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| Titel |
Transient simulations of the carbon and nitrogen dynamics in northern peatlands: from the Last Glacial Maximum to the 21st century |
| VerfasserIn |
R. Spahni, F. Joos, B. D. Stocker, M. Steinacher, Z. C. Yu |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 9, no. 3 ; Nr. 9, no. 3 (2013-06-20), S.1287-1308 |
| Datensatznummer |
250018067
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| Publikation (Nr.) |
 copernicus.org/cp-9-1287-2013.pdf |
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| Zusammenfassung |
| The development of northern high-latitude peatlands played an important role
in the carbon (C) balance of the land biosphere since the Last Glacial
Maximum (LGM). At present, carbon storage in northern peatlands is
substantial and estimated to be 500 ± 100 Pg C
(1 Pg C = 1015 g C). Here, we develop and apply a peatland module
embedded in a dynamic global vegetation and land surface process model
(LPX-Bern 1.0). The peatland module features a dynamic nitrogen cycle, a
dynamic C transfer between peatland acrotelm (upper oxic layer) and catotelm
(deep anoxic layer), hydrology- and temperature-dependent respiration rates,
and peatland specific plant functional types. Nitrogen limitation
down-regulates average modern net primary productivity over peatlands by
about half. Decadal acrotelm-to-catotelm C fluxes vary between −20 and
+50 g C m−2 yr−1 over the Holocene. Key model parameters are
calibrated with reconstructed peat accumulation rates from peat-core data.
The model reproduces the major features of the peat core data and of the
observation-based modern circumpolar soil carbon distribution. Results from a
set of simulations for possible evolutions of northern peat development and
areal extent show that soil C stocks in modern peatlands increased by
365–550 Pg C since the LGM, of which 175–272 Pg C accumulated between
11 and 5 kyr BP. Furthermore, our simulations suggest a persistent C
sequestration rate of 35–50 Pg C per 1000 yr in present-day peatlands
under current climate conditions, and that this C sink could either sustain
or turn towards a source by 2100 AD depending on climate trajectories as
projected for different representative greenhouse gas concentration pathways. |
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