Lichen Biodiversity under Threat from Sea-Level Rise in the Atlantic Coastal Plain

Sea-level rise (SLR) and changes in temperature and weather patterns have been documented and are projected to increase substantially. Although changes in temperature and weather are well-studied drivers of climate change-mediated biodiversity loss, the study of SLR remains anthropocentric. Even under conservative estimates, SLR will imperil four coastal regions. The areas most threatened by SLR are not considered global conservation priorities, because the delineation of biodiversity hotspots is based on well-studied organisms and the assumption that the biodiversity patterns of lesser-known groups mirror theirs. We show the Atlantic Coastal Plain hosts a previously overlooked lichen biodiversity hotspot imminently threatened by SLR; all of the highest-diversity sites in the region will be inundated within the century according to conservative SLR projections. The exclusion of lesser-known but diverse, ecologically important groups from global biodiversity assessments has crucial implications for conservation strategies.