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土壤呼吸是陆地生态系统通过根系呼吸和微生物呼吸向大气中释放CO2的过程。研究土壤呼吸的时空格局,将有助于构建区域尺度土壤呼吸定量评价模型,也可提高预测未来气候变化情境下的典型生态系统、区域以及全球尺度碳平衡状况的能力。本文整合了中国区域土壤呼吸的主要研究成果,分析了温度敏感性(Q10)和土壤呼吸(Rs)的统计特征和区域差异,定量评价了中国区域Rs的时空格局及其在中国和全球碳平衡中的作用。通过以上分析本文得出以下主要结论:①不同生态系统类型的土壤呼吸的Q10表现为森林>农田>草地,气候越寒冷,土壤呼吸Q10越大,并且中国区域的Q10值相对于其他国家偏低;②Rs具有明显的季节变异,不同生态系统类型的Rs表现为森林>农田>草地,并且,中国区域Rs低于全球Rs;③月尺度上Rs随着经纬度发生明显的季节变异,随着经度的增加,Rs的季节变幅也逐渐增加;④1995-2004年中国区域Rs的年总量的平均值为3.84 PgC,占全球土壤CO2排放的比例4.78%。
Soil respiration is the process by which terrestrial ecosystems emit carbon dioxide into the atmosphere through root respiration and microbial respiration. Studying the spatio-temporal pattern of soil respiration will help to build a quantitative assessment model of soil respiration at a regional scale and also improve the ability to predict carbon balances at typical ecosystems, regions and at global scales for future climate change scenarios. This paper integrates the main research results of soil respiration in China, analyzes the statistical characteristics and regional differences of temperature sensitivity (Q10) and soil respiration (Rs), and quantitatively evaluates the spatio-temporal pattern of Rs in China and its impact on carbon balance in China and the world In the role. Through the above analysis, the main conclusions of this paper are as follows: ① Q10 of soil respiration of different ecosystem types is forest> farmland> grassland. The colder the climate, the larger the Q10 of soil respiration, and the Q10 value of China is lower than that of other countries ; ②Rs had obvious seasonal variation, and Rs of different ecosystem types showed forest> farmland> grassland, and Rs in China was lower than that of global Rs; ③ Rs showed obvious seasonal variation with latitude and longitude on monthly scale, The annual amplitude of Rs also increased gradually. (4) The average annual total Rs in China from 1995 to 2004 was 3.84 PgC, accounting for 4.78% of the global soil CO2 emissions.