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United States Department of Agriculture

Agricultural Research Service

Title: Elevated Atmospheric Co2 Increases Soil Respiration in a Model Regenerating Longleaf Pine Ecosystem

Authors
item Runion, George
item Butnor, J - USDA FOREST SERVICE
item Prior, Stephen
item Mitchell, R - JONES ECOL.RES.CTR.
item Pritchard, S - BELMONT UNIVERSITY
item Davis, M - UNIV. OF SO. MISS.
item Rogers Jr, Hugo
item Johnsen, K - USDA FOREST SERVICE

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: November 19, 2002
Publication Date: November 19, 2002
Citation: Runion, G.B., Butnor, J.R., Prior, S.A., Mitchell, R.J., Pritchard, S.G., Davis, M.A., Rogers, H.H., and Johnsen, K.H. 2002. Elevated atmospheric CO2 increases soil respiration in a model regenerating longleaf pine ecosystem. 4th Longleaf Alliance Regional Conference: Longleaf Pine: A Southern Legacy Rising from the Ashes, Program and Abstracts. Pinehurst, NC, Nov. 17-20.

Technical Abstract: Elevated atmospheric CO2 can affect both the quantity and quality of plant tissues, which will impact the cycling and storage of carbon (C) within plant/soil systems and the rate of CO2 release back to the atmosphere; research is needed to more accurately quantify the effects of CO2 on soil respiration in order to predict the potential of terrestrial ecosystems to sequester C. We investigated the effects of ambient and twice ambient levels of atmospheric CO2 on soil respiration in a model regenerating longleaf pine community using a novel, continuous, soil CO2 efflux monitoring system. A significant increase (26.5 %) in soil CO2 efflux, across a 90 day measurement period, was observed for plant communities exposed to elevated CO2; this effect was significant for all weekly and daily average respiration rates during this period with the exception of the two days when soil temperatures were lowest. Soil CO2 efflux showed a strong positive relationship with soil temperature and a possible increase in the response of soil respiration to temperature under elevated CO2. Soil CO2 efflux showed a strong negative relationship with soil moisture; however, CO2 efflux was not strongly correlated with root biomass. Our data indicate that, while increasing levels of CO2 will increase the feedback of CO2 to the atmosphere via soil respiration, terrestrial ecosystems remain potential sinks for atmospheric CO2.

Last Modified: 8/1/2014
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