Untersuchungen zur Entwicklung der Waldvegetation des Hakels (nordöstliches Harzvorland)

Abstract

The forest vegetation of the Hakel is characterized by the existence of different types of broad-leaved deciduous forest communities which are described. Oak-hornbeam-forests are dominating on the plain loess-covered sites accompanied by dry oak-forests on shallow slopes and sycamore-ash-forests on slope-foot sites on the bottom of small valleys. Comparing the actual vegetation with results of former investigations and historical datas it could be ascertained, that the existing vegetation structures result of different earlier impact of forest management favouring oakhornbeam- forests proceeding from the Middle Ages until to this century. Actually, a decline of light prefering thermophilous herbaceous species as well as an increase of species characterizing an enhanced eutrophication and ruderalization at the forest borders can be observed. Earlier forest management practices are reflected by the dominance of oaks formerly prefered for mast of domestic animals and by the frequency of wild fruit trees. The impacts of modern forest management are influencing the microclimatic conditions within the stands to higher humidity and so favouring a development towards to morenatural forest succession. Actual tendencies of changes are expressed by the increase of beech, ash and sycamore and a retreat of both oak species. Especially for the beech a higher importance within the canopy structure is expected in future. Conclusions are made concerning future measures of nature conservation and forest management. The importance of protecting natural development processes and the conservation of some rare dry forest species, witnessing the influence of former forest management practices is emphasized.