Plots, Planes, and Pixels: Data Integration for Improved Forest Mortality Monitoring

A forest with patches of trees damaged by mountain pine beetle. Mountain pine beetle can cause widespread damage to many species, often killing trees or leaving them vulnerable to other disturbances. Photo by USDA Forest Service, Coeur d'Alene Field Office. 

In 2022, the USDA Forest Service Forest Health Protection Aerial Detection Survey documented extensive mortality of true firs (Abies spp.) in Oregon. Several media outlets referred to this as “Firmageddon.” Large-scale tree mortality events such as this highlight the need for better information about forest disturbances and their effects so that land managers can anticipate and respond to ecosystem change in order to maintain productive forests.

Managers tasked with preserving forest health require timely, reliable information about (1) the spatial and temporal distribution of forest mortality events, (2) their ecological effects, and (3) vulnerability to future events and associated risk. Yet currently available datasets have unique temporal, spatial, and ecological characteristics that limit their individual usefulness for management decision making. We are addressing this by developing a framework for integrating field observations, aerial surveys, and satellite-based spectral data into a unified forest mortality and risk data product.

Keywords: biological disturbance, insects, remote sensing, data assimilation, Firmageddon

Existing approaches for monitoring biological forest disturbances and quantifying their impacts typically rely on individual data sources. These data differ in their approach to space, time, attribution, and ecological effects. These differences make it difficult to gain timely and comprehensive pictures of biological disturbance-related forest mortality on large scales. 

Initial proof-of-concept work has focused on mountain pine beetle outbreaks in southern and central Oregon. In these case studies, we reliably predicted forest basal area loss attributed to beetle outbreaks by using spectral change indices derived from satellite remote-sensing data. We are currently adapting this approach for use in detecting other forest disturbances and mortality events. The next goal is to focus on the chronology and drivers of the true fir mortality that occurred in 2021 and 2022 across southern Oregon. 

This work will provide land management decisionmakers with reliable, up-to-date estimates of the fine-scale impacts of biological disturbance agents on their forests. This will improve the ability to respond to past and ongoing outbreaks and mortality events, as well as gain a better understanding of future vulnerability and risk. 

Project Deliverables 

This project will produce: 

• R and GEE coding scripts for data integration
• Two publications: a review, intercomparison, and integration article and a vulnerability assessment
• A publicly available map of forest vulnerability in Oregon
• Presentations and a webinar for a federal and state agency forest health and protection audience