With the expansion of urban areas, the remnants of forested areas play a crucial role in preserving biodiversity in urban environments. This study aimed to explore the impact of spatiotemporal urban expansion on the networks of leaf traits in woody plants within remnant forest patches, thereby enhancing our understanding of plant adaptive strategies and contributing to the conservation of urban biodiversity.

Our study examined woody plants within 120 sample plots across 15 remnant forest patches in Guiyang, China. We constructed leaf trait networks (LTNs) based on 26 anatomical, structural, and compositional leaf traits and assessed the effects of the spatiotemporal dynamics of urban expansion on these LTNs.

Our results indicate that shrubs within these patches have greater average path lengths and diameters than trees. With increasing urban expansion intensity, we observed a rise in the edge density of the LTN-shrubs. Additionally, modularity within the networks of shrubs decreased as road density and urban expansion intensity increased, and increases in the average path length and average clustering coefficient for shrubs were observed with a rise in the composite terrain complexity index. Notably, patches subjected to 'leapfrog' expansion exhibited greater average patch length and diameter than those experiencing edge growth. Stomatal traits were found to have high degree centrality within these networks, signifying their substantial contribution to multiple functions. In urban remnant forests, shrubs bolster their resilience to variable environmental pressures by augmenting the complexity of their leaf trait networks.