In protected areas the maintenance of existing phytodiversity is an important conservation target. In this study, we analysed over a period of 9 years the effects of abandonment on plant species composition and species richness in a montane grassland in the Long-term Ecosystem Research (LTER) region Eisenwurzen (Styria, Austria). Additionally, investigations were made concerning number of Red Data List species, plant strategy types, Ellenberg indicator values, indicator values for mowing, grazing and trampling tolerance, temporal sequence of phenological phases and seven plant traits. We differentiated two topography-related habitat types: an initially species-rich sheep pasture on a steep, south-facing slope and a less species-rich meadow on a flat site immediately below with a comparatively higher nutrient and water supply in the topsoil. Testing a possible management alternative, on the slope also the effects of continued low-intensity sheep grazing were analysed. In spring 2001, one permanent plot of 50 m² in the centre of each habitat type and treatment was established. Our results show that the long-term effects of abandonment on grassland vegetation depend largely on local site conditions. Especially, nutrient availability in the soil seems to be an important factor. On the abandoned flat site, within 4 years floristic composition and physiognomy changed dramatically, a high species turnover and a decline in phytodiversity could be observed. In contrast, on the abandoned slope site we found only minor effects, even after 9 years of abandonment. If the maintenance of existing phytodiversity is a conservation target, suitable management operations have to be carried out at shorter intervals (approximately every 3 years) in habitats with nutrient-rich soils compared to nutrient-poor habitats (at least every 5 to 10 years). From a nature conservation point of view, low-intensity sheep grazing may be a suitable management alternative to mowing.
Bohner, A., Starlinger, F., Koutecky, P. (2012): Vegetation changes in an abandoned montane grassland compared to changes in a habitat with low-intensity sheep grazing - a case study in Styria. Eco.mont 4, 5-12