Figure legends
Figure 1 Relationship of hydraulic and anatomical traits
between branches and roots: (a) P 50, water
potential at a 50% loss of hydraulic conductivity; (b)K S, specific xylem conductivity per unit of
cross-sectional sapwood area; (c)t 2/b 2, vessel wall
reinforcement; (d) D h, hydraulically weighted
mean diameters (the x-axis and y-axis were natural log-transformed).
Dashed line represents the 1:1 relationship. The coefficients of
determination (r 2) of the simple linear
regression models were marked. Each point denotes a species. Insert:
comparison of traits between branches and roots. Boxes and whiskers
represent the minimum, 25th percentile, median, 75th percentile, and
maximum values in each bin, respectively. Solid points are outliers
(data points located outside the whiskers of the boxplot). Numbers in
the brackets are sample sizes. *** P < 0.001.
Figure 2 Relationships between P 50(water potential at a 50% loss of hydraulic conductivity) and
anatomical traits
(t 2/b 2, vessel wall
reinforcement; D h, hydraulically weighted mean
diameters) of branches and roots: (a)t 2/b 2 in branches, (b)t 2/b 2 in roots, (c)D h in branches, (d) D h in
roots (the x-axis and y-axis were natural long-transformed). Each point
denotes a species (branch traits: filled dark yellow circles and
root traits: filled dark red triangles ). ***, P< 0.001.
Figure 3 Relationships between P 50 root -
branch (hydraulic vulnerability segmentation between root and branch)
and hydraulic traits (P 50, water potential at a
50% loss of hydraulic conductivity; K S, specific
xylem conductivity per unit of cross-sectional sapwood area) of branches
and roots: (a) P 50 of branches, (b)P 50 of roots, (c) K S of
branches, (d) K S of roots (the x-axis and y-axis
were natural long-transformed). Each point denotes a species (branch
traits: filled dark yellow circles and root traits: filled
dark red triangles ). Dashed line in (b) indicates nonsignificant
correlations. Significance: ***, P < 0.001; **, 0.001 ≤P < 0.01.
Figure 4 Comparisons of hydraulic vulnerability segmentation
(P 50 root - branch) and hydraulically weighted
mean diameter (D h) across different biomes: (a)P 50 root - branch, (b) D hof branches, (c) D h of roots. Boxes and whiskers
represent the minimum, 25th percentile, median, 75th percentile, and
maximum values in each bin, respectively. Solid points are outliers
defined as data points located outside the whiskers of the boxplot. The
horizontal short dashed line indicates that P 50
root - branch is equal to zero (a). Mean values of AI for different
biomes are shown (a). The numbers in the brackets are sample sizes.
Different letters indicate statistically significant differences atP < 0.05 (one-way ANOVA). Inset: relationships betweenP 50 root - branch and aridity index (AI) (a),
relationships between D h and AI of branches (b)
and roots (c) (the x-axis and y-axis were natural log-transformed)
across biomes. Each point denotes one species [filled green
circles , tropical seasonal forest (TRS); filled aquamarine
circles , temperate seasonal forest (TMS); filled dodger blue
circles , woodland and shrubland (WDS); and filled purple
circles , desert (DES)]. Dashed line in (c) indicates nonsignificant
models. Significance: ***, P < 0.001; **, 0.001 ≤P < 0.01.