VEGETATION AND HYDROLOGY IN A SPRING MIRE COMPLEX IN WESTERN POMERANIA, POLAND

The vegetation of one of the largest spring mires in Poland has been s tudied with special regard to hydrological conditions and stratigraphi c development of the mire. Despite its biotic richness the mire is in a slow state of deterioration, initiated by man several hundred years ago. Evidence has been found that drainage occurred in an originally t reeless percolating mire (sloping fen), possibly as a result of hydrol ogical changes in a lower lying lake. The development of the springs w as probably a reaction to the increased resistance to water flow in th e percolating mire, forcing the groundwater to discharge high up at th e sand borders. The eroding effect of the spring water courses increas ed the drainage and, although the springs also provided new habitats f or rare moss communities, a considerable eutrophication in the present spring alder wood can be noticed.