Long-term changes in calcareous grassland vegetation in North-western Germany – No decline in species richness, but a shift in species composition

摘要: Abstract We aimed to answer the question of whether species richness and composition calcareous grasslands in North-western Germany had changed over last 70 years as a result atmospheric nitrogen (N) deposition. In total, 1186 plots Festuco-Brometea (alliance Bromion erecti ) from sub-oceanic regions country were compiled (1061 literature sources spanning time period 1936 1996, 125 new 2008). Environmental descriptors recorded for each plot included geographic coordinates, altitude, heat index (combining slope aspect), mean Ellenberg indicator values light, soil moisture, pH N, cumulative N deposition (the latter being highly positively correlated with year sampling). Detrended Correspondence Analysis, sample scores along axis one N-values, those two significantly affected by sampling. general linear model, vascular plants showed markedly hump-shaped relationship N-value, whereas it was weakly (cumulative load). Species significant negative trend more often (than expected chance) habitat specialists dry grasslands, small, light-demanding winter-green or evergreen smaller seeds scleromorphic leaves. contrast what has been found acidic did not decline richness, most likely because are water- phosphorus-limited, well-buffered terms pH. To prevent further change towards mesophytic communities, grassland management site managers needs be intensified.