Investigation of six anatomical and four statistical features of bald-cypress ( Taxodium distichum) tree rings

Abstract

A tree-ring study was conducted to determine if growth rings on core samples from bald cypress ( Taxodium distichum (L.) Rich.) differed significantly in anatomical and statistical features depending on where on the tree the sample was taken. The variables studied were compass direction and surface geometry of the trunk. If significant differences exist, then standardization of core type could provide a higher-quality sample and a more reliable variance measurement for the comparison of tree-core data from different trees. The trunk of bald cypress is often irregular in circumference, forming lobes and furrows. Eight core types were sampled on each tree: north lobe, north furrow, south lobe, south furrow, east lobe, east furrow, west lobe, and west furrow. When anatomical and statistical features were compared, no significant difference in ring-width data was measured that was attributable to compass direction of the core site, with one exception: cores from south furrows had a significantly greater number of missing and merging rings when compared to other furrow cores. Furrow samples were found to have significantly more missing and/or merging rings and significantly fewer false rings than lobe samples. The number of apparent ring-shakes was found to differ significantly among trees. The effect of core type, i.e. compass direction or lobe versus furrow, on ring-width data appears to depend on the year the growth ring was formed.