Table 1.

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

ParameterNo girdleFull girdlePartial girdle
Cross-sectional surface area (μm2)16306az±881 y16833a±88117683a±1970
Number of functional vessels671b±78574b±781207a±175
Xylem vessel diameter (μm)x0.085a±0.0060.080a±0.0050.072a±0.010
Total functional xylem area (μm2)w58ab±843b±888a±15
Conductive area (%)v0.34a.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%.