Unveiling Spatial Patterns of Human Footprint Pressure in Nature Reserves of Yunnan Province

Multi-source data from Yunnan Province, including population density, land use, transportation networks, navigable waterways, and nighttime lights, were integrated to generate a 90 m resolution Human Footprint Pressure (HFP) map. Harmonized data for 58 national and provincial nature reserves were compiled, and the reserves were classified into five categories—natural landscape, wetland, forest, wildlife, and geological relics—according to relevant standards. Vegetation across the province was classified into nine types—rainforest and monsoon rainforest, broad-leaved forest, coniferous forest, bamboo forest, shrubland, shrub-grassland, alpine meadow, economic forest, and aquatic vegetation—using The Vegetation of Yunnan and the Forest Management Inventory (FMI) data, and spatial overlay analysis was used to evaluate HFP intensity and distribution characteristics across reserve categories and vegetation types. The results showed that provincial HFP ranged from 0 to 52 with a mean of 9.37, while HFP within nature reserves ranged from 0 to 43 with a mean of 5.48, lower than that in non-protected areas (9.61). However, under the established disturbance grading scheme, 74.55% of the nature reserve area remained in high-pressure zones (HFP ≥ 4), which was closely related to the proportion of cultivated land (3.54%). Among reserve categories, geological relics reserves had the highest mean HFP (19.38) and wildlife reserves had the lowest (4.93). Among vegetation types, aquatic vegetation had the highest mean HFP (8.90) and coniferous forest had the lowest (3.59). Compared with the global-scale HFP dataset, the overall disturbance level within nature reserves in Yunnan was relatively low, but the proportion of highly disturbed areas inside reserves remained large. Overall, nature reserves in Yunnan reduced human disturbance to some extent, but ecological quality did not improve synchronously with increasing area coverage.