Warming counteracts grazing effects on the functional structure of the soil microbial community in a Tibetan grassland

Publication date: Available online 27 February 2019Source: Soil Biology and BiochemistryAuthor(s): Li Tang, Lei Zhong, Kai Xue, Shiping Wang, Zhihong Xu, Qiaoyan Lin, Caiyun Luo, Yichao Rui, Xiangzhen Li, Ming Li, Wen-tso Liu, Yunfeng Yang, Jizhong Zhou, Yanfen WangAbstractGrazing intensity and global warming are expected to increase in the forthcoming decades, with uncertain consequences for their interaction on grassland ecosystems and their functions. We investigated the effects of warming, grazing and their interaction in a factorial warming (+1.2–1.7 °C) and grazing (moderate intensity with ca. 50% vegetation consumption) experiment in a Tibetan alpine meadow on microbial communities by studying functional genes involved in soil carbon and nitrogen cycles, using GeoChip technology. Our results showed that microbial functional gene structure and abundances were largely affected by the interactive effect of grazing and warming, rather than the main effect of warming or grazing. Compared to the control, grazing alone significantly increased the functional gene alpha diversity, changed the overall functional community structure, and increased the abundances of C fixation, C degradation, N mineralization and denitrification genes, likely due to the stimulating impact of urine and dung deposition. Warming alone did not change these microbial properties, possibly related to the unchanged soil nutrient status. Despite an increase in soil NO3− concentrations and the deposit...
Source: Soil Biology and Biochemistry - Category: Biology Source Type: research