Degradation legacy and current water levels as predictors of carbon emissions from two fen sites

Drainage-induced shifts in physicochemical peat properties are irreversible on a decadal time span. We investigated whether carbon emissions from fen peat can be estimated using two proxies: current water levels and peat properties (as affected by drainage history, i.e. degradation legacy). We collected bare peat monoliths from a long-term drained and an undrained fen. In a crossed design, half of the monoliths was kept wet and the other half was drained. Highest carbon dioxide (CO2) emissions came from the originally undrained peat under low water levels (607 mmol m-2 d-1). Overall, CO2 emissions were primarily determined by drainage history, with 141 % higher emissions from the originally undrained peat. In addition, low current water levels correlated with 42 % higher emissions. Highest methane (CH4) emissions were measured in the originally undrained peat under high water levels (123 mmol m-2 d-1). Overall, CH4 emissions were primarily determined by current water levels, with 430 % higher emissions under high water levels. In addition, the originally undrained peat had 180 % higher emissions. The lower C efflux from originally drained peat correlated with lower concentrations of methanogens and of easily-degradable carbon substrate (cellulose). We conclude that substrate limitation in long-term drained fens ensures low baseline carbon emissions, which provides opportunities for renewed carbon sequestration by rewetting

What is a Macrophyte Patch? Patch Identification in Aquatic Ecosystems and Guidelines for Consistent Delineation

Schoelynck J, Creëlle S, Buis K, De Mulder T, Emsens W, Hein T, Meire D, Meire P, Okruszko T, Preiner S, Roldan Gonzalez R, Silinski A, Temmerman S, Troch P, Van Oyen T, Verschoren V, Visser F, Wang C, Wolters J, Folkard A, in press. . Ecohydrology & Hydrobiology. DOI 10.1016/j.ecohyd.2017.10.00

Restoration of Central European fens – the larger context

Fens are groundwater-fed wetlands that once covered substantial surfaces in Central Europe. They deliver important services to society including carbon fixation, water buffering, biodiversity and nutrient retention. Nowadays most of these wetlands have been lost or highly decreased in size or quality. This has led to enormous losses in water buffering capacity and biodiversity and huge releases of carbon and nutrients. Despite all this negative effects of drainage even today freshwater wetlands still face the highest loss rate of all European habitat types. On the other hand, many countries have started restoration programs to get at least some of the functions of the lost wetlands back. The present contribution will address factors that affect the sustainability of wetland restoration in relation to spatial scale and landscape connectivity. We will translate these findings into practical knowledge, aimed at evaluating restoration scenarios focusing on the optimisation of different services in restored fen systems. We will evaluate to what degree there are synergies possible between restoration activities aimed at increasing ecosystem resilience and those that seek to enhance other goals.peerReviewe

Quantification of water purification in South African palmiet wetlands

Despite the importance of water purification to society, it is one of the more difficult wetland ecosystem services to quantify. It remains an issue in ecosystem service assessments where rapid estimates are needed, and poor-quality indicators are overused. We attempted to quantify the water purification service of South African palmiet wetlands (valley-bottom peatlands highly threatened by agriculture). First, we used an instantaneous catchment-scale mass balance sampling approach, which compared the fate of various water quality parameters over degraded and pristine sections of palmiet wetlands. We found that pristine palmiet wetlands acted as a sink for water, major cations, anions, dissolved silicon and nutrients, though there was relatively high variation in these trends. There are important limitations to this catchment-scale approach, including the fact that at this large scale there are multiple mechanisms (internal wetland processes as well as external inputs) at work that are impossible to untangle with limited data. Therefore, secondly, we performed a small field-scale field survey of a wetland fragment to corroborate the catchment-scale results. There was a reasonable level of agreement between the results of the two techniques.We conclude that it appears possible to estimate the water purification function of these valley-bottom wetlands using this catchment-scale approach