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| Titel |
Northern peatland carbon stocks and dynamics: a review |
| VerfasserIn |
Z. C. Yu |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 9, no. 10 ; Nr. 9, no. 10 (2012-10-22), S.4071-4085 |
| Datensatznummer |
250007339
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| Publikation (Nr.) |
 copernicus.org/bg-9-4071-2012.pdf |
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| Zusammenfassung |
Peatlands contain a large belowground carbon (C) stock in the biosphere, and
their dynamics have important implications for the global carbon cycle.
However, there are still large uncertainties in C stock estimates and poor
understanding of C dynamics across timescales. Here I review different
approaches and associated uncertainties of C stock estimates in the
literature, and on the basis of the literature review my best estimate of C
stocks and uncertainty is 500 ± 100 (approximate range) gigatons of C
(Gt C) in northern peatlands. The greatest source of uncertainty for all the
approaches is the lack or insufficient representation of data, including
depth, bulk density and carbon accumulation data, especially from the
world's large peatlands. Several ways to improve estimates of peat carbon
stocks are also discussed in this paper, including the estimates of C
stocks by regions and further utilizations of widely available basal peat
ages.
Changes in peatland carbon stocks over time, estimated using
Sphagnum (peat moss) spore data and down-core peat accumulation
records, show different patterns during the Holocene, and I argue that
spore-based approach underestimates the abundance of peatlands in their early
histories. Considering long-term peat decomposition using peat accumulation
data allows estimates of net carbon sequestration rates by peatlands, or net
(ecosystem) carbon balance (NECB), which indicates more than half of peat
carbon (> 270 Gt C) was sequestrated before 7000 yr ago during the
Holocene. Contemporary carbon flux studies at 5 peatland sites show much
larger NECB during the last decade (32 ± 7.8 (S.E.) g C m−2 yr–1) than during the last 7000 yr (∼
11 g C m−2 yr–1), as modeled from peat records across
northern peatlands. This discrepancy highlights the urgent need for carbon
accumulation data and process understanding, especially at decadal and
centennial timescales, that would bridge current knowledge gaps and
facilitate comparisons of NECB across all timescales. |
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