Vegetationsdynamik und Florenwandel im ehemaligen mitteldeutschen Waldschutzgebiet "Hainich" im Intervall 1963 - 1995

Abstract

Changes in vegetation and flora of beech forests in the lower mountainous limestone region of Central Germany during the past 3 decades have been investigated and are discussed. In 1963 a phytosociological inventory had been carried out on 51 test plots. 11 out of 12 vegetation units found in 1963 were still present in 1995, but only 27 in 51 test plots remained in the same state refered to the concerning vegetation units. Causal factors of these changes which have to be considered are first the increase of stand canopy closure, enhanced by nearly missing sylvicultural measures between 1965 and 1992; so shade-tolerant species of the field-layer vegetation like Allium ursinum and Veronica montana (newcomer) were able to expand considerably. Second the permanent impact of air pollution, especially nitrogen compounds, is promoting herbaceous species with higher demand on moisture and nitrogen supply of the sites, among them first of all Circaea lutetiana. The acidification of soils seems to have up till now no remarkable influence on composition and development of plant species. The described area is proposed to become nature preserve again- within the beech wood national park "Hainich".