Impacts of Large Herbivores on Permafrost Soil Carbon Storage

• Main Authors: Windirsch, Torben, Grosse, Guido, Ulrich, Mathias, Forbes, Bruce C, Göckede, Mathias, Wolter, Juliane, Macias-Fauria, Marc, Olofsson, Johan, Zimov, Nikita, Strauss, Jens
• Format: Conference Object
• Language: unknown
• Published: 2021
• Subjects: Chersky; permafrost; Thermokarst; Tundra; Siberia
• Online Access: https://epic.awi.de/id/eprint/56877/; https://epic.awi.de/id/eprint/56877/1/Windirsch_2021_Poster.pdf; https://hdl.handle.net/10013/epic.828e7eab-86fe-4659-bcb0-6ff1fe3f39a8

In our study we examined the effects of large herbivorous animals on soil carbon storage in a permafrost landscape in northeastern Siberia. To assess the impact of those animals on the soil carbon storage, we examined soil profiles and permafrost cores from areas with different grazing intensities within landscape units, more specifically a drained thermokarst basin and the surrounding uplands. To do so, we chose our study sites in the Pleistocene Park near Chersky, as this area provides known animal densities and fenced areas, which allowed us to compare intensively grazed, extensively grazed, and non-grazed sites on a small spatial scale. We found significantly higher carbon (TOC) values at those sites with intensive animal grazing, compared to non-grazed sites, especially within the active layer. Also, vegetation was shifted on intensively grazed sites from shrubby tundra vegetation to grasslands. In addition, active layer depth was smaller on grazed sites. We conclude that the animals improve carbon storage and permafrost stability by changing the vegetation and removing or trampling down snow in winter, both of which led to colder ground conditions and hence reduced organic matter decomposition. This could be a hint to possible strategies to locally prevent permafrost thaw by rewilding or an intensification of animal husbandry in tundra areas.