Figure Legend
Figure 1 . Spatial distribution of the data in this study. Each
dot represents a species’ central distribution location in China, using
the mid-latitude and mid-longitude values of the species’ range in the
country as coordinates.
Figure 2 . Frequency distribution of five tracheid traits for 79
conifer species. Blue bars stand for earlywood and red bars for
latewood.
Figure 3 . Phylogenetic PCA of earlywood and latewood characters
for 79 conifer species from five families. Acronyms for tracheid traits
are listed in Table 1. Trait names followed by ‘s’ stand for earlywood
while ‘a’ is for latewood.
Figure 4 . Phylogenetic PCs of earlywood and latewood traits
along the phylogenetic tree. Bubbles stand for Moran’ values for each
species along the phylotree with a legend at the bottom-left. The node-1
label is added to emphasize two clades of the phylotree: Pinaceae
species in the upper part of the phylotree generally showed negative
values, suggesting there are more frequent divergences in traits related
with PC1. On the contrary, Cupressaceae species and others in the lower
branches showed positive values, suggesting xylem traits related with
PC1 of the species were conserved.
Figure 5 . Interspecific variation in tracheid characters along
a latitudinal gradient taking phylogeny into account.
R2 stands for the explanatory power of the climatic
variable in PGLS models, subscript “s” in R2 stands
for earlywood, while “a” stands for latewood. Blue and red lines stand
for fitted GPLS models for earlywood and latewood data, respectively.