Thingstad, T. F. University of Bergen, +47-55589671
Havskum, H. F. Institute for the Water Environment, hha@vki.dk

 
WHY SI SHOULD INTERFERE WITH BACTERIAL ABILITY TO CONSUME GLUCOSE ADDED TO MESOCOSMS.
 
In idealised food web models, the presence of diatoms is subject to two conditions: the availability of silicate, and a growth rate balancing loss by predation. In such a hypothetical world, the simultaneous feeding of limiting nutrients (such as PO4 or NO3), and Si to mesocosms would therefore be expected to induce a diatom bloom, and the extension in time of such a bloom to depend upon the response time of diatom predators. Assuming copepods to be the main predator, the slow predator response will allow a fairly extensive build-up of diatom biomass. As a consequence of Si addition, phytoplankton-bacterial competition for limiting mineral nutrients would thus be shifted away from heterotrophic bacteria. The predicted effect would be a reduction in bacterial ability to degrade added glucose. Results of a simple model formulated in STELLA is compared to experimental results obtained in mesocosms manipulated with NO3, PO4, Si,and glucose.
 
Day: Wednesday, Feb. 3
Time: 11:15 - 11:30am
Location: Hilton of Santa Fe
 
Code: SS38WE1115H