The Effects Of Grazing On Community Characteristics And Water Use Efficiency Of Meadow Grassland In Hulunbeier

The Inner Mongolia is located in arid and semi-arid regions.Water is one of the main limiting factors in its grassland.Grazing is the most widely used method in the grasslands of Inner Mongolia,and to a certain extent,it affects the material circulation and energy flow of grassland ecosystems.Vegetation as an important part of grassland ecosystems,studying the response of water use efficiency to grazing intensity can help use grassland more scientific and effective and provide guidance for the sustainable use of grassland resources.In this paper,the meadow grassland of Hulunbuir was used as an example to conduct experiments in three sites: enclosure-mild grazing-heavy grazing.We study the soil physicochemical properties,community characteristics and evapotranspiration of vegetation,and major plants in different sites.The photosynthetic characteristics,competitiveness and water use efficiency of Leymus chinensis and Stipa baicalensis changed were also studied,and the results were as follows:1.Mild Grazing can increase community diversity,and grazing will reduce community stability.2.Under different grazing intensities,the competitiveness of Leymus chinensis was higher than that of Stipa bengalensis;under mild grazing conditions,the difference was minimal.3.In mild grazing plots the soil moisture content and water storage were the lowest.4.Mild grazing can improve the photosynthetic capacity of Leymus chinensis and Stipa baicalensis.And under grazing conditions,Leymus chinensis had dormancy at midday and Stipa baicalensis reached the maximum photosynthesis rate during that time.5.The highest water use efficiency of the community and the main plant species occurs with the mild grazing plots.