The topographic differentiation patterns of changes in habitat quality are of great significance for the scientific formulation of environmental protection policies in mountainous areas. Here, the distribution, changing trends, and the effects of the topographic gradient on habitat quality were studied using the InVEST model, the topographic distribution index, and the Mann–Kendall test. The results showed that at p < 0.05 (Z = 1.67), the habitat quality from 2000 to 2020 showed three types of trends (significant decline, non-significant change, and significant increase), accounting for 22.2%, 41.8%, and 36% of the changes, respectively. Because of the livelihood structure of the local residents and geological disasters in high-elevation areas, this terrain was the predominant area showing a significant decline in habitat quality. Thanks to the consolidation of projects for the protection of natural forest resources, the return of farmland to forest, and the implementation of projects for protecting the natural forest, the low-lying topography was the predominant area showing a significant increase in habitat quality. The middle topographic position was the predominant area showing no significant changes in habitat quality. Based on the results of the analysis, ecological management and protection measures for high-, medium-, and low-elevation areas were suggested.

Analyzing the distribution characteristics and influencing factors of cultivated land in complex geomorphic areas is significant in evaluating the agricultural farming environment and formulating cultivated land protection measures. This study extracted cultivated land information based on multi-source remote sensing data, and analyzed the geomorphic differentiation of cultivated land distribution and climate response from 2000 to 2020 using the Gini coefficient, spatial autocorrelation analysis and geographic detector. The results show that cultivated land is mainly distributed in low-altitude hills and low-altitude small undulating mountains, and secondarily in low-altitude alluvial and proluvial plains and platforms. Moreover, from 2000 to 2020, the cultivated land in the high-altitude and high-altitude undulating mountains and medium and high-altitude undulating mountains in the Northwest Plateau of Sichuan showed an upward trend, while the cultivated land in the Sichuan Basin mainly increased from the north and south to the middle of the basin. In addition, the highest temperature has the strongest ability to explain the spatial heterogeneity of cultivated land. From the calculation results of the influence coefficient of a single climatic factor and the combined effect of multiple climatic factors, the main factors that affect the distribution of cultivated land are different in different geomorphological regions. Finally, it is proposed to formulate a long-term strategy for agricultural production to adapt to climate change in complex geomorphic areas in order to reduce the negative impact of environmental change on agricultural production.