Skalendifferenzierte Auswirkungen großflächiger Beweidung auf die Artenvielfalt des Südschwarzwaldes

Due to the increasing rate of fallow land Central Europe? s rural landscapes are in need of alternative land use concept s, combining the aims of Conservation and agriculture. According to the approach of ?semi-open pasture landscapes? the implementation of large scaled low-intensity-pasture-systems are actually discussed and partially tested only in small areas. As target state the traditional, collaborative land use systems of the Southern Black Forest with it? s widely well preserved `Állmende? pastures are often mentioned. It is necessary to check the model character of the Southern Black Forest `Allmende?-pasture-systems and their future roll as target state of alternative land use and conservation strategies . Therefore the `Állmende? (young cattle) pastures are compared with other local land use forms of the grassland dominated region. The `Állmende? (young cattle) pastures feature a more diverse vegetation structure than meadows with different mowing regimes and than dairy cattle pastures. Also their contribution to regional biodiversity is much higher, analysed with indicator groups as locusts (orthoptera) and butterflies (lepidoptera). The high biodiversity of the `Állmende? pastures is mainly caused by low stocking rates (cp. Stocking capacity is constant ~0,5-0,6GVE/ha), area size and aspects of historic land use. The latter effect is composed of different `beside-utilisations?, which were services in the regulating system of the `Allmende? like clearing, cutting or fertilising. But these `beside-utilisations? have changed in the past two centuries as much as the land use system itself, what could be demonstrated for three boundaries in the Southern Black Forest using GIS. Because of the region-typical history of development a transfer to general guidelines is restricted. Anyhow `Állmende? pastures are optimally qualified as target states of nature conservation Still there is a lack of knowledge of the functionality of large scaled pasture systems and their effects on diversity and distribution of organisms. A second main focus analyses the utilisation patterns of cattle and their consequences for vegetation structure and distribution of indicator species groups, refereeing to a functional chain: pasture management ®pasturing®vegetation structure®species distribution. Therefore `Állmende? pastures were analysed on meso-scale. utilisation patterns of cattle was detected with serial-photos from the opposite mountainside. Characteristic cattle behaviour were found in certain areas why the pastures could be divided in functional objects. Vegetation, spatial neighbourhood effects and pasture management were reasons for this heterogeneous utilisation patterns, what could be proofed in geostatistic regression models (glm). The utilisation patterns generate characteristic patterns of vegetation structure, which is mainly affected by site as a second level of regression models show. Third level of analysis are the effect of pasturing on the distribution of locusts and butterflies. Their occurrences are affected by vegetation structure (e.g. high density of blossoms), site and spatial neighbourhood effects, shown by the third level of regression models. Special effects and functionality of `Állmende? pastures were analysed on micro-scale. Therefore different `Micro-structures? under varying land use influence were studied. The Variety of `Micro-structures? are responsible for high species diversity of `Állmende? pastures. Besides they are keystone habitats in the life cycle of species e.g. the reproduction and oviposition of locusts.