Siberian larch is better adapted to stress in wet-stressed areas than in drought-stressed areas

Abstract

With climate change, the frequency and intensity of wet and dry events are increasing, as is the uncertainty of their impact on tree growth. There have been studies on the effects of wet and dry conditions on tree growth, but there is a lack of comparisons of tree adaptation strategies to different types of wet and dry events in heterogeneous environments. Therefore, we explored differences in the response of tree radial growth to different types of wet and dry events using data on tree ring widths of Siberian larch (Larix sibirica) in the Altai Mountains (west) and Mongolian Plateau (east) of Central Asia. The results showed that western tree radial growth was significantly negatively correlated with precipitation and Standardized Precipitation Evapotranspiration Index (SPEI), and significantly positively correlated with mean temperature. The radial growth of trees in the east was significantly and positively correlated with precipitation and SPEI, and significantly and negatively correlated with mean temperature. Trees in wet-stressed areas are less resistance to composite cold-wet events than to ordinary wet events. Trees in drought-stressed areas are less resistance to composite hot-drought events than to ordinary drought events. Trees in the wet-stressed area recovered to normal growth levels in the first year after both ordinary wet and compound cold-wet events, and trees in the drought-stressed area failed to recover after both ordinary drought and compound hot-drought events, but then experienced compensatory growth. Thus, climate warming had a positive effect on radial growth of trees in the wet-stressed areas and a negative effect on radial growth of drought-stressed trees. Forest management should be based on the different adaptation strategies of larch to climatic stresses in heterogeneous environments.