China’s Sponge City Program unlocks potential for urban plant diversity

China's Sponge City Program (SCP), the world's largest urban green spaces (UGSs) retrofitting initiative for mitigating waterlogging and pollution, holds underappreciated potential for reconstructing plant communities. Here, we demonstrate that across 1,973 sponge city green infrastructures (SCGIs) in Wuxi, the SCP significantly enhances plant diversity (increased plant coverage, species richness, evenness, and reduced dominance), synchronizing its distribution at a high level across the catchment. We find that biodiverse designs (e.g., rain gardens [RGs], bioswales [BSs]) alongside linear project implementation are key drivers and propose a strategic network approach to maximize gains by embedding SCGIs in UGS planning, leveraging linear projects as potential corridors and employing multifunctional designs. This work reconciles stormwater management with biodiversity conservation, supporting China's commitment to the Kunming-Montreal Global Biodiversity Framework (GBF) Target 12 through improved UGS area, quality, and connectivity. These insights offer actionable pathways for subtropical/tropical Asian cities to enhance ecological resilience amidst rapid urbanization.