Restoration of water quality and biology in two rewetted cut-over peatlands

Restoration of wetlands is of high priority in Europe. After-use of peat excavation areas, including rewetting, is one such measure and has been investigated at two sites in Sweden. Water quality changed after rewetting with fairly stable or higher pH and concentrations of base cations. Nutrient concentrations were initially high but decreased after a number of years. Oxygen contents in water were similar to ordinary small lakes, also with occasional depletion in bottom layers at stagnation periods. The colonization of vegetation was rapid at Västkärr site but slower at Porla site, also with start of Sphagnum colonization. The bottom fauna consisted of high numbers of species and individuals the very first years after rewetting. After a few years the bottom fauna decreased to lower levels but is now slowly rising.