Spatial heterogeneity of planktonic microorganisms in aquatic systems multiscale patterns and processes

Patchiness of planktonic microorganisms may have important implications in microbial communities not only at small scale within habitats but also at large scales within lake basins and districts in landscapes, and within oceanic regions and biogeographical provinces. However, studies are generally limited to one specific planktonic entity (bacterio-, phyto-, or zooplankton) or one spatial scale and extent (across oceans or freshwater systems, or within systems), and there is still no functional perspective on multiscale patchiness patterns of microbial communities and their generative processes. This review presents some of the key aspects of plankton spatial heterogeneity including concepts, patterns, and processes in the context of a multiscale perspective. The ecological significance of spatial heterogeneity for planktonic microorganisms is presented with a functional perspective relating distribution patterns to environmental processes. The importance of abiotic and biotic forces and that of the biophysical coupling in structuring microbial community in aquatic systems at scales relevant to ecological states or processes of organisms, populations, and ecosystems is discussed. The importance of the application of new and advanced technology, as well as statistical approches is presented and their spatial relevance discussed. Keywords: Spatial heterogeneity, microorganisms, plankton communities, marine and freshwater ecosystems.