Agroforestry parklands in sub-Saharan Africa
Table of Contents

J.-M. Boffa

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ISBN 92-5-104376-0

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The ecological and socio-economic importance of traditional agroforestry systems is now widely recognized. These land-use systems provide various useful products for household and national economies including food and medicinal products for humans and animals, wood for construction and fuel, and cash income. They contribute to the sustainability of soil nutrient and water cycles and buffer climatic extremes. This is particularly true of agroforestry parklands, the most widespread agroforestry systems in the semi-arid zones of West Africa. Their social and ecological values also carry a high significance. This and the fact that they have been subject to severe droughts and utilization pressure in the last decades have led to a growing interest in promoting their conservation and in further improving their management to increase the benefits they provide to farmers.

A basic challenge in the field of agroforestry is how to make a tangible difference for farmers. The capacity of researchers, practitioners, conservationists and policy-makers to learn how to assist farmers to manage agroforestry parkland systems in more productive and sustainable ways relies primarily on the availability of cogent, comprehensive, up-to-date information, which reflects the complex nature of farmers' decisions. The initiative taken by FAO to contribute to a better knowledge of concepts and the synthesis of experiences relating to Soudano-Sahelian parklands reflects the awareness of the Organization of the roles and functions of these systems.

Several meetings and publications have helped research and development efforts in this field. A particularly significant event was the 1993 conference on Agroforestry Parklands of the West African Semi-Arid Lands organized by ICRAF in Ouagadougou, which brought together people from various disciplines and geographic areas. Other major initiatives include the recent ICRAF/SALWA country reports on parklands in Senegal, Mali, Burkina Faso and Niger, the 1991 ICRISAT-ICRAF workshop on Faidherbia albida in the West African semi-arid tropics in Niamey, CIRAD-Forêt's works on F. albida including the 1998 monograph on the species, and the 1998 Working Meeting on shea nut tree (Vitellaria paradoxa, karité) at FAO. The recent Vitellaria paradoxa and Parkia biglobosa monographs from the University of Wales at Bangor add to this interesting collection. In order to give a renewed impetus to the work on these systems, FAO felt that the time was ripe to attempt the production of a state of knowledge paper integrating a wide range of information on the biophysical, socio-economic and policy aspects relating to the understanding and sustainable management of parkland species and systems. Jean-Marc Boffa, who has done extensive systems-oriented research, both biophysical and socio-economic on Vitellaria parklands in West Africa was an excellent candidate to be assigned the task.

The project originated with and has been coordinated by El-Hadji Sène, Chief of Forest Conservation, Research and Education Service in the Forest Resources Division of FAO's Forest Department. Susan Braatz, then forestry officer in charge of agroforestry in the Forest Resource Division started off the process. Michelle Gauthier, replacing Susan Braatz, took up the final steps of the project. Lise Andreasen and Michel Malagnoux have provided valuable comments and been involved in its follow-up. FAO also commissioned six parkland experts, Edouard Bonkoungou, Denis Depommier, Mark Freudenberger, Amadou Maïga, Madické Niang, and Kathrin Schreckenberg, to carry out a thorough review of the document. Technical and copy-editing was undertaken by Kathrin Schreckenberg from the Overseas Development Institute in London.

This study is part of the Conservation Guides series. It is targeted at all those with an interest in rural development, particularly agroforestry practitioners and researchers, but also policy- and decision-makers in the fields of agriculture, forestry and conservation in West Africa and beyond. I hope that it will encourage more integration in approaches, a higher degree of multidisciplinarity and more practical solutions to rural needs. It will be particularly useful for people working in the Sahel and Sudan zones of West Africa, but should also be of interest to a wide range of professionals working on agroforestry systems in other regions of the world outlining, as it does, many concepts underlying the value of trees within farming landscapes. This review is also relevant to FAO's interest and involvement in the assessment of forest resources outside forests, which are of increasing importance as pressure on resources in natural forest and tree stands rises. More research cooperation in development and dialogue on parklands are still needed and FAO welcomes observations and comments from readers for inclusion in future related studies.

Jean Clément
Forest Resources Division


This document attempts to present the current state of knowledge on agroforestry parkland systems. These systems, which for many local populations are very important for food security, income generation and environmental protection, are found primarily in the semi-arid and sub-humid zones of West Africa. The document first provides a thorough description of their distribution and diversity and discusses different ways of classifying them. It also presents data on current trends in parkland development and assesses determining factors. The document then provides an in-depth analysis of biophysical tree-soil-crop interactions and the factors regulating them, and describes various improved parkland management techniques. It goes on to examine the strength and limitations of institutional arrangements as well as the constraints imposed by Sahelian forest policies on the sustainable management of parklands. The production, use and marketing of parkland products is reviewed with an emphasis on their contribution to food security, local and national income as well as social values. Overall costs and benefits of the practice of parkland agroforestry are evaluated. In conclusion, the document identifies crucial research needs and promising avenues for promoting sustainable management of parkland systems.


Permission to use Vitellaria paradoxa, Parkia biglobosa and Balanites aegyptiaca distribution maps was kindly provided by Bangor University and specific thanks go to Jeremy Williams for supplying the first two in the correct format. Thanks are also expressed to CIRAD-Forêt for permission to reproduce the map of Faidherbia albida in Western Senegal. Photographs were provided by Christelle Bernard, Jean-Marc Boffa, Pascal Danthu, Roberto Faidutti, Dominique Louppe, Peter Lovett, Eliot Masters, Sibidi Jean Ouédraogo, Régis Peltier and Kathrin Schreckenberg.

List of Acronyms

AFRENAAgroforestry Research Network for Africa
APROMAAssociation des produits à marché (Bruxelles, Belgique)
ARDAssociates in Rural Development (Vermont, USA)
CADEFComité d'action pour le développement de Fogny (Sénégal)
CBECocoa butter equivalent
CBRsCocoa butter replacers
CDRComité pour la défense de la révolution (Burkina Faso)
CECCation exchange capacity
CFDTCompagnie française de développement des textiles (France)
CIEPACCentre international d'éducation permanente et d'aménagement concerté (Senegal)
CIFORCentre for International Forestry Research (Indonesia)
CILSSPermanent Interstate Committee for Drought Control in the Sahel / Comité interétats de lutte contre la sécheresse au Sahel
CINTECCompagnie internationale de négoce en transport et commerce (Burkina Faso)
CIRAD-SARCentre de coopération internationale en recherche agronomique pour le développement, Département systèmes agroalimentaires et ruraux (France)
CITECCompagnie industrielle du textile et du coton (Burkina Faso)
CNSFCentre national de semences forestières (Burkina Faso)
COVOLCooperative Office for Voluntary Organizations of Uganda (Uganda)
CTFTCentre technique forestier tropical (today CIRAD-Forêt) (France)
dbhDiameter at breast height
DFSCDANIDA Forest Seed Center (Humlebaek, Denmark)
ENEAÉcole nationale d'économie appliquée (Senegal)
FCFACFA franc (Communauté financière africaine) — currency used in French-speaking West Africa
GERES-CTFTGroupe d'études sur la restauration des sols, Centre technique forestier tropical (France)
GISGeographic Information System
GRAAPGroupe de recherche et d'appui pour l'auto-promotion paysanne
IAAIndol-3-acetic acid
IBAIndol-3-butyric acid
ICRAFInternational Centre for Research in Agroforestry (Kenya)
ICRISATInternational Crops Research Institute for the Semi-Arid Tropics (Niger)
ILCAInternational Livestock Centre for Africa (Ethiopia) (today, International Livestock Research Institute, Nairobi, Kenya)
IDRCInternational Development Research Center (Canada)
IPGRIInternational Plant Genetic Resources Institute (Italy)
IRHOOils and Oilseeds Research Institute / Institut de recherche pour les huiles et oléagineux
ISRAInstitut sénégalais de recherche agricole (Sénégal) / Agricultural Research Institute of Senegal
IUFROInternational Union of Forestry Research Organizations (Austria)
KESKenyan Shilling
LTCLand Tenure Center, University of Wisconsin-Madison (USA)
NAANapthalene acetic acid
NARSNational agricultural research systems
NGONon governmental organization
NTFPsNon-timber forest products
ODEPAOficina de Planificación Agrícola (Chile)
ORSTOMOffice de la recherche scientifique et technique outre-mer (today, Institut de Recherche pour le Développement, IRD) (France)
PARPhotosynthetically active radiation
PRSPRProgramme de recherche sur les systèmes de production ruraux (Mali)
R&DResearch and development
RDBFRépublique du Burkina Faso
RDMRépublique du Mali
RDNRépublique du Niger
RDSRépublique du Sénégal
SALWASemi-Arid Lowlands of West Africa
SOCADASociété centrafricaine de développement agricole Central African Agricultural Development Agency
SODECOTONSociété de développement du coton (Cameroon)
UNIFEMUnited Nations Development Fund for Women
USAIDUnited States Agency for International Development

Food and Agriculture Organization of the United Nations
Rome, 1999 © FAO

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This electronic document has been scanned using optical character recognition (OCR) software. FAO declines all responsibility for any discrepancies that may exist between the present document and its original printed version.

Table of Contents






Parklands: A review of definitions and terminology

Parklands in West Africa
Areal extent
Characterization by dominant species

Faidherbia albida
Vitellaria paradoxa
Parkia biglobosa
Other important parkland species

Factors used in establishing parkland typologies
Degree of human intervention
Functional classification
Spatial analysis

Parklands as a reflection of agrosystems and ethnicity



Changes in tree density over time

Natural factors

Economic and socio-cultural driving forces

Agricultural development policies
Role of trees in agricultural development models
Crop introduction and development
Fertilizer policies

Demographic relations



Tree-soil relations

Influence on soil chemistry

Savanna tree species
Parkland tree species

Influence of trees on mineral content of understorey plants
Mechanisms of soil fertility improvement

Soil microbial activity and structure
Atmospheric inputs
Nitrogen fixation
Dung deposition
Pre-existing soil fertility
Soil management practices

Nutrient enrichment with increasing tree size
Parkland density and soil fertility
Nutrient redistribution versus enrichment
Underground tree-crop interactions

Relations between woody and herbaceous plants
Influence of trees on biomass productivity
Influence of trees on grain yields of crops

Faidherbia albida, a tree with reverse leaf phenology
Soil type, topographic position and fertilization
Distance from the tree
Influence on yield components
Influence on cotton
Influence on groundnuts

Vitellaria paradoxa, Parkia biglobosa and other species with typical leaf phenology
Soil type
Influence on groundnuts and cotton
Distinctions between tree species

Cardinal directions
Tree size

Parkland tree density and ‘parkland effect’

Influence of trees on microclimate
Light interception
Evapotranspiration and soil moisture

Seasonal variations in soil moisture
Soil moisture variations according to tree size

Air humidity
Influence of trees on species composition
Influence of trees on phenology



Parkland management practices
Assisted tree regeneration
Planting of parkland species
Improved fallows
Fire protection

Silvicultural techniques
Coppicing and pollarding
Tree fertilization

Management techniques for improved crop production
Pruning and coppicing
Organic fertilization and mulching
Tree/crop associations

Genetic improvement of parkland species

Management and conservation of parkland genetic resources




Traditional tenure of agricultural land
Socio-economic organization and land allocation
Modes of access to land
Land borrowing
Traditional versus state tenure security

Indigenous institutions regulating the management of parkland resources
Regulating use by outsiders
Regulating use within communities
Changing traditions

Constraints and opportunities in traditional tree tenure
Traditional rights to parkland trees on inherited land
Tree-planting on borrowed land
Commoditization of land and trees
Women's rights
Implications of traditional tenure regimes

Impact of State policy on parkland management
Forestry legislation in the Sahel
Ambiguities in forest codes
Inappropriate rules
Institutional structure
Farmers' perceptions of their rights
The neglect of pastoral practices in land policies
Implications for improved parkland management

Control of forest commons

Local participation in the fuelwood sector



Production of parkland trees
Fruit production
Foliage production
Gum production
Wood production



Food security
Quantitative aspects of consumption
Qualitative contribution of parkland foods

Nutritional quality
Food variety
Seasonal food balance

Health care

Economic importance of parkland products at the local level
Diversity of products
Market volume and income

Parkland products of international economic importance
Gum arabic
Vitellaria paradoxa

General description
Market constraints
International market opportunities

Social differentiation in NTFP activities

Socio-cultural and spiritual values of parkland products

Analysis of costs and benefits of parkland production



The significance of agroforestry parklands

Dynamic systems

Parkland classification

Conservation and reproduction of agroforestry parklands

Biophysical interactions

A landscape with a future



1.1Methods for assessing parkland resources
1.2Comparative tree growth in parkland and natural woodland conditions
1.3Ethnic distinctions in land-use patterns: the case of the Lobi, Bwa and Mossi in Burkina Faso
1.4Ethnic distinctions in land-use patterns: the case of the Sérer and Wolof in Senegal
2.1Parkland regeneration in seasonally flooded areas
2.2Processing and marketing incentives for the conservation and utilization of parkland trees: the case of Vitellaria in Uganda and Parkia in Senegal
3.1Influence of parkland trees on soil texture
3.2Pruning modifies Faidherbia albida's reverse foliation patterns
3.3Experimental designs for assessing the influence of trees on crop production
3.4How much do parkland tree canopies reduce sunlight intensity?
3.5Wind speed reduction in agroforestry parklands
3.6Rainfall interception by parkland trees
4.1Advances in the vegetative propagation of some parkland species
4.2Is there a case for improvement of Vitellaria paradoxa?
4.3Basic information needs for in situ conservation of intraspecific genetic diversity
5.1Categories of rights comprising tree tenure
5.2At what cost a permit?
7.1Opportunities for growth in the domestic market for Vitellaria paradoxa
7.2Cosmetics sector demand for Vitellaria paradoxa


1.1Distribution and types of farmed parkland in western Senegal
1.2Distribution of Faidherbia albida
1.3Densities of Faidherbia albida in western Senegal
1.4Flowering Vitellaria paradoxa, Sankpala, Ghana
1.5Distribution of Vitellaria paradoxa subsp. paradoxa and V. paradoxa subsp. nilotica in relation to mean annual rainfall
1.6Distribution of Parkia biglobosa in relation to mean annual rainfall
1.7Distribution of Adansonia digitata in Africa and neighbouring areas
1.8Adansonia digitata parklands, Senegal
1.9Distribution of Balanites aegyptiaca in relation to mean annual rainfall.
1.10Cordyla pinnata fruit, Nioro du Rip, Senegal
1.11Borassus aethiopum parklands, Senegal
1.12Faidherbia albida parklands around Dolekaha, Côte d'lvoire. Monospecific stands of F. albida are located almost exclusively in a belt around the village, while Vitellaria paradoxa and Parkia biglobosa parklands are located at a greater distance. Note sacred forest in lower right hand corner.
2.1‘Construction’ of a Borassus flabellifer parkland, Banfora, Burkina Faso
2.2Peulh herders let cattle browse pruned Faidherbia albida branches before piling and collecting the wood
2.3Azadirachta indica invasion around Faidherbia albida trees in Dossi, Burkina Faso
2.4Fruit of Vitellaria paradoxa ssp. nilotica held by a farmer participant of the Shea (Yao) project in Lira, northern Uganda
2.5The COVOL (Cooperative Office for Voluntary Organizations of Uganda) hand press for extracting shea oil, Lira, Uganda
2.6Oxen traction for sowing cotton in Parkia biglobosa parklands, Dolekaha, Côte d'lvoire
2.7Mechanized cultivation in Vitellaria paradoxa parklands, Bole, Ghana. Note lack of woody regeneration.
3.1Vitellaria paradoxa (right) and Parkia biglobosa (left) parkland in the Bassila region of Benin
3.2Crop and clearing residues are gathered and burned before the next agricultural season
3.3Cattle grazing on Prosopis africana pods in cotton fields, Holom, northern Cameroon
3.4Faidherbia albida parklands are a significant source of fuelwood, especially where trees are regularly pruned
3.5Vitellaria paradoxa parkland in the dry season, Thiougou, southern Burkina Faso
4.1Vitellaria paradoxa subsp. nilotica regeneration being actively protected in a house field, Adwari, Uganda
4.2Expansion of Borassus aethiopum parkland through active regeneration (foreground)
4.3Naturally regenerated stand of Vitellaria paradoxa following protection from fire and cultivation, Tolon, Ghana
4.4Lopping of Faidherbia albida, Ngaparou, Senegal
4.5Pollarded Azadirachta indica among Faidherbia albida trees in village fields of Dissin, Yoba Province, Burkina Faso
4.6Faidherbia albida parkland with substratum of Ziziphus mauritiana trees, Yagoua, Cameroon
4.7Manure or compost is heaped and will be spread uniformly throughout the fields
4.8Association of a local tuber crop, ‘fabirama’, with a Parkia biglobosa canopy, Thiougou, Burkina Faso
4.9Rooted hardwood cutting of Vitellaria paradoxa with new flower bud formation
4.10‘Timber’ variety of Vitellaria paradoxa growing in cleared woodland, Bomburi, Ghana
4.11‘Erect’ variety of Vitellaria paradoxa in farmed parklands, Sawla, Ghana
4.12‘Dwarf’ variety of Vitellaria paradoxa with fruit in farmed parklands, Tolon, Ghana
4.13Bombax costatum branches trimmed to harvest the flowers for use in a highly appreciated sauce, with negative consequences for regeneration
4.14Adansonia digitata flower visited by a bat. Bats play a significant role in the pollination of several parkland species
5.1The fibres extracted by these young women from palm petioles will be used to make ropes and baskets
5.2Harvesting of young leaves from a small Adansonia digitata tree, Burkina Faso
5.3Harvesting pods of Parkia biglobosa, Benin
5.4Man collecting Borassus aethiopum fruit
5.5Collecting Borassus aethiopum sap to make wine
5.6A woodworker finishes a traditional mortar used for pounding various foods. Wood for such items often comes from agroforestry parklands
5.7Women bringing home fuelwood
5.8Cattle herded through Faidherbia albida parklands
5.9Canoe hollowed out from a Prosopis africana trunk, Bec de Canard, Cameroon
5.10Blacksmiths using charcoal from Prosopis africana, Maroua, Cameroon
6.1Weighing pod production of a single Parkia biglobosa tree, Thiougou, Burkina Faso
6.2Juicy fruit of Lannea microcarpa are an energy-rich snack f or children in the dry season, Thiougou, Burkina Faso
6.3Borassus aethiopum leaves are collected for use in basket-making
6.4Gum arabic oozing from an Acacia senegal tree, Barkedji, Senegal
6.5Wood gathered to build a drying rack for millet, Holom, northern Cameroon
7.1Parkia biglobosa products: fermented ‘soumbala’ (front), cleaned seeds (middle), yellow pulp (back)
7.2Adansonia digitata fruit: the pulp is used as a flavouring in a variety of cool and hot drinks
7.3Flowers and calyces of Bombax costatum used for making a glutinous red sauce
7.4Tamarind pods and balls of pods with the husks removed for storage and sale
7.5Various commercial items manufactured by Phycos, a local company in Burkina Faso specializing in cosmetic products made from Vitellaria butter
7.6While other ethnic groups sun-dry Vitellaria nuts, the Otamari in Diepani, Benin, use ovens. The method requires a lot of fuelwood but allows women to leave the nuts almost unattended for the two-three days required.
7.7A ‘dero’, the traditional local granary with walls made of a dried clay and straw mixture, provides excellent long-term storage for Vitellaria nuts in Lira, Uganda
7.8After shelling, Vitellaria kernels are quickly roasted and then coarsely pounded (foreground). The product is then ground to produce a chocolate-like paste (background), Thiougou, Burkina Faso. The paste will then be mixed vigorously with first hot and then cold water to separate out the solid white fat.
7.9The white Vitellaria fat is washed several times and then shaped into different forms, depending on the region. The Peulh near Bassila, Benin, use small calebashes to make butter pats, sold here together with some whole Vitellaria fruit gathered on the way to market.
7.10The social importance of trees is not always recognized. Meetings often take place in the shade of large, conspicuous village trees.
7.11Cool shady conditions provided by large tree canopies are ideal for rural Sahelian markets
7.12Marketing traditional soap made from palm kernel oil and ash, Bassila, Benin
7.13Marketing Faidherbia albida pods in Mopti, Mali
7.14Young girl selling Adansonia digitata leaves
7.15Boiled Borassus aethiopum seedlings for sale


1.1Scientific, English and French names of common parkland trees
1.2Dominant species in West African parklands by climatic zone
1.3Densities of Faidherbia albida in agroforestry parklands
1.4Densities of Vitellaria paradoxa in agroforestry parklands
1.5Densities of Parkia biglobosa in agroforestry parklands
1.6Main productive functions fulfilled by agroforestry parklands
3.1Improvement (%) of soil nutrient content under Faidherbia albida canopies compared to controls in the open
3.2Crop yields under and outside Faidherbia albida canopies
3.3Impact of Vitellaria paradoxa and Parkia biglobosa on sub-canopy crop yields (%)
6.1Fruit production in Vitellaria paradoxa
6.2Pod production in pruned and unpruned Faidherbia albida trees
7.1Food value of some non-timber parkland products
7.2Products and uses of common parkland trees