Flora, Structure and Carbon Sequestration of Vegetation in the Southeast of the Mono Biosphere Reserve in Togo Amidst Environmental Challenges

In most Sub-Saharan African countries such as Togo, people’s heavy dependence on ecosystem services is a major factor in accelerating the degradation of natural resources, which are already suffering as a result of climatic factors. This study was initiated to contribute to the sustainable and rational management of forest resources in the south-east of the Mono Biosphere Reserve in Togo. It specifically aims to identify and characterize the flora of the residual forest ecosystems within the reserve through their specific diversity, demographic structure, and carbon sequestration potential. The study was carried out in the forest ecosystems of Avévé. The methodology used was based on the analysis of phytosociological, forestry, ecological, and regeneration inventory data. Overall, the study revealed that the RBMT still has floristically viable habitats, despite the anthropogenic pressures it is subject to revealed a floristic diversity of 160 plant species divided into 52 families and 135 genera. The most represented families are Rubiaceae (29.09%), followed by Fabaceae (27.94%). The most represented species are Mitragyna inermis (Willd.) Kuntze (24.38%), Lecaniodiscus cupanioides Planch. Ex Benth (X) and Lonchocarpus sericeus (Poir.) Kunth (10.93%). The high presence of Mitragyna inermis observed in all the ecological groups identified makes it the characteristic species of the flooded marshy areas of southeast Togo and contributes to the resilience of the ecosystems and populations in the study area. The Shannon index for the formation groups varies between (3.03 and 5.16) bits. Pielou’s equitability varies between (0.43 and 0.63) bits. The overall average density is estimated at 210 stems/ha, with an average diameter of 25.57 ± 21.77 m and an average height of 7.93 ± 3.83 m. The adjustment of the diameter classes of the plant groups to the Weibull distribution gave an “inverted J” shape with coefficient values of less than 1 overall, reflecting the existence of multispecific or uneven-aged stands. Assessment of the horizontal and vertical structure shows a predominance of the shrub layer in all the groups identified. The carbon sequestration potential is 41.89 T/Ha. Despite ongoing anthropogenic pressures, the Mono Biosphere Reserve abounds in a relatively rich diversity of flora, the preservation of which is essential for the survival of biodiversity and even for the riparian population. The data provided by this study would form the basis for sustainable management planning of the forest islands in the biosphere reserve.

In vitro antiplasmodial activity of crude extracts from Togolese medicinal plants

Objective:To investigate the antimalarial effect of a few plants in Togo folk medicine. Methods:After ethnobotanical survey,Opilia celtidifolia,Pavetta corymbosa（P.corymbosa） and Tamarindus indica（T.indica） were selected for screening.In vitro antimalarial tests were performed on crude extracts against fresh clinical isolates of Plasmodium falciparum using the semi microtest.Results:Different IC50,values of the extracts ranged from 2.042 to 100.000μg/mL. According to the results,the methanol extract of aerial part of P.corymbosa followed by aqueous extract of fruit of T.indica were the most active(IC50 of 2.042 and 4.786μg/mL,respectively). Qualitative test revealed the presence of alkaloids in the leaves of P.corymbosa that may be responsible for the activity of the plant.Conclusions:Our study provides scientific evidence for usage of plant in the folk medicine,and further studies are needed for identification and purification of the active principles.

Spatio-Temporal Distribution of Southeastern Community Forests in Togo (West Africa)

The present study aimed to provide the basics needed to reconcile the fight against poverty with the need of a good management of community resources in the context of local and sustainable development. It focused on the identification of geographic location and spatio-temporal dynamics of these resources in the southeastern part of Togo. The methodological approach was based on the spatial analysis of the area for the years 1988, 2000 and 2018 by combining optical imagery from Landsat TM, ETM+ and Sentinel-2A MSI satellites with radar imagery from Sentinel-1A IW/GRDH. Spatial analysis showed a fragmented spatial structure undergoing major changes for the period 1988-2018. Plantations, riparian formations, agglomerations, water bodies and wetlands increased respectively by 4.61%, 2.09%, 1.07%, 0.43% and 0.35% annually, while forests, savannahs, crops and fallow lands decreased annually by 0.71%, 5.87% and 1.97%. For the “forests” class, seven community forests geographically organized in three sub-groups were identified and mapped. The analysis of their areas pointed to the fact that out of 667 ha of community forests in 1988, only 415 ha remain in 2018, which means a loss of 37.78% in forest areas over the 30 years, or an annual deforestation rate of 1.64%. The different spatial changes observed could be attributed to several unsustainable human activities. The land use maps for the years 1988, 2000 and 2018 will contribute to resource localization and protection in sensitive areas or, in other words, to the integrated and rational management of these resources. The different identified and mapped community forests could serve as management units for managers in developing their management plans.

Coastline Change Modelling Induced by Climate Change Using Geospatial Techniques in Togo (West Africa)

Climate change is a major concern of humanity. One of the consequences of climate change is global warming causing melting glaciers, rising sea levels and shoreline regression. In Togo, the regression of shoreline leads to coastal erosion with significant damage on socio-economic infrastructures and human habitats. This research, basing on geospatial techniques, focuses on coastal erosion monitoring from 1988 to 2018 in Togo. It is interested in the extraction of shoreline and in the analysis of change. Various satellite images indexes have been developed for shoreline extraction but the major scientific problem concerns the precision of the different classification algorithms methods used for the extraction of the shoreline from these water index. This study used NDWI index from multisource satellite images. It assesses the performance of Otsu threshold segmentation, Iso Cluster Unsupervised Classification and Support Vector Machine (SVM) Supervised Classification methods for the extraction of the shoreline on NDWI index. The topographic morphology such as linear and non-linear coastal surfaces have been considered. The estimation of the rates of change of the shoreline was performed using the statistical linear regression method (LRR). The results revealed that the SVM Supervised Classification method showed good performance on linear and non-linear coastal surface than the other methods. For the kinematics of the shoreline, the southwest of the Togolese coast has an average erosion rate ranging from 2.49 to 5.07 m per year. The results obtained will serve as decision-making support tools for the design and implementation of appropriate adaptations plans to avoid the immersion of the asphalt road by sea, displacement of population and disturbance of human habitats.

Natural Distribution of <i>Nauclea diderrichii</i>(Rubiceae) in Semi Deciduous Forest of Togo (West Africa) and Implementation of Integrated Silviculture

West African tropical forests spread from Senegal to Togo. They are considered as one of the world biodiversity hotspots. But these forests are disappearing very quickly because of human activities. In Togo, tropical forests degradation has been increased since 1980 because of improved coffee cultivation;about 67% of forests in the sub-humid mountains zone disappeared between 1978 and 2000. Facing this fast deterioration of the forests, populations begin to plant teak (an exotic species) that is the only choice proposed by local forest service. This survey consists in valuing the potentialities to restore the Togolese tropical forest using the local commercial species, recognized on the wood market. The first species retained is Nauclea diderrichii (De Wild. & Th. Dur.) Merrill, that spreads in the African tropical forest from the Sierra Leonne to Uganda and through the Congo basin. In Togo, this plant species colonises the plain of the Litimé. The objective of the present study is to analyze the distribution of the natural populations in the plain of Litimé forest but also natural and artificial regeneration of the species. The perspective is to repeat this experiment with other local species in other regions of Togo in order to diversify the plantations and to protect the local forest biodiversity.

Ecological Sustainability of Detar (<i>Detarium senegalense</i>J. F. Gmel) in Togo (West Africa)

Detarium senegalense J. F. Gmel., of the family of Fabaceae is one of the most exploited tree species in Togo. However, there are only few scientific studies on the distribution of this specie. This study is a contribution to the promotion of multi-purpose tree species in Togo with particular emphasis on a better knowledge of Detarium senegalense. It provides data on the ecology of the specie and his state of regeneration. The data on the specie are based on sample plots in the areas identified as hosts of the specie in Togo. A total of 77 circular plots of 1000 m2 (17.8 m radius) were established in ecological zones II, IV and V of Togo. The dendrometric parameters identified are: the total height and diameter at breast height (DBH) of Detarium senegalense and of all species found in each plot. Detarium senegalense trees of DBH < 10 cm are considered as potential regenerations. Detarium senegalense is more abundant in zones IV (forest area), followed by zone II. In zone V, Detarium senegalense is located only in the forest of “Have”. The structure of Detarium senegalense has a bell-shaped distribution with predominance of trees with large and intermediate diameters ranging between 30 and 70 cm. Trees of small DBH (Detarium senegalense occurs. This indicates a low regeneration rate of the specie. However, the structure of all species inventoried has a negative exponential distribution with predominance of small diameter trees. The sustainable management of Detarium senegalense in the forest can only be secured through a sustainable harvesting of seeds and actives promotion of natural regeneration.

Survival, Growth and <i>Orygmophora mediofoveata</i>Shoot Borer Attack of <i>Nauclea diderrichii</i>Progenies Established in Three Ecological Zones in Ghana

Nauclea diderrichii is a tropical African hardwood species and a suitable candidate for plantation development. However, attack by the Orygmophora mediofoveata, Hamps shoot borer threatens establishment of the species in plantations. A genotype * environment assessment of 15 N. diderrichii progenies from Ghana and Togo was conducted in the Wet Evergreen, Moist Semi-deciduous and Dry Semi-deciduous forest zones. Progeny performance (Attack intensity, survival and growth) varied significantly between sites, and marginally within sites after 2.7 years. Overall, incidence of shoot borer attack was lower at the wet zone than at the moist or dry zones. Percent survival was higher at the wet (79.5%) than at the moist (50.8%) or dry (55.0%) forest zones. Mean height across the 15 progenies was 5.40 m, 4.30 m, and 2.73 m at the wet, dry and moist forests, respectively. Similarly, mean diameter was 5.31 cm, 4.58 cm, and 2.83 cm at the wet, dry and moist zones, respectively. The relatively low growth rate recorded at the moist zone was attributed to the paucity of soil conditions at the experimental site. Three wet forest zone progenies (BS9, BS3 and BS2) and two moist forest zone progenies (BE2 and GA1) performed better than average and have been recommended for planting.

Constraints to Tropical Forest Conservation and Successful Monitoring and Assessment of Land Uses Cover and Change: Do the Forest Definition and Administration Really Matter?

We examine the constraints to conservation and to successful forestlands’ monitoring/assessments in central Togo through GIS spatial analyses and through a critical overview of the current forestry administration’s model. The major findings are that the land classification based on few inventory parameters cannot substitute for “what forest is”, rather these inventory parameters constitute a mean to sound forest management and conservation when relevantly decided. Also as these parameters measured from satellite imagery are supplemented by continuous fine management data they may consistently contribute to the classification of the vegetation cover. This helps to suggest that solution to forest degradation/deforestation, and monitoring/ assessment requires data refinement through local forest management. Else, the actual forestry administration is local communities and indigenous people’s needs biased because it has been negligent of the cultural forestry practices, the major constraints to conservation and the monitoring/assessment of forest lands. As a common pool-resource, the questions relative to forest cannot be addressed at a single environmental concerns level. Interests are multiple and various along the spectrum from the global environment level to the local environmental level that should be accounted for. Thus we recommend a reconsideration of the forestry administration model. What is required are simple policies processes to define forest management plans that promote simultaneously sustainable forest management while accounting for any stakeholder concern, importantly the cultural forestry that addresses specific local communities and indigenous people’s forest related interests.

Linear Panel Data and Farming Cash Flow Analyses to Assess the Causes of Deforestation in the Upper Guinean Forest: Data and Evidence from the Prefectures of the Central Region in Togo

We present a careful quantitative description of land use in central Togo, by constructing farm budgets and analyzing time series data on agricultural production in four prefectures over the time period from 1996 to 2015. One key finding is that higher prices for chemical inputs are associated with more deforestation (as proxied by area in yam production), and correspondingly, greater quantities of chemical inputs applied are associated with less deforestation. This confirms that chemical fertilizers and forest clearing are substitutes and suggests that one path to reducing deforestation is to increase agricultural productivity, and to provide farmer with agricultural risk assistance that covers the farming negative externality costs. This risk assistance may include the coverage for the environmental deterioration costs, and the subsidies to compensate for investments’ cost.

Monitoring of Residual Forest Ecosystems Dynamics in the Mono Biosphere Reserve (Southeast Togo)

The forest ecosystems of the Lacs 2 commune (South-East, Togo) are undergoing severe degradation, which has not yet been documented. This study is carried out in order to assess and quantify the spatio-temporal dynamics of residual forests and to identify the determinants of deforestation in South East Togo. The methodological approach is based on the use of historical aerial photographs from 1976 and drone images from 2019 in addition to field investigations. Several spatial structure indices were also calculated in order to quantify the fragmentation of classes and of the forest landscape. The results show that the forest landscape is changing. The classes of forests, plantations and palm groves show an annual rate of decline of 7.5%, 0.8% and 9.4% respectively while the classes of savannahs, agglomerations, surface water and swamps increased by 16.4%, 0.4%, 0.7% and 0.1%. The results also reveal a high fragmentation within the forest, plantation, surface water and swamp class and moderate fragmentation for the savannah and palm trees classes. At the landscape level, the savannah class is dominant by more than 70%, thus making the landscape little diversified from an ecological point of view. The main driver of deforestation in the study area remains shifting slash-and-burn agriculture. It is accentuated by the establishment of perennial oil palm crops, which has influenced the annual deforestation rate by 0.72%.