Researchers have created various climate models to assess global warming, but there are many uncertainties associated with these calculations. For instance, it is very difficult to predict the development of greenhouse gas emissions globally. In northern Finland, global warming does not pose a similar threat as in southern Finland, where it is expected to increase several risks associated with forest damage.
However, human activity may have an even greater impact on forests and peatlands than global warming. Enhanced forest management, such as using fertilizers, can be used to increase tree growth and carbon sequestration. By adapting forest management, it is also possible to reduce soil emissions from forests and drained peatlands.
Especially for spruce, however, climate change increases many risks for damage simultaneously, including damage caused by strong winds, European spruce bark beetles and the tree decay fungi Heterobasidion.
“Lower felling volumes increase carbon sinks in forests and peatlands more than higher felling volumes. However, very low felling volumes can also increase the risk of damage as the forest ages,” Peltola says.
“Increased risk for damage makes decision-making complicated.”
Drying of peatlands may already have begun
Finland is a country of not only forests, but also peatlands. They, too, play an important role in mitigating global warming. Peatlands store around 500 gigatonnes of carbon, which is equivalent to more than half of the current atmospheric carbon.
In Finland, peatlands cover almost one third of the country’s area, making them the most important carbon storage.
“However, if conditions change, they can end up releasing huge amounts of carbon into the atmosphere. This is why their role is significant, both for Finland and globally,” Professor Eeva-Stiina Tuittila explains.
In peatland, water level controls the entire ecosystem, the distribution and function of plants and microbes, as well as ecosystem services, such as climate regulation.
“Forests are able to regulate their loss of water to atmosphere in evapotranspiration better than peatlands do. In peatlands, drying might be already ongoing. Further, it is not a linear process: even short spells of drought may cause changes in peatland vegetation.”
Changes taking place in peatlands have been studied by experiments modifying temperatures and water levels. The project Restoration of Low-productive Drained Peatlands - With Well Targeted Site Selection and Good Practices Towards Safeguarding of Soil Carbon Storage and Improved Functional Biodiversity is funded by the Recovery and Resilience Facility of the EU through the Ministry of Agriculture and Forestry, and it is coordinated by UEF.
“In Finland, peatlands have been restored on a rather small scale since 1980, but with the EU’s increasingly ambitious climate targets and goals to restore and conserve nature, there is an urgent need to identify the optimal areas and methods for restoration, and the effects sought,” Tuittila says.
“In another peatland restoration project, Return of Sphagnum, we are, for the first time, testing the transplantation of sphagnum moss in the restoration of a forestry drained peatland. The aim is to speed up the return of peatland vegetation to the area under restoration and thus to ensure that carbon sequestration begins also on disturbed surfaces devoid of vegetation, such as in the ditches.”
“Moss transplantation is thought to bring in methane-oxidising bacteria that can reduce methane emissions from the peatland.”