Importance of set-aside for breeding birds of open farmland in Finland

The set-aside obligation under the Common Agricultural Policy (CAP) brought widespread benefits for wild farmland species. Shortly after it was abolished in 2008, the national political process in Finland replaced it with a targeted agri-environment scheme for environmental fallow. Though potentially highly valuable, the value of the current scheme for securing biodiversity is yet to be confirmed. This study evaluates the importance of set-asides established under CAP to all birds of open farmland based on national monitoring data from 2001 to 2006. The set-aside fields supported 25-40% more species and held 60-105% more pairs of birds typical of open farmland in comparison with cereal fields within a similar landscape setting. The estimated effect of set-aside presence in farmland on the studied bird species is large enough to trigger considerable changes in bird populations on the national scale. The relevance of the results to the novel agri-environment scheme is discussed.