Comparative phytosociological investigations of windbreaks and other hedgerows of the Querfurter Platte (central German dry region).

This publication presents the results of phytosociological investigations on windbreak-hedgerows and other hedgerows in the old arable landscape "Querfurter Platte" which is today poor in trees, shrubs and similar structures. This landscape is part of the "Mitteldeutsches Trockengebiet" which is situated in the rain-shadow of the Harz mountains (precipitation less than 500 mm/year). In the fifties and in the eighties windbreak-hedgerows were planted in the fields to reduce the eroding force of the wind on the soil. These windbreaks and other hedgerows (on embankments, narrow passes and on xerothermic places at the western edge of the "Querfurter Platte") were investigated and compared. Especially in the herbaceous layer clear differences were found between several types of hedges. The herbaceous layer of windbreakerhedges is characterized by nitrophytic ruderal and segetal plants. Juvenile specimens of Carpino-Fagetea - trees or shrubs widespread in the region were noticed very scarcely, even after 30 years in these hedges - apart from elder (Sambucus nigra), a nitrophytic shrub-species. It is recommended to reserve a strip of 5 m width on both sides of the hedges in order to enhance the growth of grasses and other perennial species in the local ecosystem.