Biodiversity in metacommunities: Plankton as complex adaptive systems?

One of the more intriguing and challenging developments in ecology and in limnology and oceanography is the expansion of the temporal and spatial scales that are being addressed by current work. Researchers are realizing that individual communities and ecosystems are not isolated from each other but rather that they are connected by exchanges of individuals (through dispersal) and materials (through spatial fluxes). From a conceptual perspective, there is a need to develop theories and hypotheses about the roles of these exchanges on different community and ecosystem attributes. Here we focus on the concept of metacommunities, to address how plankton communities are structured and how this may generate patterns of variation in planktonic ecosystems. Our premise is that planktonic systems can be understood in the framework of metacommunities and that the regulation of these metacommunities alter how they work as ‘‘complex adaptive systems.’’ We hypothesize that connectivity through dispersal of local communities that are embedded in aquatic metacommunities show a range of dynamic behaviors related to their capacity to respond adaptively to environmental change. Much work in limnetic ecosystems has shown the rich array of community and ecosystem processes that regulate ponds, lakes, and larger bodies of water such as large lakes, seas, and oceans. This work has shown that limnetic ecosystems as a whole respond strongly to joint effects of abiotic resources (bottom-up effects) and of factors affecting