A global model of island species–area relationships

Thomas Matthews (1) , François Rigal (2) , Kostas A Triantis (3) , Robert J. Whittaker (4)

1 School of Geography and Environmental Sciences, University of Birmingham
2 IPREM - Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux
3 NKUA - National and Kapodistrian University of Athens
4 University of Oxford

The increase in species richness with island area (ISAR) is a well-established global pattern, commonly described by the power model, the parameters of which are hypothesized to vary with system isolation and to be indicative of ecological process regimes. We tested a structural equation model of ISAR parameter variation as a function of taxon, isolation, and archipelago configuration, using a globally distributed dataset of 151 ISARs encompassing a range of taxa and archipelago types. The resulting models revealed a negative relationship between ISAR intercept and slope as a function of archipelago species richness, in turn shaped by taxon differences and by the amount and disposition of archipelago area. These results suggest that local-scale (intra-archipelago) processes have a substantial role in determining ISAR form, obscuring the diversity patterns predicted by island theory as a function of archipelago isolation. These findings have implications for the use and interpretation of ISARs as a tool within biogeography, ecology, and conservation.

Mots clés: archipelago effects; diversity model; island biogeography; macroecology; species–area relationship

Domaines: Biodiversité et Ecologie

Thomas Matthews, François Rigal, Kostas A Triantis, Robert J. Whittaker. A global model of island species–area relationships. Proceedings of the National Academy of Sciences of the United States of America, 2019, pp.201818190. ⟨10.1073/pnas.1818190116⟩. ⟨hal-02146932⟩