Wang Zongming, Zhang Bai, Zhang Shuqing, Li Xiaoyan, Liu Dianwei, Song Kaishan, Li Jianping, Li Fang, Duan Hongtao
Department of RS and GIS, Northeast Institute of Geography and Agricultural Ecology, Chinese Academy of Sciences, Changchun, Jilin Province, China.
Environ Monit Assess. 2006 Jan;112(1-3):69-91. doi: 10.1007/s10661-006-0312-5.
Agricultural activities, especially reclamation, are considered major threats to the wetland ecosystems in Sanjiang Plain, the largest concentrated area of the freshwater wetlands in China. In the past decades, the area of the cultivated land and its grain production have been increased at the cost of wetlands shrinkage. The large-scale land reclamation severely affected the ecosystems in this region. However, such effects at the regional scale are seldom evaluated quantitatively. We used three datasets of LANDSAT MSS and/or TM imagery to estimate the area changes and the transition of land use types from 1980 to 2000. We also valued changes in ecosystem services delivered by each land category using value coefficients published by Costanza et al. Sensitivity analysis suggested that these estimates were relatively robust. Finally, the contribution of various ecosystem functions was ranked to the overall value of the ecosystem services in this study. According to our estimates, the total annual ecosystem service values in Sanjiang Plain have declined by about 40% between 1980 and 2000 (156284-182572.18 million US dollars in total over 20 years). This substantial decline is largely attributed to the 53.4% loss of wetlands. For individual ecosystem functions, waste treatment, water supply and disturbance regulation account for more than 60% to the total ecological values. During those two decades, the contribution of disturbance regulation, cultural and recreation decreased, while the contribution of water regulation, nutrient cycling, food production, raw materials and climate regulation increased during the same period. We also put forward a few proposals concerning the future land use policy formulation and sustainable ecosystems. They are adjusting the 'food first' agricultural policy, establishing more nature reserves for wetlands, creating systems for the rational use of water, harnessing the degraded cultivated land and encouraging eco-tourism.
农业活动，尤其是开垦，被认为是对中国最大的淡水湿地集中区——三江平原湿地生态系统的主要威胁。在过去几十年里，耕地面积及其粮食产量的增加是以湿地萎缩为代价的。大规模的土地开垦严重影响了该地区的生态系统。然而，这种区域尺度的影响很少进行定量评估。我们使用了三个陆地卫星MSS和/或TM影像数据集来估计1980年至2000年土地利用类型的面积变化和转变。我们还利用科斯坦萨等人公布的价值系数对每种土地类型提供的生态系统服务变化进行了评估。敏感性分析表明这些估计相对可靠。最后，在本研究中对各种生态系统功能对生态系统服务总价值的贡献进行了排序。根据我们的估计，三江平原的年度生态系统服务总价值在1980年至2000年间下降了约40%（20年间总计减少了1562.84亿至1825.7218亿美元）。这种大幅下降主要归因于湿地面积减少了53.4%。对于单个生态系统功能而言，废物处理、供水和干扰调节占总生态价值的60%以上。在这二十年中，干扰调节、文化和娱乐的贡献下降，而同期水调节、养分循环、食物生产、原材料和气候调节的贡献增加。我们还就未来土地利用政策制定和可持续生态系统提出了一些建议。它们包括调整“粮食优先”的农业政策、建立更多的湿地自然保护区、创建合理用水系统、治理退化耕地以及鼓励生态旅游。
