African pencil cedar (Juniperus procera)
|Also known as:||East African cedarwood|
|Size||Height: up to 45 m (2)|
Trunk diameter: up to 3 m (2)
The African pencil cedar is classified as Near Threatened (NT) on the IUCN Red List (1).
The African pencil cedar (Juniperus procera), the tallest of all juniper species in the world (2), acquired its name from its extensive use in the manufacturing of pencils (2). The trunk is straight and sharply tapered, covered with bark varying in colour from pale brown to reddish brown (3). Young African pencil cedars have needle-like leaves, one to two centimetres long, and as the plant ages the foliage gradually changes to the scale-like adult leaves, which are light-green or yellowish-green and only up to six millimetres long (3) (4). Male African pencil cedars bear numerous, tiny male cones at the ends of branches. These greenish to orangey-brown structures are composed of scales, each containing two to three pollen sacs. Female plants bear the female cones; reddish-brown to blue-black, berry-like structures made of fleshy scales, each one containing a single ovule (3).
The African pencil cedar has a wide distribution, ranging from the Arabian Penisula, through East Africa, to Zimbabwe. However, whilst widespread, many populations of the African pencil cedar are extremely small and threatened (5).
The African pencil cedar is found in mountainous areas and highlands (6), on rocky ground (5). In Africa, it occurs at altitudes between 1,050 and 3,600 metres, but is most common between 1,800 and 2,700 metres (6),
The evergreen African pencil cedar is dioecious (7), meaning that the male and female reproductive structures are borne on separate plants. Pollen, from the tiny cones on the male plants, is carried by the wind to the waxy, berry-like cones of the female plants (7). Fertilised by pollen, the ovules within the female cones develop into brown seeds. The African pencil cedar is believed to produce seeds only every several years (3).
While the export of the African pencil cedar for the manufacture of pencils has now ceased (2), its termite- and fungi-resistant timber continues to be popular for a great many purposes; local home construction and other carpentry, fuelwood, and for export (2) (5). This exploitation, in addition to expanding agriculture, browsing by animals such as buffalo and elephants, and the increase in plantations of fast-growing exotic species, is causing populations of African pencil cedar to decline (5). In Ethiopia, for example, indigenous forests have been decimated over the past 100 years with forests cleared for crops and grazing, and trees harvested for fuelwood (2). Habitat destruction has been so great that in southern Ethiopia it is unlikely that forests of Juniperus species will persist for long (8).
Efforts have been made to ensure the continued survival of this valuable tree; in the late 1970s the African pencil cedar became part of a plantation establishment program of the State Forest Department of Ethiopia, and in the late 1980s, trees were planted at a rate of a few hundred hectares per year (2). The aim of these plantations is to produce the necessary fuelwood and timber for the Ethiopian population, in order to decrease the pressure on remaining natural forests (2). However, to re-establish forests of African pencil cedar in East Africa, it is believed that natural regeneration should be promoted, including protecting young trees from grazing animals (2).
Authenticated (10/11/08) by Richard Spjut, World Botanical Associates, Bakersfield CA, USA.
- Dioecious: male and female reproductive organs are borne on separate plants.
- Ovule: a structure within the female reproductive organ of a plant that contains an egg cell and when fertilized by pollen, develops into a seed.
IUCN Red List (April, 2011)
- Pohjonen, V. and Pukkala, T. (1992) Juniperus procera Hocht. ex. Endl. In Ethiopian forestry. Forest Ecology and Management, 49: 75 - 85.
World Agroforestry Centre: Agroforestree Database (December, 2007)
The Gymnosperm Database (December, 2007)
- Oldfield, S., Lusty, C. and MacKinven, A. (1998) The World List of Threatened Trees. World Conservation Press, Cambridge, UK.
- Farjon, A. (2005) A monograph of Cupressaceae and Sciadopitys. Royal Botanic Gardens, Kew.
- Mamo, N., Mihretu, M., Fekadu, M., Tigabu, M. and Teketay, D. (2006) Variation in seed and germination characteristics among Juniperus procera populations in Ethiopia. Forest Ecology and Management, 225: 320 - 327.
- Borghesio, L., Giannetti, F., Ndang’ang’a, K. and Shimelis, A. (2004) The present conservation status of Juniperus forests in the South Ethiopian Endemic Bird Area. African Journal of Ecology, 42(2): 137 - 143.