Vibrational biospectroscopy: what can we say about the surface wax layer of Norway spruce needles?

NIR-excited FT-Raman spectra of the Norway spruce (Picea abies (L.) Karst.) needles were measured by microscopic and macroscopic techniques. From the NIR micro-Raman spectra of the stomatal and interstomatal area, the spectru m of the epistomatal wax was extracted. The effect of the cellular substrat e of the needles on this spectrum is shown and its variability demonstrated by NIR macro-Raman spectra. Strong variability in the spectra of the spruc e needles is observed even for needles of the same age from the same branch . One of the dominant features is variation in intensity of the carotenoid bands. (C) 2001 Elsevier Science B.V. All rights reserved.