Dispersal assembly of rain forest tree communities across the Amazon basin

Abstract

We investigate patterns of historical assembly of tree communities across Amazonia using a newly developed phylogeny for the speciesrich neotropical tree genus Inga. We compare our results with those for three other ecologically important, diverse, and abundant Amazonian tree lineages, Swartzia, Protieae, and Guatteria. Our analyses using phylogenetic diversity metrics demonstrate a clear lack of geographic phylogenetic structure, and show that local communities of Inga and regional communities of all four lineages are assembled by dispersal across Amazonia. The importance of dispersal in the biogeography of Inga and other tree genera in Amazonian and Guianan rain forests suggests that speciation is not driven by vicariance, and that allopatric isolation following dispersal may be involved in the speciation process. A clear implication of these results is that over evolutionary timescales, the metacommunity for any local or regional tree community in the Amazon is the entire Amazon basin.Amazonia | biogeography | community assembly | phylogenetic structure | tropical trees

Macroevolutionary patterns in overexpression of tyrosine: An anti‐herbivore defence in a speciose tropical tree genus, Inga (Fabaceae)

“…Leaf samples of representative individuals of each species were dried in silica and later extracted and DNA sequenced to confirm species delineations and to place species in a phylogenetic context. Previous phylogenetic work on Inga , using 6,000+ base pairs from seven chloroplast DNA loci and one nuclear locus (nuclear ribosomal internal transcribed spacers), generated through Sanger sequencing, resulted in a poorly resolved phylogeny with multiple polytomies (Dexter et al, ; Kursar et al, ; Richardson et al, ). We therefore employed transcriptome data from three Inga species to design a bait‐capture set that targeted 264 nuclear loci for enrichment from whole‐genome libraries for subsequent sequencing (Nicholls et al, ).…”

“…Inga has over 300 described species (Pennington, ) and appears to have explosively radiated ~9 million years ago (Richardson, Pennington, Pennington, & Hollingsworth, ). Furthermore, in any given forest, it is one of the most diverse genera and one of the most abundant in terms of individual plant stems (Dexter et al, ; Valencia et al, ). For Inga , as with most tropical species, herbivores prefer to feed on expanding leaves, as these are low in fibre and high in nutrients—two unavoidable consequences of growth (Coley, Endara, & Kursar, ).…”

Evaluating the contribution of dispersal to community structure in Neotropical passerine birds

“…Understanding the relative contributions of in situ speciation and dispersal in shaping different communities has been greatly aided by the use of phylogenetic data (reviewed by Tucker et al ). Phylogenetic data can help separate the two processes by providing the shared ancestry for a range of taxa.…”

“…Recent studies on the South American biota suggest that the paradigm regarding how communities are shaped to be shifting away from the influence of biogeographic and climatic processes (Robinson et al , Herzog and Kattan , Ribas et al ) to dispersal being the main driver of diversification and community assembly (Smith et al , Dexter et al , Oliveira et al ). Dispersal ability is expected to positively correlate with diversification rate if it facilitates colonization of new areas and the crossing of geographic barriers (Claramunt et al , Weeks and Claramunt ).…”

Incorporating phylogenetic information for the definition of floristic districts in hyperdiverse Amazon forests: Implications for conservation

“…This suggests a potential scenario in which parapatric speciation might be a general process shaping Amazon forest composition. Nonetheless, current evidence suggests that allopatric speciation after dispersal might be a major evolutionary driver of speciation in Amazon tree lineages (Dexter et al., 2017). Therefore, it will be important to carry out subsequent research at clades levels to elucidate whether these can be considered general mechanisms for the formation of species pool in Amazonian forests (Fine & Baraloto, 2016).…”