Modeling a historical mountain pine beetle outbreak using Landsat MSS and multiple lines of evidence

Remote Sensing of Environment
By: , and 

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Abstract

Mountain pine beetles are significant forest disturbance agents, capable of inducing widespread mortality in coniferous forests in western North America. Various remote sensing approaches have assessed the impacts of beetle outbreaks over the last two decades. However, few studies have addressed the impacts of historical mountain pine beetle outbreaks, including the 1970s event that impacted Glacier National Park. The lack of spatially explicit data on this disturbance represents both a major data gap and a critical research challenge in that wildfire has removed some of the evidence from the landscape. We utilized multiple lines of evidence to model forest canopy mortality as a proxy for outbreak severity. We incorporate historical aerial and landscape photos, aerial detection survey data, a nine-year collection of satellite imagery and abiotic data. This study presents a remote sensing based framework to (1) relate measurements of canopy mortality from fine-scale aerial photography to coarse-scale multispectral imagery and (2) classify the severity of mountain pine beetle affected areas using a temporal sequence of Landsat data and other landscape variables. We sampled canopy mortality in 261 plots from aerial photos and found that insect effects on mortality were evident in changes to the Normalized Difference Vegetation Index (NDVI) over time. We tested multiple spectral indices and found that a combination of NDVI and the green band resulted in the strongest model. We report a two-step process where we utilize a generalized least squares model to account for the large-scale variability in the data and a binary regression tree to describe the small-scale variability. The final model had a root mean square error estimate of 9.8% canopy mortality, a mean absolute error of 7.6% and an R2 of 0.82. The results demonstrate that a model of percent canopy mortality as a continuous variable can be developed to identify a gradient of mountain pine beetle severity on the landscape.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Modeling a historical mountain pine beetle outbreak using Landsat MSS and multiple lines of evidence
Series title Remote Sensing of Environment
DOI 10.1016/j.rse.2014.09.002
Volume 155
Year Published 2014
Language English
Publisher Elsevier
Contributing office(s) Fort Collins Science Center
Description 14 p.
First page 275
Last page 288
Country United States
State Montana
Other Geospatial Glacier National Park
Online Only (Y/N) N
Additional Online Files (Y/N) N