Afforestation Partially Offsets Losses of Soil Conservation Services and Carbon Stock From Direct and Indirect Urban Expansion in China

Urban expansion has exerted both direct and indirect impacts on natural land and ecosystem services it supports, driven by increasing population and food demand, yet these underlying pathways remain insufficiently distinguished. Here, we quantified the losses of soil conservation services (water erosion regulation and sandstorm prevention) and carbon stock in China from 2000 to 2020, resulting from direct and indirect urban expansion. Direct land cover changes induced by urban expansion (DUE) denotes the conversion of natural land and cropland into urban areas, while Indirect land cover changes induced by urban expansion (IUE) entails cropland occupying natural lands to compensate for urban‐induced cropland loss elsewhere. Explicit impacts of IUE (EIUE), involving cropland expansion onto natural land under the Farmland Requisition‐Compensation Balance (FRCB) Policy; and implicit impacts of IUE (IIUE), driven by natural land losses through non‐FRCB‐driven cropland expansion. Results demonstrated that IUE induced 37.77 Mha natural lands loss, which was 15‐times as that from DUE. DUE and EIUE concentrated in eastern China, while IIUE concentrated in central, western and northeastern. Furthermore, IUE caused greater losses than DUE regarding carbon stock (94.31 vs. 4.48 Mt C), water erosion regulation (5353.01 vs. 205.31 Mt), and sandstorm prevention (49.48 vs. 1.48 Mt). Afforestation partially offsets negative impact of DUE and IUE, with stronger effects observed in northeastern and southern China. However, its effect on sandstorm prevention was limited due to spatial discrepancies between afforestation hotspots and major wind erosion areas. This research provides an insightful understanding on multi‐dimensional impacts of urban expansion on land cover and ecosystem services to inform more sustainable land‐use strategies.