Effects on dispersal in aquatic metacommunities

Using a microcosm experiment with natural phytoplankton assemblages we tested the combined effect of dispersal and disturbance on assemblage composition and productivity. The experimental set-up was designed to simulate conditions typical of natural coastal systems, where periods of isolation are followed by periods of connectivity between local patches. Different levels of disturbance (i.e. different nutrient pulses) formed different assemblages in isolation. With dispersal, the metacommunity homogenized towards the assemblage of the intermediate disturbance, irrespective of the dispersal level. Nitzschiasp, the dominant diatom species under intermediate disturbance maintained productivity at high levels at all dispersal rates. 

Evangelina Smeti