Grassland restoration to conserve landscape‐level biodiversity: a synthesis of early results from a large‐scale project

Abstract

Abstract Question European landscapes have long been influenced by intensifying use by humans. Although habitat restoration can reverse this process, it is often limited in scope by socioeconomic constraints. Here we present a grassland restoration project that is exceptional in spatial scale in E urope. Location A total area of 760 ha of arable land was restored in the E gyek‐ P usztakócs unit (50 km 2 ) of H ortobágy N ational P ark, east H ungary, between 2005 and 2008. Methods Restoration targeted alkali steppes and loess grasslands by sowing seeds of either two (alkali) or three (loess) foundation grass species. In 2009, we surveyed the vegetation in restored and target grasslands and quantified the factors influencing restoration success in a space‐for‐time substitution design. Results We recorded 100 species of flowering plants, of which 37 species were non‐weed, ‘target’ species. Annual weeds dominated 1‐yr‐old fields but had decreased dramatically by the third year due to a developing perennial grass cover. Former alfalfa fields had proportionally fewer weeds than former cereal and sunflower fields. The diversity of common species and the cover of target species increased from 1‐ to 4‐yr‐old restored fields. Alkali‐restored fields had more heterogeneous vegetation and more species than loess‐restored fields. Distance to the target vegetation did not directly affect vegetation variables. There was significant spatial variability in vegetation development, possibly suggesting several local pathways of succession. Conclusions Grassland restoration was generally successful in accelerating secondary succession towards alkali steppes and loess grasslands. However, further management is necessary to counter the homogenizing effects of litter accumulation, to reduce perennial weeds and to enhance the colonization of target species. Our project provides useful practical insights into grassland restoration and in applying restoration at a number of sites within a larger area to conserve biodiversity at the landscape scale.