Natural loosening of the wood/bark bond: a review and synthesis
1990
Kubler, H.
Forest products industries usually debark trees by machine, but the bark also loosens naturally and there are some cases in which it is desirable that the bark remain attached. The bond of bark to wood varies seasonally. Under suitable conditions, microorganisms dissolve the bond, consuming the barely visible cambial sheath that bonds bark to wood. The cambium is not lignified and therefore is ready food for fungi and bacteria. The microorganisms decompose cambium much faster than they do the main constituents of wood and bark, thus they separate the bark from the tree stems long before they weaken the wood and bark. This article reviews information related to the conditions under which microorganisms separate bark from wood, and the rate of this microbiological debarking. Under optimal conditions, bark may come off within a few days. Delayed loosening of the bark following "chemical debarking" is explained by the action of microorganisms. Seasonal variations of bark adhesion are included, since they occur not only on standing live trees but also on felled trees. Drying enforces the bark/wood bond, and steaming loosens it.
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