Farm size matters: A spatially explicit ecological-economic framework for biodiversity and pest management

The intensification of European agriculture, characterized by increasing farm sizes, landscape simplification and reliance on synthetic pesticides, remains a key driver of biodiversity decline. While many studies have investigated this phenomenon, they often focus on isolated elements, resulting in a lack of holistic understanding and leaving policymakers and farmers with unclear priorities. This study addresses this gap by developing a spatially explicit ecological economic model designed to dissect the complex interplay between landscape structure and pesticide application, and their combined effects on natural enemy populations and farmers' economic returns. In particular, the model investigates how these relationships are modulated by farm size - a crucial aspect frequently overlooked in prior research. By calibrating on the European agricultural sector, we explore the ecological and economic consequences of various policy scenarios. We show that the effectiveness of ecological restoration strategies is strongly contingent upon farm size. Small to medium-sized farms can experience economic benefits from reduced pesticide use when coupled with hedgerow restoration, owing to enhanced natural pest control. In contrast, large farms encounter challenges in achieving comparable economic gains due to inherent landscape characteristics. This highlights the need to account for farm size in agri-environmental policies in order to promote biodiversity conservation and agricultural sustainability.