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Experimental Tests of the Light-Use Efficiency Model in Alfalfa

  • Author / Creator
    Castro, Saulo M
  • This study explored ways of integrating optical and flux measurements in the context of the Light Use Efficiency (LUE) model in an alfalfa (Medicago sativa) field. Narrow-band spectrometers and low cost two-band radiometers provided alternate ways to measure NDVI and estimate the APAR term of the LUE model. The high temporal resolution of two-band sensors system accurately tracked seasonal carbon flux dynamics (R2 = 0.96) demonstrating the value of automated, low cost approaches to monitoring NDVI and canopy light absorption, which was the dominant term in the LUE model for this agricultural field. At the seasonal scale PRI correlations with LUE varied with the LUE formulation, and suggested that seasonal PRI patterns were primarily driven by canopy structure changes. However, at the diurnal level, ∆PRI correlated with changing efficiency. Combined optical and flux sampling can help partition flux data, gap-fill data, and add insights into the controls of carbon fluxes.

  • Subjects / Keywords
  • Graduation date
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.
  • Language
  • Institution
    University of Alberta
  • Degree level
  • Department
    • Department of Earth and Atmospheric Sciences
  • Supervisor / co-supervisor and their department(s)
    • Gamon, John (Earth and Atmospheric Science)
  • Examining committee members and their departments
    • Flanagan, Lawrence (Biological Sciences, University of Lethbridge)
    • Wolfe, Alexander (Earth and Atmospheric Science)