The Rusty Cord-moss was initially assessed as endangered by COSEWIC. In 2006, the species was added to Schedule 1 to the Species at Risk Act with that status. In April 2017, the species was reassessed by COSEWIC as special concern. To explain this change in status, the scientific body stated in its assessment that, as a result of field and collection research, the known distribution and abundance of the moss had increased significantly since the species was first assessed by COSEWIC in 2004, resulting in decreased extinction risk. The 2017 assessment further indicated that the species is now known to occur in both British Columbia and Saskatchewan.
The expert shared research reports, which included surveys from 2018 to 2020. The reports describe significant changes since the 2017 COSEWIC status report, including important population declines at two of the species’ largest known occurrences in Canada (by 93–96% near Riske Creek, British Columbia, and by 100% at White Lake, British Columbia). As the main drivers of these changes, the expert identified a landscape-scale fire in 2017, which passed across three of the known sites at Riske Creek, and an invasive exotic grass growth in a number of habitats at White Lake. In addition, although the species was listed as present on many sites in British Columbia in 2017, it was not observed during the surveys that were conducted from 2018 to 2020 and could be, according to the expert, extirpated on these sites.
Based on this new information, the Minister of the Environment is of the view that a more thorough analysis of this new evidence and all other available information should be undertaken to determine whether the current classification of the Rusty Cord-moss as endangered is appropriate or whether the species should be assessed and reclassified as special concern. Therefore, the matter is referred back to COSEWIC for further information or consideration. The Department of the Environment is committed to working with COSEWIC on this matter.