Combining α - and β -diversity models to fill gaps in our knowledge of biodiversity

For many taxonomic groups, sparse information on the spatial distribution of biodiversity limits our capacity toanswer a variety of theoretical and applied ecological questions. Modelling community-level attributes (a- andb-diversity) over space can help overcome this shortfall in our knowledge, yet individually, predictions of a-or b-diversity have their limitations. In this study, we present a novel approach to combining models of a- andb-diversity, with sparse survey data, to predict the community composition for all sites in a region. We appliedour new approach to predict land snail community composition across New Zealand. As we demonstrate, thesepredictions of metacommunity composition have diverse potential applications, including predicting c-diversityfor any set of sites, identifying target areas for conservation reserves, locating priority areas for future ecologicalsurveys, generating realistic compositional data for metacommunity models and simultaneously predicting thedistribution of all species in a taxon consistent with known community diversity patterns.KeywordsAlpha, beta, community, dissimilarity, diversity, gamma, metacommunity, macroecology, richness, snail.Ecology Letters (2011) 14: 1043–1051