Ethnobiology and population ecology of neotropical palms
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Palms are ecologically important and charismatic trees of the tropics. They are important to the livelihood of local communities and are key resources for the frugivore community in tropical forests. These frugivores are in turn hunted by humans for food. This ecological connection between human, palms, and frugivores provides a unique setting to study how cultural and ecological components within this multitrophic interaction influences palm populations. In chapter 1, I explored the traditional and ecological knowledge behind the cultivation of palm-weevil larvae for food. I found the Joti people, cultivated two species of weevil-larvae differently, which also determined whether palms were logged before or after reproductive maturity. The cultivation of each weevil-larvae species therefore had a differential impact on palm populations. In chapter 2, I investigated how frugivores mediate interactions between two dominant and co-occuring palms in the Peruvian Amazonia-- Attalea phalerata and Astrocaryum murumuru. I found frugivores codispersed seeds of the two palm species, which contributed to aggregated spatial patterns of their juveniles. Spatial patterns suggested associations between heterospecific palms experienced lower density-dependent mortality than associations between conspecifics and this likely contributes to the coexistence of the two palm species in their early life-history. These findings highlight the importance of dispersers to species coexistence and suggest over-hunting can lead to shifts away from species codominance. In chapter 3, I examined the contribution of dispersal, distance-and density-dependent to spatial ecology of Attalea phalerata. Using microsatellite-based parentage analysis, I found high levels of seed movement mediated by frugivore dispersers. Despite this, I found dispersal limitation remains strong enough to cause spatial aggregation between offspring and parents. As individuals grew towards maturity, distance and density dependent mortality contributed to increasingly disaggregated patterns between older offspring cohorts of parents, non-parent adults, and siblings. These results provide a foundation for assessing the impacts of hunting on the spatial ecology of palm populations. In chapter 4, we characterized 14 microsatellite loci for A. phalerata that were used in the parentage analysis of chapter 3. These loci amplified reliably and were sufficiently polymorphic and will be useful for future studies addressing population-level questions for this species.