模拟降水对短花针茅荒漠草原土壤呼吸的影响

Effects of Simulated Precipitation on Soil Respiration of Stipa breviflora Desert Steppe

试验在内蒙古四子王旗短花针茅荒漠草原开展,旨在研究模拟降水对土壤呼吸、土壤温度和土壤湿度的影响。在长期不同放牧平台增设4个不同降水处理(减水50%、自然降水、增水50%和增水100%)。于2016年7月~10月使用土壤碳通量测试仪器(Li-8100)测量土壤呼吸速率,同时用仪器自带的温、湿度探针监测0~10cm土壤温度和0~5cm土壤体积含水量。结果表明:随着降水量的增加,土壤呼吸和土壤湿度呈现显著增加趋势,土壤温度显著降低(P<0.05);7月~10月土壤呼吸速率呈现下降趋势;土壤呼吸与0~10cm土壤温度和0~5cm体积含水量之间存在极显著正相关关系,决定系数分别是0.3117和0.7307(P<0.0001)。结果表明,水分是影响荒漠草原土壤呼吸的关键因子之一。

In order to evaluate the effect of simulated precipitation on soil respiration,soil temperature and soil moisture,the experiment was conducted in Stipa breviflora desert steppe in Siziwang banner,Inner Mongolia.Four precipitation treatments(50% reduced precipitation,natural precipitation,50% and 100% increased precipitation)were set up in long-term different stocking rate grazing plot.The results showed that soil respiration and soil moisture exhibited a significantly increased trend,whereas soil temperature decreased significantly(P<0.05)with the increase of precipitation.The soil respiration revealed a downward trend during the growing season(July to October).There was a significantly positive correlation between soil respiration and 0~10 cm soil temperature and 0~5 cm volumetric water content,in which the decision coefficients were 0.3117 and 0.7307,respectively(P<0.0001).Above results indicated water was one of the key factors determining the soil respiration of desert steppe.