Biodiversity and associated ecosystem services in small vs. large scale agriculture

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Biodiversity conservation cannot rely on protected areas alone, as sustainable conservation requires strategies for managing whole landscapes including agricultural areas. To address this challenge, a framework has been proposed that distinguishes between the integration ("land sharing") and separation ("land sparing") of conservation and production. These two conceptualisations have resulted in one of the largest controversies in current conservation biology, termed the land sparing vs. land sharing debate. Land sparing strategy argues for agricultural intensification outside natural habitats, since a high percentage of wild species cannot survive in even the most wildlife-friendly farming systems, making protection of wild land essential. Land sharing strategy argues that there might be situations, where high biodiversity can be coupled with high yield. Putting this whole debate completely in agricultural areas, such as intensive arable agriculture, flower strips (FS) implemented in edges of arable fields represent the land sparing strategy, whereas organic farming represents the land sharing strategy. Therefore, in the proposed project, I will test the idea that farmland biodiversity and associated services differ between a land-sharing vs. land-sparing strategy, which can be applied at local and landscape scales. I hypothesize that local land sharing such as the previously studied organic management is less important than local land sparing with the separation of land via a FS. However, upscaling this to farm level, organic farming will turn to be more important than conventional farming with a few FS due to its much higher cover. I also hypothesize that effectiveness of agri-environment schemes is higher under landscape-wide land sparing with large crop fields than in landscape-wide land sharing with small fields, and under decreasing landscape-wide cover of organic management. Therefore, pairs of organic and conventional farms will be selected in small to large scale agricultural landscapes and along an orthogonal gradient of organic land cover. From each organic farm two winter wheat fields will be selected, whereas from each conventional farm four winter wheat fields will be selected, two with FS and two without FS. I plan to measure the diversity of plants and arthropods and associated ecosystem services, such as insect predation, aphid parasitism and pollination. Furthermore, I plan to study how these two strategies affect to food diversity and foraging time of exposed Bombus terrestris colonies, and body size of wild bumblebees both at local and landscape scales.