Forest Pest Detection and Tracking through Harmonized Remote Sensing and Data Synthesis

Photo Credit

Landsat data were obtained from the USGS EarthExplorer for this analysis.

An area of the Peshtigo River State Forest in Marinette County, Wisconsin, where the invasive spongy moth (Lymantria dispar) had an outbreak event in summer 2023. Though the damage from the outbreak is not as severe as in forest thinning or clearcut areas, forests are sensitive to even moderate outbreaks of insects and pathogens that can affect tree health and normal growth functions. Red areas show impaired forest health; green areas show improved forest health. 

Invasive forest insects and pathogens pose threats to forest health, management objectives, and biodiversity. Traditional methods for monitoring pest invasions rely heavily on direct observations. These methods are unevenly applied and often miss important invasive events leaving broad areas vulnerable to invasive pests.

Disturbances by forest insects and pathogens are more subtle in their effects relative to stand-replacing disturbances (e.g., logging, fire). Insect- and pathogen-based forest disturbances are challenging to detect. Tree defoliation, morbidity, and mortality may cover small areas and may be slow to develop. Many pests are species-specific, and detailed information on forest composition is needed to home in on possible infestations. Effects of biotic disturbances may be indistinguishable from “normal” seasonal variations in forests due to weather and stresses such as drought or severe storms.

More specific diagnoses of causal disturbance agents may be achieved through knowledge of their physiological effects on the trees. Datasets from the U.S. Forest Service Forest Inventory and Analysis program, and other observational data, will help pinpoint conditions under which disturbances may be occurring. This information will help scientists distinguish between native and invasive species and track their effects on the forest over time. 

Objectives

• Develop a computational system for detecting new forest disturbances that may be caused, or enhanced, by invasive insects and pathogens.
• Develop a prototype web-based application for mapping, classifying, and describing forest disturbances, including invasive species.
• Develop an assessment that will determine the accuracy of disturbance map products.

Expected Results

Outputs

• Synthesis of biotic (e.g., insects, pathogens) disturbance agents in the Forest Service’s Region 9.
• Compilation of weather and climate data and remote sensing satellite images for the region.
• Validation of pest disturbance maps using Forest Inventory and Analysis data, aerial surveys and fire boundaries and severity datasets.
• Procedures for disturbance detection and classification.  

Expected Outcomes

• Development of a prototype web-based application for mapping, classifying, and describing forest disturbances, including invasive species, within U.S. Forest Service Region 9.
• Expansion of the U.S. Forest Service portfolio on disturbance detection tools with a focus on high-priority invasive pest damage areas. 

Metrics of Success

Successful utilization of the web-based application for mapping, classifying, and describing forest disturbances, including invasive species.

Geographies and High-Risk Landscapes to Be Addressed

Regional: The initial testbed region will focus on northern Minnesota, Wisconsin and Michigan. Following the successful application of analysis and mapping methods the project will then expand the territory cover additional areas to the east and south within National Forest System’s Region 9.