Pavel Ignashov, Junior Researcher at the Mire Ecosystems Laboratory of the Institute of Biology KarRC RAS presented a poster at the congress in person. The scientist reported the results of a study of the permafrost underlying palsa mires on the Kola Peninsula. At present, these peculiar ecosystems may vanish because of climate change and human impacts. The study was funded by a Russian Science Foundation grant “Spatiotemporal dynamics of palsa mires on the Kola Peninsula as a marker of climate change in the Arctic” (No 22-77-10055). The co-author of the poster and the project leader is Pavel Ryazantsev, Head of the Environmental Monitoring and Modeling Laboratory, Dept. for Multidisciplinary Research KarRC RAS.
Ecologist Pavel Ignashov in front of his poster presented in Nanjing
Palsa mires, or palsas (from Finnish palsa – ‘a bulge of peat in a bog’), are groups of mounds up to several meters high formed by permafrost heaving – when peat is pushed up due to freezing of the underlying layers. Such mires occur only in the Northern Hemisphere, within the sporadic permafrost zone. The Kola Peninsula is the northeastern periphery of the palsa mire distribution in Fennoscandia. Palsas serve as important natural indicators of climate change: global warming is shifting the southern limit of permafrost northward. Estimates of palsa thawing rates can serve as an additional proxy for predicting the consequences.
In this study, the scientists explored palsa mires in different parts of the Murmansk Region, including heavily contaminated industrial wastelands near a smelter in Monchegorsk area. The researchers sought to elucidate the factors behind the phenomenal stability of the frozen mounds under adverse environmental conditions.
– Despite the total loss of vegetation due to acid rain, as well as changes in albedo, these mounds still preserve a fairly hefty core of frozen peat over the long term. This makes these features a unique phenomenon of interest for studying the factors that ensure its resilience to climate warming and increased summer precipitation, – explained Pavel Ignashov.
Audience at the opening session of the World Congress of Soil Science
To pin down the causes of this phenomenon, the project participants compared the structure and properties of peat soils in palsa mires in a technogenic wasteland near Monchegorsk and in an undisturbed mire at the village of Lovozero. The study included geophysical measurements using ground-penetrating radar, core drilling, and analysis of samples from the seasonally thawed layer. As a result, three key factors contributing to palsa stability at the Monchegorsk wasteland were identified. The first one is good drainage, considering that increased peatland moisture promotes permafrost degradation. The second factor for stability is changes in the microclimate. Devegetation has resulted in an increased wind exposure and a reduction in the snow cover. Consequently, peat freezing in winter is augmented, facilitating the regeneration and preservation of the palsa’s frozen core. Finally, the third factor is the impact of acid rain, which caused a loss of peat density and an increase in porosity, thereby enhancing its thermal insulation properties.
Thus, according to the scientists, a paradoxical situation has developed in the wasteland near Monchegorsk: anthropogenic impact has generally been detrimental for the environment, but at the same time created the conditions that support the stability of permafrost in palsa mires. These results are important for understanding the resilience or, vice versa, the vulnerability of ecosystems under climate change and economic activity.
Photos provided by World Congress of Soil Science organizers
