Cell Wall and Lumen Percentages in Relation to Wood Density of Nothofagus Nervosa

Abstract

Cell wall and lumen percentages were determined for vessels, fibres and rays from 10 trees of Nothofagus nervosa (rauli), and analysed in relation to ring number from the pith, ring width, and density. Increase in density across the juvenile wood was mainly associated with an increase in fibre wall %, which outbalanced a simultaneous increase in vessel lumen %. Decrease in density across the mature wood was associated with changes in both fibre wall and total lumen percentages. Though density varied only slightly with ring width, this was accompanied by appreciable changes in percentages of different cell types. These trends in the wall and lumen percentages of the various cell types suggest that some physical properties may vary more within the tree (or with growth rate) than is suggested by the limited variation in density that is found in rauli. There were significant between-tree variations in both density and cell types, indicating the possibility of selection for either at an early stage of tree growth.