The Influence of Taxonomy and Environment on Leaf Trait Variation Along Tropical Abiotic Gradients

Imma Oliveras,Lisa Bentley,Theresa Peprah,Gregory Asner,Mickey Boakye,Norma Salinas,Paulo Morandi,Brian J Enquist,Stephen Adu-Bredu,Alexander Frederick Shenkin,Roberta Martin,Sandra Díaz,Karine Silva Peixoto,Ben Hur Marimon Junior,Yadvinder Malhi,Agne Gvozdevaite,Nikolaos M Fyllas,Beatriz Schwantes Marimon

doi:10.3389/ffgc.2020.00018

Abstract

Abstract Deconstructing functional trait variation and co-variation across a wide range of environmental conditions should increase the mechanistic understanding of community assembly processes and improve current parameterization of dynamic vegetation models. Here, we present a study that deconstructs leaf trait variation and co-variation to iithin-species, taxonomic-interspecific, and plot-environment components comparing three tropical environmental gradients in Peru, Brazil and Ghana. We measured photosynthetic, chemical and structural leaf traits using a standardized sampling protocol, totalling more than 1,000 individuals belonging to 367 species sampled. Variation associated with the whole interspecific taxonomic component (species+genus+family) for most traits was relatively consistent across environmental gradients, but intra-specificwithin-species variation and the plot-environment variation was strongly dependent on the environmental gradient. Trait-trait co-variation was also strongly linked to the environmental gradient where the traits were measured, although some traits had consistent co-variation components irrespective of environmental gradient. Our results demonstrate that filtering along gradients is mostly expressed through trait intra- and interspecifictaxonomic variation, but that trait co-variation is strongly dependent on the local environment, and thus global trait co-variation relationships might not always apply at smaller scales.

Highlights

Over the past two decades, functional trait ecology has increasingly been used to understand and predict the structure and functioning of plant communities (Lavorel and Garnier, 2002; McGill et al, 2006)
The variation associated with the plot-environment component contributed 18% of the total trait variation on average, with a maximum of 60% ([Ca] in the elevation gradient) and a minimum of 0.01% (LDMC in the forest-savanna gradient)
We show that: (1) the total amount of withinspecies, taxonomic and plot-environmental variation for a given trait is relatively consistent across environmental gradients; (2) community-weighted mean trait values are not consistently represented across environmental gradients, reflecting the varying strengths of local filtering in each gradient; (3) trait co-variation is strongly scale-dependent and site-dependent, we found that traits associated to the leaf economic spectrum (Asat, Amax, leaf mass per area (LMA), N), and leaf thickness (LT) share a common axis of variation

Summary

Introduction

Over the past two decades, functional trait ecology has increasingly been used to understand and predict the structure and functioning of plant communities (Lavorel and Garnier, 2002; McGill et al, 2006). Functional traits are often measured across contrasting environments (Diaz et al, 1998; Ackerly, 2004; McGill et al, 2006; Anderson et al, 2011) to characterize how the mean community trait value varies within and across spatial scales They are often studied along vegetation continua derived from latitudinal (Shepherd, 1998; Swenson et al, 2012; Lamanna et al, 2014; Lawson and Weir, 2014), climatic (Hulshof et al, 2013), elevation (McCain and Grytnes, 2001; Körner, 2007; Bryant et al, 2008), temporal (Enquist et al, 2015), and vegetation gradients (Fernandes, 2000; Ackerly et al, 2002; Messier et al, 2017)

Methods

Results

Discussion

Conclusion