| Food security has always been the focus of the government and scholars both in China and abroad.At different stages,the content and characteristics of food security are different.With the tightening of resources and environmental constraints,how to speed up the transformation of agricultural development,how to ensure the effective supply of important agricultural products such as grain,and how to achieve green development and sustainable use of resources to ensure the sustainable food security have become an important policy focus of our government.In this context,the paper comprehensively clarifies the theoretical connotation of sustainable food security under the ecological perspective,reasonably evaluates the realistic situation of sustainable food security under the ecological perspective,and analyzes the influencing factors and international experience of sustainable food security from the ecological perspective.Food security policy is important to protect the stable socio-economic development of China.First of all,through the analysis of relevant literatures in China and abroad,this paper explains the theoretical connotation of sustainable food security from the perspective of input,production,supply,acquisition and utilization.Then,based on the sustainable use of time limit perspective,this paper deduces the theoretical mechanism of sustainable food security from the perspective of input supply,food consumption and food demand.Sustainable food security means that at all times the people of a country(or region)have the material and economic conditions required to obtain adequate,safe and nutritious food to meet the dietary needs and food preferences,and these conditions are intertemporally available.From the ecological perspective,sustainable food security is more emphasized that in all aspects the food input,production,supply,access and use should be in harmony with the ecological environment,that is,food security is not at the expense of ecological damage.In the aspect of input,ecological sustainable food security is reflected in the input and supply of cultivated land resources,water resources,labor force,technology and institutional arrangement.In the aspect of production,ecological sustainable food security is mainly faced with pollution from production and energy consumption.In the supply chain,ecological food sustainable security should consider four aspects:a relatively balanced supply,foreign food dependence,supply of social constraints and supply of natural constraints.In the link chain,ecological food sustainable security is mainly embodied in the spatial scheduling ability of food,the relative purchasing ability,the economic profitability and the food accessing ability under the small-peasant economic system.In the aspect of using chain,the ecological sustainable food security pays attention to the ecology of food processing and utilization,avoiding food pollution and reducing food wastage rate.Secondly,this paper constructs the index evaluation system of sustainable food security in China under the ecological perspective,and it uses the entropy method to evaluate the sustainable food security of China under the ecological perspective.This paper also quantitatively analyzes the current situation,trend and existing problems of sustainable food security.In this paper,based on 342 prefecture-level administrative regions,the spatial pattern of cultivated land pressure in China from 2001 to 2013 was analyzed by using the cultivated land pressure index,GDI index,spatial autocorrelation and average growth index.It can reflect China’s land resources constraints for sustainable food security.In view of the macroeconomic situation,the situation of sustainable food security has made progress in China’s ecological perspective from 1997 to 2014 and shows a significant stage.But there also exists some problems that can not be ignored:cultivated land decreasing,food price rising,profits reducing in food processing enterprises and food safety issues highlighting.In this paper,the situation of cultivated land pressure in China has been gradually reduced since 2001,but the spatial differentiation degree has been strengthened and the spatial agglomeration trend continues.The pattern of cultivated land pressure in China is generally stable and localized,and the trend of north-south differentiation is significant.The quality of cultivated land is the basic factor to determine the pressure of cultivated land in China.The pattern of cultivated land pressure in China is generally stable and localized,and the trend of north-south differentiation is significant.The quality of cultivated land is the basic factor to determine the pressure of cultivated land in China.Based on the above analysis,this paper further selects the main factors influencing the sustainable food security in China from the aspects of input,production,supply,acquisition and utilization,then makes a theoretical analysis on the path of its impact.At the same time,the effects of main influencing factors is analyzed by using the quantile regression method and the pulse effect function on the basis of the stability test,the Johansen cointegration test and the Granger causality test.The impact of urbanization development and industrial structure adjustment on sustainable food security is "U" type.The effects of ecological environment management,agricultural labor loss,technological progress on the sustainable food security are positive.The impact of urban and rural income gap is negative.The influence of these factors shows a structural effect and a fractional effect.The structural effect of the food security shows that in the input,production,supply,access and using chains,the impacts of main factors is different.The fractional effect shows that with the improvement of sustainable food security,the effects of the main factors are different.Then,this paper summarizes international experiences in achieving sustainable food security in ecological perspective from advanced countries such as the United States,Japan,Germany and South Korea.The United States attaches importance to the ecological factors of production,ecological subsidies and food reserves,price support and food subsidies;Japan pays attention to agricultural mechanization and scale management,agricultural production subsidies and ecological technology utilization;South Korea attaches importance to land transfer and outward policy,ecological production and innovation subsidy policy,guarantee food self-sufficiency.Finally,this paper puts forward some policy suggestions on sustainable food security in China.In the input link,our country should pay attention to the protection of cultivated land resources,water resources,the sustainable allocation of rural labor force and technological progress.In the production process,our country should optimize the mode of agricultural development to enhance the carrying capacity of ecological environment,improve the layout of urban and rural functional areas to form a new pattern to save energy and reduce emission,and use the means of policy control to actively develop low-carbon agriculture.In the supply chain,we should optimize the food import and export strategy based on the ecological sustainable aspects,standardize the green food subsidy strategy,promote the natural disaster prevention and control mechanism,and design the food balance control system.In terms of access,China should enhance the economic profitability of the food market,maintain the stability of the food market,and raise the income level of the residents in the rural areas to promote the sustainable development of food.In the using chain,we should establish the food safety and security mechanisms to strengthen the food market supervision and management. |
