COMPETITIVE HIERARCHIES OF WOOD DECOMPOSING BASIDIOMYCETES IN ARTIFICIAL SYSTEMS BASED ON VARIABLE INOCULUM SIZES

In the laboratory, 12 species of wood decay basidiomycetes from variou s stages of fungal succession in logs of Norway spruce were investigat ed for their relative competitive ability. ''Pie slices'' of different sizes were cut from wood discs made from Norway spruce. After inocula tion, the pieces were confronted in most species combinations on water agar in Petri dishes, and were left for six months. With this method the inoculum sizes could be varied, while the contact area remained th e same. Photos of the discs were taken regularly during this time. At the end of the experiment, samples of the wood were taken from all dis cs and the remaining fungi were isolated. Combative success was measur ed as the ability to take over substrate from competing species by the end of the experiment. Both within and among successional stages, myc elial replacement occurred in a non-random fashion. Species usually pr oducing fruit bodies in the later stages of succession in the held wer e strong competitors in the laboratory tests, while the species which often fruit during the earlier stages of field succession were weaker competitors.