Lichen secondary chemistry variation across environmental gradients in Arctic Alaska: Possible targets for functional trait exploration

Studies abound describing community structure of lichens across various landscapes. However, much of this work only uses lichen identity and abundance, with fewer studies using functional traits to describe these patterns. We believe that lichen chemistry represents a promising possible functional trait with which to investigate lichen ecosystem function, but current literature has yet to define species targets for investigation. We developed a bibliographic database of secondary metabolites documented to occur in Arctic lichen species. Using these chemical data, in conjunction with existing field datasets across the Arctic National Parklands, USA, yielded species abundance-weighted mean chemical frequency. Ordination analysis revealed three primary gradients in lichen chemistry. We found that lichen chemistry community patterns were not random. We recommend nine secondary chemicals, which are strongly associated with these environmental gradients as targets for future chemistry-based functional trait research. This novel approach has utility well beyond simply characterizing the community through the lens of lichen chemistry.