Objective To compare the drought adaptive capacity of the canopy and stem of Larix sibirica, to quantify their resilience indices, and to analyze the main driving factors.

Method Tree-ring width samples were collected from two elevation zones in Zaysan District, East Kazakhstan Region, to develop chronologies and to analyze the relationships between radial growth and climate. Drought events were identified by combining growth anomalies with climatic anomalies. Three drought resilience components: resistance, recovery, and resilience, were calculated separately for the tree-ring width index and the Normalized Difference Vegetation Index. Generalized linear models were then used to examine the relationships of canopy resilience with topography, soil properties, and canopy structure, in order to explore how environmental factors shape forest drought resilience.

Result (1) High temperature and drought were the main factors limiting growth. The tree-ring width index declined overall with increasing drought intensity, and growth synchrony also increased. Under wet conditions, radial growth remained above the mean level, and inter-individual variability in growth was markedly greater compared to drought conditions. (2) Drought significantly affected tree resilience. As drought intensity increased, the resistance, recovery, and resilience of the stems of Larix sibirica all declined overall. (3) Elevation was an important environmental gradient influencing stem resilience. Buffered by cooler conditions, high-elevation trees showed higher resistance during drought and greater recovery and resilience after drought than low-elevation trees. Soil bulk density, canopy height, and elevation made the greatest contributions to canopy resistance, recovery, and resilience, respectively. Higher soil bulk density weakened canopy resistance to drought but enhanced recovery in some areas. Taller trees showed higher resistance but recovered more slowly after drought.. Elevation explained 55.45% of the variation in canopy resilience; resilience increased rapidly with elevation, and when elevation exceeded 2 044 m, the canopy was able to recover fully. Greater heat accumulation was unfavorable for maintaining growth during drought but beneficial for post-drought recovery. Stems were more sensitive to drought than canopies, resulting in pronounced differences in resilience between the two.

Conclusion Tree responses to drought were significantly influenced by environmental conditions, with forest resilience being largely shaped by topography, soil properties, and stand structure. Long-term canopy observations can effectively track vegetation growth status. Under climate change, both the frequency and intensity of future drought events are likely to increase, and the lower resilience of low-elevation trees suggests that future droughts may pose risks of forest decline and shifts in species composition.