Document Type
Dissertation - Open Access
Award Date
2018
Degree Name
Doctor of Philosophy (PhD)
Department / School
Geospatial Science and Engineering
First Advisor
Michael C. Wimberly
Keywords
fire regimes, forest reserves, forest resilience, Ghana, tropical forest fire, Upper Guinean region
Abstract
The Upper Guinean region of West Africa is home to some of the most globally significant tropical biodiversity hotspots, providing ecosystem services that are crucial for the region’s socio-economic and environmental wellbeing. Nonetheless, following decades of human-caused destruction of natural habitats, protected areas currently remain the only significant refugia of original vegetation relics in landscapes that are highly fragmented. Aside from having strong geographic variation in land use, climate, vegetation, and human population, the region has also experienced remarkable biophysical and socio-economic changes in recent decades. All these factors influence the fire regime and the vulnerability of forests within protected areas to fire-mediated changes and forest loss, yet little is known about fire regimes and fire-vegetation interactions within the region. Therefore, the overarching goal of this dissertation was to improve our understanding of the interactions of climate, land use, and fire regimes, as well as effects of fire on forest resilience in the Upper Guinean region of West Africa. I conducted the first comprehensive regional analysis of the fire regime across the gradient from humid tropical forests to drier woodlands and woody savanna. This analysis revealed that different components of the fire regime were influenced by different environmental drivers. As a result, the various combinations of these environmental factors create distinctive fire regimes throughout the region. The results further showed increasing active fire trends in parts of the forested areas, and decreasing trend in fire activity across much of the savannas that were likely linked with land cover changes. An analysis of fire-vegetation interactions in the forest zone of Ghana provided evidence of alternative stable states involving tropical forest and a novel non-forest vegetation community maintained by fire-vegetation feedbacks. Furthermore, an analysis exploring recent drought-associated wildfires in the forest zone of Ghana revealed widespread fire encroachment into hitherto fire-resistant moist tropical forests, which were associated with forest degradation. These findings suggest that ongoing regional landscape and socio-economic changes along with climate change will lead to further changes in the fire regimes and forest vegetation of West Africa. Hence, efforts to project future fire regimes and develop regional strategies for adaptation will require an integrated approach, which encompasses multiple components of the fire regime and consider multiple drivers, including land use and climate. Furthermore, projections of future vegetation dynamics in the region will need to consider land use, vegetation, fires, and their dynamic landscape-scale interactions in the context of broader responses to climate change and human population growth. Overall, this dissertation produced novel results about the pathways and drivers of disturbance land cover change that are necessary for improving our understanding of ongoing changes in a lesser-known part of the tropics. These findings are also relevant for predicting and mitigating similar fire impacts in tropical forests worldwide.
Library of Congress Subject Headings
Fragmented landscapes -- Africa, West.
Forests and forestry -- Environmental aspects -- Africa, West.
Forests and forestry -- Risk management -- Africa, West.
Forest management -- Environmental aspects -- Africa, West.
Climatic changes -- Africa, West.
Forests and forestry -- Fire management -- Africa, West.
Forest degradation -- Environmental aspects -- Africa, West.
Deforestation -- Environmental aspects -- Africa, West.
Description
Includes bibliographical references
Format
application/pdf
Number of Pages
173
Publisher
South Dakota State University
Recommended Citation
Dwomoh, Francis Kwabena, "Vulnerability of Protected Areas to Human Encroachment, Climate Change and Fire in the Fragmented Tropical Forests of West Africa" (2018). Electronic Theses and Dissertations. 2433.
https://openprairie.sdstate.edu/etd/2433
Included in
Forest Sciences Commons, Physical and Environmental Geography Commons, Remote Sensing Commons, Terrestrial and Aquatic Ecology Commons
Rights Statement
