Study of Floristic Diversity and the Structural Dynamics of Some Species Providers of Non Woody Forest Products in the Vegetable Formations of the Centre East of Burkina Faso
The goal of this study is to contribute to a better knowledge of certain species providing Non Woody Forest Products (NWFP) in the Centre East of Burkina Faso. This study aims to determine the state of the resources in Vitellaria paradoxa, Balanites aegyptiaca, Tamarindus indica and Lannea microcarpa. For this purpose, an inventory of the vegetation was carried out in circular pieces of land of 1250 m2, as a sample of the zone of work, based on the chart of occupation of the grounds. We are identified 158 species comprising 90 genera and 47 families. Those species represent more than 90% of the trees from which various parts are used in food, traditional pharmacopeia and the craft industry. We also showed that because of the strong anthropisation of the zone, the bad pedoclimatic conditions and the permanent bush fires, the regeneration and growth of Vitellaria paradoxa, Balanites aegyptiaca, Tamarindus indica and Lannea microcarpa are disturbed.
to cite this article:
J.M.K. Ky, C. Gnoula, P. Zerbo, J. Simpore, J.B. Nikiema, A. Canini and J. Millogo-Rasolodimby, 2009. Study of Floristic Diversity and the Structural Dynamics of Some Species Providers of Non Woody Forest Products in the Vegetable Formations of the Centre East of Burkina Faso. Pakistan Journal of Biological Sciences, 12: 1004-1011.
Forest products constitute an important source of income for the rural populations
of Burkina Faso. Therefore, the component environment is a strategic axis in
the implementation of the Strategic Framework of Fight against Poverty in Burkina
Faso (Burkina Faso Ministry of Economy and Development, 2004).
Forest installations, initially focussed on the production and exploitation
of high commercial value wood (Marshall and Newton, 2003)
did not take into account the economic importance of other tree products. However,
certain products formerly described as sub-products or secondary products play
important socio-economic roles as much as wood itself (Anderson
and Farrington, 1996; FAO, 1995). It is the case of
Vitellaria paradoxa, Balanites aegyptiaca, Tamarindus indica,
Adansonia digitata and Lannea microcarpa. However, the exploitation
of these resources remains artisanal with an uncontrolled management (Sunderland
and Ndoye, 2004). Perceived as a gift of nature, these woody phytogenetic
resources were not under any rules of durable management in rural areas in Burkina
Faso. However, the influence of human activities on the dynamics of vegetation
and ecosystems evolves with demographic growth and constitutes a threat for
the survival of many utility species (Lykke et al.,
1999; Backer et al., 2004). Thus, the perenniality
of these species is compromised in certain formations of vegetation and particularly
in tree savannas, shrubby savannas and fields. In fact the vegetation of Burkina
Faso which is dominated (up to 2/3) by the formations of the savannas (Paré,
2008), is still undergoes deep structural and floristic changes because
of anthropic pressures and recurring droughts (Lindqvist
and Tengberg, 1993; Gijsbers et al., 1994;
Agnew and Chappell, 2000). This results in an accentuation
of the phenomenon of desertification, involving a higher mortality rate of woody
species and a degradation of the vegetation (Baumer, 1994;
Ræbild et al., 2007; Wittig
et al., 2007). However, the diversity and the structure of the vegetation
constitute indicators of the quantitative and qualitative evolution of the cover
of vegetation (Millogo-Rasolodimby and Guinko, 2006).
Therefore, the purpose of the present study is to determine the floristic diversity
and structural dynamics of species providers of non woody forest Products in
two types of savannas and fields in the Centre East of Burkina Faso.
MATERIAL AND METHODS
The zone of study: The studied zone is a protected area located between the communes of Bissiga and Tenkodogo (Province of Boulgou) and Lalgaye (Province of Koulpélogho) in the Eastern Centre Region of Burkina Faso. This zone is at 325 km from Ouagadougou the capital of Burkina Faso in the East on the National Road Tenkodogo Ouargaye at 30 km from Tenkodogo and 12 km from Ouargaye. This zone covers 30 ha (Fig. 1).
The Eastern Centre Region of Burkina Faso has been created by law n°2001-013
of July 2, 2001 in Burkina and is located between 1°0' of longitude west
and 0°45' of longitude East, between 12°35' and 10°55' of latitude
north. This zone which is a frontier of Togo and Ghana covers a surface of 14656
km2. On the administrative level, it includes 3 Provinces, 30 communes
including 6 urban communes and 24 rural communes with 711 villages. Its population
amounted to 1.132.023 inhabitants in 2006 including 946.065 living in rural
areas. It represented 8.24% of the total population of the country in 2006 according
to Ministère de lEconomie et des Finances, Institut
National de la Statistique et de la Démographie (2007) and the principal
ethnic groups are the Bissa, Mossi, Yanna, Peulhs and Koussassé. It is
an area of reception of migrants (54.435 migrants in 2006). The climate is a
Soudano-Sahelian type, ranging between isohyets 800 and 1000 mm and it belongs
to the climates of savannas and is characterized by a contrast between one season
of rains of a few months and a long dry season. The annual average temperature
is 33°C and can reach a maximum of 41°C. We can distinguish one fresh
period from November to February and a hot period from March to May.
The methodology of inventory is mainly based on the systematic inventory with
the point quadrat method (Lanly, 1981; De
Vries, 1986; Schreuder et al., 1987; Shiver
and Borders, 1996). It focused on units of small land on a sample elaborated
from a map of occupation of the grounds (Bazoun, 2007).
These units of small land distributed in the various formations of vegetation
are circular with 19,95 m of ray and a surface of 1250 m2 as recommended
size in inventory for the countries of French-speaking Africa in the North of
the equator including Burkina Faso (Kaboré, 2007;
Sylla and Picard, 2005) (Fig. 2). This
inventory has been realized from 15th October to 10th November 2007. This period
is appropriate for the phenological study of the vegetation, this allowed to
the identification of species.
|| Map of localization of squares in the Center East of Burkina
|| Sample design
For each type of vegetation, the research carried out gave for tree savannas 15 surveys on a surface of 1.875 ha, for shrubby savannas, 33 surveys on 4.125 ha and for fields 48 surveys on 6 ha, respectively accounting for 13.9, 30.5 and 44.4% of the total surface inventoried.
The material used is composed of GPS, compasses, ribbon metres, ropes and machetes.
The inventory concerned individual plants with height ranking above 1.30 m.
In each survey account, the list of woody and herbaceous species is drawn up.
The statements related to the diameter at chest level (1.30 m), the height,
the health condition, the ground, the anthropic disturbances and phenology.
Regenerations were noted on the whole of these small squares. The data were
collected on inventory cards and the species were identified from the flora
and lexicons (Von Maydel, 1986; Arbonnier,
2000; Bosch et al., 2002).
The vegetation of the zone of study consisted of 158 species comprising 90 genera and 47 families. The woody species accounted for 41% of the listed species. The species providing NWFP constitute more than 90% of the trees from which various parts (fruits, sheets, bark, root, flowers and latex) are used in human consumption, animal feed, human and veterinary pharmacopeia and in handicraft industry. The majority of plants species listed, 75%, are in the tree savannas, shrubby savannas and fields (Table 1). The species most used as NWFP are Vitellaria paradoxa, Balanites aegyptiaca, Tamarindus indica, Lannea microcrapa and Adansonia digitata.
More than 85% of the inventoried vegetation is in good health condition, 14%
of the trees are cut or sick. Nearly all the vegetation is subjected to bush
fires and the pasturage of animals (Fig. 3a-d,
Woody savanna: In this vegetation the repartition in classes of diameters
presents the bell-shaped or J-shaped species. More than 95% of the species are
less than 15 m high. Individuals with height ranging from 0 to 2 m account for
0% for Vitellaria paradoxa and Lannea microcarpa whereas
it reaches 20 to 40% for Tamarindus indica and Balanites aegyptiaca.
Individuals with the topreaching 15 m of height are between 0 to 10%. In tree
savannas Vitellaria paradoxa have the highest density (46 feet ha-1)
followed by Balanites aegyptiaca (21 feet ha-1) and then come
Lannea microcarpa and Tamarindus inidica which is the least dense
species (Table 2). Vitellaria paradoxa is also the
most frequent (8.57%) followed by Lannea microcarpa then come Balanites
aegyptiaca and Tamarindus indica (Table 3).
Relative abundance is higher for Vitellaria paradoxa followed by Tamarindus
indica, then come Balanites aegyptiaca and Lannea microcarpa
Shrubby savannas: In this vegetable formation the classes of diameters
are characterized by bell-shaped histograms for the whole of the species except
Lannea microcarpa which presents a sequenced form in L. As for the 4
species, more than 97% of the individuals have a height ranging from 2 to 15
m. Below 2 m and beyond 15 m the individuals are less represented and account
for 2 to 3% (Fig. 4-6). In shrubby savannas
Vitellaria paradoxa is denser (29 feet/ha) and is followed by Tamarindus
indica, Lannea microcarpa and Balanites aegyptiaca (Table
2). Lannea microcarpa is the most frequent species (20%) followed
by Balanites aegyptiaca (15.71%), Vitellaria paradoxa (11.42%)
and Tamarindus indica (Table 3).
|| (a) Balanites aegyptiaca, (b) Vitellaria paradoxa,
(c) Tamarindus india when flowering and (d) Lannea microcarpa
half-compartment during clearing
||Distribution of diameter classes of 4 species in a wooded
savannah vegetation. (a) Vitellaria paradoxa, (b) Balanites aegyptiace,
(c) Tamarindus indica and (d) Lannea microcarpa
||Distribution of diameter classes of 4 species in a shrubby
savannah vegetation. (a) Balanites aegyptiaca, (b) Vitellaria
paradoxa, (c) Tamarindus indica and (d) Lannea microcarpa
||Distribution of diameter classes of 4 species per fields.
(a) Vitellaria paradoxa, (b) Balanites aegyptiaca, (c)
Tamarindus indica and (d) Lannea microcarpa. CD: Classifies diameter
(cm). CD1 = 1à5; CD2 = 6 to 10; CD3 = 11 à15; CD4 = 16 to
20; CD5 = 21 to 25; CD6 = 26 to 30; CD7 = 31 to 35; CD8 = 36 to 40; CD9
= more than 40
As for the abundance of species in shrubby savannas, it is dominated by Vitellara
paradoxa followed by Lannea micropcarpa and Balanites aegyptiaca
then by Tamarindus indica (Fig. 5a-d).
|| Repartition of the families by type of vegetable formation
|Bold values are in dark-studied vegetable formations
|| Specific density by species and vegetable formation
|| Frequency of the various species by vegetable formation
Fields: The classes of diameters present bell-shaped histograms for Vitellaria paradoxa and Tamarindus indica. The form is J for Lannea micrcarpa and L for Balanites aegyptiaca.
The heights of the trees in the fields lie between 2 and 15 m. The individuals having a height ranging between 5 and 15 m are the most represented (65 to 90%). Young trees ranging between 1 and 5 m of height are very slightly represented.
In the fields, Vitellaria paradoxa has the highest density (25 feet
ha-1), followed by Lannea microcarpa, Balanites aegyptiaca
and Tamarindus indica (Table 2). Vitellaria paradoxa
is also the most frequent species (more than 24%) followed by Balanites
aegyptiaca and Lannea microcarpa and Tamarindus indica (Table
3). In term of abundance Vitellaria paradoxa is more abundant in
the zone followed by Balanites aegyptiaca and Lannea microcarpa
which have almost the same abundance and finally by Tamarindus indica (Fig.
Overall abundance, density and frequency of species providers of non woody
forest product are in irregular evolution as indicated by the shapes of diameter
growth in the three types of studied vegetation. Therefore, in woody and shrubby
savannas as in fields, all the species and the vegetation structure are disturbed
(Williams et al., 1996). Vitellaria paradoxa
is dominating in terms of abundance, as well as frequency and density except
in shrubby savannas where Lannea microcarpa is more frequent. This is
confirmed by (Kéré, 1998), who showed that
savannas in the Sudanian Sector are mainly dominated by Vitellaria paradoxa.
That can be explain by the fact that the populations has preserved as much
as possible the most utile species and particularly Vitellaria paradoxa
(Boffa, 1999, 2000) The spacing
out in the repartition of bell-shaped and J-shaped classes of diameters reveal
ageing populations for Vitellaria paradoxa and Tamarindus indica what
shows the irregular evolution of these species (Skarpe,
1990). Indeed in the various types of the vegetation and specifically in
the fields, these very utility species have a very low capacity of regeneration
according to Dupriez and Leener (1998) and present subjects
of large diameters withheights often rising above 15 m and can even reach 20
m. This is the result of the particular care that the populations bring to these
species because of their obvious socio economic interest (Boffa,
1999; Devineau et al., 2009). Vitellaria
paradoxa and Tamarindus indica are the main species used by the populations
of the zone either for their needs (family consumption) or for marketing. The
effects of ploughings and their protection against animals and bush fires have
a beneficial influence on the species in the fields in terms of growth in diameter,
height and productivity as indicated by (Boffa, 2000).
In shrubby savannas Balanites aegyptiaca presents a regular growth and
evolution in spite of the disturbances noticed in most species. This species
grows particularly on old ferric soils. In the same way the frequency of Lannea
microcarpa in this vegetable formation due to the fact that groupings of
Lannea microcarpa characterize shrubby savannas in association with Acacia
machrostachya and Cassa sieberiana. Lannea microcarpa is well distributed
in shrubby savannas but this species meets problems of growth in strongly anthropized
zones; such is the case in our zone of study. The aging of this species might
be caused by the intensive and uncontrolled exploitation for human and animal,
by clearings for the installations of news fileds and by the bush fires, the
attacks of animals, the conditions of station (Kéré,
1998; Ouédraogo et al., 2006) but also
by the destruction of the young seedlings during the clearings and with the
abusive cutting of trees for various needs. According to present observations
Balanites aegyptiaca is better regenerated in shrubby and less inn woody
savannas. There is very little regeneration for Vitellaria paradoxa because
they are destroyed by fires, droughts and clearings. Tamarindus indica presents
less young individuals and an nearly non-existent regeneration. Although, in
the Sudanian, formations the potential of regeneration exists (Gijsbers
et al., 1994). Vitellara paradoxa, Balanites aegyptiaca,
Tamarindus indica and Lannea microcarpa, regenerate badly except
for Balanites aegyptiaca in certain parts of shrubby savannas. This is
due to the anthropic pressions, bush fires, animals and to the conditions of
the station as noted by Kéré (1998). It
is also due to the destruction of young seedlings during the clearings and with
the abusive cutting of trees for various needs.
The bell-shaped structures or J indicate that in savannas, shrubs and fields,
species evolve abnormally (Scholes, 2002). Indeed, there
is little regeneration and aging vegetation. With the exception of Vitellaria
paradoxa, young plants are cut, burned or overfished. We note that in shrubby
savannas, species are better conserved and evolve more regularly than in fields
and wooded savannas especially for Balanites aegyptiaca, Lannea microcarpa
and to a lesser extent for Vitellaria paradoxa. For Vitellaria paradoxa,
the structure of diameter classes has an L-form which means, according to the
Scientific Council for Africa (CSA), a normal development of the forestry point
Though, characterized by a strong demographic growth, the area of the Centre
East of Burkina Faso is rich in cash providers of NWFP with an important potential
which is a socio economic asset for the country. In the study area Vitellaria
paradoxa, Balanites aegyptiaca, Tamarinus indica and Lannea
microcarpa have an evolution characterized by a lack of regeneration, inhibited
growth and aging of populations. This potential is increasingly prone to very
strong anthropic pressures and an uncontrolled exploitation which, could compromise
the regeneration of these species and their perenniality, destroy one of the
principal sources of additional income for the rural populations. The intensive
and uncontrolled exploitation of species providers of NWFP, climatic risks and
bush fires cause damage and prejudice to the woody phytogenetic resources and
contribute to their rarefaction with a risk to see them disappearing. The study
of the floristic composition as well as that of the structure of the vegetation
reveal a weak regeneration of the principal species providers of NWFP such as
Vitellaria paradoxa, Tamarindus indica, Lannea microcarpa
and Balanites aegyptiaca. These species are disturbed in their regeneration
and their growth. The large trees we meet in the fields and savannas could not
be replaced if measures of conservation and restoration are not undertaken.
In the same way, the installation of new fields, the exploitation of the non
woody forest products, the non-organization of the actors of NWFP and the absence
of a concerted management plan constitute considerable constraints for the perpetuation
of resource providers of NWFP. It is necessary for a better management of these
resources to develop strategies of conservation and durable management which
would involve all the actors by implementing the agro forestrytechniques of
1: Agnew, C.T. and A. Chappell, 2000. Drought in the sahel. Geo J., 48: 299-311.
2: Anderson, J. and J. Farrington, 1996. Forestry extension: Facing the challenges of today and tomorow. Unasylva, 184: 3-12.
3: Arbonnier, M., 2000. Trees, Shrubs and Lianas of West African Dry Zones. Margraf Publishers, Paris, pp: 574.
4: Backer, D.M., S.E. Jensen and G.R. McPherson, 2004. Impacts of fire-suppression activities on natural communities. Conserv. Biol., 18: 937-946.
5: Baumer, M., 1994. Forêts-parcs ou parcs arbores? Bois Forêts des Tropiques, 240: 53-67.
6: Bazoun J., 2007. La base de donnees de l`occupation des terres (BDOT), un outil d`aide à la decision pour le developpement durable au BURKINA FASO. Proceedings of the UN/Morocco/ESA/International Workshop on the Use of Space Technology for Sustainable Development, Apr. 25-27, Rabat, Morocco, pp: 1-19.
7: Boffa, J.M., 1999. Agroforestry Parklands in Sub-Saharan Africa FAO Conservation Guide 34. Springer, Netherlands, pp: 169-170.
8: Boffa, J.M.J., 2000. The agro forestry parks in sub-Saharan Africa. Books FAO Conservation 34. pp: 258.
9: Bosch, C.H., J.S. Siemonsma, R.H.M. Lemmens and L.P.A. Oyen, 2002. Vegetable Resources of the Tropical Africa: Species Basic List and Commodity Groupings. PROTA Foundation, Wageningen, The Netherlands, pp: 314.
10: Burkina Faso Ministry of Economy and Development, 2004. Strategic Framework of Fight Against Poverty. Burkina Faso, Ouagadougou, pp: 137.
11: Kere, U., 1998. Vegetation and use of Wild Plants in the Region Tenkodogo (Burkina Faso). In: Etudes Sur La Flore et La Végétation Du Burkina Faso et Des Pays Avoisinantes, Wittig, R. and S. Guinko (Eds.). Vol. 4, Frankfurt, Ouagadougou, pp: 3-55.
12: Devineau, J.L., A. Fournier and S. Nignan, 2009. Ordinary biodiversity in Western Burkina Faso (West Africa): What vegetation do the state forests conserve? Biodiversity Conservat., 18: 2075-2099.
CrossRef | Direct Link |
13: De Vries, P.G., 1986. Sampling Theory for Forest Inventory A Teach Yourself Course. Springer Verlag, Berlin.
14: Dupriez, H. and P. de Leener, 1998. Trees and Multistorey Agriculture in Africa: A Textbook for Agroforestry. CTA, Wageningen, The Netherlands pp: 280.
15: FAO, 1995. Non-wood Forest Products for Rural Income and Sustainable Forestry. FAO, Rome, Italy.
16: Gijsbers, H.J.M., J.J. Kessler and M.K. Knevel, 1994. Dynamic and natural regeneration off woody species in farmed parklands in the Sahelian area (Province off Passore, Burkina Faso). For. Ecol. Manage., 64: 1-12.
17: Kaboré, C., 2007. Test d’applicabilité de méthodes d’inventaire forestier rapides au Burkina Faso. Ministère de l’Environnement et du Cadre de Vie/Direction du Suivi Ecologique. pp: 39.
18: Wittig, R. and S. Guinko, 1998. Etudes sur la flore et la végétation du Burkina Faso et des pays avoisinants. Studien zur Flora und Vegetation von Burkina Faso und seinen Nachbarländern; Bd. IV. Solingen (Verlag Natur and Wissenschaft).
19: Lanly, J.P., 1981. Manuel d'inventaire forestier, avec références particulières aux forêts tropicales hétérogènes. Études FAO: Forêts 27, FAO, Rome, Italie.
20: Lindqvist, S. and A. Tengberg, 1993. New evidence of desertification from case studies in Northern Burkina Faso. Geografiska Annaler Ser. A Phys. Geogr., 75: 127-135.
Direct Link |
21: Lykke, A.M., 1998. Assessment off species composition off changes in savannas vegetation by means woody seedlings' size class distribution and local information. Biodiversdity Conserv., 7: 1261-1275.
22: Lykke, A.M., B. Fog and J.E. Madsen, 1999. Woody vegetation exchanges in the Sahel off Burkina Faso assessed by means of local knowledge, aerial photographs and botanical investigations. Geographisk Tidsskift, Danish Newspaper Geogr., 2: 57-68.
23: Marshall, E. and A.C. Newton, 2003. Non-timber forest products in the community of El Terrero, Sierra de Manantlan Biosphere Reserve, Mexico: Is their use sustainable? Econ. Bot. Plant Sci., 61: 113-152.
Direct Link |
24: Millogo-Rasolodimby, J. and S. Guinko, 2006. Les plantes ligneuses spontanées à usages culinaires au Burkina Faso. Berichte des Sonderforschungsbereichs 268, Band 7, Frankfurt am 1996: 125-133.
25: Ministère de l’Economie et des Finances Institut National de la Statistique et de la Démographie, 2007. Recensement Général de la population et de l’habitat. Rapport définitif.
26: Ouédraogo A., A. Thiombiano, K.Hahn-Hadjali, S. Guinko, 2006. Diagnostic de l’état de dégradation des peuplements de quatre espèces ligneuses en zone soudanienne du Burkina Faso. Science et Changements Planétaires/Sécheresse. Volume 17, Numéro 4, 485-91, Octobre-Novembre-Décembre 2006, Article Scientifique.
27: Paré, S., 2008. Land use dynamics, tree diversity and local perception of dry forest decline in Southern Burkina Faso, West Africa. Faculty of Forest SciencesDepartment of Forest Genetics and Plant PhysiologyUme.
28: Ræbild, A., H.H. Hansen, J. Dartell, J.M. Kiley Ky and L. Sanou, 2007. Ethnicity land use and woody vegetation a case study from South-Western Burkina Faso. Agrofor. Syst., 70: 157-167.
Direct Link |
29: Scholes, R.J., P.R. Dowty, K. Caylor, D.A.B. Parsons, P.G.H. Frost and H.H. Shugart, 2002. Trends in savanna structure and composition along an aridity gradient in the Kalahari. J. Vegetation Sci., 13: 419-428.
Direct Link |
30: Schreuder, H.T., S.G. Banyard and G.E. Brink, 1987. Comparison of three sampling methods in estimating stand parameters for a tropical forest. For. Ecol. Manage., 21: 119-128.
31: Shiver, B.D. and B.E. Borders, 1996. Sampling Techniques for Forest RessourceInventory. Wiley and Sons, New York.
32: Skarpe, C., 1990. Structure of the woody vegetation in disturbed and undisturbed arid savanna, Botswana. Plant Ecol., 87: 11-18.
Direct Link |
33: Sylla, M. and N. Picard, 2005. Guide méthodologique des évaluations rapides de bois énergie. HAL: Cirad-00147063, Version 1. Science du Vivant/Ecologie, Environnement, pp: 90.
34: Sunderland T. and O. Ndoye, 2004. Forest Products, Livelihoods and Conservation. Case Studies of Non-Timber Forest Product Systems. Vol. 2, Center for International Forestry Research, Bogor, Indonesia,.
35: Von Maydel, H.J., 1986. Trees and Shrubs of the Sahel. Verlag Josef Margraf, Weikersheim, Germany.
36: Williams, R.J., G.A. Duff, D.M.J.S. Bowman and G.D. Cook, 1996. Variation in the composition and structure of tropical savannas as a function of rainfall and soil texture along a large-scale climatic gradient in the Northern Territory, Australia. J. Biogeogr., 23: 747-756.
Direct Link |
37: Wittig, R., K.M. Schmidt and J. Szarzynski, 2007. A study of climate change and anthropogenic impacts in West Africa. Environ. Sci. Pollut. Res., 14: 182-189.
Direct Link |