Ecological networks and species interactions

The species in a given habitat interact with each other in very different ways; such interactions can vary from the consumption of one organism by another (herbivory, predation, parasitism) to mutualistic relationships (pollination, seed dispersal). These interactions form networks which can prove to be quite complex and even encompass indirect interactions - for instance those that occur when two species compete for the same resource, or when a species indirectly favors another by consuming one of its predators. Analyzing the structure of these interactions is essential for understanding population dynamics and ecosystem function. 

In the current context of biodiversity loss, it is important to keep in mind that some interactions may disappear before the species involved are removed from the ecosystem. It is CREAF's mission to analyze the structure and the robustness of interaction networks as they face different pressures of global change (climate change, land use change, agricultural intensification, biological invasions). We study the effects of these factors on different trophic networks (soil organisms, mountain ecosystems, lacustrine systems) and relationships (seed dispersal, pollination), as well as implications for ecosystem function (biogeochemical cycles, forest growth, production of fruits and seeds).

The main lines of work and experience of CREAF in this field include:

• Biogeochemical cycles: We study the relationships between biotic interactions and biogeochemical cycles. 
• Volatile organic compounds: We evaluate the importance of plants' volatile organic compounds in interactions with other plants, microorganisms, and animals.
• Soil microarthropods: We analyze the temporal and spatial variations of soil microarthropods' trophic interactions. 
• Insects and fungi:  We measure the trophic interactions between insects and fungi using metabarcoding techniques.
• Mountain ecosystem ecological networks and invasive species: We evaluate the resistance of mountain ecosystem ecological networks to invasive species. 
• Plant-pollinator networks: We study the biological attributes determining the structure of plant-pollinator networks.
• Host-parasite: We monitor the spatial and temporal variability of host-parasite networks.
• Pollination: Relationship between the structure of plant-pollinator networks and the ecosystem function of pollination.
• Lacustrine ecosystems: We study changes in the structure and dynamics of trophic networks in remote lake ecosystems as sentinel systems to long-distance pollution and climate change.
• Soil trophic networks: We study the biodiversity and ecosystem functions of soil trophic networks. 
• Exotic plants and herbivores: We evaluate the morphological and chemical functional traits that determine the success of exotic plant species and their interactions with herbivores.
• Vegetation and soil microbial communities: We study the interaction between vegetation and soil microbial communities.
• Competition and facilitation: We study plant competition and facilitation relationships.