spectral optical properties; reflectance; Bílý Kříž; photosynthetic pigments; reflectance indices

Spectral optical properties of leaves indicate their interaction with incident radiation and therefore can be used for non-invasive estimation of plant physiological status. The diurnal course of spectral reflectance, pigment content and selected photosynthetic parameters were examined for 3 different year-class of Norway spruce [Picea abies (L.) Karst.] needles during several sunny days at the Experimental ecological site Bílý Kříž in the Beskydy Mts. (Czech Republic). The applicability of reflectance spectroscopy to examine the diurnal and needle-age dependent variability of pigment content and photosynthetic efficiency was tested. In addition, some improvements of needle spectral reflectance measurement with integrating sphere were introduced. Among the reflectance indices designated to estimate chlorophyll content, some of Chl a+b indices correlated with chlorophylls content whereas no correlations were found with carotenoid content.

Spectral optical properties of leaves indicate their interaction with incident radiation and therefore can be used for non-invasive estimation of plant physiological status. The diurnal course of spectral reflectance, pigment content and selected photosynthetic parameters were examined for 3 different year-class of Norway spruce [Picea abies (L.) Karst.] needles during several sunny days at the Experimental ecological site Bílý Kříž in the Beskydy Mts. (Czech Republic). The applicability of reflectance spectroscopy to examine the diurnal and needle-age dependent variability of pigment content and photosynthetic efficiency was tested. In addition, some improvements of needle spectral reflectance measurement with integrating sphere were introduced. Among the reflectance indices designated to estimate chlorophyll content, some of Chl a+b indices correlated with chlorophylls content whereas no correlations were found with carotenoid content.