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Les parcs agroforestiers occupent des superficies non negligeables au Burkina Faso. Mais, du fait de la pression fonciere, ils subissent des formes d’exploitation qui menacent leur existence dans le moyen terme. Pour une gestion durable des parcs agroforestiers, leur connaissance sur le plan floristique s’impose. C’est ainsi qu’une etude floristique a ete menee dans les parcs agroforestiers des forets classees de Dinderesso et de Kuinima a l’Ouest du Burkina Faso. L’objectif est de contribuer a une meilleure gestion du peuplement ligneux des parcs agroforestiers. Pour ce faire, un inventaire forestier dans des placettes circulaires de 900 m² a ete realise en vue d’etablir la liste floristique, la diversite specifique et d’apprecier l’etat de la regeneration et l’etat sanitaire des peuplements ligneux. Au total, 27 especes ligneuses reparties en 14 familles et 27 genres dans les parcs agroforestiers de Dinderesso et 27 especes ligneuses reparties en 12 familles et 26 genres dans les parcs agroforestiers de Kuinima ont ete inventoriees. La diversite specifique de Shannon-Weaver est faible avec 1,80 bit pour les parcs agroforestiers de Dinderesso et 1,33 bit pour ceux de Kuinima. La regeneration est beaucoup plus marquee par l’espece Vitellaria paradoxa Gaertn.f. suivie de Anacardium occidentaleL. [cult.]. Les taux de regeneration sont de l’ordre de 54,12% et 9,41% pour Dinderesso puis 35,64% et 26,60% pour Kuinima respectivement, pour Vitellaria paradoxa et Anacardium occidentale. L’appreciation de l’etat sanitaire revele que 49,85% des pieds de Vitellaria paradoxa inventories dans la foret classee de Kuinima sont parasites. Par contre dans la foret classee de Dinderesso, le taux de parasitisme des pieds de Vitellaria paradoxa est de 13,37%. Au regard de ces taux de parasitisme, il est plus que necessaire de developper des strategies de lutte contre ces plantes parasites. A court et moyen termes si rien n’est fait, ces parasites affecteront considerablement les capacites de cette espece agroforestiere a fournir des biens et services. Agroforestry parks occupy significant areas in Burkina Faso. But, due to land pressure, they are subjected to forms of exploitation which threaten their existence in the medium term. For a sustainable management of agroforestry parks, their flora knowledge is essential. Thus, a floristic study was carried out in the agroforestry parks of the classified forests of Dinderesso and Kuinima in western Burkina Faso. The objective is to contribute to better management of the woody settlement in agroforestry parks. So, a forest inventory in circular plots of 900 m² was carried out in order to establish the floristic list, the specific diversity and to assess the state of regeneration and the state of health of the woody settlement. A total of 27 woody species divided into 14 families and 27 genera in the agroforestry parks of Dinderesso and 27 woody species divided into 12 families and 26 genera in the agroforestry parks of Kuinima were inventoried. The specific diversity of Shannon-Weaver is low with 1.80 bit for the agroforestry parks of Dinderesso and 1.33 bit for those of Kuinima. Regeneration is much more marked by the species Vitellaria paradoxa Gaertn. f. followed by Anacardium occidentale L. [cult.]. The regeneration rates are of the order of 54.12% and 9.41% for Dinderesso, then 35.64% and 26.60% for Kuinima, respectively for Vitellaria paradoxa and Anacardium occidentale. The assessment of the health status reveals that 49.85% of Vitellaria paradoxa plants inventoried in the Kuinima classified forest are parasitized. On the other hand in the classified forest of Dinderesso, the rate of parasitism of the feet of Vitellaria paradoxa is 13.37%. In view of these parasitism rates, it is more than necessary to develop strategies to combat these parasitic plants. In the short to medium term, if left unchecked, these pests will significantly affect the ability of this agroforestry species to provide goods and services.

The main objective of this study was to evaluate two restoration techniques, “stone rows” and “stone rows + tree planting” on soil organic carbon (SOC) sequestration and structure in terms of water stable aggregates as well as the time required to restore soil fertility. The Carbon, Aggregate and Structure Turnover (CAST) model was used to model the changes of SOC content and water stable aggregate formation under the two restoration techniques. Field experiments used for calibration of the model were conducted using a randomized block design. Soil samples were class fractionated followed by a micro-aggregate isolation procedure. The two restoration techniques contributed significantly to improving soil total carbon content. By running five year simulation of the “stone rows”, the estimated total carbon input was 27 Mg ha-1 of which 6.1 Mg ha-1 were sequestered in the soil and 20.7 Mg ha-1 were released as CO2. In “stone rows + planting”, the total SOC content after five years was estimated to be 22.96 Mg ha-1, which was broken down to 15.43 Mg ha-1 aggregated carbon and 26.60 Mg ha-1 CO2. Fifty-year simulations showed a SOC increase to 54.8 Mg ha-1 in “stone rows”, and to 86.0 Mg ha-1 in “stone rows + planting”. This means that natural grassland vegetation slowly improves soil carbon content and soil quality, but with trees behind stone rows, the result will be about 50% higher.

Kuinima forest ecosystem, a classified forest, located in western Burkina Faso, is undergoing accelerated degradation due to climatic hazards and anthropogenic factors such as excessive cutting of trees, bush fires, etc. The main objective of this study is to assess the contribution of three water and soil conservation techniques (Zai forest, stone rows, Zai forest+ stone rows) to soil carbon sequestration and their impact on some soil physicochemical parameters. Thus, soil samples were taken, and the physicochemical parameters of the soil were analyzed in the laboratory. The organic carbon stock was calculated based on the results of the carbon content analysis. The results revealed that the treatments had higher clay and silt contents than the control. The treatments also had a significant impact on soil organic carbon content, total nitrogen, available potassium and cation exchange capacity over the 0-20 cm depth. Compared to the control, the Zai forest, Zai forest+stone rows and stone rows treatments led to respective increase in the carbon stock of 166%, 77% and 21%. In conclusion, this study has shown that Zai forest and stone rows can contribute significantly to soil carbon sequestration to fight against climate change.

According to the Brundtland report, sustainable development considers the environment as part of development. Taking into account the environment for sustainable development has compelled us to explore other activities that are yet to be explored. Suggested activities to reach sustainable development include ecotourism. In order to better conserve its protected areas, Burkina Faso has undertaken the development of its natural reserves in the ecotourism sector. This paper focuses on promoting ecotourism in the Niangoloko Natural Reserve in southwest Burkina Faso. Thus, from the map of Niangoloko natural reserve plant communities, inventory plots of the ecotourism potential of each plant community were installed to measure the resources in the fields of shade, landscape diversity, and food resources. The results showed that, among the eleven plant communities of the natural reserve, some of them captivate visitors by their shade, their panorama or the abundance of fruit resources. Three plant communities can serve as shade place, four plant communities are very abundant in fruit resources, and the facies of vegetation with a striking panorama are very widespread. Niangoloko natural reserve, unexplored so far, can be valued in ecotourism because of its huge natural assets and its easy accessibility. Depuis la publication du rapport Brundtland, le concept de developpement durable tient compte de la reconnaissance de l'environnement comme element de developpement. La nouveaute de la prise en compte de l'environnement dans le developpement durable, nous oblige a explorer d'autres domaines d'activites jusque-la inexplores. Parmi la multitude d’activites proposees pour l’evolution des societes contemporaines vers un developpement durable figure l'ecotourisme. Le Burkina Faso a entrepris la valorisation de ses reserves naturelles dans le secteur de l’ecotourisme afin de mieux conserver ces espaces proteges. A cet egard l’objectif de la presente etude est donc de promouvoir l’ecotourisme dans la reserve naturelle de Niangoloko au sud-ouest du Burkina Faso. Ainsi, a partir de la carte des groupements vegetaux de la reserve naturelle, des releves d’inventaires des potentialites ecotouristiques de chaque groupement ont ete installes pour mesurer les ressources dans les domaines de l’ombrage, de la diversite des paysages et des ressources alimentaires. Les resultats montrent que, sur les onze groupements vegetaux de la reserve naturelle, certains fascinent le visiteur par leur ombrage, leurs facies au panorama saisissant, la beaute feerique de leurs paysages ou par l’abondance des ressources fruitieres. Trois groupements vegetaux peuvent servir de lieu de detente pour l’ombrage, quatre groupements sont tres abondantes en ressources fruitieres et les facies de vegetation au panorama saisissant sont tres repandus. En conclusion, cette reserve jusqu’alors inexploree dans le domaine de l’ecotourisme peut se preter a des projets ecotouristiques en vue de ses immenses atouts naturels et son accessibilite facile.

L’objectif de cette etude etait de determiner l’influence des activites anthropiques incontrolees ainsi que du type de vegetation sur la structure des peuplements de Isoberlinia spp.. Les donnees ont ete collectees dans 43 placeaux installes dans les forets claires et les savanes arborees/boisees situees dans la foret classee et hors foret classee. Les parametres consideres ont ete le diametre, la hauteur, la densite, la surface terriere et la valeur d’importance ecologique. Le test non-parametrique de Kruskal-Wallis et la distribution de Weibull ont permis respectivement de comparer les moyennes et d’apprecier la dynamique. Dans la foret classee, les valeurs moyennes du diametre, de la hauteur et de la surface terriere etaient plus elevees et differaient (p 0,05) entre les deux entites. La densite de regeneration est importante, mais peu s’affranchissent. Suivant le type de formation vegetale, les forets claires sont dominees par des individus de gros diametres et de grande taille. La structure de Isoberlinia spp . presente une allure en cloche avec le parametre de weibull c = 2,32, traduisant une distribution asymetrique positive avec une predominance d’individus de gros diametre. Les peuplements de Isoberlinia spp . sont mieux conserves dans la foret classee, notamment dans les forets claires. Cependant, la faible capacite de l’espece a assurer la succession des classes menace la survie de ces peuplements. La prise de mesures de gestion appropriees alors s’impose. © 2019 International Formulae Group. All rights reserved Mots cles: Degradation, peuplements, structure, foret classee de Koulbi, forets claires English Title: Effects of anthropogenic pressure on stands of Isoberlinia doka Craib and Stapf and Isoberlinia tomentosa (Harms) Craib and Stapf in the Sudanian zone of Burkina Faso English Abstract The objective of this study was to determine the influence of uncontrolled human activities and vegetation type on the stand structure of Isoberlinia spp . Data were collected in 43 plots installed in woodland, tree and wood savannah stands located inside the protected and unprotected areas. Parameters considered were stem diameter, tree height, stand density, basal area and importance value index. The non-parametric Kruskal-Wallis test was used to compare averages. The Weibull distribution was used to assess the structure dynamic of stands inside and outside the protected area. In the protected area, the mean values of diameter, height and basal area were significantly higher (p 0.05) between the groups. The density of the regeneration is quite important. But most of them (75%) remain in the height class] 0 to 0.5 m]. According to vegetation types, woodland are dominated by large individuals. The structure of Isoberlinia spp . has a bell shaped curve with the weibull parameter c = 2.32, reflecting a positive asymmetric distribution with a predominance of large diameter individuals. The stands of Isoberlinia spp . are better conserved in the classified forest, especially in open forests. The low regeneration capacity threatens the survival of these stands in the long term. So better management measures are therefore needed to halt the degradation process. © 2019 International Formulae Group. All rights reserved Keywords: Degradation stands structure, classified forest of Koulbi, woodland

Objectif : L’etude ethnobotanique a ete menee a l’echelle de la region de Tahoua avec pour objectif la capitalisation des connaissances endogenes des tradipraticiens sur les differentes utilisations des especes vegetales vendues dans les marches. Methodologie : Des enquetes ethnobotaniques a l’aide d’interviews individuelles sur la vente des plantes medicinales ont ete realisees de juin 2017 a avril 2018 aupres de 44 vendeurs et vendeuses installes dans 44 marches ruraux hebdomadaires du centre ouest du Niger (Region de Tahoua). Resultats : L’etude a permis de recenser au total, 49 especes reparties en 40 genres et 28 familles. Sur les 49 especes recensees dans les marches, 28 peuvent etre rencontrees dans la zone d’etude soit 57,14%. Aussi, 15 especes sur ces 28 sont les plus vendues et 18 de plus en plus rares selon les tradipraticiens enquetes. Aussi, les resultats de l'etude ont montre que l’ecorce chez les ligneux et la plante entiere chez les herbacees sont les plus utilisees. Pour la plupart, les remedes sont prepares sous forme de decoction. Conclusion et applicabilite des resultats : Le recours quasi exclusif des populations locales aux especes vegetales medicinales dans leurs soins quotidiens accentue la pression sur les ressources medicinales pouvant conduire a la disparition de certaines especes. Il est donc necessaire et urgent d’envisager la substitution de certaines plantes medicinales par la medecine moderne en vue de sauver les plus vulnerables. Mots cles : Capitalisation, plantes medicinales, decoction, etude ethnobotanique, Tahoua, Niger Ethnobotanical study of medicinal plants sold in the markets of central western Niger Objective : This ethnobotanical study was conducted at the Tahoua region with the aim of capitalizing endogenous knowledge of traditional healers on the different uses of plant species sold in markets. Methodology : Ethnobotanical surveys using individual interviews on the sale of medicinal plants were conducted from June 2017 to April 2018 among 44 vendors and vendors in 44 weekly rural markets in west-central Niger (Tahoua Region). Results : The study identified a total of 49 species in 40 genera and 28 families. Of the 49 species identified in the markets, 28 can be found in the study area or 57.14%. Also, 15 of these 28 species are the most sold and 18 are increasingly rare according to the traditional healers surveyed. Also, the results of the study showed that the bark in the woody and the whole plant in the herbaceous are the most used. For the most part, the remedies are prepared as a decoction. Conclusion and application of results : The almost exclusive use of local populations to medicinal plant species in their daily care increases the pressure on medicinal resources that can lead to the disappearance of certain species. It is therefore necessary and urgent to consider the substitution of certain parts of the plant and the planting of exploited species. Keywords: Capitalization, medicinal plants, decoction, ethnobotanical study, Tahoua, Niger

Cette etude constitue un travail preliminaire a la mise en place de techniques d’amenagement, de conservation des eaux et des sols, de defense et de restauration des sols en zone soudanienne (pluviometrie moyenne annuelle de 1 000 mm). Les ressources ligneuses du bassin-versant du Kou subissent une degradation acceleree. Pour la contrer, une caracterisation pedologique fine du sol, la description des etats de surfaces par la methode dite line-intercept et un inventaire exhaustif de la vegetation ont ete realises. Les resultats revelent l’existence de quatre types de sols. L’etude des surfaces elementaires a montre que seulement 40,7 % des superficies du site pourraient etre favorables a l’infiltration. La vegetation ligneuse se compose pour l’essentiel de Caesalpiniaceae, de Combretaceae, de Rubiaceae, d’ Annonaceae et de Mimosaceae. La tendance evolutive de la vegetation ligneuse s’est revelee positive dans toutes les parcelles, ce qui laisse presager des possibilites de restauration assez rapides.

Les forets claires resultent de la degradation des forets denses seches. Elles sont soumises aux facteurs climatiques et anthropiques. Cette etude vise a analyser la diversite floristique et la dynamique des principales especes dans la foret classee de Koulbi. Les donnees ont ete collectees dans 27 placeaux de 900 m 2 . Le diametre (Dbh 1,30 m) >5 cm et la hauteur des individus ont ete mesures. La regeneration a ete comptee et l’etat sanitaire apprecie. Les indices de Shannon et de Pielou, la valeur d’importance ecologique de l’espece (IVI), la densite et la surface terriere ont ete calcules. La distribution de Weibull a ete appliquee a la structure des principales especes. L’indice de Shanonn = 3,01 bits montre une diversite moyenne et l’indice de Pielou = 0,49 traduit la dominance de quelques especes. Les especes ayant un IVI significatif sont Anogeissus leiocarpa (DC.) Guill. Et Perr. (116,19), Pterocarpus erinaceus Poir. (21,66), Lannea barteri Oliv. Engl. (13,40), Adansonia digitata L. (12,92) et Vitellaria paradoxa Gaertn. (11,80). La principale espece, A. leiocarpa presente une bonne densite tant au niveau des adultes (316 pieds/ha) que des juveniles (667 pieds/ha). Sa structure diametrique en «J renverse» est synonyme d’une bonne dynamique. Cependant, elle est menacee par la mortalite (9,27%) par endroit des sujets. Mots cles : Diversite floristique, regeneration, mortalite, foret classee de Koulbi.

Desertification and land degradation affect the livelihood of a large number of people in the drier areas of the world, but there is no generally accepted scale, on which the degree of degradation can be measured. However, scientists are working on finding indicators of degradation, although it can be difficult to identify to what these indicators might be related.In this paper, we have investigated a number of soil-physicochemical parameters in relation to a degradation scale of land uses. The results show that high sand content and C/N values may be used as indicators of degradation, and high contents/values of carbon, organic matter, nitrogen, available K+, CEC, SBE may be used as indicators of no or weak degradation. CEC showed the steepest gradient in relation to land use and may be the most useful soil physicochemical degradation indicator.The investigated land uses had different densities of trees, which was the reason for suggesting the vegetative biomass relative to a virgin forest situation as a scale of degradation. Desertification and land degradation affect the livelihood of a large number of people in the drier areas of the world, but there is no generally accepted scale, on which the degree of degradation can be measured. However, scientists are working on finding indicators of degradation, although it can be difficult to identify to what these indicators might be related.In this paper, we have investigated a number of soil-physicochemical parameters in relation to a degradation scale of land uses. The results show that high sand content and C/N values may be used as indicators of degradation, and high contents/values of carbon, organic matter, nitrogen, available K+, CEC, SBE may be used as indicators of no or weak degradation. CEC showed the steepest gradient in relation to land use and may be the most useful soil physicochemical degradation indicator.The investigated land uses had different densities of trees, which was the reason for suggesting the vegetative biomass relative to a virgin forest situation as a scale of degradation.