Ecological specialization of mixotrophic plankton in a mixed water column
Troost, T. A., Kooi, B. W. and Kooijman, S. A. L. M. 2005
Ecological specialization of mixotrophic plankton in a mixed water column.
Am. Nat, 166: E45 - E61
Abstract
In recent years, the population dynamics of plankton in light- or
nutrient-limited environments have been studied extensively. Their
evolutionary dynamics, however, have received much less
attention. Here, we used a modeling approach to study the evolutionary
behavior of a population of plankton living in a mixed water
column. Initially, the organisms are mixotrophic and thus have both
autotrophic and heterotrophic abilities. Through evolution of their
trophic preferences, however, they can specialize into separate
autotrophs and heterotrophs. It was found that the light intensity
gradient enables evolutionary branching and thus may result in the
ecological specialization of the mixotrophs. By affecting the
gradient, other environmental properties also acquire influence on
this evolutionary process. Intermediate mixing intensities, large
mixing depths, and high nutrient densities were found to facilitate
evolutionary branching and thus specialization. Later results may
explain why mixotrophs are often more dominant in oligotrophic systems
while specialist strategies are associated with eutrophic systems.