by
R.D. Ayling 2 and A.C. Mubita 3
Zambia has a great variety of natural resources including forests and wildlife, which are vital to the continuing development of the country's economy. More than half of the country is wooded and 9.8% of the total surface area is protected forest. However, deforestation from the combined effects of clearance for agriculture, forest fires, logging, fuelwood collection and charcoal production for domestic use and tobacco curing, is increasing, especially around major urban centres.
A National Conservation Strategy, calling for the conservation and improved management of important genetic resources, was prepared for Zambia in the early 1980's. Already prior to the elaboration of the strategy, an important initiative in the area of conservation was undertaken by the Zambian Forest Department, with assistance from FAO. This was the establishment of two reserves (totalling some 36 ha) in the Sesheke Province, for the conservation of representative samples of Zambian teak forests in the country (Baikiaea plurijuga). Zambian tea or “mukusi”, as it is locally known, is a valuable tree for industrial purposes. The natural forest in which it occurs also contains a variety of other useful tree species, as well as several plants with medicinal value.
Past research into ways of stimulating natural regeneration was only moderately successful and indicated that natural regeneration alone was insufficient to sustain these ecosystems. Flowering and fruiting is erratic, seed dispersal poor, and seeds and seedlings are damaged by wild animals. Seedlings are also subjected to intense competition from colonizing shrubs of Acacia and Combretum species known as “mutemwa” (Piearce, 1986). Early investigations of artificial regeneration including propagation techniques, spacing trials and enrichment planting were promising and suggested that conditions could be developed to permit at least limited re-establishment by the species (Malaya, 1986).
The need to conserve and introduce wise management practices was a subject of an international conference in 1984 in Livingstone, Zambia (ZFD, 1986). As a follow-up to this conference, the Zambian Forestry Department's research branch approached Canada's International Development Research Centre (IDRC) 4 for assistance. The following research programme addresses the concerns of the Livingstone conference and the objectives of the World Conservation Strategy to preserve genetic diversity and sustain the utilization of species and ecosystems.
2 Senior Programme Officer, International Development Research Centre, Nairobi, Kenya.
OBJECTIVES OF THE RESEARCH PROGRAMME
The long-term objective of the project under the direction of the Zambia Forest Department, is to develop effective methods for the management and regeneration of the Zambezi teak forests.
Several specific objectives, which may be attainable or at least started during the life-span of this three-year project, are:
to establish and manage in situ genepool management units within productive forest areas;
to investigate both in situ and ex situ methods of artificial regeneration; and,
to promote national and regional efforts in sustained management of these ecosystems.
ACTIVITIES
The project started in late 1987 with a small workshop of interested parties to explain the proposed research. Gene conservation stands or genepool management units are to be identified and gazetted in 1988 in productive forests as Managed Resource Areas (MRAs) according to international guidelines (FAO, 1984). The cooperation and active support of local timber companies will be essential and several have already indicated their interest. The demarcation of these units will be made with the assistance of the local people to avoid potential land-use conflicts. The expected size of the MRAs should be between 10–50 ha to permit the establishment of paired plots, and will be a compromise between an ideal biological strategy and a strategy giving due emphasis to local socioeconomic needs. Paired plots will allow the comparison of manipulative treatments and strictly conserved portions. Management interventions will be carried out in sub-plots to favour the conservation and regeneration of the major tree species and could include controlled burning to reduce understorey weeds, the removal of diseased and insect-infested material, stand thinning at different intensities, and direct sowing and enrichment planting. One purpose of these MRAs is to eventually provide sources of seed of known origin and quality, and hence a buffer zone will be created around the MRAs to minimize contamination by pollen of non-local origin.
Management plans will be prepared for each MRA and will have the dual purpose of maintaining genetic variation while allowing for managed utilization by the rural communities, (firewood, minor forest produce and limited grazing by domestic animals).
Seed and/or vegetative materials, identified and documented by MRA source, will be used to raise seedlings for enrichment planting and for establishing ex situ conservation stands. Research on all major species of these ecosystems will be undertaken by the Forest Research Division of the Forestry Department with the assistance of the University of Zambia's Biology Department. Studies to encourage maximum root development in the nursery will include root pruning to induce laterals, shoot pruning to improve root: shoot ratios and the use of improved soil mixtures including polymers to enhance root systems. If successful, rooting of stemwood cuttings will aid the conservation of genetic material and will be used for ex situ clonal banks of specific genotypes.
Given adequate research management, technical and financial assistance, and international interest, the outputs from this project should include a series of registered in situ gene conservation stands under sound management to ensure sources of broad-based genetic material for breeding purposes and scientific study. Rural populations should also benefit from assured wood supplies and other non-wood forest products and services, as well as from continuous and regular employment.
It is hoped that the project will also serve as a model to other countries involved with forest genetic resource conservation and utilization (especially neighbouring countries in which Baikiaea plurijuga is indigenous).
For additional information, readers are requested to contact the authors of this article.
REFERENCES
FAO 1984 A Guide to In Situ Conservation of Genetic Resources of Tropical Woody Species. FAO, Rome. FGR/Misc/84/2. (196 pp.)
Malaya, F.M. 1986 A Review of Silvicultural Research in the Zambian Teak Forests. pp. 167–177. In “The Zambezi Teak Forests” (G.D. Piearce, ed.). Zambia Forest Department. (535 pp.)
Musokotwane, I.E.O. and S.F. Kufakwandi. 1986 The Importance of the Teak Forests in the Zambian Economy. pp. 375–383. In “The Zambezi Teak Forests” (G.D. Piearce, ed.). Zambia Forest Department. (535 pp.)
Piearce, G.D. 1986 How to Save the Zambezi Teak Forests. Unasylva 38(152): pp. 29–36.
ZFD 1986 “The Zambezi Teak Forests”. Proceedings of the First International Conference on the Teak Forests of Southern Africa, March 1984, Livingstone, Zambia. (G.D. Piearce, ed.). Zambia Forest Department. (535 pp.)
FAO 1985 In situ gene conservation stands: Malawe and Kataba Botanical Reserves. In: Report on the FAO/UNEP Project on the Conservation of Forest Genetic Resources, pp. 18–28. FAO, Rome. (171 pp.)
FAO 1988 In situ Conservation of Zambian Teak Forest. In: Plant Genetic Resources. Their Conservation in situ for Human Use, p. 9. FAO, Rome. (in press).
