InterSpe

Species interaction networks : a functional perspective

Animator : Anne LOISON

Biodiversity is globally declining as a result of global changes. When diversity of some taxonomic or functional group decreases, it can affect ecosystem functions and properties (primary productivity, nutrient cycling, resilience to changes) through complex pathways due to interactions among organisms. It is therefore crucial to understand how species are functionally interconnected to envision how modification of the diversity in one component of an ecosystem (e.g. plants) affects diversity of other trophic levels and ecosystem properties.

Our aims here are :

  1. to identify and quantify functional relationships among above- and below- ground groups of organisms connected through trophic and non trophic processes,
  2. estimate how the connectivity and properties of ecological networks affects ecosystem properties.
We will focus more specifically on two networks, the first one being centred on the processes linking herbivores (large herbivores and insects) under the influence of human-related activity and climate change, to plants (diversity, functional traits) and the second on plants, under the influence of management and climate change, on litter and soil properties.

Our three main objectives and associated methods are to :

1. Improve our understanding of the spatio-temporal dynamics of large herbivore communities by identifying species-specific population and individual responses to
  • human lethal and non lethal activities,
  • abiotic drivers (BioGeoChem & ServAlp),
  • food resources characterised in terms of biomass, quality and diversity of plant species and trait values.

Evolutionary consequences of responses of large herbivores to changes in hunting/ disturbance/ landscape will also be studied in relation with DivAdapt.

 

Scale : from community-plot to regional level
Methods : Individual marking, GPS, GIS and geostatistics, Capture-Mark-Recapture, behavioural observation, genetics.
Keywords : long-term individual monitoring, human-wildlife interaction, behavioural syndromes, population and community dynamics, direct and indirect processes, interference and exploitative competition, ecological niche, landscape ecology.

2. Improve our understanding of trophic and non-trophic interaction networks, focusing on small herbivores (insects), large herbivore and plants, and on plants, litter and soils (microorganisms, fungi). This involves identifying direct trophic linkages (e.g. plant-herbivores, plant-decomposers) and indirect linkages (e.g. small to large herbivore, within-herbivores, within plants) that occur through modification of e.g. primary and secondary metabolism in plants (link with ServAlp). We aim at providing inputs to large-scale modelling (BioGeoChem) and to models of ecosystem functions (ServAlp).

 

Scale : ecosystem level in the Alps
Methods : ecological network analysis, DNA-barcoding, exclosure experiments, metagenomics.
Keywords : interaction network, trophic and non-trophic linkage, chemical ecology, metagenomics.

3. Develop models based on functional trait approaches of ecosystems and the mechanistic understanding of ecological networks presented in points (1) and (2) (in connection with BioGeoChem & ServAlp). We aim to provide a better understanding of links between environmental drivers and ecosystem services (as developed in MacroEco), including wild small and large herbivores.

 

Methods : multivariate analyses, trait-based models, ecological network analyses.
Keywords : trophic effect traits, response-effect model.
Study sites : Bauges (human/large-small herbivores/plants/soil), Lautaret (small herbivores-plant-soil).

 

Who is involved ?

Researchers / Professors :

– Arnaud FOULQUIER
– Christiane GALLET
– Laure GALLIEN
– Roberto GEREMIA
– Sébastien IBANEZ
– Anne LOISON
– Tamara MUNKEMULLER
– François PELLISIER
– Wilfried THUILLER
– Glenn YANNIC

Research assistants :

– Maya GUEGUEN
– Annie MILLERY-VIGUES
– Julien RENAUD
– Nathalie TISSOT

Collaborators :

– EDYTEM
– Irstea
– ONCFS
– OSUG
– Tromso University (Norway)
– Zone Atelier Alpes

 

What are the ongoing projects ?

Projects
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