title: Patterns of diversity in marine phytoplankton.
abstract: Spatial diversity gradients are a pervasive feature of life on Earth. We examined a global ocean circulation, biogeochemistry, and ecosystem model that indicated a decrease in phytoplankton diversity with increasing latitude, consistent with observations of many marine and terrestrial taxa. In the modeled subpolar oceans, seasonal variability of the environment led to competitive exclusion of phytoplankton with slower growth rates and lower diversity. The relatively weak seasonality of the stable subtropical and tropical oceans in the global model enabled long exclusion time scales and prolonged coexistence of multiple phytoplankton with comparable fitness. Superimposed on the decline in diversity seen from equator to pole were "hot spots" of enhanced diversity in some regions of energetic ocean circulation, which reflected lateral dispersal.
authors.affiliation: Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA. adbarton@mit.edu
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Barton
authors.forename: Stephanie
authors.initials: S
authors.lastname: Dutkiewicz
authors.forename: Glenn
authors.initials: G
authors.lastname: Flierl
authors.forename: Jason
authors.initials: J
authors.lastname: Bragg
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Follows
mesh_terms: D044822:Biodiversity; D018533:Biomass; D002980:Climate; D017753:Ecosystem; D004777:Environment; D005843:Geography; D008954:Models, Biological; D009792:Oceans and Seas; D010839:Phytoplankton / Q000254:growth & development / Q000502:physiology; D011157:Population Dynamics; D012621:Seasons; D012623:Seawater