Fifty shades of red: Lost or threatened bryophytes in Africa

Background: A Red List of threatened bryophytes is lacking for Africa. The International Union for Conservation of Nature (IUCN) Species Survival Commission (SSC) Bryophyte Specialist Group has recently launched the ‘Top 10 Initiative’ to identify the 10 species on each continent that are at highest risk of extinction. Objectives: The main aim of this paper was to highlight some of the lost or strongly threatened bryophyte species in sub-Saharan Africa and the East African islands and to draw up a Top 10 list for Africa. Method: Lost or threatened species have been identified with the help of experts on the bryoflora of Africa, global and regional Red Lists and taxonomic literature. Each species on this candidate list is discussed at the hand of its taxonomy, distribution, habitat, threat and current global or regional Red List status as far as previously assessed. Results: Fifty bryophyte species, representing 40 genera and 23 families, have been identified as Top 10 candidates. Of these, 29 are endemic to Africa and 21 are restricted to the East African islands. The majority of the candidate species occur in one of eight ‘biodiversity hotspots’ with most species (19) in the Madagascar and the Indian Ocean Islands hotspot. Conclusion: This is the first list of lost or threatened bryophytes for Africa and the first Top 10 list of the IUCN Bryophyte Specialist Group. It represents an important step towards regional and global Red List assessment of bryophytes, thus meeting the targets of the Updated Global Strategy for Plant Conservation 2011–2020 and priorities of The Shenzhen Declaration on Plant Sciences