- Tokyo To, Meguro-Ku, Komaba 4-5-29
- +818078050737 / +22966547852
Akotchiffor Kévin Géoffroy DJOTAN
University of Abomey-Calavi, Forestry, Graduate Student
- The University of Tokyo, Forestry, Department Memberadd
- MSc. Forestry & Natural Resources Management, Research Student at UTokyo, Laboratory of Forest Botany (Tree and Forest Health) Research Collaborator at the Laboratory of Forest ... moreMSc. Forestry & Natural Resources Management, Research Student at UTokyo, Laboratory of Forest Botany (Tree and Forest Health) Research Collaborator at the Laboratory of Forest Sciences (Forest Management) Expertise: Biodiversity Informatics, GIS & Spatial Analysis, Biostatistics and Data Management. Instigator of Green Methods Green Country Cabinetedit
The harvest of the seeds of Acacia auriculiformis becomes very difficult when the tree gets older. This study has assessed the viability, and the germination performance of the species’ seeds eventually conserved in the soil. For this... more
The harvest of the seeds of Acacia auriculiformis becomes very difficult when the tree gets older. This study has assessed the viability, and the germination performance of the species’ seeds eventually conserved in the soil. For this purpose, an experiment was carried out over a period of seven weeks to count the number of seedlings emerging from the composite soil samples collected in an old plantation of Acacia auriculiformis in South Benin. Samples were randomly collected over a horizontally stratified scale (provenance), but systematically collected over a vertically stratified scale (depth). The samples have been set to minimum conditions of germination. Germination method was used to assess the viability and the germination performance of seeds. The independence of those parameters with regard to considered factors was tested with Khi-2. Finally, GLM models were used to explain the recorded trends. Depth and provenance seem both to significantly European Scientific Journal February 2019 edition Vol.15, No.6 ISSN: 1857 – 7881 (Print) e - ISSN 1857- 7431 272 influence assessed parameters. Soil from the plantation can hold up to 267 viable seeds of Acacia auriculiformis per m² especially inside the plantation in the first layer of the ground. It is possible to rely on those soil’s seeds to alleviate the difficulties related to seedling supply in Benin.
Research Interests:
The harvest of the seeds of Acacia auriculiformis becomes very difficult when the tree gets older. This study has assessed the viability, and the germination performance of the species’ seeds eventually conserved in the soil. For this... more
The harvest of the seeds of Acacia auriculiformis becomes very difficult when the tree gets older. This study has assessed the viability, and the germination performance of the species’ seeds eventually conserved in the soil. For this purpose, an experiment was carried out over a period of seven weeks to count the number of seedlings emerging from the composite soil samples collected in an old plantation of Acacia auriculiformis in South Benin. Samples were randomly collected over a horizontally stratified scale (provenance), but systematically collected over a vertically stratified scale (depth). The samples have been set to minimum conditions of germination. Germination method was used to assess the viability and the germination performance of seeds. The independence of those parameters with regard to considered factors was tested with Khi-2. Finally, GLM models were used to explain the recorded trends. Depth and provenance seem both to significantly influence assessed parameters. Soil from the plantation can hold up to 267 viable seeds of Acacia auriculiformis per m² especially inside the plantation in the first layer of the ground. It is possible to rely on those soil’s seeds to alleviate the difficulties related to seedling supply in Benin.
Research Interests:
Fighting against invasive species is a great challenge that requires knowledge about their potential distribution areas. Ageratum conyzoides is an invasive species in several African countries including Benin. In order to analyze the... more
Fighting against invasive species is a great challenge that requires knowledge about their potential distribution areas. Ageratum conyzoides is an invasive species in several African countries including Benin. In order to analyze the vulnerability of protected areas of Benin to the invasion of this species, and to guide managers of these areas to fight against invasions, this study used MaxEnt to model the ecological niche of the species under the current and future climates, horizon 2055 RCP 4.5 and RCP 8.5 scenarios. Environmental data and presence data were gathered respectively from the data bases of AfriClim and GBIF. From the current to the future climates, the potentially suitable areas for the distribution of the species shift from the center to the south of Benin. So, about 75%, 51% and 65% of Benin's total area are respectively suitable under present climate, and future's ones (RCP4.5 and RCP8.5). Only about 16% and 43% of this area are absolutely unsuitable and absolutely suitable to the species. As for protected areas, about 29% and 25% of their total area are respectively not vulnerable, and vulnerable to Ageratum conyzoides. Present climate, and future's ones
Research Interests:
ACKNOWLEDGMENTS This work is a contribution to the achievement of data use in the framework of the Biodiversity Information for Development (BID) projects funded by the European Union and facilitated by the Global Biodiversity Information... more
ACKNOWLEDGMENTS This work is a contribution to the achievement of data use in the framework of the Biodiversity Information for Development (BID) projects funded by the European Union and facilitated by the Global Biodiversity Information Facility (GBIF). ABSTRACT Khaya senegalensis Desr & Juss is an urban tree species with high quality wood, unfortunately disturbed by Hypsipyla robusta Moore. However, how vulnerable this species is with regard to climate change and to Hypsipyla robusta over time and space is unknown. This study aimed at assessing as well the climate change impacts on both species as the overlapping extent of their suitable areas over time and space. To this end, the MaxEnt approach for Ecological Niche Modelling was used to compute suitable areas for both species under current and future climates (Africlim RCP 4.5 and RCP 8.5). Spatio-temporal Analysis was performed using Geographic Information System. Upon 2055, climate change will impact negatively 15-16% of Benin while the positive impacts will account only for 2-3%, and the stable areas will represent 74-75%. As for Hypsipyla robusta, climate change will provide only habitat loss of about 66% of the country. So, many plantation sites are exposed to biological attack from the pest, but wouldn " t be more in future, giving hope for Khaya senegalensis' high quality wood production. Meanwhile, there will be an ecological imbalance due to the drastic potential habitat loss for the insect.
Research Interests:
study was conducted to assess how well climate changes can help to conserve and restore Garcinia kola Heckel in the Protected Area Network (PAN) and in urban areas in Benin. To achieve this, occurrence data from GBIF was used and the... more
study was conducted to assess how well climate changes can help to conserve and restore Garcinia kola Heckel in the Protected Area Network (PAN) and in urban areas in Benin. To achieve this, occurrence data from GBIF was used and the environmental data from AfriClim was used in order to model the species’ potential habitat under current and future climates. The maximum entropy modeling approach of MaxEnt was used with scenarios RCP4.5 and RCP8.5 for future predictions. Geographic information systems were used to establish the high confidence prediction areas (HCPA) for G. kola. Gap analysis was performed throughout PAN and municipalities with regard to the HCPA. Considering the climate envelope, results revealed that climate change proved to have only positive consequences on the distribution of the species. Moreover, considering the HCPA, the percentage of municipalities that were suitable for the species is far above the percentage of PAN that was predicted as suitable (7.44% versus 0.93%). RCP4.5 and RCP8.5 indicated respectively 3.00 and 6.27% of PAN as positive climate change impact zones. As for the municipalities, it was respectively 13.60 and 17.60% of the total municipalities areas. Therefore, it is not worth relying only on PAN to conserve and restore the species, rather urban forestry and reforestation in PAN may be key actions to save this genetic resource. Further studies with regard to introduction of G. kola in urban areas and its use for reforestation are
compulsory.
compulsory.
Research Interests:
Dialium guineense is a multipurpose species useful in many respects. It is used in agroforestry and the trade of most of its organs is source of income for rural populations. Despite the high interests of this species to populations, we... more
Dialium guineense is a multipurpose species useful in many respects. It is used in agroforestry and the trade of most of its organs is source of income for rural populations. Despite the high interests of this species to populations, we do not know much about how its spatial distribution could be impacted by climate change and which strategies to implement for its sustainable use and conservation. In order to overcome these challenges, MaxEnt was used to model the ecological niche of D. guineense and different decision thresholds w ere used to interpret and classify the outputs. Climate will impact the distribution of D. guineense. Indeed under Africlim rcp 4.5 horizon 2055, the predicted stable areas of species distribution will be about 73% of West Africa when the threshold of the minimum training presence is considered and will decrease to 12% when the threshold of the maximum training sensitivity plus specificity is considered. Under Africlim 8.5 horizon 2055, the corresponding values for the stable areas of the species are, respectively 70 and 8% of the study area. In comparison with the global results of West Africa, in Benin, D. guineense will be less threatened by climate change. As strategies for sustainable use and conservation of the species, growing and introducing it in its favorable areas to account for its absence or low densities, is recommended. Also, building capacities to the users of the species so that they can grow it on their farms is recommended.
Research Interests:
This study aimed to diagnose the functioning of Atchérigbé forest sector. This sector cover an area of 2947,40 ha and is located between 7°30' and 7°34' Northern latitude and 2°04' and 2°09' Eastern longitude. The general objective of the... more
This study aimed to diagnose the functioning of Atchérigbé forest sector. This sector cover an area of 2947,40 ha and is located between 7°30' and 7°34' Northern latitude and 2°04' and 2°09' Eastern longitude. The general objective of the study is to improve theoretical knowledge by practicing while contributing to the sustainable management of Teak plantations of Benin. To achieve this goal, we participated to the activities in progress in the sector, consulted documents of which the principal were memories and thesis. Semi-structured and structured
interviews and participating observations were the main tools used to get information on the activities, the Strengths, Weaknesses, Opportunities and Threats of the sector, as well as the problems involved in the management of this sector. The tool "hones and stones" was used to hierarchy the problems. Also, we inventoried young plantations (of three years) of Tectona grandis in order to study their structural characteristics. Our results showed that the principal activity of the sector is the afforestation and related tasks. The principal force of the sector is the elaboration of a Planning document.However, the shallow soils with rocky outcrop are great weakness. This made unproductive
enough areas of the plantation as shown by the results of the inventory. The priority problem identified was "the intentional burning of the plantation" by local population. The main causes of this problem are the dispossessing, by ONAB, of the bordering population from their land.
Communication, sensitization, and repression are the best solutions to solve this problem.
Key words: Diagnostic Study, inventory, plantation of Tectona grandis, Atchérigbé, Benin
interviews and participating observations were the main tools used to get information on the activities, the Strengths, Weaknesses, Opportunities and Threats of the sector, as well as the problems involved in the management of this sector. The tool "hones and stones" was used to hierarchy the problems. Also, we inventoried young plantations (of three years) of Tectona grandis in order to study their structural characteristics. Our results showed that the principal activity of the sector is the afforestation and related tasks. The principal force of the sector is the elaboration of a Planning document.However, the shallow soils with rocky outcrop are great weakness. This made unproductive
enough areas of the plantation as shown by the results of the inventory. The priority problem identified was "the intentional burning of the plantation" by local population. The main causes of this problem are the dispossessing, by ONAB, of the bordering population from their land.
Communication, sensitization, and repression are the best solutions to solve this problem.
Key words: Diagnostic Study, inventory, plantation of Tectona grandis, Atchérigbé, Benin