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Titel |
Carbon losses from pyrolysed and original wood in a forest soil under natural and increased N deposition |
VerfasserIn |
B. Maestrini, S. Abiven, N. Singh, J. Bird, M. S. Torn, M. W. I. Schmidt |
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 ; 11, no. 18 ; Nr. 11, no. 18 (2014-09-29), S.5199-5213 |
Datensatznummer |
250117612
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Publikation (Nr.) |
copernicus.org/bg-11-5199-2014.pdf |
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Zusammenfassung |
Pyrogenic organic matter (PyOM) plays an important role as a stable carbon
(C) sink in the soils of terrestrial ecosystems. However, uncertainties
remain about in situ turnover rates of fire-derived PyOM in soil, the main
processes leading to PyOM-C and nitrogen (N) losses from the soil, and the
role of N availability on PyOM cycling in soils.
We measured PyOM and native soil organic carbon losses from the soil as
carbon dioxide and dissolved organic carbon (DOC) using additions of highly
13C-labelled PyOM (2.03 atom %) and its precursor pinewood during
1 year in a temperate forest soil. The field experiment was
carried out under ambient and increased mineral N deposition (+60 kg
N-NH4NO3 ha−1 year−1). The results showed that after 1 year: (1) 0.5% of PyOM-C and 22% of wood-C were mineralized as
CO2, leading to an estimated turnover time of 191 and 4 years,
respectively; (2) the quantity of PyOM and wood lost as dissolved organic
carbon was negligible (0.0004 ± 0.0003% and 0.022 ± 0.007% of applied-C, respectively); and (3) N additions decreased cumulative
PyOM mineralization by 43%, but did not affect cumulative wood
mineralization and did not affect the loss of DOC from PyOM or wood. We
conclude that mineralization to CO2 was the main process leading to PyOM
losses during the first year of mineralization in a forest soil, and that N
addition can decrease PyOM-C cycling, while added N showed no effect on wood
C cycling. |
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