模拟降水对短花针茅荒漠草原土壤呼吸的影响

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。

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

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.