Reconciling food production and biodiversity conservation in Europe

Food security and the ongoing loss of biodiversity are two of this century's greatest challenges. Recent modeling work shows that identifying how best to meet rising food demand at lowest cost to other species requires information on how their populations respond to changes in agricultural yield. Only two studies have so far collected such data. This project will be the first to do so in Europe, and will thereby generate urgently needed information which the CASE partner, BirdLife International (a global partnership of national conservation organisations with representatives in 42 European countries, including all EU Member States, and a European Secretariat in Brussels), can use to guide ongoing reforms of European agricultural and conservation policy. Two divergent solutions have been proposed for addressing the conflict between food production and biodiversity conservation. Wildlife-friendly farming (WFF) involves making farmland itself as beneficial to wildlife as possible. Land-sparing (LS), on the other hand, stems from concerns that WFF usually lowers farm yields and so requires more land under farming: LS instead proposes increasing yield on existing farmland and thereby sparing remaining habitat from conversion (or freeing redundant farmland for habitat restoration). Early results from two tropical studies indicate that most species there would do best under LS. In Europe, however, agri-environment subsidies encourage WFF. This latter approach might be justified if strong selection from exposure to past glaciation and millennia of agriculture mean that surviving European species are less sensitive to farming - but to date no studies have tested this idea by quantifying how population densities of a wide range of European species respond to variation in yield. This project will fill that gap. Working in Poland - which offers an exceptional range of farming systems as well as some of Europe's most intact habitats - the student will measure population densities of all species of birds, butterflies and trees across 25 study sites, ranging from unmodified forest and wetland through to high-yield farming. By quantifying gross and agricultural yields for the same sites the student will characterise how each species responds to increasing yield. These density-yield curves can then be compared to test whether resident European species are indeed less sensitive to disturbance than migratory or tropical species. To evaluate which approach would allow most species to persist the student will then work with Polish collaborators to generate plausible scenarios of how demand for food production might change by 2050, and compare the consequences for species' viability of meeting those demands under either LS or WFF. Last, the student will use the output of the scenarios to design choice experiments to establish which approach people would prefer - and thereby explore whether there is a conflict between the cultural and biodiversity values of these alternative solutions. The strong track record of the CASE partner as well as that of that of our collaborators in RSPB and OTOP (its Polish equivalent) will ensure the results of the study are used as effectively as possible to inform European farming and conservation policy at both EU and national level. By providing the first temperate assessment of species' density-yield curves the project will also add significantly to our understanding of global patterns of species' sensitivity to land use change.