Table 1.

Cross-sectional and conducting xylem element parameters for roots of Fraxinus pennsylvanica seedlings for each of the root wire girdling treatments.

Parameter	No girdle		Full girdle		Partial girdle
Cross-sectional surface area (μm²)	16306a^z	±881 ^y	16833a	±881	17683a	±1970
Number of functional vessels	671b	±78	574b	±78	1207a	±175
Xylem vessel diameter (μm)^x	0.085a	±0.006	0.080a	±0.005	0.072a	±0.010
Total functional xylem area (μm²)^w	58ab	±8	43b	±8	88a	±15
Conductive area (%)^v	0.34a		.29a		.49a

↵^zvalues are the mean of seven independent replications, mean separation in rows at the 5% level.
↵^ystandard error
↵^xvalues are an average of 20 vessels in each of four quadrants.
↵^wnumber of functional xylem x xylem vessel diameter.
↵^vtotal functional xylem area _ cross sectional surface area × 100%.