Quantitative study on cultivated land ecological compensation in the area around Beijing and Tianjin from the perspective of grain security

There is renewed research on ecological compensation of cultivated lands towards food security, a necessary requirement for the stable development of a country and society.In order to promote coordinated development and construction of integration ecological environment for Beijing City, Tianjin City and Hebei Province, a grain-security-driven model was built to simulate ecological compensation of cultivated lands in the region.The model used ecosystem services value to calculate grain budget, overload index and compensation coefficient of cultivated land.The farmland ecological compensation of each county (city) was analyzed quantitatively for the Beijing-Tianjin environs using the calibrated and validated ecological compensation model for cultivated lands.The results showed that:1) the"ecological supply"and "ecological consumption" of farm lands in the Beijing-Tianjin environs were typically similar in terms of "ectopic space" phenomenon.While"ecological consumption"of cultivated lands was mainly concentrated in farmlands in the south of Beijing and Tianjin environs, "ecological supply" was mainly concentrated in cultivated farmlands in the west of Beijing and Tianjin environs.2) The value of ecosystem services of farmlands around Beijing and Tianjin in 2014 was 4.480 5×10¹⁰ ￥, whose situation continued to worsen with a total deficit of 7.834×10⁹ ￥.3) In the area around Beijing and Tianjin, Zhangbei County, Xinglong County, Weixian County, Shangyi County, Laiyuan County, on to a total of 17 counties had surpluses, and the other counties had deficits.Luannan County was highest in payment of farmland ecological compensation (5.173×10⁷ ￥), followed by Yutian County (4.864×10⁷ ￥) and then Dongguang County (4.849×10⁷ ￥).Although Zunhua County, Luanping County and Quyang County were compensable, their ecological conditions of cultivated lands were in bare balance.4) From the point of view of food security, there were several counties requiring for farmland ecological compensation in 2014 around Beijing and Tianjin, including Zhangbei County, Weixian County, Shangyi County, Yangyuan County, Laiyuan County and Quyang County.Several counties should pay for farmland ecological compensation, they were Luannan County, Yutian County, Xianxian County, Dingzhou City and Wuqiao County.Tangxian County, Laishui County and Fengning Manzu Autonomous County neither needed nor paid farmland ecological compensation.Compared with previous studies, this study on farmland ecological compensation provided a starting point for research on compensation for farmlands around Beijing and Tianjin.The results could promote economic development, ecological protection of farmlands, and sustainably efficient utilization of farmland resources around Beijing and Tianjin.Meanwhile, the application of this method provided the theoretical reference for quantitative study of ecological compensation of farmlands in similar regions.It could provide references for determining cultivated land protection index with ecological value for other area.It was vital to conduct further research on ecological compensation mechanisms in cultivated lands.