Alpine peatlands under pressure: 86 percent bear traces of human intervention

TVS News AI, editorially supervised, presents Alpine peatlands under pressure: 86 percent bear traces of human intervention.

At 86.1 percent of 590 examined peatland sites in Germany, Austria and Switzerland, researchers have found visible traces of human intervention. Roads, drainage ditches and agricultural use are affecting these sensitive ecosystems across the Alps – often unnoticed, because official maps only inadequately reflect the real situation.

What the study specifically found

An international team involving the University of Göttingen evaluated satellite imagery and terrain data from 2019 to 2023. The findings have been published in the journal Communications Earth & Environment. Most frequently, the researchers found evidence of infrastructure such as roads or buildings – at 59 percent of sites. They discovered drainage ditches at 46.4 percent, and agricultural use such as mown areas or grazing tracks at 26.6 percent. At 16.8 percent of sites, trees already covered at least 30 percent of the peatland area.

Often several of these changes occur together – and that is precisely the problem. Peatlands only form where the soil remains permanently wet. When the water table drops due to ditches or roads, oxygen enters the soil, the peat decomposes faster, releasing climate-damaging CO₂ in the process.

Why the maps no longer match reality

A peatland near Salzburg illustrates how strongly the landscape is outpacing the maps. Official documents record 15.5 hectares of peatland there. The satellite model, however, only identified a small portion as peatland. Aerial images from 2007 to 2024 show new roads and a growing network of drainage ditches – in 2007 the area still appeared largely undisturbed.

"We initially thought the model was wrong. But then we discovered that these 'too small' peatlands were mostly located on areas with visible disturbances such as new drainage ditches or paths," explains first author Marian Schönauer from Mendel University in the Czech city of Brno, according to a statement from the University of Göttingen.

Across all sites, the model missed an average of 60 percent of the officially mapped peatland area on sites with visible disturbances. On areas without such indicators, it was 43.4 percent. Particularly small peatlands were also harder to detect. Drainage ditches or infrastructure alone, however, had no statistically detectable impact on the error rate – the decisive factor was above all increasing vegetation cover by trees and agricultural use.

How the researchers proceeded

Optical imagery from the European Sentinel-2 satellite provided the largest contribution to detection: differences in vegetation cover can be identified based on light reflection. In addition, the researchers combined radar imagery and terrain data. However, the method reaches its limits precisely with densely vegetated or small peatlands – for reliable statements about the actual condition, on-site investigations remain necessary.

What this means for conservation

Without reliable information about altered peatland areas, conservation measures can hardly be planned in a targeted way – particularly endangered areas could simply be overlooked. Conversely, the model also provided indications of suspected sites not yet captured at all, which need to be verified on the ground. Simon Drollinger from the University of Göttingen sums up the significance: "Alpine peatlands are small habitats with great ecological importance: they store carbon over the long term, regulate the water balance and provide habitat for specialised animal and plant species." The team's recommendation: monitor stocks regularly via satellite, then investigate conspicuous sites specifically on the ground – for drainage, vegetation changes and possible damage.