Genxu Wang, Ju Qian, Guodong Cheng, Yuanmin Lai
Key Laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, PR China.
Sci Total Environ. 2002 May 27;291(1-3):207-17. doi: 10.1016/s0048-9697(01)01100-7.
A study of carbon (C) storage in the 0-0.75-m profile of soils subtending various types of grasslands on the Qinghai-Tibetan Plateau showed that the organic carbon content of the 1,627,000 km2 of such lands in the region reaches 33.52 Pg of C. Organic carbon is mainly stored in the meadow and steppe soils of the Plateau, which combined, represents 23.2 Pg of C stored in organic form. This represents 23.44% of China's total organic soil-stored carbon and 2.5% of the global pool of soil carbon as of 1996. Carbon emissions from the grassland soils were estimated based on the two major modes of emission: (i) natural soil respiration and (ii) shifts in net C flux to/from soil due to land-use changes and their potential influence on organic matter decomposition. Annual soil respiration-driven CO2 emissions from the grassland soils of the plateau reached 1.17 Pg C year(-1), accounting for 26.4% of China's total soil respiration and 1.73% of global soil respiration. Because the grassland area accounts for 1.02% of the global terrestrial land and 16.9% of China's total terrestrial land, this CO2 emission rate is significantly higher than the country's mean annual rate (approx. 4.2 Pg C year(-1)) and even higher than the global mean rate (approx. 68 Pg C year(-1)). In the last 30 years, approximately 3.02 Pg C have been emitted from the grassland soils of the plateau due to land-use changes and grassland degradation. The total CO2 emissions rate from the grassland soils of the plateau reached 1.27 Pg C year(-1). Protecting grasslands on the Qinghai-Tibetan Plateau is of great importance in limiting global climate change.
一项对青藏高原不同类型草地0至0.75米土层碳（C）储量的研究表明，该地区162.7万平方千米此类土地的有机碳含量达33.52Pg C。有机碳主要储存在高原的草甸土和草原土中，二者合计，以有机形式储存的碳达23.2Pg C。这占1996年中国土壤有机碳总储量的23.44%，占全球土壤碳库的2.5%。基于两种主要排放模式估算了草地土壤的碳排放：（i）自然土壤呼吸；（ii）土地利用变化导致的土壤净碳通量变化及其对有机质分解的潜在影响。高原草地土壤因土壤呼吸导致的年CO₂排放量达1.17Pg C year⁻¹，占中国土壤呼吸总量的26.4%，占全球土壤呼吸的1.73%。由于草地面积占全球陆地面积的1.02%，占中国陆地总面积的16.9%，该CO₂排放速率显著高于中国年均排放速率（约4.2Pg C year⁻¹），甚至高于全球平均速率（约68Pg C year⁻¹）。在过去30年里，由于土地利用变化和草地退化，高原草地土壤大约排放了3.02Pg C。高原草地土壤的总CO₂排放速率达1.27Pg C year⁻¹。保护青藏高原的草地对于限制全球气候变化至关重要。
