Author(s)

Yuejun Fan^1,2, Xiyun Chang², Deping Zhao^3*, Xiangyang Hou^1*, Xin Li⁴

¹Grassland Research Institute of Chinese Academy of Agriculture Science, Hohhot, China.
²Qinghai Vocational and Technical College of Animal Husbandry and Veterinary Science, Xining, China.
³Northwest Institute of Plateau, Chinese Academy of Science, Key Laboratory of Restoration Ecology of Cold Area in Qinghai Province, Xining, China.
⁴Qinghai University, Xining, China.

Although soil respiration is the largest contributor to C flux from terrestrial ecosystems to the atmosphere, our understanding of its characteristics and carbon budget in alpine meadow is rather limited because of extremely geographic situation. This study was designed to examine soil CO₂ efflux characteristics of diurnal and seasonal variation, thus obtaining estimates of carbon balance of Kobresia pygmaea meadow in Qinghai-Tibet plateau. The results showed that the soil respiration of diurnal and seasonal rate changed little in growing season and was mainly affected by temperature, and single peak curve that showed afternoon appeared. Composite model which was set by soil respiration rate, soil moisture content and temperature (atmospheric temperature and soil temperature) could explain better the variations of soil respiration rate. The variation range of Q₁₀ ranged from 1.28 to 2.34, which was sensitive to temperature in green-up period and late growth stage, and decreased in growth peak period. Meanwhile, during the growing seasons the observed amount of annual carbon fixation via primary production for Kobresia pygmaea meadow ecosystem was about 120.21 g C·m^-2·a^-1. The carbon dioxide output via soil heterotrophic respiration was about 37.54 g C·m^-2·a^-1. So carbon budget had more input than output. The Kobresia pygmaea meadow ecosystem has stronger potential to absorb carbon dioxide, it was a sink of atmospheric CO₂, and the plant community had a net carbon gain of 82.67 g C·m^-2·a^-1.

Soil Respiration, Kobresia pygmaea Meadow, Carbon Balance/Budget, Qinghai-Tibet Plateau

Fan, Y. , Chang, X. , Zhao, D. , Hou, X. and Li, X. (2020) Study on Soil Respiration Characteristics and Carbon Balance of Kobresia pygmaea Meadow in Qinghai-Tibet Plateau, China. Journal of Environmental Protection, 11, 636-647. doi: 10.4236/jep.2020.118038.