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

Abstract

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.

Three eco‐physiological strategies of response to drought maintain the form and function of a tropical montane grassland

“…ontology, seasonality, acclimation; Bartlett et al., 2014) and spatial scales (e.g. ecotypes; Oliveras et al., 2020), as well as, biotic interactions (e.g. Chacón‐Labella, de la Cruz, Pescador, & Escudero, 2016) could alter species eco‐physiological strategies and their contribution to key community and ecosystem properties.…”

Long-term droughts may drive drier tropical forests towards increased functional, taxonomic and phylogenetic homogeneity

“…The following traits from the leaf, hydraulics and wood economics spectrum were collected: LA:SA, potential stem specific conductivity (kp), vessel lumen fraction (VLF), vessels diameter (VD), vessel density (pV), leaf area (Area L ), specific leaf area (SLA), leaf nitrogen(N L ) and phosphorus (P L ) content, leaf thickness (Thickness L ), photosynthetic capacity at maximum carbon assimilation rates (A max ) and at light saturated carbon assimilation rates (A sat ), adult maximum height (Height max ), wood density (WD), phenology, guild and nitrogen fixing capacity (Supplementary Table 2). For a fuller description on the field trait sampling see Oliveras et al 68 . The GEM traits dataset is the core trait data used in this study and covered at least 70% of the basal area at the genus level for most plots ( Supplementary Fig.…”

Partitioning of Environmental and Taxonomic Controls on Brazilian Foliar Content of Carbon and Nitrogen and Stable Isotopes

“…The response variables (foliar properties) were modeled assuming the following random variables within the GLMM: (i) species, nested within genus and family; and (ii) site, to account for environmental filters. Adopting the same nomenclature as that found in previous studies (Fyllas et al, 2009;Asner and Martin, 2016;Oliveras et al, 2020), the total variance of the model for each response variable was then partitioned as follows:…”

“…The uniqueness of the Fabaceae family highlights the importance of understanding the taxonomy of plant species and their role on nutrient flow and ecosystem functioning. Taxonomy-driven variances have been reported as a strong source of the variation of photosynthetic and structural traits (Oliveras et al, 2020). Additionally, taxonomy seems to be more limiting to leaf traits than the environment, showing the dominance of taxonomic turnover over the environmental variations (Fyllas et al, 2009;Anderegg et al, 2018;Oliveras et al, 2020).…”

“…Taxonomy-driven variances have been reported as a strong source of the variation of photosynthetic and structural traits (Oliveras et al, 2020). Additionally, taxonomy seems to be more limiting to leaf traits than the environment, showing the dominance of taxonomic turnover over the environmental variations (Fyllas et al, 2009;Anderegg et al, 2018;Oliveras et al, 2020). Many plant traits and associations between traits have been hypothesized to be under the control of a common genetic mechanism, reflecting a combination of evolutionary and community assembly process responding to biotic and abiotic constraints (Chapin et al, 1993;Vasseur et al, 2012;Oliveras et al, 2020).…”