藏北典型高寒草原土壤微气候对增温的响应

Response of Soil Microclimate to Warming in Alpine Steppe,Northern Tibetan Plateau

土壤微气候的改变会影响到一系列的生态系统过程,研究增温条件下土壤微气候变化特征将有助于了解气候变暖对草地生态系统水热条件的影响。利用开顶箱(open-top chamber,OTC)方法研究增温条件下藏北典型高寒草原土壤微气候变化特征。结果表明:藏北典型高寒草原土壤温度和土壤湿度存在明显的日变异和季节变异;增温使得空气年均温增加3.2℃,土壤年均温增加5.2℃,增温效果显著;增温可以显著提高土壤温度,值得注意的现象是非生长季的增加幅度大于生长季的增加幅度;增温对土壤湿度的影响具有明显的季节性,冬季增温会显著增加土壤湿度,而夏季增温会显著降低土壤湿度。研究结果可为变化气候条件下高寒地区水热状况研究提供依据。

The change in soil microclimate could affect many ecosystem processes, and study on soil microclimate＇ s response to warming will be helpful in climate change project. In this study, open-top chamber （OTC） was em- ployed to investigate the response of soil microclimate to warming in a alpine steppe in Northern Tibetan Plateau. The results showed that： there was apparent diurnal and seasonal variation in soil microclimate in the alpine steppe; OTC elevated annual average air temperature by 3.2~C, soil temperature by 5.2~C ;OTC could significantly elevate soil temperature, more increase in non-growing season than in growing season; OTC could significantly elevate soil moisture in winter, while reduce the soil moisture in summer. warming, and the results are helpful in studying the effect of This paper analyzed the response of soil microclimate to climate change on hydrothermal regime in alpine region.