Browsing by Subject "Madagascar"

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    Ecological, Social, And Educational Dimensions Of Restoration: Insights From Berenty Reserve, Madagascar
    (2024) Mondragon, Ariadna
    Amidst a global biodiversity crisis, ecological restoration emerges as a critical solution to mitigate the devastating effects of biodiversity loss and climate change. Focusing on Madagascar, a biodiversity hotspot facing significant forest loss, this dissertation explores various aspects of ecological restoration in the Berenty Reserve. It integrates ecological, social, and educational perspectives to provide applied knowledge and practical insights, addressing the unique challenges of restoring the tropical dry forest. The study includes a comprehensive baseline inventory of the forests in Berenty to characterize a reference ecosystem to set restoration goals in the reserve. I found that the spiny and gallery forests were different structurally and compositionally, requiring tailored restoration interventions. Special attention was given to Tamarindus indica, the tamarind tree, a species critical for the forests of the reserve and its lemurs, but facing regeneration challenges. I conducted three experiments to understand the impacts of light and water availability on its early life history stages, showing that light is the most limiting resource for tamarind growth and that water availability impacts tamarind more than water frequency. I also addressed management alternatives of the invasive vine Cissus quadrangularis. Investigating its desiccation thresholds, I found that C. quadrangularis can remain viable after losing 80% of its mass, concluding that management strategies should ensure complete desiccation of Cissus fragments to prevent its regrowth. Leveraging on my experience in the Berenty Reserve, I developed a decision case study for use in undergraduate or graduate student classrooms, where students grapple with the complexities of choosing between native and non-native plant species for restoring a tropical dry forest. This educational tool enhances the understanding of restoration ecology and motivates broader engagement. Finally, I examined the integration of the social sciences and/or local ecological knowledge within restoration research, highlighting the gap between theoretical advocacy and practical application and indicating the need for more inclusive and interdisciplinary approaches. Collectively, this work contributes valuable practical and theoretical insights aimed at improving restoration strategies, not only for the dry forests in Madagascar but also for similar ecosystems globally.
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    Forest restoration in Eastern Madagascar: Post-fire survival of select Malagasy tree species
    (2018-08) Hill, Donald
    As fire becomes more common in rainforests due to climate change, understanding rainforest tree species’ tolerance to fire becomes increasingly important. Madagascar’s northeast coast is particularly vulnerable to fire given the 20th century invasion of Dicranopteris linearis fern that is extremely flammable, promoting its own dominance in this region. The objective of the study was to investigate which Malagasy tree species were better able to survive a fire disturbance and under what conditions. We planted 4,000 trees of 11 different Malagasy tree species in 160 small monoculture islands consisting of 25 trees each. At this time, we recorded site conditions such as fuel depth, slope, sapling height, and position within the island. Just after the wildfire we scored the intensity and severity of the fire at each of the 4,000 saplings. Several months later during the rainy season, we returned to each of the 4,000 saplings and recorded survival. We found that choice of species and low perimeter:area ratio planting designs are two of the most important factors that determined sapling survival of a wildfire. The timing of outplanting was the third most important choice that required species-specific knowledge of the relative importance of larger sapling size and days of establishment to harden in the field. A number of diverse life history traits also emerged that described how each species was able to survive wildfire. We categorized these into three broad categories: retardance, resistance, resilience. For restoration practitioners worldwide who work amidst highly flammable fuels, our results suggest that at the time of outplanting careful planning for the possibility of subsequent fire disturbances can greatly increase the chance of the project reaching maturity.
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    Madagascar - Sustainable horticulture crop production
    (2010-11-28) Lybeck, Christopher