3.3 Plant-environment relationships
Redundancy analysis (RDA) was applied to further investigate the
contribution of soil water content and electrical conductivity to
functional traits of P. australis . As shown in Figure 3, selected
environmental variables completely explained 15.43% of the variance in
functional trait variables (F=7.8, P<0.01). The first axis
explained 14.34% in the ordination with electric conductivity. The
second axis explained 1.08%, with soil water content. The relationships
with electrical conductivity were negative, including SPAD, height, and
stem traits, but the functional trait variables had almost no
correlation with soil water content. The response of leaf traits to
environmental variables were inconsistent. Leaf water content had
positive relationships with soil water content and electrical
conductivity. Leaf thickness had a strong positive relationship with
electrical conductivity, while leaf area and specific leaf area had
strong negative correlations with electrical conductivity.