INVESTIGATION OF LEAF BIOCHEMISTRY BY STATISTICS

The biochemical concentration (total protein, cellulose, lignin, and s tarch) of 73 plant leaves has been related to their optical properties through statistical relationships. Both fresh and dry plant material, leaves and needles, were used in this study. Stepwise multiple regres sion analyses have been performed on reflectance, transmittance, and a bsorptance values (individual leaves) as well as on reflectance values of optically thick samples (stacked leaves + needles), on measured va lues and on transformations of them such as the first derivative or th e logarithm of the reciprocal of the reflectance. They underscored goo d prediction performances for protein, cellulose, and lignin with high squared multiple correlation coefficients (r(2)) values. Starch, whos e concentration in the leaf was smaller compared to the other componen ts, was estimated with less accuracy. As expected, dry material and op tically thick samples provided respectively stronger correlations than fresh material and individual leaves.