Soil respiration after six years of continuous drought stress in the tropical rainforest in Southwest China

Publication date: Available online 9 August 2019Source: Soil Biology and BiochemistryAuthor(s): Liguo Zhou, Yuntong Liu, Yiping Zhang, Liqing Sha, Qinghai Song, Wenjun Zhou, D. Balasubramanian, Gnanamoorthy Palingamoorthy, Jinbo Gao, Youxing Lin, Jing Li, Ruiwu Zhou, Sai Tay Zar Myo, Xianhui Tang, Jin Zhang, Peng Zhang, Shusen Wang, John GraceAbstractClimate models predict that droughts will increase in Southeast Asia, yet little is known about how soil respiration (Rs) and its components heterotrophic respiration (Rh) and autotrophic respiration (Ra) will change following drought years. To clarify this issue and to detect underlying mechanisms, we conducted a 2-year field experiment in the seventh and eighth year of long-term artificially droughted plots within a tropical rainforest in Xishuangbanna, southwest China. We separated Rh and Ra by trenching and we measured dissolved organic carbon in the soil and microbial biomass. In average, the drought stress, reduced through-fall by 50%, reduced fine root biomass by 36%. Although Ra declined by 35%, active inorganic N and Rh increased by 31% and 29%. Further, the coefficient of determination (R2) between soil microbial community composition, mainly, group-specific phospholipid fatty acid and the variation of Rh was among 17%–59% during the dry and rainy season of 2018. However, changes in dissolved organic carbon, microbial biomass carbon and nitrogen, ammonium nitrogen, were inconsistent with the increase in Rh. There was ...
Source: Soil Biology and Biochemistry - Category: Biology Source Type: research