Upward Expansion of Trees and Shrubs Leads to Alpine Tundra Contraction and Local Extinction of Species in the Southern Urals

Abstract

Alpine tundra at the top of high mountains and the treeline ecotone are both highly sensitive to modern climate change. In the Southern Urals alpine tundra occupies relatively small areas as the mountain ranges are quite low, while the treeline there is relatively high. The summit Dalniy Taganay, due to its marginal position in the mountain range and the direct onsite long-term monitoring, gives unique data on the intensity of upward expansion of woody vegetation for the last century and its consequences on the ecosystem level. By comparing old topographic maps and satellite images, repeated landscape photographs, and analyzing the age structure of forest stands it was determined that since the 1960s the upward expansion of open and closed forests had resulted in 72% decrease of unforested areas including alpine tundra. The intrusion of junipers to alpine tundra communities has been detected as well. Since 1990 the changes in various types of alpine tundra have been revealed by repeated observations. Since 2008 at the summit of Dalniy Taganay the ground-dwelling invertebrates have shown a significant decrease in the abundance of certain species and the endemic ground beetle Carabus karpinskii Kryzhanovskij & Matveev has not been recorded since 2022. Only the number of red ants in alpine tundra has shown a fourfold increase and typical forest beetles appeared. We could trace in detail not only the movement of forest higher into the mountains but also the changes in alpine and treeline ecotone’s vegetation and animal communities with local extinction of specific species. The presented results can be used to adjust the models of climate-driven transformation for other similar mountains, where the area of alpine meadows or tundra is critically small. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.