Fibre Length in Relation to the Distance from vessels and contact with rays in Acacia Mangium

Abstract

Fibre length, as a function of radial or tangential distance from a vessel was estimated from serial cross sections. This new method is easier and faster than earlier methods which rely on photographic prints of transverse images for the analysis. When necessary virtual tangential and radial sections were produced from 3D data to enable fibre length estimation. Fibre length up to the 5th and 2nd fibres away from a vessel in radial and tangential directions, respectively, were significantly shorter than fibres at greater distance from the vessels. Fibre length strongly correlated with radial vessel distance (r = 0.83) up to the 5th fibre and then leveled off. Vessel-adjacent fibres on the radial or tangential side of a vessel did not significantly differ in length. However, the rate of length increase differed significantly in the radial and tangential directions. Percentage of contact with rays varied independently of fibre length.