Linear-leaf Sugarbush

Taxonomy
Scientific Name
Protea decurrens E.Phillips
Higher Classification
Dicotyledons
Family
PROTEACEAE
Common Names
Linear-leaf Sugarbush (e)
National Status
Status and Criteria
Near Threatened A2c+3c; B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v)
Assessment Date
2019/09/30
Assessor(s)
A.G. Rebelo, H. Mtshali & L. von Staden
Justification
Protea decurrens has a limited distribution range, with an extent of occurrence (EOO) of 8083 km², and area of occupancy (AOO) of 180-184 km². A population reduction of 21-27%, inferred from the recent rate of habitat loss, is projected to be met in 2049 over a period of three generations for this short-lived reseeder (15-20 years), which include two generations in the past and one generation projected in into the future. More than 10 locations are known, and the population continues to decline due to ongoing habitat loss to agriculture, and degradation by alien plant invasion, overgrazing and too frequent fire. Unexplained population declines have also been noted in some subpopulations.
Distribution
Endemism
South African endemic
Provincial distribution
Western Cape
Range
This species is endemic to the Western Cape, where it occurs from Shaw's Pass to the Langeberg Mountains.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Mossel Bay Shale Renosterveld, Ruens Silcrete Renosterveld, Greyton Shale Fynbos, Potberg Ferricrete Fynbos, Elim Ferricrete Fynbos, Swellendam Silcrete Fynbos
Description
It occurs in arid silcrete or ferricrete gravels at the fynbos-renosterveld ecotone, at 150-700 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 rodents.
Threats
Much of the lowlands of the Langeberg Mountains around Garcia's Pass have been planted with timber plantations, and the species' preferred habitat is targeted for wheat cultivation. There has been slight expansion of wheat cultivation and timber plantations in Riversdale, Swellendam and Shaw's Pass. About 61% of the habitat is irreversibly modified, and continues to decline, and if recent rate loss is projected into the future, could reach 21-27% in three generations, as the species is short-lived. Other threats noted during the field surveys include habitat degradation due to too frequent burning for grazing before plants set seed, overgrazing by livestock, and spread of alien invasive Hakea and wattle species. Unexplained population declines have also been noted in some subpopulations.
Population

This species is probably more common in suitable habitat than currently known. It is known from 25 fragmented subpopulations, and only two are protected. Although it has a limited distribution range, the population is estimated to be large. It has declined in the past due to habitat loss, and it continues to decline due to habitat degradation over most of its range.


Population trend
Decreasing
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Protea decurrens E.PhillipsEN B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v)Raimondo et al. (2009)
Protea decurrens E.PhillipsVulnerable Hilton-Taylor (1996)
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.


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.


Vlok, J. and Schutte-Vlok, A.L. 2010. Plants of the Klein Karoo. Umdaus Press, Hatfield.


Citation
Rebelo, A.G., Mtshali, H. & von Staden, L. 2019. Protea decurrens E.Phillips. National Assessment: Red List of South African Plants version 2020.1. Accessed on 2020/10/28

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Distribution map

© J.H. Vlok/A.L. Schutte-Vlok

© J.H. Vlok/A.L. Schutte-Vlok


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