Potential Forest Distribution over the South Siberian and North Mongolian Mountains Related to Predicted Climate Change by the Midcentury

Abstract

The South Siberian and North Mongolian Mountains have enormous forests potential; however, more and more territories of forests disturbed by cutting and fire appeared during the late twenty years. One more negative phenomenon has been observed in unique dark-needle forests across the South Siberian Mountains: massive dieback of dark-needled forests that was related to climate aridization by many researchers. Our goal was to study predicted climate change impacts on the montane vegetation (altitudinal vegetation belts, AVB) transformation in a changing climate across the South Siberian and North Mongolian Mountains (window 48°–58° N and 80°–120° E). We based on outputs of the general circulation model the of the Computing Mathematics Institute, RAS (INM-CM5-0) and recent climate change scenarios (IPCC 2022) at 2050: the moderate ssp126 and extreme ssp585. Predictions of climate anomalies at 2050 were July temperatures 2–5°С, January temperature 1–4°С and annual precipitation 50–125 mm. According to this climate change, potential AVB may undergo transformation as follows: tundra, subalpine and “podgolets” open forest (under bare uplands) would significantly shrink; montane taiga would shrink 1.7-fold from the moderate scenario and 2.3-fold from the extreme scenario. Dark-needled AVB would remain on the same areas at the expense of subalpine AVB. Potential forest space including forest-tundra and forest-steppe ecotones would change insignificantly: would not change under the moderate scenario and would 10% decrease under the extreme scenario. Forest-steppe AVB would twice increase at the expense of light-needled AVB. One third of forest-steppe would favor broad-leaved forest-steppe. Steppe and semidesert would extend.