Modeling the effects of soil thermal dynamics on the seasonality of carbon fluxes across northern temperate and high latitude regions

Conference Proceedings Paper
Modeling the effects of soil thermal dynamics on the seasonality of carbon fluxes across northern temperate and high latitude regions
Zhuang, Q., J.S. Clein, A.D. McGuire, J. Melillo, R.J. Dargaville, D.W. Kicklighter and J.E. Hobbie (2002)
Conference Proceedings, Ecological Society of America 87th Mtg.

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Abstract/Summary:

Understanding the role of soil thermal dynamics on the seasonality of carbon fluxes of ecosystems is critical in clarifying the potential of ecosystems to act as a net source or sink of carbon in the future. The Terrestrial Ecosystem Model (TEM) was coupled to a soil thermal model (STM) and parameterized with observed soil thermal data for sites of the Long Term Ecological Research network in the United States. In addition to the influences of the soil thermal regime on below-ground ecosystem processes, the physical process of freeze/thaw simulated by the STM-TEM also influences the length of growing season. In this study, the STM-TEM was applied to simulate terrestrial carbon dynamics at the global scale from 1859 to 1995. The seasonal dynamics of net primary production (NPP), heterotrophic respiration (RH), and net ecosystem production (NEP, i.e., NPP - RH) for the region between latitudes 60o to 90o N were compared with NPP, RH, and NEP simulated by previous versions of TEM. Simulated NPP by the STM-TEM was similar to that simulated by TEM from January to March and from October to December, was lower from April to May, and higher from July to September; peak NPP was shifted from June to July. Simulated RH by the STM-TEM was similar to TEM but more dynamic from January to April, higher in May, June, September, and October, and lower in July and August. Simulated NEP by the STM-TEM was similar to TEM from November to April, lower in May and June, higher from July to September, and lower in October. The seasonal patterns of NEP simulated by the STM-TEM are similar to the seasonal patterns of net ecosystem exchange estimated from eddy covariance studies of high latitude ecosystems. The next step is to couple the carbon fluxes simulated by the STM-TEM with the Model of Atmospheric Transport and Chemistry (MATCH) and to compare the dynamics of simulated and observed CO2 concentrations at global monitoring stations to further evaluate the effects of soil thermal dynamics on carbon fluxes at regional and global scales.

Citation:

Zhuang, Q., J.S. Clein, A.D. McGuire, J. Melillo, R.J. Dargaville, D.W. Kicklighter and J.E. Hobbie (2002): Modeling the effects of soil thermal dynamics on the seasonality of carbon fluxes across northern temperate and high latitude regions. Conference Proceedings, Ecological Society of America 87th Mtg. (http://www.esa.org/meetings/pastmeetings.php)
  • Conference Proceedings Paper
Modeling the effects of soil thermal dynamics on the seasonality of carbon fluxes across northern temperate and high latitude regions

Zhuang, Q., J.S. Clein, A.D. McGuire, J. Melillo, R.J. Dargaville, D.W. Kicklighter and J.E. Hobbie

Conference Proceedings
Ecological Society of America 87th Mtg.

Abstract/Summary: 

Understanding the role of soil thermal dynamics on the seasonality of carbon fluxes of ecosystems is critical in clarifying the potential of ecosystems to act as a net source or sink of carbon in the future. The Terrestrial Ecosystem Model (TEM) was coupled to a soil thermal model (STM) and parameterized with observed soil thermal data for sites of the Long Term Ecological Research network in the United States. In addition to the influences of the soil thermal regime on below-ground ecosystem processes, the physical process of freeze/thaw simulated by the STM-TEM also influences the length of growing season. In this study, the STM-TEM was applied to simulate terrestrial carbon dynamics at the global scale from 1859 to 1995. The seasonal dynamics of net primary production (NPP), heterotrophic respiration (RH), and net ecosystem production (NEP, i.e., NPP - RH) for the region between latitudes 60o to 90o N were compared with NPP, RH, and NEP simulated by previous versions of TEM. Simulated NPP by the STM-TEM was similar to that simulated by TEM from January to March and from October to December, was lower from April to May, and higher from July to September; peak NPP was shifted from June to July. Simulated RH by the STM-TEM was similar to TEM but more dynamic from January to April, higher in May, June, September, and October, and lower in July and August. Simulated NEP by the STM-TEM was similar to TEM from November to April, lower in May and June, higher from July to September, and lower in October. The seasonal patterns of NEP simulated by the STM-TEM are similar to the seasonal patterns of net ecosystem exchange estimated from eddy covariance studies of high latitude ecosystems. The next step is to couple the carbon fluxes simulated by the STM-TEM with the Model of Atmospheric Transport and Chemistry (MATCH) and to compare the dynamics of simulated and observed CO2 concentrations at global monitoring stations to further evaluate the effects of soil thermal dynamics on carbon fluxes at regional and global scales.

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