半干旱区土壤微生物呼吸对极端降水的响应  

Response of Soil Respiration to Extreme Precipitation in Semi-arid Regions

作　　者：赵慢 王蕊[1] 李如剑 杜兰兰[2] 吴得峰 孙棋棋[3] 高鑫[2] 郭胜利[1,3,2] 

机构地区：[1]西北农林科技大学资源与环境学院,杨凌712100 [2]西北农林科技大学水土保持研究所,杨凌712100 [3]中国科学院水利部水土保持研究所,杨凌712100

出　　处：《环境科学》2016年第7期2714-2720,共7页Environmental Science

基　　金：国家自然科学基金项目(41371279)

摘　　要：了解土壤微生物呼吸对极端降水的响应对深入理解全球变暖趋势下降水格局的改变对土壤碳循环的影响具有重要意义.于2015年雨季（7~9月）在长武农田生态系统国家野外站,模拟了3种雨季降水量（最高600 mm;平均300 mm;最低150 mm）条件下两种降水形式（每次10 mm：P_（10）,每次150 mm：P_（150））.利用土壤碳通量测量系统（Li-COR,Lincoln,NE,USA）监测不同降水条件下土壤微生物呼吸速率及其土壤水分、温度的变化.相同次降水量条件下,土壤微生物呼吸波动因雨季降水量变化而不同.P_（150）较P_（10）波动剧烈,600 mm降水量下土壤微生物呼吸变异系数分别为36%和33%;300 mm降水量下为28%和22%,150 mm降水量下依次为43%和29%.与P_（10）相比,P_（150）土壤微生物呼吸累积量在600 mm降水量下降低20%;但150 mm降水量下增加22%,300 mm降水量下二者无显著差异.土壤累积呼吸量与水分胁迫时间长短呈显著负相关（R2=0.75）.全球变暖趋势下极端性降水事件增加对土壤微生物呼吸的影响不容忽视.Evaluating the response of soil microbial respiration to extreme precipitation event is significant for a better understanding about the influence of the change of precipitation regime on soil carbon cycling under global warming. A simulated experiment of extreme precipitations was conducted during the rainy season（ July-September 2015） in the Changwu State Key Agro-Ecological Station,Shaanxi,China. The treatments consisted of three total precipitations in rainy season（ 600 mm,300 mm,and 150 mm） and two precipitation regimes（ 10 mm,150 mm; P_（10）,P_（150））. Soil microbial respiration varied differently in the same single rainfall event among three precipitations. The variation coefficient of soil microbial respiration under 600 mm total precipitation was 36%（ P_（150）） and33%（ P_（10））,and 28% and 22% under 300 mm total precipitation,43% and 29% under 150 mm total precipitation. Under 600 mm total precipitation,the cumulative soil microbial respiration under P_（150） was 20% less than that under P_（10）; however,the cumulative soil respiration of P_（150） under 150 mm total precipitation was 22% more than that under P_（10）; and there was no significant difference between P_（10） and P_（150）under 300 mm total precipitation. Therefore,the duration in soil water stress must be considered to estimate soil microbial respirations under extreme precipitations.

关 键 词：极端降水 降水形式 土壤微生物呼吸 土壤水分 水分胁迫 

分 类 号：X144[环境科学与工程—环境科学] X171