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| Titel |
Effects of soil rewetting and thawing on soil gas fluxes: a review of current literature and suggestions for future research |
| VerfasserIn |
D.-G. Kim, R. Vargas, B. Bond-Lamberty, M. R. Turetsky |
| 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. 7 ; Nr. 9, no. 7 (2012-07-09), S.2459-2483 |
| Datensatznummer |
250007180
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| Publikation (Nr.) |
 copernicus.org/bg-9-2459-2012.pdf |
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| Zusammenfassung |
| The rewetting of dry soils and the thawing of frozen soils are short-term,
transitional phenomena in terms of hydrology and the thermodynamics of soil
systems. The impact of these short-term phenomena on larger scale ecosystem
fluxes is increasingly recognized, and a growing number of studies show that
these events affect fluxes of soil gases such as carbon dioxide (CO2),
methane (CH4), nitrous oxide (N2O), ammonia (NH3) and nitric
oxide (NO). Global climate models predict that future climatic change is
likely to alter the frequency and intensity of drying-rewetting events and
thawing of frozen soils. These future scenarios highlight the importance of
understanding how rewetting and thawing will influence dynamics of these
soil gases. This study summarizes findings using a new database containing
338 studies conducted from 1956 to 2011, and highlights open research
questions. The database revealed conflicting results following rewetting and
thawing in various terrestrial ecosystems and among soil gases, ranging from
large increases in fluxes to non-significant changes. Studies reporting
lower gas fluxes before rewetting tended to find higher post-rewetting
fluxes for CO2, N2O and NO; in addition, increases in N2O
flux following thawing were greater in warmer climate regions. We discuss
possible mechanisms and controls that regulate flux responses, and recommend
that a high temporal resolution of flux measurements is critical to capture
rapid changes in gas fluxes after these soil perturbations. Finally, we
propose that future studies should investigate the interactions between
biological (i.e., microbial community and gas production) and physical
(i.e., porosity, diffusivity, dissolution) changes in soil gas fluxes, apply
techniques to capture rapid changes (i.e., automated measurements), and
explore synergistic experimental and modelling approaches. |
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