Untersuchungen über Vegetationsveränderungen durch Stickstoffeintrag in österreichische Waldökosysteme

Abstract

160 vegetation releves in forests and bogs, which were first observed between 1958 and 1965, were repeated in 1989/90, and the indicator values of ELLENBERG (1979) were compared. Most of the forest communities treated in this study are species-rich and grow on calcareous soils. No general increase of N-values could be found, however, some nitrogen indicating species are now more frequent than before. An increase of N-values was more often found on relatively humid sites, e.g. on shady slopes. It was often linked with a slight increase in moisture values and sometimes a decrease of R-values. The effect of a welldefined nitrogen input was checked on 10 experimental plots fertilized between 1963 and 1967. In all cases a combination of fertilizers had been used. Only in some cases higher N-values could be found