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| Titel |
Effects of multiple environmental factors on CO2 emission and CH4 uptake from old-growth forest soils |
| VerfasserIn |
H. J. Fang, G. R. Yu, S. L. Cheng, T. H. Zhu, Y. S. Wang, J. H. Yan, M. Wang, M. Cao, M. Zhou |
| 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 ; 7, no. 1 ; Nr. 7, no. 1 (2010-01-29), S.395-407 |
| Datensatznummer |
250004390
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| Publikation (Nr.) |
 copernicus.org/bg-7-395-2010.pdf |
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| Zusammenfassung |
| To assess contribution of multiple environmental factors
to carbon exchanges between the atmosphere and forest soils, four old-growth
forests referred to as boreal coniferous forest, temperate
needle-broadleaved mixed forest, subtropical evergreen broadleaved forest
and tropical monsoon rain forest were selected along eastern China. In each
old-growth forest, soil CO2 and CH4 fluxes were measured from 2003
to 2005 applying the static opaque chamber and gas chromatography technique.
Soil temperature and moisture at the 10 cm depth were simultaneously
measured with the greenhouse gas measurements. Inorganic N (NH4+-N
and NO3−-N) in the 0–10 cm was determined monthly. From north to
south, annual mean CO2 emission ranged from 18.09 ± 0.22 to
35.40 ± 2.24 Mg CO2 ha−1 yr−1 and annual mean CH4
uptake ranged from 0.04 ± 0.11 to 5.15 ± 0.96 kg CH4 ha−1 yr−1
in the four old-growth forests. Soil CO2 flux in the
old-growth forests was mainly driven by soil temperature, followed by soil
moisture and NO3−-N. Temperature sensitivity (Q10) of soil
CO2 flux was lower at lower latitudes with high temperature and more
precipitation, probably because of less soil organic carbon (SOC). Soil
NO3− accumulation caused by environmental change was often
accompanied by an increase in soil CO2 emission. In addition, soil
CH4 uptake decreased with an increase in soil moisture. The response of
soil CH4 flux to temperature was dependent upon the optimal value of
soil temperature in each forest. Soil NH4+-N consumption tended to
promote soil CH4 uptake in the old-growth forests, whereas soil
NO3−-N accumulation was not conducive to CH4 oxidation in
anaerobic condition. These results indicate that soil mineral N dynamics
largely affects the soil gas fluxes of CO2 and CH4 in the
old-growth forests, along with climate conditions. |
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