Abstract Detail

The evolution of functional traits in plants: is the giant still sleeping?

Mason, Chase [1], LaScaleia, Michael [2], Monroe, J. Grey [3], Goolsby, Eric [4].

Learning from dynamic traits: seasonal shifts inform the origin of ecophysiological trade-offs across scales from macroevolutionary to intra-individual.

Phylogenetic comparative methods provide a powerful approach for assessing evolutionary correlations among functional traits, as well as between traits and environmental factors. Such inferences can uncover trait-trait tradeoffs arising from either selection or constraints on plant form and function, as well as provide evidence of the role of traits in adaptation if there has been repeated independent evolution of certain trait values during the colonization of particular environments. For continuous traits, to date most workers using phylogenetic comparative approaches employ a single trait value per species, often a mean of sampled individuals, and several approaches currently exist to allow the incorporation of intraspecific variation. However, most of these approaches assume that there is a single mean value for each species around which the observations form a distribution, and there are not yet many tools that allow different assumptions. It has been known for quite some time that some of the most physiologically and ecologically important plant traits are actually highly plastic, whether with developmental stage, across a growing season, or in response to environmental conditions. The time scales involved vary dramatically, from minutes to decades. At the very rapid end of the spectrum, imagine the response of photosynthesis to light levels (described by light response curves) or the inducible upregulation of chemical defenses under pest or pathogen attack. At an intermediate timescale, imagine the response of plant biomass allocation to changing soil moisture conditions, or the response of phenological traits to differences in photoperiod or temperature. At the very slow end of the spectrum, imagine the difference in the construction and makeup of plant organs in small seedlings versus adult trees. A very large number of plant functional traits are not fixed, but vary dynamically over time or environmental conditions, and stronger insights into the evolution of plant functional traits can emerge when this dynamism is explicitly incorporated into phylogenetic comparative approaches. Here we demonstrate one possible statistical approach to incorporating dynamic traits in a phylogenetic context, while encouraging the development of better tools in this area. We also highlight several examples of common functional traits and other plant responses across systems where the explicit incorporation of trait dynamism may improve inference, with particular focus on seasonal shifts in leaf economic traits and leaf defenses across the genus Cornus.

Related Links:
Mason Lab
Goolsby Lab
J. Grey Monroe Website

1 - University Of Central Florida, Department Of Biology, 4110 Libra Dr, Orlando, FL, 32816, United States
2 - Tufts University, Environmental Studies, 200 College Avenue, Medford, MA, 02155, USA
3 - Colorado State University, Graduate Degree Program in Ecology, Fort Collins, CO, 80523, USA
4 - University of Central Florida, Department of Biology, 4110 Libra Dr, Orlando, FL, 32816, USA

functional traits
Function-Valued Traits
Intra-Individual Variation
Dynamic Traits
phylogenetic comparative methods

Presentation Type: Colloquium Presentations
Number: 0005
Abstract ID:219
Candidate for Awards:None

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