Variation in specific gravity, fiber length, fiber dimensions, and volumetric composition were investigated for selected heights and growth rings of five Mississippi Delta hardwood species: black willow, willow oak, sycamore, pecan, and sugarberry. Variation of specific gravity with age of the cambium was not only different from species to species, but was also different at different sampling heights. The fiber length-age relationship in study trees conformed to the general pattern of large increases in fiber length with age in rings near the pith, followed by a more gradual increase until a maximum was reached. Variations in fiber diameter were not great, but in all species, cell diameter decreased as height in the stem increased. Thin-walled fibers were found near the pith and thick-walled fibers developed in the outermost growth increments.Volumetric composition data revealed large variations between sampling points. The general pattern with age was a linear or curvilinear increase in vessel volume with a corresponding decrease in fiber volume, while ray volume remained constant or increased slightly with age.Correlation analysis was used to evaluate the interrelationships of measured properties in three different species (willow, sugarberry, and pecan). Wide growth rings in these species contained proportionately fewer vessels and more fibers than narrow growth rings as well as shorter fibers. High specific gravity was associated with increased fiber volume. However, the analysis showed no significant differences in specific gravity resulting from variations in growth rate
