A decade of vegetation development on two revegetated milled peatlands with different trophic status

Milled peatlands in the Northern Hemisphere are frequently restored in order to mitigate negative effects of climate change and to benefit biodiversity. The aims of this study are to analyse the development of vegetation on milled peatlands in Estonia after restoration using the moss layer transfer technique (MLTT), relate the plant functional type cover with peat chemical factors, and study correlations between bryophyte and vascular plant cover on sites with different vegetation composition. Nutrient-poor (NP) Viru and nutrient-rich (NR) Ohtu milled peatlands in Northern Estonia were restored via MLTT between 2006 and 2008. Plant species cover was determined annually or biannually from 2009 to 2018, on permanent plots established during the restoration of both sites. Plant functional type cover was assessed in relation to peat chemical properties and time since restoration. The nutrient status of the restoration site plays a major role in vegetation succession, even if similar restoration methods have been applied. Vascular plant cover, especially evergreen shrubs, increased with time since restoration, while bryophyte (mainly Sphagnum) cover increased at the NP site and decreased at the NR site. At the NR site bryophyte cover decreased with increasing vascular plant cover, while the opposite pattern was observed at the NP site. KEY WORDS: moss-layer-transfer technique, peat nutrient content, peatland restoration, plant functional types, Sphagnum spp.