Disentangling direct and indirect drivers of farmland biodiversity at landscape scale

Abstract

To stop the ongoing decline of farmland biodiversity there are increasing claims for a paradigm shift in agriculture, namely from conserving and restoring farmland biodiversity at field scale (α‐diversity) to doing it at landscape scale (γ‐diversity). However, knowledge on factors driving farmland γ‐diversity is currently limited. Here, we quantified farmland γ‐diversity in 123 landscapes and analysed direct and indirect effects of abiotic and land‐use factors shaping it using structural equation models. The direction and strength of effects of factors shaping γ‐diversity were only partially consistent with what is known about factors shaping α‐diversity, and indirect effects were often stronger than direct effects or even opposite. Thus, relationships between factors shaping α‐diversity cannot simply be up‐scaled to γ‐diversity, and also indirect effects should no longer be neglected. Finally, we show that local mitigation measures benefit farmland γ‐diversity at landscape scale and are therefore a useful tool for designing biodiversity‐friendly landscapes.

Abstract

To stop the ongoing decline of farmland biodiversity there are increasing claims for a paradigm shift in agriculture, namely from conserving and restoring farmland biodiversity at the field scale (α‐diversity) to doing it at the landscape scale (γ‐diversity). By analysing 123 landscapes with structural equation models, this study demonstrates that the relationships between factors shaping α‐diversity cannot simply be up‐scaled to γ‐diversity, and that also indirect effects should taken into account when designing biodiversity‐friendly landscapes.