Perspectivas Macroecológicas Nas Áreas Úmidas Dominadas Por Mauritia Na Amazônia

Abstract

The palm genus Mauritia L.f (Arecaceae) is a principal component of Neotropical freshwater swamp and flooded-savanna vegetation. As such, these palms indicate near-permanent waterlogging at or near ground surface. In this study, expeditionary and exploratory research was undertaken to sample the woody vegetation communities of Mauritia-dominated wetlands (MDWs). A total of 28 MDWs were quantitatively sampled in the Brazilian and Peruvian Amazon. Field work resulted in >3000 botanical collections accompanied by >8000 photographic images made publically available through online resources (http://atrium.andesamazon.org/). Over 40,000 individual woody stems were documented, distributed among 89 families, 318 genera and ~750 woody species. Taking advantage of the indicator status of Mauritia for near-permanently waterlogged substrates – an extreme abiotic condition in the region - the community ecology of woody vegetation of this common Amazonian wetland habitat was investigated across a broad spatial scale regarding its taxonomic, phylogenetic, and biogeographic structure. Data indicate reduced local site richness in MDW vegetation communities, consistent with previous investigation. Over broad spatial scales results show that rather than being comprised of a predictable set of habitat specialists, MDWs exhibit high site-to-site compositional variability relative to surrounding upland forest vegetation. Community phylogenetic analyses reveal that the ability to occupy MDWs is widely distributed in a phylogenetically diverse array of Amazonian forest taxa. Biogeographic analyses reveal that assemblages demonstrate consistent patterns of compositional turnover along local stress gradients, transitioning from largely Amazonian-distributed lineages in forested sites to increasingly extra-Amazoniandistributed lineages in shrubby sites. I suggest that traditionally perceived patterns of community homogeneity of MDWs occur alongside previously underappreciated patterns of taxonomic, phylogenetic, and functional diversity. Taking the results together, I argue that comparative analyses of MDW communities offer unique insight into current models of Amazonian plant and ecosystem diversity that are based almost completely on upland forests, contributing to both Amazonian biodiversity theory (Chapter 1 and 2) and applied science (Chapter 3).