| Application of biomass-energy technologies |
|I. Woodfuel production technologies|
Zimbabwe, situated in Southern Africa, has a total area of 391,000 square kilometres and its population in 1991 was estimated by Moyo et al (1991) to be around 10 million, with an average annual growth rate of 3.0 per cent. About 22 per cent of the population live in urban areas.
Makoni (1990) reported that woodfuel accounts for 85 per cent of household energy consumption and for about 40 per cent of all energy consumed in Zimbabwe. However, the supply of woodfuel is dwindling rapidly in particular in the communal land, consequently creating localized woodfuel scarcities.
Land use in Zimbabwe is divided into three main sectors, namely, communal land, commercial farms and urban areas. Production of woodfuel takes place in the first two sectors.
Communal lands constitute 42 per cent of the total land and is used by more than 60 per cent of the total population. Communal lands are located in semi-arid to arid areas with poor soils such as in the provinces of Masvingo, Matebeleland North, Matebeleland South and Midlands. As the land is communally owned, individual farmers can cultivate but not sell the land. Communal free- grazing is also practiced, which has contributed to serious overstocking. Scarcity of woodfuel in Zimbabwe is mainly confined to the communal lands, due to population pressure and poor soil fertility. Also, it is estimated that between 70,000 and 100,000 ha of woodlands are cleared for agricultural expansion annually (Moyo et al 1991).
Commercial farms constitute 43 per cent of the total land area They are located in the best fertile lands and their average size is about 2500 ha per farm. They are normally self-sufficient in energy supply including woodfuel.
The Government of Zimbabwe, like those of many other developing countries, has initiated tree-growing programmes for woodfuel and environmental protection.
1. The Zimbabwe Rural Afforestation Project
The initial main government effort in tree-growing for woodfuel and environmental protection in Zimbabwe was the Rural Afforestation Project, Phase one. It was implemented between 1983 and 1989 with a total budget of $Zim 17.4 million (about $US7.31 million) from the World Bank and executed by the Forestry Commission. The project had the following major components:
• Establishment of centralized nurseries for seedling production;
• Establishment of demonstration and trial woodlots;
• Establishment of woodlots in the communal lands;
• Establishment of block plantations in urban and rural areas.
Nurseries were successfully established and seedlings produced according to targets. However, costs were very high, when compared with those of NGOs and school nurseries.
Demonstration trial woodlots of 5 ha in size, were established close to most nurseries. The objective was to demonstrate to farmers the rotational practices of the species tried. However, farmers were not prepared to establish such woodlots or to practice fixed rotations.
Establishment of woodlots in communal land through participatory efforts was not successful either. Farmers were required to establish small woodlots of 750 trees (0.5 ha) each but most of them were keen to plant only a few trees on farmland and not to establish woodlots, partly due to land scarcity.
Establishment of block plantations also proved to be very expensive and as a result the target of establishing a total of 1400 ha was not attained.
Some of the basic weaknesses of the initial planning of the project were:
• It was based mainly on paid labour with little people's participation; Local knowledge on tree-growing and possible interventions for meeting rural and urban woodfuel needs were not considered in detail;
• The multiple use of tree products and people's needs were ignored, the project concentrating only on woodfuel;
• Central nurseries were expensive due to the need to construct supportive infrastructure, and the cost of distributing seedlings over long distances;
• Growing of indigenous species was ignored in favour of exotic species;
The whole project suffered from a rigid conception that was not sufficiently based on actual socio-economic situation of the target population.
According to Makoni (1990), the main constraints experienced in implementing the phase one were:
• Lack of an experienced workforce for implementing woodfuel programmes.
• Inadequate extension services to farmers;
• Land shortage for establishing woodlots in the communal lands;
• Grazing problems on woodlots and planted trees on farm lands;
• Lack of a knowledge of suitable tree species for the different ecological zones of the country.
Nevertheless, the experience gained from the project provided a better opportunity for implementing future projects more successfully.
Phase two of the project was initiated by encouraging the following: individual treeplanting on agroforestry principles; establishment of small local nurseries in villages or schools or by individual farmers; establishment of pilot schemes in forest and grazing management; consideration of local knowledge on tree growing, farmers' needs and growing of multi-purpose trees including indigenous species; and adoption of a multisectorial approach in planning and implementing the project.
2. Catalytic assistance from NGOs
NGOs in Zimbabwe have been active and instrumental in the development of afforestation activities in the rural areas. They provide materials for establishing individual nurseries and individual tree-growing on agroforestry principles, conduct courses, workshops and seminars on tree-growing, establish woodlots and provide management of natural woodlands. They also conduct research on indigenous species for woodfuel and identification of indigenous technical knowledge on tree growing and management of forests.
1. Analysis of the case studies 1. Introduction
The case studies show the existence of several common features and constraints related to woodfuel production. Several of these features are also common to the other biomassenergy technologies described in this report and are examined at the end of the report. Here, only features relevant to woodfuel-production technologies are examined.
2. Supply-side constraints
(a) Understanding the woodfuel problem
Lack of knowledge of the supply potential of woodfuel and the rate of its depletion is a major constraint. Without reliable data on the supply potential, it is difficult to understand the dynamics of the woodfuel-production process.
(b) Lack of knowledge of means to sustain woodfuel supply
Efforts to sustain woodfuel supply started in the mid-1970s. This task was given to foresters, but they had little experience on how to sustain tree crops in farmland and rangelands. The means for sustaining woodfuel supply are, therefore, only being developed through trial and error.
(c) Lack of knowledge of suitable specks
To meet the farmers' needs for growing trees, a wide range of species for the different ecological zones has to be tested and proven appropriate, before they are given to farmers to grow them on a wide scale. Unfortunately, knowledge on appropriate species is lacking, particularly for indigenous species, as past research efforts concentrated only on exotic species. Furthermore, research results of the few species studied are not yet widely disseminated which thus inhibits sharing of experiences and learning from models of best practices.
(d) Land-tenure problems
In many countries, land tenure is based on undefined traditional laws and rules. Management of woodlands under communal land tenure thus tends to be problematic, in particular where such efforts are not initiated by the local people themselves.
(e) Termites and drought attacks
In the arid and semi-arid ecological zones, drought and termites attacks on planted trees are a problem, particularly with exotic species. Termite- and drought-resistant species are, therefore, urgently needed.
(f) Shortage of seeds
Seeds of species appropriate for woodfuel and agroforestry are in short supply. In addition, many of the desired species have low seed viability and require special storage facilities. Seed collection and distribution centres for woodfuel species are not yet established, except for a few NGOs which are assisting in seed collection and distribution.
(g) Lack of knowledge on traditional methods of growing indigenous trees species
The main reason why foresters concentrate on exotic species is their lack of knowledge on how to grow most of the indigenous species. This is leading to a loss of genetic resources, and a risk of losing the planted trees in the event of a disease or insect epidermic.
(h) Lack of emphasis on management of natural forests
Tree growing in arid and semi-arid climatic zones is difficult. For these areas, effective management of the indigenous natural forests is a pre-requisite for sustaining woodfuel supply. This is lacking in most countries.
(i) Lack of harvesting and marketing plans for urban woodfuel plantations
In most cases, only establishment plans have been developed for urban woodfuel plantations. Harvesting and marketing plans are not yet developed. As a result, foresters experience problems in selling woodfuel from the few maturing urban plantations.
3. Demand-side constraints
The demand-side constraints refer to those factors which prevent people obtaining wood from supply sources. These are, mainly, inaccessibility, privatization, unaffordability and low security.
Natural forests and large-scale timber plantations, which could contribute to woodfuel production, are located far from many users' reach, in particular beyond their walking distance. Inaccessibility, therefore, limits the contribution of these potential woodfuel supply sources to the community.
Granting of land-tenure rights to individuals, in particular large-scale farmers, privatize large areas which were formerly the main sources of wood to surrounding villagers and landless people. In many cases, collection of woodfuel from private farms is prohibited and protected by law. It is therefore, not an uncommon phenomenon, to find under-utilized woodfuel resources in private farms, while the majority of the surrounding population experiences woodfuel scarcity.