It is estimated that the Amazon forest contains more tree species diversity in per square kilometer than do all temperate forests of Europe, North America, and Asia combined. It is just an example of the wondrous biological diversity of the Neotropics. But, what are the processes and mechanisms that drive this biological richness? It is one of the questions that the new book "Neotropical diversification: Patterns and Processes" (Springer) aims to answer. The book is edited by Valentí Rull, ICTJA-CSIC researcher, and Ana Carolina Carnaval, Molecular Ecology professor in the City University of Nueva York.
The book provides a range of potential explanations of the Neotropical biodiversity origin and maintenance, emphasizing, according to Valentí Rull, “the geological time of the species origin (Paleogene, Neogene, Quaternary). It also talks about the environmental factors that have influenced the diversification (Continental drift, orogenesis, climate changes) and the underlying ecological and evolutionary mechanisms”.
From a “holistic” point of view, the book is aimed to offer to the reader, in just a single volume, a comprehensive overview of the patterns, processes and mechanisms that control diversification (the balance between speciation and extinction) in the different biomes in the area. "This book covers the entire Neotropical region, situated between the Tropics of Cancer and Capricorn, and considers all potential explanations of about the origin of biodiversity in this region", said valentí Rull.
The book focuses on the Neotropics; a large area made up of numerous biomes. "The Amazon Basin is as large as Europe, and no one would think that European biodiversity, as a whole, has a single cause. In addition, Central America, the Caribbean islands, the Orinoco Basin, the Andes and many other regions must be added. The Neotropic is a vast and heterogeneous area defined by different physiographic, topographic, climatic, biotic or ecological drivers”, explained Valentí Rull.
Almost one hundred researchers from different fields such as tropical biology, molecular ecology, climatology, paleoecology, geology or geography, among many others, have written outstanding collections of essays, synthetic analyses and novel investigations. These contributions describe and improve the understanding of the biodiversity of this unique region, an editorial commission from Springer to Valentí Rull.
This multidisciplinary approach aims and allows to determine the ecological and evolutionary mechanisms controlling the diversification. "The fossils and the molecular phylogenies of DNA provide us a good evidence of the age of origin of the species and their geographical patterns and give us clues about the environmental drivers involved, but from here to identify the ecological and evolutionary mechanisms there is a large gap", Rull explains.
The book is subdivided into three parts and contains 30 chapters.
The first part, composed of 8 chapters, offers “global vision of the entire Neotropics to see if there are common processes and mechanisms of diversification” using the general databases available.
The following 12 chapters of the second part, is focused on more specific Neotropical regions and on the specific biomes that have their own dynamics such as the Amazon basin, the Atlantic rainforests, the Mexican forests or the Caribbean islands.
The third section of the book has eight chapters, includes studies devoted to a particular taxonomic group and its diversification histories such as amphibians, reptiles, birds and plants on specific Neotropical areas such as Guayanan and the Andean highlands, or selected river catchments.
The epilogue is dedicated to the conservation of Neotropical biodiversity and compiles several conservation messages discussed throughout the volume. Neotropical diversity already suffers the consequences of human activities that have caused the disappearance of some habitats and biological corridors. According to Valentí Rull, this impact is being also manifested indirectly in the "global warming that may provoke a significant change in weather patterns, especially a general reduction in rainfall and the aridification of many areas”.
"In high mountain areas, such as the Tropical Andes, with altitudes between 5000 and 6000 meters global warming may eliminate the habitats of many species that will not find where to migrate to survive”, concluded Rull.
Rull, V., Carnaval, A. C. (Eds.)(2020). Neotropical Diversification: Patterns and Processes. Springer, Berlin. ISBN 978-3-030-31166-7. https://doi.org/10.1007/978-3-030-31167-4