Petukhov I.A., Andreev A.V., Bazha S.N., Bogdanov E.A., Danzhalova E.V., Drobyshev Yu.I., Rupyshev Yu.A., Khadbaatar S. Comparative Analysis of Vegetation Structure in Mountain Forest Ecosystems of Northern Mongolia (Based on the Model Polygons) // Ecosystems: ecology and dynamics. No 4. 2025. P. 5-62. | Abstract | PDF | Reference

 

 

In this research we conducted large-scale mapping (1:10,000-1:50,000) and description of natural ecosystems at the junction of two belts, forest and forest-steppe mountain, in the Selenga River Basin, Northern Mongolia. Part of broader studies on the forest growth conditions of the Lake Baikal Basin, this research took place in 2019 and 2022 across 4 model polygons: Zelter in the eastern Dzhida Range, Chandmani-Under in the central Eastern Khuvsgul Region, Zunkhara in the foothills of Western Khentii Highlands, and Selbe in the southwestern Khentii Upland.

“Selbe” and “Chandmani-Under” encompass 3 forest vegetation altitudinal belts: mountain-taiga, sub-taiga, and forest-steppe. The low-mountain “Zelter” and “Zunkhara” lack the mountain-taiga belt. Distinctively, unlike most mountain forest areas in Mongolia where only 1-2 coniferous species typically form the primary forest stands, the indigenous forest types in the upper Selbe River Basin are comprised of 4 coniferous species: Pinus sibirica, Larix sibirica, Pinus sylvestris and Picea obovata. In “Chandmani-Under” and “Zelter”, Larix sibirica is the dominant coniferous species, while in “Zunkhara” it is Pinus sylvestris and Larix sibirica.

The large-scale mapping data from the model polygons clearly demonstrated a regular altitudinal succession of altitudinal belts, transitioning from mountain-taiga forests at higher elevations of middle-mountain slopes, through sub-taiga, to forest-steppe communities bordering the steppe belt. As aridity increases from north to south, the lower boundaries of these altitudinal belts, including forest vegetation zones, shift upwards. For instance, taiga forests on north-facing slopes of “Selbe” are located above 1600 m a.s.l. (and above 1650 m on the south-facing slopes), whereas in “Chandmani-Under”, situated over 200 km further north, such forests descend steep north-facing slopes to below 1250 m.

The forest-covered area of the model polygons exceeds 70%. However, there is a significant proportion of secondary pyrogenic small-leaved forests, primarily dominated by Betula pendula subsp. mandshurica and Populus tremula. These secondary birch stands and early-stage post-fire successional forests account for 20-24% of the total forest area in “Selbe” and “Chandmani-Under”, over 50% in “Zelter”, and as high as 98% in “Zunkhara”, where indigenous mountain pine-larch and larch-pine sub-taiga forests are entirely absent.

Analysis of the maps depicting forest ecosystems with destroyed indigenous stands at various stages of recovery, alongside their legends characterizing topo-ecological development conditions, enables an assessment of forest degradation scales. This provides a basis for determining natural and technical restoration possibilities, methods, and volumes, and for selecting the most suitable forest cultures for restoration based on the dominant species in the original stands.

Funding. This work was carried out within the framework of the scientific program of the Joint Russian-Mongolian Integrated Biological Expedition of the Russian Academy of Sciences and the Mongolian Academy of Sciences, and the state task of the Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, topic No. FFER-2024-0025 “Biogeocenology and Ecosystem Evolution”.

Keywords: mountain forest ecosystems, topo-ecological conditions, altitudinal belts, forest-forming species, secondary stands, large-scale mapping.

DOI: 10.24412/2542-2006-2025-4-5-62

EDN: ADAUJU