Effect of exogenous carbon addition and the freeze-thaw cycle on soil microbes and mineral nitrogen pools1

2017 3rd International Conference on Environmental Science and Material Application

生态环境科学;材料科学

Hu, Xia^1,2 ; Yin, Peng^1 ; Nong, Xiang^1,2 ; Liao, Jinhua^1

College of Life Science, Leshan Normal University, Leshan

614004, China^1

Bamboo Diseases and Pests Control and Resources Development Key Laboratory of Sichuan Province, Leshan Normal University, Leshan

614004, China^2

关键词: Eastern Tibetan plateau;    Freeze-thaw cycles;    Laboratory simulation;    Response mechanisms;    Soil enzyme activity;    Soil microbial biomass;    Soil mineral nitrogen;    Temperature amplitude;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/108/3/032046/pdf
DOI  :  10.1088/1755-1315/108/3/032046

来源: IOP

【 摘 要 】

To elucidate the alpine soil process in winter, the response mechanism of soil mineral nitrogen and soil microbes to exogenous carbon (0 mg C, 1 mg C, 2 mg C, 4 mg C and 8 mg C•g-1dry soil) and the freeze-thaw cycle (-2 °C, -2 ∼ 2 °C, -20 ∼2°C) were studied by laboratory simulation. The freeze-thaw treatment had no significant effect on microbial biomass nitrogen and the number of bacteria. The soil mineral N pool, the number of fungi, and enzyme activities were obviously affected by the freeze-thaw cycle. A mild freeze-thaw cycle (-2∼2°C) significantly increased the number of fungi and catalase activity, while severe freeze-thaw cycle (-20∼2°C) obviously decreased invertase activity. The results suggested that both the freeze-thaw rate and freeze-thaw temperature amplitudes have a strong effect on soil microbial dynamics in the alpine zone in winter. The results showed that exogenous carbon addition significantly decreased soil NO3-N and NH4+-N contents, increased soil microbial biomass, the number of microbes, and soil enzyme activities. The results showed that microbial growth in the eastern Tibetan Plateau was somewhat limited by available C. It may represent a larger potential pulse of soil nutrient for alpine plants in the next spring, and may be instrumental for plant community shifts under future climate change predictions due to the possible increased litter addition.