 |
| Titel |
Mechanisms of microbial carbon sequestration in the ocean – future research directions |
| VerfasserIn |
N. Jiao, C. Robinson, F. Azam, H. Thomas, F. Baltar, H. Dang, N. J. Hardman-Mountford, M. Johnson, D. L. Kirchman, B. P. Koch, L. Legendre, C. Li, J. Liu, T. Luo, Y.-W. Luo, A. Mitra, A. Romanou, K. Tang, X. Wang, C. Zhang, R. Zhang |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 11, no. 19 ; Nr. 11, no. 19 (2014-10-01), S.5285-5306 |
| Datensatznummer |
250117618
|
| Publikation (Nr.) |
 copernicus.org/bg-11-5285-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
This paper reviews progress on understanding biological carbon sequestration
in the ocean with special reference to the microbial formation and
transformation of recalcitrant dissolved organic carbon (RDOC), the
microbial carbon pump (MCP). We propose that RDOC is a concept with a wide
continuum of recalcitrance. Most RDOC compounds maintain their levels of
recalcitrance only in a specific environmental context (RDOCt). The
ocean RDOC pool also contains compounds that may be inaccessible to microbes
due to their extremely low concentration (RDOCc). This differentiation
allows us to appreciate the linkage between microbial source and RDOC
composition on a range of temporal and spatial scales.
Analyses of biomarkers and isotopic records show intensive MCP processes in
the Proterozoic oceans when the MCP could have played a significant role in
regulating climate. Understanding the dynamics of the MCP in conjunction
with the better constrained biological pump (BP) over geological timescales
could help to predict future climate trends. Integration of the MCP and the
BP will require new research approaches and opportunities. Major goals
include understanding the interactions between particulate organic carbon
(POC) and RDOC that contribute to sequestration efficiency, and the
concurrent determination of the chemical composition of organic carbon,
microbial community composition and enzymatic activity. Molecular biomarkers
and isotopic tracers should be employed to link water column processes to
sediment records, as well as to link present-day observations to
paleo-evolution. Ecosystem models need to be developed based on empirical
relationships derived from bioassay experiments and field investigations in
order to predict the dynamics of carbon cycling along the stability
continuum of POC and RDOC under potential global change scenarios. We
propose that inorganic nutrient input to coastal waters may reduce the
capacity for carbon sequestration as RDOC. The nutrient regime enabling
maximum carbon storage from combined POC flux and RDOC formation should
therefore be sought. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|