Aloe gerstneri | SANBI Sensitive Species

Assessor: Sarah Schumann

Sensitive in 2010

Family

Asphodelaceae

Reason for the sensitivity status

This species was heavily collected in the past which impacted the small and localized population but such collecting is thought to have stopped and now most aloe species are established in cultivation. Plants of this genus were among those targeted and confiscated during a recent criminal prosecution of illegal plant collecting. Few known locations of occurrence 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 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 it is known from few locations that is experiencing population decline due to ongoing habitat loss and degradation (Mtshali et al, 2018). This species was heavily collected in the past which impacted the small and localized population but such collecting is thought to have stopped and now most aloe species are established in cultivation (Van Wyk and Smith 2003). This genus is in demand and of popular interest in international horticultural trade, as indicated by several online marketplace, e-commerce and auction sites. Plants of this genus were among those targeted and confiscated during a recent criminal prosecution of illegal plant collecting (Confiscation Lists (2018-2021) provided by Cape Nature, SANBI Karoo Desert Botanical Garden and Kirstenbosch Botanical Garden). Aloe species are widely utilised for traditional and medicinal purposes and are also popular in domestic and international horticulture trade (Grace, 2011). Many wild aloe species are threatened by over-exploitation for the succulent plant trade as well as over-utilisation for cosmetics and natural products which makes rare, endemic and utility taxa conservation priority (Grace, 2011). It is believed that the most sought after and so potentially vulnerable species among plant collectors, are rare endemics and difficult to grow species (Cousins & Witkowski, 2012). This suggests that this genus may be targeted and that this species may be at risk.

Cousins, S.R. and Witkowski, E.T.F., 2012. African aloe ecology: a review. Journal of Arid Environments, 85, pp.1-17.

Grace, O.M., 2011. Current perspectives on the economic botany of the genus Aloe L.(Xanthorrhoeaceae). South African Journal of Botany, 77(4), pp.980-987.

Mtshali, H., Victor, J.E., van Wyk, E. & Smith, G.F. 2018. Aloe gerstneri Reynolds. National Assessment: Red List of South African Plants version 2020.1.

Van Wyk, B.-E. and Smith, G. 2003. Guide to aloes of South Africa. (2nd ed.). Briza Publications, Pretoria.

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 extent of occurrence of 334 km² and is known from 3-5 locations (Mtshali et al, 2018).

Mtshali, H., Victor, J.E., van Wyk, E. & Smith, G.F. 2018. Aloe gerstneri Reynolds. 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 known locations of occurrence with existing threat (Mtshali et al, 2018), causing population decline makes this species vulnerable to further population loss. Were exploitation to also occur, recruitment and recovery may be poor.

Mtshali, H., Victor, J.E., van Wyk, E. & Smith, G.F. 2018. Aloe gerstneri Reynolds. National Assessment: Red List of South African Plants version 2020.1.

Reference file

aloe _ eBay.pdf643.68 KB

Aloe Aucfan.pdf468.22 KB

Aloe gerstneri Threatened Species Programme _ SANBI Red List of South African Plants.pdf780.37 KB