© 1995 Heron Publishing—Victoria, Canada
Exploring the relationship between reflectance red edge and chlorophyll concentration in slash pine leaves
Paul J. Curran (1), W. Robert Windham (2) and Henry L. Gholz (3)
1. Department of Geography, University of Southampton, Highfield, Southampton SO17 1BJ, U.K. / 2. Richard B. Russell Agricultural Research Center, United States Department of Agriculture, P.O. Box 5677, Athens, GA 30613,
USA / 3. Department of Forestry, University of Florida, Gainesville, FL 32611, USA / Received June 30, 1993
Summary
Chlorophyll concentration is related positively to the point of maximum slope in the reflectance spectra of leaves and this
point is termed the red edge. The reflectance spectra of slash pine (Pinus elliottii Engelm.) needles were measured in the field and the chlorophyll concentrations of the same needles were measured in the laboratory.
The measurement errors for red edge and chlorophyll concentration were determined to be 2.2 nm (3% of mean) and 0.35 mg g–1 (19% of mean), respectively. The red edge–chlorophyll concentration relationship was strong (r2 = 0.82, n = 152). A red edge–chlorophyll concentration relationship for n = 100 was used with red edge measurements to estimate chlorophyll concentration with an rms error of 0.31 mg g–1 (17% of mean, n = 52). The entire red edge–chlorophyll concentration relationship for n = 152 was also used with red edge measurements to estimate the chlorophyll concentration of samples from an earlier experiment
with an rms error of 0.47 mg g–1 (30% of mean, n = 38). We conclude that measures of red edge can be used to estimate the chlorophyll concentration of detached needles in
the field with an accuracy similar to that obtained by conventional laboratory measurements.
Keywords:
Pinus elliottii, reflectance spectroscopy.
