Vulnerability and adaptation of the larch forest in Eastern Siberia to climate change

Abstract

The most widely distributed coniferous forests in the world are the larch forests. In the Russian Federation they occupy 27.6 x 106 ha. In Siberia, the larch species Larix russica generally grows west of the Yenissei River, and Larxi gmelinii grows to the east. The morphological and physiological features of L. gmelinii make it possible for this species to grow in the far north of eastern Siberia, where climate conditions are more severe: The range of air temperature fluctuations in this region is more than 100°C, from 38°C down to 64°C below zero. One of the major adaptions to unfavorable soil conditions is provided by a specific feature of root formation in L. gmelinii in which the apex central root dies off at the permafrost border and a root system develops in upper soil layers. The major larch vulnerability factors are natural and anthropogenic fires and damage caused by insects, which become more frequent with hot and dry weather. The consequences of projected global warming could be both positive and negative for larch forests. Permafrost melting may result in improved soil nutrition in the areas the larch forests occupy, yet the frequency of forest fires and damage by pathogens are likely to increase. Global warming is expected to cause forest dieback and increased areas of steppe in the southern regions of eastern Siberia.