Wood structure and quality in natural stands of Salix caprea L. and Salix pentandra L.

Wood anatomy and physical properties in Salix caprea and S pentandra growing at different sites in Sweden were investigated. The mean length of fibres was 0.8 mm and of vessels 0.4 mm in both species. The length of the tracheary elements increased in a gradient from the pith towards the cambium in the transverse section of the wood. Longitudinally the cell length increased from the base to breast-height (1.3 m) followed by a decrease towards the top of the tree. No significant differences were found between the two species in this respect. Mean width of fibres was 2 1 µm in both species, vessel width was significantly greater in S. caprea (82 µm) than in S. pentandra (74 µm). Type and distribution of cells and cell wall thickness was similar in both species. Cell dimensions within the annual ring were investigated. The mean specific gravity of stem wood (0.48 g. cm-3) branches (0.46 g cm-3) also in the bark (0.40 g cm-3) In Salix caprea was significantly higher than in S. pentandra, which species had a significantly higher moisture content in the stem wood and branches. Bark percentage was higher in S. pentandra than in Salix caprea