17 June 1993 Time-resolved chlorophyll fluorescence for early detection of forest decline
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Proceedings Volume 1922, Laser Study of Macroscopic Biosystems; (1993) https://doi.org/10.1117/12.146171
Event: Laser Spectroscopy of Biomolecules: 4th International Conference on Laser Applications in Life Sciences, 1992, Jyvaskyla, Finland
Aiming to an early detection of forest decline, prompt and delayed luminescence of spruce needles was studied from the picosecond to the second time range using novel laser diodes and highly sensitive detection systems. In particular, (1) subnanosecond fluorescence decay measurements showed a superposition of at least three exponentially decaying components, the largest of which (decay time (tau) equals 2.0 - 3.5 ns) represented some `dead' chlorophyll or closed reaction centers. This component is more pronounced in slightly damaged than in healthy spruces and can be used to monitor the early steps of photosynthesis. (2) Delayed luminescence -- which is supposed to report on the electron transport chain as a whole -- could also be correlated with the physiological state of the individual spruce. In general, healthy and declined spruces showed the highest photosynthetic efficiencies during the summer period, but also the most pronounced stress symptoms -- probably due to high irradiance, drought, and increased ozone concentrations.
© (1993) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Herbert Schneckenburger, Werner Schmidt, "Time-resolved chlorophyll fluorescence for early detection of forest decline", Proc. SPIE 1922, Laser Study of Macroscopic Biosystems, (17 June 1993); doi: 10.1117/12.146171; https://doi.org/10.1117/12.146171

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