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Satellite images reveal positive effects of restoration in northern hemisphere peatlands

An international research team led by Aalto University has just published the first large-scale analysis based on long-term satellite data on the effects of peatland restoration. The paper is in the journal Environmental Research Letters.

The lead author of the study, Postdoctoral Researcher Iuliia Burdun from Aalto University, explains that NASA's satellite image time series were analyzed over a period of more than 20 years.

The researchers examined key climate variables of peatlands: temperature, vegetation, and albedo, that is, the proportion of sunlight the surface reflects into space.

The study showed clear changes roughly a decade after restoration measures began.

"The albedo and temperature of restored areas began to resemble intact peatlands rather than drained peatlands, across nearly all the studied areas," Burdun summarizes.

The study covered 72 areas in Finland, Estonia, Latvia, Lithuania, the United Kingdom, Canada, and the United States—countries where peatlands cover a significant portion of the land area.

The sites included wooded and open peatlands, peat extraction areas, and peatlands drained for agriculture.

The effects of restoration on vegetation were not as fast or consistent as the changes in temperature and reflectivity. According to Burdun, there are several reasons for this.

"Albedo and temperature change more quickly as the peatland becomes waterlogged, but the return of vegetation takes longer. Simply blocking drainage ditches is often not enough—other measures are also needed. In forested mires, this might mean cutting down trees, while in bare peat extraction areas, it could involve planting moss, for example," she explains.

More detailed information on ecosystem health

When a peatland is drained, the peat dries out and the carbon stored in it is released into the atmosphere. Degraded peatlands are estimated to cause about 5% of global greenhouse gas emissions.

Undrained peatlands play an important role as carbon sinks and as habitats that support biodiversity. Finland and many other countries are launching large-scale peatland restoration projects, driven in part by the EU Restoration Regulation.

About one-third of Finland's land area consists of peatlands, roughly half of which have been drained. Restoration is a large and costly undertaking, and monitoring its success and impacts through field measurements alone is impossible, emphasizes Professor Miina Rautiainen from Aalto University, who led the study.

"To support peatland restoration decisions and actions, both in Finland and globally, we urgently need diverse information on the characteristics of natural mires and the effects of restoration. Satellite imagery play a key role in helping us understand ecosystem changes across large geographical areas."