Global gradients in intertidal species richness and functional groups

Whether global latitudinal diversity gradients exist in rocky intertidal ?-diversity and across functional groups remains unknown. Using literature data from 433 sites, we investigated patterns 155° of latitude, whether local-scale or global-scale structuring processes control ?-diversity. We, furthermore, how the relative composition changes with latitude. ?-Diversity differed among hemispheres a mid-latitudinal peak north, non-significant unimodal pattern south, but there was no support for tropical-to-polar decrease Although drivers had discernible effect, significantly affected ?-diversity, our results reveal that are outweighed by local processes. In contrast to patterns, species richness three (predators, grazers, suspension feeders) declined coinciding an inverse gradient algae. Polar tropical were sparse, more sampling is required improve knowledge marine biodiversity.