Leaf trait network structure drives the invasion success of Sonneratia apetala in Guangxi mangroves

Mangrove forests are vital blue carbon ecosystems that offer carbon sequestration, coastal protection, and biodiversity support. In China, native mangrove communities have become increasingly fragmented and are losing functional diversity due to anthropogenic disturbance. Since the 1980s, introduced Sonneratia apetala Buch.-Ham. has been widely used in restoration. Although it has established rapidly and aided early revegetation, it has spread along the southern coast and suppressed native species. The trait-based mechanisms underpinning the competitive advantage of S. apetala and the consequences for native functional diversity–remain unclear. We compared 17 leaf functional traits from five native mangrove species and introduced S. apetala , employing a functional trait network (FTN) approach to analyze the structural and variability patterns of leaf trait networks. The FTN framework visualized the relationships among traits as nodes and edges, enabling a comprehensive understanding of how multi-trait coordination drives ecological strategies. The connectivity and centralization of the S. apetala leaf trait network were higher than those of native species, forming a “centralized-efficient” strategy, in contrast to a “dispersed-cooperative” strategy of native species. The efficient resource-use system of S. apetala was based on high chlorophyll content, nitrogen concentration, and leaf shape factors, whereas native species instead maintained stability with conservative traits such as low specific leaf area. By framing species differences in terms of trait network topology, this study provides mechanistic insight into how introduced S. apetala attained competitive dominance and how that dominance could alter the ecosystem’s functional structure. Our findings have direct implications for restoration and management: practitioners should weigh the short-term revegetation benefits of S. apetala against longer-term risks to native functional diversity and consider restoration designs that promote trait diversity to safeguard ecosystem resilience. Further work should link FTN patterns to demographic performance and site-level environmental gradients to refine management guidance.