INTERACTIONS OF FUNGI AT LATE STAGES OF WOOD DECOMPOSITION

Species of wood-rotting fungi succeed each other during the decomposit ion of a tree trunk; details of this succession vary from tree to tree . Besides the general pathways of fungal decomposition, another and st ricter kind of succession exists. Over twenty species of fungi, mostly polypores, were found to inhabit such trees which were previously dec ayed by certain other species. The successor emerges only after the pr eceding fungus has died, and often fruits on dead basidiocarps of the previous one. Most predecessors occupy large volumes of the trunk. Fom es fomentarius (L.: Fr.) Fr., Fomitopsis pinicola (Sw.: Fr.) P. Karste n, Hymenochaete tabacina (Sowerby: Fr.) Lev., and species of Inonotus P. Karsten and Trichaptum Murr. serve frequently as preceding species. Certain genera of polypores include exceptionally many species that h ave this kind of successional preference: Antrodiella Ryvarden & Johan sen and its close kin Junghuhnia Corda, as well as Skeletocutis Kotl. & Pouzar and related Piloporia Niemela. Fungi which intimately depend on other species are especially vulnerable and deserve special attenti on in nature conservation. In most cases they survive in virgin forest s only, and seem to be rare also there. Even a slight decrease in the abundancy of the preceding species may drastically suppress the popula tions of the successor, or cause their disappearance.