Research Progress on the Effects of Livestock Grazing Behavior on Soil-plant System in Alpine Grassland

Livestock grazing is one of the most important ways to utilize alpine grassland, which affects alpine grassland ecosystems through their behaviors including feeding, trampling and excreta return. However, the effects of different livestock behaviors on the soil-plant system of alpine grassland and the mechanism of the effects are still unclear. In this study, we synthesized the effects of the above three livestock behaviors on vegetation growth characteristics, soil physicochemical properties, soil nutrient effectiveness and ecosystem productivity, through analyzing the difference regarding the basic characteristics of the three main behaviors, and their interactions with soil properties and plant growth. We note that the three behaviors of livestock grazing are vital part of the nutrient and energy cycle of alpine grassland ecosystem. Feeding can affect the nutrient cycle by changing the plant biomass and its distribution pattern. Trampling mainly affects plant growth and development by changing the soil physical properties, while the magnitude of these effects is closely related to grassland type, soil texture and water content. In contrast, excreta return is an important nitrogen source in alpine grassland, and dung and urine nitrogen inputs affect grassland soil fertility and ecosystem productivity to varying degrees by altering soil carbon and nitrogen content and nutrient effectiveness. Our findings would help to deepen the understanding of the processes and mechanisms of livestock grazing behavior on the soil-plant system of alpine grassland and benefit adaptive management and sustainable development of alpine grassland ecosystems.