Vegetation, soils and seed banks of limestone grasslands are still impacted by former cultivation one century after abandonment

This study identifies the long lasting impacts of former cultivation on soils, seed banks and above-ground vegetation of limestone grasslands. We compared the resilience of three crop fields cultivated in the 19th century and abandoned (Abandoned Fields) with three grasslands which have never been cultivated (Old Grasslands). Grasslands were located in the Nature reserve of Grand-Pierre and Vitain valleys in France. Sites were identified using historical sources. Chemical and physical soil properties, above-ground vegetation and soil seed bank (0-10 cm and 10-20 cm) were studied. Data were analysed using a multivariate and univariate analyses to detect the effects/impacts of ancient cultivation. Our results clearly show that soil properties (e.g., calcium, carbonate, clay contents), above-ground vegetation (species diversity, moss and lichen cover) and seed bank (floristic composition, species-richness and diversity) are still impacted more than one century after their abandonment. Species richness of both above ground vegetation and seed bank are higher in old grasslands than in formerly cultivated fields. In the seed bank of the formerly cultivated soils we also found the presence of a very rare arable weed species (Althaea hirsuta)which has not been inventoried for a long time in the above-ground vegetation of the nature reserve. The resilience of formerly cultivated limestone grasslands might be influenced by the present management regime (site effect). Nevertheless, the resilience period of limestone grasslands is very long-more than one century-and return to an initial state might be difficult or impossible to reach.