Multidimensional Zoogeographic regionalization of terrestrial vertebrates in China: decoupling the roles of historical process and contemporary ecological filtering.

Biogeographic regionalization is fundamental for comprehending biodiversity patterns, yet the mechanisms driving the congruence or discordance between evolutionary history and ecological function remain debated. Here, we present a novel phylogenetic regionalization of China's terrestrial vertebrates and, focusing specifically on endotherms, we explore the coupling and decoupling between phylogenetic and functional regionalization by integrating functional traits within a multidimensional framework. Using variation partitioning analysis (VPA), we explicitly quantified the relative roles of deep-time geological history and contemporary ecological filtering. Our results delineate China into 11 distinct phylogenetic regions, corroborating the North-South divergence as a fundamental macro-pattern consistent with deep-time history; however, the internal structuring of these realms is significantly reconfigured compared with previous studies. Notably, Southeastern Xizang is identified as a highly distinct phylogenetic unit diverging at the deepest nodes of the tree. Furthermore, functional regionalization reveals taxon-specific assembly mechanisms. For dispersal-limited mammals, topography appears to act primarily as a historical barrier promoting vicariance and preserving deep lineage divergence. Conversely, for high-vagility birds, historical topography functions as a contemporary environmental filter, leading to an amplified functional response and convergence that outweighs phylogenetic signals. In conclusion, we reveal a hierarchical biogeographic pattern: the North-South divergence reflects ancient geological legacies associated with deep nodes, while the East-West division is largely shaped by recent Pleistocene isolation and contemporary environmental constraints at shallow nodes. This research elucidates the synergistic and decoupled roles of historical evolutionary processes and contemporary ecological forces in structuring China's zoogeographic patterns, providing a more robust scientific basis for national biodiversity conservation planning.