FUNGAL POPULATION AND COMMUNITY DEVELOPMENT IN CUT BEECH LOGS: II. ESTABLISHMENT VIA THE BURIED CUT SURFACE

Patterns of fungal colonization from the base of cut beech logs placed upright and partly buried in the ground at a mixed deciduous woodland site were fundamentally different from those from the aerial cut surface. Principal colonists resulting in decay, and mostly arriving within three months, were the ascomycete Xylaria hypoxylon (L. ex Hooker) Greville and various rhizomorph/mycelial cord-forming basidiomycetes, including Armillaria bulbosa (Barla) Kile & Watling, Phallus impudicus (L.) Pers., Phanerochaete velutina (DC ex Pers.) Parmasto and Tricholomopsis platyphylla (Pers. ex Fr.) Sing. Apart from A. bulbosa, these generally readily formed mycelial mats on the basal surface, between which somatic incompatibility reactions were often observed. Most frequent reactions occurred with X. hypoxylon which almost invariably produced numerous individuals in discrete decay columns. By contrast, lack of somatic incompatibility reactions between isolates of A. bulbosa indicated that a single extensive mycelial type occurred throughout the site. The occurrence of somatic incompatibility between isolates off. velutina from different logs indicated independent establishment, presumably via basidiospores, and this was consistent with the unusually late arrival of this species at the site. In no cases were numerous somatically incompatible individuals isolated from small volumes of wood lacking demarcation into discrete columns, as had been observed near the aerial cut surface. Vertical penetration from the base was more rapid than from the aerial cut surface, with X. hypoxylon a major pioneer species, and there was no pronounced lag phase.