Variations in the Anatomical Structure of Ailanthus excelsa Wood with Height on the tree and Radial Distance from the pith

Abstract

Microscopic slides were prepared from 12 locations on ailanthus trees representing three height levels and 4 radial locations at each height level with different distances from the pith. The slides included cross sectional slides and slides for macerated fibers. These slides were examined under the microscope and analyzed using stereological techniques to look for any variations or trends in the anatomical properties with height on the tree and radial distance from the pith. The results were analyzed statistically using analysis of variance and Duncan's Multiple Range test. Results revealed that the average fiber length decreased gradually from top height to bottom height. There were no significant differences in the volume fractions of cell components (cell walls and lumens) between different heights except for fiber lumen and parenchyma lumen, both of which showed a gradual decrease from top height to bottom height. There were no significant differences in volume fractions of different cell components between different zones (radial distance from the pith) except for vessel walls and Parenchyma lumens. With regards to volume fractions of the cell types, the volume fractions of vessels decreased from top height to bottom height, and also decreased from zone 1 to zone 3 and then increased in zone 4. With regards to cell dimensions, average vessel diameters decreased from top height to bottom height. They also decreased from zone 1 to zone 3 and then increased at zone 4- the same trend as for vessel volume fraction. Average fiber diameter increased from zone 1 to zone 4, but no trend was observed between heights. On the other hand, average parenchyma diameter showed the same trend as the vessel diameters with height- decreased from top height to bottom height. It also increased from zone 1 to zone 3 and then decreased in zone 4. Double cell wall thickness, on other hand, increased from top height to bottom height and also from zone 1 to zone 4.