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Dioscorea brownii

Assessor: Sarah Schumann

Sensitive in 2010
No
Family
Dioscoreacea
Reason for the sensitivity status
This genus is in demand and of popular interest in international horticultural trade. Other species of this genus are known to be harvested and utilized in local medicinal plant trade and horticultural trade. Few and small subpopulations with existing threat causing population decline makes this species vulnerable to further population loss. Were exploitation to also occur, recruitment and recovery may be poor. Releasing data on this species could exacerbate threat and vulnerability.
This species is either similar to another sensitive species or belongs to a group containing sensitive species, and is extremely rare in the wild. The localities of wild populations need to be protected to avoid loss to exploitation, which, due to its rarity, could drive the species to extinction within a very short time.
Exploitation extent
Uncertain - No data exists yet showing that this species is exploited in the wild, however it has one or more relatives or look-alike species (found in South Africa or globally) that are known to be utilised. This species has a similar life form or other relevant traits to its exploited relative(s), making it highly likely that it would be exploited for the same purposes.
Justification and references

According to the SANBI Red List Assessment, this species is Endangered as its remaining population is small, fragmented and continues to decline due to habitat loss and degradation (Abbott et al. 2016). This genus is currently in demand and of popular interest in international horticultural trade, as indicated by several online marketplace, e-commerce and auction sites.

Abbott, A.T.D., Johnson, I.M., Grieve, G. & von Staden, L. 2016. Dioscorea brownii Schinz. National Assessment: Red List of South African Plants version 2020.1. 

Population vulnerability
Population is vulnerable: size is <= 2500 mature individuals OR the number of known subpopulations is <= 5 OR range is <= 100km2 OR species at risk of localised extinctions
Justification and references

This taxon has an estimated population size of between 300 and 500 mature individuals with five small and fragmented subpopulations (Abbott et al. 2016).

Abbott, A.T.D., Johnson, I.M., Grieve, G. & von Staden, L. 2016. Dioscorea brownii Schinz. National Assessment: Red List of South African Plants version 2020.1. 

Targeted demographics
Unknown.
Regeneration potential
This species has a slow population growth rate, or the growth rate varies depending on habitat, and there is a poor chance the wild populations will recover from exploitation OR a collector might feasibly harvest the entire extant population removing the chance of subsequent recruitment.
Justification and references

Few and small subpopulations with existing threat causing population decline makes this species vulnerable to further population loss. Were exploitation to also occur, recruitment and recovery may be poor. 

Reference file
dioscorea _ eBay.pdf1.04 MB
Dioscorea Aucfan.pdf963.94 KB
Dioscorea Rakuten.pdf507.95 KB
Dioscorea brownii Threatened Species Programme _ SANBI Red List of South African Plants.pdf788.15 KB