Browsing by Autor "Miguel N. Alexiades"

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Fast demographic traits promote high diversification rates of Amazonian trees
(Wiley, 2014) Timothy R. Baker; R. Toby Pennington; Susana Magallón; Emanuel Gloor; Susan G. W. Laurance; Miguel N. Alexiades; Esteban Álvarez‐Dávila; Alejandro Araújo; E.J.M.M. Arets; Gerardo A. Aymard C.
The Amazon rain forest sustains the world's highest tree diversity, but it remains unclear why some clades of trees are hyperdiverse, whereas others are not. Using dated phylogenies, estimates of current species richness and trait and demographic data from a large network of forest plots, we show that fast demographic traits--short turnover times--are associated with high diversification rates across 51 clades of canopy trees. This relationship is robust to assuming that diversification rates are either constant or decline over time, and occurs in a wide range of Neotropical tree lineages. This finding reveals the crucial role of intrinsic, ecological variation among clades for understanding the origin of the remarkable diversity of Amazonian trees and forests.
Large range sizes link fast life histories with high species richness across wet tropical tree floras
(Nature Portfolio, 2025) Timothy R. Baker; Stephen Adu‐Bredu; Kofi Affum‐Baffoe; Shin‐ichiro Aiba; Perpetra Akite; Miguel N. Alexiades; Everton Cristo de Almeida; Edmar Almeida de Oliveira; Esteban Álvarez‐Dávila; Christian Amani
Phylogenetic diversity of Amazonian tree communities
(Wiley, 2015) Eurídice N. Honorio Coronado; Kyle G. Dexter; R. Toby Pennington; Jérôme Chave; Simon L. Lewis; Miguel N. Alexiades; Esteban Álvarez‐Dávila; Atila Alves de Oliveira; Iêda Leão do Amaral; Alejandro Araujo‐Murakami
Abstract Aim To examine variation in the phylogenetic diversity ( PD ) of tree communities across geographical and environmental gradients in Amazonia. Location Two hundred and eighty‐three c . 1 ha forest inventory plots from across Amazonia. Methods We evaluated PD as the total phylogenetic branch length across species in each plot ( PD ss), the mean pairwise phylogenetic distance between species ( MPD ), the mean nearest taxon distance ( MNTD ) and their equivalents standardized for species richness (ses. PD ss, ses. MPD , ses. MNTD ). We compared PD of tree communities growing (1) on substrates of varying geological age; and (2) in environments with varying ecophysiological barriers to growth and survival. Results PD ss is strongly positively correlated with species richness ( SR ), whereas MNTD has a negative correlation. Communities on geologically young‐ and intermediate‐aged substrates (western and central Amazonia respectively) have the highest SR , and therefore the highest PD ss and the lowest MNTD . We find that the youngest and oldest substrates (the latter on the Brazilian and Guiana Shields) have the highest ses. PD ss and ses. MNTD . MPD and ses. MPD are strongly correlated with how evenly taxa are distributed among the three principal angiosperm clades and are both highest in western Amazonia. Meanwhile, seasonally dry tropical forest (SDTF) and forests on white sands have low PD , as evaluated by any metric. Main conclusions High ses. PD ss and ses. MNTD reflect greater lineage diversity in communities. We suggest that high ses. PD ss and ses. MNTD in western Amazonia results from its favourable, easy‐to‐colonize environment, whereas high values in the Brazilian and Guianan Shields may be due to accumulation of lineages over a longer period of time. White‐sand forests and SDTF are dominated by close relatives from fewer lineages, perhaps reflecting ecophysiological barriers that are difficult to surmount evolutionarily. Because MPD and ses. MPD do not reflect lineage diversity per se , we suggest that PD ss, ses. PD ss and ses. MNTD may be the most useful diversity metrics for setting large‐scale conservation priorities.