Julius-Kühn-Archiv (Jan 2013)
Bewertung und Verbesserung der Biodiversität in landwirtschaftlichen Gebieten unter besonderer Berücksichtigung von Vogelarten als Bioindikatoren
Abstract
Agricultural landscapes have crucial functions for biodiversity conservation. Contrary to the goals of biodiversity protection the habitat functions and the biological diversity are deteriorating, especially in arable areas. In this respect, the occurrence and abundance of bird species are important indicators for biological diversity and landscape quality. In order to gain precise information about the preferred habitats for indicator bird species in arable areas, we conducted field studies according to the territory mapping method combined with data of the agricultural land use. We studied 29 agricultural areas, each with a size of 1 km x 1 km in 2009 and 2010. In a hierarchical design we analyzed habitat characteristics on different spatial scales: agricultural landscape, sections of agricultural landscape, habitats, including crops, vegetation structure, and habitat matrix. The species diversity and the abundances were calculated for the various spatial scales in relation to the agricultural crops. For example, the abundances of the skylark pointed to a preference for a more open, light vegetation structure (height, coverage, density) of the crops. With help of vegetation matrix analysis the habitat configurations of the territories for skylark, corn bunting, yellowhammer, yellow wagtail, whinchat and redbacked shrike were analyzed. In comparison of this configurations to the habitat structures in the agricultural landscape, significant deficits of suitable habitats for farmland bird are evident. Especially, a need for natural and semi-natural grassland vegetation, e.g. self greened fallow fields and bird species specific minimum occurrence of semi-natural habitat structures like hedges or small water bodys become clear. A high diversity of crops contributes to high diversity of vegetational diversity and thus to bird species diversity. The identification of suitable habitat configurations for farmland bird species can be translated into meaningful approaches for the conservation of biodiversity, e.g. through agri-environmental schemes.
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