Communities’ dynamics and functioning

, par Vidal Ayouba Isabelle

Representatives : David Mouillot (UM2) and Yunne-Jai Shin (IRD)

BACKGROUND

In a context of global change, it is necessary to understand and predict the trajectories of species communities in terms of structure and functioning, to better protect biodiversity and maintain the associated ecological processes.

GOALS

  • To assess the impact of global change (including invasive species and climate change) on the structure (taxonomic, phylogenetic, functional) and functioning of communities.

  • To study the mechanisms which govern the relationships between the structure and functioning of communities of species (complementary niches, biotic interactions such as facilitation, competition and predation).
  • 
To assess the biotic interactions across spatial and temporal scales to integrate them to the models of functioning communities.

  • To identify the thresholds of resilience or regime change of disturbed marine ecosystems.

OBJECTS AND MAIN AREAS OF STUDY

  • Geographic areas : Mediterranean coasts, upwelling ecosystems (Benguela, Humboldt, Canary Islands), phanerogam beds, coral reefs (Indian and Pacific oceans and Vietnam) and mangroves (West Africa, Mayotte, and Vietnam), high sea ocean ecosystems (Indian and Atlantic Oceans).

  • Study models : reef, demersal, small pelagic, and large ocean pelagic communities (interacting with birds and marine mammals).

APPROACHES

  • Data : to sample areas not much impacted by humans in order to define reference levels for all aspects of biodiversity ; To centralize, standardize and facilitate access to spatiotemporal data on species communities from the local to the global scale.

  • Methods : experiments : to handle mesocosm communities to test cause-effect hypotheses on biotic factors (abundance, presence / absence of native and invasive species) and abiotic factors (temperature, organic matter) on the functioning of communities.

  • Analyses and modeling : to statistically link biodiversity to the functioning of large-scale ecosystems to establish a predictive functional biogeography ; to develop hybrid ecosystem models (combining physics, biology, ecology and geochemistry) integrating various biological components (traits, phylogeny, interactions) to better understand and anticipate the trajectory of communities (structure and functioning) ; model the mechanisms related to species invasions, replacements / alternations of species and food chains.


LES PROJETS




MARBEC MARine Biodiversity, Exploitation and Conservation, is a research unit which includes the staff of 4 organizations: IRD, IFREMER, UM and CNRS. Its objective is the study of marine biodiversity in lagoon coastal and offshore ecosystems, at different integration levels, molecular, individual, population and community aspects and the way humans use this biodiversity.