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A general review of the mountain pine beetle (Dendroctonus ponderosae Hopkins) - lodgepole pine (Pinus contorta Dougl.) complex, including previous broad-band remote sensing studies aimed at early detection, is provided. The main emphasis of this thesis is on the utility of waveform analysis, based on in-situ spectroscopy, to successfully differentiate between tree canopies experiencing various degrees of stress. Damage to the tree canopies was both beetle-induced and artificial. In support of the spectroscopy, foliar analysis was performed. In addition, for comparative purposes, large-scale color-infrared photographs were both visually interpreted and measured for dye layer densities. Further, airborne digital broad-band data for the same study site were also acquired and analyzed. Despite significant differences in pigmentation levels and moisture status, the analysis showed poor detection success with both the densitometry and visual interpretation of the color-infrared photographs. This is in sharp contrast with previous studies and is concluded to be attributed to the natural variation from year to year and from site to site. The analysis of the digital airborne data resulted in equally poor differentiation between healthy and damaged tree canopies. The main objective of utilizing waveform analysis to take advantage of anticipated pigmentation reductions in stressed trees yielded very positive results. There were significant blue-shifts in the red-edge positions of currently attacked tree canopies. The data suggest that in a situation where conventional detection means such as those based on photo sensitivity fail, a suitable red-edge threshold can be determined from attacked trees and used to successfully differentiate healthy from currently attacked lodgepole pines.
Ulf Runesson (Sat,) studied this question.