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| Titel |
Soil moisture modifies the response of soil respiration to temperature in a desert shrub ecosystem |
| VerfasserIn |
B. Wang, T. S. Zha, X. Jia, B. Wu, Y. Q. Zhang, S. G. Qin |
| 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. 2 ; Nr. 11, no. 2 (2014-01-22), S.259-268 |
| Datensatznummer |
250117140
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| Publikation (Nr.) |
 copernicus.org/bg-11-259-2014.pdf |
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| Zusammenfassung |
| The current understanding of the responses of soil respiration (Rs) to soil
temperature (Ts) and soil moisture is limited for desert
ecosystems. Soil CO2 efflux from a desert shrub ecosystem was measured
continuously with automated chambers in Ningxia, northwest China, from June
to October 2012. The diurnal responses of Rs to Ts were affected by soil
moisture. The diel variation in Rs was strongly related to Ts at 10 cm depth
under moderate and high volumetric soil water content (VWC), unlike under low
VWC. Ts typically lagged Rs by 3–4 h. However, the lag time varied in
relation to VWC, showing increased lag times under low VWC. Over the seasonal
cycle, daily mean Rs was correlated positively with Ts, if VWC was higher
than 0.08 m3 m−3. Under lower VWC, it
became decoupled from Ts. The annual temperature sensitivity of Rs (Q10)
was 1.5. The short-term sensitivity of Rs to Ts varied significantly over the
seasonal cycle, and correlated negatively with Ts and positively with VWC.
Our results highlight the biological causes of diel hysteresis between Rs and
Ts, and that the response of Rs to soil moisture may result in negative
feedback to climate warming in desert ecosystems. Thus, global carbon cycle
models should account the interactive effects of Ts and VWC on Rs in desert
ecosystems. |
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