Restoration of species-rich dry heaths: the importance of appropriate soil conditions

The aim of many rehabilitation projects in degraded ecosystems is to restore biodiversity. In order to achieve this, restoration often focuses on abiotic conditions as they are the main cause for the degradation of the ecosystem. The necessity of restoring the soil conditions for rehabilitation of heathland vegetation is shown by this study. Three dry heathland areas were studied; an acidic species-poor heath which is degrading as a result of atmospheric nitrogen deposition, an acidified matgrass sward and an abandoned grassland. We aimed to restore the characteristic plant communities of the heathlands: a Calluno-Genistion pilosae community in the acidic speciespoor heath and a Nardo-Galion saxatilis community in both the acidified matgrass sward and the abandoned grassland. Restoration methods included sod-cutting to the mineral soil layer, liming and a combination of sod cutting and liming. Effects of these methods on top soil chemistry, vegetation development and development and demography of the rare Arnica montana are shown and discussed. Furthermore, we discuss the importance of seed availability in relation to the importance of restoring soil conditions for successful rehabilitation of heathlands.