Taxonomy
Scientific Name
Aloe simii Pole-Evans
Higher Classification
Monocotyledons
Family
ASPHODELACEAE
National Status
Status and Criteria
Endangered B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v); C2a(i)
Assessment Date
2018/11/19
Assessor(s)
D. McKenzie, L. von Staden & H. Mtshali
Justification
Aloe simii has a restricted range, with an extent of occurrence (EOO) of 181-322 km², and an area of occupancy (AOO) of 20-24 km². This formerly common species now persists on a few isolated fragments around White River and Nelspruit, and is now locally extinct around Sabie due to historical habitat loss to timber plantations. The remaining population is small, consisting of 200-550 mature individuals, and is severely fragmented. The largest remaining subpopulation has only 115 mature individuals. It continues to decline due to ongoing habitat loss and degradation.
Distribution
Endemism
South African endemic
Provincial distribution
Mpumalanga
Range
This species is endemic to a small area in the transition area between the Mpumalanga Lowveld and Escarpment, where it occurs from Sabie southwards to White River and around Nelspruit.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Long Tom Pass Montane Grassland, Legogote Sour Bushveld, Northern Escarpment Quartzite Sourveld, Northern Escarpment Dolomite Grassland
Description
It occurs along drainage lines and in wetlands in open woodland and grassland, 600-1100 m.
Threats
Aloe simii has suffered extensive historical habitat loss, with at least 70% now irreversibly modified. Around Sabie and to the north of White River, it is now locally extinct due to habitat loss to timber plantations. Between White River and Nelspruit it is threatened by habitat loss to urban and agricultural expansion. The largest remaining subpopulation is likely to be entirely lost if a planned road construction project is to go ahead. Remaining subpopulations all occur on small, isolated fragments, where they are threatened by competition from alien invasive plants, inappropriate fire management, and disruption of water flow dynamics of seep ecosystems due to surrounding developments and plantations.
Population

Aloe simii is a localized habitat specialist that is declining due to ongoing habitat loss and degradation. Six subpopulations known through historical records are now locally extinct due to habitat loss. Recent field observations recorded four remaining subpopulations. All four are small and occur on isolated grassland remnants, with the largest subpopulation consisting of 115 plants. The population size is estimated to be between 200 and 550 mature individuals, and is considered severely fragmented. Intact habitat remains at a fifth locality, where the species was last recorded in the 1980s, and the persistence of the species at this site is uncertain. Based on 70% habitat loss and loss of 50-60% of subpopulations, a population reduction of 50-70% is suspected to have occurred since the 1940s. This species' generation length is not known, but it is likely that it may be within three generations, as Aloe species with similar habits tend to be slow-growing and long-lived.


Population trend
Decreasing
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Aloe simii Pole-EvansCR B2ab(ii,iii,iv,v)Raimondo et al. (2009)
Aloe simii Pole-EvansEN B1B2bVictor (2002)
Aloe simii Pole-EvansVulnerable Hilton-Taylor (1996)
Aloe simii Pole-EvansRare Hall et al. (1980)
Bibliography

Glen, H.F. and Hardy, D.S. 2000. Aloaceae (First part): Aloe. In: G. Germishuizen (ed). Flora of Southern Africa 5 Part 1, Fascicle 1:1-159. National Botanical Institute, Pretoria.


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.


Reynolds, G.W. 1969. The Aloes of South Africa. A.A. Balkema, Cape Town.


Smith, G.F., Steyn, E.M.A., Victor, J.E., Crouch, N.R., Golding, J.S. and Hilton-Taylor, C. 2000. Aloaceae: The conservation status of Aloe in South Africa: an updated synopsis. Bothalia 30(2):206-211.


Van Wyk, B.-E. and Smith, G.F. 2014. Guide to the Aloes of South Africa. (Third ed.). Briza Publications, 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
McKenzie, D., von Staden, L. & Mtshali, H. 2018. Aloe simii Pole-Evans. National Assessment: Red List of South African Plants version 2020.1. Accessed on 2020/08/10

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Distribution map

© D.R. McKenzie


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