Impact of Uphill Cropland Expansion on Natural Habitats in Southwest China

ABSTRACT

The displacement of cropland expansion from restricted plains to elevated terrains jeopardizes the integrity of mountain habitats, undermining the conservation targets set by the Kunming‐Montreal Global Biodiversity Framework. However, the distinctive ecological loss of uphill cropland expansion (UCE) is frequently conflated with total cropland expansion, obscuring its unique impact on mountain biodiversity. Here, we established an assessment framework spanning “landscape pattern—habitat quality (HQ)—biodiversity function” to quantify ecological losses driven by UCE. By employing counterfactual simulations, we disentangled UCE‐driven losses from total losses to broader land‐use changes. Our results reveal that UCE prevalence peaks within the 500–1500 m altitudinal band and on terrain with slopes either < 10° or > 30°. The margins of the Sichuan Basin, southeastern Guizhou, and inter‐provincial border regions exhibit marked spatial overlap between UCE hotspots and the resulting areas of intense habitat fragmentation. At the grid scale, UCE‐driven HQ loss represents ~17% of the total in Southwest China, with direct impacts being more extensive than indirect impacts. The threatened species richness (THR) exposed to UCE approaches the local average THR. In Sichuan and Chongqing, UCE threatens more species than non‐UCE. Our findings underscore the urgent imperative for targeted ecological restoration in steep‐slope mountain habitats, offering global implications for balancing food security with biodiversity conservation in Key Biodiversity Areas.