Microscopical investigation on the secondary metabolites deposition in the red heart of beech

Abstract

The beech wood (Fagus sylvatica L.) affected by red heart is characterized by a low durability and an intense brownish coloration. In this report the more frequent deposition typology of the false heartwood secondary metabolites has been documented. The secondary metabolites placing inside the cells seems to happen in three fundamental forms: under shape of spherical elements; under shape of layer on the cell walls; in the extreme cases the metabolites content completely fills up the cellular lumen. These metabolites function is that of a mechanical barrier against several adversities, that include the attack of some pathogenic agent, but also the simple loss of the humidity tenor in wood which is not more efficient in the water transport.