Richtersveld Aloe

Taxonomy
Scientific Name
Aloe pearsonii Schönland
Higher Classification
Monocotyledons
Family
ASPHODELACEAE
Common Names
Pearson's Aloe (e), Richtersveld Aloe (e)
National Status
Status and Criteria
Vulnerable A2ac; B1ab(iii,v)+2ab(iii,v)
Assessment Date
2015/05/09
Assessor(s)
P.C.V. Van Wyk & D. Raimondo
Justification
A range-restricted (National EOO 121 km²), and formerly locally abundant species that is estimated to have declined by at least 30% in South Africa over the past 10 years, due to dramatic increases in grazing pressure since 2006. It therefore qualifies for a Vulnerable National listing, but as more than 80% of this species' range falls within South Africa, its national status is not downgraded.
Distribution
Endemism
Not endemic to South Africa
Provincial distribution
Northern Cape
Range
Endemic to the Gariep Centre, occurring in the northern section of the Richtersveld and in mountains just north of the Orange River in southern Namibia.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Central Richtersveld Mountain Shrubland
Description
Steep, rocky, south- and southwest-facing slopes in arid shrubland, 300-1500 m.
Threats
Severe overstocking of livestock across the Richtersveld is causing ongoing degradation of this species' habitat. It is a spiny species that is not usually browsed, but overgrazing has reduced palatable species to such an extent that desperate livestock are now starting to browse this species, and many plants are dying as a result of the damage caused (P.C.V. van Wyk pers. obs.).
Population

The largest population is in the Helskloof, Richtersveld. This species was listed in 2009 as Least Concern based on the fact that subpopulations can be very large, consisting of thousands of individuals covering entire mountain slopes, and this species was formerly the dominant plant species in areas such as Helskloof and on the Vandersterrberg. Monitoring of certain areas within the Richtersveld over the past six years have noted rapid population decline, estimated to exceed 30% of the population. Decline has been most rapid over the past 10 years, after stocking rates increased dramatically since 2006. Recruitment is poor, and mortality of mature individuals is high.


Population trend
Decreasing
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Aloe pearsonii SchönlandVU A2ac; B1ab(iii,v)+2ab(iii,v)2015.1
Aloe pearsonii SchönlandLeast Concern Raimondo et al. (2009)
Aloe pearsonii SchönlandEN B1B2abceVictor (2002)
Aloe pearsonii SchönlandVulnerable Hilton-Taylor (1996)
Bibliography

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.


Victor, J.E. 2002. South Africa. In: J.S. Golding (ed), Southern African plant Red Data Lists. Southern African Botanical Diversity Network Report 14 (pp. 93-120), SABONET, Pretoria.


Citation
Van Wyk, P.C.V. & Raimondo, D. 2015. Aloe pearsonii Schönland. National Assessment: Red List of South African Plants version 2017.1. Accessed on 2018/11/18

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Distribution map


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