摘要 : Importance of different habitat types for aims of preservation of endangered vascular plants in the Elbe-Weser-region (NW-Germany). – The value of different vegetation types for the purpose of nature conservation was assessed in o... 展开 Importance of different habitat types for aims of preservation of endangered vascular plants in the Elbe-Weser-region (NW-Germany). – The value of different vegetation types for the purpose of nature conservation was assessed in order to identify priorities of protection measures for highly threatened species of vascular plants in the Elbe-Weser-region (northern part of Lower Saxony, Bremen). The habitat preferences of 144 selected endangered species, which are considered to be of particular importance for regional plant species conservation, were analysed based on the information given by ELLENBERG & al. (1991). The ranking of vegetation types according to the number of inhabiting species of particular interest for nature conservation shows the importance of traditionally used, "historical" landscape elements. The most important phytosociological units are as follows (numbers of species of "special interest" and of threatened species included in the red data books of Germany resp. Lower Saxony and Bremen are given in brackets): Molinietalia (19/G 18/LS 27), Scheuchzerio-Caricetea nigrae (13/G 22/LS 23), Littorelletea (12/G 15/LS 15), Phragmitetea(11/G 17/LS 18), Nardo-Callunetea (11/G 13/LS 19), Querco-Fagetea (11/G 8/LS 17), Isoeto-Nanojuncetea (10/G 9/LS 13), and Potamogetonetea (6/G 12/LS 16). Essential for the maintenance of high plant species diversity, specially with respect to highly endangered,light-demanding species of nutrient-poor soils, are: Avoidance of any further nutrient input, occasionally also nutrient withdrawal, and the preservation of open habitats by grazing and cutting or other management measures,e.g. sod cutting or dredging. 收起