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DRYLAND FORESTRY AND AGROFORESTRY IN THE SUDAN: Results and current topics of Sudan-Finland research cooperation
by Olavi Luukkanen, Mohamed A. El Fadl and Abdalla Gaffar Mohamed
With a land area of 2.5 million km2, the Sudan is the largest country in Africa, although sparsely populated with only 25 million inhabitants. Most permanent settlement is concentrated in the vicinity of the Nile river system and in areas with more than 300 mm of annual rainfall. About half of the total land area, where precipitation is lower, is classified as desert or semi-desert.
In areas receiving at least 300 mm of annual rainfall, the natural vegetation consists of shrub or tree savannas dominated by Acacia species. This woody vegetation is disappearing at a rate of 480,000 hectares annually, of which less than 10 % is reforested. Following a number of government decrees passed in 1993, a total of 7.6 million hectares (equivalent to 3 % of the total land area) was declared as forest reserves. Of this, 453,000 ha (6 %) are plantation forests established using reforestation, and 42,000 ha (0.6 %) are community woodlots established through afforestation on denuded land.
The forestry sector in the Sudan produces 12 % of the gross domestic product. In addition, forests and trees provide significant benefits in the form of wood energy, fodder and grazing opportunities outside the market economy, and by protecting soil and water resources. The most important forest products are firewood and charcoal. As in many other countries, forest products in the Sudan are, to a great extent, derived from land that is normally not classified as forest. This has important implications for national and local-level forest management planning and forest policy development.
In the Sudan, gum arabic is an important non-wood product which is obtained from Acacia senegal. This tree occurs naturally on sandy soils, mainly in the 300 km wide 'gum belt' in central Sudan where annual precipitation is around 300-600 mm. The traditional agroforestry system, in which natural or artificially regenerated A. senegal trees are managed and tapped for gum during the fallow phase alternating with agricultural crops, is considered one of the best examples of sustainable dryland agroforestry. Apart from gum, A. senegal also yields fuelwood, local construction timber and dry-season fodder from leaves and pods.
With a total annual gum arabic production of 20-40,000 tons, the Sudan is the global leader in supplying this commodity, which is widely used as a stabiliser and natural additive in the food industry around the world. The current trend of consumer preferences for more natural and plant-based products (for instance, gum arabic instead of beef gelatine) in sweets and other foods is favouring increased use and production of gum arabic. This has created a new interest in traditional A. senegal agroforestry, which had been threatened by industrial, permanent agriculture and indiscriminate clearing of natural A. senegal forests.
In 1979, an afforestation and tree nursery project was initiated in the Sudan as part of the official Finnish development cooperation, with Enso Forest Development Ltd. as the main consultant. It included rehabilitation of the gum belt forests using A. senegal and the introduced Prosopis juliflora in forest plantations and village agroforestry systems, as well as development of forest nursery techniques. The associated research carried out by the University of Helsinki since 1983 was initially focused on tree seedling production and planting techniques, later it dealt increasingly with dryland ecology and natural forest management.
In 1991, when the Finnish-supported tree planting and nursery operations in the White Nile and Blue Nile regions were already showing encouraging results, most of the bilateral programme was abruptly discontinued because of sudden changes in development cooperation preferences. In the wake of the Gulf War, the same happened with almost all international development projects in the Sudan. However, the Finnish development agency (then known as FINNIDA), far-sightedly allowed the academic training of Sudanese researchers in Finland and the associated field research to continue. As a result, Finnish-trained doctoral degree holders now form the leadership of the principal government agency for forestry, the Forests National Corporation, as well as of the Forestry Research Centre, and the University of Khartoum Department of Forest Management.
Some of the scientific results of the Sudan-Finland cooperation (including Enso Forest Development Ltd., several University of Helsinki departments, and other partners in Finland) have already been published and can be summarised as follows: (1) Suitable semi-mechanised seedling production techniques are available for use in large-scale central tree nurseries; (2) the genetic population structure of Faidherbia albida, as indicated by isoenzyme and ecophysiological studies, suggests distinct ecotypic and geographic (between Sahelian and other origins) differentiation; (3) forest plantations studied in the Blue Nile floodplain areas offer economically and socially feasible land-use alternatives to agricultural crops; (4) natural Acacia seyal forests of the clay soils can be sustainably managed with appropriate silvicultural interventions and especially when integrated into traditional land-use; (5) in the rainfed sandy soil areas, Prosopis juliflora has favourable effects on agricultural crops, which can be further increased with management.
After having built up a strong institutional capacity for dryland forestry research in the Sudan, as well as in Kenya, the Tropical Silviculture Unit (TSU) at the University of Helsinki is now continuing field research in the Sudan with a focus on the development of traditional A. senegal agroforestry. The present three-year project is supported by the Academy of Finland. Its aims include: finding new artificial and natural regeneration techniques; increasing gum and woody biomass yields through tree genotype selection and management interventions; optimising tree-crop interactions; and identifying ecophysiological characteristics in A. senegal and agricultural crops, which can be used to predict the agroforestry system performance. This work is linked to separate studies on the socio-economic aspects of gum arabic production.
Contacts with other interested researchers and institutions are very welcome. More information can be obtained from the authors at:
Tropical Silviculture Unit
P.B. 28, FIN-00014 University of Helsinki,
Finland
Tel. +358-9-70858642, fax +358-9-70858646
E-mail: olavi.luukanen@helsinki.fi or
http://honeybee.helsinki.fi/tropic
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LOCAL FOREST MANAGEMENT IN THE SAHEL: PRELIMINARY RESEARCH RESULTS
by Paul Kerkhof
SOS Sahel (GB) has been carrying out research on 'Initiatives in local management of dryland forest areas in the Sudano-Sahelian zone' since 1996. Funded under research grant R6510 of the Forestry Research Programme, UK Department for International Development, the project was first announced in ETFRN Newsletter no. 20, 1997. The research is concentrated on the Sudan-Sahel zone (average annual rainfall 100-600mm/year, hereafter called 'Sahel'). This article presents preliminary conclusions.
In ecological terms, the Sahel is characterised by major abiotic events, droughts in particular, which tend to create a disequilibrium. It is not clear whether Sahelian ecology can best be explained by a non-Clementsian disequilibrium model or whether it is merely affected by major disturbances. In either case, conventional forestry planning tools based on stable, sustainable annual off-takes ('quotas'), can hardly be applied.
In economic terms, the research case studies show that forest products other than firewood, especially livestock, construction timber and fruit, are the most important revenue earners. Although poorer sections of the local society tend to benefit most from forest exploitation, the very poorest people hardly benefit because they often lack the physical capacity for the hard work required. An 'economic nomadism' prevails in which forest exploitation, migration, artisanal production and other secondary economic activities are undertaken as a function of the highly variable agricultural production. In any case, the relations between the different interest groups are complex, dynamic and locally defined, which further complicates the quota system.
These conclusions are important in the light of the prevailing policy for local forest management in the Sahel, the World Bank supported 'Domestic Energy Strategy' and the rural firewood markets. The SOS Sahel study shows that institutions, laws and fiscal policy in many Sahelian countries are currently being reformed in a way which allows a single stakeholder (the commercial firewood producer) to impose on a multi-stakeholder resource (the Sahelian forest).
In institutional terms, the research to date concludes that decentralisation is the driving force in local forest management. International conventions are in principle supportive, but their influence tends to be weak. Emerging environmental institutions could be supportive given their integrated objectives, but they do not have sufficient impact at a local level. The forest service has hardly been supportive to local forest management, as central planning and rent-seeking behaviour are still a driving force among their agents. Given the mission and ideology of the forest service, its role in the development of local forest management is likely to be limited in the near future.
Local institutions lack legal recognition and are often not fully representative of the various user groups. Internal and external regulations are rarely transparent, and accountability is often poor. For successful local forest management, institutional capacities need to be strengthened. This can, to a certain extent, be achieved by exploiting capacities which often exist at village level, for instance those used to manage the school, first aid centre and credit scheme. Secondly, forest management tools should be shaped to suit local capacity, and not the other way around. The quota system should be abandoned and locally manageable monitoring systems should be developed instead. SOS Sahel's action-research has contributed to finding alternatives to classic forest inventory through the use of panoramic photography and local forest product counting.
Furthermore, local institutions should be legally recognised with exclusive management rights, even if such rights are subjected to conditions of 'good management'. Finally, good governance at higher levels is a sine qua non for successful forest management at the lowest level.
For further information, please contact:
Paul Kerkhof
SOS Sahel (GB)
Tel/Fax +33 474720226
106446.2446@compuserve.com
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IMPROVED MANAGEMENT OF AGROFORESTRY PARKLAND SYSTEMS IN SUB-SAHARAN AFRICA
by Zewge Teklehaimanot
This research project (Contract No ERB IC18-CT98-0261) is funded by the Commission of European Communities, Directorate General XII, under the programme of Co-operation with Developing Countries (INCO-DC). Its planned duration is four years, from October 1998 to September 2002. A large number of partners are involved:
1. Co-ordinator, University of Wales Bangor (UWB), U.K.
2. Ben Gurion University (BGU), Israel.
3. Centre National de Semences Forestière (CNSF), Burkina Faso.
4. Co-operative Office for Voluntary Organisations of Uganda (COVOL), Uganda
5. University of Freiburg (UF), Germany.
6. Centre International de Recherche en Agronomie pour le Développement (CIRAD.Forêt), France.
7. Wageningen Agricultural University (WAU), the Netherlands
8. Institut de l'Environnement et de Recherches Agricoles (INERA), Burkina Faso
9. PROPAGE, France.
10. Istituto Sperimentale per la Elaiotecnica (ISE), Italy.
11. AARHUS Oliefabrik, Denmark.
12. Université Pierre et Marie Curie (UPMC), France.
13. Institut d'Economie Rurale (IER), Mali.
14. University of Ibadan (UI), Nigeria.
15. International Centre for Research in Agroforestry (ICRAF/SALWA), Mali
General Objectives of the Project
1. To promote security and self-sufficiency in food production in Sub-Saharan Africa (SSA) a) by enhancing the productivity of traditional agroforestry parkland systems, and b) by maximising the economic values and optimising the marketing of parkland tree products (with particular emphasis on Parkia biglobosa and Vitellaria paradoxa).
2. To help reverse the trend of environmental degradation and combat desertification in SSA by a) conserving the biodiversity of parklands, and b) promoting the sustainable use of indigenous woody plant resources.
3. To use and develop the expertise of North and South research teams through the use of advanced technologies and enhance North/South collaboration to achieve a sustainable improvement in agricultural production and natural resource management in SSA.
Approach & methodology
Traditional agroforestry parkland systems - where annual crops are grown in fields with scattered, 'protected' trees - are one of the most widespread system of land use in SSA. Recent evidence, however, suggests that parklands have been degrading, at the system, species and genetic level. This research project, therefore, proposes to initiate an integrated and multi-disciplinary approach in order to reverse this trend. Initially, the indigenous knowledge and management practices of parkland systems will be studied so that due prominence is given to local people's knowledge and practices in the research and future improvement of parklands. Possibilities for improving parklands' productivity through the use of different pruning regimes for Vitellaria paradoxa and Parkia biglobosa will be investigated. The impacts of different parkland management practices on plant resource diversity will be assessed at systems, species and genetic levels. Methods of improving Vitellaria and Parkia trees will be investigated through selection of superior genotypes and by developing methods to enhance their growth and fruit yield. The chemical composition of Vitellaria and Parkia fruit will also be investigated to identify compounds with commercial potential. Constraints in the current marketing and processing practices of Vitellaria and Parkia products will be identified.
Expected results and importance for Sub-Saharan Africa
The project aims to develop methods to enhance the agricultural and economic productivity of parklands in SSA, at the same time as conserving and restoring biodiversity. This will be achieved by obtaining higher yields of annual crops through better tree-crop combinations and improved tree management, generation of greater value from tree products through development and reintroduction of improved cultivars of Vitellaria and Parkia, improving storage and processing methods, and by identification of unique fruit compounds with commercial potential. A unique database of marketing information will also be developed to improve existing methods, develop new marketing channels and recommend appropriate price structures such that farmers, traders, processors and consumers are all reasonably satisfied, without either the traders or the processors making an excessive profit at the expense of the farmers.
The major goal of the proposed project is the improvement of traditional agroforestry parklands, which has fundamental bearings on food security and sustainable natural resource management in SSA. Intended benefits include the restoration of tree resources to parklands, and an increased supply of products from Vitellaria and Parkia. The domestication of Vitellaria and Parkia in parklands through improved agroforestry practices will enable farmers' families to make nutritional gains and to generate cash income from the sale of the fruit. The existence of regional and international markets for Vitellaria and Parkia products offers remarkable opportunities for the development of agriculturally-based industries in SSA.
For further information please contact the Project contact and Coordinator:
Dr Zewge Teklehaimanot
School of Agricultural and Forest Sciences
University of Wales Bangor
Gwynedd LL57 2UW, UK
Tel: +44 1248 382639
Fax: +44 1248 354997
E-mail: z.teklehaimanot@bangor ac.uk
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MODERNISATION D'UN PROGRAMME DE RECHERCHE SUR LA FORET ET L'ARBRE AU MALI
(Modernisation of a research programme on forests and trees in Mali)
by Amadou Malé Kouyaté and Jean-Pierre Sorg
Sikasso, la capitale de la 3e Région du Mali, héberge une intéressante unité de recherche sur la gestion des ressources forestières, appuyée par le régisseur Intercooperation (Berne, Suisse) sur financement de la coopération suisse.
Les activités de recherche avaient été conçues au départ, vers 1986, de façon modeste dans le cadre des besoins du service forestier local. Leur finalité était dans une grande mesure technique et concernait la pépinière, le reboisement et l'amélioration des forêts naturelles. Les relations avec des acteurs non forestiers étaient alors plutôt timides. Aujourd'hui, cette unité gère un programme régional dynamique, d'un bon niveau scientifique, et poursuit sa transformation en une structure résolument participative au sein de l'Institut d'Economie Rurale, l'institution de recherche agronomique au Mali.
La recherche participative se déroule en contact étroit avec le milieu rural. Les paysannes et les paysans définissent leurs besoins et participent à la préparation, au suivi et à l'évaluation d'activités de recherche dont ils sont les premiers bénéficiaires. A Sikasso, la recherche forestière n'hésite pas à se présenter à ses partenaires - paysans, vulgarisateurs, services agricoles et forestiers - et à se soumettre à leur critique.
Les aspects techniques sont toujours présents, mais les recherches s'insèrent désormais dans une démarche de gestion des ressources de l'arbre et de la forêt. Le bois est une production parmi d'autres qui sont parfois plus importantes, à l'exemple du fourrage, des fruits et des plantes médicinales. L'arbre et la forêt font partie du terroir villageois, l'espace régi par la coutume et dans lequel une population exerce ses activités culturelles, sociales et économiques.
La recherche forestière est devenu pluridisciplinaire; les forestiers travaillent avec des agronomes, des sociologues et, bien sûr, avec les femmes et les hommes du terroir, dans le but d'assurer une gestion raisonnable de l'ensemble des ressources naturelles.
For further information, please contact:
Amadou Malé Kouyaté
CRRA/ARFP
BP 164
Sikasso
Mali
Email: akouyaté@malinet.ml
Jean-Pierre Sorg
ETH-Zentrum
Waldbau
CH-8092 Zurich
Switzerland
E-mail: sorg@waho.ethz.ch
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THE CONTRIBUTION OF FOREST PRODUCT COMMERCIALISATION TO RURAL LIVELIHOODS IN SOUTHERN ZIMBABWE
by Oliver Braedt, Jobst-Michael Schröder and Jochen Heuveldop
Background
Since July 1996 the Institute for World Forestry at the Federal Research Centre for Forestry and Forest Products, Hamburg, Germany, in collaboration with the Institute of Environmental Studies at the University of Zimbabwe, Harare, and the Center for International Forestry Research (CIFOR), Bogor, Indonesia, have been carrying out research on the socio-economic contribution of forest products to rural households in Zimbabwe.
In recent years markets selling woodcrafts and other forest products as curios have been expanding in number and size along main roads in Zimbabwe. The rapid growth of the craft industry has raised concerns in governmental institutions and environmental groups about degradation of forested lands caused by uncontrolled timber consumption. However, lack of information about the craft industry has prevented authorities from taking decisions on whether to promote or hinder this sector.
Essential data needed include the actual extent in number and size of the craft industry at national level and the types of products offered. There are no figures on the types of people participating in the sale of forest products and the economic importance of the handicraft industry at household, village and ward level. Institutional arrangements governing the commercialisation of forest products sold as curios need to be identified and existing rules and regulations noted.
ObjectiveThe main objective of the study is to analyse and document the importance of forest product commercialisation for rural livelihoods in Zimbabwe. Results are intended to contribute information towards the formulation of frameworks for necessary policy decisions, such as those regulating the environmental impact caused by the increased commercialisation of forest products as curios.
Method
In order to obtain information on the actual extent and size of the craft industry in Zimbabwe, 16 tourist routes - defined as main roads between major towns and important tourist attractions - were surveyed on a yearly basis. Only markets on rural roadsides, outside urban centres, were studied. Markets offering all types of material were included.
Three wards in Chivi District, southern Zimbabwe, were chosen for detailed studies on markets and households. All markets in the area were visited regularly and information was obtained through interviews with individuals and groups, as well as by recording tree species used and measuring their timber volumes. Gender, social dynamics and institutional issues were addressed. Randomly selected households were visited on a yearly and some on a monthly basis. Data describing the general socio-economic setting, the income structure of the area and the extent of participation in the craft industry were collected during interviews with household heads.
Participatory rural appraisal (PRA) tools were used in group discussions on markets. Formal questionnaires were administered with individual households, market participants and officials, and semi-structured and open-ended interviews took place with groups and individuals. Emphasis was laid on participatory and direct observation at craft markets and households. The data underlying this research were collected during 1997 and 1998.
Preliminary Results
In 1998 more than 200 craft markets of different size were located along roadsides leading to tourist attractions and major towns in Zimbabwe. More than 80 % of these markets only emerged after 1990. In total, seven significant types of raw material (wood, stone, clay, grasses and palm leaves, bark of Andansonia digitata, cotton thread and wool) were distinguished. Wooden objects dominated the material range, and were found on 68 % of all markets surveyed. Wood carvings are mainly produced by individual self-trained artisans or rarely by small village groups. The preferred timber species for the curios are almost exclusively five indigenous tree species (Afzelia quanzensis, Baikiaea plurijuga, Combretum imberbe, Kirkia acuminata and Pterocarpus angolensis), yet all five species are protected from unauthorised cutting by forest law in Zimbabwe. Of the craft markets recorded throughout the country, 11 % were located in the surveyed district with eight markets being located in the three study wards.
Different steps within the production chain were identified and the contribution of each step towards rural household incomes was noted. Some 20 % of the households in the study area were found to obtain earnings through the commercialisation of craft products. Although money gained through the craft industry was less than 6 % of the gross annual cash income, for some households the sale of curios at roadside markets was the only source of cash.
Current institutional arrangements concerning the harvesting of trees for the craft trade in communal areas were analysed. Results indicate that existing legal and traditional institutions are largely disregarded by user-specific or interest-based groups and individuals whose concern is not oriented towards the benefit of the whole community. Existing legislature and taboos regulating the use of trees are currently not adhered to and the knowledge of codified regulations at village and ward level is deteriorating markedly in the communal lands of southern Zimbabwe.
Final results of the study are expected by the end of the year 2000.
Acknowledgements
The funds for this research project were provided by the Center for International Forestry Research (CIFOR), Bogor, Indonesia, financed by the German Federal Ministry for Economic Co-operation and Development (BMZ).
For further information, please contact the
authors at:
Institute for World Forestry
Federal Research Centre for Forestry and
Forest Products
Leuschnerstraße 91
D-21027 Hamburg
Germany
Tel:+49 (0)40 73962 100
Fax: +49-40-73962 480
E-mail: braedt@aixh0101.holz.uni-hamburg.de
http://www.dainet.de/bfh
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SOCIAL BENEFITS AND TREE SPECIES DIVERSITY IN NATURAL AND PLANTATION FORESTS IN NORTHEAST ZIMBABWE
by Tapani Tyynelä
The majority of people in southern Africa live on customary or communal land and are dependent on the resources these lands can provide. In Zimbabwe, the main land tenure categories include communal areas (42.0 %), large-scale commercial farms (32.5 %) and resettlement areas (6.8 %).
Communal areas support about 70 % of the total population, which has often been devastating for the environment. Most of the woodlands in communal areas have been deforested due to the high population pressure. In spite of the pressure on wood resources, however, local people have not experienced severe wood shortages. The main reason for this has been a significant increase in tree planting in the last 15 years, which has substituted for the natural resource.
Exotic species, and especially Eucalyptus spp., have dominated tree planting in Zimbabwe. At the same time as tree planting has increased, the availability of traditional woodland products has decreased, especially fruit, poles and firewood. Key research questions are whether customary and communal management systems have promoted rather than prevented the deterioration of natural forests, and whether changes from traditional forest management towards more plantation-oriented forestry practices have decreased the biodiversity value of forests in Zimbabwe.
This article is a short introduction to a PhD-study focusing on the above-mentioned research problems. The specific aim of the study was to assess the impacts of various land management categories on the socio-economic benefits obtained from the forests, and compare the tree species diversity in managed natural forests and Eucalyptus camaldulensis plantations. The land management categories studied were communal, resettlement and large-scale commercial farm areas.
Tree species diversity (including the Berger and Parker (D´) and the Shannon and Wiener (H´) indices) was measured in a systematic sample of forest sites around villages and resettlement areas. Tree species were recorded at 200 and 800 metres from the village centre. Preliminary results support the expectations that Eucalyptus plantations are poorer in species diversity than the natural forests nearby. However, there are also examples of plantations with lots of tree species and natural forests with few tree species. It seems that the owner class (private, school owned or co-operative plantations) and the quality of management have effects on tree species diversity in Eucalyptus plantations. Generally, plantations have higher basal areas and volumes per hectare than the natural forests nearby.
The socio-economic benefits obtained from the forests were investigated using Participatory Rural Appraisal (PRA) techniques, especially mapping, ranking and scoring. Semi-structured interviews were carried out with plantation owners and traditional leaders. The preliminary results show that, in spite of rapid deforestation in the last three decades, the benefits of natural forests are still very important especially for the poor in communal areas. The rich are not so dependant on natural vvforests and can benefit more from Eucalyptus plantations. However, the situation is now changing so that poorer people will also have plantations in the future.
For further information please contact:
Mr Tapani Tyynelä,
Faculty of Forestry, University of Joensuu,
P.O. Box 111, 80101 Joensuu
Finland
Tel: +358 13 2514397
Fax: +358 13 2513590
E-mail: tapani.tyynela@forest.joensuu.fi
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PROSOPIS - PEST OR PROVIDENCE, WEED OR WONDER TREE?
by Nick Pasiecznik
"So mesquite is something more than a tree, it is almost an elemental force, comparable to fire - too valuable to extinguish completely and too dangerous to trust unwatched" (Peattie, 1953).
Some of the most widespread tree species in the world's deserts, Prosopis (mesquite) are proclaimed both as a saviour and disaster. Foresters, environmentalists and researchers all voice their opinions, rarely coinciding, and send a confused message to extension workers and farmers. Like Eucalyptus, which raise concerns about water use, Prosopis are seen as a weed and worse. Several species have been introduced from the Americas and are now common world-wide, mainly the sub-tropical P. glandulosa and P. velutina and the truly tropical P. juliflora and P. pallida. These are fast growing, nitrogen-fixing, very salt and drought tolerant trees that coppice well. The wood is hard and durable and an excellent fuel and timber. Flowers provide bee forage, and sweet, nutritious pods are relished by livestock and made into human food. Foliage is rarely browsed but leaf litter improves soil quality. However, large, stout thorns are positively disliked, and after cutting or browsing, trees produce many basal stems leading to a shrubby, multi-stemmed form. Seeds pass through animals' stomachs undigested, the process aiding germination, and are spread widely by livestock and water. Tap roots can reach deep water tables and extensive lateral roots spread well beyond the crown.
Invading Prosopis tends to form dense, impenetrable thickets. In pastures, it reduces grass cover and stocking density, threatening ranchers' livelihoods, even forcing the migration of traditional pastoralists. Invasions into agricultural land, along irrigation channels and water courses, is also a major problem. The trees are believed to deplete groundwater reserves and to reduce the growth of neighbouring crops. Prosopis pollen is said to be a major cause of allergic reactions, the thorns to be poisonous, and the trees to harbour nematodes. Although the trees have many competitive ecological advantages over other plants, the seedlings are sensitive. They often colonise disturbed, eroded, over-grazed or drought-ridden land associated with unsustainable agronomic practices, such as following the introduction of cattle ranching in the Americas. Millions of hectares of rangeland have been invaded in this century, and the process is still occurring in South Africa, Australia and coastal Asia, where Prosopis species have been introduced. However, the ability to establish easily is an advantage for firewood collectors, who can find Prosopis on even the poorest of sites.
Prosopis are phreatophytes with deep tap roots to keep trees green during droughts by accessing the water table, and lateral roots to draw on surface water during the rains. Leaf adaptations reduce water loss, as expected in desert plants. Pot studies do not reflect actual water use in the field, and re-appearance of streams after land clearance has been explained by increased soil permeability following stump removal. Prosopis are not voracious water users. Research on allelopathic effects shows decreased seed germination and seedling growth, with negative effects apparently due to shade and root competition. However, there are many conflicting reports of plants being lusher and growing quicker under Prosopis canopies. Increased nematode populations near Prosopis are unconfirmed. Deaths from thorn pricks have been explained by secondary infection, although stout thorns certainly penetrate most shoes and are likely to cause injury. Where Prosopis are the most common trees, the pollen has been recorded as a major allergen.
Views for and against Prosopis come from different quarters. "The popularity of P. juliflora is income related, those that can afford bottled gas for cooking and do not have to raise livestock quickly forget its value as a fuel and fodder tree. Comments concerning its monoculture, lack of aesthetic value and unconfirmed beliefs on the lowering of water tables come only from the more affluent. Rural farmers are invariably aware of its importance" (Pasiecznik, 1998). Prosopis is generally the scourge of ranchers and pastoralists, but a boon to the rural poor. In contrast to negative views of Prosopis as a weed, in India, where Prosopis provides up to 70 % of the firewood needs of rural populations in dry regions, only its value is noted. "The rebellious sands are subdued and the inhospitable soils are colonised. The dreary scene of dry districts is changed to that of green belts. The bleak tree-less landscape is painted with splashes of brown, green and yellow. The monotony is broken for the traveller and the sheep and goats munch and crunch happily on the proteinous pods. The rural folk, whose lands were getting buried under drifting sands are grateful to the Forester and Prosopis, and the poor folk who had no fuel to burn in their hearths now have Prosopis. They collect the fuel in their leisure and sell in towns for a decent price" (Konda Reddy, 1978).
For over fifty years, ranchers in south-western USA and Argentina tried every possible technique to eradicate or control Prosopis. The end result? Millions of dollars spent and still no cost effective programme found. In Sudan, the eradication programme even trains children to uproot seedlings. In South Africa and Australia amongst others, eradication or control programmes exist, and new methods of biological control using seed-eating beetles are being attempted. However, it seems that once it has arrived, Prosopis is there to stay, so why not learn how to live in harmony with this new neighbour? Some change in land-use systems appears necessary. Cattle spread seed widely, for example, whereas sheep kill most seed ingested and pigs kill them all. A reduction in stocking rates can encourage good grass cover, which prevents seedling establishment. But what to do with dense stands? They must be thinned, which is not a desirable job, to 100-200 stems per hectare. Stumps have to be removed or treated. Remaining trees must be pruned to single stems. Seedlings do not establish under tree canopies, so such a cover will prevent further establishment. Pruned crowns reduce root competition and grass growth will improve. With the production of fuelwood, sweet pods and straight trunks for timber, this can only be a profitable use of otherwise unproductive lands.
References
Konda Reddy, C.V. 1978. Prosopis juliflora, the precocious child of the plant world. Indian Forester 104: 14-17.
Pasiecznik, N.M. 1998. Prosopis and provenance research in Cape Verde. pp 73-76 in: J.C. Tewari, N.M. Pasiecznik, L.N. Harsh and P.J.C. Harris (eds.), Prosopis Species in the Arid and Semi-Arid Zones of India. The Prosopis Society of India and the Henry Doubleday Research Association, Coventry, U.K.
Peattie, D.C. 1953. Natural History of Western Trees. Riverside Press, Cambridge, Boston, USA.
HDRA are also seeking research cooperation - please see page .........
For further information, please contact:
N M Pasiecznik
The Henry Doubleday Research Association
Ryton-on-Dunsmore
Coventry CV8 3LG, United Kingdom
Tel: +44 1203 308200; Fax: +44 1203 639229
E-mail: npasiecznik@hdra.org.uk
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MEDCHANGE - CHANGING LAND USE PRACTICES IN FOREST AND GRAZING ECOSYSTEMS - MEDCHANGE
by C Coelho (1); M Sala (2); M Tanago (3); A Laouina (4); A Hamza (5)
Introduction
The overall objective of the project 'Effects of land use and land management practices changes on land degradation under forest and grazing ecosystems' (MEDCHANGE) is to investigate the impacts of land-use and land management practice changes in areas of the Western Mediterranean that are vulnerable to land degradation and desertification.
The project seeks:
1. to investigate how increased forest and grazing activities affect land degradation in the Western Mediterranean region (Morocco, Tunisia and the Iberian Peninsula);
2. to assess the current and probable future land-use and land-management practice changes which may be induced in areas vulnerable to land degradation and desertification by contemporary socio-economic trends, national/regional policies, the 2010 free trade zone and the EU CAP Aid Scheme for Forestry.
To achieve these objectives, the project has taken a holistic approach, combining both environmental and socio-economic dimensions. By so doing, it hopes to improve the basis of policies in support of sustainable development; to evaluate the effects of natural conditions and human activities on water depletion, soil degradation and vegetation health; to establish optimal practices for land management, in order to achieve greater sustainability through a reconciliation of potentially conflicting interests; to contribute to the definition of criteria for evaluation and mitigation of land degradation; and to disseminate results among rural populations and government officials.
Study areas
The Medchange project works in nine study areas (see Figure 1) which were selected on the basis of their serious land degradation and desertification problems, brought about by changes in socio-economic, demographic and natural conditions. The choice of sites allows for a comparison of the two margins of the Mediterranean, both in relation to socio-economic profiles and to land uses and land management techniques practised at each site.
A core of six areas is associated with the climax distribution of Quercus suber and Quercus ilex (Portugal - Mação and Portel; Spain - Gavares; Morocco - Ksar el Kebir and Ben Slimane; and Tunisia - Azmour), and provides a more or less uniform base for a comparison of different land management practices and socio-economic factors. Two sites are cooler and wetter (Canencia, a Quercus pyrenaica forest in the Guadarrama Mountains; and the Port del Compte, an area dominated by Pinus nigra and Pinus laricio in the pre-Pyrenees in Spain), while the final site has a drier climate (Ain Khmaissia in Tunisia, which is a typically arid environment dominated by Quercus ilex and Alep Pine).
Marginal areas of the Iberian Peninsula are suffering heavy population losses towards the more developed areas. This has led to the abandoning of agriculture, an increase in the lands under forest and greater growth of understorey vegetation. This, in turn, is accompanied by a growing risk of forest fires, the spatial expansion of land degradation, and increasingly unregulated traditional agro-forestry systems.
In contrast, the Moroccan and Tunisian study areas are still experiencing increasing rural populations, and the high human densities (173 people/km2 in Azmour and 120 people/km2 in Aim Khmaissia) are causing serious land degradation, with socio-economic deterioration and poverty as a consequence. The growing population making a living from an agro-silvo-pastoral system, has put pressure on natural resources, leading to the intensification of agriculture and grazing and the use of non-traditional land management practices. The original vegetation has progressively been replaced by agriculture, mainly wheat and barley, with irrigated crops in the flat plains.
Methodology
Activities can be divided into four major groups:
1) Evaluation of current responses and prediction of likely future responses in terms of land-use and land management practices to (i) national/regional government policies (soil-water conservation) and (ii) contemporary socio-economic trends. This includes: (a) establishing exactly what the policies are; (b) an assessment of current land-use and recent land-use trends in the study regions, using national/regional demographic and agricultural statistics; (c) structured interviews with forestry, agricultural and local government administrators and officials concerning current/future land-use and land management problems as well as impacts of international, national/regional policies, (with special emphasis on the impacts of the 2010 free trade zone and EU CAP Aid Scheme for Forestry); and (d) a questionnaire survey of land users on their views of current/future land-use and land-management practice trends and problems, as well as their responses to national initiatives and policy.
2) Gathering of data on hydrology, erosion, soils and vegetation for the different land-use/land-management practice types within each of the study areas. This includes: (a) the identification and specification of the land-use/land-management practice types within the study areas; (b) sampling of the key surface and soil properties that influence erosion and hydrology; (c) rainfall simulation experiments to establish susceptibility to erosion and overland flow dynamics; (d) analysis of existing rainfall and river flow records to establish basin-scale hydrological characteristics of the principal land-use types; and (e) measurement and modelling of hydrology and sediment yield.
3) Use of data gathered in the previous steps to predict erosion, hydrological and soil sustainability consequences of the land-use/land-management practice changes. Particular attention will be paid to those land uses expected to arise from the national/ regional soil-water conservation strategies and land-management practice alternatives.
4) Proposing recommendations on possible modifications to national/regional policies to minimise any adverse environmental consequences.
(1) Departamento de Ambiente e Ordenamento, Universidade de Aveiro, Portugal;
(2) Grupo de Reserca Ambiental Mediterranea, Universidad de Barcelona, Spain;
(3) Laboratorio de Hidraulica e Hidrologia, Universidad Politécnica de Madrid, Spain;
(4) Laboratoire de Geomorphologie, Université Mohamen V, Morocco;
(5) Institut National de Agronomique de Tunisie, Tunisia
For further information, please contact:
Celeste Coelho
Dep. Ambiente e Ordenamento
Universidade de Aveiro
3810 Aveiro, Portugal
Email: Coelho@dao.ua.pt
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CONSERVATION THROUGH USE OF TREE SPECIES DIVERSITY IN FRAGMENTED MESOAMERICAN DRY FOREST (CUBOS)
Implemented jointly by the Oxford Forestry Institute and the Overseas Development Institute, this project aims to evaluate the potential for conservation of tree species diversity through use within farm-forest landscapes in two fragmented dry tropical forest zones in Honduras and Mexico. It began in September 1997 and will continue until August 2000.
Mesoamerican dry forest is of key global importance as a source of germplasm of a wide range of internationally-important multipurpose and industrial tree genera, including Albizia, Bombacopsis, Cordia, Gliricidia and Leucaena. At the same time, it is considered by some to be one of the most endangered tropical ecosystems worldwide, due to a combination of factors including ranching, smallholder agriculture and human-induced fire. Recognition of this fact and concern over the degradation of native populations of valuable tree genera has prompted the UK's Department for International Development (DFID - formerly ODA) to sponsor population explorations, seed collection and dissemination, ex situ conservation, tree improvement and breeding systems research in the region over the last two decades. The CUBOS project, funded by DFID's Forestry Research Programme, was initiated in recognition of the need to take human considerations into account in the designing of workable conservation strategies, and to allocate limited conservation resources efficiently on the basis of an informed and objective assessment of conservation priorities.
The research carried out by CUBOS is of three types:
Indications to date show that:
These findings have a number of important implications for the conservation of tree species diversity:
Although field research has been concentrated on Honduras and Mexico, it is hoped that the results of CUBOS will be of relevance to dry forest throughout the whole of Mesoamerica and possibly beyond. Results will be presented and discussed at a regional workshop at the end of the project. In the interim, interaction with conservation, rural development and research bodies elsewhere in Mesoamerica would be welcomed.
For further information, please contact:
Jamie Gordon
Department of Plant Sciences
University of Oxford
South Parks Road
Oxford, UK
E-mail: jamie.gordon@plants.ox.ac.uk
Adrian Barrance
Apartado Postal 5928
Tegucigalpa
Honduras
Tel: +504-766 2803
E-mail: odi@gbm.hn
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