Variations des propriétés spectrales des feuilles au cours de la croissance du bouleau jaune

Abstract

A yellow birch stand was divided into five age classes (1–5, 6–10, 11–20, 21–40, and >40 years old) to evaluate variations in spectral properties of leaves during the growth of yellow birch. Shade leaves of 1 to 5 year-old seedlings absorb significantly less, while they reflect and transmit significantly more than shade leaves of the other age classes in the 390–725 nm wavelength range. Absorptance differences are more striking in the green and the yellow between 501 and 590 nm (0.067–0.091) than in the orange and the red between 591 and 700 nm (0.041–0.054) and the violet and the blue between 401 and 500 nm (0.017–0.020).