Biological communities in small water bodies recover from restoration – but very slowly

The impacts of restoration will be studied in a research project led by the Finnish Environment Institute (Syke). The environmental impacts of peatland restoration will be studied through time. to help assess the long-term effects of the restoration measures used.

In Finland, the environmental effects of the restoration of drained peatlands have been monitored to some extent, but there is little previous research on the restoration of abandoned peat production areas.

"If large areas of an ecosystem have been destroyed, where and how do the organisms come back? There is no certainty when they return, or if they return at all," says Timo Muotka, Professor of the University of Oulu. "However, the new EU restoration targets are forcing us to be able to demonstrate the success of restoration. Historically, we know that, for example, restoration of former timber floating channels has been relatively successful, but the recovery of large catchments downstream of peat production areas is likely to be much slower."

The study compares the biodiversity of water bodies downstream of peat production areas restored for about 15, 10 or 5 years ago to those restored very recently (less than one year ago), and to near-natural reference systems. "We assume that waters below areas restored 15 years ago should show clear signs of achieving a natural state," says postdoctoral researcher Kaisa-Riikka Mustonen. "First, hydrology, such as natural water level variation and seasonal flood dynamics should return. Next, the water chemistry should recover, and biological recovery will come last."

"The status of small water bodies in Finland is bleak, and it is difficult to find a place where the impact of extensive drainage does not confound the research design," says Muotka. That's why the study sites for this project are located immediately downstream of the restored peatlands.

"Previous studies have examined the effects of restoration usually only for a very short time after the restoration activities. However, long-term monitoring over several years is crucial to get a complete picture of the recovery, as greenhouse gas emissions, water chemistry, and vegetation change over time," says researcher Mirkka Visuri from Syke.

The project is led by The Finnish Environment Institute Syke and involves the Natural Resources Institute Luke and the University of Oulu. Preliminary results are expected next spring. The project is funded by the European Union's Just Transition Fund (JTF) through the ELY Centre of North Ostrobothnia.