Estimation of Carbon Sequestration by Combining Remote Sensing and Net Ecosystem Exchange Data for Northern Mixed-Grass Prairie and Sagebrush–Steppe Ecosystems

Authors

E. Raymond Hunt Jr., USDA-ARS, Beltaville, Maryland
Robert D. Kelly, University of Wyoming
William K. Smith, Wake Forest UniversityFollow
Jace T. Fahnestock, Colorado State University - Fort Collins
Jeffrey M. Welker, Colorado State University - Fort Collins
William A. Reiners, University of Wyoming

Document Type

Article

Date of this Version

1-14-2004

Comments

Environmental Management Vol. 33, Supplement 1, pp. S432–S441 © 2004 Springer-Verlag New York, LLC

Abstract

Carbon sequestration was estimated a northern mixed-grass prairie site and a sagebrush–steppe site in southeastern Wyoming using an approach that integrates remote sensing, CO₂ flux measurements, and meteorological data. Net ecosystem exchange (NEE) of CO₂ was measured using aircraft and ground flux techniques and was linearly related to absorbed photosynthetically active radiation (APAR). The slope of this relationship is the radiation use efficiency (ε = 0.51 g C/MJ APAR); there were no significant differences in the regression coefficients between the two sites. Furthermore, ecosystem chamber measurements of total respiration in 1998 and 1999 were used to develop a functional relationship with daily average temperature; the Q₁₀ of the relationship was 2.2. Using the Advanced Very High Resolution radiometer. Normalized Difference Vegetation Index and meteorological data, annual gross primary production and respiration were calculated from 1995 to 1999 for the two sites. Overall, the sagebrush– steppe site was a net carbon sink, whereas the northern mixed-grass prairie site was in carbon balance. There was no significant relationship between NEE and APAR for a coniferous forest site, indicating this method for scaling up CO₂ flux data may be only applicable to rangeland ecosystems. The combination of remote sensing with data from CO₂ flux networks can be used to estimate carbon sequestration regionally in rangeland ecosystems.