MEPS 273:281-289 (2004)  -  doi:10.3354/meps273281

Non-linear dynamics in marine-phytoplankton population systems

Andrea Belgrano1,5,*, Mauricio Lima2, Nils C. Stenseth3,4

1Department of Biology, University of New Mexico, 167 Castetter Hall, Albuquerque, New Mexico 87131-1091, USA
2Center for Advanced Studies in Ecology & Biodiversity, Pontificia Universidad Católica de Chile, PO Box 114-D, Santiago 6513677, Chile
3Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biology, University of Oslo, PO Box 1050 Blindern, 0316 Oslo, Norway
4Institute of Marine Research, Flødevigen Marine Research Station, 4817 His, Norway
5Present address: National Center for Genome Resources (NCGR), 2935 Rodeo Park Drive East, Santa Fe, New Mexico 87505, USA

ABSTRACT: Although non-linear density-dependence has been widely emphasized in population dynamics studies, the existence of non-linear exogenous forces have been less explored. In particular, we propose that the formulation of population dynamics models that include both non-linear endogenous (i.e. feedback structure) and exogenous (e.g. climatic) responses is relevant for understanding how climate variability affects natural systems. Here we show that single-species non-linear logistic models for marine phytoplankton in combination with non-linear exogenous forces capture observed population oscillations very well. Our results suggest that general population dynamic theory represents a useful tool for understanding the natural fluctuations of phytoplankton populations. Altogether we document what might be called a switch-on/switch-off dynamics in the phytoplankton population dynamics in relation to climate variability. We suggest the importance of, and the need for, linking population dynamics processes at local and regional scales to processes at the ecosystem level, thus reflecting a macroecological perspective of marine pelagic systems.

KEY WORDS: Phytoplankton populations · North Atlantic Oscillation · Non-linear dynamics · Density-dependence · Macroecology

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