APPENDIX 4 Indigenous Species Research Country Reports *

* No reports available from Swaziland and Uganda

PROMISING INDIGENOUS SPECIES IN ETHIOPIA

by Ms.H.Ibrahim

The principal habit-forms of the natural vegetation are well in accordance with the altitude and temperature. The lowlands are characterized by steppes, savannahs and woodlands while the highlands are occupied by forests which change in the higher mountains again to woodlands, savannahs and steppes.

The majority of the remaining forests are located in the south and western parts of the country. The vegetation types can be summarized as:

1. Coniferous
2. Montane mixed broadleaved/coniferous
3. Montane broadleaved
4. Lowland broadleaved

More than 86 species are found in Ethiopia which are used for timber. Among these species, 15 are widely exploited. There are also multipurpose species which are useful for fuelwood, charcoal, gum arabic and fodder.

The Forestry Research Service planted some indigenous species in 1975 and growth rate data are given in Appendix 1. Provenance trials were undertaken for Cordia africana and Hagenia abyssinica.

For major species, a summarized description follows on silvicultural characteristics, usage and nursery practices.

Acacia albida

This is a thorny species up to 18m in height and 1m in diameter and it grows where the annual rainfall is 300 - 500mm. It makes its best growth on sandy or silty soils. It is often seen in cultivated fields where it is grown for shade and to improve the soil. It comes into leaf at the end of the rainy season and remains green during the hot dry season.This peculiar habit makes it extremely valuable as a shade tree and producer of fodder for livestock in the dry period.

Acacia senegal

A thorny shrub or tree 3 - 5m tall with deep penetrating and wide spreading roots; it grows on poor soil, rocky hills and sand tracts, but is also found on black cotton soils.

It produces gum arabic which is used in medicine, the manufacture of chewing gum, and in the textile industry. The leaves are collected for fodder.

Albizia gummifera

A deciduous tree attaining a height of 35-40m, it grows in humid low highland forests at altitudes of 1600-2200m. It regenerates easily from seed. There are about 12 000 seeds/kg. Seeds are soaked in warm water till cool and germinate in 7-14 days. Seedlings reach plantable size in 4-5 months. The wood is suitable for boxes, crates, utility furniture and joinery. The tree is a principal shade tree for coffee plantations in south and south-western Ethiopia.

Aningeria adolfi-fredric

A tree attaining a height of 45-50m and a breast height diameter of 2-4m, the bole is heavily buttressed for 6-12m. It is found in wet montane forests at altitudes of 1600-2400m. Seeds are collected from the forest floor. Usually the seeds are attacked by insects and must be sown immediately. Seeds germinate in 4-5 days and seedlings reach plantable size in 8-9 months. The wood is useful for general carpentry and construction.

Cordia africana

This is the most widely used timber tree in Ethiopia and is a fast-growing deciduous species attaining heights of 30m in closed stands but much less and with crooked boles in the open. About 2 500 - 4 500 seed/kg are produced. The seed germinates within 21 days, the seedlings reaching plantable size between 5-7 months. The wood is used for furniture, plywood/veneer, boxes and for shade.

Ekebergia capensis

This is a deciduous species reaching heights of 30m, occasionally higher, and found in the upper and lower highland forests between 1 600 and 2 600 m.a.s.l. Seeds are small (35 000 - 40 000/kg) and are sown in pots in the nursery. Seeds germinate slowly and seedlings reach plantable size in 9-10 months. The wood is suitable for general carpentry.

Hagenia abyssinica

This species reaches 20m in height with a round or umbrella-shaped crown. It is found in semi-humid and humid mountain areas between 2 400 and 3 000 m.a.s.l. on well-drained soils.

Seeds are small (450 000-500 000/kg) and germinate within 14-30 days. Seedlings reach plantable size in 7-8 months.

The wood is used for furniture, interior joinery, light duty flooring and veneer.

Juniperus procera

This is the principal utility timber in Ethiopia, an evergreen tree, reported to reach 50m with a straight but sharply tapered bole. It grows on sand clays but also appears tolerant of widely varying soils. It is a slow growing tree with a rotation age of 60-80 years. Seeds are small (40 000-50 000/kg) and germinate very slowly. Seedlings reach plantable size in 12-16 months and require shade in the nursery. The wood is used for furniture, joinery, fence posts and transmission poles. The adaptability of this tree to less favourable site conditions at higher altitudes and the value of its timber justify its cultivation in spite of slow growth.

Olea africana

The species sometimes attains heights of 18m but 10m is average. It is common at altitudes between 15 000 to 25 000m and prefers well-drained sandy loams.

The tree produces about 7 000 seeds/kg. Germination capacity is very low. Seedlings reach plantable size within 12 months.

Podocarpus gracilior

This is an evergreen, dioecious species, attaining a height of 45m with a straight and cylindrical bole. It is dominant in semi-humid highland-forests between 1 700 and 2 200m on deep, fertile, well-drained soils.

The species produces about 2 100 seeds/kg but only 70 viable seeds/kg. Seeds germinate very slowly. Seedlings reach plantable size within 12-14 months.

It is a high quality softwood used for internal joinery, furniture and veneer panels. When treated with preservatives, it may also be used for outdoor construction.

Pygeum africanum

This species attains heights of 25-35m with a cylindrical, straight hole. It is found in humid and semi-humid highland forests above 1 800M and with a rainfall in excess of 1 000mm. It grows on fertile, sandy loams.

It grows slowly with a rotation age of 60-80 years. There are 3 000-5 000 seeds/kg which germinate slowly. Seedlings reach plantable size in 9-12 months. The timber is used for lorry bodies, railway trucks, bridge decking, heavy construction timber, coarse furniture and veneer. The leaves are a source of domestic fodder.

Appendix I

     Site Description

INDIGENOUS SPECIES OF KENYA

by P. Oballa and D. K.Musya

Extensive areas of Kenya's indigenous forests have been exploited over the last 50 years for sawn-timber and other forest products such as charcoal. As a result, many species such as Podocarpus spp., Juniperus procera, and Vitex keniensis have been severely depleted and could be completely lost by the end of the century. Little importance was attached to the planting of these valuable species, mainly on account of their slow rate of growth. However, exotic species have failed to replace indigenous timber in places where high quality is needed for furniture and interior furnishings. If Kenya is to earn more foreign exchange from forest products, these indigenous species must not only be conserved but be improved and grown side by side with the exotics.

Promising species for planting

The indigenous species planted can be grouped into three categories: those planted for their valuable timber; multipurpose species for agroforestry, and those planted as ornamentals. Timber species include Afzelia quanzensis, Chlorophora excelsa, Fagaropsis angolensis, Cordia abyssinica, Prunus africana, Vitex keniensis, Ocotea usambarensis, Juniperus procera and Podocarpus spp.

Vitex keniensis is widely planted on the eastern slopes of Mt. Kenya. Collection of seeds is from single trees or small natural groves. Germination is good and fairly uniform after 4 weeks. The species is grown in a rotation of 40-45 years. The timber works easily and polishes well and is used for furniture and panelling.

Chlorophora excelsa grows well in lowland rain forests and in wet regions of the coast. It prefers deep, fertile Moist loams and avoids acid soils. Seeds germinate well between 16-20 days and maintain viability up to 9 months. Seedlings are liable to gall infestation from mvule gall fly (Phytolyma lata) until they have reached heights of 5m. The timber matures at the age of 60-80 years. The species is highly valued for furniture, panelling and domestic flooring, boats and wharf timber.

Ocotea usamberensis. This species produces seeds about every ten years and in the forest it suckers. It is distributed in the montane forests of south and east Mt. Kenya, on the eastern slopes of the Aberdare Ranges and Taita Hills. Germination of the seeds is sporadic often taking 2-3 months. The trees mature in 60-75 years and frequently have heart rot. Due to difficulties in seed supply, the species can be raised by lifting natural root-suckers which are produced near the stumps of felled trees. The timber is valuable for furniture, panelling, flooring and heavy construction work.

Other important timber species being raised in plantations are: Podocarpus milanjanus, P. gracilior and Juniperus procera. These thrive in montane coniferous forests above 2 200m. Podocarpus spp. seed well but germination is sporadic, taking 1-6 months. They may also be grown using wildings, and mature in 75 years. These have been the standard building and general joinery wood of East Africa. It is odourless and nonresinous and is the accepted standard boxwood for packing of foodstuffs.

Regeneration experiments of valuable hardwoods of Kakamega forest has been going on for sometime and results indicate that some species (Maesopsis eminii, Croton megalocarpus, Olea welwitschii, Prunus africana and Markhamia platycalyx) can be profitably grown under the "Shamba" system. After felling the trees, young seedlings are taken care of by the shamba tenders and, at the same time, they bury more seeds which germinate. Cultivation of agricultural crops continues until the canopy closes. Pruning and thinning of the stand by the shamba owners is not permitted.

More indigenous species are being recognized for multipurpose use and have been included in experimental plots for agroforestry. These include Acacia albida, A.tortilis, A.xanthophloea, Balanites aegyptiaca, Acacia senegal and Tamarindus indica. These woody components of agroforestry systems are important for nitrogen fixation, produce dry season fodder and compete minimally with agricultural crops. In addition, species such as Acacia arabica is valued for tannin and gum arabic, and Tamarindus indica is planted for edible fruits. Sesbania sesban is important for firewood in swampy areas.

A Euphorbia project for the production of liquid fuel and charcoal briquets from Euphorbia tirucalli has started in Baringo District. Euphorbia is xerophytic and can produce excellent fuelwood in dry areas.

A number of indigenous species are grown as ornamentals and with increasing urbanization more will be planted. Ornamentals include Terminalia spp., Calodendron capense, Acacia xanthophloea, Ficus spp., Spathodia nilotica, Warbugia ugandensis and several Euphorbia spp.

The need to conserve the existing flora is a challenge to research-workers. Data must be collected on distribution, seed production, germination, tests and methods of vegetative propagation.

INDIGENOUS SPECIES RESEARCH IN MALAWI

by B. M. Chamba and E. Kananji

Indigenous species of Malawi are numerous but produce very insubstantial timber. Their main uses to date are to prevent soil erosion, flooding and maintain catchment areas. However, they do provide fuelwood and poles for domestic uses.

Indigenous species trials in arboretum form started in the late 1940's and early 1950's (Nkaonja 1982). A few species with valuable timber properties such as Burtt-davya nyasica, Chlorophora excelsa, Khaya nyasica, Parkia folicoldea, Pterocarpus angolensis, P.stolzii and Widdringtonia nodiflora were planted without any form of experimental design to permit meaningful statistical comparison.

The high demand of fuelwood and poles and the dwindling of forest resources prompted a sudden resurgence of interest in the 1970's in looking for fast-growing species. The Department of Forestry, with financial support from IDRC of Canada, embarked upon a rural fuelwood and polewood research project in September, 1978 and the indigenous species Acacia albida, A.pylacantha and Albizia versicolor were included in the trials. The choice of these species was based on their inherent multipurpose values for fodder, soil improvement and fuelwood.

This paper discusses the silviculture of some of the arboretum trial species and 1978 indigenous fuelwood and polewood trial species.

'Arboretum' trial species

Burtt-davya nyasica

This species occurs sporadically on alluvial grey-brown soils of the rift valley plains in southern Malawi.

The species produces mature fleshy fruit in abundance in April and May at the end of the rainy season. The species performance, in terms of growth, form and branching habit, is good. The timber is of high quality and used for structural construction.

Chlorophora excelsa

This occurs as a riverine species in small numbers bordering evergreen forests.

Establishment has been more successful from stump shoots than from root suckers. The use of seed has given high losses, particularly after pricking out into tubes (Nkaonja, 1982). In order to reduce losses, shade has to be provided at the nursery site.

In Malawi, there has been no report of gall-bug, (Phytolyma) which causes damage to C.excelsa. Interplanting C.excelsa with Terminalia combretum seems to reduce the propensity for insects to breed on C.excelsa, however this hypothesis needs to be tested. C.excelsa ia susceptible to fire and is only suitable for enrichment planting where complete fire protection is ensured.

The timber is hard and durable and used for cabinet work, building materials, canoes and boat construction.

Khaya nyasica

This is found along stream banks and moist areas of lower mountains and plateaus.

It is established easily from seed and has been planted in both single species plots and in mixtures with other species.

It is resistant to termite attack but is very susceptible to short-boxer attack (Hysipyla spp) which causes dieback and multiple leaders.

The timber has been used Largely for furniture, cabinet work, framing and panelling.

Parkia folicoidea

This species occurs in forests along rives throughout the country but not in large numbers.

The timber is easily worked and is used for mortars, poles, firewood. The yellow sticky pulp around the black seeds is edible and the whole fruit is good fodder for domestic stock.

Pterocarpus angolensis

This occurs in several types of indigenous woodland in Malawi as scattered individual trees.

Establishment of P.angolensis can be achieved from seed and germination is usually very high. Collection is done in September and October and the seed requires pre-treatment before sowing to a depth of 15-20mm with light watering. The seedling may show annual dieback during the dry season and this may happen for a period of 8 to 12 years. Consequently, establishment from 'truncheons' or stem cuttings is preferred to seedlings although survival is usually low. A moderate compaction of the soil around the truncheons appeals to improve the chance of survival.

The species is fire tolerant, a characteristic which makes it important for enrichment planting in areas where fire cannot be excluded completely.

It is used for quality furniture, joinery, boat building and other construction.

Widdringtonia nodiflora

This is an indigenous conifer which is found naturally on Mount Mulanje at altitudes over 1 500 m.a.s.l.

It has been established successfully from seed but grows more slowly than various exotic species. Interplanting of Mulanje cedar with pines has been carried out and 10 years after planting W.nodiflora was one half the height of Pinus patula and three-quarters the height of P.elliottii. Burning of seed on the ground also induces excellent germination and seedling growth is quite vigorous.

The species is highly resistant to fire damage and attacks by termites, borers and fungi.

It is used for various construction material.

1979 species trials

Acacia albida

This species occurs throughout the country, mainly below 600 m.a.s.l. in woodlands, savannas and along streams, often in pure stands where the water table is high.

It has been established successfully from seed and requires pre-treatment before sowing. It is a slow-growing species and exhibits dieback for some years until a deep tap-root develops. Because of its tendency to dieback during establishment, fire is not much of a hazard. The larvae of the butterfly, Aphnalus hutchinsoni, feed on the wood causing gum to exude from the bark.

The wood is used for handles, pestles, mortars and canoes. The fruit is valuable for livestock food.

Acacia pylacantha

This occurs in savannas and woodlands at low and medium altitudes in moist areas.

Establishment from seed has been quite successful and the seed requires pre-treatment before sowing. It is a fast-growing species. Moth caterpillars (Gynamisa maia) eat the leaves whereas butterfly caterpillars (Aphnaeus hutchinsoni) feed on the sap-wood. (Kitchin and Pullinger, 1982).

It yields a good gum exudate used for confectionery. The wood is used for building materials and tool handles. The root exudates are used for snake bite treatment and as part treatment for gonorrhea.

Albizia versicolor

The range of this species is widespread, from low to fairly high altitudes in woodlands and savannas.

It has been established from seed but growth is very slow.

The timber is used for doors, furniture, drums and mortars. Soap can be made from the roots. The pods, if eaten when young by stock or game are poisonous.

Table 1. Growth performance of some of the species mentioned.

REMARKS

From the preceeding discussion and Table 1, Burtt-davya nyasica, Chlorophora excelsa and Khaya nyasica show some potential, however these species required a lot of water. Research should be carried out to include provenance trials and examine silvicultural techniques (espacement,fertilizer application and thinning regimes) in order to improve their economy.

Pterocarpus angolensis, Acacia albida and A.pylacantha could be established from cuttings, but the cost of rooting hormones could be a constraint.

Although exotic species such as pines and eucalypts are fastgrowing, a good number of indigenous species have their merits, medicinal values, soil improvement, fodder for stock, which may not be substituted by exotics. Research on indigenous species in Malawi, like other African countries, is lagging behind in favour of exotic species.

REFERENCES

Kitchin, A.M. and Pullinger, J.S. 1982. Trees of Malawi, Blantyre Print and Publishing, Blantyre.

Nkaonja, R.W.S. 1982. The silviculture of indigenous and exotic forest trees other than pines and eucalypts - Malawi S. Afr. For. J. 121: 28-37