The influence of habitat heterogeneity on bird diversity in Irish farmland

The intensification and specialisation of agricultural practices have led to a widespread decline of farmland bird diversity across much of Europe. Increasing habitat heterogeneity at Multiple Spatial scales has been suggested as one possible strategy to reverse these declines. This study examined the relationship between habitat heterogeneity, as ineasured by a nurnbcr ofindices, and bird diversity at farm scale using study sites in the east and south-east of Ireland. Generalised Linear Models indicated that there was a positive relationship between the documented heterogeneity of farmland habitats and the numbers of bird species observed during standardised farm surveys. However, this relationship was not evident when bird diversity was quantified using both the Shannon and the Simpson's diversity indices. It is concluded that agri-environmental policy that aims to influence the heterogeneity of habitats at the farm level can provide a useful means to maintain farmland biodiversity. Future research should aim to develop in improved system of habitat classification and a deeper understanding of the ecological value of different habitat types in Irish farmland.