Supporting populations of organisms that provide pollination and biological pest control is a key component of ecological intensification to promote sustainable agriculture. Because insect pollinators and natural enemies share certain habitat needs, scenarios that benefit both may depend on spatio-temporal congruence of these habitats and the relative mobilities of the different organisms. Most studies that document landscape effects on such mobile ecosystem providers have focused on one group or the other. Furthermore studies find that landscape context can interact with on-farm agronomic practices to determine the direction and magnitude of outcomes for pollination and pest control services, as well as the organisms that provide them.
We used spatially explicit models of pollinators and natural enemies to predict the delivery of pollination and pest control across landscape configurations (grain size) and contrasting crop management strategies (till versus no-till). The framework merges previously-published process models of pollinators and natural enemies, respectively, which predict service delivery based on specific crop and non-crop habitat qualities and organism mobility. We use the framework to identify potential landscape scenarios and specific actions that co-benefit services versus scenarios that reduce one or the other leading to a service disservice trade-offs.
Results/Conclusions
Crop management interacted with landscape configuration to affect on-crop pollinator abundance. In simple (coarse-grained) landscapes crop management produced contrasting outcomes with pollinator abundance much greater on no-till than till fields. This occurs because tilling prevents bees from nesting within crop fields, thus they must fly from natural habitat to provide pollination. In complex (fine-grained) landscapes natural habitats were generally closer to all parts of the crop so tillage mattered less. Natural enemies responses were more consistent across landscape configuration although they were generally more abundant in no-till fields. Highly mobile natural enemies responded more similarly to pollinators, than those with limited mobility. The importance of landscape complexity for providing co-benefits to pollination and pest control was clearest for tilled fields. Pollinators and natural enemies both benefited from increased complexity. However the potential for co-benefits on no-till fields was inconsistent and depended on the relative mobilities of natural enemies and pollinators. At one extreme, increasing complexity produced potential trade-offs between pollinators and low-mobility natural enemies. Our models highlight the interplay of local and landscape factors in determining multiple ecosystem services. Strategies to promote multiple services will benefit from understanding the congruence of habitat needs and mobility of service-providing organisms.