Multi‐gradient warming reshapes functional traits and adaptive responses of alpine meadow plants

Abstract Plant functional traits in alpine meadows are critical indicators of ecosystem responses to climate warming, yet dynamic changes in trait networks across warming gradients and their consequences for community functions remain poorly understood. We conducted a 5‐year multi‐level warming experiment (low: +1.3°C; medium: +2.3°C; high: +3.3°C) in a Qinghai–Tibet Plateau alpine meadow, measuring 19 functional traits across three dominant species ( Kobresia pygmaea , Elymus sibiricus , Oxytropis melanocalyx ) to quantify warming effects on trait coordination, community functionality and adaptive strategies. Warming amplitude dictated trait response directions. Critically, trait responses exhibited distinct threshold dynamics: under low warming, highly plastic physiological traits shifted rapidly while stable structural and morphological traits remained largely unaffected, thereby maintaining community functional structure. However, high warming (+3.3°C) triggered severe oxidative stress, evidenced by a 28% increase in malondialdehyde and caused divergent species‐specific adjustments in specific leaf area (SLA). At the community level, acquisitive traits increased under moderate warming but declined at high warming, coinciding with a 34% reduction in functional diversity. Notably, trait networks shifted from energy storage to structural maintenance under warming, with modularity increasing by 41% and connectivity decreasing by 29%, reflecting disrupted trait synergies. Furthermore, warming weakened inter‐trait correlations between physiological and structural traits, indicating that environmental stress disrupted trait coordination and amplified trade‐offs between stress tolerance and growth‐related traits. The coordination of functional traits in alpine meadow plants exhibits a nonlinear response to climate warming, where moderate warming enhances resource acquisition efficiency, while high warming alters trait coordination patterns and diminishes functional diversity. By revealing how the magnitude of warming controls the trade‐off between structural maintenance and physiological performance, the understanding of the mechanism by which warming gradients alter plant ecological strategies has been advanced. These results suggest that alpine meadows may initially buffer moderate warming through trait plasticity, but are at risk of functional instability under extreme warming conditions, providing a critical threshold for predicting ecosystem transitions. Read the free Plain Language Summary for this article on the Journal blog.