边境-粮食-生态安全视域下耕地利用生态效率演变特征与机制——以中越边境地区为例

明晰耕地利用生态效率的驱动机理是深化土地科学前沿探索、优化粮食安全发展格局的关键基础。建构"边境-粮食-生态"安全框架,采用非期望产出的超效率SBM模型测算2000-2020年中越边境地区耕地利用生态效率,通过泰尔指数研究其演变特征和区域差异,并运用动态面板系统GMM模型揭示耕地利用生态效率的驱动机制。结果表明:(1)中越边境地区耕地利用生态效率指数总体呈现"先升-后降-再升"的变化趋势,整体处在中等效率水平,空间表现为"北高-南低"分布格局,省际差异是造成区域差异的主要原因。(2)化肥使用过量、劳动力过剩和碳排放增加是造成中越边境地区耕地投入产出要素松弛、耕地利用生态效率损失的重要因素。(3)中越边境地区耕地利用生态效率由多因子交互作用驱动,地形坡度、城镇化、边境贸易水平、财政支农水平是提高耕地利用生态效率的积极因素,水土流失率、工业化和劳均耕地规模对耕地利用生态效率具有抑制效应。中越边境地区亟需优化耕地经营投入结构,向"投入优-产出高-排放低"方向转型,构建边境粮农稳态格局,促进边境地区长足稳定高质量发展。

Evolution characteristics and mechanism of cultivated land use eco-efficiency from the triple-security perspective in China-Vietnam border area

Clarifying the driving mechanism of cultivated land use eco-efficiency is a key basis for deepening the frontier exploration of land science and optimizing the development pattern of food security. This paper constructed a triple-security framework of "border-food-ecology" and applied the super-efficiency SBM model of undesired output to measure the eco-efficiency of cultivated land use in China-Vietnam border area from 2000 to 2020. We also studied its evolution characteristics and regional differences through the Theil index and used the dynamic panel system GMM model to reveal the driving mechanism. The results showed that: (1) The cultivated land use eco-efficiency index in China-Vietnam border area generally showed a trend of "first rise, then drop, final rise", and the overall efficiency was at a medium level. The overall spatial distribution exhibited a pattern of "north high and south low", and inter-provincial differences were the main reasons for regional differences. (2) Excessive use of chemical fertilizers, labor surplus and increased carbon emissions were important factors for the slack input and output of the cultivated land and the loss of eco-efficiency. (3) The change of the cultivated land use eco-efficiency in China-Vietnam border area was driven by multi-factor interaction. Terrain slope, urbanization, border trade level and financial support for agriculture were positive factors to improve the eco-efficiency. The rate of water-soil loss, industrialization and the scale of cultivated land per labor had inhibitory effect on the eco-efficiency. China-Vietnam border area urgently needs to optimize the input structure of cultivated land management, transform to the direction of "excellent input-high output-low emission", construct border food steady pattern and promote the long-term and stable development of the border areas.