Encephalartos senticosus

Assessor: Sarah Schumann

Sensitive in 2010
No
Family
Zamiaceae
Reason for the sensitivity status
This taxon is sensitive as it is threatened with illegal collection of wild individuals, causing population decline. Evidence shows that the Encephalartos genus is in high demand in international trade for ornamental and horticultural purposes as well as local medicinal purposes. The species has a small remaining population size with multiple existing threats, making it vulnerable to further population loss. Releasing data on this species can exacerbate threat and vulnerability.
This species is threatened by widespread, unregulated, unsustainable exploitation of wild populations. 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

All South African cycads as well as this species is included in Appendix I of the CITES Convention which lists all species threatened with extinction that are, or may be affected by trade. According to the SANBI Red List Assessment, this species is Vulnerable as it is threatened by over-collection and removal from the wild due to poaching (Bosenberg 2009; Donaldson 2003). The population has declined by more than 30% in the past 60 years (Bosenberg 2009; Donaldson 2003). Cycad species are in trade demand and at risk from illegal collection (Smith 2014; Yeld 2014). Studies present strong evidence of ongoing and accelerating rates of decline in most cycad species due mainly to illegal removal (Okubamichael et al. 2016; Cousins & Witkowski 2017).Research shows that this species is illegally harvested for medicinal trade and has been identified for sale at two traditional medicine markets in South Africa (Williamson et al. 2016). The CITES Trade Database has recorded the trade of the species from 1996-2019 for commercial, personal, scientific, education, artificial propagation and botanical garden purposes. Sourced from artificial propagation, and taken from the wild. This all suggests that this genus is being targeted and that this species may be at risk.

Bosenberg, J.D. 2009. Encephalartos senticosus Vorster. National Assessment: Red List of South African Plants version 2020.1. 

CITES trade statistics derived from the CITES Trade Database, UNEP World Conservation Monitoring Centre, Cambridge, UK.

Cousins, S.R. and Witkowski, E.T.F., 2017. African cycad ecology, ethnobotany and conservation: a synthesis. The Botanical Review83(2), pp.152-194.Donaldson, J.S. 2003. Cycads. Status survey and conservation action plan. IUCN/SSC Cycad Specialist Group, Gland, Switzerland; Cambridge, UK.

Okubamichael, D. Y., S. L. Jack, J. D. Bösenberg, M. T. Hoffman & J. S. Donaldson. 2016. Repeat photography confirms alarming decline in south African cycads. Biodiversity Conservation 25(11): 2153–2170.

Smith, D. 2014. 1 September 2014. South Africa's ancient cycad plants under threat from poachers. The Guardian. Available at: https://www.theguardian.com/world/2014/sep/01/ancient-cycad-plants-under-threat-poachers

Williamson, J., Maurin, O., Shiba, S.N.S., Van der Bank, H., Pfab, M., Pilusa, M., Kabongo, R.M. and Van der Bank, M., 2016. Exposing the illegal trade in cycad species (Cycadophyta: Encephalartos) at two traditional medicine markets in South Africa using DNA barcoding. Genome, 59(9), pp.771-781.

Yeld, J. 2014. 7 August 2014. Cycad thieves strike again. IOL. Available at: https://www.iol.co.za/news/cycad-thieves-strike-again-1731799

Population vulnerability
Population is not vulnerable: size is > 2500 mature individuals, AND the number of known subpopulations is > 5 AND range > 100km2
Justification and references

According to the IUCN Red List, there are 5 000-10 000 mature individuals remaining in the wild (Donaldson 2010). The population is projected to decline a further 10% in the next three generations (Bosenberg 2009).

Bosenberg, J.D. 2009. Encephalartos senticosus Vorster. National Assessment: Red List of South African Plants version 2020.1. Donaldson, J.S. 2010. Encephalartos senticosusThe IUCN Red List of Threatened Species 2010: e.T41925A10600018. https://dx.doi.org/10.2305/IUCN.UK.2010-3.RLTS.T41925A10600018.en.

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

The CITES Trade Database has recorded the trade of live individuals, leaves, and seeds. Mature individuals are removed from the wild and bark harvesting is also taking places causing population decline (Bosenberg 2009; Williamson et al. 2016).

Bosenberg, J.D. 2009. Encephalartos senticosus Vorster. National Assessment: Red List of South African Plants version 2020.1. 

CITES trade statistics derived from the CITES Trade Database, UNEP World Conservation Monitoring Centre, Cambridge, UK.

Williamson, J., Maurin, O., Shiba, S.N.S., Van der Bank, H., Pfab, M., Pilusa, M., Kabongo, R.M. and Van der Bank, M., 2016. Exposing the illegal trade in cycad species (Cycadophyta: Encephalartos) at two traditional medicine markets in South Africa using DNA barcoding. Genome, 59(9), pp.771-781.

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

Research shows that cycads are generally long-lived, have slow growth rates, produce low numbers of offspring and have infrequent recruitment (Golding & Hurter 2003, Donaldson 2003, Cousins & Witkowski 2017).Viable seed production in Encephalartos populations tends to decline with decreasing population size (Cousins & Witkowksi 2017). . A small remaining population with existing threat including exploitation (Bosenberg 2009), places the persistence of this species at risk whereby recruitment and recovery may be poor.

Bosenberg, J.D. 2009. Encephalartos senticosus Vorster. National Assessment: Red List of South African Plants version 2020.1. 

Cousins, S.R. and Witkowski, E.T.F., 2017. African cycad ecology, ethnobotany and conservation: a synthesis. The Botanical Review83(2), pp.152-194.

Donaldson, J.S. 2003. Cycads. Status survey and conservation action plan. IUCN/SSC Cycad Specialist Group, Gland, Switzerland; Cambridge, UK.

Golding, J.S. and Hurter, P.J.H., 2003. A Red List account of Africa's cycads and implications of considering life-history and threats. Biodiversity & Conservation12(3), pp.507-528.