SS2.05 Phylogenetic and Physiologic Successions in Aquatic Bacterial Communities
Date: Monday, June 10, 2002
Time: 10:45:00 AM
Location: Carson C
HagströmÅF, Kalmar University, Kalmar, Sweden,
Bacterioplankton species succession: a matter of proliferation and transport.
The phylogenetic composition of the bacterioplankton community in a given area is governed by species specific rates of growth and mortality. This statement should cause no major debate. Fine, but what mechanism brings the future dominant bacteria to the scene: transport of already adapted organisms from other sea areas, or the proliferation of scarce bacteria residing in the particular water mass? In this presentation the aim is to outline the timeframes of some of the processes that may influence the outcome of succession. Current investigations demonstrating spatial and temporal shifts in bacterioplankton species composition are generally vague when it comes to predicting the factors responsible for the selection. One reason for the lack of arguments may be that as yet there can be found no consensus of the number of niches that might exist for pelagic bacteria. I will argue that in the photic zone of the ocean this number is in the order of 50. As a consequence only a limited number of factors need to be envisioned in order to account for this level of diversity.