Figure 6.

Relationship of sieve element end wall type and native climate zone, leaf length and growth rate. (a) Relationship between native climate zone and end wall type of woody angiosperms, 161 with simple and 242 with compound end walls. (b) Relationship between stem length and leaf length as an indicator of source capacity for woody angiosperms with simple end walls (blue circles) and compound end walls (orange diamonds). Average values are indicated by a dotted line for angiosperms with compound end walls and by a broken line for angiosperms with simple end walls. (c) Box plot of growth rates (annual mass increase) of mature trees of groups with different end wall types. Error bars indicate ± SD.