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Scientific Name | Leucadendron tradouwense I.Williams |
Higher Classification | Dicotyledons |
Family | PROTEACEAE |
Common Names | Tradouw Conebush (e) |
National Status |
Status and Criteria | Critically Endangered B1b(iii)c(ii,iv) |
Assessment Date | 2020/04/24 |
Assessor(s) | A.G. Rebelo, D. Raimondo & L. von Staden |
Justification | Leucadendron tradouwense is a highly restricted endemic species that has an extent of occurrence (EOO) and area of occupancy (AOO) of 40 km². There is ongoing degradation of habitat as a result of alien plant invasion, and too frequent or aseasonal fires. It is recorded from two subpopulations but over 95% of individuals occur in one subpopulation. All mature individuals are killed by fire, and recruitment takes place following burns. Fluctuations in subpopulations have been observed to occur in response to fire and thus extreme fluctuations in population size occurs for this species. It therefore qualifies as Critically Endangered under Criterion B. |
Distribution |
Endemism | South African endemic |
Provincial distribution | Western Cape |
Range | This species is endemic to the Langeberg Mountains in the vicinity of Tradouw Pass, in the Western Cape, South Africa. |
Habitat and Ecology |
Major system | Terrestrial |
Major habitats | South Langeberg Sandstone Fynbos, Swellendam Silcrete Fynbos |
Description | It occurs on steep, south-facing sandstone slopes, 160-180 m. Mature individuals are killed by fires, and only seeds survive. Seeds are released after ripening, and collected by rodents and stored in underground caches, where they are protected from fires. It is dioecious, with insect-pollinated male and female flowers occurring on separate plants. |
Threats |
| A total of 12% of this species habitat has been irreversibly transformed for planting of pasture in the past, habitat loss for pasture cultivation is no longer ongoing. The lower slopes of the Langeberg mountains are, however, badly infested with woody invasive alien species (Pinus and Acacia). It is apparent from satellite imagery checked in 2020 that the lower portions of the Grootvadersbos subpopulation are being encroached by invasive species. Invasive species are also a threat at Gats River Valley but there has been extensive alien clearing at this site between 2015 and 2020 so currently this pressure is reduced here. Ongoing invasive plant clearing efforts are required to ensure this species habitat is not degraded and these efforts are only occurring at the Gats River Valley subpopulation. Too-frequent fire and aseasonal fire also pose a significant threat. As this is a reseeding species with over 90% of individuals confined to one subpopulation fire related fluctuations are possible. Fluctuations of subpopulations size has already been observed to occur at the Gats River Valley subpopulation (see population description). Fires return intervals are predicted to shorten with increasing drought frequency as a result of climate change. |
Population |
It is known from two subpopulations that occur within 4.5 km of one another, the first subpopulation occurs at Grootvadersbos at Snelsetter, is large with between 1,000 and 10,000 individuals present but is predicted to be declining as a result of competition from invasive alien plant species. The second subpopulation occurs at Gats River Valley-Southey’s Arms and is a single stand occurring in an area of 100 m x 20 m, fewer than 100 plants are at this site, and extreme fluctuations have been observed over the past 30 years of monitoring. Between 1993 and 1996 there were only 2 plants but following a fire 50 and 100 plants were recorded in 2001. This site was monitored again in 2010 and appears stable but remains highly vulnerable to fire season and return interval.
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Population trend | Decreasing |
Conservation |
| Not currently conserved in any formally protected area. |
Notes |
| Leucadendron tradouwense is part of a group of closely related taxa related to L. tinctum, but sufficiently different to warrant a distinct status. |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | | Leucadendron tradouwense I.Williams | CR B1b(i,ii,iii,iv)c(iv) | Raimondo et al. (2009) | | Leucadendron tradouwense I.Williams | Vulnerable | Hilton-Taylor (1996) | | Leucadendron tradouwense I.Williams | Endangered | Hall et al. (1980) | |
Bibliography |
Goldblatt, P. and Manning, J.C. 2000. Cape Plants: A conspectus of the Cape Flora of South Africa. Strelitzia 9. National Botanical Institute, Cape Town.
Hall, A.V., De Winter, M., De Winter, B. and Van Oosterhout, S.A.M. 1980. Threatened plants of southern Africa. South African National Scienctific Programmes Report 45. CSIR, Pretoria.
Hilton-Taylor, C. 1996. Red data list of southern African plants. Strelitzia 4. South African National Botanical Institute, Pretoria.
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.
Rebelo, T. 2001. Sasol Proteas: A field guide to the proteas of southern Africa. (2nd ed.). Fernwood Press, Vlaeberg, Cape Town.
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Citation |
| Rebelo, A.G., Raimondo, D. & von Staden, L. 2020. Leucadendron tradouwense I.Williams. National Assessment: Red List of South African Plants version . Accessed on 2025/05/25 |
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