Einfluß der Landschaftsstruktur auf die Verbreitung von Pflanzenarten im Mitteldeutschen Trockengebiet

Abstract

WANIA, A.; KÜHN, I.; FRÜHAUF, M.; KLOTZ, S.: Influence of landscape structure on the distribution of plant species in Central Germany.- Hercynia N.F. 35 (2002): 215-231.As discussed in recent publications, the distribution and diversity of plant species is no longer only influenced by natural conditions, but also very strongly by human activity. Two processes are the main causes: the natural landscape structure has been transformed by cultivation, urbanisation and the construction of roads and railways, and many bio-geographical barrier ranges of species were eliminated by the deliberate and unintentional transplantation of species. Extremely high species numbers in certain ecosystems contrast the loss of biodiversity on the global scale. This requires the investigation of the factors involved in the distribution and diversity of species in today’s cultivated landscapes. This study especially focuses on the relationship between plant biodiversity and landscape structure. The study sites are located within a characteristic landscape in Central Germany (Saxony-Anhalt), which is defined by urban centres and large agricultural fields. The study is based on two different study areas and compares mainly urban sites (within the city of Halle) with those dominated by agriculture (surroundings of the ‘Süßer See’ situated to the West of Halle). Both sites differ considerably in land use pattern. The landscape structure was analysed using landscape metrics after MCGARIGAL et MARKS (1994). The number of landscape metrics is reduced by performing principal component analysis. Principal components and species numbers are then placed in a multiple linear regression. The results show that the number of species found in the urban landscape is higher than that of the agricultural landscape. This is the case for native as well as alien plant species. The most decisive factor for biodiversity in general and the high diversity of native plant species on the local scale is the variety of landscape structures that is mainly caused by anthropogenic land use. The alien plant species show a stronger dependence on the proportion of anthropogenic land use.