Mapping agrobiodiversity in Europe: Different indicators, different priority areas

•Existing spatial agrobiodiversity indicators overlap in only few EU locations.•Low agrobiodiversity areas are more correlated than agrobiodiversity hotspots.•The indicators’ response to land use change scenarios is highly variable.•Indicator choice may cause divergent research results and affect conservation plans. Agriculture plays a dual role in the conservation of European biodiversity, as extensive agricultural lands provide habitats for more than half of Europe's species, but intensification and abandonment of farmland threaten these species' habitats. Consequently, the preservation of agrobiodiversity, i.e., biodiversity on agricultural land, is increasingly the focus of conservation strategies. Agrobiodiversity is a complex and multi-dimensional concept, which begets that there currently is no consistent definition, measurement framework, or high-resolution spatial indicator that covers all facets of agrobiodiversity (genetic, species, and ecosystem). Furthermore, existing indicators have not been compared in terms of the areas the indicators identify as having high agrobiodiversity value. The objective of this study was, therefore, to compare four agrobiodiversity indicators, representing species and ecosystem levels of agrobiodiversity, by mapping them on extensive agricultural land in Europe and comparing them with the High Nature Value Farmland (HNVF) map. We mapped hotspots for each indicator and performed a pairwise Fuzzy Numerical map comparison. The findings show only moderate spatial similarity between indicators, where similarities mainly reflect correspondence in coldspot areas as well as low hotspot agreement with the well-established HNVF map. The results further indicate correspondence between hotspots for all indicators and HNVF on less than 1,500 km2 (or less than 0.005% of extensive European farmland). The indicators' sensitivity to land-use change scenarios was also evaluated, revealing up to ± 50% difference in scenario response, depending on the chosen indicator, which could lead to inconsistent scenario outcomes. The results of this novel study highlight the importance of clearly defining agrobiodiversity before mapping and selecting an indicator for measuring it, especially if such analysis intends to identify priority areas for policy targeting.