Clanwilliam cedar (Widdringtonia cedarbergensis)

Description

Clanwilliam cedar fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Clanwilliam cedar description

This majestic tree belongs to a genus of trees known as cypress pines ⁽³⁾, tall and straight they dominate the landscape in a similar way to cypresses ⁽²⁾. The evergreen foliage is needle-shaped and compact ⁽²⁾. Both male and female cones appear on the same tree, male cones are small and appear at the end of the twigs in the autumn ⁽⁴⁾. Female cones are much larger with four thick, warty scales and take almost 3 years to ripen; the seeds are large and wingless ⁽⁴⁾.

Size

Height: up to 25 metres ⁽²⁾

Clanwilliam cedar biology

Clanwilliam cedars are extremely long-lived; ring counts have shown some specimens to be over 1,000 years old ⁽⁷⁾, and it takes around 30 years before an individual will bear a significant crop of seeds 4). In the rocky mountainous area where they are found there is very little rainfall and these cedars must put down extremely long roots to be able to reach the deep groundwater sources ⁽⁷⁾. These trees have a complex relationship with wild fires which periodically sweep through the region; severe fires are extremely damaging, killing many mature trees, but fires are needed in order to remove vegetation and litter (which otherwise inhibits young seedling growth) and to encourage seed germination ⁽⁴⁾.

Clanwilliam cedar range

Found only within the mountain range from which these trees gain their specific name: the Cederberg Mountains of the southwestern Cape in South Africa ⁽⁵⁾. Historical records suggest that large forests of these trees extended across much of the mountain range but fires and past over-exploitation have reduced the species to just 5 remaining populations ⁽¹⁾.

Clanwilliam cedar habitat

The Cederberg Mountains are now dominated by fire-prone 'fynbos', or fine bush vegetation ⁽⁵⁾, which mainly consists of small leaved, low-growing evergreen shrubs ⁽⁶⁾. Clanwilliam cedars are particularly associated with rocky ridges or outcrops at around 1,300 metres above sea level ⁽⁷⁾.

Clanwilliam cedar status

Classified as Endangered (EN - A1cd) on the IUCN Red List 2002 ⁽¹⁾.

Clanwilliam cedar threats

At the time of European settlement of South Africa the Clanwilliam cedar became massively logged in order to produce furniture, telegraph poles and other structures ⁽⁸⁾. Vast tracts of the ancient forest have been lost. Today, high-intensity fires represent the biggest threat to survival and groves of dead sliver trees, ravaged by fire, stand out starkly against the landscape ⁽⁵⁾. In early 2002, large bush fires destroyed around 200 hectares of a cedar plantation ⁽⁸⁾.

Clanwilliam cedar conservation

Logging of the Clanwilliam cedar was banned at the turn of the 20th Century but under various pressures such as fire, the population has not shown any signs of recovery ⁽⁵⁾. A concerted conservation programme to save this ancient giant is now in place, and a 5,252-hectare area has been set aside as a Cedar Reserve ⁽⁵⁾. Within the reserve, fires are managed and controlled in order to prevent high-intensity summer fires from sweeping through the area. Seedlings are also grown in order to be replanted, and thus help the struggling population to recover. It is hoped that focussing on such a charismatic species will also benefit other members of this unique South African habitat ⁽⁵⁾.

Authentication

Authenticated (20/3/03) by Dr Aljos Farjon, Royal Botanic Gardens, Kew.
http://www.rbgkew.org.uk

References

1. IUCN Red List (October, 2002) www.redlist.org
2. Eliovson, S. (1973) Wildflowers of Southern Africa. Macmillan, Johannesburg.
3. Smith College Botanical Gardens (October, 2002) http://www.smith.edu/garden/Academics/acadwiddring.html
4. Manders, P.T., Botha, S.A., Bond, W.J., and Meadows, M.E. (1990) The Enigmatic Clanwilliam Cedar. Veld & Flora, March: 8 - 11.
5. Mustart, P. (1993) What is the Cederberg without the cedar? Veld & Flora, December: 114 - 117.
6. CEMEX, IUCN (2001) The Red Book: the extinction crisis face to face. Agrupación Sierra Madre, Mexico City.
7. South African Museum (October, 2002) http://www.museums.org.za/sam/muse/9909.htm
8. Cape Nature Conservation (October, 2002) http://www.capenature.org.za/index.php?fArticleId=352