Impact of site and management on the diversity of central European mesic grassland

The main objective was to quantify the relative impact of current management types on plant species-richness and composition of mesic grasslands with regard to other important determinants such as topography, soil chemical parameters and grassland age. The grasslands were (i) differentiated into management types and vegetation types, (ii) these types were tested for differences in site conditions and species-richness, and (iii) the relative impact of management, site conditions, grassland age and regional scale geomorphology on floristic composition was quantified. TWINSPAN classification of the vegetation separated nutrient-poor from nutrient-rich sites. Results of ANCOVA revealed that vegetation types indicating high nutrient levels showed significantly higher contents of plant available phosphorous and younger grassland age. In partial CCA analyses, the geomorphology accounted for almost one third of explained variance. The current management had a relatively low explanatory value. Soil chemical variables and topography, in contrast, explained together almost twice as much variation in floristic composition.