Plant communities and environmental gradients in mires of the Ammergauer Alps (Bavaria, Germany)

In this study we present the plant communities, their abiotic site conditions and the main environmental gradients underlying variation in species composition of mire sites in three montane mires in the Northern Limestone Alps. For the phytosociological description of the mires we sampled species composition in 115 releves. In order to characterize the site conditions of the most important plant communities we measured humification as well as water table depth, pH and electrical conductivity at 46 sites during a large part of the growing season. The main environmental gradients were identified by fitting environmental vectors and smoothed surfaces onto NMDS ordination. The most frequent communities on subneutral and neutral sites were the Caricetum davallianae, the Amblystegio stellati-Caricetum dioicae and the Schoenetum ferruginei, whereas acidic sites were mainly covered by the Eriophoro-Trichophoretum cespitosi. The most important factor for floristic variation between sites was pH. However, within bogs and fens, variation in species composition was mainly due to differences in water table depth.