Incongruent Spatial Distribution of Taxonomic, Phylogenetic, and Functional Diversity in Neotropical Cocosoid Palms

Cintia Freitas,Fernanda T Brum,Christine D Bacon,Cibele Cássia-Silva,Leandro Maracahipes,Marcos B Carlucci,Rosane G Collevatti

doi:10.3389/ffgc.2021.739468

Abstract

Biodiversity can be quantified by taxonomic, phylogenetic, and functional diversity. Current evidence points to a lack of congruence between the spatial distribution of these facets due to evolutionary and ecological constraints. A lack of congruence is especially evident between phylogenetic and taxonomic diversity since the name and number of species are an artificial, yet commonly used, way to measure biodiversity. Here we hypothesize that due to evolutionary constraints that link phylogenetic and functional diversity, areas with higher phylogenetic and functional diversity will be spatially congruent in Neotropical cocosoid palms, but neither will be congruent with areas of high taxonomic diversity. Also, we hypothesize that any congruent pattern differs between rainforests and seasonally dry forests, since these palms recently colonized and diversified in seasonally dry ecosystems. We use ecological niche modeling, a phylogenetic tree and a trait database to test the spatial congruence of the three facets of biodiversity. Taxonomic and phylogenetic diversity were negatively correlated. Phylogenetic and functional diversity were positively correlated, even though their spatial congruence was lower than expected at random. Taken together, our results suggest that studies focusing solely on large-scale patterns of taxonomic diversity are missing a wealth of information on diversification potential and ecosystem functioning.

Highlights

Understanding why and how biodiversity is distributed across space is fundamental to preventing its loss in an ever-changing world
We assessed the spatial congruence between taxonomic (TD), phylogenetic (PD), and functional diversity (FD) for the whole cocosoid palm distribution and between rainforests and seasonally dry ecosystems using a Geographically Weighted Correlation (GWC) with the function lcorrel implemented in the lctools package (Kalogirou, 2017)
We hypothesized that phylogenetic and functional diversity have congruent spatial distributions that contrast with the spatial distribution of taxonomic diversity (H1), and that this pattern would differ between rainforests and seasonally dry forests for Cocoseae palms (H2)

Summary

INTRODUCTION

Understanding why and how biodiversity is distributed across space is fundamental to preventing its loss in an ever-changing world. The use of taxonomic diversity as the single source of information might be insufficient in describing how biodiversity patterns vary across space since high species richness does not necessarily lead to greater evolutionary and functional diversity (Sobral et al, 2014; Dreiss et al, 2015), and on top of that, the different components of biodiversity may not even be spatially congruent (Lamoreux et al, 2006). In order to prevent biodiversity loss, it is paramount to understand spatial variation of phylogenetic relationships and functional traits since they represent facets of biodiversity that are not incorporated in species richness (Diniz-Filho et al, 2013, 2019). We leverage the evolutionary history and life history traits of a widespread and species-rich group of palms measured at different evolutionary scales to determine how taxonomic, phylogenetic, and functional diversity interact across space. Incongruences amongst biodiversity metrics mean that the conclusions based solely on taxonomic diversity lack evolutionary and ecological information and inaccurately portrays how biodiversity varies across space

MATERIALS AND METHODS

RESULTS

DISCUSSION

Findings

DATA AVAILABILITY STATEMENT