Biomass accumulation during reed encroachment reduces efficiency of restoration of Baltic coastal grasslands

Abstract

AbstractQuestionTo what extent is restoration of vegetation in coastal grasslands delayed by accumulation of nutrients after abandonment of traditional management and subsequent reed encroachment? How does nutrient flow in the plant–soil system react to reintroduction of grazing?LocationCoast of Baltic Sea, western Estonia.MethodsAbandoned, continuously managed and restored coastal meadows were selected in four different study regions and their vegetation composition sampled. Nitrogen, P, K, Na, Ca and Mg concentrations and C/N ratios were determined in both vegetation and soil. Differences between management groups were evaluated.ResultsComparison among different management groups revealed several differences in both relative and total amount of nutrients in soil and vegetation. Most soil properties of restored sites were similar to those in abandoned sites. Carbon stock in the soil profile doubled after abandonment, total N concentration in the top soil layer increased while plant available P concentration decreased. The phytomass and chemical composition of phytomass rapidly changed back to a ‘normal’ level after restoration. Species composition remained different, but species typical of coastal grasslands were present in restored sites. There was a strong site specificity in the results.ConclusionsRe‐establishment of grazing had a rapid impact on plant biomass of coastal grasslands. Species composition responded more slowly, but target species returned relatively quickly. Slow recovery of soil properties, however, means that the results of restoration may be fragile and return of tall‐growth vegetation is very probable if managent intensity declines. Long restoration periods should be planned to reach pre‐abandonment environmental conditions when using non‐destructive restoration methods.