A comparison of decomposition of jack pine and trembling aspen wood blocks by eight wood decay fungi

Abstract

Decay is an important component of the carbon cycle, as it breaks down wood and releases the stored carbon back into the atmosphere. White rot, brown rot, and soft rot are all types of decay which initiate this process. To test if fungi are host specific, break down wood at different rates, and are dependant on host species x fungus interactions, a study was conducted using two species of wood (Pinus banksiana and Populus tremuloides) and eight fungi (Trichaptum abietinum, Fomitopsis cajanderi, Gloeophyllum separium, Fomitopsis pinicola, Trametes pubescens, Bjerkandera adusta, Ganoderma appanatum, and Phellinus ignarius). Small pre-weighed blocks of Pinus banksiana and Populus tremuloides were aseptically inoculated with mycelium of each of the eight fungi and final dry weights of the blocks were taken, after 3 months of incubation, to determine the percent rate of decay. Both Pinus banksiana and Populus tremuloides experienced a decline in weight for all eight fungus species. However, Anova testing showed that there was no significant difference in the percent rate between the two wood types, but there was a difference between the fungi and the fungi x wood species interaction. The two Fomitopsis species caused the most statistically significant difference in the dry weight of trembling aspen blocks, while Fomitopsis pinicola caused the most statically significant difference in dry weight of jack pine blocks. Although both Fomitopsis species are primarily conifer-inhabiting, the ability to decay hardwood blocks suggests that ideal lab conditions may alter fungal species ecological strategies compared to less than idea natural conditions in the field.