Changes in the arable flora in recent decades and their possible impacts on farmland birds

The article provides insights into the effect of agricultural intensification processes on shifts in arable vegetation composition, and discusses potential consequences for associated bird communities. The analysis bases on observational studies carried out in Central Germany. Our analysis revealed a 25 % reduction in the number of plant species in the regional species pool over the last 50 years, dramatic frequency losses of many species and decreasing population sizes of rare and diagnostic species. The results also indicate that the magnitude of vegetation changes depended on the geological substrate. Furthermore, the average cover of arable plants has decreased to a tenth of its original value, while crop cover generally increased and crop diversity decreased. The observed homogenization in community structure with both specialists and diagnostic species disappearing and also generalists decreasing reflects the growing uniformity in crop management, and the increase in soil fertility levels in recent years. Arable plant species that are of considerable importance as food plants for seed-eating farmland birds have shown strong population declines. Partly as a result of this, no other bird species group in Germany has been affected by such a strong and ongoing population decline as farmland birds in recent decades. Meeting the declared target of achieving a significant increase in biodiversity in agricultural ecosystems by 2020 will require the rapid development of new, effective and innovative conservation schemes and programs.