Conference Agenda

Agri-environment schemes have been the main policy tool to enhance farmland biodiversity within the Common Agricultural Policy of the European Union. However, the efficacy of these schemes has varied. One reason could be that the multiple goals of agri-environment schemes are not considered, such that it may be better to separately consider general conservation goals and support of biodiversity-based ecosystem services. We have shown that this may entail spatial targeting of different interventions, related to their marginal benefits and the spatial scales relevant for underlying ecological mechanisms. However, applying these general principles on biological pest control is complex and highly context-dependent. Given the current policy push to significantly reduce the use of pesticides in the EU, enhancing biological pest control in structurally simple, productive landscapes will become increasingly important. Improved predictability of natural pest control, and a better understanding of the role of increasing crop diversity can significantly contribute to the success of this policy transition.

Agricultural intensification has led to a loss of biodiversity and associated ecosystem services such as natural pest control. Conservation biological control (CBC) addresses this problem by providing alternative habitats and food sources for natural enemies of pest species and/or through a general extensification of the orchard management (e.g., reduced agrochemical input, less disturbance). However, these measures are rarely implemented by farmers due to the wide range of options with inconsistent effects. We conducted hierarchical meta-analyses to identify general patterns of local CBC interventions in relation to (i) insect pest abundance, (ii) natural enemy abundance, (iii) biological control, and (iv) fruit quality in apple orchards. Across 54 studies, we found an overall significant, positive effect of local interventions on natural enemy abundance. Among our established intervention categories - flower resources, ground covers, extensification - ground covers promoted natural enemies the most, especially predators. Furthermore, ground covers tended to reduce the density of pest insect. Similarly, flowering components promoted natural enemies, especially parasitoids, and showed no negative effects on fruit quality. In contrast, extensification of orchard management alone had no significant effect on the abundance of natural enemies, but showed a tendency to increase populations of pest insects and reduce fruit quality.

Agricultural intensification, with high agrochemical input and landscape simplification, poses a major threat to wildlife. At the same time, natural pest control can greatly contribute to biodiversity conservation and agricultural production. In our study, we examined the effects of birds and bats on grapevine pests and their pest control service using experimental field exclosures in 12 Hungarian vineyards, considering vineyard management and deciduous forest proximity. We found that insectivorous bird abundance and bat activity in spring were positively affected by forest proximity, whereas grape eater bird abundance and bat activity in summer showed an opposite pattern. The abundance of canopy-dwelling arthropods (herbivores and predators) was higher in organic vineyards than in conventional ones, which resulted in higher leaf herbivory and higher sentinel prey predation there. In addition, grape plant exclusion positively affected leaf herbivory and fruit damage, showing the biocontrol service of birds and bats. Furthermore, leaf herbivory and fruit damage increased with increasing abundance of leaf herbivores and moths, respectively. Considering the functional relationships, moth abundance decreased with higher bat activity in spring. Ultimately, our results showcase that bats can reduce fruit damage in vineyards by regulating grapevine moth populations, especially at the beginning of the growing season.

Local edaphoclimatic factors, viticultural practices, and landscape composition significantly influence ecosystem services and biodiversity within vineyards. Pest control by natural enemies is a crucial ecosystem service in viticulture, contributing to current pesticide reduction goals of the EU in one of the most pesticide-dependent land use types.

We investigated the effects of different inter-row tillage intensities, cover crop types, pesticide use and proportion of semi-natural habitats on biodiversity and ecosystem services within five European wine-growing regions. These field data were combined with a global meta-analysis analysing the effects of pesticide use, farming type, vegetation management and landscape composition on biodiversity and ecosystem service provision.

Natural pest control by predatory mites and other natural enemies in vineyards benefited from reduced pesticide use and spontaneous vegetation cover in the inter-rows. In organic vineyards higher use of inorganic fungicides resulted in higher toxicity loadings for predatory mites and other arthropods. The global meta-analysis resulted in positive effects of vegetated vineyard inter-rows and organic management with especially large benefits for biodiversity and regulating ecosystem services. In addition, biological control benefited from larger proportions of semi-natural habitats and biodiversity from lower proportions of agricultural land cover.

Managing agricultural landscapes to support biodiversity and natural pest control could be a key avenue towards sustainable and climate-resilient agriculture that works for farmers. However, precisely how to manage these landscapes – and how effective this will be - is unclear. I briefly review the results of recent syntheses that show the importance of local and landscape parameters for maintaining or enhancing arthropod biodiversity and ecosystem services including pest control. These include the amount of habitat and crops in farmed landscapes, but also their compositional and configurational heterogeneity, spatiotemporal patterns of crop rotations, and neighbourhood effects. These studies show that these parameters can act synergistically, and that separating species according to dietary, dispersal and overwintering traits leads to contrasting responses. Based on these results, I describe how the development of archetypes formed from key combinations of species’ traits can inform predictive models of natural pest control potential anticipating the impacts of landscape- and field-scale management, towards a workable ecological intensification of agricultural production under global change.

Although most agricultural landscapes are principally managed to maximize food provisioning, they can also provide a large array of supporting and regulating ecosystem services. Biological control, in particular, is one of the most studied services and a large body of literature has investigated its local and landscape drivers. However, we do not know yet whether managing landscapes for improving biocontrol could also generate other environmental co-benefits. Compared to crop-dominated landscapes, heterogeneous landscapes are expected to provide better biocontrol but also high delivery of multiple services. Here, we empirically measured multiple ecosystem services (plant and pollinator diversity, pest and seed predation, and several below-ground services) in different habitats across a landscape composition gradient and tested for potential trade-offs and synergies between services. At the local scale, relationships between services were complex and often context-dependent. We found a positive correlation between weed and pest predation in semi-natural habitats but not within crops. High levels of weed and pest predation were not associated with plant and pollinator diversity nor with the delivery of other services. Synergies were generally rare. Except for the expected positive association between plant and pollinator diversity, we mostly observed idiosyncratic relationships among services.