Global surface temperature has increased by 0.74℃ on average since 1850, and the global surface average temperature will increased by 1.8～4.0℃ by the end of the 21st century. Research data indicated that the temperature rising of Qinghai-Tibet Plateau is higher than global average. Therefore, compared to the other permafrost regions, ecosystem of the Qinghai-Tibet Plateau is so sensitive and fragile that it is extremely influenced by the climate change and human activities. 

Temperature controls the rate of many biological and chemical reaction processes, and influences almost all the biological processes. Low temperature and short growing seasons are the main limiting factors for the alpine ecosystem. Therefore, direct temperature rising and indirect growing season lengthening could promote the alpine vegetation growth, and then change the composition and structure of the alpine vegetation community. 

The growth and photosynthetic characteristics of alpine meadow vegetation are important parts of the carbon cycle research, and infrared radiation technology is an ideal method to simulate the climate warming. The infrared heater was used to simulate temperature enhancement in the field focusing on the effects of temperature enhancement on the growth and photosynthetic characteristics of three alpine plants: Polygonum viviparum, Saussurea superb, and Carex atrofusca in order to provide basis for estimating the sensitivity and friability of the meadow ecosystem in the permafrost region on the Qinghai-Tibet Plateau. 

Research results showed that S.pulchra, C. atrofusca and P. viviparum are dominant plant species that constitute alpine meadow of Qinghai-Tibet Plateau. The simulated warming changes the frequency distribution of vegetation and accelerates the growth of three plants and postpones the growing season and green grass season of C. atrofusca and P. viviparum.  

It showed significant differences in the photosynthesis indicators among the plant species, especially among the plots. Research results indicate that the warming can improve the growth and development of the grazing plants in the alpine meadow and prolong their green grass duration resulting in benefit to the livestock production but the vegetation distribution evidently variegated. Besides, the response of species should be taken into consideration when the temperature continues to rise. 

This research is financially supported by the National Natural Science Foundation of China (41301211, 41301210, 41201195). This research is published on the Pratacultural Science (DOI: 10.11829/j.issn.1001-0629.2015-0395)