Université du Québec à Rimouski
Postdoctoral fellow candidate
Supervisor: Piero Calosi
Dominique Gravel
Start: 2019-11-01
End: 2020-08-31

Project

Quantification of the effects of ecophysiological sensitivity and biotic interactions on the estimation of species extinction rates
Species extinctions are happening at faster rates than ever before, greatly exceeding the rates observed during the five mass extinctions documented in the fossil record. Extinction events are inherently difficult to document because species are usually at very low abundance on the verge of extinction and therefore hard to detect. However, estimating extinction rates is a key element of major biodiversity syntheses such as the IPBES reports. In order to conserve high levels of taxonomic and functional biodiversity in the marine environment, we require methodologies to document and understand extinctions, incorporating the mechanisms that can exacerbate species loss in a time of high-dimensional environmental changes. In particular, species are embedded in complex interaction networks, through which the loss of one species can trigger the disappearance of other species. This in turn, can cause communities collapse and alter the function of ecosystems, upon which services are provided. Current methodologies consider extinctions to be additive because they do not account for secondary extinctions and therefore may largely underestimate global extinction rates. Our main objectives are therefore to develop and test a methodology to document species extinctions from time series of sighting records, accounting for physiological vulnerability to environmental changes and changes in biotic interactions. To accomplish this we will (1) develop a bayesian model to identify extinction events driven by abiotic changes and species interactions, (2) apply the methodology to study extinctions in a marine community subject to an environmental change using laboratory mesocosm experiments, and (3) apply the extinction methodology to fossil records during previous mass extinctions in order to document the occurrence of secondary extinctions in the past. We will do so by implementing a multidisciplinary approach and integrating knowledge from the research fields of community ecology, mechanistic physiology, paleo-ecology and bayesian statistics. This methodology will be applied to determine which combination of biotic and abiotic parameters precedes the decline or loss of even a single keystone species, instigating a cascade of ‘downstream’ extinctions. The application of our methodology to fossil records will help us understand past extinctions and hopefully better anticipate the ones susceptible to happen in the future.

Keywords

Extinction risk, Ecological Networks, Macrophysiologie, Écophysiologie, Species Distribution Model, Changements globaux, biogéographie / biogeography

Publications

1- Effect of conspecifics density on the settlement of Petrolisthes laevigatus (Decapoda: Porcellanidae)
Gebauer, P., M. Freire, A. Barria, K. Paschke
2011 Journal of the Marine Biological Association of the United Kingdom

2- Seasonal variation in dry weight and elemental composition of the early developmental stages of Petrolisthes laevigatus (Guérin, 1835) (Decapoda: Porcellanidae) in the Seno de Reloncaví, southern Chile
Gebauer, P., K. Paschke, A. Barría, K. Anger
2012 Helgoland Marine Research

3- Variabilidad espacial y temporal del suministro larval de mitílidos en el Seno de Reloncaví, sur de Chile
Barria, Aura, Paulina Gebauer, Carlos Molinet
2012 Revista de biología marina y oceanografía

4- Latitude or biogeographic breaks? Determinants of phenotypic (co)variation in fitness-related traits in Betaeus truncatus along the Chilean coast
Barria, Aura M., Marco A. Lardies, Andrew P. Beckerman, Leonardo D. Bacigalupe
2013 Marine Biology

5- Intraspecific geographic variation in thermal limits and acclimatory capacity in a wide distributed endemic frog
Barria, Aura M., Leonardo D. Bacigalupe
2017 Journal of Thermal Biology

6- Thermal physiological traits and plasticity of metabolism are sensitive to biogeographic breaks in a rock-pool marine shrimp
Barria, Aura M., Leonardo D. Bacigalupe, Nelson A. Lagos, Marco A. Lardies
2018 The Journal of Experimental Biology

7- Natural selection on plasticity of thermal traits in a highly seasonal environment
Bacigalupe, Leonardo D., Juan D. Gaitán-Espitia, Aura M. Barria, Avia Gonzalez-Mendez, Manuel Ruiz-Aravena, Mark Trinder, Barry Sinervo
2018 Evolutionary Applications