La diversité des traits fonctionnels maximise le fonctionnement des écosystèmes arides

Nicolas Gross
INRA + Dryland Ecology and Global Change Lab, Universidad Rey Juan Carlos, Madrid Nicolas.GROSS@cebc.cnrs.fr

Présentation en français

Functional traits are often invoked to explain species coexistence and ecosystem functioning. However, the hypothesis that trait differences determine the ability of ecosystems to maintain multiple functions simultaneously (multifunctionality) remains largely untested at a global scale. In a survey of 124 dryland plant communities, we found a unique scaling relationship between trait diversity of specific leaf area and maximum plant height and multifunctionality (productivity and surrogates of carbon, nitrogen and phosphorus cycling). Across a variety of species pools and environmental conditions, trait diversity within communities was strikingly high and maximized multifunctionality. Trait diversity had a much stronger impact on multifunctionality than other multifunctionality drivers (e.g. species richness, aridity). We uncovered a general scaling relationship that quantifies how much plant diversity is required to maximize multifunctionality in global drylands.

Recent publications:

Deraison H., Badenhausser I., Loueille N., Scherber C., Gross N. (2015) Functional trait diversity across trophic levels determine herbivores impact on plant community biomass. Ecology Letters, 12, 1346–1355.

Valencia-Gomez E., Maestre T F., Le Bagousse Pinguet Y., Quero, J.L., Tamm R., Borger L., Garcia Gomez M., Gross N. (2015). Functional diversity enhanced resistance of ecosystem multifunctionality to aridity in Mediterranean drylands. New Phytologist, 206, 600-671.

Gross N., Liancourt P., Butters R., Duncan R. Hulme P. (2015) Functional equivalence, competitive hierarchy and facilitation determine species coexistence in highly invaded grasslands. New Phytologist, 206, 175–186.