On the occurrence of trabeculae with special consideration of diseased trees

Abstract

Comprehensive investigations on trabeculae in softwoods have shown that they occur much more frequently than has hitherto generally been assumed. A systematic study oflarge series of microtome sections, i.e., transverse sections and particularly radial sections of extended annual ring sequences will, as a rule, give sufficient evidence for the occurrence of trabeculae and related structures. Apart from this phenomenon an increased occurrence of trabeculae was often found in the annual rings of healthy and diseased trees from forest decline areas from the middle of the 1970's onwards. Moreover, trabeculae occur with particularly great frequency and in significantly larger numbers than in nonnal wood in association with wound tissue fonnation as a consequence of injuries, in spruce with hazel growth, or in cedars with traumatic resin ducts. Also, in compression wood trabeculae are fonned much more often than in normal wood. A detailed survey of trabeculae structure and possible patterns of trabeculae arrangement is also given.