Prosopis Juliflora Invasion in Baringo, Kenya: Exploring Its Impacts on Lulc Dynamics, Vachellia Tortilis, Selected Ecosystem Services, Livelihoods and Potential Spread Under Climate Change
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Date
2023Author
Mbaabu, Purity Rima
Type
ThesisLanguage
enMetadata
Show full item recordAbstract
Savanna grasslands are invaluable, but face threats from multiple stressors such as land
degradation, woody encroachment and climate change. While it is expected that climatic
changes will continue to exacerbate existing stressors, rapid invasion by woody plants such as
Prosopis juliflora is now widely considered a key factor accelerating degradation in
grasslands. This raises concerns about the functioning and sustainability of these ecosystems.
In the savanna grasslands of Baringo County in Kenya, Prosopis juliflora (hereafter referred
to as “Prosopis”) was introduced in 1982/83 to alleviate firewood shortage and mitigate
desertification. However, it has become invasive and continues to disperse to new areas at
exceptional rates, impacting on the environment, economies and people. This study utilized
various datasets and methodologies to analyze the 1) spatio-temporal changes in Prosopis
coverage in Baringo County since its introduction, 2) implications of these changes on other
land-uses and land-cover, native Vachellia tortilis, livelihoods, biodiversity and selected
ecosystem services (ES), and 3) impacts of current and predicted future climate change on
suitable habitat of alien Prosopis and the dominant native Vachellia tortilis, which is
currently highly threatened by Prosopis invasion. Prosopis spread at a rate of 640 ha / year
between 1988 and 2016, replaced over 30% of other valuable land-uses/land-cover and
caused significant livelihood losses. Further, grassland restoration is as effective as Prosopis
invasion in replenishing soil organic carbon, and does not comprise the provisioning of other
ES, while Prosopis limits fodder productivity and species diversity. Species distribution
models revealed that climate warming will have profound effects on species geographic
ranges of both alien and native species. Climate models predict both habit expansion and
contraction. The adverse effects (habitat encroachment) of invasive plants on biodiversity
will equally persist in the face of the envisaged climatic changes. Over 30% of the predicted
future suitable habitat for Vachellia tortilis is also suitable for Prosopis, indicating possible
invasion into these habitats in future. These findings suggest an integrated approach to
Prosopis management to prevent further spread. Further, effects of climate change should be
mainstreamed in policies addressing invasive species, land degradation and biodiversity loss.
Publisher
University of Nairobi
Rights
Attribution-NonCommercial-NoDerivs 3.0 United StatesUsage Rights
http://creativecommons.org/licenses/by-nc-nd/3.0/us/Collections
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