青藏高原地区生态资产核算研究——以西藏自治区山南市为例

生态资产是重要的自然资源资产，也是优质生态产品提供的基础，生态资产的变化趋势可作为衡量生态保护和恢复成效的重要指标。山南市拥有青藏高原地区各种生态资产类型，以山南市为例开展生态资产核算可为青藏高原地区生态资产评估与保护提供参考。以生态资产数量、质量和生态资产指数为主要指标，揭示山南市2000-2015年生态资产的变化趋势及影响因素。结果表明：（1）2015年山南市生态资产以草地和森林为主，分别占生态资产总面积的40.6%和35.8%；但质量不高，优、良等级比例仅占11.8%和12.0%；生态资产综合指数为38.26，草地、森林、灌丛和湿地生态资产指数分别为16.23、14.88、5.37和1.78；（2）2000-2015年，山南市生态资产面积总体变化不大，森林和荒漠生态资产分别增加50.2 km²和43.9 km²，但湿地、农田、草地、灌丛、冰川生态资产面积分别减少97.4、29.8、2.9、2.7、0.3 km²；生态资产质量明显提升，优级和良级生态资产增幅分别为40.5%和108.5%；生态资产指数增加了16.1%；（3）退耕还林还草等生态保护和修复政策、城镇扩张以及气候变化等是山南市生态资产变化的主要因素。

Assessment of ecosystem assets in Qinghai-Tibet Plateau: a case study of Shannan City

Ecosystem assets are important natural resource assets and the basis of high-quality ecological products provisioning. The change trend of ecosystem assets can be used as an important indicator to measure the effectiveness of ecological protection and restoration. Shannan City has various types of ecosystem assets on the Qinghai-Tibet Plateau. Taking Shannan City as an example to carry out ecosystem assets accounting can provide reference for the evaluation and protection of ecosystem assets in the Qinghai-Tibet Plateau. Based on the area and quality of ecosystem assets and the ecosystem assets index as the main indicators, this study reveals the changing trend and influencing factors of ecosystem assets in Shannan City from 2000 to 2015. The results show that: 1) In 2015, grassland and forest were main ecological assets of Shannan City, accounting for 40.6% and 35.8% of the total ecosystem assets, respectively. The quality of ecosystem assets in Shannan City is low, and the proportions of excellent and good grades are 11.8% and 12.0%, respectively. The index of ecosystem assets in Shannan City is 38.26, and the indexes of grassland, forest, shrub, and wetland are 16.23, 14.88, 5.27, and 1.78, respectively. 2) During 2000 to 2015, the area of ecosystem assets in Shannan City had little change. Forests and desert ecosystem assets increased by 50.2 km² and 43.9 km², respectively, while the area of wetlands, farmland, grassland, shrubs, and glaciers decreased by 97.4 km², 29.8 km², 2.9 km², 2.7 km² and 0.3 km², respectively. The quality of ecosystem assets was significantly improved, with the growth rates of excellent and good grade ecosystem assets being 40.5% and 108.5%, respectively. The ecosystem assets index of Shannan City increased by 16.1%. 3) The changes of ecosystem assets in Shannan City are mainly affected by such factors as sloping land conversion program and other ecological protection and restoration policies, urban expansion and climate change.