Abstract: Climate change may bring huge potential risks to alpine ecosystems of Qinghai-Tibet Plateau. Leaf traits can reflect the process and mechanisms of plant response to climate change. In this study, a free-air infrared heating method was used to simulate temperature increasing in Haibei alpine meadow in Qinghai. The effects of temperature increasing on eight leaf traits of eight species in an alpine meadow were examined. The results showed that five traits of some plants, including leaf size, vein length per area, vein mass per leaf mass, leaf mass per area, and leaf carbon isotope discrimination, changed significantly after eight years of warming, while the change of carbon-nitrogen content and carbon-nitrogen ratio was not significant. Leaf size was more sensitive to temperature changes than other traits. Increasing temperature had a significant long-term effect on leaf traits, but there were significant differences in the direction and degree of the responses of different traits. There were differences in the effects of warming on leaf traits of species with different distribution types and leaf vein types. Plants showed diverse responses to environmental changes, which were manifested in the differential response of the same traits of different plant species to climate. At the same time, they are also manifested in the coordinated responses of different traits of the same species to climate change.

Key words: climate change, alpine meadow, warming, leaf trait, synergistic response, Qinghai-Tibet Plateau