3.2 Assessment of Non-Timber Resources in Africa August B. Temu
Summary
The accuracy of inventory and monitoring of timber resources has benefitted from the technological advances in remote sensing, Geographical Information Systems (GIS) and data processing. This has not been true of non-timber resources, mainly due to their large diversity, small volume, and highly variable abundance and values across regions, cultures and seasons. Africa in particular, has not been able to plan for rational management of its forest resources, primarily due to the lack of reliable inventories.
Non-timber resources may be divided into two major categories; wood and non-wood products. For Africa, wood products include wildings, stakes, firewood, craft materials, canes and bamboo. Non-wood products can be categorized as plant products (e.g., fruits, leaves, nuts, roots, fibres), plant extractive ( e.g. gums, resins, latex), animal products ( e.g., honey, meat and others), water and intangibles.
This paper dwells on the inventory of non-timber plant products and extractive. It recommends generic product classification and description of parameters to be estimated and variables to be measured. Attention is drawn to the multiplicity of disciplines likely to be involved in inventory and monitoring processes.
The use of remote sensing and GIS technologies is proposed for the identification of niches for the various products. The accuracy of estimates will depend on the product and sampling methods/intensity used, but as a whole confidence limits are likely to be wide. As such, standard errors of estimates are likely to be set at a lower level than for timber inven
tories.
3.2.1 Introduction
The forests of Sub-Saharan African (SSA) offer a large diversity of tangible and intangible non-timber products. The economics, social and environmental value of the various products is yet to be determined, primarily due to the lack of precise information on their location and rate of change. The abundance of the products in local markets, especially in communities living near forest areas is a good indicator of their existence and uses. Figure 1 presents a very broad classification of the products. POULSEN (1982) divided non-wood products into the following categories: feed, fibres, food, drugs and chemicals. He emphasized traditional African values in the assessment of these products. In this treatise I will dwell only on products derived from plants.
The 1994 draft World Bank policy on forest support to SSA sets as a principle the integration of people, the private sector and appropriate levels of government in the management of forest resources {World Bank 1994). Such a noble goal will be meaningful if the needs of the communities are assessed and the potential of the forests to meet these needs evaluated. Unfortunately, neither of these has happened. In my view, there is a greater demand for non-timber than for timber products by local communities. This is especially so when fuelwood is considered as a non-timber product. Although the World Bank policy recognizes the need to devote more time and resources to inventory and monitoring of forests no specific mention is made of non-timber products.
"
Nontimber Products
I
"From Animals From Plants From the Ecosystem
._ Meat, Trophies ._ Fuelwood - Water
� Tourism ._ Food (nuts, fruits .. ) � Environ. Influences
._ Fodder
._ Extractives (gums ... )
._ Craft Materials
-
PharmaceuticalsFig. 1. Classification of Non-timber Products.
For Sub-Saharan Africa, the non-timber forest products are important for the following reasons:
1. over 90% of the population is rural, and in their day to day lives people interact with forest resources quite frequently. The products contribute significantly to their livelihood and to some cash income.
2. Dependency on rain-fed agriculture can be catastrophic in years of drought. Forests serve as special reserves for the provision of food and fodder.
3. The hitherto unexploited genetic potential of some forest plants may be depleted through un-organized and uncontrolled harvesting by local communities. In many cases, the ecosystems are quite fragile and very hard to regenerate.
4. Fuelwood is the only affordable source of energy for cooking, heating and curing cash crops such as tobacco and tea.
It is necessary to develop a system of inventorying and monitoring the non-timber resources, in order to facilitate their development and management.
3.2.2 State of the Art in Non-timber Inventories
In Sub-Saharan Africa, a few inventories and surveys have been made on specific non
timber products such as resins, gums, mushrooms, and certain fruits. Examples of such studies can be seen in Kenya, Ghana, South Africa, Sudan, Tanzania, Zambia and Zimbabwe. The surveys are highly localized (geographically} and have been carried out as
"single shot" activities, not followed up subsequently (WONG 1989). Use of the findings is quite limited. Many of the surveys were focused on a single plant/tree species and the multiplicity of its products. In Zambia, a very good survey of the edible mushrooms was done, but little further effort was made to develop the resource.
Some ideas on inventory and management of non-timber products have arisen at seminars and workshops, but few concrete actions have been taken (CIRAD-CTFT; 1991).
BOOTH and WILKENS (1988) produced a summary of information, processing and utilization of non-timber products from 27 tree and shrub species in arid zones of Africa.
An assessment of the production per tree or shrub or per unit area is also presented. Other aspects such as traditional extraction technologies and scope for the improvement of productivity are discussed. Yield figures were unreliable because they were based on too small samples.
In an elaborate book, ABBIW (1990) has characterized non timber products as including food and fodder, furnishings, fuel, tools and crafts, potions and medicines, poisons, tannin and dyes. This classification differs from that of POULSEN (1982). T EMU (1991) points out the product measurement and inventory design problems. He concludes that there is a need to develop methodologies for multi-product inventories of tropical mixed forests.
The International Centre for Research in Agroforestry (ICRAF} is doing a survey of some indigenous multi-purpose tree and shrub species. The objective is to identify them and enhance propagation of trees suitable for agroforestry technologies, and which could have additional benefits such as soil enrichment and the production of fruits or fodder. On the basis of survey results, fruit trees such as Parinari excelsa and Vangueria infaustra are being tested for propagation and productivity. Sesbania spp. are being tested for soil en
richment while a large range of species are being evaluated for fodder production.
A lot of work has been done on the chemistry of gums and resins from various species and on the quality of fodder. These two aspects dominate the literature on non-timber products in Africa. Very little is known of inventory aspects.
POULSEN (1982) recommended a comprehensive survey of non-timber products.
The forest inventory expert in SSA faces the following problems in the estimation of non-timber products:
• Poorly defined products, in terms of parameters to be estimated.
• Highly variable product distribution over space, time and culture.
• Uncertainty over the present and future value of the non-timber products.
• Shortage of expertise and resources committed to inventory and monitoring as a whole.
Growing population pressure on forest resources is likely to lead to the degradation of some of niches, and thus disappearance of some of the products. The impact will be felt most by the poorest of the poor as they are the major beneficiaries of the non-timber products.
From the technical viewpoint, modern technologies such as remote sensing and geo - graphic information systems have a role to play in such inventories. For the sustainable management of non-timber forest products in SSA, the following steps should be considered:
1. Synthesizing and summarizing the results of surveys and studies done on non-timber products so far.
2. Characterizing communities in terms of their need and demand for non-timber products. On the basis of this, the products can be classified by quality and socio
economic value.
3. Defining in generic terms, parameters to be estimated, and develop predictive variables or equations.
4. Planning and executing sequential inventories to cover all forest areas, with special emphasis on linking this with standard timber inventories to cut down field costs.
Involvement of the local communities and other relevant expertise is necessary.
5. Developing a database to enhance information sharing and updating.
3.2.3 Ideas on Inventory
Given the complexity of non-timber products and their distribution, one cannot expect to develop a single inexpensive inventory and monitoring method. One possibly useful strategy is to follow an ecological approach. If we assume that the probability of finding a given product in a forest depends on the ecological niche obtaining in the area, then we can classify the forest area according to ecological niches.
A lot of ground surveys, combined with aerial photography would be necessary to develop relationships between ecological niches and the types and quantities of non - timber products. Vegetation location, type, height and density may be used to describe the ecological niches. These variables are easy to assess from aerial photographs, thus reducing expensive ground surveys by the application of two phase sampling techniques.
There is one important feature to consider - seasonality. The quantities and quality of a number of products, such as mushrooms and fodder are dependent on the season of the year. Others such as fruits of some trees may be produced only once in several years.
Therefore the timing of remote sensing should be done very carefully to capture this variation.
We can then develop a two-way matrix of the available niches and quantity of a given product. (Table 1).
The question is how fine or coarse we can make the scale of ecological niches. Of course the finer, the better the precision, but most certainly costs will be a major factor to consider.
Table 1. Product Quantity by Ecological Niches.
Niches
Product Units 1 2 3
A A C
We can also project this in three dimensional way if data can be obtained on the trends
in the productivity of the niche (Figure 2). One major difficulty is that the products are expressed in different units of measurement, e.g. tonnes of dry biomass, litres of extractive, etc. Thus comparability among the products may not be easy.
The results of biophysical surveys need to be superimposed on socio-economic surveys.
This can be achieved by using geographical information systems (GIS). For instance, one can delineate the biophysical boundaries of a given product, then superimpose on the map, the economic boundaries for the harvesting transportation and use of the same product.
This would transform the inventory results to practical use by the local communities.
Inventory expertise will be needed from forestry, horticulture, pharmacy, ecology and social sciences ( culture, economics) and the indigenous knowledge from the local communities. It is crucial that the latter are part of the inventory and monitoring process, for the use and long term management of the products depend primarily on them.
Quality 100
80
60
----_
. ..:.__ _
---
-- .. ---··0 -+----.---.---T"""----.----.----�
1994 1995 1996 1997 1998 1999 2000
Fig. 2. Product Inventory and Monitoring
3.2.4 Conclusion
Product A - - - Product B Product C -- -- Product D - - - · Product E
The degradation of most of Africa's forests continues to take place despite the ban on export of tropical timbers. This is because the largely rural communities rely on forests for many products which have hitherto not received the attention of inventory experts. The unmonitored harvesting of these products, coupled with the conversion of forest areas to agricultural production threaten the survival of the local communities as both forest and agricultural land degrade to lower productivity levels.
Ignorance looms over the exact extent of the resources and their rate of change.
Investment into resource information management systems is given lowest priority by
national governments and donors. If this attitude is sustained, the future of forest resources in Africa remains unpredictable.
Finally, an inventory is useful if it can be used to improve management decision making.
Serious thought should be given to the way results can be used before major non-timber product inventories are undertaken.
The ideas shared in this paper generate more questions than answers. For instance, there is little help on the sampling designs and statistical protocols which will provide reliable product estimates. Nonetheless, the holistic approach is probably a useful way to begin unravelling the inventory problems.
3.2.5 References
ABBIW, D., 1990: Useful Plants in Ghana - West African uses of wild and cultivated plants.
Intermediate Technology Publications and Royal Botanic Gardens Kew. Short Run Press Exeter, England. 33 7 pp.
BOOTII, F.E. ; WICKENS, G.E ., 19 88: Non -timber uses of selected arid zone trees and shrubs in Africa. FAO Rome. FAO conservation guide No. 19: 1 76 pp.
CIRAD-CTFf., 1991: Wood and non-wood tree products in Sub-Saharan Africa (F). Proceedings of a Conference held at Montpellier, France, 10-14 Dec. 1990. 19 5- 2 14.
P OULSEN, G., 1 9 82: The non -wood products of African forests. Unasylva. 34, 1 57: 1 5- 2 1.
TEMU, A.B., 199 2: Multi-product inventory of tropical mixed forests: The Inventory agenda. In:
TEMU, A.B.; M ALIMBWI, R.E. (eds.): Proceedings of an international workshop at Arusha.
August 1 5-19, 1991. 1 2 5 pp.
WONG, J.L.G ., 19 89: Ghana forest inventory project. Proceedings of a Seminar 23-30 March 1990, Accra. ODA London UK. 101 pp.
World Bank, 1994: A strategy for the forest sector in Sub -Saharan Africa. (Draft document for discussions).
