Print PageThe combined effects of deforestation and climate change threaten to greatly reduce the extent of rainforest in the Amazon basin and drastically reduce the range size of many rainforest species. Because the primary determinant of species’ extinction risk is range size, closely related species having similar range sizes should lead to significant phylogenetic signal for extinction risk. This in turn could indicate that more phylogenetic diversity will be lost when at-risk species go extinct than would be expected under random extinction. We explore range size and extinction risk among Amazonian tree species and how they vary across the largest phylogeny constructed to date for Amazonian trees.
Results/Conclusions
We find that there will be a great increase by 2050 in the number of at-risk species given current rates of deforestation. Furthermore, there is significant phylogenetic signal for current and projected range size and extinction risk. Thus suggests, importantly, that phylogenies can be a useful tool for estimating the extinction risk of poorly known Amazonian tree species. However, under a variety of quantifications of extinction risk, this does not translate into a greater loss of phylogenetic diversity than expected by chance. This is because most clades contain at least one species with a large range and because high-risk taxa are not disproportionately represented on long terminal phylogenetic branches.
