温度和氮素输入对青藏高原3种高寒草地土壤氮矿化的影响

目的]研究温度和氮素输入对青藏高原3种高寒草地土壤氮矿化的影响。方法]选取海北高寒草甸、那曲高寒草原和当雄高寒湿地3种典型高寒草地生态系统类型为研究对象,采集表层0～10cm土壤,在实验室内进行土壤氮矿化培养试验。结果]温度对青藏高原3种高寒草地土壤氮矿化影响显著,其中高寒草原土壤氮矿化速率随着温度的升高而升高,而高寒草甸和高寒湿地的土壤氮矿化速率随着温度的升高呈下降趋势。氮素输入对高寒草甸土壤氮矿化的影响不显著,而氮添加显著促进了高寒草原和高寒湿地的土壤氮矿化速率。青藏高原3种不同高寒草地类型间的土壤氮矿化速率存在显著差异。结论]温度和氮素输入对青藏高原3种高寒草地的土壤氮矿化有不同表现的显著影响,且温度和氮素输入对青藏高原高寒草地土壤氮矿化的影响依赖于生态系统类型。

Effects of Temperature and Nitrogen Input on Nitrogen Mineralization in Alpine Soils on Tibetan Plateau

Objective] The study aimed to investigate the effects of temperature and nitrogen input on nitrogen mineralization in alpine soils on the Tibetan Plateau.Method]An incubation experiment in the laboratory was conducted using three alpine soils.These soils were collected from the top 10 cm depth in three grassland types:alpine meadow in Haibei,alpine steppe in Naqu and alpine wetland in Dangxiong.Result] Temperature significantly affected nitrogen mineralization in alpine soils of three grassland types.The mineralization rate in alpine steppe soil rose with the rise of temperature,while the mineralization rate in the alpine meadow soil and alpine wetland soil decreased with the rise of temperature.Nitrogen input had no significant effect on nitrogen mineralization in the alpine meadow soil,but significantly increased nitrogen mineralization in the alpine steppe soil and the alpine wetland soil.Grassland types significantly affected nitrogen mineralization in alpine grasslands.Conclusion] The effects of temperature and nitrogen input on nitrogen mineralization in alpine soils on the Tibetan Plateau were significant.And those different effects depended on different types of grassland.