 |
| Titel |
Major role of marine vegetation on the oceanic carbon cycle |
| VerfasserIn |
C. M. Duarte, J. J. Middelburg, N. Caraco |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 2, no. 1 ; Nr. 2, no. 1 (2005-02-01), S.1-8 |
| Datensatznummer |
250000374
|
| Publikation (Nr.) |
 copernicus.org/bg-2-1-2005.pdf |
|
|
|
|
|
| Zusammenfassung |
| The carbon burial in vegetated sediments, ignored in past assessments of
carbon burial in the ocean, was evaluated using a bottom-up approach derived
from upscaling a compilation of published individual estimates of carbon
burial in vegetated habitats (seagrass meadows, salt marshes and mangrove
forests) to the global level and a top-down approach derived from
considerations of global sediment balance and a compilation of the organic
carbon content of vegeatated sediments. Up-scaling of individual burial
estimates values yielded a total carbon burial in vegetated habitats of
111 Tmol C y-1. The total burial in unvegetated sediments was estimated to
be 126 Tg C y-1, resulting in a bottom-up estimate of total burial in
the ocean of about 244 Tg C y-1, two-fold higher than estimates of
oceanic carbon burial that presently enter global carbon budgets. The
organic carbon concentrations in vegetated marine sediments exceeds by 2 to
10-fold those in shelf/deltaic sediments. Top-down recalculation of ocean
sediment budgets to account for these, previously neglected, organic-rich
sediments, yields a top-down carbon burial estimate of 216 Tg C y-1,
with vegetated coastal habitats contributing about 50%. Even though
vegetated carbon burial contributes about half of the total carbon burial in
the ocean, burial represents a small fraction of the net production of these
ecosystems, estimated at about 3388 Tg C y-1, suggesting that bulk of
the benthic net ecosystem production must support excess respiration in
other compartments, such as unvegetated sediments and the coastal pelagic
compartment. The total excess organic carbon available to be exported to the
ocean is estimated at between 1126 to 3534 Tg C y-1, the bulk of which
must be respired in the open ocean. Widespread loss of vegetated coastal
habitats must have reduced carbon burial in the ocean by about 30 Tg C y-1,
identifying the destruction of these ecosystems as an
important loss of CO2 sink capacity in the biosphere. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|