Abstract Detail


Jantzen, Johanna [1], Carteron, Alexis [2], Laliberté, Etienne [3], Bruneau, Anne [4].

Evolutionary dynamics of leaf spectra: Influence of mycorrhizal associations on leaf spectra in a host evolutionary context.

Spectranomics is an emerging field of research that links the spectral-optical properties of leaves with trait and species diversity. Leaf spectra can be described as integrated foliar phenotypes that capture a wide range of functional traits which can provide insight into ecological processes. It has been proposed that leaf traits, and therefore leaf spectra, may reflect below-ground processes such as mycorrhizal associations. If such a relationship exists, this would enable the remote sensing of underground traits via the spectral properties of canopies, as has been claimed by recent studies. However, evidence for the relationship between leaf traits and mycorrhizal association is mixed, and few studies account for shared evolutionary history when testing these correlations. In this study, the relationship between leaf spectra and mycorrhizal associations was evaluated using leaf spectra for 92 vascular plant species measured through the Canadian Airborne Biodiversity Observatory. We modeled the evolution of leaf spectra and used phylogenetic comparative methods, implemented in a penalized likelihood framework for these highly dimensional data, to assess whether species associated with arbuscular mycorrhizas differ in spectral properties from species associated with ectomycorrhizas. We found that spectra evolve under the Ornstein-Uhlenbeck model with a phylogenetic half-life of approximately 48 million years, indicating that there is fairly strong selection on leaf spectra, as expected for an integrated phenotype of functional traits. Based on multivariate models of the high-dimensional spectral data, we found that arbuscular mycorrhizas and ectomycorrhizas do not differ in spectral properties after accounting for phylogeny. However, we found that individual axes of variation representing specific spectral regions capture the variation in mycorrhizal association in our dataset. Univariate models identify multiple optima corresponding with mycorrhizal association, suggesting that arbuscular and ectomycorrhizal plant species experience different selective regimes resulting in different spectral properties at these wavelengths. In conclusion, we demonstrate that although full spectra are not closely linked with mycorrhizal association, specific regions can be linked to the type of mycorrhizal association, enabling the use of these spectral regions to identify underground traits using remote sensing technology.

1 - Université De Montréal, IRBV, 4101 Sherbrooke St E, Montreal, QC, H1X 2B2, Canada
2 - Università degli Studi di Milano, Dipartimento di Scienze e Politiche Ambientali, Milano, Italia
3 - Université de Montréal, Institut de Recherche en Biologie Végétale, 4101 Sherbrooke St E, Montréal, QC, H1X 2B2, Canada
4 - Insti De Recherche Bio Vegetal, 4101 Rue Sherbrooke Est, Montreal, H1X 2B2, Canada

Phylogenetic comparative methods

Presentation Type: Oral Paper
Number: EC11006
Abstract ID:211
Candidate for Awards:None

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