Raderschall, ChloeLundin, OlaLindstrom, Sandra A. M.Bommarco, Riccardo...
14页
查看更多>>摘要：Intensively managed agricultural landscapes have degraded the provisioning of diverse and continuous forage and shelter habitats for arthropods and weakened the delivery of ecosystem services such as insect crop pollination and biological pest control. In response, farmers are incentivised to sow flower strips along field margins to counteract resource bottlenecks. Yet, it is poorly understood how effective this diversification practice is when combined with the supplementation of honeybee (Apis mellifera L.) hives, which is commonly used to boost insect pollination in flowering crops. Honeybees share floral resources with wild pollinators and natural enemies of pests, which could lead to competition for food resources. We sampled pollinators, natural enemies and their pests as well as estimated the benefit of insect pollination in 17 organic faba bean (Vicia faba minor L.) fields in southern Sweden either with or without sown annual flower strips and with or without added honeybee hives. In fields with flower strips, bumblebee (Bombus spp.) densities were redistributed from field edges to interiors but without affecting their overall densities. Flower strips enhanced silver Y moth (Autographa gamma L.) densities and carabid beetle Shannon diversity along the field edge, and overall spider activity density. The supplementation of honeybee hives enhanced honeybee densities, overall ladybird beetle densities, black bean aphid (Aphis fabae Scop.) densities along field edges, but deterred silver Y moths and pushed bumblebees towards the field interior. Bean mass per plant was higher in insect pollinated plants compared with bagged, self-pollinated plants. This insect pollination benefit was independent of honeybee hive supplementation and the flower strip treatment suggesting that faba bean fields were not deficient in pollinator visits. We conclude that flower strips did not provide sufficient floral resources to increase overall wild pollinator densities in faba bean fields. Yet, annual flower strips attracted and facilitated ground-dwelling predators, especially spiders, to faba bean fields, likely by providing beneficial shelter habitats. It is worth noting that 2018, in which we collected our data, was characterised by late frosts in spring followed by an unusually hot and dry summer. While these unforeseen weather conditions together with a relatively small sample size might limit the generalisation of our results, we argue that conducting experiments under such conditions provide insights into the effectiveness of agri-environmental schemes under climate change, especially considering that such weather conditions are becoming increasingly more frequent.
Monge, OttoDullinger, StefanFusani, LeonidaSchulze, Christian H....
10页
查看更多>>摘要：The expansion of the agricultural frontier in the species-rich tropical regions of the world has generated conflicts between the need to secure food production and the conservation of biodiversity. As natural areas give way to farmlands, the future of sensitive taxa may depend on how intensively the crops are cultivated. In order to better understand the response of avian diversity to cultivation intensity in tropical farmlands, analyses of species richness are increasingly being complemented with information about the birds' functional roles and evolutionary history. In this study, we analysed the association of several features of vegetation composition and structure, as indicators of cultivation intensity in coffee farms in Costa Rica, on the taxonomic, functional and phylogenetic dimensions of avian biodiversity at the local scale across an approximately 2000 m elevational gradient. Bird detections and vegetation measurements were conducted at 120 randomly selected circular plots of 25 m radius, across 51 coffee farms. Using regression modelling and multi-model inference, we related six vegetation features to five biodiversity metrics in this system and evaluated whether the results differed among elevational zones. The most influential vegetation feature was the number of trees with a diameter-at-breast height larger than 30 cm, promoting higher richness, functional redundancy and phylogenetic structure of avian species. Shade from canopy cover and the number of non-coffee crops increased species and phylogenetic richness, respectively. The effect of individual vegetation features on particular biodiversity metrics varied across elevation, possibly due to the idiosyncratic response of each dimension to the elevation gradient or because of local ecological processes. We conclude that vegetation features related to cultivation intensity have effects on avian diversity, but that these effects differ among biodiversity metrics and are sensitive to the environmental context. Consequently, targeted conservation management should be based on more comprehensive studies that include more than one biodiversity dimensions as well as variation in relevant environmental context. In general, our results suggest that, when designing conservation strategies for birds in coffee-dominated landscapes, there is likely no "one-size-fits-all" strategy.
查看更多>>摘要：Insects are a functionally diverse group, with economically relevant roles on key ecosystem services, such as pollination. The current trend of biodiversity loss and consequent degradation of ecosystem services delivered by insects is leading to additional pressure on modern agriculture, particularly in crops that depend on insects for pollination. Understanding how insect pollinator diversity varies at local and landscape scales is very important to recognize trends in pollinator populations. The present work quantified the effect of in-field management practices and different landscape types on insect pollinator communities in kiwifruit, a pollinator-dependent crop. Twenty-two orchards were selected and characterized for in-field practices, landscape structure, plant pollinator interactions, and productivity. We observed that orchards with practices that are less harmful to insect pollinators are related to a higher pollinator diversity and higher abundances of certain wild pollinator groups, although this was not related with increased productivity. Additionally, in the studied production region, agricultural dominated landscapes harbor lower pollinator diversity, lower wild pollinators abundance and higher managed honeybee abundance than forest and herbaceous dominated landscapes, but no differences were detected in productivity among landscape types. In turn, abundance of Bombus spp. and the use of pollination support practices were significantly and positively correlated with orchard productivity. Despite the differences in pollinator communities, comparable yields were observed across different landscape types. Additionally, simple changes towards less harmful agricultural practices and the presence of forest and herbaceous habitats can promote wild pollinators and respective pollination services.
查看更多>>摘要：The soil microbial community is an essential biotic component in plant-soil feedback processes that can alter plant fitness, growth, and reproduction. Further, they may exert an influence on plants by forming a microbial association network. Accordingly, pronounced changes in the soil microbial community induced by climate warming is vital when evaluating the future risks on plants posed by global climate change. Although the climate warming issue has gained much attention for its impact upon soil microbial communities, attempts to identify its effects on their network associations through plant growth stages, especially in agroecosystems, remains limited and generally understudied. Here, the effects of elevated temperature in association with wheat plant growth upon soil bacteria, fungi, and arbuscular mycorrhizal (AM) fungi were determined in a field experiment. Our results revealed the alpha diversity of soil bacteria (ACE and Chao values) decreased through plant growth stages, while the relative abundances of bacteria and fungi between seeding time and mature stage were revealed significantly distinct in the PCA analysis. The derived microbial association network showed that warming could enhance the complexity of the network and wheat planting might weaken it. We also found the wheat planting and warming could increase the number of keystone species. Furthermore, the keystone species had the strongest relationship with the grain mass and quality of wheat. These findings could provide a better understanding of plant-soil feedback dynamics in wheat crops, along with those in other similar agroecosystems in the future under global climate change.
查看更多>>摘要：Massive grasslands on the Qinghai-Tibetan Plateau(QTP) provide vital ecosystems services, which have been decreased by land degradation associated with global change. Effective efforts and actions of restoration and management are required to promote the sustainable development of these grassland ecosystems with global importance. This special issue collected numerous papers to address share the innovative theoretical foundations and practical approaches for restoring and protecting QTP's grassland ecosystems in the era of global change. The findings from the collected papers of this special issue stated that the ecosystems services of the QTP's grasslands are declining due to weakened interfaces among soil, plant and grazing animals in the QTP's grassland ecosystems by climate and land use changes. Applicable actions such as climate change mitigation and adaptation, close-to-nature restoration, rotational grazing regime with moderate grazing intensity should be taken to enhance the ecosystem services through rebuilding rational soil-plant-animal interfaces.
查看更多>>摘要：Small farm size and fragmented land are considered constraining agricultural development. This study uses the Vietnam Household Living Standard Survey 2016 (VHLSS 2016) dataset to measure the technical efficiency of rice smallholders and its determinants, including farm size, in the Mekong Delta. Data envelopment analysis was employed to examine efficiency scores in the first stage based on data of 506 paddy farms. The overall efficiency calculated through slack-based measure was low at 0.59 and the input slacks were quite large. This indicated that local farmers have not been using their resources efficiently in producing paddy. Further, farms smaller than 2 ha faced low overall efficiency at 54% and higher slacks in terms of all input types. The second-stage Tobit result showed that all types of efficiency could be improved if farmers expanded their farm size and reduced the over-use of inputs. Thus, enabling small farms to achieve economies of scale through collective farming in the Large Field Model (LFM) will be critical for upgrading production efficiency and reducing slacks as labor costs rise and natural resources are constrained. It is recommended that farmers should follow strictly eco-friendly farming packages in order to reduce their current excessive usage of seed cost by 28 USD/ha, pesticides by 61 USD/ha, and fertilizers by 155 kg/ha to reach efficient production frontier. The government needs to take measures to replicate and closely monitor climate smart agriculture programs in large-scale production to improve the overall efficiency of paddy sector, in addition to the important goal of protecting the environment and natural resources of the region.Availability of data and materials: The VHLSS 2016 questionnaire section and dataset analyzed in this study are available from the corresponding author on reasonable request.
查看更多>>摘要：Returning plant residue to farmland maintains or enhances the fertility and productivity of soils to offset degradation of soil quality in cultivated agricultural ecosystems. Although stover mulching serves as a manageable, efficient practice that has been widely used to restore soil health and to sustain ecosystems, it is unclear how changing the frequency and quantity of stover mulching in the long run affects the soil ecosystem, and it remains elusive what the underlying mechanisms are that associated with the features and responses of belowground microbiomes in the process. Here, we investigated a China Mollisol subjected to a 10-year, no-till management scheme with two-level frequencies (i.e., high frequency with continuous mulching per year and low frequency with interval mulching every 3 years) and two-level quantities (i.e., low quantity, 33%, and high quantity, 67%) of maize stover mulching. We found that the frequency, but not the quantity, significantly influenced life-history strategies of bacterial communities and crop yields. Specifically, frequency of stover mulching significantly affected structure of bacterial communities in deeper soil layers at 5-10 cm and 10-20 cm; at 5-10 cm, high frequency of stover mulching showed significantly higher bacterial diversity and richness than low frequency mulching. The complex and close-knit co-occurrence network of bacterial communities in soils under high frequency stover mulching was associated predominately with copiotrophs (e.g., Bacteroidetes and Alphaproteobacteria) and potential metabolic functions that involved carbohydrates, amino acids, and lipids; under low frequency stover mulching, the simple and loose co-occurrence networks were associated with oligotrophs (e.g., Arthrobacter) and potential functions that involved cell processes. We also found that high frequency stover mulching maintained the storage of soil organic carbon, improved the stocks of soil total phosphorus at 16.0% and potassium at 4.7%, and enhanced crop productivity at 14.1% than low frequency, independent of the quantity of stover mulching. Together, we suggest maintaining a low-quantity while high frequency of mulch might efficiently boost soil health without compromising crop yields and as well optimize the use of stover. Our study revealed that applying a small quantity of stover mulching at high frequency might be sufficient for regenerative agriculture by efficiently improving soil health.
Preza-Fontes, GiovaniChristianson, Laura E.Greer, KristinBhattarai, Rabin...
9页
查看更多>>摘要：Cover crops and in-season nitrogen (N) management are promoted as key conservation practices for reducing nitrate leaching losses from agricultural fields. However, their combined effects on soil nitrous oxide (N2O) emissions per unit of crop productivity remains uncertain. These practices might contribute to high N2O emissions by providing N and C substrates for microbial denitrification activity, especially when in-season N application coincides with cover crop decomposition. The objective of this study was to evaluate the effects of N application timing and cereal rye (CR, Secale cereale L) cover crops on area-and yield-scaled soil N2O emissions in continuous maize (Zea mays L.) over 3-yr (2018-2020). Treatments were: Pre-Season-N: 224 kg N ha-1 split applied in fall + pre-plant in 2018, or as single pre-plant applications in 2019 and 2020; In-Season-N: pre-plant + side-dress (growth stage V6-V7); In-Season-N + CR: ; and a zero N plot as the Control. We found that shifting from pre-season to in-season split N application did not significantly affect area-or yield-scaled N2O emissions in any year. Despite high N2O spikes for the In-Season-N + CR following side-dress N application in all years, this did not translate to consistently higher cumulative N2O emissions. Compared with Pre-Season-N and In-Season N, In-Season-N + CR significantly increased area-and yield-scaled N2O emissions by approximately 50% in 1 of 3 years. These results suggest the combination of high soil N supply, warm and wet soil conditions, and cover crop decomposition contributes to elevated N2O emissions, but the cumulative effects of side-dress N application with a CR cover crop are variable across years. With increasing adoption of these practices to reduce nitrate leaching losses from croplands, future work should simultaneously assess effects on N2O emissions and crop yield to account for potential tradeoffs in N loss pathways.
Chaperon, Pascal N.Rodriguez-San Pedro, AnniaBeltran, Clemente A.Allendes, Juan Luis...
9页
查看更多>>摘要：Bat populations are threatened in many regions of the world, partly due to the loss of foraging and commuting habitats in farmland and declines in insect prey populations caused by agricultural intensification. Given that bats play an important role as bioindicators and in suppressing crop pests, it is crucial to mitigate negative impacts that arise from these threats. In this study we evaluated the richness, quantified at family level, and abundance of bat prey insects in organic vineyards surrounded by three types of adjacent habitat: urban/semiurban areas, exotic tree plantations, and remnants of native vegetation. The relationship between the abundance of prey and the foraging activity of bats in the vineyards was also examined. Insects were sampled using ultraviolet light traps, located both inside and at the edge of the vineyards. Bat activity was monitored at each site using acoustic recorders. The insect richness was unaffected by the type of adjacent habitat and did not differ between the edge and the interior of the vineyards. In contrast, insect abundance was significantly influenced by the type of adjacent habitat. Vineyards adjacent to native vegetation and exotic tree plantations showed the highest abundances for most insect orders present in the bat diet compared to urban areas. Bat activity was significantly correlated with the abundance of Coleoptera and Lepidoptera, with mixed effects between bat species (negative for Tadarida brasiliensis, positive for Lasiurus varius, Lasiurus villosissimus and Myotis chiloensis). Crop edges adjacent to native vegetation provides important foraging habitat for bats and should therefore be considered in agricultural management. Locating vineyards close to these habitats may promote bat conservation via increased prey insects and may also benefit winegrowers through the ecosystem services provided by insectivorous bats in this crop.
查看更多>>摘要：Agricultural landscapes are characterized by a variety of habitats resulting from man-made transformations of the natural environment. Progressing agricultural intensification is leading to a reduction in natural and semi natural habitats, resulting in turn in a loss of biodiversity. In farmland, natural habitats such as field margins, hedgerows, and meadows are progressively declining or being transformed. There is a need for regionally adjusted schemes that balance agricultural production and biodiversity conservation due to strong differences even within one country. We present a potential tool that can mitigate biodiversity loss in farmland ecosystems. In this study, we compared transects on three different habitat types: unused railway lines, dirt road verges and fields in terms of overall, farmland and open land bird species abundance, richness and Shannon-Wiener diversity index as well as community composition in intensively managed agricultural landscapes. We predicted that 1) bird abundance, species richness and diversity would be greater in vegetation structure along unused railway lines due to their spontaneous vegetation character than in other habitats, and 2) bird community composition would be different between three habitat types (unused railway lines, farmland roads and transects in farming areas). Our findings demonstrated that habitats along unused railway lines provide a suitable environment for farmland birds, increasing bird diversity in the agricultural landscape and playing a wider role in biodiversity conservation. Vegetation structures along unused railway lines may act as alternative refuges for birds in each season, providing food resources, nesting, shelter, perching, singing, and resting sites as well as constitute a kind of ecological corridor running within an intensively used agricultural landscape.
NSTL
Elsevier