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青藏高原草地碳动态对区域乃至全球碳循环都有非常重要的影响.采用生态系统碳循环模型—CENTURY模型4.5版本探讨了青藏高原草地生态系统土壤有机碳(0～20cm)在1960～2002年间的年际动态变化特征及其区域分异特征.CENTURY模型模拟的地上部分生物量与土壤表层有机碳与实测结果有较好的一致性.从1960～2002年,8个典型草地生态系统土壤有机碳含量表现出明显年际的波动,变化幅度随生态系统土壤有机碳含量增加而增大;青藏高原草地有机碳总量和主要草地生态系统有机碳总量也呈现出明显的年际变化,而以1990～2000年期间的年际变化幅度最大,在这期间主要生态系统有机碳总量都呈现出先上升而后迅速下降的变化.土壤有机碳含量的区域分布特征表现出从东南向西北降低的地带性分异,同时在东北和东南表现出非地带性分异特征.该研究表明:近40年来青藏高原典型草地生态系统随气候变动有比较敏感的响应,同时,在假定生态系统生理特性不变的条件下,近10年来的气候变动增加了青藏高原草地土壤有机碳的积累和排放速度.
The grassland carbon dynamics on the Tibetan Plateau has a very important impact on the regional and even global carbon cycle. Using the Carbon Cycle Model of the Ecosystem-CAPENTON Model 4.5, the soil organic carbon (0-20 cm) of the grassland ecosystem in the Tibetan Plateau was studied from 1960 to 2002 Interannual dynamic changes and their regional differentiation characteristics.The aboveground biomass biomass simulated by theENTURY model is in good agreement with the measured soil organic carbon content.From 1960 to 2002, eight typical grassland ecosystems soil organic carbon The content of total organic carbon in the grassland showed a significant interannual variation with the interannual fluctuation in the ecosystem, and the magnitude of the change increased with the increase of soil organic carbon in the ecosystem. The interannual variability ranged from 1990 to 2000. During this period, the total organic carbon in the main ecosystem showed the first increase and then the rapid decline.The regional distribution of soil organic carbon showed a zonality decreasing from southeast to northwest Differentiation, at the same time in the northeast and southeast showed non-zonal differentiation characteristics.The study shows that: nearly 40 years of the typical Tibetan Plateau Ecosystems with climate change have sensitive response, at the same time, under the assumption of constant physiological characteristics of ecosystem conditions, changes in the climate of the past 10 years to increase the accumulation and discharge speed plateau grassland soil organic carbon.