| keyword(s) : biodiversité – interactions interspécifiques – interactions non trophiques – fonctionnement des écosystèmes – invasions biologiques – introductions d'espèces – extinctions d'espèces – résistance aux invasions – production – modèle de réseau d'interactions – conservation de la matière |
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Ecosystem functioning and biological invasions :
importance of biodiversity and interspecific interactions |
| Biological invasions are a major threat to native biodiversity and to the ecological services that biodiversity supports. In this study, we construct an assembly interaction web model that includes all types of species interactions (both trophic and non-trophic interactions), and that respects the principle of mass conservation. This model shows a strong effect of non–trophic interactions on ecosystem functional processes (biomass, production) and a diversity-dependence of species interactions, making the mechanisms of the biodiversity - ecosystem functioning relationship more complex in interaction webs than in food webs. The model predicts that species introductions have a strong impact on ecosystem structure and functioning, that resistance to invasion and robustness to resident species extinctions due to invasions increase with species diversity, and are maximal for intermediate prevalence and strength of non-trophic interactions. |
| english keyword(s) : biodiversity – ecosystem functioning – species interactions – non trophic interactions – biological invasions – species introductions – species extinctions – invasion resistance – production – interaction web model – mass conservation |
