Spontaneous succession of vegetation on acidic bedrock in quarries in the Czech Republic.

Variability in vegetation, participation of target and non-target species and the role of the local species pool in the spontaneous succession on acidic bedrock were studied in quarries. The study was conducted in the Českomoravská vrchovina uplands (central Czech Republic). A total of 135 relevés, 5 × 5 m in size, were used to sample 41 quarries that were abandoned from 1 to 92 years ago. Three types of sites were distinguished: mesic, wet and periodically flooded. Species cover (seven point Braun-Blanquet scale) was visually estimated. The following characteristics were noted: steep rocky slopes, bottoms and levels, dumps and screes as habitat types; age; proportion of the main land-cover categories (arable land, ruderal and urban, grassland, woodland and wetland) in the surroundings up to 100 m and 1 km from each quarry; and the occurrence of target (grassland, woodland, wetland) and non-target (ruderal, alien) species up to 100 m from each quarry. Ordination indicates that the spontaneous succession of vegetation results in the formation of mixed woodland, Alnus and Salix carrs, or tall sedge and Typha beds with scattered Salix, depending on the wetness of a site, surrounding vegetation and land cover. Restoration of target vegetation in the quarries by spontaneous succession is possible and can occur within about 25 years, especially if the target species are present close by.