Small temperature changes alter wood decay. Wood inhabiting fungi metagenome

Forests are important for carbon sequestration, with woody materials representing a significant carbon pool. Wood decay fungal communities are key to the fate of this carbon, either returning it to the atmosphere in the form of carbon dioxide or to the soil in the form of recalcitrant residues. With warming global temperatures, decay rates may increase, potentially leading to increasing levels of atmospheric carbon dioxide. This increase in carbon release could be accelerated or offset by changes in fungal communities, given that some fungi (e.g. brown or soft rot species) may shuttle more carbon to slowly cycling soil pools, while other fungi (e.g. white rot species) may return more carbon to the atmosphere. In order to study the effects of changes in temperature on fungal communities, we used metabarcoding methods to characterize fungal community composition in small diameter stem sections of balsam fir (Abies balsamea) and aspen (Populus tremuloides) incubated at 8 temperatures (4C to 34C). Fungal community composition was assessed before and after incubation using two primer pairs and changes in decay rate and lignin content were also measured.