祁连山亚高山草地土壤呼吸和生态系统呼吸对降雨的响应  

Rainfall effect on soil respiration and ecosystem respiration of a subalpine meadow in Qilian Mountains

作　　者：解欢欢[1] 马文瑛[1] 赵传燕[2] 乔雨[1] 赵宇豪[1] 王方圆[1] 

机构地区：[1]兰州大学生命科学学院/草地农业生态系统国家重点实验室,兰州730000 [2]兰州大学草地农业科学技术学院/草地农业生态系统国家重点实验室,兰州730000

出　　处：《生态学杂志》2016年第11期2875-2882,共8页Chinese Journal of Ecology

基　　金：国家自然科学基金集成项目(91425301)资助

摘　　要：壤水分是影响土壤呼吸的重要因素之一。降雨是扰动土壤水分的重要因子，研究其对土壤呼吸的影响，将有助于理解土壤呼吸机制。本研究选择祁连山天涝池流域亚高山草地为研究对象，通过自然降雨和人工降雨相结合的试验，利用LI-8100土壤碳通量自动测量系统对降雨前后的土壤呼吸（Rs）和生态系统呼吸（Re）进行观测，探讨了亚高山草地土壤呼吸和生态系统呼吸对降雨的响应，并分析了降雨历时和降雨量与呼吸速率的关系。研究发现：短期降雨（降雨历时小于1 h）结束后，土壤呼吸速率减少66.87%，生态系统呼吸速率减少9.88%；连续降雨对呼吸速率的抑制效应表现在降雨后的几个小时内，但在次日及以后时间又对呼吸速率起促进作用，生态系统呼吸和土壤呼吸较降雨前分别增加了1～2倍；降雨历时和降雨量对呼吸速率的抑制强度随降雨历时的延长和降雨量的增加而增强，但当降雨时间达到60 min后，抑制效应减弱，降雨量超过30 mm时，抑制强度减弱；少许降雨会显著刺激呼吸速率，降雨量为0.2 mm时，土壤呼吸速率增加1.81%，生态系统呼吸速率增加41.65%。Soil moisture is one of the most important factors influencing soil respiration. Rainfall plays an important role in disturbing soil moisture. Thus, studying the relationship between rainfall and soil respiration will contribute to understanding the mechanism of soil respiration. In this paper, soil respiration （Rs） and ecosystem respiration （Re） in a subalpine meadow in the Tianlaochi catchment in the Qilian Mountains, Qinghai before and after rainfall were observed using a LI-8100 automatic instrument （LI-COR, Inc., NE, USA） in natural and artificial rainfall experiments. The results showed that Rs and Re decreased by 66.87% and 9.88% after shortterm rainfall （rainfall duration was less than 1 h）, respectively. Continuous rainfall had a negative effect on respiration rate in several hours after the rainfall, but promoted respiration rate the next day and later; Re and Rs increased 1-2 folds respectively compared with the values before rainfall. The intensity of inhibition effects of rainfall duration and rainfall amount on respiration rate increased with the increase of the rainfall duration and rainfall amount, but it would become weaker when the duration was over 60 min or the amount was over 30 mm. A small amount of precipitation would stimulate respiration rate significantly. For example, Rs and Re were increased by 1.81% and 41.65%, respectively when the precipitation was 0.2 mm.

关 键 词：降雨 土壤水分 土壤呼吸 降雨历时 降雨量 

分 类 号：S812[农业科学—草业科学]