Ecological Adaptation of Two Dominant Conifer Species to Extreme Climate in the Tianshan Mountains

With global warming, the frequency, intensity, and period of extreme climates in more areas will probably increase in the twenty first century. However, the impact of climate extremes on forest vulnerability and the mechanisms by which forests adapt to climate extremes are not clear. The eastern Tianshan Mountains, set within the arid and dry region of Central Asia, is very sensitive to climate change. In this paper, the response of Picea schrenkiana and Larix sibirica to climate fluctuations and their stability were analyzed by Pearson's correlation based on the observation of interannual change rates of climate indexes in different periods. Additionally, their ecological adaptability to future climate change was explored by regression analysis of climate factors and a selection of master control factors using the Lasso model. We found that the climate has undergone significant changes, especially the temperature, from 1958 to 2012. Around 1985, various extreme climate indexes had obvious abrupt changes. The research results suggested that: (1) the responses of the two tree species to extreme climate changed significantly after the change in temperature; (2) Schrenk spruce was more sensitive than Siberian larch to extreme climate change; and (3) the resistance of Siberian larch was higher than that of Schrenk spruce when faced with climate disturbance events. These results indicate that extreme climate changes will significantly interfere with the trees radial growth. At the same time, scientific management and maintenance measures are taken for different extreme weather events and different tree species.

Automated summary

With global warming, it is expected that the frequency, intensity, and period of extreme climates will increase in many areas. However, the impact of climate extremes on forest vulnerability and the mechanisms of forest adaptation to extreme climates are not well understood. In this study, the response of two tree species, Picea schrenkiana and Larix sibirica, to climate fluctuations and their adaptability were analyzed based on long-term climate data. The results showed that extreme climate changes significantly affected the growth of the two tree species, with Schrenk spruce being more sensitive and Siberian larch having higher resistance to extreme climate events.