Analysis of ecological service value of ecological land of Bashang area based on ecological factor division

As a vital ecological barrier and biodiversity conservation base of the Beijing-Tianjin-Hebei Region, Bashang area plays an irreplaceable role in guaranteeing ecological security and water resources supply. In this study, the ARCGIS 10.2 software was used to zone the typical regions of land ecological elements through overlapping the two major ecological elements-soil and topography in Bashang area. For further research, an ecological land classification system was constructed through the combination of current land use classification system and ecosystem services function. On this basis, the equivalent factor method was used to estimate the values of ecosystem services of ecological lands in various regions of Bashang for 2015 and then the location revised based on unit area grain yield. The research aim at providing theoretical basis for the planning of ecological land use and the formulation of regional ecological protection and management policies in Bashang area. The results showed that:1) the general trend in grain yield in the Bashang area gradually increased from the central region into the two projecting wings. Both the regions of low and middle mountains of eroded cinnamon soil in the southeast of the study area were high-yield regions with yields of above 5 000 kg·hm^-2. Then low-yield areas included the region of chestnut soil basalt planform in Zhangbei County and the region of middle mountain eroded skeleton soil in Shangyi County, with yield less than 2 500 kg·hm^-2. 2) Grassland and woodland were the main types of ecological land in Bashang, accounting for 73.95% of the total area. The ecological land areas of regions of middle mountain of eroded marshy soil, alluvial aeolian plateau of marsh soil, middle mountain of eroded gray forest soil, alluvial aeolian plateau of gray forest soil accounted for over 95% of the various type areas. On the contrary, the proportion of ecological land of saline soil lake plateau region was smallest, accounting for only 39.74%. 3) The total value of ecological services in Bashang reached 63.48 billion ￥ in 2015. The maximum ecosystem service value was in the region of middle mountain of eroded brown soil in the eastern part of the Bashang area, which was mainly provided by the woodland. The ecosystem service value in the saline soil lake plateau region in the northwestern part was the smallest, which was basically provided by grassland. The research reflects that both soil type and geomorphic form influenced land production capacity, thus influencing ecological service value.