Chlorociboria spp. are soft-rot ascomycete fungi notable for their production of a bright blue-green pigment called xylindein. Pigment applications range from use as a semiconductor to an artistic colorant, however the biological function is not known. As Chlorociboria spp. are slow growing and commonly found on heavily decayed wood, it is hypothesized that the pigment may restrict competitive microbial growth. To test this, an ecological experiment is being carried out to measure the impacts of xylindein on fungal community structure. Wooden stakes 1/8”x 1.5”x 10” in size including Douglas fir (Pseudotsuga menziesii (Mirb.) Franco), big leaf maple (Acer macrophyllum Pursch), and alder (Alnus rubra Bong.) were either left untreated or were treated with an extracted solution from pigmented wood. Stakes were set out near five downed trees showing pigmentation associated with Chlorociboria spp. for 6 or 18 months prior to harvesting for DNA extraction and metabarcoding analysis. In addition, decaying wood in the vicinity of the test sites and other Oregon locations was collected and included in the analysis to profile native communities associated with Chlorociboria. Differences in fungal community structure resulting from pigment presence were seen, including decreased species richness and diversity in pigmented wood. To further test pigment function, controlled decay tests following AWPA standard E10-21 will be carried out on pigmented and non-pigment treated wood using fungal isolates from profiled communities and standard test fungi. Results of decay testing will validate effects of fungal pigment seen in community analysis, indicating modulation of interspecific species by Chlorociboria pigment.
