The African Pencil Tree
This interview was conducted by Pencils for Africa Assistant Editor and team member, Lucia, with Oxford University palaeocoelogist Dr. Elinor Breman in the year 2013.
What is a palaeocoelogist?
The Oxford Dictionary definition of palaeoecology (or paleoecology State side) is ‘the ecology of fossil animals and plants’ and a palaeoecologist is someone who studies these.
For me, however, a palaeoecologist is a time-travelling detective!
You get to explore the past and piece together the puzzle as records from different fossils come together to give you the bigger picture. For instance studying fossil pollen, as I have, can help you see what plants used to grow in a region, and how these changed over time. You then start to question what caused the changes and look to other fossils to help you find out, for example, looking at fossil charcoal will help you understand changes in fire regimes which can have a big impact on vegetation.
Why did you choose to get into this type of work?
Since I was at school I have been interested in tropical forests – the stories of their discoveries (for those in the western world) by early explorers, their abundance of animal and plant life, and the fact that they were endangered. For some time I studied and worked on the ecology of rainforests, and I even got to spend time living in a couple! I began to see that while it is important to understand how these forests work today, in our lifetimes, it is impossible to fully appreciate their dynamics without working on timescales more relevant to their lifespan. The majority of long term ecological studies last around 10 years, some have been going for 50 years or more.
Trees can live for 100s of years.
Only by looking further into the past can we come to a greater appreciation of the forces that govern forest dynamics, be they climate, fire, soil type, Man, or a combination of these and other factors. I am also interested in the management and conservation of ecosystems. The natural world that we see around us today has been formed in response to actions and events in the past.
By investigating these legacies we can better determine how an ecosystem and the species within it might respond to future change, and thus prepare management and conservation plans that are suited to their long-term needs. So I chose this type of work because I wanted to know more, and to improve my understanding of these remarkable systems. It has since opened windows for me on many different ecosystems around the world, including grasslands, savannas, forests.
Can you kindly tell us about the African Pencil Tree?
The African Pencil Tree (Juniperus procera) is a cedar (an evergreen tree) that grows in mountainous regions and often forms dense stands in montane forest, sometimes with other tree species.
It can grow to be 50 m tall (that’s almost as tall as Nelson’s column in Trafalgar Square, London), but is normally 30-35 m tall (stack 7-8 London red double-decker buses on top of each other). It would take an APT about 200 years to reach its maximum height, and it may live for another 300-700 years. The African Pencil Tree cannot regenerate in closed forest – that is, in order for new trees to grow there must be a disturbance event which creates a gap or opening in the forest, usual fire in the case of Juniperus procera, or other trees will take its place.
As well as being a beautiful tree in its own right, it is also a very useful tree. The African Pencil Tree is not just valued for making pencils, although it is exceptionally good at this. Its wood can be used for fire wood, for fencing, posts and poles, for construction and for making furniture. Hollow trees can be used as beehives, the bark and leaves have medicinal properties and the cedar oil distilled from sawdust can be used to make perfumes!
Can this tree grow in other places?
The African Pencil Tree is native to East Africa and the southern Arabian Peninsula. While its native range is large, individual populations tend to be small and threatened. It can grow outside this area, and has been planted in South Africa, India and Australia. As well as growing in natural forests, it is used in plantations and planted as ornamental species, to mark boundaries or give shade.
Why do people want to log these trees?
The wood of the African Pencil Tree is resistant to termites and fungi which makes it a good candidate for building your home from. It also burns well, and is, therefore, used as fire wood. In much of its range (e.g. Ethiopia) Juniperus procera is one of the most valuable timber trees, and will be selectively chosen for logging in preference to other species of lower commercial value. In addition to commercial fuel wood and timber exploitation grazing pressure and agricultural expansion also threatening forest persistence by promoting habitat degradation and loss.
Can another tree that is not endangered take the place of the African Pencil Tree?
Other trees can take the place of the African Pencil Tree for timber and fuel wood production, but as this species is so highly valued they tend to do so only once this tree has already been removed from an area by logging. An alternative is to create plantations for timber fuel wood in areas where natural forest containing Juniperus procera are found to reduce pressure on these native forests.
Such plantations can be of African Pencil Trees, and indeed it is preferable to use these as there is often resistance among local populations to use exotic species such as Eucalyptus which are seen as being inferior in quality to the APT.
In terms of pencil production, the export of Juniperus procera for the manufacture of pencils has ceased (at least from Ethiopia). A number of different species are in use, these include: Incense Cedar (Calocedrus Decurrens); Basswood/Linden wood/Lime wood (Tilia); Jelutong and Pulai which grow in Southeast Asian countries; Eastern White Pine and White Fir. There may be others, but these were the ones I found listed! In terms of its place in native forest, there is no alternative.
Are people in Africa supporting your aspirations to save the African Pencil Tree?
Many steps are being taken to help conserve the APT.
In addition to plantations mentioned above fuel efficient stoves have been introduced in many areas to reduce the amount of fuel wood required by local populations for cooking.
Improving pasture in areas with high grazing pressure is another possibility to help preserve forests of APTs. Much open forest pasture in Eastern Africa is overrun with thorny scrub, and if this can be removed then the pressure on closed forest would be reduced, and regeneration of the APT would not be hindered by grazing and browsing. In some areas native forest of APT is too degraded to conserve, but even here there is still hope through habitat restoration.
The following references are the sources Dr. Breman used for the above interview:
Borghesio, Luca; Fabio Giannetti, Kariuki Ndang’ang’a, Anteneh Shimelis (2004) The present conservation status of Juniperus forests in the South Ethiopian Endemic Bird Area. African Journal of Ecology 42, 137–143.
Bussmann, Rainer W. (2001) Succession and Regeneration Patterns of East African Mountain Forests. A Review. Systematics and Geographies of Plants, Vol. 71, No. 2, Plant Systematics and Phytogeography for the Understanding of African Biodiversity pp. 959-974
Orwa C, Mutua A, Kindt R, Jamnadass R, Simons A (2009) Agroforestree Database: a tree reference and selection guide. Version 4.0 http://www.worldagroforestry.org/treedb2/AFTPDFS/Juniperus_procera.pdf
Pohjonen, V. and Pukkala, T. (1992) Juniperus procera Hocht. ex. Endl. In Ethiopian forestry. Forest Ecology and Management, 49: 75 – 85.