Dampened copepod-mediated trophic cascades in a microzooplankton-dominated microbial food web: A mesocosm study.

Interactions of bottom-up factors such as the availability of mineral and organic nutrients, and top-down factors like predation and viral infection affect microbial communities of the pelagic food web. Hypothesis derived from previous experimental and modeling work suggest some general mechanisms on how these factors may be linked and call for an experiment to test interactions between (1) nitrogen source and diatom cell size, (2) bacterial growth rate limitation by mineral nutrients versus organic carbon, and (3) enhanced versus decreased predation pressure by copepods ( Calanus finmarchicus). We performed a mesocosm experiment using a replicated three factor--two level full factorial design ( [ABSTRACT FROM AUTHOR]