Study area

REPEAT works in five European countries with substantial peatland cover: UK, Belgium, the Netherlands, Germany, Poland, and Romania. Study sites are located along a climate gradient from the Atlantic coast to Eastern Poland and arranged in ‘triplets’ of near-natural, drained, and rewetted percolation fens (39 sites). In Poland and Romania, additional sites along eight trophy gradients are studied. Pairs of long-term mown and unmown plots are analysed in the Netherlands, Germany, and Poland.

Main study regions

The Kempen Area, NE-Belgium, consists of an undulating landscape of glacial origin with small and medium-sized rivers whose valleys are filled with peat. Until the 20th century these valleys were only used for hay-making. Especially since 1950s, large parts of the area were heavily fertilized and drained. The small more or less natural remains not used for agriculture suffered from altered hydrology and nutrient inputs. Since 1992 several rewetting projects started, the largest one in the valley of the Zwarte Beek.

The Peene Valley, NE-Germany, contains the largest fen complex in western Central Europe (18,000 ha of peatlands). Most parts have a history of land use but the Peene valley is the least affected, most natural river valley fen in Germany. Land use intensity peaked in 1960-1995 with the establishment of polders, since 1993 restoration measures rewetted 10,000 ha of formerly degraded peatland. Yet peat-forming vegetation is only slowly establishing. Most study sites are mown.

The Biebrza fens, NE-Poland, are one of the largest alkaline groundwater-fed fens in the EU and are characterised by little-modified hydrological conditions. Mowing, once abandoned, has recently been reintroduced for conservation reasons. The Biebrza area serves as a reference for both mesotrophic and eutrophic fens but also contains drained parts, where degradation effects are studied. Rospuda Valley, within the Biebrza catchment, is one of the last remnants of undisturbed low-productive percolation fen, where peat-forming plant communities persist without human management. Rospuda serves as a reference for this type of fens.

The Danube Delta, Romania, is the largest fen area of Southern-Central Europe (5,800 km2 in Romania and 50 km2 in Ukraine). The eutrophic peat layers reach 6m depth. Reed is the dominant species. Vegetation management include domestic mowing for cattle and mechanised cutting in winter for industrial use. The area contains both drained and well-preserved sites and will be used as a reference site for peat accumulation under eutrophic conditions that occur after rewetting highly decomposed peat (c.f. Peene Valley & Kempen).

Other study sites are located in Wales (UK), Arlon (Belgium), Binnenveld and Drentse Aa (The Netherlands), near Kiel (NW-Germany), in Recknitz valley (NE-Germany), in the Mazurian Lakeland, and in the very Northeast of Poland.