Spatial patterns of wood traits in China are controlled by phylogeny and the environment

Aim Wood properties are related to tree physiology and mechanical stability and are influenced by both phylogeny and the environment. However, it remains unclear to what extent geographical gradients in wood traits are shaped by either phylogeny or the environment. Here we aimed to disentangle the influences of phylogeny and the environment on spatial trends in wood traits. Location China. Methods We compiled a data set of 11 wood properties for 618 tree species from 98 sampling sites in China to assess their phylogenetic and spatial patterns, and to determine how many of the spatial patterns in wood properties are attributable to the environment after correction for phylogenetic influences. Result All wood traits examined exhibited significant phylogenetic signal. The widest divergence in wood traits was observed between gymnosperms and angiosperms, Rosids and Asterids, Magnoiliids and Eudicots, and in Lamiales. For most wood traits, the majority of trait variation was observed at genus and species levels. The mechanical properties of wood showed correlated evolution with wood density. Most of the mechanical properties of wood exhibited significant latitudinal variation but limited or no altitudinal variation, and were positively correlated with mean annual precipitation based on both Pearson's correlation analysis and the phylogenetic comparative method. Correlations at family level between mean annual temperature and wood density, compression strength, cross-section hardness, modulus of elasticity and volumetric shrinkage coefficient became significant after correction for phylogenetic influences. Main conclusions Phylogeny interacted with the environment in shaping the spatial patterns of wood traits of trees across China because most wood properties showed strong phylogenetic conservatism and thus affected environmental tolerances and distributions of tree species. Mean annual precipitation was a key environmental factor explaining the spatial patterns of wood traits. Our study provides valuable insights into the geographical patterns in productivity, distribution and ecological strategy of trees linking to wood traits.