陆地生态系统碳循环及其机理研究的地球信息科学方法初探

A method of geo-information science for studying carbon cycle and its mechanism of terrestrial ecosystems

针对陆地生态系统碳汇 /源的时空格局、碳循环过程的驱动机制及未来情景等前沿科学问题 ,提出陆地碳循环研究的地球信息科学方法 ,采用陆地生态系统碳通量 /储量与碳循环过程的综合网络观测、生物过程的适应性实验研究以及河流碳输运过程研究为支撑系统的自下而上途径、与以土地利用 /土地覆被变化和对地观测数据生态参量反演为基础的自上而下研究途径、经相互验证和尺度转换模型实现有机结合的研究方法 ,开展综合观测、调查、比对分析、模拟和评价研究 ,把握陆地生态系统碳循环的格局与过程规律 ,辨析自然和人为因素对陆地生态系统碳循环过程的影响 ,探讨全球气候变化条件下陆地生态系统碳循环过程的演变趋势。

There exists about 1.4～1.7GtC missing sink in the global carbon budgets. The missing sink might happen in terrestrial biosphere and coastal continental shelf. However, this guess is lack of support from scientific observation data and research methods. Progress in geo-information science is paving way for studying carbon cycle and its mechanisms of terrestrial ecosystems. To address the scientific issues such as temporal and spatial pattern of terrestrial ecosystem carbon sink, and driving mechanism and scenarios of carbon cycle, this paper proposes a method of geo-information science for studying carbon cycle of terrestrial ecosystems.Bottom-up approach and top-down approach are combined by means of scaling models. The bottom-up approach is based on observations of comprehensive network of carbon storage and carbon cycle process of terrestrial ecosystems, adaptive experiments of biological processes, and researches on carbon transportation processes of rivers. the top-down approach is based on detecting land cover change and retrieving ecological parameters by using satellite data. Retrieval models of carbon budgets are developed by means of the capacity of satellite remote sensing that can frequently supply surface information of geographical processes and ecological processes. On the basis of analyzing data-at-points collected by stations of Chinese Ecosystem Research Network, stations of Chinese Forest Ecosystem Research Network, and observation stations of HINAFLUX, combined with the retrieval models, a numerical simulation model of terrestrial ecosystem carbon cycle is constructed by means of surface theorem, grid generation method and grid computing technique. Pattern and process of carbon cycle are to be simulated; natural and human impacts on carbon cycle of terrestrial ecosystems are to be analyzed; and evolution trends of carbon cycle process of terrestrial ecosystems are to be discussed under the condition of global climate change.