摘要 : Intensification and abandonment of European farmland and consequent changes, usually declines, in farmland bird populations are strongly linked to the European Union's (EU) Common Agricultural Policy. The 12 Central and Eastern Eu... 展开 Intensification and abandonment of European farmland and consequent changes, usually declines, in farmland bird populations are strongly linked to the European Union's (EU) Common Agricultural Policy. The 12 Central and Eastern European countries which joined the EU in 2004 and 2007 support higher densities of farmland birds overall than the first 15 member states, and are therefore disproportionately important for farmland bird conservation in Europe, but are vulnerable to changes in farmland avifauna as a result of accession to the EU. Changes in farmland bird abundance and species richness on 71 1-m squares in Poland from shortly before (2002) to five years after (2009) EU accession were examined in relation to changes in agricultural management. There was a decline in the cover of low-intensity farmland between these years, partly as a result of previously abandoned or fallow land returning to production, but there was also a loss of farmland to woodland or scrubby woodland, indicative of agricultural abandonment. The loss of low-intensity farmland was associated with decreases in the abundance of nine of 28 bird species examined, five of them already declining in the EU as a whole, although these effects were sometimes region-specific. he increase in woodland edge habitat had species-specific effects. There were detectable changes in agricultural management and associated bird populations in Poland five years after EU accession. If such trends continue, they are likely to lead to substantial long-term changes in Poland's internationally important populations of farmland bird species 收起