Spatiotemporal structure function coupling optimizes Taihang Mountains forest grassland ecological networks for water conservation.

Mountain ecosystems are critical hubs for regional water security, yet they are highly vulnerable to habitat fragmentation. Effective conservation requires coupling complex spatial configurations directly with essential ecosystem services. Using the Taihang mountains (2000-2020) as a case study, key forest-grassland ecological sources were identified across the region. Spatial networks were then constructed via the Minimum Cumulative Resistance model to systematically assess their water conservation capacity. The analysis revealed strong positive correlations (r > 0.6, p < 0.01) between topological indicators, specifically degree and PageRank, and water conservation. This indicates that spatial structure significantly regulates regional hydrological functions. Consequently, a differentiated Keystone-Linkage optimization strategy was proposed, prioritizing the addition of 51 strategic corridors. This enhancement delayed the network's structural collapse threshold under simulated attacks by 29.5% compared to random restoration. This framework provides a practical, transferable method for designing resilient, function-oriented ecological security patterns in complex mountain landscapes.