predicted changes in environmental conditions in the future. We suggest that research into forest health and beech performance should also test soil microbial enzymatic activity, in particular under changing climate conditions, to assist in identifying adaptation strategies.
    Print ISSN: 0045-5067
    Digitale ISSN: 1208-6037
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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    Did the FED React to Asset Price Bubbles? (2021)
    De Gruyter
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    Publikationsdatum: 2021-02-05
    Beschreibung: This paper investigates whether the Federal Reserve Bank (FED) reacted to asset price bubbles before the Great Recession and whether this affected macroeconomic variables. We estimate a DSGE model featuring a financial accelerator and a process for asset price bubbles with different Taylor-rule specifications. We find that a Taylor-rule with a feedback to Tobin’s Q and bubble shocks fits best. Our findings suggest that the FED followed a cleaning rather than a leaning approach prior to the global financial crisis (GFC). Then, we perform a counterfactual analysis and show that this policy created a lower interest rate prior to the GFC compared to a standard Taylor-rule without feedback to financial variables.
    Print ISSN: 2194-6116
    Digitale ISSN: 1935-1690
    Thema: Wirtschaftswissenschaften
    Publiziert von De Gruyter
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    Testing for exuberance in house prices using data sampled at different frequencies (2021)
    De Gruyter
    Details
    Publikationsdatum: 2021-08-09
    Beschreibung: We undertake Monte Carlo simulation experiments to examine the effect of changing the frequency of observations and the data span on the Phillips, P. C. B., S. Shi, and J. Yu. 2015. “Testing for Multiple Bubbles: Historical Episodes of Exuberance and Collapse in the S&P 500.” International Economic Review 56 (4): 1043–78 generalised supremum ADF (GSADF) test for explosive behaviour via Monte Carlo simulations. We find that when a series is characterised by multiple bubbles (periodically collapsing), decreasing the frequency of observations is associated with profound power losses for the test. We illustrate the effects of temporal aggregation by examining two real house price data bases, namely the S&P Case–Shiller real house prices and the international real house price indices available at the Federal Reserve Bank of Dallas.
    Print ISSN: 1081-1826
    Digitale ISSN: 1558-3708
    Thema: Mathematik , Wirtschaftswissenschaften
    Publiziert von De Gruyter
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    Cost implications of cluster plot design choices for precise estimation of forest attributes in landscapes and forests of varying heterogeneity (2021)
    Canadian Science Publishing
    Details
    Publikationsdatum: 2021-08-11
    Beschreibung: Tradeoffs occur when deciding between improving forest inventory precision by increasing sample size or by augmenting cluster plot design factors like size or subplot separation distance. The nature of these tradeoffs changes with variation in type and scale of the spatial pattern of the attribute of interest. In order to understand the impacts of relationships between type and scale of spatial heterogeneity and cluster plot design efficiency, we constructed a factorial simulation experiment and analysed relationships between forest inventory cost, cluster plot design factors, and different spatial heterogeneity scenarios constructed via simulation. To calculate cost, we constructed a cost model that accounted for both on- and between-plot costs. We found that type and scale of heterogeneity have important implications for plot design choices. Homogeneous stands and landscapes are the least-costly to inventory. Subplot area and count have stronger impacts than subplot separation on cost efficiency, particularly in landscapes with aggregated forest patterns and in stands with homogeneous tree patterns. We discuss results in the context of the physical interaction between cluster plot geometry and spatial patterns at different scales, provide computer code for simulations, and suggest principles that forest inventory cluster plot design specialists should consider when designing inventories.
    Print ISSN: 0045-5067
    Digitale ISSN: 1208-6037
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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  • 85
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    New genetically distinct phytoplasmas and insect carriers associated with pine tree disease revealed by a survey in Curonian Spit, Lithuania (2021)
    Canadian Science Publishing
    Details
    Publikationsdatum: 2021-08-11
    Beschreibung: Our previous studies reported that phytoplasma was the causative agent of the pine disease in Curonian spit, Lithuania. In this study, insects from diseased pine trees and their adjacent areas were collected from 2016 to 2019 to further identify potential insect vectors that spread phytoplasmas. A total of 1018 phloem-feeding insects (order Hemiptera) were identified, 98.62% of which were aphids (Aphididae), and no known phytoplasma vectors were found. Results from semi-nested PCR using phytoplasma-universal primers revealed that phytoplasmas were detected in scots pine aphids (Cinara pini), waxy grey pine needle aphids (Cinara pineti), and species-unknown aphids. Further sequence analysis and virtual RFLP analysis of aphid-harbored phytoplasma strains indicated that they were closely related to ‘Candidatus Phytoplasma pini’ (16SrXXI-A), but mainly 16SrXXI-A variants, which were also main strains identified in diseased pine trees. In addition, three new phytoplasma subgroups were delineated in the present study. Subgroups 16SrXXI-C and 16SrXXI-D were unveiled from previously identified (but classification was overlooked) Lithuanian pine phytoplasma strains. Subgroup 16SrXXI-E was discovered from the newly identified aphid-harbored phytoplasmas. Further transmission trial study on these aphids will provide insights into the epidemiology, and pathosystem of pine phytoplasma diseases, as well as the disease management.
    Print ISSN: 0045-5067
    Digitale ISSN: 1208-6037
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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  • 86
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    Evaluation of mapped-plot variance estimators across a range of partial nonresponse in a post-stratified national forest inventory (2021)
    Canadian Science Publishing
    Details
    Publikationsdatum: 2021-08-10
    Beschreibung: When conducting a forest inventory, sometimes portions of plots cannot be measured due to inaccessibility. Two primary methods have been presented to account for partial nonresponse in the estimation phase: 1) use a ratio-to-size estimator, or 2) apply an adjustment factor to all plot observations in proportion to the missing area. Both approaches provide identical estimates of the population mean, but the estimates of variance differ when partial nonresponse is present. Variance estimator performance was examined for a range of population forest area and partial nonresponse proportions in the sample. The ratio-to-size variance estimator performed unbiasedly with respect to simulation results, but the adjustment factor variance estimates were biased with the magnitude and direction dependent upon the forest area proportion and amount of partial nonresponse. The bias is relatively small when the partial nonresponse is small, which is often the case; however, the ratio-to-size method is preferred to ensure accurate variance estimation for a wide range of circumstances.
    Print ISSN: 0045-5067
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    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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    BIOCHAR IN TEMPERATE SOILS: OPPORTUNITIES AND CHALLENGES (2021)
    Canadian Science Publishing
    Details
    Publikationsdatum: 2021-08-12
    Beschreibung: Biochar, a carbon-rich material produced by the pyrolysis of organic residues, is frequently used as a soil amendment to enhance soil fertility and improve soil properties in tropical climates. However, in temperate agriculture, the impact of biochar on soil and plant productivity remains uncertain. The objective of this review is to give an overview of the challenges and opportunities of using biochar as an amendment in temperate soils. Among the various challenges, the type of feedstock and the conditions during pyrolysis produces biochars with different chemical and physical properties, resulting in contrasting effects on soils and crops. Furthermore, biochar aging, biochar application rates and its co-application with mineral fertilizer and/or organic amendments add further complexity to our understanding of the soil-amendment-plant continuum. Although its benefits on crop yield are not yet well demonstrated under field studies, other agronomic benefits of biochar in temperate agriculture have been documented. In this review, we proposed a broader view of biochar as a temperate soil amendment, moving beyond our current focus on crop productivity, and instead target its capacity to improve soil properties. We explored biochar’s benefits in remediating low productive agricultural lands, and its environmental benefits through long-term carbon sequestration and reduced nutrient leaching while curtailing our reliance on fertilizer input. We also discussed the persistence of beneficial impacts of biochar in temperate field conditions. We concluded biochar displays great prospective to improve soil health and its productivity, enhance plant stress resilience, mitigate greenhouse gas emissions and restore degraded soils in temperate agriculture.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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    Airborne laser scanning for quantifying criteria and indicators of sustainable forest management in Canada (2021)
    Canadian Science Publishing
    Details
    Publikationsdatum: 2021-07-01
    Beschreibung: Airborne laser scanning (ALS) has emerged as a technology capable of generating descriptors of vegetation structure and best available terrain information. Research and operational implementations of ALS data have highlighted their value for characterizing forest structure and generating spatially explicit and objective spatial coverages and mapping products for forest management. Continued emphasis to enhance forest stewardship is promoting novel methods to integrate ALS to detail non-timber ecosystem values like habitat, soil, and water. Standardized criteria and indicator frameworks such as the Canadian Council of Forest Ministers provide a reliable starting point for where ALS has opportunities to characterize ecosystems objectively regardless of location. In this review of primarily Canadian work, we highlight how ALS is becoming an increasingly viable technology for deriving meaningful indicators to meet sustainable forest management criteria. We review and highlight the value of ALS for quantifying indicators of biological diversity, ecosystem condition and productivity, soil and water, and the role of forests in global ecological cycles. We conclude by highlighting the need for increased education, tech transfer, flexible software, and reporting frameworks alongside five key considerations for using ALS to derive meaningful indicators of sustainable forest management.
    Print ISSN: 0045-5067
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    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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  • 89
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    Introduction: Ecology and silviculture of temperate mixedwood forests (2021)
    Canadian Science Publishing
    Details
    Publikationsdatum: 2021-07-01
    Print ISSN: 0045-5067
    Digitale ISSN: 1208-6037
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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  • 90
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    Partial special issue: Temperate mixedwood forests: ecology and management of hardwood–softwood mixtures (2021)
    Canadian Science Publishing
    Details
    Publikationsdatum: 2021-07-01
    Print ISSN: 0045-5067
    Digitale ISSN: 1208-6037
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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  • 91
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    Dynamic treatment units in forest planning using cell proximity (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-07-01
    Beschreibung: In forest management planning, the dynamic treatment unit (DTU) approach has become an increasingly relevant alternative to the traditional planning approach using fixed stands, due to improved remote sensing techniques and optimization procedures, with the potential for the higher goal fulfillment of forest activities. For the DTU approach, the traditional concept of fixed stands is disregarded, and forest data are kept in units with a high spatial resolution. Forest operations are planned by clustering cells to form treatment units for harvest operations. This paper presents a new model with an exact optimization technique for forming DTUs in forest planning. In comparison with most previous models, this model aims for increased flexibility by modelling the spatial dimension according to cell proximity rather than immediate adjacency. The model is evaluated using a case study with harvest flow constraints for a forest estate in southern Sweden, represented by 3587 cells. The parameter settings differed between cases, resulting in varying degrees of clustered DTUs, which caused relative net present value losses of up to 4.3%. The case without clustering had the lowest net present value when considering entry costs. The solution times varied between 2.2 s and 42 min 6 s and grew rapidly with increasing problem size.
    Print ISSN: 0045-5067
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    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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  • 92
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    A species-specific, site-sensitive maximum stand density index model for Pacific Northwest conifer forests (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-08-01
    Beschreibung: Maximum stand density index (SDIMAX) models were developed for important Pacific Northwest conifers of western Oregon and Washington, USA, based on site and species influences and interactions. Inventory and monitoring data from numerous federal, state, and private forest management groups were obtained throughout the region to ensure a wide coverage of site characteristics. These observations include information on tree size, number, and species composition. The effects and influence on the self-thinning frontier of plot-specific factors such as climate, topography, soils, and geology, as well as species composition, were evaluated based on geographic location using a multistep approach to analysis involving linear quantile mixed models, random forest, and stochastic frontier functions. The self-thinning slope of forest stands dominated by Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) was found to be –1.517 and that of stands dominated by western hemlock (Tsuga heterophylla (Raf.) Sarg.) was found to be –1.461, leading to regionwide modelled SDIMAX values at the 95th percentile of 1728 and 1952 trees per hectare, respectively. The regional model of site-specific SDIMAX will support forest managers in decision-making regarding density management and species selection to more efficiently utilize site resources toward healthy, productive forests.
    Print ISSN: 0045-5067
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    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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    Lodgepole pine and interior spruce radial growth response to climate and topography in the Canadian Rocky Mountains, Alberta (2021)
    Canadian Science Publishing
    Details
    Publikationsdatum: 2021-07-01
    Beschreibung: Climate change may have spatially variable impacts on growth of trees in topographically diverse environments, making generalizing across broad spatial and temporal extents inappropriate. Therefore, topography must be considered when analyzing growth response to climate. We address these topo-climatic relationships in the Canadian Rocky Mountains, focusing on lodgepole pine (Pinus contorta Douglas ex Louden) and interior spruce (Picea glauca (Moench) Voss × Picea engelmannii hybrid Parry) growth response to climate, Palmer drought severity index (PDSI), aspect, and slope angle. Climate variables correlate with older lodgepole pine growth on south- and west-facing slopes, including previous August temperature, winter and spring precipitation, and previous late-summer and current spring PDSI, but younger lodgepole pine were generally less sensitive to climate. Climate variables correlate with interior spruce growth on all slope aspects, with winter temperature and PDSI important for young and old individuals. Numerous monthly growth–climate correlations are not temporally stable, with shifts over the past century, and response differs by slope aspect and angle. Both species are likely to be negatively affected by moisture stress in the future in some, but not all, topographic environments. Results suggest species-specific and site-specific spatiotemporally diverse climate–growth responses, indicating that climate change is likely to have spatially variable impacts on radial growth response in mountainous environments.
    Print ISSN: 0045-5067
    Digitale ISSN: 1208-6037
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
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    Comparison of time-based versus state–space stand growth models for tropical hybrid Eucalyptus clonal plantations in Sumatera, Indonesia (2021)
    Canadian Science Publishing
    Details
    Publikationsdatum: 2021-08-01
    Beschreibung: The pulp and paper industry in Indonesia is the tenth largest producer in the world, with Acacia and Eucalyptus as the main genera used for production; however, limited publications exist related to Eucalyptus growth models in Indonesia compared with other regions. Time-based models have been developed in which height, stand density, and basal area are predicted based on initial conditions and age. In contrast, a state–space approach utilizes the rate of change of these three state variables. Previous direct comparisons of these two approaches are generally limited. Consequently, the objective of this study was to compare two stand-level growth modeling approaches for Eucalyptus hybrid species on Sumatera (Sumatra) Island using both time-based and state–space methods. Our results indicate that dynamic models using either time-based or state–space approaches are adequate for predicting stand parameters to rotation age. A modified Bazukis matrix indicated that the behavior of both methods produced reliable predictions that were biologically reasonable in terms of stand development; however, the time-based approach provided better performance than the state–space approach on a variety of equivalence tests and goodness-of-fit statistics. Overall, the analysis highlights the advantages and disadvantages of these two commonly used, yet highly contrasting, stand-level growth modeling approaches, which need further consideration and evaluation.
    Print ISSN: 0045-5067
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    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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    An adapted Weibull function for agricultural applications (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-06-25
    Beschreibung: The Weibull function is applied extensively in the life sciences and engineering but underused in agriculture. The function was consequently adapted to include parameters and metrics that increase its utility for characterizing agricultural processes. The parameters included initial and final dependent variables (Y0 and YF, respectively), initial independent variable (x0), a scale constant (k), and a shape constant (c). The primary metrics included mode, integral average, domain, skewness, and kurtosis. Nested within the Weibull function are the Mitscherlich and Rayleigh functions where c is fixed at 1 and 2, respectively. At least one of the three models provided an excellent fit to six example agricultural datasets, as evidenced by large adjusted coefficient of determination (RA2 ≥ 0.9266), small normalized mean bias error (MBEN ≤ 1.49%), and small normalized standard error of regression (SERN ≤ 8.08%). The Mitscherlich function provided the most probable (PX) representation of corn (Zea mays L.) yield (PM = 87.2%); Rayleigh was most probable for soil organic carbon depth profile (PR = 96.4%); and Weibull was most probable for corn seedling emergence (PW = 100%), nitrous oxide emissions (PW = 100%), nitrogen mineralization (PW = 58.4%), and soil water desorption (PW = 100%). The Weibull fit to the desorption data was also equivalent to those of the well-established van Genuchten and Groenevelt–Grant desorption models. It was concluded that the adapted Weibull function has good potential for widespread and informative application to agricultural data and processes.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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    Mixedwood management positively affects forest health during insect infestations in eastern North America1 (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-07-01
    Beschreibung: Mixedwood stands are composed of hardwoods and softwoods, with neither comprising greater than 75%–80% of basal area or aboveground biomass. By conferring associational resistance and greater resilience to forests when stressed or disturbed, the more diverse composition of mixedwood stands contributes to forest health. We analyzed three examples where mixedwood stands are more resistant to insect infestations in eastern North America. In balsam fir (Abies balsamea L. Mill.) and spruce (Picea spp.) forests, susceptibility and vulnerability to spruce budworm infestations is reduced with increasing hardwood density. In mid-Atlantic oak-dominated forests, oak mortality following gypsy moth infestations was much greater in oak-dominated forests than in oak–pine mixedwoods, while pine mortality during southern pine beetle infestations was greater in pine-dominated forests than in oak–pine mixedwoods. Overall, mixedwood stands have greater resistance to infestations of defoliators and bark beetles and recover more rapidly from disturbances, reducing economic losses associated with tree mortality and mitigating short-term impacts to ecosystem functioning resulting from insect damage, especially carbon sequestration. Finally, we discuss challenges and opportunities for mixedwood management to minimize insect damage. Management strategies that incorporate mixedwood stands may provide better continuity in supply of forest products and ecosystem services in the face of projected increases in insect infestations associated with changing climate.
    Print ISSN: 0045-5067
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    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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    Sector subsampling for basal area ratio estimation: an alternative to big BAF sampling (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-08-01
    Beschreibung: Big basal area factor (big BAF) sampling is a widely used subsampling method to select measure-trees. Several studies have shown big BAF sampling to be an efficient sampling scheme. In this study, we use sector sampling (Smith et al. 2008, For. Sci. 54: 67–76) as an alternative subsample selection method. Based on some simulated mapped stands derived from three balsam fir (Abies balsamea (L.) Mill.) spacing trials in western Newfoundland, we show that sector subsampling is comparable to big BAF sampling in terms of estimated mean basal area ratios and their associated standard errors. Differences between big BAF sampling and sector sampling methods showed less than 1% difference across the three sites. As with big BAF sampling, changes in sample intensity had no significant (p 〈 0.05) effects on the accuracy of estimating mean biomass to basal area ratios and the resulting estimated mean biomasses per unit area.
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    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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    Pedological trends and implications for forest productivity in a Holocene soil chronosequence, Calvert Island, British Columbia, Canada (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-06-18
    Beschreibung: Chronosequence studies of soil formation and ecosystem development provide important insights into the pathways and rates of change occurring on centennial and millennial time scales. In cool or temperate humid environments, Podzols are the predominant soil type formed under coniferous forests in coarse-textured parent material and have been a major focus of chronosequence studies. This study examined the rate and mechanisms of Podzol development and related forest productivity in a sand dune chronosequence in a hypermaritime climate in coastal British Columbia (BC). The sequence spans 10 760 ± 864 yr over eight sites and is the first documented chronosequence in coastal BC to span most of the Holocene Epoch. Soil samples from each genetic horizon were analyzed for bulk density, pH and concentrations of total carbon (C), pyrophosphate- and oxalate-extractable aluminum (Al) and iron (Fe), and total elements. Within ∼3500 yr, a mature Podzol had formed, with cemented horizons (ortstein and placic) present. Organo-metallic complexation appeared to be the dominant mechanism involved in podzolization. Despite a mild, moist climate conducive to chemical weathering, all soils had similarly low values for the chemical index of alteration, suggesting that congruent dissolution of primary minerals may be occurring. Ecosystem retrogression is apparent in the latter stages of the chronosequence — a phenomenon not previously documented in coastal BC. Further research is needed to examine the interactions of nutrient limitation, soil physical barriers, and other possible drivers of ecosystem retrogression.
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    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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    Relative importance of climate, vegetation, and spatial factors in the community and functional composition of wood-inhabiting fungi in discontinuously distributed subalpine spruce forests (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-07-01
    Beschreibung: Wood-inhabiting fungi are critically important for the decomposition of coarse woody debris (CWD). To evaluate the relative importance of climate, vegetation, and spatial factors in the functional composition of fungal communities that inhabit CWD in discontinuously distributed subalpine Hondo spruce (Picea jezoensis (Sieb. & Zucc.) Carr. var. hondoensis (Mayr) Rehder) forests, a metabarcoding analysis was conducted on spruce deadwood samples obtained from six subalpine forests in central Japan using a high-throughput DNA sequencing technique. We detected 454 fungal operational taxonomic units (OTUs) from 67 spruce CWDs and determined that spatial factors explained a larger fraction of community variation than environmental (climate and vegetation) factors at all six study sites. However, environmental factors explained a larger fraction than spatial factors if we excluded data from one site that is geographically distant from other study sites. The OTU number and the occurrence of brown-rot fungi were positively associated with mean annual temperature and negatively associated with mean annual precipitation. Similarly, the principal component of forest vegetation significantly affected the OTU number and occurrence of brown-rot fungi. Precipitation seasonality was positively associated with the OTU number of undefined saprotrophs. These results suggest that fungal OTUs belonging to different functional groups respond differently to environmental variables.
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    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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    Mixtures of airborne lidar-based approaches improve predictions of forest structure (2021)
    Canadian Science Publishing
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    Publikationsdatum: 2021-08-01
    Beschreibung: The most common method for modeling forest attributes with airborne lidar, the area-based approach, involves summarizing the point cloud of individual plots and relating this to attributes of interest. Tree- and voxel-based approaches have been considered as alternatives to the area-based approach but are rarely considered in an area-based context. We estimated three forest attributes (basal area, overstory biomass, and volume) across 1680 field plots in Arizona and New Mexico. Variables from the three lidar approaches (area, tree, and voxel) were created for each plot. Random forests were estimated using subsets of variables based on each individual lidar approach and mixtures of each approach. Boruta feature selection was performed on variable subsets, including the mixture of all lidar-approach predictors (KS-Boruta). A corrected paired t test was utilized to compare six validated models (area-Boruta, tree-Boruta, voxel-Boruta, KS-Boruta, KS-all, and ridge-all) for each forest attribute. Based on significant reductions in error (SMdAPE), basal area and biomass were best modeled with KS-Boruta, while volume was best modeled with KS-all. Analysis of variable importance shows that voxel-based predictors are critical for the prediction of the three forest attributes. This study highlights the importance of multiresolution voxel-based variables for modeling forest attributes in an area-based context.
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    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
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