The Traits Cabaret

natacha.fontaine@sbf.ulaval.ca

Frais d'inscription: Site web: Conférentier: Contact: Global Biogeography of Trees; a Functional Approach Élise Bouchard, étudiante à la maîtrise en biologie, UQAM This project aims to determine which environmental gradients drive the distribution of functional traits in forest communities worldwide. The work will be conducted using data from many international databases, including the GFBi (Global Forest Biodiversity initiative) and TRY. The GFBi is composed of 1,2 million plots and contains values of species abundance. This worldwide coverage provides a great opportunity to test hypothesis which will help us understand assembly rules of forest communities at a global scale. Five different functional traits will be analysed, but this talk will mainly focus on wood density. ________________ Quelle diversité fonctionnelle dans les communautés végétales riveraines aménagées ? Maxime Tisserant, Étudiant au doctorat en biologie végétale, Université Laval Ce projet de doctorat vise à comprendre les patrons de diversité taxonomique et fonctionnelle de berges aménagées pour la stabilisation ainsi que les facteurs environnementaux expliquant la composition des communautés végétales. Les analyses utilisées dans le projet pour explorer la diversité fonctionnelle de communautés végétales seront présentées. _________________ Trait-based understanding of nitrogen fixation and aridity Wenying Liao, Étudiante au doctorat à Princeton University, New Jersey, États-Unis Nitrogen is an essential limiting nutrient across many ecosystems, constraining the capacity of biosphere carbon storage. The main process introducing nitrogen into terrestrial ecosystem is biological nitrogen fixation, where nitrogen-fixing bacteria convert atmospheric dinitrogen gas into plant-available form. Some nitrogen-fixing bacteria are symbiotic with higher plants, and plant tissues enriched with fixed nitrogen can ultimately return to the ecosystems and potentially alleviating local nitrogen limitation. Accurately predicting capacity of such nitrogen flow into the environment is, thus, critical for the improved prediction of global carbon storage capacity. By analyzing large forest inventory data across U.S. and Mexico, I demonstrate the phenomenological relationship between rainfall gradient and abundance of nitrogen-fixing trees, which suggests that nitrogen-fixing trees have competitive advantage under dry conditions. Inspired by the observed pattern, I then build a game-theoretical model to explore the mechanistic underpinnings of the relationship between aridity and nitrogen fixation. Improved understanding of the mechanisms will ultimately allow us to predict future nitrogen fixation capacity under newly-emerging environment with climate change, instead of being constrained by the currently observed range of environment. In this talk, I will share the recent development on a trait-based understanding of nitrogen fixation and aridity.
Natacha Fontaine Coordonnatrice du pôle de Québec Centre d’étude de la forêt (CEF) Local 1122, Pavillon Abitibi-Price Université Laval Québec (Québec), G1V 0A6 Tel : (418) 656-2131 poste 15028
Élise Bouchard (UQAM), Maxime Tisserant (Université Laval) et Wenying Liao (Princeton University)
www.cef-cfr.ca
Gratuit