Herstel van verdroogde beekdalvenen. Effecten van vernatting op biogeochemie en vegetatie (Restoration of drained peatlands. Effects of rewetting on biogeochemistry and vegetation)

“Een eeuwenlange historie van antropogene ontwatering en versnippering heeft diepe sporen achtergelaten in het Europese beekdallandschap. Ongestoorde beekdalvenen komen nauwelijks meer voor, en de venen die nog resteren hebben vaak grote veranderingen doorgemaakt in biogeochemie en vegetatie. Veenherstel door grootschalige vernatting is nu de enige weg voorwaarts, maar het is de vraag of deze maatregel toereikend is voor biogeochemisch herstel.”

(Citaat: Emsens, W.J., van Diggelen, R., Aggenbach, C.J.S., Smolders, A.J.P. – Herstel van verdroogde beekdalvenen.Effecten van vernatting op biogeochemie en vegetatie – Landschap 38(2021)3, p.157-165)

“Rewetting is a first crucial step in the restoration of longterm drained groundwater-fed peatlands (fens). However, a complete recovery of local biogeochemical conditions and vegetation is unlikely within the short term (< few decennia). Drainage has triggered the irreversible loss of soil organic matter, the mobilization of nutrients, and the loss of target species of small sedge and brown moss communities. Although rewetted fens are often dominated by tall sedges and reeds rather than low-productive small sedge communities, this is already an improvement compared to the vegetation under drained conditions. Currently, it remains uncertain whether species-rich small sedge and brown moss communities will recover over a longer time span of several decades to centuries. More rigorous restoration measures, including removal of the degraded top soil or species re-introduction, may be required to facilitate recovery." (Citation: Emsens, W.J., van Diggelen, R., Aggenbach, C.J.S., Smolders, A.J.P. - Restoration of drained peatlands. Effects of rewetting on biogeochemistry and vegetation - Landschap 38(2021)3, p.157-165)