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• A conceptual framework and model of microagroecosystems were constructed. • Assessed the degree of landscape ecological risk in microagroecosystems. • The human activity gravity of microagroecosystems shifted to lower altitudes. • The ecological vitality of microagroecosystems is increasing. • Clarified micro-spatial human-land relations and development directions. Micro-spatial agroecosystem (AES) changes in karst mountain areas are a response to the human-land relationship of the human activity center. However, the changes and linkages between AESs and landscape ecological risks (LER) from a micro perspective in karst mountain areas (KMA) have not yet attracted in-depth attention from the academic community. This paper proposes the concept of microagroecosystems (MAESs) and constructs the MAES model based on the landscape development intensity (LDI) to evaluate the systematic landscape evolution rules and the LER intensity, which reflects the human-land relationship in KMA. We used the buffer ring with a 200 m cultivation range interval to categorize the MAES model into six models, namely, High-Mid-Low, High-Low-Medium, Medium-High-Low, Medium-Low-High, Medium-High-High, Low-Medium-High and Low-Medium-High, and the different models not only reflect the regional conditions but also represent the different stages of the evolution of AESs in KMAs. We found that AESs in karst mountainous areas are transforming from traditional food crop systems to economic fruit forest ecosystems, and at the same time, the gravity center of human activities is migrating from high to low altitude areas, and the ecological vitality of MAESs is showing a trend of enhancement. In addition, the regions with high altitudes and steep slopes in karst mountainous areas have a single landscape structure and are dominated by traditional food cultivation, while the regions with low altitudes and gentle slopes have a diverse landscape structure and are dominated by modern and sustainable agricultural development. Finally, we reveal that the LER in KMAs shows a trend of initial increase followed by subsequent decrease, the influence of the human-land relationship on the LER in the micro perspective is significant, and the coordination and trade-off between agricultural development and environmental protection is the key direction of development in the future. The study results can provide a reference for the rational allocation of landscape, ecological environment restoration, and optimization of regional human-land relationships in KMAs worldwide. [ABSTRACT FROM AUTHOR]

• Economic agglomeration (EA) was quantified based on nighttime light data. • All provinces are facing ecological overload excluding Qinghai. • A positive correlation between EA and ecological efficiency (EE) was found. As natural resources are becoming one of the factors hindering economic development, the utilization efficiency of natural resources should be improved and ecological stress should be reduced to ensure sustainable economic development. In this study, the ecological stress index and ecological efficiency were quantified using the ecological footprint model to describe the current status of sustainability and utilization efficiency of natural resources. The economic agglomeration was determined by conducting global spatial autocorrelation analysis using Defense Meteorological Program/Operational Line-Scan System (DMSP/OLS) nighttime light data. The relationship between economic agglomeration and ecological efficiency of China was then illustrated in a four-partite graph, and the results show that (1) the per-capita ecological footprints vary between the different provinces; however, the composition of the ecological footprint is similar between the provinces, and demonstrates the demand for fossil energy land is highest, while that for fishing ground is lowest. (2) All provinces are facing ecological overload, excluding Qinghai, and Shanghai, Tianjin, and Beijing are enduring the most severe ecological overload. (3) The ecological efficiency differs greatly between the different provinces of China, and the ecological efficiency values tend to decrease from the eastern coast to the inland region. (4) The economic activities in every province of China are spatially agglomerated, and the degree of agglomeration differs significantly. (5) There is a positive correlation between economic agglomeration and ecological efficiency, indicating that promoting economic agglomeration is an effective method of improving the utilization efficiency of natural resources. The relationship between economic agglomeration and ecological efficiency observed in this paper will provide a reference for optimizing the spatial distribution of economic activities and a theoretical basis for synchronizing environmental protection with economic development in China. [ABSTRACT FROM AUTHOR]