Yao Agbelessessi Woegan

Disturbance and Population StructureofPlant Communities in theWildlife Reserveof Oti-Mandouri in Togo (West Africa)

Aims: As a contribution to the sustainable management of protected areas in Togo, this study aims to analyze the impact of anthropogenic activities on plant communities in the wildlife reserve of Oti -Mandouri (North-Togo). Study Design:The study area is located in the Sudanian zone, in northeast Togo. Place and Duration of Study:The field work was carried out during April and June 2009, whilst processing data was done at Lab From July to October 2009. Methodology: Total height and stem diameter at breast height (dbh) greater than 10 cm of all trees species were measured in 126 plots. In each plot, ecological parameters were recorded and the seedling and suckers (dbh<10cm) of species were counted. Results:116 woody species with dbh greater than 10 cm belonging to 33 families and 84 Original ResearchArticle

Long term evaluation of green vegetation cover dynamic in the Atacora Mountain chain (Togo) and its relation to carbon sequestration in West Africa

The research was done in the Atacora Mountain chain in Togo which tended to assess the change of vegetation cover during a 24-year period. It also aims to evaluate the dynamic of the net primary productivity (NPP) of the living plants over the same period. The Landsat imagery covering three different periods (1987, 2000, and 2011) was pre-processed to correct atmospheric and radiometric parameters as well as gapfilling the 2011 SCL-off images. Then, the vegetation indices such as NDVI (normalized difference vegetation index), SR (simple ratio vegetation index), SAVI (soil-adjusted vegetation index), and CASA (carnegie- ames- stanford approach)model for NPP were applied on these images after masking the study area. The results showed a quiet decrease in the vegetation cover. The vegetation loss was more significant from 2000 to 2011 than from 1987 to 2000, and anthropogenic activities can be deemed as the main cause of the vegetation loss. The biomass assessment by NPP computation also showed a decrease over the time. Similar to the change of the vegetation cover, the ecosystem net productivity was very low in 2011 compared to 2000 and 1987. It seems that the general health condition of the vegetation, including its potentiality in carbon sinking, was negatively affected in this area, which has already been under threatened. A perpetual monitoring of these ecosystems by means of efficient techniques could enhance the sustainable management tools of in the framework of reducing emissions from deforestation and forest degradation (REDD).

Distribution spatiale des plantes alimentaires mineures ou menacées de disparition au Togo: un indicateur de l’ampleur de leur menace

Résumé L’analyse de la problématique des plantes alimentaires mineures et menacées au Togo a pris en compte l’aspect distribution spatiale afin de mieux juger de l’ampleur de la menace. L’étude a été menée sur la base des enquêtes ethnobotaniques dans 280 localités distribuées sur toute l’étendue du territoire togolais. Au total, 137 espèces alimentaires mineures et menacées de disparition au Togo ont été inventoriées. Le nombre de plantes alimentaires en disparition varie de 2 à 40 suivant les localités et de 10 à 50 chez la plupart des ethnies. L’amplitude de leur distribution spatiale montre 20% des plantes signalées en régression sur l’étendue du territoire national. En revanche, 10%, 18% et 18% des plantes ont des distributions respectivement septentrionale, centrale et méridionale. Le reste des plantes présente des distributions interrégionales. Ces différentes distributions traduisent des degrés de menace qui dépendent non seulement du nombre de citations de la plante, mais aussi de l’aire de distribution naturelle de l’espèce.

Diversité des formations végétales ligneuses du Parc national de Fazao- Malfakassa et de la réserve d'Aledjo (Togo)

des sciences sous la direction du professeur Akpagana Koffi, a été soutenue le 10 avril 2007 à l’Université de Lomé (Togo) en vue de l’obtention du grade de docteur de l’Université de Lomé, option Biologie du développement, spécialité Biologie végétale. Le jury ayant évalué ce travail était composé de : professeur Messanvi Gbeassor (Université de Lomé, Togo), professeur Brice Sinsin (Université d’Abomey-Calavi, Bénin), professeur Thiou Komlan T. Tchamiè (Université de Lomé, Togo) et professeur Koffi Akpagana (Université de Lomé, Togo).