Geographical partitioning of marine macrophyte assemblages in the tropical Pacific: a result of local and regional diversity processes

摘要: Aim Various coral reef organisms display distinct gradients in taxonomic turnover throughout the tropical Pacific Ocean. Marine macrophytes are one of most dominant and ecologically important benthic components reefs, yet little is known about ecological biogeography macrophyte assemblages this biodiverse region. This study assessed: (1) geographical clustering Pacific; (2) environmental/geographical factors that best explain observed patterns taxon richness composition; (3) validity large-scale biogeographical hypotheses with respect to distribution assemblages. Location Coral reefs 39 US islands. Methods Surveys for all islands were conducted from 2004 2007. Rank-order data quadrats transformed proportional abundance order compute site averages each 84 categories. Further analysis employed accumulation curves, generalized additive models, multivariate techniques. Results Pacific displayed consistently higher within-archipelago similarities than between-archipelago similarities, which reflected pronounced differences functional group composition between archipelagos. The maximum land elevation, seasonal sea surface temperature, extent, longitude investigated predictor variables described assemblage structure among islands. Maximum elevation however, two explained per island. Main conclusions Macrophyte Islands cluster groups, indicative importance evolutionary related dispersal speciation. Whereas governed by both local (habitat diversity availability) regional (geographical environmental descriptors oceanic isolation latitude) variables, these defined primarily habitat availability. Biogeographical marine deviate those other well-studied organisms.