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Global climate change is expected to increase the frequency and intensity of extreme droughts. Researching tree growth responses to drought helps assess the potential of forest adaptation and ecological stability under changing climate conditions. Here, we investigated tree growth resilience components (resistance, recovery, and resilience) to extreme drought events of two mainly distributed species, Pinus tabulaeformis and Picea wilsonii, on the Gannan Plateau, the Eastern Tibetan Plateau. Tree-ring width data from 510 trees at 20 plots along the elevation gradients were employed to analyze the tree resilience components at the individual tree level. The results showed that P. tabulaeformis had a lower growth resistance and a higher recovery capacity to drought than P. wilsonii, which might be related to the different strategies for combating drought of the two species. In addition, the tree growth response of P. tabulaeformis to drought changed significantly along the elevation gradient due to its higher drought sensitivity than that of P. wilsonii. Overall, the long-term correlation between tree growth and drought index, tree size, and soil water content had implications for tree growth resistance, recovery, and resilience. Given the observed differences in tree growth resistance to drought among different species and environmental conditions, a well-thought-out and tailored strategy would better support forest management on the Gannan Plateau. [ABSTRACT FROM AUTHOR]

• Seasonal water uptake differed among different tree species. • Deep-rooted tree species had lower growth resistance to drought. • Shallow-rooted tree species was more adaptative to seasonal precipitation areas. • The root structure and deep soil water availability were the key factors influencing the drought resistance of trees. Understanding the water use patterns of different tree species and their adaptability to drought is urgently needed due to global warming. In this study, we investigated the seasonal water uptake patterns of Pinus tabulaeformis and Picea wilsonii on the eastern Tibetan Plateau using stable isotope methods. In addition, tree ring width data was used to evaluate the radial growth resistance of the two species to drought in 2022. The focus was on identifying species differences in water uptake patterns during drought spells and radial growth resistance to drought. The results showed that although Pinus tabulaeformis could increase water uptake from deeper soil layers during drought spells, the radial growth resistance to drought was significantly lower (p < 0.001) than that of Picea wilsonii due to the limited water content in the deep soil layers. In contrast, Picea wilsonii had higher resistance and adaptations to drought based on rapid access to water resources from seasonal precipitation with denser fine roots. Overall, shifting water sources to deeper soils during drought spells was not always effective in alleviating drought stress, but the root structure and deep soil water availability were the key factors influencing the drought resistance of trees. The findings had significant implications for decision-making on the species suitability of plantation projects under future climatic change. [ABSTRACT FROM AUTHOR]