The unique Karst landforms in Southwest China led to fragile soil structures and erosion, compounded by the large-scale non-agricultural transfer of the rural labor force. This study employed a two-way fixed effects model to analyze the impact of rural labor mobility on the green utilization efficiency of cultivated land, controlling for unobservable individual and time-specific factors. Mediation analysis examined how changes in planting structure influenced this relationship, considering labor force structure heterogeneity. Results revealed a U-shaped relationship, with rural labor mobility initially causing a short-term decline in efficiency but leading to a long-term increase. The mechanism of action showed that rural labor mobility indirectly affected efficiency by altering planting structures; specifically, increased replanting frequency had a partial mediating effect (0.158), while a “grain-oriented” focus masked the effect (0.067). Additionally, an aging workforce and low education levels negatively impacted green utilization efficiency, complicating the situation in the Karst region. To enhance green utilization of cultivated land, it is essential to protect migrant farmers’ rights, improve agricultural labor quality, promote industrial upgrades, and adjust planting structures. These strategies will guide regional agriculture and ensure sustainable land resource use.

Since the goals of carbon peaking and carbon neutrality have been established, forest carbon sinks have garnered significant attention. As a fundamental component of forest carbon sinks, the quality of forest land significantly influences the carbon sink capacity of forests. This study utilized Kaizhou District, Chongqing City, a typical forest area as a case study, and used the correction method, factor method, CASA model, landscape ecology indexes, and canonical correlation analysis to evaluate the level of forest land quality and reveal the spatial distribution pattern and influencing mechanisms of forest land quality. The results showed that: (i) The quality index of public welfare forest land was distributed in [37.89, 148.15], and each quality level was diversified in space. The quality index of commodity forest land was distributed in [40.00, 92.67], and some high-quality forest land appeared in the transition zone of each region; (ii) The forest land quality index and the amount of net primary productivity passed the correlation test. Primary net productivity was higher on forest land with a high-quality index and lower on forest area with a low-quality index; (iii) public welfare forest land was mainly positively affected by community structure, average annual precipitation, average annual temperature, and soil moisture. Commodity forest land was mainly positively affected by average annual temperature, soil moisture, and slope aspect. However, landform had a significant negative impact on the two types of forest land. Given these findings, we also proposed a series of measures aimed at promoting the sustainable development of research on regional forest land.

Exploring the impact of cultivated land transfer on grain green total factor productivity is of great significance in promoting efficient and low-carbon utilization of arable land and green and high-quality development of grain production in China. Based on the panel data of 30 provincial-level administrative regions in China from 2006 to 2022, this study employed the EBM model, Tobit model and mediation effect model to measure grain green total factor productivity across provinces, analyze its spatiotemporal evolution trends, and explore the influence and mechanisms of cultivated land transfer on the grain green total factor productivity. The findings revealed that: (i) The overall level of China’s grain green total factor productivity was relatively low, though it exhibited some improvement and regional differences during the sample period, with the highest level in grain-producing areas, followed by production-marketing balance areas, and the lowest level in grain-marketing areas. (ii) Cultivated land transfer had a significant positive impact on grain green total factor productivity. However, an excessively large scale of transferred cultivated land may also inhibit efficiency improvements. (iii) The impact of cultivated land transfer on grain green total factor productivity showed notable regional heterogeneity. In terms of coefficient magnitude, the impact was greater in production-marketing balance areas than in grain-producing areas, while it was not significant in major grain-marketing areas. The effect was stronger in the western region compared to the eastern and central regions. (iv) Cultivated land transfer could improve grain green total factor productivity through large-scale management of cultivated land, large-scale management of services and green production technology. Further analysis indicated a synergistic interaction between scale management and technological progress in green production within these pathways. To enhance grain green total factor productivity, it is essential to implement region-specific policies for cultivated land transfer and scale operations that account for local geographical and agricultural conditions. Specifically, policymakers should facilitate the integration of land scale management with service scale operation, while simultaneously promoting the coordinated advancement of scale operation and green production technology.