Temporal and spatial variation and driving factors of farmland ecological service value in Chongqing

Farmland plays an irreplaceable role in ensuring the supply of materials and of ecosystem services. In this study, we aimed to explore the regional farmland ecological service value in terms of spatial and temporal changes as well as driving factors, based on the statistical yearbook of Chongqing from 2007 to 2016 and the counterpart annual data of the districts and counties in Chongqing in the relevant years. We constructed a farmland ecological service value index system, evaluated the farmland ecological service value in Chongqing based on the price index and tabulation and list method, and analyzed the social driving factors contributing to the difference in per capita farmland ecological service value among districts and counties in Chongqing using the STIRPAT model. The results showed that the values of farmland ecological services in Chongqing in 2007, 2012 and 2016 were ￥89.80 billion, ￥93.89 billion and ￥103.84 billion, respectively. The farmland ecological service value showed an evident upward trend with an increase rate of 15.63%. The 10-year mean farmland positive service value (￥102.45 billion) was considerably higher than its negative value (￥5.90 billion). In terms of the temporal change of farmland ecological services value, the total amount and per capita difference in the west of Chongqing were the most significant (30.32% and 16.80%, respectively). In the west of Chongqing, the farmland negative value of the Yongchuan and Jiangjin Districts, where agriculture is more developed, was relatively prominent. The farmland ecological service value ranked as follows:southeast of Chongqing (￥5 855 per person) > northeast of Chongqing (￥4 027 per person) > west of Chongqing (￥3 846 per person) > center of Chongqing (￥40 per person). The agricultural population, urbanization rate and energy consumption per ￥10 000 of GDP were the social driving factors attributable for the spatial difference of the per capita farmland ecological service value in all districts and counties of Chongqing. Development of the main city area had exerted a substantial pressure on its farmland ecosystem. The industry structure in this area should be rationally adjusted to improve the farmland ecological service value. The research results provide a scientific basis for the ecological environment protection, restoration, and compensation of farmland in Chongqing.