Enhancing ecosystem services through green infrastructure in agricultural landscapes (ECODEAL)

Ecological intensification relies on ecosystem services to substitute external inputs in agriculture and has been proposed as a way to achieve high yielding, stable and sustainable crop production, while allowing us to reach other societal targets such as nature conservation. Pollination and natural pest control are key ecosystem services that can lower pesticide use and increase crop yield quantity and quality. Organisms delivering these services depend to a large extent on non-crop habitats, or "green infrastructure" in the landscape, as cropland is not well suited as a habitat all year round. ECODEAL is a European research project assessing the impacts of green infrastructure on the delivery of ecosystem services and consequences for individual farmers and the whole society. How much green infrastructure do we need to maintain stable communities of ecosystem service providers, and a high flow and stability of the services to the crop? Since establishing non-crop habitat comes at a cost, which densities of green infrastructure will enhance crop yield and populations of conservation relevant species while providing net increases in crop productivity as well as net economic benefits to the farmer? ECODEAL will answer these questions. A sound scientific basis now links increased densities of different elements of green infrastructure in the landscape result to increased local biodiversity. Further work is needed to understand how increases in green infrastructure at different scales can be translated to benefits in terms of enhanced crop production, in particular in a context in which variability in climate and agricultural prices will differentially affect crop growth, the populations of pests and beneficial organisms, and the costs of converting productive land to green infrastructure. ECODEAL will (1) quantify increases in crop productivity mediated by pollination and natural pest control under different densities of agricultural non-crop habitats at different scales, as an essential step towards assessing costs and benefits of enhancing the density of green infrastructure (2) disentangle the linkages between density of green infrastructure and the structure and stability of the interaction networks linking the crop and the non-crop habitats communities over multiple years, and (3) quantify possible trade-offs between enhancing green infrastructure for ecological intensification of agriculture as opposed to supporting conservation-relevant species. ECODEAL synthesizes large existing databases to model the relationship between density of green infrastructure and the distributions of functional traits and the structure of the ecological interaction networks that underlie pollination and natural pest control. Cases studies from established study area covering economically important field crops will be used to fill the gaps in the existing data. These data will be used to validate and update the ecosystem service models derived from the synthesis work. Cooperation with land owners and managers, institutions and organisations designing and implementing agri-environment schemes, advising farmers, managing protected areas, and developing agricultural and environmental policy, ensures that the ECODEAL assessment of the question "how much green infrastructure do we need for enhanced, stable ecosystem services in crops?" finds ownership among key stakeholders.

ECODEAL stands for Enhancing biodiversity-based ecosystem services to crops through optimized densities of green infrastructure in agricultural landscapes. Green infrastructure are elements of the landscape, or arrangements of elements in the landscape, that support a diversity of species, including those species that support the pollination of crops and wild plants, and the natural control of pests. Within the project (1) we analysed existing data to refine our understanding of the links between how we use the land, the diversity and composition of communities of pest and beneficial organisms arthropod, and the ecosystem services (2) we conducted core landscape-scale fieldwork in Germany France and the Netherlands, to fill gaps in our knowledge on both the ecological and the economic aspects of these relationships (3) we developed spatially explicit ecosystem service models that allow us to predict form a map of a region where ecosystem services are weak and where they are strong, and what could be done to improve them (4) developed ecological-economic models that we combined with management scenarios to quantify the trade-offs between different services and the economic impacts for the farmers. A major finding of ECODEAL is that when considering ecosystem services to crops the concept of green infrastructure needs to be broadened to include not only the presence of uncultivated areas in the landscapes, but also small scale mosaics of arable fields, for which suitable indicators are landscape-scale field size or field edge density. Indeed, small fields/large edge density strongly support biodiversity, pollination and pest control. In landscapes with large fields, farmers can rely less on natures services to support agricultural production. This is very significant because as we found in ECODEAL the contribution of pollinators to yield of field crops, and the contribution of natural enemies to the control of pests, can be very important. We identify several challenges in adapting agricultural landscapes for improved ecosystem services to crops. The economic value of individual ecosystem services is significant in absolute terms, however the size of the effects can vary a lot between regions and varieties. Under current conditions, increases in yield in pollinator-dependent crops, as well as increases in natural enemies are not always economically attractive enough to motivate interventions at the landscape scale that are costly. Agri-environmental measures and ecological focus areas, are not generally seen as an opportunity to support ecosystem services to crops, suggesting information and framing could be much improved.