Space is the fundamental carrier for production, living, and ecological activities, and optimizing the spatial pattern is of vital importance to promote regional sustainable development. To achieve this goal, the core issues are to identify the risks of resource and environmental constraints of development and to realize the rational distribution of human living space. Based on the integration of multisource heterogeneous data, taking Yunnan Province, a typical mountainous area in China, as an example, this research proposes a multi-object suitability evaluation method based on 50 × 50 m grid data at the provincial scale. We build a spatial conflict analysis model to identify production–living–ecological space (PLES) and propose governance suggestions for different functional areas. The results show that (1) areas suitable for ecology make up the greatest proportion of Yunnan Province, but areas with living and ecological functions show obvious spatial complementarity; (2) areas suitable for production are restricted by steep slope, geological hazards and fragmented pattern; (3) areas suitable for living is rare, and they are mainly concentrated in the plains of central Yunnan; and (4) twenty-seven percent of area has potential spatial conflicts, among which 4.38% of the area is all suitable for production–living–ecological. The production–living advantage areas are concentrated in the central Yunnan UA (Urban agglomeration), which has a high spatial overlap. These results are expected to provide valuable insights to support comprehensive multifunctional spatial utilization and sustainable development in mountainous areas.

The sustainable and stable population support capacity of a country or region is of great concern. This study proposes a new method for evaluating the land carrying capacity (LCC) based on food nutrition demand and establishes a clear link between nutritional health and land. We delved into the evolving dynamics of food consumption and production structures in China between 1990 and 2020, with a focus on the spatial variations among its 31 provinces. The objectives of this study were to assess the status of LCC, identify the critical nutritional factors constraining LCC enhancement, and propose differentiated pathways for improving LCC. The results showed that: (1) There has been a steady increase in the annual consumption of animal-based products, while plant-based product consumption has declined. (2) Overall, food supply capacity has expanded, displaying an “east high, west low” trend, resulting in an imbalanced food supply level. (3) The LCC for energy and carbohydrates exhibited continuous fluctuating growth but displayed a declining trend after 2018. (4) The pressure on land carrying capacity has shifted from a state of “surplus” to “abundant surplus,” signifying a safe food system level. However, significant spatial variations persist, leading to shortages and surpluses. Therefore, this work suggests that addressing these disparities requires the optimization of food consumption structures and increasing the supply of animal-based foods. This approach leverages regional advantages and reduces disparities in regional LCCs. This study provides a valuable reference for ensuring food security in response to unprecedented global changes in sustainable development.

Climate change and socio-economic transformation increasingly challenge the stability of China’s food supply. This study aims to optimize grain crop layouts by integrating natural suitability and nutritional supply within a unified analytical framework. Using the MaxEnt model incorporating bioclimatic, topographic, and soil variables, we simulated the natural suitability of major grain crops and compared it with actual planting patterns based on the SPAM dataset. Results revealed substantial spatial discrepancies between actual and suitable distributions, with national planting diversity index increasing by 26.42% (from 0.53 to 0.67) under suitable conditions. Wheat and maize are most suited to northern China, rice and tuber crops to southern regions, while soybean performs optimally in the northeast. Nutrient supply potential also improved substantially under the suitable scenario, with energy, protein, fat, and carbohydrate increasing by 56.9 × 10⁸ KJ, 77.2 × 10⁶ g, 23.3 × 10⁶ g, and 48.6 × 10⁶ g per million people, respectively. Among alternative structures, maize-soybean and maize-based planting structures better aligned with both natural adaptability and nutritional balance (e.g., in Inner Mongolia and Heilongjiang), whereas rice-based structure showed weaker correspondence (e.g., in Shanghai). These findings demonstrate that naturally adaptive optimization can enhance both environmental compatibility and nutritional adequacy, providing scientific guidance for developing climate-resilient and nutrition-oriented crop layout strategies in China.

Yunnan Province, which is located in the mountainous plateau region of China, faces numerous challenges, including the population decline of rural areas. Achieving coordinated development between the transportation and rural population systems is crucial for fostering sustainable growth. In this study, we developed a rural population pressure state response (PPSR) model and a comprehensive transport superiority (TS) model that considers the influence of aviation. We quantified the rural population system and horizontal transportation superiority across Yunnan’s districts and counties for the period 2013 to 2021, examining their temporal and spatial heterogeneity. Using a spatial autocorrelation model, we also explored the trade-offs and synergy between Yunnan’s TS and PPSR. The main findings are as follows. (1) From 2013 to 2021, the spatial polarization pattern of PPSR in Yunnan Province gradually weakened, and there were different degrees of rural contraction overall. (2) From 2013 to 2021, Yunnan’s TS significantly increased, with aviation conditions having a notably positive impact, further strengthening Kunming’s position as the regional core. (3) In Yunnan, the relationship between TS and PPSR is significant, with a collaborative pattern emerging across districts and counties, reflecting distinct regional characteristics and a degree of polarization. This study provides valuable insights for integrating urban and rural development in plateau and mountainous areas and offers a new perspective for rural revitalization.

Plateau lake regions face escalating conflicts between food production and ecosystem conservation under rapid urbanization and strict ecological regulation. However, existing evaluations often overlook the positive ecosystem services generated by cultivated land and fail to capture the nonlinear mechanisms shaping eco-efficiency of cultivated land use (ECLU). This study develops an ecosystem service-based framework to assess the ECLU of Kunming, a typical plateau lake-basin city in southwest China, from 2005 to 2022. Ecosystem service value (ESV) is incorporated as a desirable output within a super-efficiency SBM model, and an XGBoost–SHAP approach is applied to identify the intensity, nonlinear thresholds and interaction mechanisms. Results show an average ECLU of 1.12 with a fluctuating downward trend and widening spatial disparities. High-efficiency zones cluster in central–southern regions, while urbanizing cores experience ecological function degradation despite productivity gains. Cultivated land fragmentation is the dominant barrier, with a critical threshold of 31.90 mu, and fertilizer intensity turns detrimental beyond 0.19 t/ha. Urbanization exhibits an inverted-U pattern—initially suppressive (55%)—with the promotion phase weakened by approximately 67% under severe fragmentation. Globally, threshold-based zoning and fragmentation mitigation must precede fertilizer optimization to ensure synergistic benefits.