SPATIAL DEVELOPMENT OF POPULATIONS OF A DECOMPOSER FUNGUS, MYCENA-GALOPUS

Past and recent research on the distribution of the vegetative myceliu m and basidiomes of Mycena galopus in a Picea sitchensis plantation is reviewed as an example of a litter-decomposing member of the Basidiom ycotina, occupying a spatially continuous resource that is replenished throughout the year. Using a variety of methods, the mycelia were fou nd to be concentrated in the F-1 horizon and the basidiomes produced n onrandomly in aggregations or arcs around the trees. Evidence was obta ined of rapid dikaryotisation of homokaryons and of the ability to out breed with a strain from Quercus woodland. The dikaryotic mycelia (gen ets) were up to 2.5 m in diameter, perennial or renewable mycelium occ upying longstanding positions. A hierarchy of causal factors, includin g a competing saprotroph, a mycophagous collembolan, and variations in soil properties around tree boles, is discussed. Examination of relat ionships between NH4+-N content, moisture, or pH of the litter acid di stance from a tree or relative positions of basidiomes showed that the re was significantly (P < 0.01) more NH4+-N at the are position than t he average for positions either side and a tendency for pH to reach ma ximum values in this region. The are system with mycelium at its centr e is contrasted with typical free and tethered fairy rings.