Long-Term Effects of Scrub Clearance and Litter Removal on the Re-Establishment of Dry Alvar Grassland Species

Abstract

Many characteristic dry alvar grassland species disappear after cessation of livestock grazing as a result of encroachment by Juniperus communis. We studied the re-establishment of these species after scrub clearance with and without the removal of the layer of litter and mosses in long-term (14 years) permanent plots. Most of the species belonging to the community species pool of dry alvar grassland species before clearance were found in permanent plots between 2 and 14 years after the clearance. A large part originated from vegetative spread of already occurring species in the established vegetation in the surroundings. Only a small part of the long-term persistent soil seed bank resulted in the re-establishment of alvar species. There was no significant difference in the traits soil seed bank, seed weight and long-distance dispersal by wind, dung or fur of animals of established and non-established species. Removal of litter and mosses positively affected the re-establishment of alvar species.