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Using hyperspectral imagery to estimate forest floor consumption from wildfire in boreal forests of Alaska, USA
Lewis, S.A.; Hudak, A.T.; Ottmar, R.D.; Robichaud, P.R.; Lentile, L.B.; Hood, S.M.; Cronan, J.B.; Morgan, P. 2011.
Using hyperspectral imagery to estimate forest floor consumption from wildfire in boreal forests of Alaska, USA.
International Journal of Wildland Fire 20:255-271.
Keywords: burn severity, carbon, duff, hyperspectral remote sensing, moss, hyperspectral, ground cover
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Abstract:
Wildfire is a major forest disturbance in interior Alaska that can both directly and indirectly alter ecological
processes. We used a combination of pre- and post-fire forest floor depths and post-fire ground cover assessments
measured in the field, and high-resolution airborne hyperspectral imagery, to map forest floor conditions after the 2004
Taylor Complex in Alaska.s boreal forest. We applied a linear spectral unmixing model with five endmembers
representing green moss, non-photosynthetic moss, charred moss, ash and soil to reflectance data to produce fractional
cover maps. Our study sites spanned low to moderately high burn severity, and both black and white spruce forest types;
high cover of green or non-photosynthetic moss in the remotely sensed imagery indicated low consumption, whereas high
cover of charred moss, ash or soil indicated higher consumption. Strong relationships (R2=0.5 to 0.6) between green moss
estimated from the imagery and both post-fire depth and percentage consumption suggest that potential burn severity may
be predicted by a map of green (live) moss. Given that the depth of the post-fire forest floor is ecologically significant, the
method of mapping the condition of the organic forest floor with hyperspectral imagery presented here may be a useful tool
to assess the effect of future fires in the boreal region.
Moscow FSL publication no. 2011b
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