Impacts of Restoration and Management Measures on the Spezcies Composition and Diversity of Vascular Plants and Cryptogams in Newly Established Calcareous Low-nutrient Meadows

27 Mar Impacts of Restoration and Management Measures on the Spezcies Composition and Diversity of Vascular Plants and Cryptogams in Newly Established Calcareous Low-nutrient Meadows

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Abstract

English Abstract

In 1993, calcareous grasslands were created on former arable fields with and without topsoil removal by transfer of diaspore-containing hay from the adjacent Garchinger Heide nature reserve. The species diversity of vascular plants, bryophytes and lichens was analyzed on the restoration sites between 203 and 2005 and compared to sites in the nature reserve. After twelve years of management, both overall species richness and bryophytes and lichen species richness of the topsoil removal sites exceeded those of the sites without topsoil removal. In contrast, the species richness of vascular plants was higher on sites without topsoil removal. Species richness of bryophyte and lichen species was higher on newly created topsoil removal sites than on a 60 year old topsoil removal site within the nature reserve and the number of vascular plant species was lower. The newly created sites without topsoil removal showed a higher species richness of vascular plants and all plant species, but lower bryophyte species richness than the reference sites in the nature reserve. The number of vascular plant target species of the class Festuco-Bronetea was higher at the sites in the nature reserve than on the corresponding former arable fields with or without topsoil removal. Similar results were found for the target species of bryophytes and lichens, which were defined as species of the Abietinellion, Tortelletum inclinatae and Tominion cearuleonigricantis. On restoration fields without soil removal, the number of vascular plants, bryophytes and Festuco-Brometea species was lower on sites mowed twice a year than on sited mowed once a year or grazed. Sites mowed once a year and grazed sites hardly differed in species number, but thesite mowed once a year showed the highest dry mass of pleurocarpous mosses, indicating unsuitable, conditions for slow-growing cryptogam species. Our results show that topsoil removal in combination with hay transfer is a suitable method for the restoration of calcareous grasslands. On sites without soil removal, mowing once a year or grazing is more beneficial ro target species establishment than mowing twise a year. The target species groups defined in our work, i.e. Festuco-Brometea species, bryophyte species of the Abietinellion and Tortelletum indinatae and lichen species are suitable indicators for the evaluation of retoration success.