Book – Protection de la Nature en Afrique de l’Ouest : Une Liste Rouge pour le Bénin. Nature Conservation in West Africa : Red List for Benin.

Protection de la Nature en Afrique de l’Ouest : Une Liste Rouge pour le Bénin. Nature Conservation in West Africa : Red List for Benin.

Neuenschwander, P., Sinsin, B. & Goergen, G. (eds). 2011. International Institute of Tropical Agriculture, Ibadan, Nigeria. 365 pages. ISBN : 978 978 49796 9 6.  International Institute of Tropical Agriculture, Ibadan, Nigeria. 365 pages. ISBN : 978 978 49796 9 6

Les informations nécessaires pour la mise en œuvre de la protection de la nature au Bénin sont rares et dispersés. Ce volume pour la première fois prents informations en 33 chapitres couvrant les plantes rares et menacées, les insectes, les poissons, les antilopes, les grands chats, etc. L’état ou plus de 550 espèces est évaluée en fonction des critères de l’UICN, et leurs noms locaux, de courtes descriptions, des écologies et les distributions sont donnés. Le livre est d’un intérêt pour ceux qui travaillent dans la conservation de la nature dans les écoles, les Ong, les touristes à des agences gouvernementales.


Managment and modeling of the transhumance pasture dynamic in a climatic variabilies context in North-East of Benin

PhD Dissertation:

Paolo Lesse (2016). Managment and modeling of the transhumance pasture dynamic  in a climatic variabilies context in North-East of Benin. University of Abomey-Calavi, Laboratoire d’Ecologie Appliquée. 299p

Promotor: Prof. Marcel R. B. HOUINATO.

 

ABSTRACT: Transhumance is a herding system which occupies an important place in the West Africa region and in Benin particularly. This study has been carried out in the North-East Region of Benin which is herders’ predilection area. The general objective of this work is to contribute to a sustainable management of transhumance corridors in the North-East of Benin. The natural corridors have been characterized using linear plots measurements, the method of short cut for the biomass quantification and the phytosociological plots. The herding system has been studied using the system approach. The sensitivity matrix has been used to better assess the vulnerability level of the herders to hydroclimatic variabilities. The future evolution of rainy and thermometric extremes in the basin has been analyzed thanks to the data of the regional climatic model REMO. The Land Change Modeler (LCM) of IDRISI Selva has been used to predict the land occupation state in 2050. The current study allowed bringing out the system constraints. They were feeding, climatic variabilities, legislation, conflict and availability of pastoral infrastructures problems. In total, 162 infrastructures capable of serving as water sources in the study area have been identified but not functional or in a bad state characterized by the inexistence of access trails toward the water points, the presence of abundant vegetables floating on the surface of the waters and the functioning problems of the management mechanisms put in place. Four (04) types of pastures having productivity varying between 3.46 and 5.7 tons of Dry Matter/ha have been identified. The Prosopis africana and Eragrostis atrovirens pasture and the Piliostigma honningii and Stylosanthes fruticosa pasture presented respectively the highest nutritive value for the grass and the legume plants. Twelve (12) transhumance corridors oriented toward the water points and the protected areas have been repertoried and mapped in the study area. About the demographic parameters, the mean annual rate growth is of 1.068 ± 0.05 while the mean production rate is low (0.155 ± 0.02). By the 2050 horizon a contrasted evolution of the rains regimes have been predicted with a mean heating of 1°C. Under the transition probabilities basis, the predictive modeling realized on the land occupation by the horizon 2050 predicted that the tree and shrub savannas will occupy 49.89 % of the total area of the natural North East grassland of Benin Republic. The variability observed is explained by the delay in the beginning of the rains, the bad repartition of the early arrest of the rains, the violent winds. The vulnerability analysis allowed noticing that herding is the most vulnerable and that herders fear more droughts and floods than the rains decreases.

 

  • Lokoli (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Cascade de Tanongou (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Bâtiment Professeur Nestor SOKPON (à droite), bâtiment des volontaires de l'UAC (à gauche). (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • FM Deve (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Musée de Zoologie BIOTA et bâtiment Professeur Mama Adamou N'DIAYE. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Odo Octhèrè (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Système Agroforestier à palmier à huile. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Brousse tigrée (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Système agroforestier à Faidherbia albida. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Vue globale des bâtiments du Laboratoire d’Ecologie Appliquée (LEA). (Photo credit: Dr Akomian Fortuné Azihou / LEA, Octobre 2018)
  • Mare-Bali (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Vue globale des 5 bâtiments du Laboratoire d’Ecologie Appliquée (LEA). (Photo credit: Dr Akomian Fortuné Azihou / LEA, Octobre 2018)
  • Bâtiment Professeur Nestor SOKPON (en haut à gauche), bâtiment des volontaires (en bas à gauche), bâtiment Dr KASSA (à droite). (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Building of the Laboratory of Applied Ecology (LEA). (Credit photo: Dr Akomian Fortuné Azihou / LEA, Abomey-Calavi, Benin, October 2018)
    Building of the Laboratory of Applied Ecology (LEA). (Credit photo: Dr Akomian Fortuné Azihou / LEA, Abomey-Calavi, Benin, October 2018)

Poverty Dynamics and Agricultural Practices for Environment Conservation in African Rural Area: the Case of Adja plateau in Southern Benin

PhD Dissertation:

Emile N. HOUNGBO (2008). Poverty Dynamics and Agricultural Practices for Environment Conservation in African Rural Area: the Case of Adja plateau in Southern Benin. University of Abomey-Calavi, Benin, 309 pages.

Director: Prof. Brice A. SINSIN.

Abstract: The influence of increase in land pressure on agricultural production and the environment is disputed. On one hand the pessimists, mainly represented by MALTHUS (1798), think that land pressure is associated to negative effects on agricultural production and leads to famine, environmental degradation and rural exodus. On the other hand the optimists, mainly represented by BOSERUP (1970), think that land pressure is an essential factor for technological change and agricultural intensification. In fact, although in general the demographic and food evolution in Africa presents a Malthusian trend, like the cases of Yatenga in Burkina Faso, Serer district in Senegal and Adja plateau in Benin Republic, it was even though observed some Boserupian evolutions like the cases of Bamileke district in Cameroon and the district of Machakos in Kenya. One wonders if it’s still possible to presage in Africa a generalised optimistic evolution of BOSERUP (1970) and in which conditions.

This thesis, from a temporal analysis of 122 households on the Adja plateau in the southern Benin, is developing a theoretical intermediary position between MALTHUS theory and that of BOSERUP. It’s demonstrating that in land pressure situation, the farmers’ welfare state was a determinant of improving agricultural practices development and agricultural productivity improvement. Land pressure does not induce ipso facto technological change and agricultural development.

 Theoretical relationship between land pressure and agricultural productivity

 The MALTHUS spectrum and the optimistic vision of BOSERUP represent the extreme situations induced by a higher chronic poverty rate in the first case and a lower chronic poverty rate in the second case. In order that the farmers can develop sustainable agriculture in land pressure situation, it’s necessary to alleviate or eradicate chronic poverty among them by facilitating a truly profitable agriculture.

https://tel.archives-ouvertes.fr/tel-00680042/document

 

 

  • Vue globale des bâtiments du Laboratoire d’Ecologie Appliquée (LEA). (Photo credit: Dr Akomian Fortuné Azihou / LEA, Octobre 2018)
  • Système agroforestier à Faidherbia albida. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Système Agroforestier à palmier à huile. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Bâtiment Professeur Nestor SOKPON (en haut à gauche), bâtiment des volontaires (en bas à gauche), bâtiment Dr KASSA (à droite). (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Brousse tigrée (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Musée de Zoologie BIOTA et bâtiment Professeur Mama Adamou N'DIAYE. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Building of the Laboratory of Applied Ecology (LEA). (Credit photo: Dr Akomian Fortuné Azihou / LEA, Abomey-Calavi, Benin, October 2018)
    Building of the Laboratory of Applied Ecology (LEA). (Credit photo: Dr Akomian Fortuné Azihou / LEA, Abomey-Calavi, Benin, October 2018)
  • Vue globale des 5 bâtiments du Laboratoire d’Ecologie Appliquée (LEA). (Photo credit: Dr Akomian Fortuné Azihou / LEA, Octobre 2018)
  • FM Deve (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Mare-Bali (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Bâtiment Professeur Nestor SOKPON (à droite), bâtiment des volontaires de l'UAC (à gauche). (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Odo Octhèrè (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Lokoli (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Cascade de Tanongou (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)

Analysis of the mode and utilization technologies of palm oil mill wastes and its application for the production of three tropical vegetables (Lycopersicon esculentum, Amaranthus cruentus, Corchorus olitorius) in Southern Benin

PhD Dissertation: 

KOURA Windékpè Tatiana (2015). Analysis of the mode and utilization technologies of palm oil mill wastes and its application for the production of three tropical vegetables (Lycopersicon esculentum, Amaranthus cruentus, Corchorus olitorius) in Southern Benin. Department of Natural Resources Management, Faculty of Agronomic Sciences, University of Abomey Calavi, Benin republic, 252p.

Promotor: Prof. Dr. Ir. SINSIN A. Brice.

Abstract: Owing to the revitalization of the palm oil manufacturing sector in South Benin, some mills are confronted to the problems of waste management although there are many ways these wastes can be reused. To assess how these wastes are managed, waste production systems were determined by numerical classification and considering palm oil production factors and quantities of waste, and characterized through aprincipal component analysis. A semi-structured survey was conducted among 335 oil mills. Four extraction methods (EM) had been identified: traditional (T), improved (I), modern (M) and semi industialized (SI). The amount of wastes generated by each category of oil mill was determined by evaluating that generated by 7 T, 4 I, 4 M and 9 SI oil mills randomly chosen. The study identified four classes of waste production systems: small, medium, large and very large. They produced on average per year 12.4 ± 22 t; 31.3 ± 52.8 t; 132.7 ± 59.1 t and 800.7 ± 418.1t empty fruit bunches; 5.6 ± 10.3 t; 13.6 ± 23.1 t; 135.2 t ± 95.2and 637 ±312.6 t fibers and 15.1 ± 23.7 t; 40.9 ± 28 t; 233.4 ± 172.1 t and 572.6 ± 90.3 t sludge respectively. They were discriminated by the nature and size of plantations, the financial capacity of the mills owners to hirelaborers and the quantities of waste produced. The use of all the amount of generated bunches and fibers did not depend on the quantity produced. Thus, the relationship between the EM improvement andthese wastes management was analyzed. The effect of the EM, the type of waste and their interaction on the calculated indices (user’s percentage, the commercial value, the Rejection Rate, the Importance Value, and the Use Value) were assessed using the log linearly analysis. The fidelity level of each use for each mill was calculated. However, within categories, all mills considered each use at the same level. Whatever theEM, the surplus waste was eliminated either by discharging into the environment or selling. These options were more observed when the EM was improved. Ethnobotanical indexes were used to evaluate the importance and value of palm oil mill wastes in palm oil production areas. A Two Principal Component Analyses was performed to characterize palm oil mill waste uses in link with the production areas. The results showed that the sludge has no importance for mills ‘owners. Oil mills that used the whole amount of bunch and fibers produced were those for which the waste was important for a unique use. The palm oil mill waste contributed more to environmental pollution in Plateau, Couffo and Mono. In order to find immediate solutions to mills facing waste management problems, we proposed solid wastes co-composting and the use of this compost in vegetables production. The analysis of the sustainability of agricultural practices implemented by producers in relation to their knowledge revealed that the use of empty fruits, bunches and fibers depends on producers’ knowledge. These wastes were spread by local application (76.5%) or mulching (33.3%) in plantations or indirectly after composting. Composting is made either by heaping, in combination with pigs breeding or in pits. Composting is a process unknown by 67.5% of mills’ owners. The difference between those who know about it and use it, and those who know about it but do not use it is based on their knowledge of composting advantages. The physico-chemical composition of these wastes were assessed using an ion chromatograph and revealed that these wastes are relatively rich in nutrients except in phosphorus. The co composting of empty fruits bunches and fibers was tested in eighteen bins installed in a split plot design not repeated. Composting method (No shelters (NS) andunder shelter (US)) was the main factor and the type of manure (No manure (NM), poultry manure (PM) and cow dung (CD)) was the secondary factor. As results, the decomposition of wastes and the compost quality obtained varied significantly (p <0.05) with the method of composting and type of manure used. The lowest ratio Carbon/Nitrogen (C/N) 18.38 was obtained in compost where FV were used and made without shelter. The FV had improved the quality of composts in phosphorus content. However, the analysis of leachate revealed high loss of total nitrogen (88.3 ± 12.6mg / l to 146.2 ± 16.4mg / l), potassium (37.2 ± 0.8 to 53.3 ± 1.2 mg / l) and phosphorus (107.9 ± 23.7 to 187.4 ± 65.8mg / L). The high levels of chloride (1301.3 ± 195.8 to 1656.7 ± 147.8 mg / l), biological oxygen demand (3499 ± 425.8 to 6370.7 ±1031.7) shows the need to avoid making the compost heap directly on the ground. The effectiveness of composts was tested with the production of Lycopersicon esculentum, Amaranthus hybridus and Corchorusolitorius were evaluated through a split-split plot design with composting method as the main factor and the types of manure and composts application rates (0t / ha 5t / ha to 10t / ha and 20t / ha) as secondaryfactors. There were 24 treatments and 4 replicates per vegetable. The PM-based compost produced with no shelter (NS) increased amaranth growth and yield (19,2t / ha) compared to others composts. However,in the case of Corchorus olitorius, composts made from waste and CD performed US was recommended. The application of composts increased the yield of Corchorus olitorius and Lycopersicon esculentum from10t / ha.

Keywords: Palm oil mill wastes, waste management, extraction method, type of manure, composting method, vegetables production

  • Odo Octhèrè (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Musée de Zoologie BIOTA et bâtiment Professeur Mama Adamou N'DIAYE. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Mare-Bali (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Bâtiment Professeur Nestor SOKPON (à droite), bâtiment des volontaires de l'UAC (à gauche). (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Building of the Laboratory of Applied Ecology (LEA). (Credit photo: Dr Akomian Fortuné Azihou / LEA, Abomey-Calavi, Benin, October 2018)
    Building of the Laboratory of Applied Ecology (LEA). (Credit photo: Dr Akomian Fortuné Azihou / LEA, Abomey-Calavi, Benin, October 2018)
  • FM Deve (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Système agroforestier à Faidherbia albida. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Vue globale des 5 bâtiments du Laboratoire d’Ecologie Appliquée (LEA). (Photo credit: Dr Akomian Fortuné Azihou / LEA, Octobre 2018)
  • Vue globale des bâtiments du Laboratoire d’Ecologie Appliquée (LEA). (Photo credit: Dr Akomian Fortuné Azihou / LEA, Octobre 2018)
  • Lokoli (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Bâtiment Professeur Nestor SOKPON (en haut à gauche), bâtiment des volontaires (en bas à gauche), bâtiment Dr KASSA (à droite). (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Cascade de Tanongou (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Système Agroforestier à palmier à huile. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Brousse tigrée (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)


Ecology of plant communities in the Biosphere Reserve of Pendjari, BENIN (West Africa)

PhD Dissertation: 

Eméline P.S. ASSEDE (2014). Ecology of plant communities in the Biosphere Reserve of Pendjari, BENIN (West Africa). University of Abomey-Calavi, Bénin. 364 p.

Supervisor : Prof Brice Sinsin.

Abstract: My PhD study provided information and knowledge on the plant communities, plant ecology and population structure of the Biosphere Reserve of Pendjari (BRP). An overview of the flora of the BRP showed that plant species composition of 802 plant species distributed among 428 genera and 102 families, was typical of Sudanian savanna. The recorded endemic species of Benin demonstrated the importance of the reserve for plant conservation.

Two major floristic groups correlated with the gradient of soil moisture (drylands versus wetlands).  Clear differences were shown between wetland plant communities while there were similarities between some dryland plant communities. Soil was one of the determining factors of the distribution of plant associations, and soil moisture was one of the main ecological parameters determining the establishment of species and plant association development. Ferruginous soils, poor in organic matter, are dominated on plateau with clay soils. In wetlands, the soils were a deep silty-clay without gravel.

The analysis of regeneration potential of different vegetation types identified in the BRP reflected the overall structure of the tree layer. Fire as main management tool of the BRP and seed viability explained the dominance of Fabaceae (28.8%) in the regeneration. However topography was a key element in plant establishment. Contrary to the floodplains where soils are poorly drained and poorly aerated, preventing good root penetration, plant regeneration was more important on the border of streams and the hill slopes.

The complexity of the regeneration strategy of plant species and factors controlling that, can also be read through the population structure, as the recruitment of seedlings determines the composition of future populations. A comparative analysis of the population structure of Pseudocedrela kotschyi and Terminalia macroptera in pure and mixed stands indicated that young T. macroptera individuals were predominant in both pure and mixed stands. Trees showed weak density and a random pattern. P. kotschyi young individuals were found to be predominant irrespective of standregime. Trees had a higher density and stronger clumped pattern in pure stands as compared to mixed stands.

The diversity and functional attributes of plants were changed but also recovered after disturbance.The secondary succession in the BRP exhibited a clear floristic pattern with a progressive establishment of the woody vegetation. The first state exhibited the highest species richness with 18.6% of all species exclusive to this state and was characterised by the proliferation of widespread species that disappeared by the third state. About 22% of the 233 species recorded were recorded throughout the fallow cycle. The transition from the first to the second state was characterised by the disappearance of 77% of the total species richness.  Maintenance of a certain state of disturbance is important to maintain total plant diversity in the reserve. Organic matter and the species richness were the best discriminating variables of the succession states. The colonisation of the herb layer by Andropogon gayanus var. bisquamulatus(typical Sudanian species) in the third state can be seen as an indication of a substantial return of soil fertility.

Keys words : Ecology, Vegetation structure, soil properties, Pendjari reserve, Benin

  • Brousse tigrée (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Mare-Bali (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Bâtiment Professeur Nestor SOKPON (à droite), bâtiment des volontaires de l'UAC (à gauche). (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Odo Octhèrè (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Musée de Zoologie BIOTA et bâtiment Professeur Mama Adamou N'DIAYE. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Vue globale des bâtiments du Laboratoire d’Ecologie Appliquée (LEA). (Photo credit: Dr Akomian Fortuné Azihou / LEA, Octobre 2018)
  • FM Deve (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Système Agroforestier à palmier à huile. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Building of the Laboratory of Applied Ecology (LEA). (Credit photo: Dr Akomian Fortuné Azihou / LEA, Abomey-Calavi, Benin, October 2018)
    Building of the Laboratory of Applied Ecology (LEA). (Credit photo: Dr Akomian Fortuné Azihou / LEA, Abomey-Calavi, Benin, October 2018)
  • Vue globale des 5 bâtiments du Laboratoire d’Ecologie Appliquée (LEA). (Photo credit: Dr Akomian Fortuné Azihou / LEA, Octobre 2018)
  • Cascade de Tanongou (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Bâtiment Professeur Nestor SOKPON (en haut à gauche), bâtiment des volontaires (en bas à gauche), bâtiment Dr KASSA (à droite). (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Lokoli (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Système agroforestier à Faidherbia albida. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)


Ecological gap analysis: Assessing the ecological effectiveness of Pendjari Biosphere Reserve in biodiversity conservation in Bénin (West Africa)

PhD Dissertation: 

Dehouegnon Thierry HOUEHANOU (2012). Ecological gap analysis: Assessing the ecological effectiveness of Pendjari Biosphere Reserve in biodiversity conservation in Benin (West Africa). UNIVERSITE OF ABOMEY-CALAVI, Benin. 179 pages.

PhD Promotor: Prof.  Dr. Ir. Brice A. SINSIN.

SUMMARY: Since protected areas are often assumed to be the best way to conserve biodiversity, the current study assessed the ecological effectiveness of Pendjari Biophere Reserve in conservation of some biodiversity targets. In chapter 1 (general introduction) the study’s background, objectives, some theoretical concepts and the thesis structure are presented while Chapter 2 presents the study area Chapter 3 estimates the local preferred uses of three trees target species. Traditional ecological knowledge linked to these species was documented. These species are Afzelia africana Sm., Pterocarpus erinaceus Poir. and Khaya senegalensis (Desv.) A. Juss, multipurpose trees widely used in Africa, yet endangered in their natural environments. The preferred used has been analyzed by means of a cultural importance index. Local ecological knowledge on their conservation was investigated among local people living around Pendjari Biosphere Reserve in Bénin. In total, 160 repondents belonging to four ethnic groups (Gourmantche, Waama, Berba and Peulh) were interviewed in twelve villages. Male and female respondents, aged between 20 and 90 years, were randomly selected in each ethnic group. For each species, a cultural importance index was calculated combining frequency and importance of use. This index allowed us to identify differences in use intensity within and among ethnic groups. Traditional ecological knowledge was tested as a dependent variable of ethnicity. The results showed that A. africana was widely used as medicine, fodder and crafting by most communities, whereas P. erinaceus was the preferred source of fodder for all local people. K. senegalensis was mostly used as medicine and fuel wood by most communities, except by the Peulh who prefer using it as fodder. The use of these trees as source of fuel wood was mostly reported by women while their religious uses were reported by old men from the Gourmantche ethnicity. Medicinal and fodder use of A. africana, fodder use of P. erinaceus and medicinal use of K. senegalensis had the highest overall cultural importance index value. Knowledge relating to local extinction of the target species and their sustainable use varied among socio-cultural groups. These findings have been used so as to propose conservation strategies towards an effective conservation of these tree species. Chapter 4 assesses the effectiveness of the Pendjari Biosphere Reserve to conserve habitat species composition and population structure of A. Africana Sm., P. erinaceus Poir. and K. senegalensis (Desv.) A. Juss. The following two research questions were addressed: (i) do protected habitats of these tree species differ from those unprotected in species composition? (ii) Have population structures (expressed by density and size class distribution) of these tree species been positively affected by this protected area? One hundred and twenty (120) plots were randomly sampled in the protected and surrounding unprotected habitats by inventorying plant species. For the three target species, we measured adult and juvenile, densities and recorded size classes. According to floristic composition four habitat groups were identified in relation to human disturbance, vegetation type, official protection status and moisture. There were protected savannas, unprotected savannas, old fallows and gallery forests. The estimated adult densities of A. africana were similar between protected (13.64 tree/ha) and unprotected savanna (17.44 tree/ha) while for P. erinaceus the adult density was significantly higher in protected (11.74 tree/ha) than in unprotected savanna (4.76 tree/ha). Estimated adult density of K. senegalensis was also significantly higher in protected gallery forest (40.00 tree/ha) than in unprotected one (28.89 tree/ha). Juvenile densities of A. africana, K. senegalensis and P. erinaceus were higher in protected habitats than in unprotected ones but the difference was not significant. In all cases, protected area was effective for maintaining large individuals. Skewness coefficient indicated that populations of investigated trees were declining in their protected habitats. However, the case of A. africana and K. senegalensispopulations seemed to be knocker in the protected area. Our results would suggest PBR to be effective in protecting savanna habitats against fragmentation and it should be required to define and applymanagement strategies for conserving effectively A. africana and K. senegalensis in the protected area in future. In Chapter 5 we assessed the effectiveness of Pendjari Biosphere Reserve to conserve woody species composition, diversity and structure of savannas, the most widespread vegetation type of the study area. The results showed that the two savanna types yielded a total of 58 species representing 44 genera and 23 families with Combretaceae, Mimosoideae, Caesalpinioideae and Rubiaceae as the most abundant families in descending order. However, some species had high Importance Value Index (IVI) in unprotected savanna while others showed the same scheme in protected savanna. Higher values of species richness, Shannon–Wiener’s diversity and Margalef’s index were found in the protected savannas comparatively to the unprotected ones at tree layer level. The number of individuals and the densities were significantly higher in protected savannas compared to the unprotected ones at shrub layer level. As far as the basal area is concerned significant higher values were found in the protected savanna compared to the unprotected one at the two layer levels. From these findings it can be concluded that the effectiveness of PBR to conserve savannas structure and woody diversity depends on the woody layer. However, woody species composition change in relation to savanna conservation status may be also evident according to interrelation specific-use-species. Chapter 6 studied stand structure and spatial distribution of A. africana as helpful to understand its primary seed dispersal mode. Spatial distribution pattern of adult trees and juveniles of the species, spatial relationship between those two life-stages and stand structure were investigated in A. africana dominated savannas. Results showed that A. africana displayed in the Reserve random distribution at large distance scales considering all individuals. However, aggregated distribution was observed at small scale (up to 9 m) in some areas. The adults displayed in all areas a random distribution either at large and small distance scales. The spatial distribution pattern of juveniles followed the same trend of distribution of all pooled individuals and revealed a clumping distribution up to 9 m and random distribution at large scales. The spatial relationship between adults and juveniles did not reveal a positive association between them either at small or large scale. Stand structure also showed a variation for some structural parameters: tree-density and basal area in the Reserve. We suggest that seed dispersal mode by gravity should be the primary seed dispersal mode of A. africana. Chapter 7 assessed the potential effectiveness of PBR on preventing mistletoes proliferation on Shea tree individuals. Shea tree infestation by mistletoes was assessed in two contrasted habitats: land use areas (fields and fallows) and protected area (PBR). Results showed that about 80% of Shea trees are infested in land use area while only 27.3% of trees in PBR were infested. Overall, heavily infested Shea trees had significantly larger trunks and heights, mainly in land use areas. The land use area was shown to be correlated with high and very high Shea tree infestation degrees while the other infestation degrees (very weak, weak and moderate) were correlate with both areas. Therefore Shea trees growing in protected areas are better protected against mistletoe plant parasites than those on cultivated land. Chapter 8 deals with Variation of mistletoes impact on Shea tree fruit yield in contrasting habitats and implication for its conservation. Forty-one (41) weakly and 41 heavily infected Shea tree individuals with similar size were selected in protected area and in its adjacent parklands. Shea tree traits such as diameter at breast height, canopy diameter, tree height, canopy height, number of fruit yielded, number of parasite stumps and a built impact index ratio were assessed on each Shea tree individual. Two-way ANOVA showed that mistletoe did not impact fruit yield significantly either in parklands or in protected area. Hierarchical cluster analysis tended to group all pooled Shea trees based on habitats. One-way ANOVA and canonical discriminant analysis performed on quantitative traits revealed that Shea tree groups were significantly discriminated and many infested Shea tree individuals in parklands were characterized with highest value of number of infestation stumps (n) and impact index ratio. Considering correlation between traits, a variation was found between the two contrasted habitats. Findings have been used to implement some Shea tree conservation plans. Chapter 9 deals with the general discussion on effectiveness of the PBR to conserve biodiversity. The PBR was found to be relatively effective in targets biodiversity conservation. However, management actions need to be addressed to improve biodiversity conservation in this Biosphere Reserve.

  • Système agroforestier à Faidherbia albida. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Brousse tigrée (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Odo Octhèrè (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Building of the Laboratory of Applied Ecology (LEA). (Credit photo: Dr Akomian Fortuné Azihou / LEA, Abomey-Calavi, Benin, October 2018)
    Building of the Laboratory of Applied Ecology (LEA). (Credit photo: Dr Akomian Fortuné Azihou / LEA, Abomey-Calavi, Benin, October 2018)
  • Musée de Zoologie BIOTA et bâtiment Professeur Mama Adamou N'DIAYE. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Cascade de Tanongou (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Bâtiment Professeur Nestor SOKPON (en haut à gauche), bâtiment des volontaires (en bas à gauche), bâtiment Dr KASSA (à droite). (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Lokoli (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Vue globale des bâtiments du Laboratoire d’Ecologie Appliquée (LEA). (Photo credit: Dr Akomian Fortuné Azihou / LEA, Octobre 2018)
  • FM Deve (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Bâtiment Professeur Nestor SOKPON (à droite), bâtiment des volontaires de l'UAC (à gauche). (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Vue globale des 5 bâtiments du Laboratoire d’Ecologie Appliquée (LEA). (Photo credit: Dr Akomian Fortuné Azihou / LEA, Octobre 2018)
  • Mare-Bali (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Système Agroforestier à palmier à huile. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)


Feeding ecology and habitat use of bovid species in Pendjari Biosphere Reserve, Benin (West Africa)

PhD Dissertation: 

Chabi Adéyèmi Marc Sylvestre DJAGOUN (2013). Feeding ecology and habitat use of bovid species in Pendjari Biosphere Reserve, Benin (West Africa). Faculty of Agronomic Sciences, University of Abomey Calavi, Benin. 162 pages. 

Thesis director: Prof Brice SINSIN.

 

Abstract: This thesis endeavours to understand how grazing and browsing herbivores co-exist, with special emphasis on understanding the mechanisms of competition and facilitation over temporal and spatial scales. We focused on feeding ecology and habitat use study of the free ranging bovid species of Pendjari Biosphere Reserve in Northwestern Benin. Here we used stable light isotope analysis of faeces to identify, as well as quantify bovid food selection, diet niche segregation and habitat selection indices (Manly’s alpha) were calculated for each bovid species to assess if habitat use differed in each species across hunting and non-hunting zones. While presence/absence data were used in resource-selection functions based on Generalized Linear Mixed effect Model to examine how bovid species distribution were related to habitat structure and composition, landscape structure and human disturbance. Additionally, detailed data on the time-budget were collected through focal animal observation technique to determine whether the time budget activities of Bohor reedbuck, living in sympatric system was affected by vegetation cover and to test if herd size, position in herd, the age and sex affect vigilance efficiency.

 

Chapter 1 dealt with the background, starting research objectives, research questions and the thesis structure while chapter 2 dealt with the study area and study animal.

 

Chapter 3 analyzed bovid species habitat use and distribution with respect to habitat structure (micro and macro-habitat), landscape characteristics, and human disturbance factors in West Africa, a semi arid landscape, where bovid occupy the Biosphere Reserve characterized by different managed areas. We observed a clearly stronger avoidance towards opened habitats in the hunting zone than in the non hunting zone for the hartebeest, oribi, roan, kob, waterbuck and reedbuck, while the ecological and behavioural plasticity was most pronounced in the grey duiker, red-flanked duiker, bushbuck and buffalo which didn’t show any shift in habitat use across the managed areas. Besides habitat preferences attributed to each bovid species at landscape level, bovid species’ resource selection was influenced on a small scale by other factors such as habitat structure, landscape characteristics, and human disturbance factors suggesting that bovid species are influenced by a range of factors operating at different scales.

 

Chapter 4, analyzed the proportions of C3 browse:C4 grass in the diets of 11 bovid species in Pendjari Biosphere Reserve, Benin, West Africa. Of these, eight were expected to be grazers (buffalo, reedbuck, waterbuck, hartebeest, kob, oribi, roan and topi), and three browsers (red-flanked duiker, bushbuck and common duiker). Carbon isotope results from faeces of PBR bovids implied that only six species (buffalo, waterbuck, hartebeest, kob, roan and topi) had primarily C4 grass-dominated diets, whereas five species focused largely on C3 vegetation, i.e. browse (reedbuck, oribi, red-flanked duiker, bushbuck and common duiker). Given the discrepancies in % C4 in the diets of bovids from PBR compared with literature for other parts of Africa, it is clear that there is spatio-temporal dietary flux in many bovid species. Bovid diets are, to some extent, habitat-specific and averaging of % monocots in diet from continent-wide field studies does not adequately represent dietary diversity among African bovid species.

 

Chapter 5 studied an assemblage of eleven bovid species in Pendjari Biosphere Reserve and tested two nutritional hypotheses for the ecological diversity of ungulates, the browser/grazer (diet type) and diet quality models. Results show that, contrary to many predictions, body mass and diet type are not related, but these data confirm predictions that the diet quality decreases with increase in body size, both in dry and wet season. Our findings also show numerous patterns in resource partitioning amongst the 11 bovid species studied, suggesting that different species used different dietary resource in contrasting ways. We concluded that in our study area, due to abundant resources and low herbivore densities, especially in the wet season, niche breadth and diet overlap remain large, because there is no need for herbivores to specialize and to avoid competition over scarce resources.

 

Chapter 6, examined seasonal habitat features and diet partitioning in sympatric bovid species using waterbuck (Kobus ellipsiprymnus) and western kob (Kobus kob) as model species. In support of niche partition hypothesis, diets of western kob and waterbuck differed significantly along both faecal selection axis (δ13C and δ15N) during the resource scarcity period of dry season as opposed to wet season when there is resource abundance. Western kob and waterbuck resource partitioning does not occur only on the basis of diet segregation but also some habitat variables play an important role in the co-existing system with “distance to water” emerging as most important discriminatory variable.

 

Chapter 7, provided a valuable contribution to our knowledge on how coexistence in sympatric African mammal herbivores affect behaviour and vigilance of ungulate using Bohor reedbuck as model species. Our study adds to the large amount of evidence demonstrating the herd-size effect on ungulate vigilance, and it also adds the importance of sympatric grouping system in Bohor reedbuck behaviour and vigilance efficiency. In addition, habitat type and grass height did not affect the vigilance behaviour of the Bohor reedbuck. Our study has also shown that within-herd spatial position is an important factor to be taken into account in the study of vigilance behaviour. However, further study is needed to investigate the possible sex-specific functions and targets of vigilance behaviour and the effect of within-herd spatial position with respect to the herd direction in the field. The last chapter (Chapter 8) presented  a  general  discussion  and  conclusions  on  issues  tackled  in this thesis. Although each part of the study was approached independently, the various elements combined well providing an indication of the factors driving coexistence in bovid community of Pendjari Biosphere Reserve.

Key words: Bovid, diet, habitat use, coexistence, Pendjari, niche segregation, seasonality, Benin

 

  • Cascade de Tanongou (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Lokoli (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Vue globale des bâtiments du Laboratoire d’Ecologie Appliquée (LEA). (Photo credit: Dr Akomian Fortuné Azihou / LEA, Octobre 2018)
  • Odo Octhèrè (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Building of the Laboratory of Applied Ecology (LEA). (Credit photo: Dr Akomian Fortuné Azihou / LEA, Abomey-Calavi, Benin, October 2018)
    Building of the Laboratory of Applied Ecology (LEA). (Credit photo: Dr Akomian Fortuné Azihou / LEA, Abomey-Calavi, Benin, October 2018)
  • Système agroforestier à Faidherbia albida. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • FM Deve (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Mare-Bali (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Bâtiment Professeur Nestor SOKPON (à droite), bâtiment des volontaires de l'UAC (à gauche). (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Système Agroforestier à palmier à huile. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Vue globale des 5 bâtiments du Laboratoire d’Ecologie Appliquée (LEA). (Photo credit: Dr Akomian Fortuné Azihou / LEA, Octobre 2018)
  • Brousse tigrée (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Musée de Zoologie BIOTA et bâtiment Professeur Mama Adamou N'DIAYE. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Bâtiment Professeur Nestor SOKPON (en haut à gauche), bâtiment des volontaires (en bas à gauche), bâtiment Dr KASSA (à droite). (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)

Lions of West Africa Ecology of lion (Panthera leo Linnaeus 1758) populations and human-lion conflicts in Pendjari Biosphere Reserve, North Benin

PhD Dissertation: 

Etotépé A. SOGBOHOSSOU (2011). Lions of West Africa Ecology of lion (Panthera leo Linnaeus 1758) populations and human-lion conflicts in Pendjari Biosphere Reserve, North Benin. University of Leiden, The Netherlands. 158 p.

Promotors: Geert R. de SNOO & Brice SINSIN

Co-Promotor: Hans H. de IONGH.

 

Abstract: Earth’s biodiversity is disappearing at an alarming rate in the last decades. Many species, including carnivores, are becoming endangered. The lion was one of the most widely distributed terrestrial mammals and is today restricted to Gir ecosystem in India and to more or less fragmented populations in sub-saharan Africa. The species is considered as Vulnerable on IUCN Red List. In West Africa, due to its small and fragmented populations, the species is listed as Regionally Endangered. While the species is widely studied in other parts of Africa, it is poorly known in West Africa. The threats to lions, their ecology and their behaviour have not been assessed in the context of this region. In order to fill this gap, this research aims at investigating the ecology of the lion population and conflicts with humans in a West African protected area: Pendjari Biosphere Reserve, Benin. Pendjari Biosphere Reserve is one of the best-managed protected areas in West Africa and is part of the two most promising Lion Conservation Units in the region. It covers about 5,000 km² and is composed of the Pendjari National Park, and the Pendjari and Konkombri hunting zones.

Local populations surrounding the Pendjari Biosphere Reserve suffer from livestock depredation mainly by hyena (53.6% of attacks), baboon (24.8% of attacks) and lion (18% of attacks). Most attacks occur during the rainy season when wild prey are scattered and more difficult to hunt. The depredation level is relatively low compared to many other regions in Africa. However the losses are significant, as local populations live below the poverty line. Fortunately, despite these losses and the fear of carnivores, people tolerated conflicts. No retaliatory killing of predators was reported. This could be partly attributed to the social and cultural importance of carnivores. The low level of conflicts in Pendjari is confirmed by the absence of livestock in the diet of lions. In the relatively well protected Sudanian savannah area that Pendjari represents, buffalo is the most consumed species (50% of the prey biomass consumed). However, like in other areas of West and Central Africa, the lion diet is dominated by medium prey (61.7%) while large prey composed 38.2% of the diet. Similarly to what is observed across Africa, smaller prey such as oribi and duiker were avoided and relatively large prey such as waterbuck and hartebeest were preferred. The predominance of small prey in the diet is then due to the relative abundance of these prey and not to the small size of lion groups in the region. There are about 1.6 lions/100 km² in the Pendjari Biosphere Reserve. The mean lion group size is of 2.6 lions with a significantly higher group size in the park compared to that in hunting zones. The adult sex ratio of 1 male : 1.04 female is skewed towards males. The small group size could be linked to the low prey and lion densities in the area. The lion population is particularly vulnerable to trophy hunting both in hunting zones of Pendjari and hunting zones of Burkina Faso, as the park’s lion population plays the role of source population while the hunting zone lions represent the sink populations. The mean home range of lionesses (95% MCP: 200 ± 141 km²) is consistent with findings across Africa. Riparian forests, woodlands and dry forests were the preferred lion habitats during the dry season while grasslands and swamps were used according to their availability. The few available results showed that during the rainy season, when most of the reserve is flooded, lions preferred woodlands on hills and avoid grasslands and swamps. The study of the home range and the social structure of lions in Pendjari highlighted the need for a concerted management of Benin and Burkina Faso lion populations for better efficiency. In summary, when protected areas are safe enough, lion population ecology and behaviour are similar across Africa. The Pendjari lion population was increasing and did not represent a great threat to livestock and humans surrounding the reserve. The lion population remained vulnerable, however, mainly because of legal and illegal hunting and human encroachment from neighbouring reserves. The impact of hunting and human activities on the social structure need to be better investigated. To save the lion in the region of West Africa, efforts should be made to safeguard only protected areas but also their surrounding areas. Studies on other issues such as the impact of lion trophy hunting and the relationship between the different large predators will contribute to improve the status of lions and other predators in West Africa.

Keywords lion Panthera leo; human-wildlife conflicts; social structure; feeding ecology; habitat use; West Africa

 

  • Bâtiment Professeur Nestor SOKPON (en haut à gauche), bâtiment des volontaires (en bas à gauche), bâtiment Dr KASSA (à droite). (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Lokoli (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Système agroforestier à Faidherbia albida. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Brousse tigrée (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • FM Deve (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Bâtiment Professeur Nestor SOKPON (à droite), bâtiment des volontaires de l'UAC (à gauche). (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Cascade de Tanongou (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Vue globale des 5 bâtiments du Laboratoire d’Ecologie Appliquée (LEA). (Photo credit: Dr Akomian Fortuné Azihou / LEA, Octobre 2018)
  • Odo Octhèrè (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Système Agroforestier à palmier à huile. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Vue globale des bâtiments du Laboratoire d’Ecologie Appliquée (LEA). (Photo credit: Dr Akomian Fortuné Azihou / LEA, Octobre 2018)
  • Mare-Bali (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Musée de Zoologie BIOTA et bâtiment Professeur Mama Adamou N'DIAYE. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Building of the Laboratory of Applied Ecology (LEA). (Credit photo: Dr Akomian Fortuné Azihou / LEA, Abomey-Calavi, Benin, October 2018)
    Building of the Laboratory of Applied Ecology (LEA). (Credit photo: Dr Akomian Fortuné Azihou / LEA, Abomey-Calavi, Benin, October 2018)

Tropical Grasses Silicification: Genetic Interspecific Variation, Influence of Growth Conditions and Relationship with the Foliar Structure

PhD Dissertation: 

Valentin Kindomihou (2005). Tropical Grasses Silicification: Genetic Interspecific Variation, Influence of Growth Conditions and Relationship with the Foliar Structure. Laboratory of Plant Ecology and Biogeochemistry, Botanical Garden Jean Massart, Interfaculty School of Bioengineers, Free University of Brussels, Belgium. 193 pages.

Promotors: Prof Pierre Meerts (ULB, Belgique) & Prof Brice Sinsin (UAC, Benin).

 

SUMMARY: This thesis investigates the variation in tropical grasses silicification on the ecological and evolutionary point of view. The review of works examining variation extent in silica concentration identifies three groups of factors influencing the grass silicification, in particular genetic factors (difference in the capacity of root absorption, anatomy and foliar ecophysiological features), endogenous factors (phenology, organs) and the growth conditions. The experimental approach focused the influence of certain growth conditions on the silica concentration (defoliation, moisture, substrate fertility). Results confirm the influence of defoliation and substrate fertility on the silica accumulation, but well underline the complexity of the action of these factors which results in particular in different responses of species. These results suggest that contradictions in published works with regard to the plausible inducible character of silica accumulation are due in some extent to the species*defoliation interaction, and a great results sensitivity to conditions for defoliation application.  Variations in silica content (intrinsic and induced by the growth conditions) relating to the variations in structural and functional characters (specific leaf area, water content, foliar anatomy, etc.) showed correlations which are not entirely constant through all the tests. These are significantly positive with soluble ashes in all tests, but negative with carbon in defoliation. With the relative water content, silica correlated positively in defoliation, but change with phospho- nitrogenized fertilization. This negative correlation remains consistent in both blades and sheaths in interspecific comparison. Difference in the structure of correlations results at the same time from the sampling effects and the large range of the silica contents swept by the various examined species. Pennisetum unisetum is the richest in silica and sclerenchyma, and weights disproportionately in correlations analysis. Our results do not provide a very clear support for the assumption that silica can be substitute to carbon compounds like material of support.

 Key words: grass, tropical, silicification, anatomy, structure, defoliation, fertilization, moisture.

  • Mare-Bali (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Building of the Laboratory of Applied Ecology (LEA). (Credit photo: Dr Akomian Fortuné Azihou / LEA, Abomey-Calavi, Benin, October 2018)
    Building of the Laboratory of Applied Ecology (LEA). (Credit photo: Dr Akomian Fortuné Azihou / LEA, Abomey-Calavi, Benin, October 2018)
  • Lokoli (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Bâtiment Professeur Nestor SOKPON (à droite), bâtiment des volontaires de l'UAC (à gauche). (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Brousse tigrée (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Musée de Zoologie BIOTA et bâtiment Professeur Mama Adamou N'DIAYE. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Système Agroforestier à palmier à huile. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Système agroforestier à Faidherbia albida. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Bâtiment Professeur Nestor SOKPON (en haut à gauche), bâtiment des volontaires (en bas à gauche), bâtiment Dr KASSA (à droite). (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • FM Deve (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Cascade de Tanongou (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Odo Octhèrè (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Vue globale des 5 bâtiments du Laboratoire d’Ecologie Appliquée (LEA). (Photo credit: Dr Akomian Fortuné Azihou / LEA, Octobre 2018)
  • Vue globale des bâtiments du Laboratoire d’Ecologie Appliquée (LEA). (Photo credit: Dr Akomian Fortuné Azihou / LEA, Octobre 2018)


Diversity, leaf biomass of fodder trees and carrying capacity of rangelands in the Guineo-Congolese / Sudanian transition zone of Benin

PhD Dissertation: 

Clément SEWADE (2017). Diversity, leaf biomass of fodder trees and carrying capacity of rangelands in the Guineo-Congolese / Sudanian transition zone of Benin. Doctoral School of Water and Agronomic Sciences, University of Abomey Calavi, Benin. 242 pages.

Thesis promotor: Prof. Dr Ir. Marcel Romuald Benjamin HOUINATO.

SUMMARY: Native plant species in general and fodder trees in particular contribute significantly to the daily needs of both human and animal especially in developing countries. During the dry season, fodder trees are an important source for the survival of ruminants because of herbaceous forage lack. They are multipurpose species exploited by various actors who are sometimes protagonists. In view of the pressure faced by these trees, and their consequent rarity noted in rangelands, a study was conducted in the Guineo-Congolese/Sudanian transition zone of Benin at the level of the local population surrounding the protected forests of Monts Kouffé, Wari-Maro and Ouémé Supérieur. This thesis contributes to the rational management of fodder trees’ resources. Specifically, it aims at (i) evaluate the diversity, the pastoral and conservation priority of fodder trees; (ii) assess the influence of age, sex and ethnicity on the perception of fodder species use values; (iii) describe the relationship between the availability and the use status of fodder species; (iv) develop models for estimating leaf biomass of three priority browse species; (v) contribute to the understanding of the socio-cultural dynamics of the study area in relation to the fodder trees’ exploitation and the associated conflicts. A total of 220 informants belonging to three sociolinguistic groups (Bariba, Nago and Peul) were interviewed through a semi-structured survey on the fodder trees that they use for different purposes. The citation rates of the fodder trees by the surveyed populations were used to establish pastoral priority, while their conservation priority was established using a combination of four methods and nine criteria. The use categories were defined in the study area and at an international level for the use rates calculation. The ethnoecological approaches were used to analyze the availability of fodder tree species in the study region. A total of 25 trees per species were sampled for biomass estimating. Carrying capacity was determined for the dry season in the study area. A total of 48 fodder trees belonging to 17 families dominated by Leguminosae (27.1%) and Moraceae (16.6%) were reported. These species were distributed among 37 genera, with the genus Ficus being the most represented (16.6%). Palatability, species availability and the impact of tree fodder on animal productivity were the criteria used by the surveyed sociolinguistic groups in their selection of fodder trees. The prioritization methods yielded ten top ranked species: Afzelia africana, Pterocarpus erinaceus, Khaya senegalensis, Vitellaria paradoxa, Mangifera indica, Ficus platyphylla, Balanites aegyptiaca, Annona senegalensis, Ficus umbellata and Daniellia oliveri. As a multipurpose species, the fodder trees are classified in six use categories: food, medicine, construction, fuel, veterinary and fodder. A. africana, K. senegalensis and P. erinaceus are the most widely used species by Peul and Bariba sociolingustic groups to feed animals, while the Nagos use M. indica comes first followed by F. umbellata, F. platyphylla and P. Erinaceus. Combining the different use categories, overharvested or underutilized species depend significantly on the sociolinguistic group. The forest inventory revealed 63 tree species of dbh ≥ 10 cm distributed in 24 families and 52 genera. The most represented families in genus and species are Leguminosae (28.57 %), Combretaceae (14.28 %). The Leguminosae family had the highest importance values (FIVI=83.42) followed at a distance by Combretaceae (21.68). The most important and ecologically dominant species are V paradoxa (SIVI = 42.76); I. doka (41,88); B. ferruginea (22.98); and D. oliveri (16,18). It is also noted that aerial fodder production significantly varied among species. The best models that estimated leaf biomass production of A. africana and P. erinaceus were obtained with diameter at breast height; a plant trait not directly affected by pruning as predictors. For D. oliveri the best model uses the crown height as estimator parameter. Globally, the carrying capacity of each species is about 0.05 to 0.09 TLU ha-1an-1 for A. africana; 0.03 to 0.08 TLU ha-1an-1 for P. erinaceus and 0.04 to 0.79 TLU ha-1an-1 for D. oliveri. The number of animal that can sustainably be fed in the study area was 38 497 TLU. Conflicts arise between sawyers and foresters, between foresters and Peul (herders), farmers and herders, farmers and sawyers, foresters and farmers. These conflicts are caused by the illegal exploitation of trees for their timber and fodder, and the breeders camp near the agricultural areas or sometimes in the forest reserves. Direct negotiations between those involved in conflicts or the arbitration of a local authority were the main strategies and ways of these conflicts managing. With the aim of establishing a sustainable management of pasture lands, we suggest that priority be given to the pastoral and conservation priority species witch are also overexploited species in the restoration, afforestation/reforestation and plantation activities. The introduction of these fodder tree species in afforestation/reforestation activities can improve the availability of leaf biomass to feed animals.

Keywords: Availability, Benin, Biodiversity, Conservation priority, Ethnoecology, Fodder trees, Leaf biomass, Pastoralism.

  • Système agroforestier à Faidherbia albida. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • FM Deve (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Brousse tigrée (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Bâtiment Professeur Nestor SOKPON (en haut à gauche), bâtiment des volontaires (en bas à gauche), bâtiment Dr KASSA (à droite). (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Building of the Laboratory of Applied Ecology (LEA). (Credit photo: Dr Akomian Fortuné Azihou / LEA, Abomey-Calavi, Benin, October 2018)
    Building of the Laboratory of Applied Ecology (LEA). (Credit photo: Dr Akomian Fortuné Azihou / LEA, Abomey-Calavi, Benin, October 2018)
  • Cascade de Tanongou (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Bâtiment Professeur Nestor SOKPON (à droite), bâtiment des volontaires de l'UAC (à gauche). (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Système Agroforestier à palmier à huile. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Mare-Bali (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Vue globale des bâtiments du Laboratoire d’Ecologie Appliquée (LEA). (Photo credit: Dr Akomian Fortuné Azihou / LEA, Octobre 2018)
  • Lokoli (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Odo Octhèrè (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)
  • Vue globale des 5 bâtiments du Laboratoire d’Ecologie Appliquée (LEA). (Photo credit: Dr Akomian Fortuné Azihou / LEA, Octobre 2018)
  • Musée de Zoologie BIOTA et bâtiment Professeur Mama Adamou N'DIAYE. (Photo credit: Dr Akomian Fortuné Azihou / Laboratoire d’Ecologie Appliquée (LEA), Octobre 2018)