Restoration of flooded meadows in Estonia - vegetation changes and management indicators

Question: How does restoration management affect vegetation diversity and composition in flooded meadows, and can plant species serve as indicators of management status? Location: Flooded meadows in Alam-Pedja Nature Reserve, central Estonia (26 degrees 14' E, 58 degrees 28' N). Methods: Plant community composition was described in 2000 and 2010 for restored and unmanaged stands of mesic, wet and tall sedge meadows, encompassing a survey of 280 vegetation plots of 1 m 9 1 m. The impact of restoration management (mulching for first 5 yrs, mowing in Jul with hay removal in consecutive years) on vegetation diversity in different meadow types was estimated using general linear models, changes in plant community composition were described by NMDS ordination, multiple permutation tests and Indicator species analysis. Results: Restoration management resulted in an increase in species richness on mesic meadows in one of the study sites, and caused a decrease in spatial species turnover and significant changes in community composition in all sites. The effects of restoration on species composition were greater in drier, more elevated mesic meadows, and least prominent in tall sedge meadows in floodplain depressions. Indicator species analysis revealed Ranunculus auricomus as a common indicator of management in mesic and wet meadows, and Carex cespitosa and Calamagrostis canescens as indicators of abandonment in wet and tall sedge meadows, respectively. Conclusions: Restoration management was successful on flooded meadows that had been abandoned for 15-20 yrs, where water regime and soil fertility have not been altered by human activities, and where the local species pool is still available. The current community composition under different management regimes made it possible to propose several species as management status indicators, which may further be used in practical decision-making when evaluating the status of meadow communities.