6 research outputs found
Ecological challenges for the buffer zone management of protected areas of forest-savannah mosaic in West Africa
In sub-Saharan Africa, the management of buffer zones around protected areas does not often take into serious account the needs of resource exploitation by the local populations or the conservation needs of these areas. We described the ecological characteristics and management issues affecting the buffer zone around the Fazao-Malfakassa National Park; a 192,000-ha protected area in central-western Togo of utmost conservation importance within the Dahomey Gap region. Within the buffer zone (10 km radius, 334,800 ha), we focussed on four high conservation value areas totalling 65,594 ha (20% of the total buffer zone area). Using 2015 sentinel-2 images we analyzed land cover patterns and described existing ecological zones. We complemented these with field surveys and interviews with 300 people living in 22 villages within the buffer zone to describe the conditions affecting the resident human population. Although over 60% of the total buffer zone area is degraded, we identified four areas of high conservation value (total area = 65,594 ha). Interviewees recognized that slash-and-burn was the most common form of land use, followed by agroforestry practices. Agriculture, charcoal, and firewood production were the main drivers affecting habitats, and land conflicts were recurrent due to the rise in human population. The decline in agriculture, reported by interviewees in some sectors, was attributable to ravages of crops by elephants. Three independent diversity indices showed that, in preserved zones, a greater diversity of animals (with similar utilization frequencies) were hunted than in degraded sites (where grasscutters were the dominant hunted species). There were also significant differences between degraded and preserved zones in terms of plants used for charcoal production and for non-timber forest products. We advocate the development of community-controlled hunting areas to enhance the conservation value of the four well-preserved zones. Instead, promoting sustainable agricultural production systems in the degraded areas can help to further stabilize the agricultural front and reduce land pressure on the park
Changes in the West African forest-savanna mosaic, insights from central Togo.
The West African forest-savanna mosaic, an important habitat for biodiversity and humans, is severely degraded, fragmented and modified by human activities. However, few studies have quantified the land cover changes observed over time and/or analysed the drivers of change. This study focused on Fazao-Malfakassa National Park, the largest in Togo, uses a combination of remote sensing, ground surveys and questionnaires to: (i) quantify vegetation changes, (ii) determine the drivers of change, (iii) compare results with findings elsewhere in the region and (iv) suggest management interventions. The images used were Landsat 5 TM, Landsat 7 ETM and Sentinel-2. Different vegetation indices were computed including: number of fragments, index of dominance, mean area of a vegetation type and mean annual expansion rate. In total, 300 people (including park staff and local populations) were interviewed using a semi-structured questionnaire. Results indicate that between 1987 and 2015 closed-canopy forest and tree-savanna became severely degraded and fragmented, following trends in other parts of the West African forest-savanna mosaic. The main drivers of change were agricultural expansion, bush fires and timber extraction. Observed changes and drivers altered with time: e.g. agricultural expansion was greatest during 1987-2001 (linked with political instability) while illegal timber extraction augmented during 2001-2015 (following increased timber value). Park staff and local populations' perceptions on drivers of change did not differ. Our study highlights that action is urgently needed if we are to preserve this important habitat, the biodiversity it hosts and the services it provides to humans. We suggest several management interventions, learning from successful interventions elsewhere in the region
Ecological drivers of pteridophyte diversity and distribution in Togo (West Africa)
International audienceThe conservation and sustainable management of biodiversity requires an understanding of the biotic and abiotic factors that condition the presence and survival of organisms in natural habitats. The global distribution and ecological hypersensitivity of pteridophytes have made them ideal candidates for studying the impact of biotic and abiotic factors on levels of biodiversity.This study aims to determine the effect of vegetation cover, human disturbance, and climatic factors on the distribution and diversity of pteridophytes in Togo with a view to guide conservation efforts. Our data comprises 130 plots of 500 m2 representing all ecological zones of the country, complemented by several opportunistic collections. After determining the patterns of pteridophyte distribution, multivariate analysis of variance and the calculation of diversity indicators made it possible to determine the influence of the factors studied.We found that pteridophyte species diversity and distribution in Togo are strongly influenced by climatic variables, with more than 90% of species diversity being concentrated in the submontane forest areas. Humidity related variables, insolation, and human disturbances are the main drivers of their distribution. Species diversity is positively associated with an increase in humidity, but decreases with increasing insolation and human disturbance. Importantly, our results emphasize the association of specific species to particular conditions created by climate, land cover, and human disturbances, highlighting the role of pteridophyte species as indicators of environmental conditions or exposure to stress. Within humid forest areas, our analysis of the impact of disturbance indicates that about a quarter of the pteridophyte flora of humid forests is sensitive to minor disturbances, whereas almost all rainforest species decline in the face of high levels of disturbance. Agroforests are a particular case of moderately disturbed rainforests, and have the potential to harbour at least 30.5% of Togolese rainforest pteridophyte species diversity.We conclude that the conservation of pteridophytes in Togo requires the protection of submontane rainforests and the adoption of less destructive practices in terrestrial species habitats in coffee/cocoa-based agroforests
Wind dispersed tree species have greater maximum height
AimWe test the hypothesis that wind dispersal is more common among emergent tree species given that being tall increases the likelihood of effective seed dispersal.LocationAmericas, Africa and the Asia‐Pacific.Time period1970–2020.Major taxa studiedGymnosperms and Angiosperms.MethodsWe used a dataset consisting of tree inventories from 2821 plots across three biogeographic regions (Americas, Africa and Asia‐Pacific), including dry and wet forests, to determine the maximum height and dispersal strategy of 5314 tree species. A web search was used to determine whether species were wind‐dispersed. We compared differences in tree species maximum height between biogeographic regions and examined the relationship between species maximum height and wind dispersal using logistic regression. We also tested whether emergent tree species, that is species with at least one individual taller than the 95% height percentile in one or more plots, were disproportionally wind dispersed in dry and wet forests within each biogeographic region.ResultsOur dataset provides maximum height values for 5314 tree species, of which more than half (2914) had no record of this trait in existing global databases. We found that, on average, tree species in the Americas have lower maximum heights compared to those in Africa and the Asia Pacific. The probability of wind dispersal increased significantly with tree species maximum height and was significantly higher among emergent than non‐emergent tree species in both dry and wet forests in all three biogeographic regions.Main conclusionWind dispersal is more prevalent in tall, emergent tree species than in non‐emergent species and may thus be an important factor in the evolution of tree species maximum height. By providing the most comprehensive dataset so far of tree species maximum height and wind dispersal strategies, this study paves the way for advancing our understanding of the eco‐evolutionary drivers of tree size