|
Scientific Name | Conophytum swanepoelianum Rawé subsp. rubrolineatum (Rawé) S.A.Hammer |
Higher Classification | Dicotyledons |
Family | AIZOACEAE |
Synonyms | Conophytum rubrolineatum Rawé |
National Status |
Status and Criteria | Endangered A3c+4d |
Assessment Date | 2021/12/09 |
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 Western and Northern Cape provinces of South Africa with an extent of occurrence (EOO) of 367 km2 and area of occupancy (AOO) of 60 km2. The population is experiencing initial levels of decline due to the illegal 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. The continued threat of illegal collection is therefore regarded as very high for this particular taxon and a decline of more than 50% of the population is likely within the next three generations (90 years) due to this activity. Anthropogenic climate change is a major threat to this succulent. Modelling of climate change impacts is predicted to result in an average loss of 75% of suitable bio-climatic habitat by 2080 under likely CO2 emission scenarios (RCP 2.6). An overall population decline of between 70 and 75% of the population is thus suspected within the next three generations (90 years). It therefore qualifies as Endangered under criteria A3 and A4. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Northern Cape, Western Cape |
Range | This dwarf succulent is endemic to the Western and Northern Cape provinces of South Africa where it has a restricted geographic range. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | Doringrivier Quartzite Karoo, Nardouw Sandstone Fynbos, Bokkeveld Sandstone Fynbos |
Description | This succulent occurs in both the Fynbos and Succulent Karoo biomes. The plants primarily occupy, and sometimes completely fill, fine sandy-grit pans on weathered areas of table mountain sandstone.
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 |
| Plants have been subject to illegal collection of mature individuals for the international trade in ornamental succulents since 2019. As plants confiscated by the authorities in South Africa have only been identified to species level all the subspecies are treated the same here and are therefore believed to have been collected illegally. This taxon has been highly sought after by collectors and is highly likely to remain so in future. A population decline of 50-70% is suspected over three generations (90 years) as a result of this activity.
There is no decline in habitat quality for this taxon as inferred by changes in vegetation cover determined from changes in Enhanced Vegetation Index (EVI) between 1984 and 2018 using Landsat data (Venter et al. 2020), however anthropogenic climate change is a long-term threat to this succulent. 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 75% and 100% by 2080 for this taxon. Species in this genus have limited dispersal ability and migration to suitable habitats elsewhere is regarded as highly unlikely. |
Population |
This taxon is usually locally abundant. There are no formal estimates of population size but there are likely between 25,000 and 50,000 mature individuals. The population is experiencing initial levels of decline due to illegal collection for the ornamental succulent plant trade.
|
Population trend | Decreasing |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Conophytum swanepoelianum Rawé subsp. rubrolineatum (Rawé) S.A.Hammer | VU B1ab(v)+2ab(v) | 2020.1 | | Conophytum swanepoelianum Rawé subsp. rubrolineatum (Rawé) S.A.Hammer | Rare | 2017.1 | | Conophytum swanepoelianum Rawé subsp. rubrolineatum (Rawé) S.A.Hammer | 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.
Raimondo, D., von Staden, L., Foden, W., Victor, J.E., Helme, N.A., Turner, R.C., Kamundi, D.A. and Manyama, P.A. 2009. Red List of South African Plants. Strelitzia 25. South African National Biodiversity Institute, Pretoria.
|
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 swanepoelianum Rawé subsp. rubrolineatum (Rawé) S.A.Hammer. National Assessment: Red List of South African Plants version . Accessed on 2024/12/07 |
Comment on this assessment
