三江平原北部生态系统服务价值的时空演变

Temporal and spatial changes in ecosystem service values in the northern sanjiang plain

以三江平原北部地区2市5县为研究区,采用生态系统服务价值评估方法对1954—2009年间三江平原北部地区生态系统服务价值进行估算,以期全面分析土地生态系统服务价值随时空变化的特点。结果表明:(1)1954—2009年间三江平原北部地区的不同土地利用类型面积变化显著,农田变化速度最快,其次为湿地,人口数量的增加及保证粮食增产是土地利用变化的主要驱动力。(2)1954—2009年三江平原北部地区生态系统服务价值总量逐渐减少,共减少779.51亿元。长期的土地垦殖是三江平原北部地区生态系统服务价值减少的主要驱动因素。(3)就各土地利用类型生态系统服务价值而言,55年间除农田生态系统和水域生态系统生态服务价值是增加外,其余各生态系统服务价值均在减少。湿地生态系统服务价值减少值最大,其次为林地生态系统服务价值。各项生态系统服务功能除与农田相关的食物生产在增加,其余也均呈减少趋势。(4)不同地区单位面积生态系统服务价值损失量也不相同,湿地、林地面积比重下降幅度大、且农田面积比重上升幅度大的区域,其单位面积生态系统服务价值损失量也较大。

The northern Sanjiang Plain is an important commodity grain production base, also distributed by the national nature reserves of Qixinghe wetlands, Sanjiang wetlands and Honghe wetlands, which have been included in the list of important international wetlands. In the regional economy and ecology, the stability and health of local ecosystems are closely related to food security and developmental sustainability. Thus, it is desirable to know the capacity of ecosystem services in this area. This paper used the two cities and five counties in the northern Sanjiang Plain for a case study, including Youyi County, Raohe County, Baoqing County, Fuyuan County, Fujin City, Tongjiang City, and Suibin County. Based on RS, G1S, and land use data, the ecosystem service values during 1954--2009 were calculated to reflect the temporal and spatial variations according to multiple assessment models. The results showed that （ 1 ） the area of different land use types was drastically changed ： farmland increased fastest at 1.08% per year and wetlands followed at a speed of 0. 85% per year. The forest land, grassland, built-up land, and waters changed a little, within 10%, and undeveloped land was almost unchanged. The increasing demands of population and grain production were the main driving forces. （2） The total ecosystem service value of the northern Sanjiang Plain declined from ￥ 1.19×10^11 in 1954 to ￥7.80×10^10 in 2009. Long-term land development and cultivation were the main reasons for the variation of ecosystem service values, which caused the loss of wetlands, forest and grasslands, and farmland expansion. （3） During the past 55 years, only the values of farmlands and waters were increasing. By contrast, the other land types had a decrease in ecosystem service values. The value of wetland ecosystem services was reduced the most, reaching ￥8.56×10^10, followed by woodlands at ￥4.19×10^9. The greatest increment in ecosystem service value occurred in farmland, reaching ￥ 1.96×10^9. In conclusion, of all the ecosystem service functions, only the ecosystem service values of food production exhibited a rising trend with an increase of ￥ 1.23×10^9, whereas the others were decreasing, characterized by a decrease of ￥ 2.02×10^10 in water conservation, a decrease of ￥ 2.19×10^10 in waste treatment, and a decrease in ￥2.25×10^10 of climate regulation. All in all, the ecosystem services of the northern Sanjiang Plain deteriorated seriously in 55 years and the resilience of ecosystem services should be enhanced. （4） The total ecosystem service value and per unit area ecosystem service value of all regions were both declining from 1954 to 2009. The loss of ecosystem service value per unit area in different parts was not the same. The areas with a vast decrease of wetlands and forest as well as a fast increase in farmland had a significant loss. The ecosystem service value per unit area in Tongjiang City lost most by ￥2.53×10^4 per hectare from 1954 to 2009, followed by Tongjiang City, Fujin City, Youyi County, Fuyuan County, Suibin County, Raohe County, and Baoqing County.