Agri-environment schemes do not effectively protect biodiversity in Dutch agricultural landscapes

Roughly 20% of the European Union's farmland is under some form of agri-env ironment scheme to counteract the negative impacts of modern agriculture on the environment 1. The associated costs represent about 4% (1.7 billion eu ros) of the European Union's total expenditure on the Common Agricultural P olicy and are expected to rise to 10% in the near future(2). Although agri- environment schemes have been implemented in various countries for well ove r a decade, to date no reliable, sufficiently replicated studies have been performed to test whether such measures have the presumed positive effects on biodiversity(1,3,4). Here we present the results of a study evaluating t he contribution of agri-environment schemes to the protection of biodiversi ty in intensively used Dutch agricultural landscapes. We surveyed plants, b irds, hover flies and bees on 78 paired fields that either had agri-environ ment schemes in the form of management agreements or were managed conventio nally. Management agreements were not effective in protecting the species r ichness of the investigated species groups: no positive effects on plant an d bird species diversity were found. The four most common wader species wer e observed even less frequently on fields with management agreements. By co ntrast, hover flies and bees showed modest increases in species richness on fields with management agreements. Our results indicate that there is a pr essing need for a scientifically sound evaluation of agri-environment schem es.