On the multi-temporal correlation between photosynthesis and soil CO2 efflux: reconciling lags and observations.

Journal Article · Sat Jan 01 04:00:00 EST 2011 · New Phytologist

DOI:https://doi.org/10.1111/j.1469-8137.2011.03771.x· OSTI ID:1035145

Vargas, Rodrigo ^[1]; Baldocchi, D. D. ^[2]; Bahn, Michael ^[3]; Hanson, Paul J ^[4]; Hosman, K. P. ^[5]; Kulmala, Liisa ^[6]; Pumpanen, Jukka ^[6]; Yang, Bai ^[4]

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1. Ensenada Center for Scientific Research and Higher Education (CICESE)
2. University of California, Berkeley
3. University of Innsbruck, Austria
4. ORNL
5. University of Missouri
6. University of Helsinki

Although there is increasing evidence of the temporal correlation between photosynthesis and soil CO{sub 2} efflux, no study has so far tested its generality across the growing season at multiple study sites and across several time scales. Here, we used continuous (hourly) data and applied time series analysis (wavelet coherence analysis) to identify temporal correlations and time lags between photosynthesis and soil CO{sub 2} efflux for three forests from different climates and a grassland. Results showed the existence of multi-temporal correlations at time periods that varied between 1 and 16 d during the growing seasons at all study sites. Temporal correlations were strongest at the 1 d time period, with longer time lags for forests relative to the grassland. The multi-temporal correlations were not continuous throughout the growing season, and were weakened when the effect of variations in soil temperature and CO{sub 2} diffusivity on soil CO{sub 2} efflux was taken into account. Multi-temporal correlations between photosynthesis and soil CO{sub 2} efflux exist, and suggest that multiple biophysical drivers (i.e. photosynthesis, soil CO{sub 2} diffusion, temperature) are likely to coexist for the regulation of allocation and transport speed of carbon during a growing season. Future studies should consider the multi-temporal influence of these biophysical drivers to investigate their effect on the transport of carbon through the soil-plant-atmosphere continuum.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1035145
• Journal Information: New Phytologist, Journal Name: New Phytologist Journal Issue: 4 Vol. 191; ISSN 0028-646X; ISSN NEPHAV
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
CARBON
CARBON CYCLE
CLIMATES
DIFFUSION
FORESTS
HYSTERESIS
PHOTOSYNTHESIS
REGULATIONS
RESPIRATION
SEASONS
SOILS
TIME-SERIES ANALYSIS
TRANSPORT
VELOCITY