Calicium sequoiae is narrowly endemic to old-growth Coast Redwood forests in California where it grows on the bark of redwood trees. Its extent of occurrence is 5,083 km2 and its area of occupancy is 32 km2. There are estimated, ongoing declines in the extent and quality of habitat and inferred ongoing declines in the extent of occurrence, area of occupancy, and number of mature individuals due to logging, climate change, and large, high-intensity wildfires. Its subpopulations have been severely fragmented by large-scale timber harvesting that has resulted in only ca. 5% of old-growth coast redwood forests remaining intact today. Therefore, it is assessed as Endangered: B2ab(i,ii,iii,v).
Assessor/s: Reese Næsborg, R. ; Reviewer/s: Allen, J.; Facilitator/s & Compiler/s: Lymbery, C. & Allen, J.