Stomatal conductance (g
) showed a similar trend
except that values were greatest for category 4 leaves of G. robusta
and P. fortunei (Fig. 4c). WUE
i
s
was greatest for category 3 leaves and
similar in all tree species (Fig. 4d). Age-related changes were
significant for all variables (p < 0.001) and species differences were
significant for all except WUE
(p < 0.001). Maximum A values were
18.0, 13.0 and 11.7
mmol m
i
2
s
1
for P. fortunei, A. acuminata and
G. robusta; the corresponding values for E were 6.3, 3.9 and
3.6 mmol m
2
s
1
.