Paul V.A. Fine
Tropical rain forests harbor extraordinary numbers of species, dwarfing diversity totals from most extra-tropical regions. The disparities in species richness for trees, my research focus, are especially large. The U.S. and Canada contain about 600 species of trees, while a similar area in the Amazon basin may hold 16,000 or more (ter Steege et al., 2015 Science Advances). The uneven distribution of species diversity across the globe is called the latitudinal diversity gradient, and the mechanisms responsible for the origin and maintenance of a diversity gradient have been the focus of intense debate in biology ever since it was first described in the nineteenth century (Fine, 2015, Annual Review of Ecology, Evolution, and Systematics). My research program aims to contribute to understanding why global diversity gradients exist and why tropical rain forests are so amazingly species rich. As an integrative biologist, I have tackled this problem from a variety of different angles and across geographic and taxonomic scales, employing approaches from community ecology, biogeography, phylogenetics, and population genetics.
Most of my research investigates the origin and maintenance of Amazonian rain forest tree diversity. I am especially interested in the role that biotic interactions and environmental heterogeneity play in the morphological, functional, and genetic diversity of tropical trees, and how these factors influence the distribution of plant species and the process of speciation. An ideal study system is the unique flora found on nutrient-poor white-sand forests that are widely dispersed in patches throughout the Amazon basin. These ancient white-sand deposits constitute habitat islands, surrounded by other terra firme forests on more fertile soils that harbor soil-specialist tree species, which are often closely related to their congeners on neighboring soil types. The main thrust of my research is to understand the evolution and maintenance of edaphic specialization by trees to these divergent soil types, and the role of natural enemies (herbivores and pathogens) in this process. After more than twenty years of studying the phylogeny, systematics, ecology, functional traits, and chemical defenses of Protium (Burseraceae) trees, I have developed Protium into a model system to investigate speciation, biotic interactions, and community assembly.
Facets of my research program include: A) habitat specialization and community assembly of Amazonian tree lineages; B) evolution and historical biogeography of Burseraceae trees; C) interactions of plants and their natural enemies driving chemical defense, community assembly, and diversification.