Explanatory power of phylogeny and climate to cell traits
Phylogeny alone could explain 12.5~50.5% variance of tracheid structure. The total variance explained by the best models with climatic variables as a function of traits ranged from 24.7% to 49.2%. The best models for different traits varied in their climatic variables. MAT, MAP, and their interaction were included; however, aridity index (MAI) was excluded from all multivariate models (Table 2). Taken together, phylogeny, MAT, and MAP all played a role in shaping the xylem structure.