鄂尔多斯市生态系统格局和质量变化及驱动力

生态系统变化是生态问题产生的主要驱动力之一,研究生态系统格局与质量变化对于认识人类活动与生态系统关系具有重要意义。鄂尔多斯市能源资源丰富,但生态环境脆弱,2000年以来,鄂尔多斯市在大规模开发能源的同时,也在不断加强生态环境的保护,而研究鄂尔多斯市生态系统格局与质量演变过程,对认识生态脆弱区发展与保护的关系有重要价值。应用遥感数据和GIS技术,评估了鄂尔多斯市生态系统类型与格局、生态系统质量的特征,以及2000年以来的时空变化趋势,分析了导致鄂尔多斯市生态系统格局与质量变化的驱动力因素。结果表明:(1)鄂尔多斯市的草地、荒漠裸地和农田为主要生态系统类型,分别占2010年市域面积的64.46%、21.34%与5.93%。(2)鄂尔多斯市城镇、灌丛、森林面积有所增加,草地、湿地、农田、荒漠裸地面积有所下降。城镇面积增幅最大,相对变化率增加33.37%,草地面积降幅最大,相对变化率减少0.78%,变化主要集中在中部、东北部。(3)鄂尔多斯市生态系统质量整体偏低,低等级与差等级的生态系统面积比例高达98.91%。全市的生态系统质量没有明显改善,其中生态系统质量有不同程度改善的面积为15.84%,质量降低的面积比例为15.29%。(4)生态系统格局与质量变化的主要驱动力有城市扩张、农田开垦、退耕还林(草湿)、生态保护、矿山开采等,鄂尔多斯市生态系统质量与降水、退耕还草工程、道路密度、温度、GDP1、放牧因子相关性显著。

Analysis of driving factors that influence the pattern and quality of the ecosystem in Ordos

Ecosystem change is one of the main driving forces of ecological problems. Studies on ecosystem pattern and quality change have great significance in understanding the relationship between human activities and the ecosystem. Ordos has plenty of energy resources, but its ecological environment is fragile. Since 2000, simultaneously with extensive energy exploration, protection of the ecological environment in Ordos has also been strengthened. Therefore, it is important to study the relationship between the pattern and evolutionary quality of Ordos''s ecosystem to understand the relationship between the development and protection of ecologically fragile areas. In this study, remote sensing data and GIS technology were used to evaluate the characteristics and pattern of the ecosystem in Ordos, and to analyze the characteristics of ecosystem quality, trend of spatio-temporal changes from 2000 to 2010 in the ecosystem, and factors determining the pattern and quality of the ecosystem.We obtained the following results:(1) The ecosystem in Ordos can be divided into seven types:forest, shrub, grassland, wetland, farmland, urban and deserted and bare lands. Grasslands, deserted and bare lands, and farmlands accounted for 64.46%, 21.34%, and 5.93%, respectively, of the city area in Ordos in 2010. (2) The areas of urban, shrub and forest lands increased during the study period, while those of grassland, wetland, farmland, and deserted and bare lands decreased. The increase in the area of the urban lands was the highest (33.37%). Simultaneously, the decrease in the area of the grasslands was the highest (0.78%). In the middle of Ordos city, the landscape pattern at the northeastern part changed to the greatest extent. It mainly concentrated in the central and northeastern of Ordos, which changed the most. (3) The quality of the Ordos ecosystem was low; 98.91% of its ecosystems were of low grade or poor grade. Furthermore, the overall ecosystem quality showed no significant improvement during the study period; quality improved in 15.84% of the area and declined in 15.29% of the area. (4) The main driving forces of the ecosystem structure and quality change in Ordos are urban expansion, farmland reclamation, converting farmland to forest (or to grass-or wetland), ecological protection, and mining. The correlations between the quality of the ecosystem and precipitation, converting farmland to grassland, road density, temperature, GDP1, and grazing factors were significant.