Hydrology LIFE: Bringing water back to Finland’s wetlands

Finland has some of the most extensive peatlands in Europe, covering 9.3 million ha and making up around a third of the country's total land area. But with half these valuable habitats drained and severely degraded, Hydrology LIFE has worked to restore more than 100 of these wetland sites to their former glory.

Even as we mark World Wetlands Day , many of Finland's peat bogs remain frozen in the icy embrace of winter. The arrival of spring in a couple of months, however, will reveal just how the project has transformed the landscape.

The project team has rewetted peatland and bogs, restored small streams and improved lakes used by water birds. In total, 5 800 ha of peatland - equivalent to over 8 000 football fields - have been restored between 2017-2023, along with 42 km of streams and 4 lakes.

Vital wetland vegetation has been gradually returning. Higher water levels provide a home for birds such as the Ruff (Calidris pugnax), classified Near Threatened in Europe by the IUCN Red List. Wetlands allow booming insect populations and attract other wildlife, including bats.

'Hydrology LIFE showed on a large scale that restoration is a powerful tool in safeguarding wetlands that are so valuable for both biodiversity and us humans,' says Tuomas Haapalehto, from Metsähallitus, the state-run enterprise responsible for Finland's parks and wildlife which coordinates the project. 'Years ago, the mires were drained for forestry. Drainage ditches dried them out and encouraged tree growth on drained sites and peatlands nearby.'

To rewet the mires - many of which are within Natura 2000 sites - the project dug new ditches to allow water to flow into dried-up mires, and blocked others that had been used to drain the peatlands in the first place. Volunteers helped to improve the flow of small streams in these areas by creating gravel beds to slow down the water and adding rocks and dams to guide their path. 14 lakes were restored by dredging and creating small islands for nesting birds.

The project team admits that peatland vegetation has been slow to return but they are hopeful of eventual success. Similar restored sites they studied have taken up to a decade to return to their natural state. 'Peat-forming sphagnum mosses proliferated in the years following restoration and were the most obvious winners, whereas woodland floor mosses, which had become abundant as a result of drainage, declined,' says Haapalehto.

A study by researchers at the University of Turku in Finland, one of the project partners, also found that bats are among those most immediately benefiting from the wetland restoration work . 'The study revealed that the activity of bats increased markedly in restored wetlands, presumably because the bats could find more insects,' says Anna Blomberg, one of those who conducted the research. 'The most detected bat species were the northern bat and different species of mouse-eared bats.'

The Hydrology LIFE project has contributed to the implementation of the EU's Habitats Directive, the Birds Directive, the Biodiversity Strategy for 2030, the Nature Restoration Regulation and the Water Framework Directive.