a marine ecosystem model with self-assembling community structure

We developed a marine ecosystem model that when  initialized with many phytoplankton types whose physiological traits were determined stochastically, community structure and biogeography emerged to be consistent with known distributions of microbes in the global oceans.  This approach to ecosystem modeling, can contribute to the understanding of marine microbial ecology, interfacing naturally with rapidly expanding microbial databases and genomic information.  The flexible representation of the ecosystem model is also particularly suitable for studies of the relationship between ecosystem community structure, biogeochemical cycles and climate change.  Our first study with the model was able to capture simultaneous consistency between the geographical habitat, rank abundance, and physiological specialization of the emergent cyanobacteria Prochlorococcus model ecotypes and their real-world counterparts.

Figure caption: Observed and modeled properties along the AMT13 cruise track. Left column shows observations (Johnson et al, Science, 311, 918, 2006), right column shows results from a single model integration. (A,B) Nitrate (µmol kg–1); (C,D) total Prochlorococcus abundance [log (cells ml–1)]. (E,G,I,K) Distributions of the four most abundant Prochlorococcus ecotypes [log (cells ml–1)] ranked vertically. (F,H,J) The three emergent model ecotypes ranked vertically by abundance. Model Prochlorococcus biomass was converted to cell density assuming a quota of 1 fg P cell–1. Black lines indicate isotherms. (From Follows et al. 2007)

For more information

  • Follows, M.J., S. Dutkiewicz, S. Grant and S.W. Chisholm, 2007: Emergent biogeography of microbial communities in a model ocean. Science, 315, 1843-1846, DOI: 10.1126/science.1138544. Read (subscription required).