Publication Date
2017
Journal or Book Title
Forests
Abstract
Introduced insects and pathogens impact millions of acres of forested land in the United States each year, and large-scale monitoring efforts are essential for tracking the spread of outbreaks and quantifying the extent of damage. However, monitoring the impacts of defoliating insects presents a significant challenge due to the ephemeral nature of defoliation events. Using the 2016 gypsy moth (Lymantria dispar) outbreak in Southern New England as a case study, we present a new approach for near-real-time defoliation monitoring using synthetic images produced from Landsat time series. By comparing predicted and observed images, we assessed changes in vegetation condition multiple times over the course of an outbreak. Initial measures can be made as imagery becomes available, and season-integrated products provide a wall-to-wall assessment of potential defoliation at 30 m resolution. Qualitative and quantitative comparisons suggest our Landsat Time Series (LTS) products improve identification of defoliation events relative to existing products and provide a repeatable metric of change in condition. Our synthetic-image approach is an important step toward using the full temporal potential of the Landsat archive for operational monitoring of forest health over large extents, and provides an important new tool for understanding spatial and temporal dynamics of insect defoliators.
DOI
https://doi.org/10.3390/f8080275
Volume
8
Issue
8
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
License
UMass Amherst Open Access Policy
Funder
UMass SOAR Fund
Recommended Citation
Pasquarella, Valerie J.; Bradley, Bethany A.; and Woodcock, Curtis E., "Near-Real-Time Monitoring of Insect Defoliation Using Landsat Time Series" (2017). Forests. 399.
https://doi.org/10.3390/f8080275