Effects of short-term grazing exclusion on vegetation and soil in early succession of a Subhumid Mediterranean reclaimed coal mine

Aims To assess the short-term effect of herbivory exclusion on vegetation and soil and to relate differences in floristic composition to changes in soil properties in a reclaimed coal mine in northern Spain. Methods Two adjacent main plots of 50×50 m, one fenced to prevent ungulates grazing and the other not, were established in a north-facing slope to analyze differences in the soil and plant community in the short time. Results A clear influence of grazing exclusion on soil properties and plant community composition and structure was found but no influence on species diversity. However, only three soil parameters (organic matter, K, and Mg, with higher values in the ungrazed community) were related to the differences in floristic composition. Species responses to the soil gradient from ungrazed to grazed areas were also related to their particular lifehistory traits. No trend in the dispersal-mode replacement was found. Conclussion Herbivores could be a key factor preventing revegetation at early stages of succession in the study area, although they could play a key role as efficient seed dispersers, particularly of endozoochorous legume species, and controlling the expansion of dominant introduced species.