中国草原土壤呼吸作用研究进展

中国草原面积约占国土面积的40%,且大都位于生态脆弱区,对气候和环境变化十分敏感,在未来大气CO2调控中有着重要的作用。为增进对中国草原土壤呼吸作用的理解,该文综述了近10年来中国草原土壤呼吸作用的最新研究进展,指出中国草原土壤呼吸作用的研究主要集中在东北平原、内蒙古高原和青藏高原。草原土壤呼吸作用日动态的主导控制因子是温度,季节动态的主导控制因子可以是温度、水分或二者的交互作用,取决于研究地点的限制性环境因子,而年际动态的主导控制因子为水分。草原土壤呼吸作用还存在着巨大的空间变异,年降水和土壤全氮含量是不同类型草原土壤呼吸作用空间异质性的主导控制因子。土壤呼吸作用对全球变化的响应比较复杂,取决于各因子之间相互影响的贡献。现有的土壤呼吸作用模型大多只考虑了水热因子,很少包含土壤因子和生物因子及其协同作用的影响。在此基础上,指出未来中国草原土壤呼吸作用拟加强的研究重点:1)温带荒漠草原土壤呼吸作用研究;2)非生长季土壤呼吸作用研究;3)多时空尺度草原土壤呼吸作用的比较研究;4)草原土壤呼吸作用过程模拟研究;5)草原土壤呼吸作用的遥感监测评估研究。

Review of research advances in soil respiration of grassland in China

Grasslands in China cover vast, continuous areas and account for about 40% of Chinese land area. Most are located in the eco-geographical fragile region, are sensitive to climate change, and play important roles in regulating the carbon dioxide concentration in the atmosphere. Our objective was to review recent studies on soil respiration of grassland in China. Most studies were conducted in Northeast Plain, Inner Mongolia and Tibetan Plateau. Diurnal dynamics of soil respiration are controlled by temperature, seasonal patterns are controlled by temperature and/or water depending on the limiting environmental factors, and inter-annual variability is mainly determined by water. In addition, there is great spatial heterogeneity driven by mean annual precipitation and soil total nitrogen content. Responses of soil respiration to global changes were complicated and depended on the interaction of each factor. Most recent soil respiration models failed to incorporate the modulation of soil and biotic factors and their interaction. Key issues and suggested future research topics are 1) soil respiration in temperate desert grassland, 2) soil respiration during non-growing season, 3) comparison study of grassland soil respiration on different spatial and temporal scales, 4) simulation study of grassland soil respiration and 5) remote sensing of grassland soil respiration.