Monitoring of high-altitude terrestrial ecosystems in the Altai Mountains

Abstract

The Aktru mountain glacier basin (the North-Chuya Ridge, Altai Mountains) is a region of highly important ecosystems. We have been performing a monitoring of the autotrophic component of the basin ecosystems for the last 16 years. The primary indicator species with the most clearly defined response to climatic changes are Siberian stone pine and Siberian larch with their individuals and populations. The ecosystem level of the monitoring includes that of old forests, ecotone ecosystems, and ecosystems on the new moraines. The old forests have remained stable for about 1000 years. The reasons for this stability are the long lifespan and the long generative stage of stone pine and larch, their ability to produce several growth forms, optimal ecological conditions of the basin for these species and high a-diversity of the old forests. The treeline has moved up by 100-200 m for the last 150 years and by 40-90 m for the last 40 years, mostly because of an invasion of stone pine to the ecotone. The primary successions on the moraines are also relatively stable, although at present only stone pine has been involved in the successions. No regeneration of larch has been observed for the last 16 years in the entire basin.