Aloidendron pillansii | SANBI Sensitive Species

Assessor: Sarah Schumann

Sensitive in 2010

Family

Asphodelaceae

Reason for the sensitivity status

The illegal removal of wild quiver trees like this species is a major threat to the species. This genus is very popular in trade, and that there is a high demand. Few known subpopulations with several threats including exploitation makes this species vulnerable to further population loss. Releasing data on this species could exacerbate threat and vulnerability.

This species is extremely rare in the wild and is known to be exploited, utilised or traded. The localities of remaining populations need to be protected to avoid any further exploitation, which is likely to drive it to extinction.

Exploitation extent

Significant - wild individuals of the species are known to be exploited, collected, traded or utilized in a targeted manner, and utilisation is widespread, affects the majority of wild populations and/or is causing rapid decline of the wild population.

Justification and references

According to the SANBI Red List Assessment, this species is Endangered as it is a range-restricted endemic experiencing ongoing population decline due to climate change, theft by illegal succulent collectors and herbivory (Swart et al. 2015; Duncan et al. 2006). The illegal removal of wild Quiver Trees like this species, from the Northern Cape is still a major threat (Cousins & Witowski, 2012). This species has lost half of its population size in the decade prior to 2003 (Cousins & Witowski, 2012). An internet survey indicated that this genus is very popular in trade, and that there is a very high demand. Plants of this genus were among those targeted and/or confiscated during a recent criminal prosecution of illegal plant collecting. There has been several recorded confiscations of the genus from illegal collection (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; Cousins & Witowski, 2012). 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).

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.

Duncan, J., Hoffman, T., Rohde, R., Powell, E. and Hendricks, H., 2006. Long-term population changes in the Giant Quiver Tree, Aloe pillansii in the Richtersveld, South Africa. Plant Ecology, 185(1), pp.73-84.

Swart, E., Foden, W., Raimondo, D. & Van Wyk, P.C.V. 2015. Aloidendron pillansii (L.Guthrie) Klopper & Gideon.F.Sm. 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 extent of occurrence of 302 km² with one or two known subpopulations (Swart et al. 2015).

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

Swart, E., Foden, W., Raimondo, D. & Van Wyk, P.C.V. 2015. Aloidendron pillansii (L.Guthrie) Klopper & Gideon.F.Sm. National Assessment: Red List of South African Plants version 2020.1.

Targeted demographics

Mature (breeding) individuals are killed, significantly weakened or are permanently removed from the wild, OR immature individuals are targeted and this significantly impacts mature (breeding) individuals.

Justification and references

Seedlings are removed (Duncan et al. 2006).

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

The loss of seedlings that subpopulations have experienced may result in the species extinction due to loss of recruitment (Duncan et al. 2006). High levels of endemism and a restricted range makes this species vulnerable to population loss. Harvested populations can result in having fewer flowers per flowering plant and a reduced proportion of young recruits (Shackleton & Gambiza, 2007).

Shackleton, C.M. and Gambiza, J., 2007. Growth of Aloe ferox Mill. at selected sites in the Makana region of the Eastern Cape. South African Journal of Botany, 73(2), pp.266-269.

Reference file

Swart et al 2015 Aloe pillansii Threatened Species Programme _ SANBI Red List of South African Plants.pdf873.43 KB

aloidendron _ eBay.pdf638.69 KB