LATEWOOD DENSITY IN RELATION TO WOOD FIBER DIAMETER, WALL THICKNESS, AND FIBER AND VESSEL PERCENTAGES IN QUERCUS-ROBUR L

To elucidate the influence of growth rate and cambial age on latewood density in oak (Quercus robur L.), the diameter and wall thickness of libriform fibres, and percentage of latewood area occupied by librifor m fibres and vessels, were analysed across discs of ten 87-year-old oa k trees from Germany. Fibre wall material per unit fibre area did not vary significantly with cambial age, since increase in fibre diameter with ring number from the pith was offset by increase in wall thicknes s. There were no significant variations in fibre diameter or wall thic kness with latewood width. Changes in latewood density with cambial ag e or with growth rate were primarily associated with changes in tissue percentages per unit area, latewood density being more closely correl ated with vessel than with fibre percentages. There appeared to be a c urvilinear relationship between latewood width and latewood density, d ensity reaching a maximum when latewood width was about 2 mm.