查看更多>>摘要：? 2022 Elsevier B.V.Arthropod diversity in agricultural landscapes is important to maintain numerous ecosystem services. Most arthropods, however, need shelter habitats for overwintering embedded in agricultural landscapes. Habitats created by perennial agri-environmental schemes (AES) such as flowering fields can provide such overwintering places in addition to nesting sites and food resources. However, it is unclear, to which extent arthropods use such flowering fields for overwintering. We assessed the emergence of six functionally relevant arthropod groups (wild bees, hoverflies, wasps, carabid beetles, staphylinid beetles and spiders) with emergence cages on wheat fields and on four types of flowering fields differing in temporal continuity (age and time since last soil disturbance). Wild bee richness and abundance was highest in flowering fields that had undergone soil disturbance in the previous year while recent soil disturbance was clearly detrimental. Natural enemies were mostly unaffected by temporal continuity and hoverflies emerged most abundantly from wheat fields. Carabid beetle richness and densities of carabid and staphylinid beetles were positively affected by recent soil disturbance while hoverfly densities were negatively affected. Further assemblage composition of emerging wild bees and carabid beetles differed between habitat types. Our results indicate that most natural enemies overwinter even in flowering fields with low temporal continuity and recent soil disturbance while wild bees need habitats of higher temporal continuity for overwintering. We thus propose a mix of flowering habitats with different degrees of temporal continuity embedded in the agricultural landscape to make AES more effective towards the provisioning of overwintering sites for ecosystem service providers. We conclude that a better understanding of the overwintering ecology of different arthropod groups is required to counteract current biodiversity decline in agricultural landscapes.
查看更多>>摘要：? 2022 The AuthorsHow much can we increase biomass yield by promoting land conversion from annual to perennial crops? Will increased biomass extraction for biorefineries reduce soil organic carbon (SOC) and total nitrogen (TN) stock? Which cropping system is more stable for biomass production over time? To our knowledge, no study has concurrently investigated the effects of land conversion from annual to perennial crops on biomass yield, yield stability, and changes in SOC and TN stock, which limits the understanding and application of sustainable agroecosystems producing biomass for biorefineries. Based on five-year continuous observations in central Jutland Denmark, our results showed that perennial crops significantly increased biomass yield by 19% and yield stability by 88% compared to annual crops. Perennial crops significantly increased SOC content by 4% and SOC stock by 11% at 0–100 cm depth across the five years. The opposite responses of SOC content and stock under annual and perennial crops led to even more significant differences between the crop types. Perennial crops had no effect on soil TN content and increased soil TN stock to one meter depth by 22%, whereas continuous annual crops had no effect on it. Neither annual nor perennial crops had effects on SOC and TN stock when estimated based on equivalent soil mass because the soil density increased under perennial crops. Our results showed that changes in SOC and TN stock between annual and perennial crops varied with the specific calculating methods (fixed depth/equivalent mass), thus the selected methods should be clearly defined in the future research. Increases in SOC content at one meter depth were positively correlated with biomass yield and yield stability, suggesting a win-win strategy for climate mitigation and food security. Altogether, our results highlight the potential to redesign the current cropping system for sustainable intensification by selecting proper perennial crops for green biorefineries.
van der Pol L.K.Robertson A.Schipanski M.Wallenstein M.D....
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查看更多>>摘要：? 2022 The AuthorsSemi-arid regions support the majority of global wheat production, but they are threatened by continued soil erosion and increased risk of drought and extreme temperatures from climate change. Enhancing soil organic matter (SOM) is a key adaptation strategy for sustaining agriculture in these regions because it can improve water retention and nutrient cycling. When seeking to increase SOM, growers face a dilemma, known as the ‘soil carbon (C) dilemma’ (Janzen, 2006): How can SOM be increased, while also increasing the release of nutrients that accompanies decomposition? Our observational study examined whether growers could address this dilemma through intensification with diverse grain crops. We specifically tested whether incorporating legumes into a continuous rotation influences the form and amount of SOM as well as productivity in farms of the central Great Plains region of the U.S. by contrasting three, no-till rotation systems: 1) conventional wheat-fallow; 2) continuous grain-only rotations, and 3) continuous grain rotations that incorporate a legume crop. We sampled on-farm fields and experimental agricultural research station plots that had received one of these rotations for at least eight years. We compared yield, soil organic C (SOC), and nitrogen (N) stocks in bulk soil to 1 m, as well as SOC and N in particulate organic matter (POM) and mineral-associated organic matter (MAOM) in surface soils (0–10 cm) among the different rotations. We also estimated the long-term effects of the rotations on SOC fractions through a simulation of each rotation with the MEMS 1.0 model, verified with measured data. We found that intensifying the rotation with continuous grains led to 1.5-fold increase in aggregate size but did not change SOC stocks. Incorporating a legume to the continuous grain rotation resulted in 1 Mg C ha-1 more SOC on average in surface soil compared to wheat-fallow rotations. No significant soil changes among rotations were observed at depth. Longer-term simulations of these cropping systems suggest that including legumes could allow for 10% greater SOC gains over time compared to wheat-fallow. Since legume incorporation also increased crop yields across the full rotation cycle, our results support our hypothesis that growers can solve the ‘soil C dilemma’ by simultaneously increasing the quantity and N-content of soil input through continuous cropping with both grains and legumes.
查看更多>>摘要：? 2022 Elsevier B.V.Land-use changes have affected biodiversity and the role it plays in ecological functioning throughout the Neotropics. It is important to understand the response of species to land-use changes to recommend appropriate management and conservation strategies. This is particularly true when land use systems include agroforestry systems, such as shade coffee plantations. In this study, we evaluated the taxonomic diversity of birds and the effect of land-use types (cattle pastures, shade coffee plantations, and forests in late successional stages) on the presence of functional groups at the local and landscape level in a Mexican cloud forest landscape. We carried out monthly bird surveys for one year in 90 circular points with a radius of 25 m (30 points per land use type) in which we compared bird taxonomic diversity using effective diversity or Hill numbers. We analyzed the composition and abundance of bird species and functional groups across land use types using nonmetric multidimensional scaling and tested the effect of predictor variables on functional group abundance at the local and landscape level using ordination methods and generalized linear models. In total, we recorded 134 bird species belonging to 27 families. Bird species richness was highest in late forests. Bird species diversity was high in both late forests and coffee plantations in comparison to cattle pastures. There was a greater similarity in the bird species composition and functional groups in both late forests and coffee plantations compared to cattle pastures. Bird functional groups favored by more complex vegetation structure included forest granivores, small insectivorous flycatchers, and nectarivores, groups that were also present in more diverse plant communities at the local level and by humid forests associated with shade coffee plantations at the landscape level. Avian granivores associated with disturbed environments were negatively related with vegetation complexity and forest cover across scales and omnivores were positively associated with disturbed areas at the landscape level. This study shows the susceptibility of certain bird functional groups to different land use types at distinct spatial scales and highlights the role of shade coffee plantations as a land use type that maintains taxonomic and functional diversity of birds in Neotropical cloud forests.
查看更多>>摘要：? 2022 Elsevier B.V.Winegrowers have diversified their weed management practices over the last two decades changing the structure and the composition of weed communities. Complementary to taxonomic studies, trait-based approaches are promising ways for a better understanding of weed community responses to environmental and agronomic filters. In the present study, the impacts of climate, soil characteristics, seasons and weed management practices (chemical weeding, tillage and mowing) were assessed on weed communities from 46 plots in three French wine-growing regions (Champagne, Languedoc and Rh?ne valley). These agro-environmental gradients structuring weed communities according to their combinations of traits were highlighted using multivariate analysis (RLQ). The impacts of these filters on Community Weighted Means (CWM) and Community Weighted Variance (CWV) of weed communities were analysed using mixed and null modelling. Our results showed that spatio-temporal and weed management practice variables explained from 13% to 48% of the total variance of CWM (specific leaf area, maximum height, seed mass, flowering onset and duration and lateral spread). Region, seasonality and management practices explained 53%, 28% and 19% of CWM marginal variance, respectively. Weed management impacted CWM and CWV through two main gradients: (i) a soil disturbance gradient with high mechanical disturbance of soil in tilled plots and low mechanical disturbance in chemically weeded plots and (ii) a vegetation cover gradient with high vegetation abundance in mowed plots compared to barer soils in tilled and chemically weeded plots. In Languedoc, chemical weeding filtered weed communities with ruderal strategy trait values (low seed mass, small-stature) while mowed communities were more competitive (higher seed mass, higher stature and lower SLA). In Languedoc and Champagne, tillage favoured communities with high seed mass that increases the viability of buried seeds and high lateral spread values associated to the ability to resprout after tillage. This study demonstrated that trait-based approaches can be successfully applied to perennial cropping systems such as vineyards, in order to understand community assembly to better guide weed management practices.
查看更多>>摘要：? 2022 Elsevier B.V.In recent years, rice-crayfish co-culture has been widely promoted as a newly emerging farming mode in China. The peripheral trench for crayfish farming and paddy field drainage in this farming mode can alter nitrogen (N) fertilizer deposition and ammonia (NH3) diffusion. However, the effect of the peripheral trench on NH3 volatilization remains unclear. We hypothesized that the peripheral trench under rice-crayfish co-culture (RC) can reduce total NH3 volatilization and enhance rice N uptake. Here, a field experiment was conducted to investigate the effect of different rice farming patterns [RC and rice monoculture (RM)] on NH3 volatilization and rice N uptake during the 2018–2019 rice growing seasons. NH3 volatilization from both the paddy field and the peripheral trench under RC was determined. Compared with RM, RC reduced the mean urease activity by 28.2–29.4% in the paddy field by promoting N fertilizer deposition into the peripheral trench. The decrease in urease activity finally reduced the total NH3 volatilization by 16.1–19.6% from both the paddy field and the peripheral trench. As a special drainage structure, the peripheral trench increased the rice N uptake by 16.7–18.3% under RC compared with that under RM by reducing NH3 volatilization.
查看更多>>摘要：? 2022 The AuthorsPermanent grasslands cover 34% of the European Union's agricultural area and are vital for a wide variety of ecosystem services essential for our society. Over recent decades, the permanent grassland area has declined and land use change continues to threaten its extent. Simultaneously, the management intensity of permanent grasslands increased. We performed a systematic literature review on the multifunctionality of permanent grasslands in Europe, examining the effects of land use and management on 19 grassland ecosystem service indicators. Based on the evidence in 696 out of 70,456 screened papers, published since 1980, we found that both land use change and intensification of management decreased multifunctionality. In particular, preventing conversion of permanent grasslands to croplands secured the delivery of multiple ecosystem services. A lower management intensity was associated with benefits for biodiversity, climate regulation and water purification, but impacted the provision of high-quality animal feed. Increasing the number of species in the sward enhanced multifunctionality of permanent grassland without significant trade-offs such as losses in production. Our review covered many aspects of land use, management and ecosystem services, but we also identified areas with no or only few studies. The most prominent gaps were related to comparisons between permanent and temporary grasslands, and effects of management practices on the provision of cultural values, and on erosion and flood control. We suggest that, despite apparent changes in human dietary preferences, the protection of permanent grasslands in Europe must be prioritised. At the same time, considering the need to reduce ruminant livestock's contribution to climate change, the time seems ripe to increase support for low-intensity grassland management to optimise the provision of essential ecosystem services from Europe's permanent grasslands.
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