中国自然生态系统对气候变化的脆弱性评估

生态系统的脆弱性已经成为气候变化影响评估和适应性管理的关键问题。本文介绍和分析了生态系统的脆弱性、敏感性和阈值的概念,中国生态环境的敏感带和脆弱性,脆弱性评估和中国生态系统脆弱分布以及自然生态系统的可持续性和适应减缓对策。自然生态系统对气候变化脆弱性评估仍存在许多问题和不确定性,迫切需要在以下领域开展研究:自主开发新一代气候变化对生态系统影响综合评估模型(特别是双向耦合模型)、加强相关野外长期观测实验、开展适应性与可持续发展示范工程的研究等。

Assessment of vulnerability of natural ecosystemsin China under the changing climate

Vulnerability of natural ecosystems has become a key issue both in assessing the impact of climate change and in planning the adaptation to climate change. In the paper, we elucidated the concepts of vulnerability, sensibility and threshold, analyzed distributions of the ecolble for global warming will change. The productivity and carbon flux of terrestrial ecosystems are also highly sensitive to climate change. The Net Primary Productivity (NPP) of terrestrial vegetation has been increasing since the 1980s in China. Annual Net Ecosystem Productivity (NEP) varies between 0.32 and 0.25 Gt C a~-1, wit h a mean value of 0.07 Gt C a~-1. Terrestrial ecosystems in China are cur rently a carbon sink, but the carbon uptake rate ogical sensitive zones, vulnerability of natural ecosystems and adaptation to climate and ecosystem changes in China. Numerous studies show that natural ecosystems are high sensitivity to climate change, particularly in the transitional zones (i.e. ecotones). The first-class sensitive zone in China is the region be tween the east of Inner Mongolia and the southeast of Tibetan Plateau. The climate zones and vegetation zones will produce a northward or westward shift, and the proportion of vegetations is one of the factors responsimay diminish as anticipated with the rapid warming of climate in this century. Seven regions vulnerable to climate change in China account for 20% of the whole country, in which five are in the west of China. The natural hazards are associated with climate change such as drought, fire, pest infestationetc. Excessive use of resources will increase the vulnerability of ecosystems. Applications of some measures are helpful to the adaptation to the climate change and mitigation of the vulnerability. However, there are still high uncertainties in assessing the vulnerability of natural ecosystems, many issues warrant further studies.