天山北坡经济带关键性生态空间评价

关键性生态空间在生态系统中所发挥的基础性和保障性功能尤为重要,其范围辨识及评价研究对于国土安全和区域可持续发展具有重要意义。以天山北坡经济带为研究区,构建适于西北寒旱区脆弱敏感环境的关键性生态空间评价体系,借助GIS和RS技术,从生态系统服务功能重要性和敏感性两方面对其空间范围进行辨识和分级评价,并进行土地利用生态安全冲突分析。研究结果表明:(1)底线型和危机型生态空间作为研究区的关键性生态空间,面积为45318km²,占比53%,主要分布于南部山区、农垦区西部及北部沙漠/荒漠区;(2)生态系统服务功能与植被显著相关,较重要、重要和极重要区域共占约20.9%,集中在南部山前草原及中部农垦区,生态系统服务功能整体较弱,主导因子为水源涵养和生物多样性保护功能;(3)研究区生态系统敏感性等级主要以中度敏感为主,敏感和极敏感区域面积占比37.7%,分布于高山区、荒漠戈壁区和低山与绿洲过渡区,主要体现为土地沙化和土地盐渍化。(4)全区土地利用生态安全冲突等级较高,有45%的城建用地与56.5%的耕地占用关键性生态空间。本研究可为区域国土空间布局和生态格局优化提供参考,并对相关理论和实证研究起到补充和借鉴作用。

Evaluation on the critical ecological space of the economic belt of Tianshan northslope

The basic and supporting functions of critical ecological space in the ecosystem are particularly important. It is of great significance for homeland security and regional sustainable development to identify and evaluate the scope of the critical ecological space. Taking the economic belt of Tianshan northslope as the research area, we constructed a critical ecological spatial evaluation system suitable for the fragile and sensitive environment in the northwest cold and dry area. With the help of GIS and RS, the spatial scope of the critical ecological space was identified and graded from the importance and sensitivity of the ecosystem service function, then analyzed the conflict of land use ecological security. The results showed that: (1) The critical ecological space generally consists of the bottom line type and crisis type ecological space with area 45318 km², accounting for 53% of the total area, mainly distributed in mountainous, desert and the northwest of the agricultural reclamation area. (2) The ecosystem service function is significantly related to vegetation. The medium important, important and extremely important areas account for about 20.9%, which are concentrated in the southern piedmont grassland and the central agricultural reclamation region. The ecosystem service function are weak as a whole, and the dominant factors are water conservation and biodiversity conservation function. (3) The primary sensitivity level of the study area is medium sensitive. The sensitive and extremely sensitive areas account for about 37.7%, which are distributed in high mountain area, gobi desert terrain and the transition area between low mountain and oasis, principally reflected in desertification and salinization. (4) The conflict level of land use ecological security in this region is relatively high, there are urban construction land 45% and cultivated land 56.5%occupy the critical ecological space. This study can provide reference for the optimization of regional land spatial distribution and ecological pattern, and play a complementary and referential role for the relevant theoretical and empirical research.