Woody plant communities of Comoe-Leraba reserve: Characterisation and impact of soils on their distribution

The protected areas are worth great in vegetation conservation; this supported their interest in scientific research on the tools being able to be used for their sustainable management. The present study enters within the framework of a better knowledge of Comoé-Léraba reserve plants communities’ and the soils conditions which explained their distribution, in the aim to make better decisions for it conservation. The objective of the survey is to discriminate the plants communities in relation to soils’ physicals and chemicals parameters which control their distribution. Thus, 368 physociological plots have been done in the field by applying Braun-Blanquet (1932) method and then the plants communities’ package has been carried out in CANOCO software. In related to each ecosystem, 11 plants communities’ have been clearly defined, according the phytosociological statements (DCA). Among these communities four news syntaxons were determined based on previous studies in the same phytogeographical zones. Then their direct ordination (CCA) with soil’s (physical and chemical) parameters, shows that plants communities’ distribution is governed mainly by the water regulation on the ground and also its texture. The obtained results will certainly contribute to lay down a constant policy maker in biodiversity conservation. Lieux de refuge et de conservation de la végétation, les aires protégées sont des zones potentiellement diversifiées. Elles suscitent un grand intérêt pour la recherche en vue de découvrir des outils pouvant servir à leur gestion durable. La présente étude entre dans le cadre d’une meilleure connaissance des communautés végétales de la réserve de la Comoé-Léraba et des conditions édaphiques qui sous-tendent leur installation en vue de faciliter les prises de décisions entrant dans le cadre de sa conservation. Ainsi, l’objectif était de discriminer les groupements végétaux en relation avec les paramètres édaphiques qui gouvernent leur distribution. Sur le terrain, 368 relevés physociologiques ont été réalisés en appliquant la méthode de Braun Blanquet (1932) et l’individualisation des groupements végétaux a été réalisée grâce au logiciel CANOCO. L’analyse a permis de discriminer 11 groupements végétaux dont la classification syntaxonomique révèle quatre nouveaux taxons comparativement aux études réalisées dans les zones phytogéographiques similaires. L’ordination directe (CCA) intégrant les paramètres physiques et chimiques des sols, permet de considérer la texture et les paramètres hydriques des sols comme étant les plus efficients dans la distribution des groupements végétaux. Les résultats obtenus contribueront certainement à définir une politique soutenue de la conservation de la biodiversité

The urban park Bangr-Wéoogo : an area of the conservation of the floristic diversity in the city of Ouagadougou, Burkina Faso

Les résultats de 227 relevés phytosociologiques selon l’approche phytosociologique effectuées au Parc Urbain Bangr-Wéoogo de Braun-Blanquet (1932) montrent que malgré son contexte de forte pression anthropique avec plus d´un million d’habitants aux alentours, cette forêt urbaine conserve encore de nos jours une diversité floristique appréciable avec 327 espèces inventoriées comprenant 117 espèces ligneuses et 210 espèces herbacées. Cette flore qui est répartie dans 11 groupements individualisés grâce aux espèces différentielles, est constituée essentiellement de phanérophytes et de thérophytes. La répartition phytogéographique des espèces montre leur appartenance à plusieurs empires phytogéographiques dominés par les espèces Soudano-Zambeziennes et Pantropicales. La richesse floristique du parc qui contraste avec son environnement, est le résultat d’une politique d’aménagement et de conservation efficace de la biodiversité initiée par l'État et ses partenaires depuis 1936. Mots clés: Flore, conservation, aménagement, spectre biologique, Parc Urbain, Ouagadougou, Burkina Faso, groupements végétauxThe results of 227 relevés taken in the urban park of Bangr-weoogo by applying the phytosociological approach of Braun-Blanquet (1932) show that the park, consisting mainly of forest formations, still has an important species richness in spite of the high human pressure caused by more than 1 million habitants in the surroundings. The total number of species is 327 comprising 117 woody species and 210 herbaceous species. The flora forms 11 plant communities and is mostly constituted by phanerophytes and therophytes. The phytogeographical distribution of species shows that Soudano-Zambesian and pantropical species are dominating. Key words: Flora, conservation, management, biological spectrum, urban park, Ouagadougou, Burkina Faso, plant communitie

Floristic diversity of classified forest and partial faunal reserve of Comoé-Léraba, southwest Burkina Faso

: The classified forest and partial faunal reserve of Comoé-Léraba belongs to the South Sudanian phytogeographical sector of Burkina Faso and is located in the most humid area of the country. This study aims to present a detailed list of the Comoé-Léraba reserve’s flora for a better knowledge and conservation. Floristic inventories have permitted to record 540 plant species belonging to 342 genera and 91 families, thus representing 26.12% of Burkina Faso’s phytodiversity (2067 species). Fabaceae and Poaceae with 89 and 51 species respectively, were the dominant families. The vegetation is characterized by the dominance of both phanerophytes (45.51%) and therophytes (32.73%). The importance of Guineo–­Con­golian species proves that the Comoé-Léraba flora belongs to the Sudano–Guinean transition sector. Comoé-Léraba also accounts the highest number of exclusive species followed by the reserve of Sahel in the country. Exclusive species bring out its value in flora conservation

Le Parc Urbain Bangr-Wéoogo: une aire de conservation de la diversité floristique au coeur de la ville de Ouagadougou, Burkina Faso

The results of 227 relevés taken in the urban park of Bangr-weoogo by applying the phytosociological approach of Braun-Blanquet (1932) show that the park, consisting mainly of forest formations, still has an important species richness in spite of the high human pressure caused by more than 1 million habitants in the surroundings. The total number of species is 327 comprising 117 woody species and 210 herbaceous species. The flora forms 11 plant communities and is mostly constituted by phanerophytes and therophytes. The phytogeographical distribution of species shows that Soudano- Zambesian and pantropical species are dominating.Les résultats de 227 relevés phytosociologiques selon l’approche phytosociologique effectuées au Parc Urbain Bangr-Wéoogo de Braun-Blanquet (1932) montrent que malgré son contexte de forte pression anthropique avec plus d’un million d’habitants aux alentours, cette forêt urbaine conserve encore de nos jours une diversité floristique appréciable avec 327 espèces inventoriées comprenant 117 espèces ligneuses et 210 espèces herbacées. Cette flore qui est répartie dans 11 groupements individualisés grâce aux espèces différentielles, est constituée essentiellement de phanérophytes et de thérophytes. La répartition phytogéographique des espèces montre leur appartenance à plusieurs empires phytogéographiques dominés par les espèces Soudano-Zambeziennes et Pantropicales. La richesse floristique du parc qui contraste avec son environnement, est le résultat d’une politique d’aménagement et de conservation efficace de la biodiversité initiée par l’Etat et ses partenaires depuis 1936

Spatial and Temporal Dynamics of the Vegetation of Comoé-Léraba Reserve and its Surrounding Lands (Burkina Faso, West Africa)

In Burkina Faso, vegetation dynamic has been more influenced by human activities. Actually, the interest is focus on protected areas, which are more green areas and the last habitat for biodiversity. Conservation and restoration require a thorough understanding of the dynamic of each protected area and its surrounding zones. This study aim to analyze Comoé-léraba protected area vegetation spatial and temporal changed. For this study, we use satellite images taking account a period of twenty years (1990-2000-2009). Then the diachronic analysis considers globally and separately the land cover situation inside the protected zone and outside in the surrounding zone. As results, the diachronic study of Comoé-Léraba vegetation revealed significant changes. Some plant communities have remained intact; others were restored inside the protected area and against others suffered a severe deterioration. The vegetation degradation occurs, around and close to the protected area. During the twenty years 14.28 % of the natural vegetation has been loss, versus expanding fields and settlements. Beyond the obtained maps, an important data based is available. These results are important scientific stools which can support policy, conservationists and researchers for improving strategies of conservation in Comoé-Léraba zone

Spatially explicit multi-threat assessment of food tree species in Burkina Faso : a fine-scale approach

Over the last decades agroforestry parklands in Burkina Faso have come under increasing demographic as well as climatic pressures, which are threatening indigenous tree species that contribute substantially to income generation and nutrition in rural households. Analyzing the threats as well as the species vulnerability to them is fundamental for priority setting in conservation planning. Guided by literature and local experts we selected 16 important food tree species (Acacia macrostachya, Acacia senegal, Adansonia digitata, Annona senegalensis, Balanites aegyptiaca, Bombax costatum, Boscia senegalensis, Detarium microcarpum, Lannea microcarpa, Parkia biglobosa, Sclerocarya birrea, Strychnos spinosa, Tamarindus indica, Vitellaria paradoxa, Ximenia americana, Ziziphus mauritiana) and six key threats to them (overexploitation, overgrazing, fire, cotton production, mining and climate change). We developed a species-specific and spatially explicit approach combining freely accessible datasets, species distribution models (SDMs), climate models and expert survey results to predict, at fine scale, where these threats are likely to have the greatest impact. We find that all species face serious threats throughout much of their distribution in Burkina Faso and that climate change is predicted to be the most prevalent threat in the long term, whereas overexploitation and cotton production are the most important short-term threats. Tree populations growing in areas designated as ‘highly threatened’ due to climate change should be used as seed sources for ex situ conservation and planting in areas where future climate is predicting suitable habitats. Assisted regeneration is suggested for populations in areas where suitable habitat under future climate conditions coincides with high threat levels due to short-term threats. In the case of Vitellaria paradoxa, we suggest collecting seed along the northern margins of its distribution and considering assisted regeneration in the central part where the current threat level is high due to overexploitation. In the same way, population-specific recommendations can be derived from the individual and combined threat maps of the other 15 food tree species. The approach can be easily transferred to other countries and can be used to analyze general and species specific threats at finer and more local as well as at broader (continental) scales in order to plan more selective and efficient conservation actions in time. The concept can be applied anywhere as long as appropriate spatial data are available as well as knowledgeable experts

Climate change threat magnitude levels ‘Very high’ and ‘High’ combined for all species.

<p>The criteria to define the threat levels are presented in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0184457#pone.0184457.t005" target="_blank">Table 5</a>.</p

<i>Boscia senegalensis</i>.

<p><b>Threat magnitude levels of (A) ‘Overexploitation’, (B) ‘Overgrazing’, (C) ‘Fire’, (D) ‘Climate change’, (E) ‘Cotton production’, (F) ‘Mining’ and (G) ‘Combined threat’.</b> The criteria to define the threat levels are presented in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0184457#pone.0184457.t005" target="_blank">Table 5</a>.</p

Species richness map of 16 important food tree species and eco-climatic zones.

<p>The three eco-climatic zones (Sahelian zone: < 600mm/a, Sudano-Sahelian zone: 600–900 mm/a and Sudanian zone: > 900 mm/a) are defined by the annual rainfall [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0184457#pone.0184457.ref004" target="_blank">4</a>] and are represented in this map by the bioclimatic variable 12 from the WorldClim 1.4 dataset [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0184457#pone.0184457.ref041" target="_blank">41</a>].</p