Biodiversity conservation on farmland: start at the landscape level

For decades, policy makers, NGO’s, companies in the agro-production chain and farmers are struggling to improve biodiversity in Europe’s countryside. Most efforts focus on individual farms. However, we know that in biodiversity conservation the landscape level is highly relevant. Basic conditions like the area of non-cultivated land are of major importance for most species groups. Just like the close proximity of nature areas. The EU proposed in its Common Agricultural Policy that 3–7% of EU farmland should be managed as Ecological Focus Area in order to halt biodiversity loss. We empirically assessed the implications of this policy by evaluating the effects of the density of natural elements in the agricultural landscapes of The Netherlands on multi-taxon species richness, including vascular plants, breeding birds, butterflies, hoverflies, dragonflies, and grasshoppers. We found that species richness increased as a function of the proportion of natural elements in the landscape. Even landscapes with 3–7% of natural elements harboured generally 37–75% of maximum species richness. However, differences between the 3 and 7% limits were considerable for butterflies, birds, and hoverflies. To improve biodiversity it is necessary to develop tailor-made approaches at regional levels, including all relevant stakeholders.