Chlorophyll fluorescence decay profiles of O3-exposed spruce needles as measured by time-correlated single photon counting.

Evans, E. H. and Brown, R. G. and Wellburn, A. R. (1992) Chlorophyll fluorescence decay profiles of O3-exposed spruce needles as measured by time-correlated single photon counting. New Phytologist, 122 (3). pp. 501-506. ISSN 1469-8137

Abstract

Chlorophyll fluorescence decay profiles have been measured in the wavelength range 680–720 nm for needles from Norway spruce [Picea abies (L.) Karst] trees which have been exposed to ozone. All profiles required three exponential components of lifetime 100–150 ps, 400–600 ps and 3.5–5.0 ns to fit the experimental data. Compared to control samples, the ozone-treated needles exhibited a greater amount of the longest-lived chlorophyll fluorescence and a redistribution in intensity for both the other components from 720 + to 690 nm. These observations are interpreted in terms of disruption of energy transfer and break-up of light-harvesting complexes on exposure to ozone. The potential for use of the technique in monitoring forest decline is discussed.