20/09/19 - Séminaire de Matty P. BERG (Vrije Universiteit Amsterdam)
Le vendredi 20 septembre 2019 à 13h00, salle de conférences de l'OSUR, bâtiment 14b, Campus de Beaulieu, UR1
Predicting ecosystem process responses to climate change using the response-to-effect trait framework
One ecologically important aspect of climate change is the increase in frequency and duration of extreme events. These climate events, such heat waves, dry spells or flooding have a larger impact on interacting organisms and ecosystems than gradual changes in the average climate. One of the Herculean tasks we face as ecologists is to understand and predict how climate change will impact the community of functional important organisms, such as soil fauna, and how shifts in community composition affect ecosystem processes.
It has been proposed that ecological generality will improve with a shift from a nomenclatural approach focusing on species number and identity to a more functional approach focusing on species’ functional traits. Trait-based approaches can strongly reduce context dependency. We used a response-to-effect trait framework to understand how precipitation-induced changes in soil moisture conditions affect plants, plant litter, soil fauna and their effect on litter decomposition. First, we measured tolerance traits and life history traits of soil fauna under standardized laboratory conditions and found that interspecific dissimilarity in functional traits explained shifts in community composition across landscape environmental gradients. Also, species can be aggregated in response groups based on similarity in trait values. Second, experimentally we showed that soil fauna community response to environmental stress could be forecasted from resistance traits and resulted in significant effects on litter decomposition, a key ecosystem process that could be forecasted from species effect traits (specifically litter consumption).
These results suggest that the impact of climate extremes on ecosystems can be predicted from the functional traits and trait linkages of species. These findings contribute to the increasing need to generate empirically tested, mechanistic predictions on the effect of global changes on functionally important organisms and their effect on ecosystem processes.
Contact : Matty P. BERG