Skip to main content
ARS Home » Plains Area » Mandan, North Dakota » Northern Great Plains Research Laboratory » Research » Publications at this Location » Publication #144591
Title: CARBON DIOXIDE FLUX OVER A GRAZED MIXED-GRASS PRAIRIE.

Author
item Frank, Albert

Submitted to: International Rangeland Congress
Publication Type: Proceedings
Publication Acceptance Date: 1/8/2003
Publication Date: 7/26/2003
Citation: FRANK, A.B. CARBON DIOXIDE FLUX OVER A GRAZED MIXED-GRASS PRAIRIE. In: Allsopp, N., A.R. Palmer, S.J. Milton, K.P. Kirkman, G.I.H. Kerley, C.R. Hurt, and C.J. Brown (Eds.). Proceedings of the VII INTERNATIONAL RANGELAND CONGRESS, July 26-August 1, 2003, Durban, South Africa. Document Transformation Technologies. 2003. p. 1077-1079.

Interpretive Summary: Grasslands contain nearly 80 percent of their biomass below ground, which serves as storage for carbon from atmospheric carbon dioxide. Since agriculture is increasingly taking on the role of mitigating carbon dioxide emissions into the atmosphere the large area occupied by grasslands makes it important to determine their role in sequestering atmospheric carbon. The Bowen ratio/energy balance technique was used to measure carbon dioxide fluxes over a moderately grazed mixed-grass prairie at Mandan, ND from 1995 to 2001. Net carbon sequestration ranged from 4 to 67 g CO2-C m-2 yr-1. The cumulative flux over the seven years totaled 240 g CO2-C m-2 or about 34 g CO2-C m-2 yr-1. These results from a long-term seven year study quantify the carbon storage potential for this grazed prairie site to be quite small, but considering that the site was grazed and still remains a sink for atmospheric carbon dioxide is significant.

Technical Abstract: Temperate grassland ecosystems occupy vast areas worldwide that are important in the global carbon cycle, but annual CO2 flux data for these grasslands are limited. The CO2 Bowen ratio/energy balance technique was used to measure CO2 fluxes over a moderately grazed mixed-grass prairie site during 1995, 1996, 1997, 1998, 1999, 2000 and 2001 at Mandan, ND. The site is mostly cool season grass species with a complement of warm season grasses. Annual precipitation averages 404 mm. The net annual CO2 fluxes over the seven years from 1995 through 2001 ranged from 4 to 67 g CO2-C m-2 yr-1. The cumulative flux for the seven years totaled 240 g CO2-C m-2 or about 34 g CO2-C m-2 yr-1. Growing period fluxes ranged from 73 g CO2-C m-2 in 1996 to 154 g CO2-C m-2 in 1995. The cumulative growing period flux over the seven year period was 770 g CO2-C m-2 for an annual growing period flux of 110 g CO2-C m-2 yr-1. Average dormant period CO2 losses were 69% of the net growing period CO2 flux. These results quantify the strength of the carbon sink for this grazed prairie site to be quite small, but considering that the site was grazed and still remains a sink for carbon is significant.