基于山地-绿洲-荒漠系统的生态系统服务正负价值测算——以新疆玛纳斯河流域为例

基于不同生态单元分析生态系统服务正负价值有助于全面客观地了解生态系统服务的异质性。选择典型山地-绿洲-荒漠系统(Mountain-Oasis-Desert System,MODS)下的玛纳斯河流域作为研究区,以1990年、1995年、2000年、2005年、2010年及2015年Landsat系列遥感影像为数据源,采用修正后的生态系统服务价值系数对不同生态单元下的生态系统服务正负价值进行估算。结果表明:(1)1990—2015年玛纳斯河流域土地利用/覆被变化较为显著,耕地、水域及建设用地面积呈现增加趋势,林地、草地及未利用地面积呈减少趋势,其中耕地和未利用地面积变化最为剧烈,建设用地增幅最大,林地减幅最大。(2)研究时段内,研究区正向价值远高于负向价值,且净价值小幅度增加。正向价值在经历"增加-减少-减少-增加-增加"的变化过程后呈现增加趋势,并呈现山地区绿洲区荒漠区的特征;各负向价值均表现为不同程度的增大趋势,其中温室气体排放、化肥流失及水资源消耗是流域内最为突出的负向生态系统服务,三者价值之和占比在不同时间段上均达90%以上;净价值由研究初期的8947.89×10~6元增加至末期的10409.99×10~6元,年均增加0.65%。(3)人均生态系统服务净价值呈现下降趋势,流域环境压力增大。

Evaluate the positive and negative value of ecosystem services based on Mountain-Desert-Oasis system (MODS): a case study of Manas River Basin in Xinjiang

Evaluating the positive and negative values of ecosystem services based on different ecological units is helpful for understanding the heterogeneity of ecosystem services comprehensively and objectively. In this study, we chose Manas River Basin, a typical Mountain-Desert-Oasis system (MODS), as the study area, collected 1990, 1995, 2000, 2005, 2010 and 2015 series of Landsat remote sensing images as data sources, and used the adjusted ecosystem service value coefficient of ecosystem services to estimate the positive and negative values for different ecological units. Results revealed that:(1) From 1990 to 2015, the land use/cover of Manas River Basin changed significantly. The cultivated land, water area, and construction land showed increasing trends, whereas woodland, grassland and unused land showed decreasing trends. The cultivated land and unused land changed dramatically. The construction land increased the most while the woodland decreased the most. (2) During 1990-2015, the positive value of ecosystem services in the study area was much higher than the negative value, and the net value increased slightly. The positive value showed an increasing trend after the change of "increase-decrease-decrease-increase-increase" and the characteristic of mountain area > oasis area > desert area. Each negative value showed the increasing trend in different degrees. Of which greenhouse gases emission, fertilizer loss and water resource consumption were the most prominent negative values of ecosystem services in the basin. The sum of three negative values accounted for more than 90% of the total value of different periods. The net value of ecosystem services increased from 8947.89×10⁶ yuan at the initial stage of the study to 10409.99×10⁶ yuan at the end of the study, with an average annual increase of 0.65%. (3) The net value of ecosystem services per capita showed a declining trend, indicating more environmental pressures for the Manas River Basin.