Effect of experimental top soil removal on vegetation of Pannonian salt steppes

Inland saline habitats of the Pannonian Lowland exhibit a specific variety of grasslands determined by a soil salinity gradient. Changes in the hydrological regime and absence of management have resulted in heavy degradation of the vegetation. The impact of topsoil removal on salt steppes was tested by a 3-year small-scale manipulated experiment in SW Slovakia (Kamenínske Slanisko Nature Reserve). Topsoil was removed in three contrasting types of vegetation with different soil salinities, i.e. in different stages of habitat degradation. Data were analysed by multi-way ANOVA and by multivariate methods. Species richness decreased and the proportion of halophytes increased significantly in the two types with the highest soil salinity; however, the total number of halophytes was not influenced by soil removal. The treatment caused inhibition of secondary succession on the plots with the highest salinity. The effect of the soil removal was only short-term in the vegetation with moderate salinity and on heavily degraded and desalinized types it even stimulated further recruitment of ruderal species. Topsoil removal has only limited potential for the restoration of Pannonian salt steppes. It should be applied only in slightly degraded vegetation, where salt accumulation is still present and target species propagules are available.