本研究在内蒙古典型草原开展实验,主要针不同放牧强度对植物光合生理特征的影响。实验包括三个主要部分：光合日动态、光响应和叶绿素荧光。结果表明:1) 实验植物没有受到环境胁迫；禁牧是一个防止草原退化的有效方式；适度的放牧可以改善植物的光合作用，但最理想的放牧强度因物种不同而变化；2) 不同的放牧方式会影响土壤水分含量，同时可以影响植物群落的结构；3) 2014年夏天的干旱是一个特殊情况，放牧方式对草原植物光合生理的影响有待于进一步实验和分析。

The experiments were carried out in typical steppe of Inner Mongolia, which was aimed at the response of the plant photosynthetic physiological characteristics to the different grazing intensity. The experiments included three main parts: daily dynamic changes of photosynthesis, light response and chlorophyll fluorescence. The results show: 1) the experimental plants were not in stress environment. Forbidden grazing is a good way to prevent degeneration, and moderate grazing can improve the photosynthesis of some plants. The best grazing intensity is not a stable situation, which depends on the different species; 2) different grazing types can affect the soil moisture and also can affect the structure of plant communities; 3) the drought in the summer of 2014 was a special situation in plant photosynthetic physiological research. This study should have further experiments and analyses.