TROPICAL SECONDARY FOREST MANAGEMENT IN AFRICA:
Ghana Country Paper
Mr M. O. Abebrese
P. O. Box MB434
4th Third Avenue Ridge
WORKSHOP ON TROPICAL SECONDARY FOREST MANAGEMENT IN AFRICA:
In collaboration with ICRAF and CIFOR
Nairobi, Kenya, 9-13 December 2002
Tropical forest ecosystems are diverse in terms of flora and fauna. This diversity is maintained by the disturbance-recovery regime of these forests because species have become adapted to the disturbances in different degrees. The different disturbance-recovery processes need to be maintained in order to maintain the biodiversity. The human disturbances (frequency, area, intensity) need to be in line with the natural disturbance-recovery processes to prevent irreversible change. Even slash-and-burn could be considered as a natural process because of its long association with forests, but the current rate of disturbance, and size and permanence of it, has made this a very undesirable process.
A secondary forest is the type of vegetation that results after the natural high forest vegetation has been disturbed and nature intervenes in an attempt to restore the vegetation to its original status.
Various factors account for the destruction of the original vegetation leading to the formation of secondary forest vegetation. In all cases human intervention is blamed for such destruction.
The area of Ghana is approximately 23.9 million ha and the population is about 18.4 million (2000 National Population Census). About 57 per cent of the total land is devoted to agriculture.
Ghana has two main kinds of vegetation. Tropical high forest occupies the southern portion and the savanna the northern and southeastern portion of Ghana. There are various formations their subdivisions were defined by UNESCO in 1973. Taxonomically the two are very distinct and very few plants occur naturally in both kinds of vegetations. A few of the trees, which can be found in both vegetation zones, are Afzelia africana and Diospyros mespilliformis. Leptaspis cochleata and Olyra latifolia are some of the grasses found in the high forest but not in the savanna. The forest-savanna transition zone is wide enough in many places to be recognized as a separate vegetation type (White 1983).
The savanna covers about 65.53 per cent of the total area of Ghana and tropical high forest covers about 82,000 km2 (34 per cent of the total land area of Ghana). This translates to approximately 0.5 per cent of the world's forests.
The country is categorized into unreserved forests and government gazetted forest reserves. There are 266 gazetted forest reserves with a total area of 1.22 million ha and 200 of these are located in the high forest zone (1.6 million ha). Forest and wildlife reserves occupy 18,000 km2 or 22 per cent of the forest zone of Ghana. Unreserved close canopy forest covers an area of 0.4 million ha.
Timber is currently being harvested from production areas, which constitute about 45 per cent of the total area within forest reserves. The remaining 55 per cent of the forest areas are designated as protection, conversion and research areas in conformity to Ghana's policy for environmental conservation.
At the beginning of the twentieth century Ghana had a total of about 8.6 million ha forested area, both inside and outside government gazetted lands. Currently forests outside forest reserve land have almost disappeared, leaving only the government gazetted forest reserves. It is estimated that the area of forested land left is about 1.6 million ha.
The rate of forest clearing outside forest reserves is such that intact forests have virtually disappeared except within forest reserves and in small patches of sacred groves near villages. The proportion of forests outside forest reserves declined from 20 per cent in 1955 to 5 per cent in 1972 (Forestry Department Annual Reports 1952 - 1972). Deforestation has been quite rapid between the periods 1950 and 1987. Nearly 75 per cent of the original forested land has been cleared by 1987. This translates to a deforestation rate of 0.84 per cent of the total high forest area (684 km2) per annum. That of the entire country is estimated to be 650 km2 per annum and that for the high forest zone of Ghana is currently estimated to be 220 km2 per annum. The decreasing rate is an indication that small areas of forests outside the gazetted forest reserves are conserved. Areas with poor stocking levels of economic trees are being converted into plantations. There are about 70,000 ha of plantations in Ghana with about 59,000 ha sited in the high forest zone. The countryside of the unreserved, three quarters of the forest zone is now a patchwork of man-influenced secondary type of vegetation.
The main crops cultivated in the forest zone are cocoa and oil palm. Other annuals cropped include plantain, cocoyam, yam and cereals (e.g. maize). In all cases the forest is cleared before the cropping is done. Agriculture (cocoa) is the main foreign exchange earner after mining.
Timber is harvested for export and local use. Nearly 1 per cent of the total value of timber is harvested annually to ensure sustainability. Annual timber exports earn the country about U$170 million and accounts for 18 per cent of exports and 5 - 6 per cent of the Gross Domestic Product (GDP). Currently timber ranks fourth in foreign exchange earnings. The timber industry employs about 10,000 people. Many rural dwellers depend on the natural forests for their livelihood through the extraction of Non Timber Forest Produce (NTFPs) (Falconer, 1992).
A few large isolated trees may be left when forests are cleared for food crop farming. These trees are usually burnt when fire is used to clear the brushwood and they may eventually die and disintegrate. After a few years the farm is abandoned to enable the land to rejuvenate under a fallow system. Coppice from cut trees together with tall herbaceous plants or sub-shrubby weeds such as Solanum species, various Marantaceae (e.g.Marantochloa leucantha and Thanmatococcus dariellii), Asteraceae such as Melanthera scandens, Aspilia africana and Chromolaena odorata, and grasses such as Setana spp, Panicum maximum, Panicum laxum and Paspalum spp invade the place and constitute the main vegetation. Two stages of regrowth develop, i.e. the "Forb regrowth" as described above, followed by thicket with abundant woody chimbers such as Adenia.
The timber industry in Ghana has for a long time been depending on the resources of the natural tropical forest for the supply of wood. The annual wood requirement is estimated at about 3.5 million m³.
The extent of forest disturbance increases with logging intensity. Increases in disturbances increase also from logging bays, skidding trails and hauling roads. Timber exploitation changes the structure and composition of the forest (Hawthorne 1989). The commercial extraction of trees (usually 70 cm diameter and above, and 45 m high) opens up wide gaps both in the canopy and on the ground. The felling of one mature tree destroyed 200 m2 and 300 m2 of vegetation cover (Owusu-Bi 1989). Studies at the Forest Research Institute of Ghana indicates that the extraction of one mature tree disturbs, on average, a ground area of between 345 m² and 600 m², depending on the size and shape of the tree (Dei-Amoah, 1993), crown size and the forest type. Such gaps created are later invaded by herbaceous species such as Chromolaena odorata, followed by other light loving trees such as Musauga cercropoides and Trema guineensis. The resultant vegetation eventually assumes a secondary forest status. Where the logging intensity is high the entire forest is put under convalescence (a recovery phase).
Post fire secondary forest is conservatively estimated to cover around 500,000 ha in the watersheds of streams and rivers in the drier zones of the high forest. They are mostly part of the drier forests, the dry semi-deciduous forest in the transition zone between the high forest and savanna. The land in such areas is level to fairly undulating. The incidence of bushfires is a major social problem. They always threaten the vegetation if attempts are not made to protect this from bushfires.
Traditional farming practices, which employ the use of fire, cause annual bushfires that sweep through these forests and destroy the original forest vegetation. They occur after logging for timber has opened up gaps leading to the invasion of some grass species and Chromolaena odorata. The resulting secondary forest is poorly stocked in terms of trees. Most of the young plants are destroyed by the bushfires. Lianas and thickets are very common in such forests.
Mining is currently the major foreign exchange earner for Ghana. It contributes about 36 per cent of the foreign exchange earnings followed by cocoa (35 per cent), tourism (12 per cent) and timber (10.4 per cent). Mining activities are most often limited to slopes of highlands and in the valleys. They may also occur close to major rivers and streams. The mining sector is currently invaded by illegal gold and diamond miners (popularly called "galamsey" miners). These are individuals who use simple tools such as the pick axe, hoes and shovels. The use of the simple tools does not permit them to undertake deep mining. They thus resort to the destructive surface mining, which destroys trees and vegetation of the high forest.
The increase in demand for minerals has also led to the proliferation of many mining companies who have been carrying out surface mining instead of deep mining. Mining exploration and prospecting are now being carried out even in government gazetted forest reserves which were not previously mined. Surface mining destroys the vegetation of the natural tropical high forest and lead to the formation of a secondary forest devoid of big trees.
Some of the big mining companies have started rehabilitating the areas where surface mining has been carried out. This is on a relatively small scale and is estimated to cover about 150 000 ha of land in the forest zone.
Secondary forests play a very important role in the lives of the communities that are located close to these forests. They provide an array of fruits and nuts, which are required as food for the rural people. A number of products, including non-timber forest produce, are obtained from such forests (Falconer, 1992). Many light loving tree seeds germinate with the opening of the canopy and thus the forest floor, and take their place in the secondary forests.
Many animals obtain their food from such forests, especially rodents, ruminants like the antelopes, birds, and reptiles. The rural dwellers to a large extent derive their source of protein from these animals that come to dwell in the secondary forest for shelter. Bush meat (from wild animals) constitutes a substantial proportion of the protein requirements of most rural dwellers in this part of the world. The bush meat sector employs about 300,000 hunters at the local level. Annually they produce 220,000 to 380,000 metric tons of bush meat for domestic consumption, valued at about US$350 million.
Apart from these benefits, rural people who live far from health centers, depend on the medicinal plants, which have become available as a result of the invasion of other herbaceous plants. The value of animals and plant products from the forests used in traditional medicine and cultural practices is estimated at US$13 million.
Other benefits include firewood, fencing poles and rafters, which they obtain from the regrowth of cut trees and other regeneration. Loss of revenue from timber harvesting is a major economic problem to both landowners and the government.
The management of secondary forests has not been given due attention in current management practices in Ghana. At least 110 out of the 266 gazetted forest reserves with an estimated area of about 8 million ha are in the form of secondary forest. Such areas have been designated as convalescence or recovery areas. All activities in such logged or degraded areas in forest reserves are suspended to allow them to regenerate naturally. Fire protection is being carried out to prevent fire from further destroying the forests.
In some areas green belts of trees that are resistant to fire damage, are being planted as a means to check invasion of bushfires into the forests. Long felling cycles of forty years and above have been set for these areas before logging activity could commence. This is to assist in the regeneration of the forest, as done in some selected forest reserves. In the mined areas the major mining companies are under obligation to rehabilitate such areas to restore the vegetation. The rural farmer, after cultivating secondary forest land for some time, leaves it to fallow and regenerate naturally. They make no conscious effort to manage these areas.
Current knowledge on the ecological, silvicultural and environmental characteristics of secondary forests is very limited. No conscious studies have been carried out.
Traditional ownership of land is either by an individual or a group of people (Ollenu, 1992). Five land ownership types are described in Ghana:
a) State land refers to land that the government has compulsorily acquired under the State Lands Act 1962, Act 125. Such land is acquired in the interest of the public.
b) Vested land is vested in the state under the Administration of State Lands Act 1962, Act 123. The state acts as the trustee for the relevant stool.
c) Stool land is vested in the relevant stool on behalf of the community, as represented by the Chief or the Traditional ruler or any in a fiduciary capacity for his people. Members of the land holding group have usufruct rights and are equivalent to a free hold. In a practical sense such land belongs to members of the land holding group and their interests are secure, inheritable and generally alienable. The alienation of such land by the stool or family requires the consent of the holder of this interest.
d) Family land is vested in a family whose head represents the family.
e) Privately owned land has a free hold interest and can be purchased outright by an individual or group of persons. This type of land invariably reverts back to become a family land should the owner die intestate.
According to Kasanga (1988), the term land tenure refers to the various laws, rules and obligations that govern the holding and/or ownership rights and interest in land. Generally the land tenure system of a particular area depends greatly on the traditional political organization within that particular community in Ghana. Any land which gets restored to the secondary forest status automatically belongs to the owner of the land. If it is an abandoned farm the land belongs to whoever was farming there previously. In a forest reserve however, such secondary forests are owned by the stools, which own the land. In other words, a change in status of the forest does not necessarily alter the ownership.
Of late, traditional authorities in Ghana who own such lands have been agitating that the government should consider seriously the involvement of the traditional rulers and for that matter the local people in what ever decision is taken in terms of the management of these areas. Mining areas outside gazetted forest reserves, rehabilitated by the mining companies, are given back to the communities who own the land to farm on.
Four main types of secondary forests in Ghana have been described based upon the process through which the secondary forest originated. These are the post logging secondary forest, post fire secondary forest, post shifting cultivation secondary forest and the post mining secondary forests.
In the past, researchers and forest managers were not much concerned with the management of secondary forests, which now dominate the landscape of Ghana with the loss of most of the natural tropical forests.
Current scientific knowledge of these types is quite superficial. Little is known about their ecology, silvicultural characteristics, environmental characteristics as well as their values. Total area covered by these types of secondary forests are currently estimated since there have not been any such studies. The scientific community and for that matter forest managers have not carried out any detailed study of the various types of secondary forest with a view to documenting them.
The tropical high forest in Ghana is dwindling fast. There is therefore a need to take a proper look at the secondary forests, which are now taking the place of the fast dwindling high forest vegetation. Secondary forests should become a focus of high priority in Ghana government policy.
Management practices currently being carried out in the high forest should equally be applied to the secondary forests.
Research focus in secondary forest, for immediate attention, should include their status in terms of area coverage, and use value for rural communities. There is a need for integrated studies into their environmental and silvicultural characteristics and management, and the socio-economic role they play in the lives of the people.
1. Dei-Amoah, C. 1993. Assessment of damage to residual stock in felling gaps in tropical high forest of Ghana. Case study: Asukese and Afram Headwaters Forest Reserve. 58 pp.
2. Falconer, J. 1992. Non Timber Forest Products in Ghana.
3. Hall, J. B. and Swaine, M. B. 1981. Distribution and Ecology of Vascular plants in Tropical Rainforest. Forest Vegetation in Ghana. 383 pp.
4. Hawthorne, W. D. 1989. The flora and vegetation of Ghana's forests. Ghana Forest Inventory Project. Proceedings of a seminar. J. Wong (Ed.). Accra. 29h - 30th March 1989.
5. Kasanga, K. R. 2002 - Paper delivered to the Regional House of Chiefs in Kumasi, Ghana.
6. Ollenu, J. 1962 - Traditional Customary Practices in Ghana.
7. Owusu-Bi, K. 1989. Environment development and vulnerability problems and prospects for environmental development in Ghana. Seminar paper. 2nd biennial SPRING Forum, U.S.T. Kumasi, April 1989.
8. White, F. 1983. The vegetation of Africa : A descriptive memoir to accompany the UNESCO/AETFAT/UNSO vegetation map of Africa. Natural Resources Research 20, UNESCO, Paris. 356 pp.