Estimating CO2 exchange at two sites in Arctic tundra ecosystems during the growing season using a spectral vegetation index

Measurements of carbon fluxes in Arctic tundra landscapes are generally obt ained through intensive field work and involve the use of chamber and/or mi crometeorological tower techniques. However, findings in a variety of nonAr ctic ecosystems have demonstrated the potential of remote sensing-based tec hniques (particularly spectral vegetation indices) to provide estimates of CO2 exchange in a more timely and efficient manner. As the first step towar ds modelling Arctic regional and circumpolar fluxes of CO2 using remotely s ensed data, we investigated the relationships between plot-level fluxes of CO2 and a vegetation spectral reflectance index derived from hand-held radi ometric data at two sites. These relationships were evaluated for variation s in vegetation cover type and environmental factors using data collected d uring the short Arctic growing season. Overall, this study demonstrated a r elationship between the Normalized Difference Vegetation Index (NDVI) and m easurements of mean site gross photosynthesis and ecosystem respiration at two sites in Arctic tundra ecosystems on the North Slope of Alaska.