Biogeographic transitions as a source of high biological diversity: Phylogenetic lessons from a comprehensive ecotone of South America

• DOI: 10.1016/j.ppees.2020.125528
• Publication Date: 2020-04-04T00:44:12Z
• Authors: Islandia Silva-Pe...; João Augusto Alve...; Vanessa Leite Rez...; Pedro V. Eisenlohr
• Keywords: 0301 basic medicine; 03 medical and health sciences; 13. Climate action; 15. Life on land

Abstract Studies that provide support for the conservation of transitions between biogeographic regions should be encouraged, given the ecological and evolutionary specificities of these environments. Investigations on evolutionary history may, for example, influence the prioritization of areas for biological conservation, as they enable a better understanding of the processes that shape communities in space and time. We used the occurrence data of tree species available for 87 sites of the Cerrado-Amazon Transition from the NeoTropTree database, together with 73 environmental variables, and investigated the phylogenetic structure (overdispersed, clustered, or randomly distributed communities) and diversity in this region. We evaluated the relationship between phylogenetic metrics and environmental variables using generalized least squares models. Our results demonstrated a predominant pattern of phylogenetic overdispersion, as well as high phylogenetic diversity. Phylogenetic metrics were strongly influenced by bioclimatic variables. Our study demonstrates that the Cerrado-Amazon Transition plays a fundamental role in the conservation of the regional flora both in terms of phylogenetic structure and diversity, but the protected areas in this region harbor only a restricted portion of this high diversity. These results not only confirm that transitional environments are areas of high biological diversity, but, unprecedentedly, this observation occurs from phylogenetic analyses of communities and to a biogeographic region so widely distributed and highly impacted by anthropogenic actions. Such findings point to the urgent need to take varied dimensions of biodiversity in establishing new areas of environmental protection in transition zones into account.