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

Deconstructing functional trait variation and co-variation across a wide range of environmental conditions is necessary to 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 into within-species, taxonomic-, and plot-environment components along three tropical environmental gradients in Peru, Brazil, and Ghana. To do so, we measured photosynthetic, chemical, and structural leaf traits using a standardized sampling protocol for more than 1,000 individuals belonging to 367 species. Variation associated with the taxonomic component (species + genus + family) for most traits was relatively consistent across environmental gradients, but within-species variation and plot-environment variation was strongly dependent on the environmental gradient. Trait-trait co-variation was strongly linked to the environmental gradient where traits were measured, although some traits had consistent co-variation components irrespective of gradient. Our results demonstrate that filtering along these tropical gradients is mostly expressed through trait taxonomic 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 and may quickly change under future climate scenarios. Fil: Oliveras, Imma. University of Oxford; Reino Unido Fil: Bentley, Lisa. Sonoma State University; Estados Unidos Fil: Fyllas, Nikolaos M.. University Of The Aegean; Grecia Fil: Gvozdevaite, Agne. University of Oxford; Reino Unido Fil: Shenkin, Alexander Frederick. University of Oxford; Reino Unido Fil: Peprah, Theresa. Forestry Research Institute Of Ghana; Ghana Fil: Morandi, Paulo. Universidade Federal do Mato Grosso do Sul; Brasil Fil: Peixoto, Karine Silva. Universidade Federal do Mato Grosso do Sul; Brasil Fil: Boakye, Mickey. Forestry Research Institute Of Ghana; Ghana Fil: Adu-Bredu, Stephen. Csir - Forestry Research Institute Of Ghana; Ghana Fil: Schwantes Marimon, Beatriz. Universidade Do Estado de Mato Grosso; Brasil Fil: Marimon Junior, Ben Hur. Universidade Do Estado de Mato Grosso; Brasil Fil: Salinas, Norma. Pontificia Universidad Católica de Perú; Perú Fil: Martin, Roberta. Arizona State University; Estados Unidos Fil: Asner, Gregory. Arizona State University; Estados Unidos Fil: Díaz, Sandra Myrna. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Enquist, Brian J.. University of Arizona; Estados Unidos Fil: Malhi, Yadvinder. University of Oxford; Reino Unido