Lichen conservation in North America: a review of current practices and research in Canada and the United States

Lichens are diverse symbiotic organisms that contribute essential functions to ecosystems worldwide. Generally, lichens are under-represented in conservation assessments and implementation when compared to other groups of organisms (e.g., plants and vertebrates). However, some progress has been made towards better conservation of lichens in recent decades. Here we review the current state of lichen conservation in Canada and the United States, a region that includes nearly 6000 species of lichens. Through detailed case studies, we document threats and declines of diversity and abundance, then review the legal frameworks that exist to protect lichens at different spatial scales in both countries. We highlight progress in effectively using 'Big Data' to inform conservation, monitoring rare and endangered species, expanding the professional capacity of lichenologists, and building interdisciplinary networks between scientists and the broader community of conservation and resource managers. Moving forward, there are clear actions that must be taken to accelerate lichen conservation.