ARS | Publication request: Spectral measurements of photosynthetic efficiency

Submitted to: International Symposium on Recent Advances in Quantitative Remote Sensing
Publication Type: Proceedings
Publication Acceptance Date: December 20, 2010
Publication Date: May 5, 2011
Citation: Middleton, E.M., Yen-Ben, C., Huemmrich, K.F., Zhang, Q., Campbell, P.K., Corp, L.A., Kustas, W.P., Margolis, H.A. 2011. Spectral measurements of photosynthetic efficiency. In: Proceedings of the International Symposium on Recent Advances in Quantitative Remote Sensing, September 27-October 1, 2010, Torrent, Spain. p. 845-850.

Technical Abstract: The photosynthetic efficiency of plants was examined for plants in two very different canopies, a USDA cornfield having an instrumented flux tower in Beltsville, MD, USA and a coniferous forest in British Columbia, Canada, included in the tower network of the Canadian Carbon Program. Basic field studies were conducted at both sites with high spectral resolution radiometers to determine spectral indices that were well-correlated to leaf and canopy-level photosynthetic light use efficiency (LUE). LUE is the ratio of gross primary production (GPP) and the photosynthetically active radiation absorbed by the canopy (APAR), or GPP/APAR. We focus here on the Photosynthetic Reflectance Index (PRI), a normalized difference index that uses two narrow green spectral bands. We present diurnal, seasonal, and directional results for the PRI in both vegetated systems.