Mick Follows, MIT
A numerical model of global ocean circulation, biogeochemistry and ecosystem reveals large scale patterns in the diversity of phytoplankton. There is a decline in "species richness" from equator to pole, as observed in many ecosystems, and the highest diversity occurs in regions of energetic circulation. Using simple models we infer that the meridional gradient is related to the polewards increase in seasonality and that the high diversity regions are due to rapid transport and immigration. The model suggests testable hypotheses and strategies for further field studies.