EFFECTS OF GLOBAL CHANGE ON THE TROPHIC META-NETWORKS OF SMALL ISLANDS (ISLET-FOODWEBS)

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Abstract: Despite their much lower land extension compared to continental areas, islands harbor much of the world’s threatened biodiversity, mostly due to habitat degradation and loss, exploitation of natural resources and the introduction of alien invasive species. Understanding how island communities are assembled and function may help preventing the loss of such valuable biodiversity which consists not only of species but also of the interactions between them. In this project, we study the network structure (including both mutualistic and antagonistic interactions) of islets from five archipelagos (two in the tropics and three in the temperate zone), with the aim of identifying (by means of co-extinction models) the tipping point beyond which ecosystem functioning can collapse due to a disturbance, such as the loss of a keystone species. The reconstruction of the natural history of each islet community and the knowledge on its functioning will allow to foresee the fragility of the islets’ ecosystems to different types of disturbances and will thus be useful to environmental managers to elaborate better strategies for their conservation.