ASSESMENT OF HYDROTHERMIC CONDITIONS OF EXPOSURE-RELATED FOREST-STEPPE OF INNER ASIA ON THE BASE OF DIRECT AND INDIRECT PARAMETERS

Hydrothermic conditions of exposure-related forest-steppe of Inner Asia have been analyzed. The slope-specific vegetation distribution in study region can be explained by topographycontrolled coming solar radiation which led to differentiated soil temperatures and soil water supply. Soil temperature was differ on different aspects and slope inclinations, and also connected with size of forest patches. There was a buffering effect of forests on soil temperature, as indicated by cooler soil temperatures in the warm season and warmer soil temperatures in the cold season. Soils in the forest sites and steppe sites freeze almost simultaneously, but experience a delay in thawing of approximately 14, 19 and 25 days for birch, pine, and larch forest, respectively. Various ecological niches formed by topography and soil conditions characterized by high coenotic diversity of forest-steppe landscapes of Inner Asia.Исследования проведены при поддержке грантов РФФИ 13-04-91180, 16-54-53057 и в рамках государственного задания по теме № АААА-А17-117011810036-3

Rapid warming accelerates tree growth decline in semi-arid forests of Inner Asia

Forests around the world are subject to risk of high rates of tree growth decline and increased tree mortality from combinations of climate warming and drought, notably in semi-arid settings. Here, we assess how climate warming has affected tree growth in one of the world's most extensive zones of semi-arid forests, in Inner Asia, a region where lack of data limits our understanding of how climate change may impact forests. We show that pervasive tree growth declines since 1994 in Inner Asia have been confined to semi-arid forests, where growing season water stress has been rising due to warming-induced increases in atmospheric moisture demand. A causal link between increasing drought and declining growth at semi-arid sites is corroborated by correlation analyses comparing annual climate data to records of tree-ring widths. These ring-width records tend to be substantially more sensitive to drought variability at semi-arid sites than at semi-humid sites. Fire occurrence and insect/pathogen attacks have increased in tandem with the most recent (2007-2009) documented episode of tree mortality. If warming in Inner Asia continues, further increases in forest stress and tree mortality could be expected, potentially driving the eventual regional loss of current semi-arid forests

Rapid warming accelerates tree growth decline in semi-arid forests of Inner Asia.

Forests around the world are subject to risk of high rates of tree growth decline and increased tree mortality from combinations of climate warming and drought, notably in semi-arid settings. Here, we assess how climate warming has affected tree growth in one of the world's most extensive zones of semi-arid forests, in Inner Asia, a region where lack of data limits our understanding of how climate change may impact forests. We show that pervasive tree growth declines since 1994 in Inner Asia have been confined to semi-arid forests, where growing season water stress has been rising due to warming-induced increases in atmospheric moisture demand. A causal link between increasing drought and declining growth at semi-arid sites is corroborated by correlation analyses comparing annual climate data to records of tree-ring widths. These ring-width records tend to be substantially more sensitive to drought variability at semi-arid sites than at semi-humid sites. Fire occurrence and insect/pathogen attacks have increased in tandem with the most recent (2007-2009) documented episode of tree mortality. If warming in Inner Asia continues, further increases in forest stress and tree mortality could be expected, potentially driving the eventual regional loss of current semi-arid forests