Current Research

Assessing species vulnerability to climate change

As the magnitude and speed of climate change accelerates, greater understanding of the taxonomy and geography of climatic vulnerability is required to guide effective conservation action. How we will get there? One potential route is to use trait- and phylogenetic-based approaches to quantify the three facets of climate change vulnerability – climate exposure, intrinsic sensitivity and adaptive potential – across multiple species and regions.

Comte L. & Olden J.D. (2017) Climatic vulnerability of the world's freshwater and marine fishes. Nature Climate Change, 7: 718–722. adobe-acrobat-logo
Comte_Figure_risk_two_panelsRisk that freshwater (top) and marine (bottom) fishes could exceed their thermal limits by 2070s. Blue indicates a low risk and red shows a high risk.

Ecological and evolutionary mechanisms shaping species niches

Understanding how phylogenetic constraints and eco-evolutionary forces shape species niches and functional roles is critical for both theoretical and conservation purposes. With intense scrutiny, however, the degree of conservatism in species’ niches is also the subject of considerable debates. This is probably not surprising given that ecological niche is a fairly abstract – but by essence multidimensional – concept. Conservatism of different aspects of species niches and related traits are thus needed to understand the processes driving the spatial (re)distribution of  species.

Comte L., Cucherousset J. & Olden J.D. (2017) Global test of Eltonian niche conservatism of nonnative freshwater fish species between their native and introduced ranges. Ecography, 40: 384–392.adobe-acrobat-logo

Screen Shot 2017-02-24 at 14.47.41.pngTrophic niche shifts between the introduced and native species' ranges within the δ13C and δ15N isotopic space.

Species’ responses to recent climate change

Distribution shifts poleward and upward in elevation are one of the main expected responses of species to climate change, as species attempt to track their favorable climate niche across space. In this context, my work seeks to assess how climate change and the potential interacting effects of other anthropogenic disturbances have affected the spatial distribution of species over the last decades. As a better understanding of the processes of range shifts are needed to be able to predict the vulnerability of species to future climate change, I am also interested in understanding how the ecological and evolutionary characteristics of species are linked to the observed distributional changes.

Comte L., Murienne J. & Grenouillet G. (2014). Species traits and phylogenetic conservatism of climate-induced range shifts in stream fishes. Nature Communications, 5: 5023, 10.1038/ncomm6053. adobe-acrobat-logo

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Theoretical expectations about the underlying mechanisms of range shifts in ectotherms.