Ontologia
Cycad

Cycad

Encephalartos whitelockiiP.J.H.Hurter

CRLR Monde (IUCN)
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Pays · région · aire protégée · écorégion · biome

Graphe en cours d’indexation

Calcul du tissu écologique de Encephalartos whitelockii.

Le graphe apparaîtra automatiquement dès que le calcul est terminé (rafraîchissement toutes les 5s).

Liste rouge IUCN

CR · En danger critiquecritères B1ab(iii,v)+2ab(iii,v)Décroissante
Évaluation complète
Évaluation
2024 · v3.1
Altitude
10001200 m
Profondeur
m
État de la populationExpert
The population size of Encephalartos whitelockii is estimated to be 8,000 mature individuals. Seedlings and small plants are absent from open habitats which may be as a result of too frequent fires, but under forest canopy, prolific regeneration occurs. The recorded sex ratio is 43% female to 57% male. The population has declined since 2008 initially due to the construction of a hydroelectric plant but also due to land invasions and clearing for cash crops.

Menaces identifiées(7 menaces classées CMP-IUCN)

  • 2_1_2
    Small-holder farming
    Rapid DeclinesMinority (<50%)Ongoing
  • 4_1
    Roads & railroads
    Negligible declinesMinority (<50%)Ongoing
  • 3_3
    Renewable energy
    Slow, Significant DeclinesMinority (<50%)Ongoing
  • 2_3_2
    Small-holder grazing, ranching or farming
    Ongoing
  • 5_2_1
    Intentional use (species is the target)
    Ongoing
  • 5_3_1
    Intentional use: (subsistence/small scale) [harvest]
    Ongoing
  • 7_1_1
    Increase in fire frequency/intensity
    Ongoing
Description complète des menacesExpert
Threats to the species include:
a) Construction of a small hydro electric power plant on the Mpanga River Falls:
i - construction of roads and camps in the cycad belt, causing soil erosion and deep gullys, reducing habitat quality
ii - reduction in population of mature and young individuals as they are knocked down by heavy machinery
iii - reduction in area of habitat owing to parts being occupied by weir (reservoir), water canal, and power house

It was reported that the actual area of cycads impacted by the construction is probably less than 5% of the total area inhabited by the cycads. (Luke and Luke 2010)

b) Local community activities:
i - reports of collection of seed and seedlings for commercial trade may impair the regeneration capacity of the cycad and thus lead to further reduction of its population
ii - cultivation on the slopes of the gorge and clearing of land for cash crops
iii - harvesting of the cycad leaves for building materials
iv - burning of some areas occupied by the cycad for stimulation of grazing pasture.

Habitats préférentiels (classification IUCN)

  • 1_6Forest - Subtropical/Tropical Moist Lowland
  • 2_1Savanna - Dry
  • 6Rocky areas (eg. inland cliffs, mountain peaks)
Mesures de conservation recommandéesExpert
This species is listed in Appendix I of the CITES Appendices. Only a very small part of the gorge falls within the Queen Elizabeth National Park, thus no more than 2% of the population occurs inside the park. Community sensitization has been done in the area but harmful community activities such as burning and cutting continue. Identification of further suitable sites for the formal protection of this species is needed. Long-term monitoring of the population will support the conservation of this species.
Actions de conservation (2)Expert
  • 1_1Site/area protection
  • 4_3Awareness & communications
Stress écologiques (13)Expert
  • 1_1Ecosystem conversion
  • 1_1Ecosystem conversion
  • 1_2Ecosystem degradation
  • 1_2Ecosystem degradation
  • 1_2Ecosystem degradation
  • 1_2Ecosystem degradation
  • 2_1Species mortality
  • 2_1Species mortality
  • 2_1Species mortality
  • 2_1Species mortality
  • 2_2Species disturbance
  • 2_3_6Skewed sex ratios
  • 2_3_8Other
Usage & commerce (2)Expert
  • 13Pets/display animals, horticulture
    internationalnational
  • 9Construction or structural materials
    subsistance
Priorités de recherche (4)Expert
  • 1_2Population size, distribution & trends
  • 1_3Life history & ecology
  • 1_6Actions
  • 3_1Population trends
Niche IUCN globaleExpert

Royaumes biogéographiques

Afrotropical

Systèmes (terrestre/eau douce/marin)

Terrestrial

Formes de croissance

CycadTree - large
Références bibliographiques (8)Expert
  1. IUCN. 2024. The IUCN Red List of Threatened Species. Version 2024-1. Available at: <a href="www.iucnredlist.org">www.iucnredlist.org</a>. (Accessed: 27 June 2024).
  2. Luke, Q. and Luke, T. 2010. Site Visit Report: Mpanga River Gorge, Uganda 21st and 22nd August 2010.
  3. Byaruhanga, A., Kalema, J. and Namara, A. 2008. The Impact of Dam Construction on the Biodiversity and Ecology of Mpanga River Gorge, Kamwenge District, Western Uganda.
  4. Whitelock, L.M. 2002. <i>The Cycads</i>. Timber Press, Portland, Oregon.
  5. Hurter, J. and Claassen, I. 1996. Focus on <i>Encephalartos whitelockii</i>. <i>Encephalartos</i> 48: 4-9.
  6. Donaldson, J.S. 1995. Understanding cycad life histories- an essential basis for conservation. In: Donaldson, J.S. (ed.), <i>Cycad Conservation in South Africa- Issues, actions and priorities</i>, pp. 8-13. Cycad Society of South Africa.
  7. Vorster, P. and Heibloem, P. 1995. <i>Encephalartos successibus</i> (Zamiaceae): a new species from Uganda. <i>South African Journal of Botany</i> 61(6): 347-351.
  8. Hurter, P.J.H. 1995. Two newly described cycads from Africa. <i>Phytologia</i> 78(6): 409-416.
Évaluateurs & contributeurs (3)Expert
assessor
Bösenberg, J.D.
contributor
Kalema, J.
evaluator
Donaldson, J.S.

Bösenberg, J.D. 2024. Encephalartos whitelockii. The IUCN Red List of Threatened Species 2024: e.T41928A51045938. Accessed on 05 May 2026.

Répartition mondiale (heatmap GBIF)Construction en cours

0 obs · 0 cellules
Construction par partitions temporelles GBIF0%

Source : GBIF — observations agrégées par hexagones 0.2° × 0.2° (~22km). Filtre qualité : précision coordonnée < 10 km. Coloration quantile (q50/70/90/99). Fond carte : OpenFreeMap · © OpenStreetMap.

Distribution mondiale

Calcul de la distribution GBIF· ~10–60 s

Phénologie

Calcul du calendrier d'apparition· ~5–30 s

Consulter sur les bases externes

Observations & statuts

Cartographie

Bibliographie

Note nomenclaturale & synonymesExpert

Note nomenclaturale

TAXREF v18 — INPN/MNHN

Synonymes (2)— redirigent vers cette page

  • Encephalartos successibusVorster
  • Encephalartos successivusVorster

Sources : Catalogue of Life Cross-References (synonymes) · TAXREF v18 INPN/MNHN (commentaires FR).