Influence of freeze-thaw events on carbon dioxide emission from soils at different moisture and land use
Background: The repeated freeze-thaw events during cold season, freezing of soils in autumn and thawing in spring are typical for the tundra, boreal, and temperate soils. The thawing of soils during winter-summer transitions induces the release of decomposable organic carbon and acceleration of soil...
| Published in: | Carbon Balance and Management |
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| Main Authors: | , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
2007
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| Subjects: | |
| Online Access: | https://resolver.sub.uni-goettingen.de/purl?gro-2/60199 https://resolver.sub.uni-goettingen.de/purl?gs-1/4386 https://doi.org/10.1186/1750-0680-2-2 |
| Summary: | Background: The repeated freeze-thaw events during cold season, freezing of soils in autumn and thawing in spring are typical for the tundra, boreal, and temperate soils. The thawing of soils during winter-summer transitions induces the release of decomposable organic carbon and acceleration of soil respiration. The winter-spring fluxes of CO2 from permanently and seasonally frozen soils are essential part of annual carbon budget varying from 5 to 50%. The mechanisms of the freeze-thaw activation are not absolutely clear and need clarifying. We investigated the effect of repeated freezing-thawing events on CO2 emission from intact arable and forest soils (Luvisols, loamy silt; Central Germany) at different moisture (65% and 100% of WHC). Results: Due to the measurement of the CO2 flux in two hours intervals, the dynamics of CO2 emission during freezing-thawing events was described in a detailed way. At +10°C (initial level) in soils investigated, carbon dioxide emission varied between 7.4 to 43.8 mg C m-2h-1 depending on land use and moisture. CO2 flux from the totally frozen soil never reached zero and amounted to 5 to 20% of the initial level, indicating that microbial community was still active at -5°C. Significant burst of CO2 emission (1.21.7-fold increase depending on moisture and land use) was observed during thawing. There was close linear correlation between CO2 emission and soil temperature (R2 = 0.860.97, P < 0.001). |
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