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The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies.

Water deficit and water excess constitute severe stresses that limit crop yield and are likely to intensify as climate becomes more variable. Regional crop production aggregates for the US Midwest indicate widespread yield losses in past decades due to both extreme rainfall and water limited conditions, though the degree to which these weather impacts are related to site-specific factors such as landscape position and soils has not been examined in a systematic manner. This study offers observational evidence from a large sample of commercial crop fields to support the hypothesis that landscape position is the primary mediator of crop yield responses to weather within unstable field zones (i.e., zones where yields tend to fluctuate between high and low, depending on the year). Results indicate that yield losses in unstable zones driven by water excess and deficits occur throughout a wide range of seasonal rainfall, even simultaneously under normal weather. Field areas prone to water stress are shown to lag as much as 23–33% below the field average during drought years and 26–33% during deluge years. By combining large-scale spatial datasets, we identify 2.65 million hectares of water-stress prone cropland, and estimate an aggregated economic loss impact of $536M USD yr-1, 4.0 million tons yr-1 of less CO2 fixed in crop biomass, and 52.6 Gg yr-1 of more reactive N in the environment. Yield stability maps can be used to spatially implement adaptation practices to mitigate weather-induced stresses in the most vulnerable cropland

1. A substantial proportion of the global land surface is used for agricultural production. Agricultural land serves multiple societal purposes; it provides food, fuel and fibre and also acts as habitat for organisms and supports the services they provide. Biodiversity conservation and food production need to be balanced: production needs to be sustainable, while conservation cannot be totally at the expense of crop yield. 2. To identify the benefits (in terms of biodiversity conservation) and costs (in terms of reduction in yields) of agricultural management, we examined the relationship between crop yield and abundance and species density of important taxa in winter cereal fields on both organic and conventional farms in lowland England. 3. Of eight species groups examined, five (farmland plants, bumblebees, butterflies, solitary bees and epigeal arthropods) were negatively associated with crop yield, but the shape of this relationship varied between taxa. It was linear for the abundance of bumblebees and species density of butterflies, concave up for the abundance of epigeal arthropods and butterflies and concave down for species density of plants and bumblebees. 4. Grain production per unit area was 54% lower in organic compared with conventional fields. When controlling for yield, diversity of bumblebees, butterflies, hoverflies and epigeal arthropods did not differ between farming systems, indicating that observed differences in biodiversity between organic and conventional fields are explained by lower yields in organic fields and not by different management practices per se. Only percentage cover and species density of plants were increased by organic field management after controlling for yield. The abundance of solitary wild bees and hoverflies was increased in landscapes with high amount of organic land. 5. Synthesis and applications. Our results indicate that considerable gains in biodiversity require roughly proportionate reductions in yield in highly productive agricultural systems. They suggest that conservation efforts may be more cost effective in low-productivity agricultural systems or on non-agricultural land. In less productive agricultural landscapes, biodiversity benefit can be gained by concentrating organic farms into hotspots without a commensurate reduction in yield.

In this four-year transdisciplinary study, we assess the contribution of three activities in a food hub (FH) in the form of a living lab to the transformation of the agri-food system of the Berlin-Brandenburg city-region: food delivery from community-supported agriculture (CSA) farms, community dinners in the FH, and food rescuing. We followed, first, a reflexive approach to assess the FH activities’ contribution to the food system transformation: we monitored the flow of all food that arrive at the FH in the three activities. Second, we followed a transformative approach in order to assess how the FH can be scaled (deep, out, and up) to the whole city-region. A multi-method approach based on citizen science principles and applied participatory methods was used to co-design and co-develop the reflexive phase, as well as to co-create the solutions in the following transformative phase considering different actors of the food system. The empirical phase was affected by COVID19-related restrictions, but direct interactions between the actors in a living lab setting were still possible in compliance with hygiene regulations. We found that the CSA deliveries and community dinners were the most impactful activities. The CSA deliveries could already be contributing to meet 50% of current demand of vegetable consumption. We propose a season calendar of regional and seasonal products based on the results from monitoring the CSA deliveries. By combining them with the monitoring of the menus of community dinners, we also propose an increase in the production of specific, relevant products to foster the adoption of sustainable and healthy diets in the region. Overall, we found that the transformative impact of the FH is due to the fact that it is a space that challenges existing power structures, fostering the creation of new visions and shared meaning that deviate from the globalized and conventional agri-food system. We also found that the living lab approach is of key importance for the creation of social-ecological knowledge as the basis for improving the FH activities (deep-scaling). Nevertheless, the multi-method approach allowed us to find that there was still room for taking advantage of the full potential of the FH as a space for social-ecological learning in order to increase its transformative impact. Doing this and scaling the FH concept (LebensMittelPunkt) to the whole city and city-region would contribute to the creation of an agroecology-based territorialized agri-food system. To our knowledge, this is the first study assessing an urban-placed and agroecology-based initiative applying the living lab core characteristics to increase its transformative social-ecological impact. This study could serve to other researchers working with living labs in developing social-ecological transformative solutions.

Ecosystem services to agriculture, such as pollination, rely on natural areas adjacent to farmland to support organisms that provide services. Native insect pollinators depend on natural or semi‐natural land surrounding farms for nesting and alternative foraging resources. Despite interest in conserving pollinators through habitat restoration, the scale at which land use affects pollinators and thus crop pollination services is not well understood. We measured abundance of native, wild bee pollinators and the pollination services they provided to highbush blueberry Vaccinium corymbosum L. crops at 16 sites that varied in the proportion of surrounding agricultural land cover at both the field scale (300‐m radius) and the landscape scale (1500‐m radius). We designed our study such that agricultural land cover at the field scale was uncorrelated with agricultural cover at the landscape scale across sites. We used model selection to determine which spatial scale better predicted aggregate bee abundance, abundance of large versus small bees and crop pollination services. We found that, overall, bees responded more strongly to field‐scale than to landscape‐scale land cover, but the scale at which land cover had the strongest effect varied by bee body size. Large bees showed a negative response to increasing agricultural cover at both scales, but were most strongly affected by the landscape scale. Small bees were negatively affected by agricultural land cover but only at the field scale, while they had a small positive response to agricultural cover at the landscape scale. Aggregate pollination services from native bees were more strongly influenced by field‐scale agricultural cover, due to the combined effects of both large and small bees responding at that scale. Synthesis and applications. Bee abundance and pollination services were strongly determined by field‐scale agricultural cover, suggesting that field‐scale set‐asides may provide significant benefits to pollination services. Further, we found that pollinators respond differently to land use depending on body size, but all groups of bees benefit from decreasing agricultural cover at the field scale. Therefore, small‐scale modifications to habitat can have significant impacts on both pollinator abundance and pollination services to crop plants.

We examine the potential role of perennial woody food-producing species (“food trees”) in cities in the context of urban sustainable development and propose a multifunctional approach that combines elements of urban agriculture, urban forestry, and agroforestry into what we call “urban food forestry” (UFF). We used four approaches at different scales to gauge the potential of UFF to enhance urban sustainability and contribute to food security in the context of urbanization and climate change. First, we identified 37 current initiatives based around urban food trees, and analyzed their activities in three categories: planting, mapping, and harvesting, finding that the majority (73 %) only performed one activity, and only 8 % performed all three. Second, we analyzed 30 urban forestry master plans, finding that only 13 % included human food security among their objectives, while 77 % included habitat for wildlife. Third, we used Burlington, Vermont as a case study to quantify the potential fruit yield of publicly accessible open space if planted with Malus domestica (the common apple) under nine different planting and yield scenarios. We found that 108 % of the daily recommended minimum intake of fruit for the entire city’s population could be met under the most ambitious planting scenario, with substantial potential to contribute to food security even under more modest scenarios. Finally, we developed a Climate–Food–Species Matrix of potential food trees appropriate for temperate urban environments as a decision-making tool. We identified a total of 70 species, 30 of which we deemed “highly suitable” for urban food forestry based on their cold hardiness, drought tolerance, and edibility. We conclude that substantial untapped potential exists for urban food forestry to contribute to urban sustainability via increased food security and landscape multifunctionality.

In the US Corn Belt, a recent doubling in commodity prices has created incentives for landowners to convert grassland to corn and soybean cropping. Here, we use land cover data from the National Agricultural Statistics Service Cropland Data Layer to assess grassland conversion from 2006 to 2011 in the Western Corn Belt (WCB): five states including North Dakota, South Dakota, Nebraska, Minnesota, and Iowa. Our analysis identifies areas with elevated rates of grass-to-corn/soy conversion (1.0–5.4% annually). Across the WCB, we found a net decline in grass-dominated land cover totaling nearly 530,000 ha. With respect to agronomic attributes of lands undergoing grassland conversion, corn/soy production is expanding onto marginal lands characterized by high erosion risk and vulnerability to drought. Grassland conversion is also concentrated in close proximity to wetlands, posing a threat to waterfowl breeding in the Prairie Pothole Region. Longer-term land cover trends from North Dakota and Iowa indicate that recent grassland conversion represents a persistent shift in land use rather than short-term variability in crop rotation patterns. Our results show that the WCB is rapidly moving down a pathway of increased corn and soybean cultivation. As a result, the window of opportunity for realizing the benefits of a biofuel industry based on perennial bioenergy crops, rather than corn ethanol and soy biodiesel, may be closing in the WCB.

1. Two strategies are often promoted to mitigate the effects of agricultural expansion on biodiversity: one integrates wildlife-friendly habitats within farmland (land sharing), and the other intensifies farming to allow the offset of natural reserves (land sparing). Their relative merits for biodiversity protection have been subject to much debate, but no previous study has examined whether trade-offs between the two strategies depend on the proximity of farmed areas to large tracts of natural habitat. 2. We sampled birds and dung beetles across contiguous forests and agricultural landscapes (low-intensity cattle farming) in a threatened hotspot of endemism: the Colombian Chocó-Andes. We test the hypothesis that the relative biodiversity benefits of either strategy depend partially on the degree to which farmlands are isolated from large contiguous blocks of forest. 3. We show that distance from forest mediates the occurrence of many species within farmland. For the majority of species, occurrence on farmland depends on both isolation from forest and the proportionate cover of small-scale wildlife-friendly habitats within the farm landscape, with both variables having a similar overall magnitude of effect on occurrence probabilities. 4. Simulations suggest that the biodiversity benefits of land sharing decline significantly with increasing distance from forest, but land sparing benefits remain consistent. In farm management units situated close to large contiguous forest (<500 m), land sharing is predicted to provide equal benefits to land sparing, but land sparing becomes increasingly superior in management units situated further from forest (1500 m). The predicted biodiversity benefits of land sparing are similar across all distances, provided that sparing mechanisms genuinely deliver protection for contiguous forest tracts. 5. Synthesis and applications. The persistence of bird and dung beetle communities in low-intensity pastoral agriculture is strongly linked to the proximity of surrounding contiguous forests. Land-sharing policies that promote the integration of small-scale wildlife-friendly habitats might be of limited benefit without simultaneous measures to protect larger blocks of natural habitat, which could be achieved via land-sparing practices. Policymakers should carefully consider the extent and distribution of remaining contiguous natural habitats when designing agri-environment schemes in the tropics.

1. Cover crop mixtures with complementary plant functional traits including biological nitrogen fixation (BNF) may supply nitrogen (N) to farm fields while simultaneously providing other ecosystem functions such as N retention and weed suppression (i.e., multifunctionality). Understanding variation in these relationships across farms can help advance trait-based research in agroecology and ecological approaches to nutrient management. 2. This on-farm experiment explored the contributions of two- and three-species cover crop mixtures, which combined legumes, brassicas and cool season grasses, to ecosystem functions across a gradient of soil fertility levels driven by farm management history. 3. I evaluated the predictions that functional trait diversity of the cover crops would explain variation in multifunctionality, and that legume biomass and BNF within mixtures would be inversely correlated with indicators of soil N availability from organic matter across the farm gradient. 4. Ecosystem functions varied widely across farms. As expected, functional diversity was a significant predictor of multifunctionality, although the relationship was weak. Cover crop mixtures had significantly greater multifunctionality than a cereal rye monoculture, though not at the highest observed levels of each function, indicating trade-offs among functions. Linear regression models showed that legume biomass and BNF were negatively correlated with soil properties indicative of N availability from soil organic matter, whereas non-legume and weed biomass were positively correlated with other measures of soil fertility. 5. Synthesis and applications. Cover crop mixtures can increase functional diversity within crop rotations. Designing mixtures with complementary plant traits may be particularly effective for increasing multifunctionality and agroecosystem sustainability. On-farm research to understand variation in biological nitrogen fixation, which is both a plant trait and a key ecosystem function, across heterogeneous soil conditions, can inform management of soil fertility based on ecological principles.