Grassland Ecosystems in the Varied Hydrological and Ecological Conditions of the Kulawa River Valley

摘要

Grasslands in the Kulawa river valley (ca. 10 ha) were subject to land improvement in the 19th century, and remnants of the hydrotechnical system and overgrown ditches are still present. This study aims to:rn(1) evaluate the present meadow ecosystems;rn(2) predict their changes under the influence of the planned restoration of the hydrotechnical system andrn(3) compare results of various methods: phytoindication, phytosociological, floristic, and principal component analysis.rnThe applied methods complemented one another. The devastation of the hydrotechnical system and the lack of utilization of the grasslands have led to either drying or waterlogging of the soil, and to changes in vegetation. The plant communities that have developed there represent the intermediate stage of regressive succession, and belong to the orders Arrhenatheretalia, Molinietalia, and the class Phragmitetea. Particularly the patches growing on relatively dry, strongly decomposed peaty soil have lost the characteristics of damp meadows. Meadow species have declined there, and nitrophilous species have replaced them. Only a local depression without outflow, which was earlier drained, is now waterlogged again, with a mosaic of calcareous fen, meadow, and marsh vegetation, including large populations of 11 species that are rare, protected, or listed as indicator species for the Natura 2000 habitat 7210~*. Results of this study indicate that the present conditions in the waterlogged depression should be preserved. In contrast, the dry patches should be irrigated and subject to extensive farming.