Abstract: The radial growth of trees in high-latitude and high-altitude regions of the northern hemisphere usually shows significant unstable and nonlinear divergent responses to climate change as global warming intensifies. The stability of the response of dominant conifers at different altitudes in the Altai Mountains in Northwestern China to climate change remains unknown. With tree-ring samples of Siberian larch (Larix sibirica) collected from high, middle and low altitudes in the middle section of the Altai Mountains, we analyzed the characteristics of three treering width series chronology and the relationship between tree radial growth and climate. The results showed that the radial growth of Siberian larch at high altitude was mainly affected by temperature (including mean temperature, mean minimum and mean maximum temperatures) in April, June, and July. The radial growth of Siberian larch at mid-altitude was mainly affected by mean temperature and mean maximum temperature in May, mean temperature and mean minimum temperatures in June, and precipitation in January and March. However, the radial growth of Siberian larch at low altitude was mainly driven by precipitation in October. In addition, in terms of temporal stability, the limiting effect of temperature on the growth of Siberian larch at high altitude was gradually weakened, while the limiting effect of precipitation on the growth of Siberian larch at middle and low altitudes was increased. Our results provide scientific supports for the management and protection of Siberian larch at different altitudes in Altai Mountains.

Key words: dendroecology, response stability, climate change, Larix sibirica, Altai Mountains.