ABSTRACT

Although the association between fungi and decaying wood has long been known, it was not until the pioneering work of Robert Hartig in the 1870s that fungi were actually shown to be the cause (Rayner and Boddy 1988). For about 80 years, research focused on heart-rot (i.e., decay of the central tissues of trunks and large branches) as the main cause of decay in standing trees (Rayner and Boddy 1988). Then, and even sometimes now, fungi fruiting on standing trees were/are thought of as pathogens, but if they are only feeding on dead tissues, then they are acting as saprotrophs not pathogens. Nonetheless, some fungi which act as heart rotters using dead tissues, ›nd their way to central tissues by killing living cells, for example, the root pathogenic and butt rotting Armillaria and Heterobasidion species. In the mid-1960s, Alex Shigo drew attention to the fact that colonization of the standing tree is not con›ned to heart wood, but can occur following wounding, with decay usually relatively localized in the vicinity of the wound (Shigo and Marx 1977; Shigo 1979; Rayner and Boddy 1988).