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United States Department of Agriculture

Agricultural Research Service

Research Project: QUANTIFYING AND MONITORING NUTRIENT CYCLING, CARBON DYNAMICS AND SOIL PRODUCTIVITY AT FIELD, WATERSHED AND REGIONAL SCALES

Location: Hydrology and Remote Sensing Laboratory

Title: Canopy level chlorophyll flouresence and PRI in a cornfield

Authors
item Middleton, E
item Cheng, Y
item Corp, L
item Campbell, P
item Huemmrich, K
item Zhang, Q
item Kustas, William

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 31, 2012
Publication Date: July 10, 2012
Citation: Middleton, E.M., Cheng, Y., Corp, L.A., Campbell, P., Huemmrich, K.F., Zhang, Q., Kustas, W.P. 2012. Canopy level chlorophyll flouresence and PRI in a cornfield. 2012 International Geoscience and Remote Sensing Symposium [abstract]. 2012 CDROM.

Technical Abstract: Determining the health and vigor of vegetation using high spectral resolution remote sensing techniques is a critical component in monitoring productivity from both natural and managed ecosystems and their feedbacks to climate. Two spectrally based indices now used in field studies to assess whether vegetation is performing near-optimally or exhibiting symptoms of environmental stress (e.g., drought or nutrient deficiency, non-optimal temperatures, etc.) are the Photochemical Reflectance Index (PRI) and solar-induced red and far-red Chlorophyll Fluorescence (SIF). Both the PRI and SIF express the dynamics of photosynthetic function within green foliage: the PRI is based on reflected radiation in the green spectrum associated with photoprotection via the xanthophyll cycle, whereas SIF measures the absorbed photosynthetically active radiation discarded through emissions, rather than being utilized for photosynthesis. Our previous research demonstrates that the PRI displays directional responses that are strongly expressed and which can be related to the sunlit and shaded canopy fractions. Here, we examine the directional characteristics of red and far-red SIF and their ratio (red/far-red SIF ratio), and compare with those simultaneously acquired for the PRI, in a cornfield at two growth stages in 2010.

Last Modified: 12/21/2014
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