Zum Einfluß von Standort und Nutzungsgeschichte auf die Grünlandvegetation in der Saale-Aue bei Holleben (Saalkreis)

Abstract

We studied the vegetation of the Saale river flood plains near Holleben (district of Saalkreis, SachsenAnhalt,Germany) in 1995 and 1996. The area consists in one part of small orchards, in the other oflarge-scale meadows and pastures. In both cases the traditional way of land use was a twice a yearcutting regime. Parts of the large-scale grassland were grazed more or less intensely for many decades.While industrial methods of land use were introduced since the 1970s in the large-scale grasslandareas, the traditional way of use was maintained in the orchards. Some parts of the study site becamefallow land during the last 30 years, other parts were used as arable land during several years. Thepolitical change of 1989 caused a decline in the intensity of land use, especially for the meadows, butnot in the same way for the large-scale pastures. In general the application of organic manure andmineral fertilizer decreased significantly or was stopped at all.28 vegetation units belonging to Phragmitetea australis, Agrostietea stoloniferae, Artemisietea vulgaris,Galio-Urticetea dioicae, Polygono-Poetea annuae and Molinio-Arrhenatheretea could be distinguished.Their distribution was mapped (fig. 3). Leveled transects proved the influence of small scaledifferences in altitude (the overall elevation amplitude is 2m) and ground water Ievel on the vegetationcomposition. The comparison of corresponding grassland communities from the orchards and the largescalegrassland gave evidence of the latter containing generally more ruderal species and the overallspecies number being lower there than in the orchards. These differences are mainly due to the contrastingmanagement regimes in the last decades. In the large-scale grassland high nutrient input andthe combination of several cuts per year with grazing favoured the establishment of ruderals and ofhighly competitive species, while other species vanished. These tendencies are the same as in otherriverine grassland areas of Central Germany. Nevertheless many endangered species of the Red DataBook of Sachsen-Anhalt (in the whole study area there are 24) and also vegetation units such asSanguisorbo-Silaetum silai and Scutellario-Veronicetum longifoliae, being nowadays rare, are stillfound in the large-scale grassland. They survived in those plots, which haven't been grazed or turnedinto arable land. Additionally the orchards with their special site conditions maintain several species ofspring geophytes.Finally advices for a future management according to nature conservation aims are given.