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Scientific Name | Conophytum marginatum Lavis subsp. marginatum |
Higher Classification | Dicotyledons |
Family | AIZOACEAE |
National Status |
Status and Criteria | Endangered A4cd |
Assessment Date | 2021/11/30 |
Assessor(s) | A.J. Young, P.G. Desmet, I. Ebrahim, D. Guo, A. Harrower, L. Jabar, L. Knoetze, C. Rodgerson, P.C.V. Van Wyk & N.N. Mhlongo |
Justification | This succulent is endemic to the Northern Cape province of South Africa with an extent of occurrence (EOO) of 297 km2 and area of occupancy (AOO) of 84 km2. The population is in decline due to illegal collection for the ornamental succulent plant trade, with collection likely to increase as there has been a dramatic increase in the number of species and volume of plants targeted since 2019. A decline of between 50 and 75% is suspected over the next three generations (90 years) as a result of the loss of mature individuals to illegal collection. Climate change is also impacting the population although there is uncertainty of the response given the expected resilience of this taxon. It therefore qualifies as Endangered under criterion A4. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Northern Cape |
Range | This succulent is endemic to the Northern Cape province of South Africa where it has a restricted geographic range. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Nama Karoo, Succulent Karoo |
Description | This succulent is primarily found in the Succulent Karoo biome (primarily the Richtersveld bioregion but also the Namaqualand Hardeveld bioregion) and extends into the Nama-Karoo biome. The plants occupy cracks and crevices on quartz. This taxon has a generation length of 30 years. It is expected to be sensitive to the impacts of climate change as it does not disperse and while adapted to arid conditions, is dependent on limited seasonal rainfall. Species in the genus are sensitive to long periods of drought. Drought related mortality has been observed for other closely related taxa within the genus. |
Threats |
| This taxon is currently threatened by illegal collection for the international trade in ornamental succulents. This is likely to increase in future as there has been a dramatic increase in the number of species and volume of plants targeted since 2019. As a result a population decline of 50-75% is suspected over three generations (90 years).
Anthropogenic climate change is a long-term threat to this succulent. Loss of vegetation cover has been observed across the geographic range occupied by this succulent via Landsat imagery between 1984 and 2018 indicating a decline in habitat quality. Climate models for the likely emission scenarios where emissions stay at present day levels (RCP 2.6) (Hausfather and Peters 2020) and worst case scenarios where emissions continue to increase during the 21st century (RCP 8.5) indicate that there will be a loss of suitable bioclimatic envelope of between 39% and 85% by 2080 for this taxon. However, as this taxon occurs in a very sheltered habitat it is expected to have a level of resilience to climate change and the expected population loss is reduced by 20% to 19%. Species in this genus have limited dispersal ability and migration to suitable habitats elsewhere is regarded as highly unlikely.
Grazing and trampling by livestock also presents a localised threat to some subpopulations. |
Population |
It is known from several subpopulations that are typically small in extent but where the plants may be locally abundant. There are no formal estimates of population size for this taxon but the number of mature individuals is probably between 25,000 and 75,000. The species is known to be in declined due to illegal collection to supply the international trade in ornamental succulents although confiscated plants have been identified to species level only. It is however extremely likely that this subspecies is declining due to illegal collection.
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Population trend | Decreasing |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Conophytum marginatum Lavis subsp. marginatum | Least Concern | Raimondo et al. (2009) | |
Bibliography |
Hammer, S. 2002. Dumpling and his wife: New view of the genus Conophytum. EAE Creative Colour, Norwich.
Hammer, S.A. 1993. The genus Conophytum: A conograph. Succulent Plant Publications, Pretoria.
Hausfather, Z. and Peters, G.P. 2020. Emissions - the 'business as usual' story is misleading. Nature 577(618-620).
Opel, M.R. 2004. The rediscovery of Crassula alcicornis. Haseltonia 10:38-40.
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Citation |
| Young, A.J., Desmet, P.G., Ebrahim, I., Guo, D., Harrower, A., Jabar, L., Knoetze, L., Rodgerson, C., Van Wyk, P.C.V. & Mhlongo, N.N. 2021. Conophytum marginatum Lavis subsp. marginatum. National Assessment: Red List of South African Plants version . Accessed on 2024/12/06 |
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