Discovering neglected lichen diversity with DNA-based inventories: metabarcoding lichen-forming fungi in Bryce Canyon National Park, Utah, USA

Abstract

National parks and other federally designated natural areas play critical roles in preserving unique habitats, communities, and biodiversity. However, in the United States, it is estimated that 80–90% of species diversity in national parks is presently unknown. Therefore, contemporary biodiversity inventories are critical for conservation, management and establishing baselines for future comparisons. Ongoing efforts to characterize lichen diversity highlight diverse and robust communities in a number of national parks in the USA. In arid regions of the western USA facing ecological transformations, lichens can play a pivotal role for monitoring these changes. Lichen diversity in Bryce Canyon National Park (BRCA) in southern Utah, USA remains nearly completely uncharacterized, despite nearly 100 years as a federally protected area. Our study aims to provide a critical perspective into the lichen diversity of BRCA. Using a metabarcoding community sampling approach, we documented 215 candidate lichen-forming fungal species distributed across ecologically distinct sites in BRCA. At each sampled site, species richness ranged from 104 to 133 species, with no more than 20% shared species among the three sites. The limited overlap between collection sites suggests that BRCA harbors greater diversity than initially thought. We document a number of sensitive lichens, particularly Usnea spp. and Ramalina sinensis, that should be monitored as air pollution, land use, and impacts of climate change affect biological communities in the park. The inventory also includes unknown species and other species that have not been documented in the western USA. While our DNA-based inventory highlights strikingly rich lichen diversity, future voucher-based collections will be essential for robust taxonomic determinations.