Responses to climate change in radial growth of Picea schrenkiana along elevations of the eastern Tianshan Mountains, northwest China

•Drought was main factor limiting tree growth from warm-dry to warm-wet climate.•Schrenk spruce had not divergent response with climate factors driving radial growth.•Trees along elevation gradients had different strategies to cope with drought stress.•Decline of radial growth at higher elevation was faster than the lower elevation.•Further climate warming will more seriously impact on forests of high elevation.