Bacterial community composition responds to changes in copepod abundance and alters ecosystem function in an Arctic mesocosm study.

ABSTRACT: Combining a minimum food web model with Arctic microbial community dynamics, we have suggested that top-down control by copepods can affect the food web down to bacterial consumption of organic carbon. Pursuing this hypothesis further, we used the minimum model to design and analyse a mesocosm experiment, studying the effect of high (+Z) and low (-Z) copepod density on resource allocation, along an organic-C addition gradient. In the Arctic, both effects are plausible due to changes in advection patterns (affecting copepods) and meltwater inputs (affecting carbon). The model predicts a trophic cascade from copepods via ciliates to flagellates, which was confirmed experimentally. Auto- and heterotrophic flagellates affect bacterial growth rate and abundance via competition for mineral nutri

SUBMITTER: Tsagaraki TM 

PROVIDER: S-EPMC6194086 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature