Short-term effects of recent land-use changes in Eastern Austria on farmland bird assemblages in a human-dominated landscape

摘要

To study effects of short-term land-use changes on birds in a predominantly agriculturally used landscape in Northeastern Austria, birds were surveyed in 22 circular study areas with a diameter of 1 km in 2005 and 2009. Because of the abolition to obligate set-aside land from 2008, it was suspected that the amount of set-aside land would be reduced dramatically. Consequently, a loss of farmland birds was expected. Results show that the amount of set-aside land indeed decreased significantly between 2005 and 2009 from 15.05% to 9.69% (mean proportion of set-aside land per study area). Farmland birds were represented by 20 species in both years. Neither richness and abundance nor species composition of farmland birds were affected by changes of set-aside land. The amount of set-aside land in these landscapes was already high (compared to other areas in Austria) before the amendment of the law and still relatively high after it. Therefore, perhaps changes in the extent of set-aside land were below the threshold to find detectable effects on farmland birds.