Le vendredi 20 juin 2014 à 12h45, en salle de conférences de l'OSUR, campus de Beaulieu, bât.
Le vendredi 20 juin 2014 à 12h45
, en salle de conférences de l'OSUR, campus de Beaulieu, bât. 14b, UR1Nutrient enrichment and the intensity of local competition influence the evolution of mineralizationRésumé :
The functioning of ecosystems and their emerging properties depend on the traits of the species they host and these traits evolve because they also influence individual fitness. It is thus important to study how evolution impacts functional traits and to determine how evolutionary outcomes determine ecosystem properties. We tackle this general issue by studying the evolution of plant strategies that affect mineralization by controlling the chemical quality of their own litter with a patially-explicit and individual-based simulation model. Individual plants may die and produce seeds that are dispersed. Mutants appear stochastically with different mineralization strategies. A trade-off is implemented between the rate of nutrient loss from plants and the rate of litter mineralization. Our results suggest that the capacity to influence mineralization is submitted to natural selection and evolves as any other trait. It modifies soil capacity to store organic carbon thereby being relevant in the context of the current climate change and global nutrient enrichment. Indeed, our model shows that evolutionary feedbacks of plants to nutrient enrichment are likely to differ from purely ecological feedbacks.Contact : Sébastien BAROT