Large-leaf Sugarbush

Taxonomy
Scientific Name
Protea convexa E.Phillips
Higher Classification
Dicotyledons
Family
PROTEACEAE
Common Names
Large-leaf Sugarbush (e)
National Status
Status and Criteria
Vulnerable A4ac
Assessment Date
2020/07/29
Assessor(s)
A.G. Rebelo, D. Raimondo, N.A. Helme & A.L. Schutte-Vlok
Justification
Protea convexa is a habitat specialist from the arid mountains of the Cape Floral Region. It has an extent of occurrence (EOO) of 12 415 km² and an area of occupancy (AOO) of 188 km². It is known from 17 subpopulations from 12-15 locations. Two of the known locations are currently declining due to habitat loss to rooibos tea cultivation, and degradation by alien invasive plants. Too frequent fires are causing the population to decline in the eastern part of its range. The most severe threat facing this species is however climate change. Field observations indicate that it is susceptible to drought-related mortality and recruitment failure. Based on observations of population decline in the past 15-20 years and projecting these impacts forward for a further two generations (30-40 years) this species is suspected to experience a population decline of between 30 and 50% over a three generation period. It therefore qualifies for listing as Vulnerable under criterion A.
Distribution
Endemism
South African endemic
Provincial distribution
Western Cape
Range
This species has a narrow distribution in the Northern Cederberg, Witteberg and Klein Swartberg Mountains, in the Western Cape Province of South Africa.
Habitat and Ecology
Major system
Terrestrial
Major habitats
North Swartberg Sandstone Fynbos, Matjiesfontein Quartzite Fynbos, Swartruggens Quartzite Fynbos
Description
It occurs in arid, rocky kloofs, 1100-1500 m. Mature individuals are killed by fires, and only seeds survive. Wind-dispersed seeds are stored in fire-resistant inflorescences, and released after fires. It is pollinated by birds and insects.
Threats
A small proportion of this species' habitat has been lost to agriculture. Currently it is threatened by ongoing habitat loss to rooibos tea cultivation near Wuppertal. Field observations noted low presence of alien invasive plants and too frequent fires in Swartberg. Local extinctions can occur if fires repeatedly kill individuals before they reach reproductive maturity. Habitat loss to windfarms over most of its known range is a recent and future threat. Climate change and habitat loss modelling predicted that this species could decline by over 80% by 2025 (Bomhard et al. 2005), while but no such drastic population reductions have yet occurred, a number of drought-related mortality events followed by recruitment failure have been noted especially in the western portion of this species range suggesting that this species is indeed vulnerable to climate change impacts.
Population

There are 17 subpopulations known from 10 -15 locations. These are all restricted to a narrow habitat, very little of which is conserved. About 40% of the subpopulations have less than 200 mature individuals, and are naturally fragmented. A population decline of 30-50% is inferred from habitat loss and degradation witnessed over the past generation (15-20 years) and projected into the future for a further two generations (30-40 years).


Population trend
Decreasing
Conservation
Three subpopulations are conserved in the Anysberg Nature Reserve.
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Protea convexa E.PhillipsCR A3c+4cRaimondo et al. (2009)
Protea convexa E.PhillipsRare Hilton-Taylor (1996)
Protea convexa E.PhillipsRare Hall et al. (1980)
Bibliography

Bomhard, B., Richardson, D.M., Donaldson, J.S., Hughes, G.O., Midgley, G.F., Raimondo, D.C., Rebelo, A.G., Rouget, M. and Thuiller, W. 2005. Potential impacts of future land use and climate change on the Red List status of the Proteaceae in the Cape Floristic Region, South Africa. Global Change Biology 11(9):1452-1468.


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.


Citation
Rebelo, A.G., Raimondo, D., Helme, N.A. & Schutte-Vlok, A.L. 2020. Protea convexa E.Phillips. National Assessment: Red List of South African Plants version . Accessed on 2024/04/17

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Distribution map

© C. Paterson-Jones

© C. Paterson-Jones


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