The northernmost peatlands of Finnish Lapland are home to palsa mires, unique permafrost landforms. However, a recent study indicates these landforms are under threat due to climate change.
A study from the University of Eastern Finland reveals a significant reduction in the area of palsa mires due to climate change. While the permafrost core continues to thaw year after year, the active layer thickness remains largely unchanged. This surprising finding underscores the complex impacts of climate change on permafrost conditions.
A Glimpse into Palsa Mires
Palsa mires, the primary permafrost landforms found in Fennoscandia, are undergoing significant changes due to climate change. With the warming climate, these permafrost peatlands are expected to vanish, leading to increased carbon dioxide and nitrous oxide emissions.
Decoding the Impact of Climate Change
A long-term study conducted at the University of Eastern Finland has spotlighted the dramatic reduction in the area of palsa mires. The research found that over the span from 1959 to 2021, the palsa area at the observation sites had decreased by over 75%.
The Enigma of the Active Layer
Despite the diminishing palsa area, the study observed that the active layer thickness did not significantly increase during the monitoring period. This layer, which thaws in summer and freezes in winter, has remained fairly stable, presenting a complex scenario for researchers.
Surprising Effects of Snow Cover
The study also revealed that the timing of lasting snow cover’s onset could impact the active layer thickness. Warmer autumns delay the onset of lasting snow cover, consequently reducing the active layer thickness in palsa sites.
The study offers a foundation for future research into the intricate relationship between climate change and permafrost conditions. Understanding the mechanisms behind the stability of the active layer despite permafrost thawing could open new avenues for study. Moreover, the impact of snow cover on permafrost could be further explored, helping to predict the future of these unique ecosystems under climate change.