Habitat connectivity evolution and management strategies under the dual drivers of urban expansion and renewal: A case study of nanning, China

With accelerated urbanization, both urban expansion and renewal have significantly affected habitat connectivity and stability. Focusing on Nanning's main urban area, this study used landscape pattern and complex network methods to evaluate habitat connectivity under different urban development scenarios. Results show that urban expansion—mainly converting unused suburban land into construction land—fragmented large habitat patches. Although ecological corridors increased by 211, overall connectivity decreased by 1 %, and potential connectivity declined by 16 %, considerably weakening ecosystem stability. In contrast, urban renewal—redeveloping old residential areas—added 7.21 km 2 of green space and 213 ecological corridors, increasing overall connectivity by 1 % and potential connectivity by 18 %. This effectively offset connectivity loss from expansion, though compensation was unequal: approximately 2 units of renewed area were needed to counteract 1 unit of expanded area. The study identified 49 key ecological priority areas totaling 55.18 km 2 , whose degradation would severely impact the regional ecological network. Under combined expansion and renewal, the ecological network showed "overall weakening but local enhancement" in topology, with improved local robustness but reduced overall stability. Scientifically identifying and hierarchically managing priority conservation and restoration areas are crucial for enhancing urban ecosystem stability and services. These findings offer insights for ecological space optimization and spatial planning in Nanning and other fast-urbanizing regions. • Urban expansion weakens habitat connectivity; renewal enhances it via green corridors. • Expansion causes fragmentation; renewal boosts network stability with green spaces. • Identifies 49 key ecological zones for protection and restoration strategies. • Reveals synergies/trade-offs between expansion/renewal for ecosystem management.