Wymierne cechy elementów przewodzących w drewnie

The trade−off in case of water transport is captured in ecological theory by the safety vs. efficiency concept. As the efficiency of transport of water depends mainly on the dimensions of the con− ductive elements in wood, this paper presents the survey on some methods that allow to quantify the tracheids and vessels attributes including their diameter (tangential/radial, hydraulic), length as well as arrangement (axial, radial). Each trait of conductive elements is briefly described and formula for its calculation is given. Moreover, the usefulness of measurable traits for calculating the meso− and xeromorphy index is presented. Given the fact that the structure of pits and com− plexity of perforation plate (scalariform, ladder−like) are important factors in wood hydraulic resistance, the following parameters were additionally characterized: the pit membrane diameter, pit membrane thickness, pit chamber depth and the number of bars per perforation plate between the adjacent vessel elements.