Microbial
Ecology & Biogeochemistry
The microbial loop
plays a key role in the cycling of
carbon because it is mainly responsible
for respiration in the ocean, putting
in circulation an important amount
of dissolved carbon and it is the only
significant factor in the uptake of
dissolved organic carbon (DOC) produced
by the assemblage of marine organisms.
The amount of respiration determines
the total quantity of biogenic carbon
that is exportable in the ocean and
the uptake of DOC determines the quantity
of DOC that can be exported. There
are three major themes around which
this team is organized, and they are
of major international concern:
- The bottom-up regulation
(by resources) and top-down regulation
(by predators) of microbial populations.
- The contribution
of various microbial groups, particularly
heterotrophic bacteria, to the functioning
of the global pelagic ecosystem.
- Controls on the
microbial loop by external forces
(for example, temperature and the
concentration of phosphorus and pCO2)
and internal forces (for example,
predation, community composition,
and the quality of dissolved organic
matter).
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