Analyse phytosociologique de la végétation de la réserve naturelle forestière de Vyanda au Sud-Ouest du Burundi

La réserve naturelle forestière de Vyanda subit des pressions anthropiques permanentes et risque de disparaître avant qu’elle ne soit étudiée. La présente étude a pour objectif de déterminer la composition et la diversité de la végétation de cette réserve et de motiver la prise des mesures de conservation localement adaptées. L’étude a procédé par l’inventaire de la végétation suivant la méthode du relevé phytosociologique de Braun Blanquet (1932). Des spectres bruts et pondérés des formes biologiques, des types de diaspores et des types phytogéographiques ont été établis. Les résultats de l’inventaire floristique ont fait état de 108 espèces réparties en 81 genres et 41 familles. Sur le plan des formes biologiques et des types de diaspores, les phanérophytes et les sarcochores dominent tandis que les hémicryptophytes de même que les sclérochores sont bien représentés. Sur le plan phytogéographique, l’étude a mis en évidence une forte représentativité de l’élément paléo-africain, de l’élément soudano-zambézien et de l’élément guinéo-congolais. Ces spectres attestent la spécificité de cette réserve comme forêt claire du type miombo tout en mettant en évidence l’impact des perturbations dont elle est victime. L’étude met en évidence la richesse spécifique de la réserve et démontre l’intérêt qu’il y a de prendre des mesures visant à arrêter les perturbations anthropiques et à bien gérer ce milieu naturel. Sa diversité est en effet grande comparé aux autres réserves naturelles du voisinage. English title: Phytosociological analysis of the vegetation of the Vyanda natural forest reserve in southwestern Burundi The Vyanda natural forest reserve is under constant human pressure and is in danger of disappearing before it is studied. The objective of this study is to determine the composition and diversity of the vegetation of this reserve and to motivate the taking of locally adapted conservation measures. The study carried out a vegetation inventory using the Braun Blanquet (1932) phytosociological approach. Spectra of life forms, phytogeographical elements and diaspores morphology were established. The results of the floristic inventory revealed 108 species divided into 81 genera and 41 families. In terms of life forms and types of diaspores, phanerophytes and sarcochores dominate when hemicryptophytes as well as sclerochores are well represented. Phytogeographically, the study revealed a strong representativeness of the Paleo-African element, the Sudano-Zambezian element and the Guinean-Congolese element. These spectra attest to the specificity of Vyanda natural forest reserve as an open forest of the miombo type while highlighting the impact of the disturbances that affect it. The study highlights the specific richness of the reserve and its diversity and demonstrates an urgent need to take measures to stop anthropogenic disturbances and well managing this natural ecosystem. Its diversity is indeed great compared to other natural reserves in the region.

Floristic Inventory and Evaluation of Carbon Sequestration Potential of the Misomuni Forest Massif, Kikwit City (Democratic Republic of the Congo)

The aim of this study was to inventory plant biodiversity and to evaluate the carbon sequestration potential of the Misomuni forest massif. An inventory of all trees with diameter at breast height (dbh) ≥ 10 cm measured at 1.30 m height was performed. The aerial biomass (AGB) was used for estimating the stored CO2 and its carbon equivalent. 88 plant species belonging to 71 genera and 32 families were inventoried. Fabaceae family displayed the highest number of species and genera. The highest basal area values were displayed by Scorodophloeus zenkeri (7.34 ± 2.45 m2 /ha), Brachystegia laurentii (5.82 ± 1.94 m2 /ha), Entandrophragma utile (5.28 ± 1.94 m2 /ha), Pentadesma butyracea (4.53 ± 1.51 m2 /ha). The highest values of stored carbon and their carbon equivalent were observed in Pentadesma butyracea (15.13 ± 5.00 and 50.55 ± 16.85 t/ha), Picralima nitida (7.02 ± 2.34 and 23.66 ± 7.88 t/ha), Strombosia tetandra (6.56 ± 2.18 and 22.10 ± 7.36 t/ha). The Misomuni forest massif is thus much floristically diversified and plays a significant role in the sequestration of CO2. The total AGB of the inventoried trees is 183.78 ± 61.26 t/ha corresponding to stored carbon and carbon equivalent of 96.63 ± 32.21 t/ha and 289.92 ± 96.64 t/ha respectively. The protection of this ecosystem is highly needed for combatting climatic changes at local, national and regional scales and for the conservation biodiversity habitat.

FLORISTIC DIVERSITY OF THE GROUPING AT PISTACIA ATLANTICA IN THE REGION OF NAÂMA (ALGERIA)

Floristic inventory carried out on grouping range at Pistacia atlantica in southern region of Naama makes it possible to identify 135 taxa, divided into 36 families and 105 genera. This large specific diversity, belong to 36 botanical families, best represented (48%) being Asteraceae, Poaceae, Fabaceae and Brassicaceae. The biological analysis shows predominance of Therophytes with 68 species, i.e. 50%. This predominance is characteristic of arid regions vegetation which adapt to saharan and steppe environment. The biogeographic analysis reveals a predominance of three biogeographical types (mediterranean, saharan and endemic) with a rate of 64% or 87 species. This biogeographic distribution reveals floristic heterogeneity and confirms mediterranean affinity of region flora, which combines three sets: high steppe plains, saharan atlas and Saharan border to South.

A floristic inventory and reassessment of the Flora of Sanibel Island (Lee Co.), Florida, U.S.A.

Sanibel Island (Lee Co., Florida) manifests eight main categories and 12 subcategories of habitats, and individual plant taxa occupy habitat(s) from one or more of those categories. Documented, presently as growing wild/apparently wild on Sanibel Island are individuals of 119 families, 397 genera, 611 species (including two hybrids), and 621 infrageneric taxa of vascular plants. Of the 621 infrageneric taxa, 420 (67.6%) are native and 13 (2.1 %) are endemic to Florida. We interpret the Island’s flora in terms of its history of severe natural and artificial disturbances.

Preliminary Floristic Inventory of the Swamp Forest of Atan Ukwok Village in Ini L.G.A of Akwa Ibom State, Nigeria

The Floristic inventory of the swamp forest at Atan Ukwok was carried out using the Systematic and Transect Sampling Methods where the line transect was the main path of the forest and Sampling units were chosen along the path at a distance of 14m × 14m and 6 sampling plots were sampled. The frequency, density and abundance of the identified species were calculated using standard formulae. A total number of 61 species from 35 families were identified. The number of species recorded for the plant families were, Cyperaceae 5, Euphorbiaceae 4, Acanthaceae, Apocynaceae, Asteraceae, Aspidiaceae and Poaceae 3 each, Arecaceae, Caesalpiniaceae, Mimosaceae, Melastomataceae, Schizaceae, Thelypteridaceae and Verbanaceae 2 each and Athyriaceae, Costaceae, Dioscoreaceae, Dracaenaceae Gleicheniaceae Araceae, Davillianaceae, Malvaceae, Commelinaceae, Clusiaceae, Selaginellaceae, Combretaceae, Convolvulaceae, Colchicaceae, Fabaceae, Moraceae, Malvaceae, Lycopodiaceae and Rutaceae 1 each. The highest species frequency and density of 66.7% and 9.5% respectively was found in Setaria megaphylla and the highest abundance value of 50.0 was found in Dracaena arborea. The frequency percentage of the plant species showed that the forest is fast loosing vegetation due to the obvious encroachment of parts of it by the inhabitants of the community for the purpose of cultivation. This calls for concerted conservation measures in order to ensure the sustainable use of the floral diversity of the forest.

Evaluación de pastizales consumidos por alpacas madres y tuis (Vicugna Pacos) en bofedales en época seca, Yauyos, Perú

The research was carried out in the alpaca production unit of the Tomas Peasant Community, of the Lima Region, with the aim of identifying the floristic component of the pasture of a wetland area in the dry season of the year and the species that were most consumed by alpacas. Previously, the floristic inventory of 5 hectares of pasture was carried out and 10 mother alpacas and 10 tuis alpacas were assigned. During the study period, stool samples were taken to evaluate the diet by the microhistological method. The chemical components of the six main species of grasses most consumed were analyzed. In the initial inventory 36 species were found, of which the most consumed were 10 that made up approximately 80% of the diet. Chemical analysis shows a crude fiber content in a range between 66,23 to 77,24%, crude protein between 2.49 to 5,21% and vitamin A between 0,08 to 0,37 mg / 100g. The contribution of the present is to identify the species of pasture most consumed by alpacas tuis and mothers, in order to take care in their conservation.

Regeneration indicators of Detarium microcarpum Guill. & Perl. in the Mbe plain of the Adamawa, Cameroon

Background In Africa, the Detarium microcarpum Guill. & Perr. species is extremely important culturally, ecologically and socio-economically. This importance has led to its over-exploitation leading to an in situ rarity of its individuals. As a consequence, a conservation alert is increasingly reported across the continent due to the risk of extinction of this multipurpose plant. Unfortunately, indicators of regeneration and conservation guidelines for this species have been not developped yet. The objective was to evaluate the habitat, population distribution, dendrometric characteristics and structure of the plant which are indicators of regeneration in Cameroon. Methodology A floristic inventory as well as the vegetation transect method was used in the villages Def, Karna Manga and Karna Petel located in Adamawa, Cameroon. Results A total of 109 individuals of the plant were counted with a density of 3.5 individuals per hectare. No plant individuals regenerated in human-controlled habitats (bush fields and home gardens). Population distribution, companion species (Bombax costatum, Piliostigma thonningii and Terminalia macroptera) more recurrent, species of the family Caesalpiniaceae in majority, dendrometric characteristics with a significant difference (P ˂ 0.05) between sites, horizontal and vertical structures although all significant at Karna Manga, showed site-specific patterns. Conclusion The regeneration indicators (habitat, population distribution, structure and dendrometric characteristics: crown diameter, diameter at breast height, height of the first large living branch and tree height) showed that conservation in situ requires accounting for local, site-specific conditions. For the continuation, the less expensive domestication techniques specific to the plant are recommended.