In recent years, irrational land development has caused significant habitat quality problems. Previous habitat quality studies have mainly concentrated on medium- and small-sized areas, and few studies have conducted a comprehensive long-term analysis of terrestrial habitat quality in large countries. Accordingly, this research aimed to identify the changes in land use and habitat quality in China during the last four decades. The InVEST method was employed for evaluating China’s habitat quality. This evaluation included both habitat degradation and habitat quality scores. Then, the FLUS and InVEST methods were combined to project future land use evolution in China through 2050 and assess its effect on habitat quality. Our study demonstrated a robust connection between habitat quality and the spatial distribution of land use classes, topography, and resource availability. Furthermore, over the past four decades, high-quality habitats in the country have been degrading and shrinking, while low-quality habitats have been expanding. The projection results indicate that the habitat problems in China will become increasingly severe over the coming decades. Our study suggests that the habitat quality in China should be improved by optimizing land use patterns, stabilizing areas with optimal habitat conditions, and restoring degraded habitats.

The Requisition–Compensation Balance of Cropland (RCBC) policy is important for ensuring food security. Previous studies have mainly focused on the quantity and quality of cropland when assessing the impacts of this policy. In terms of morphology, previous studies have primarily relied on landscape indicators. Therefore, this study aims to thoroughly analyze the impacts of the RCBC policy on the quality and morphology of cropland (especially morphological spatial pattern analysis, MSPA) in the Pearl River Delta (PRD) during 1996–2021. To this end, we constructed a comprehensive evaluation index system by combining MSPA, landscape indicators, and field research. The results show that the cropland quality in the PRD has exhibited a consistent improvement trend. High-quality cropland is spreading from central cities to the periphery, and the spatial distribution is becoming more even. Nonetheless, MSPA reveals an increasing trend of cropland fragmentation. The results indicate a decline in the area of the “core”, an increase in the area of the “island”, and a decrease in the connectivity of the cropland. Our field research confirms that the RCBC policy has indirectly exacerbated cropland fragmentation. In many regions of the PRD, the fragmentation of cropland hinders the application of agricultural mechanization and increases the cost of cultivation, resulting in severe cropland abandonment. Therefore, local governments should implement rigorous planning and prioritize cropland morphology when compensating cropland. Our findings are expected to provide empirical evidence for improving the RCBC policy and protecting cropland.