西北地区地域辽阔,地理位置得天独厚,动物区系特殊而丰富,但生态系统脆弱,容易受到环境变化的影响,严重影响物种数量和生境状况。论文以卫星遥感及地面物种调查数据为主要数据源,以地球生命力指数（Living planet index,LPI）分析生物多样性水平和变化趋势,表征物种变化状况;将土地利用数据重分类为6种生态系统类型,将森林、草地、荒漠、水体和湿地生态系统定义为自然生境,聚落和农田生态系统定义为人工生境,其面积大小表征物种栖息地状况。对1980—2015年脊椎动物种群数量及生境状况变化趋势进行综合分析,结果表明：西北地区脊椎动物种群数量自1980年以来整体呈下降趋势,至2013年下降了57.83%,但2005年后呈逐渐恢复的趋势;青海湖裸鲤（Gymnocypris przewalskii）、普氏原羚（Procapra przewalskii）和朱鹮（Nipponia nippon）等物种数量分别增加55.77%,26.03%和304%,2000年之前处于下降趋势,2000年之后显著增加,但野骆驼（Camelus ferus）、四爪陆龟（Testudo horsfieldii）等物种的种群数量呈指数型下降,且下降趋势仍未缓解;草地、荒漠生态系统面积减少,森林、水体和湿地生态系统面积增加,整体上主要由自然生境转为人工生境。本文对了解研究区动物及其环境变化、生态环境保护具有重要意义,根据研究结果制定控制物种数量的措施以及对物种数量变动预测都发挥很大作用,同时也有利于西北地区生物多样性保护的研究和管理。

The northwestern region of China has a vast territory, a unique geographical location, and a special and rich fauna. However, its ecosystem is fragile and vulnerable to environmental changes. This region is facing the dual pressure of climate and human activities, which critically affects the number of species and habitat conditions. Therefore, this article uses satellite remote sensing and ground-based species survey data as the main data source. Living planet index is used to analyze the level and the change trend of biodiversity and characterize the change status of species. Land use data were reclassified into six ecosystem types. Forest, grassland, desert, water, and wetland ecosystems were defined as natural habitats, and settlement and farmland ecosystems were defined as artificial habitats. Their area represented the habitat status of species. A comprehensive analysis of the change trend of the vertebrate population and habitat status since 1980—2015. The results showed that the vertebrate population in northwest China had a downward trend since 1980 and decreased by 57.83% in 2013, but it gradually recovered after 2005. The number of Gymnocypris przewalskii, Procapra przewalskii, and Nipponia nippon in Qinghai Lake increased by 55.77%, 26.03%, and 304%, respectively. This number exhibited a downward trend before 2000 and increased significantly after 2000, but the population number of Camelus ferus, Testudo horsfieldii, and other species decreased exponentially, and the downward trend has not been alleviated. The area of grassland and desert ecosystem decreased, and the area of forest, water body, and wetland ecosystem increased. On the whole, it has mainly changed from natural habitat to artificial habitat. The research is of great significance to understand the animals and their environmental changes and eco-environmental protection in the study area. Such an analysis plays a major role in formulating measures to control the number of species and predicting the change of species according to the research results. It is also conducive to the research and the management of biodiversity conservation in northwest China.