Evaluation of Landsat Thematic Mapper Data for Mapping Top Kill Caused by Jack Pine Budworm Defoliation

Surveying mountain pine beetle damage of forests: A review of remote sensing opportunities

“…Techniques applicable to these operations could be developed by further research, especially using digital remotely sensed data. The mapping of defoliation can be confounded by issues around the mixture of healthy and defoliated vegetation occurring together in a stand (Leckie, 1987;Hall et al, 1995). Defoliation is more consistently distinguishable from healthy trees when there is larger percentage of mortality within a stand (Vogelmann and Rock, 1986;Leckie, 1987;Wastenson et al, 1987).…”

Automated detection and mapping of crown discolouration caused by jack pine budworm with 2.5 m resolution multispectral imagery

“…Difficulties arise in acquiring imagery during the short temporal window of peak discolouration, from confusion caused by varying stand density, hardwood component and presence of non-susceptible conifer species, and because of the lack of spatial detail (Leckie, 1987;Ekstrand, 1994;Radeloff et al, 1999). Satellite imagery has also been examined for assessment of jack pine budworm top kill (Hall et al, 1995a) and cumulative defoliation or total loss of foliage and mortality (Hopkins et al, 1988). Although symptoms and damage mechanisms are different, several other insect, disease and stressing agents that cause discolouration have also been examined at various resolutions.…”

Remote sensing of forest pest damage: a review and lessons learned from a Canadian perspective

“…The earliest study seems to be that by Hopkins et al (1988), who employed a supervised maximum likelihood algorithm with a single-date Landsat 5 TM image from which moderate, severe, and dead defoliation classes were classified with high accuracy. Hall et al (1995) mapped jack pine budworm top kill using before and after Landsat TM imagery and only found small spectral differences between different severity levels, with overall accuracies ranging from 70% to 73% with three classes which were partly explained by the influence of the understorey in the spectral response of mature jack pine stands. A spectral mixture analysis approach was employed with Landsat TM imagery acquired at pre-defoliation and peak-defoliation time periods, from which actual jack pine budworm defoliation was determined with high accuracy in pure stands of jack pine and in mixed stands with oak (Quercus Linnaeus; Fagaceae) as a deciduous component (Radeloff et al 1999).…”

“…For example, the degree of red discolouration caused by jack pine budworm defoliation is a visible indicator of damage severity used during aerial surveys (Volney 1988). When it is part of the symptoms, the discolouration is also likely the stage at which the greatest spectral change occurs relative to healthy trees (Hall et al 1995). For bark beetles, damage is typically manifested as a delayed change in colour and loss of foliage during the year(s) after the attack (Safranyik 1995;Shore et al 2006).…”