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Pacific Northwest Research Station

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Western Wildland Environmental Threat Assessment Center

WWETAC develops and communicates the latest scientific understanding of environmental threats to the western United States. We conduct applied science, provide tools, and produce information to help land managers assess and respond to environmental threats, leading to more resilient and productive landscapes.

Western Wildland Environmental Threat Assessment Center

The Western Wildland Environmental Threat Assessment Center (WWETAC) is administered by the Pacific Northwest Research Station, and it covers the western half of the United States. WWETAC collaborates with the Forest Service Rocky Mountain Research Station and the Pacific Southwest Research Station, Regions 1-6 and 10, as well as with universities and other partners across the West.

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Overview

Ecosystems of the western United States face a variety of threats, including drought, insect and disease outbreaks, invasive species, and uncharacteristically large and severe wildfires. 

At the Western Wildland Environmental Threat Assessment Center (WWETAC), we work with our partners in research and land management to:  

  • Monitor and assess threats to western lands
  • Synthesize the latest understanding of the causes and implications of environmental threats
  • Develop novel research and decision-support tools to help agencies, communities, and managers reduce negative effects and sustain productive ecosystems
WWETAC Coverage Map

Founded in 2005 along with the Eastern Forest Environmental Threat Assessment Center, WWETAC is a unit of the USDA Forest Service. WWETAC serves all seven Forest Service regions (1-6 and 10) in the western United States.

Our activities are organized into focus areas: 

Mission and Objectives 

WWETAC’s mission is to generate and integrate knowledge to provide credible prediction, early detection, and quantitative assessment of environmental threats to forests and rangelands in the western United States. Our objectives are to:

  • Assess risks, uncertainties, and potential effects of environmental stresses on western ecological conditions and socioeconomic values
  • Evaluate the effects and consequences of multiple, interacting stressors on western forest and rangeland health
  • Provide science-based decision-support tools for policy formulation and land management in the western United States
  • Provide land managers with credible predictions of potential severe disturbances in the West with sufficient warning to take preventive actions

Pre-fire prescribed burning, active wildfire, post-fire charred trees

Wildfire Risk and Fuel Management

Wildfire is a natural process in western U.S. forests and rangelands. However, high-severity wildfire is a major threat to western ecosystems and the goods and services they provide. High-severity wildfires increase the likelihood of other ecological impacts, including flooding, erosion, and reduction in water quality, as well as loss of key wildlife habitat, recreation resources, and other ecological and economic values. 

WWETAC conducts wildfire modeling and prioritizes research guiding pre-fire planning and post-fire management to maintain healthy and product forests and rangelands. Researchers are gathering information on wildfire behavior, drivers of megafires, and historical fire regimes on western landscapes. This information is then used to determine how management may need to adapt to changing conditions. 

Measuring Long-Term Seedling Survival
 

Selected WWETAC Wildfire Publications

Publications

Effective beginning 5/30/2025

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WWETAC Climate Change: wildfire, flood, drought, invasives

Climate Change 

Climate change is a growing threat to western ecosystems and society. Climate change is expected to be a "threat multiplier" in that it is likely to exacerbate many existing threats to western forests and rangelands, including drought, wildfire, insect outbreaks, and invasive plants.

One of WWETAC's greatest challenges and highest priorities is translating projected climatic conditions into potential effects on western ecosystems, natural resource availability, and the societies dependent on them.

Selected WWETAC Climate Change Publications

Publications

Three pictures of invasive plants in the Western U.S. A tree covered in climbing english ivy. A bunch of flowering reed canary grass. A scotch broom bush covered in small yellow flowers

Invasive Species

Plants and animals that move or are introduced to a new location can threaten ecosystems throughout the western United States. At times, these introductions pose no threat, but sometimes non-native species spread and multiply in their new habitats, invading and displacing native species and altering ecosystem structure and function. Invasive species can also reduce the viability of threatened or endangered native species, reduce water availability to native species, change nutrient dynamics and balance, and limit the ability of forests to sequester carbon. These effects can have negative repercussions on forest and rangeland productivity, recreation resources, and overall ecosystem integrity. WWETAC prioritizes research at the forefront of invasive species outbreaks and develops information and tools to help managers effectively respond to these novel threats.  

Selected WWETAC Invasive Species Publications

Three images of forest insect disease impacts. A ghostly, partially defoliated conifer forest. A birch leaf with amber spots from birch leaf miners. A forest professional in a hazard suit spraying a tree as a bark beetle treatment

Insects & Disease

Many insects and diseases are native to the western U.S. However, they can still cause considerable damage, especially when natural disturbance cycles are amplified by magnifying factors like drought. In these circumstances, they can cause widescale damage and loss to forest and rangelands.

Understanding the mechanisms behind native insect outbreaks and disease spread is important for managing these threats. WWETAC investigates native insects and pathogens that have reached uncharacteristic or harmful levels to help land managers determine the best way to respond. 

Selected WWETAC Insect & Disease Publications

Three images. A hillside of mixed live and dead trees, a lone yellowing oak tree in a field of dead grass, a close-up picture of a smoldering stump

Drought in the West

Drought is a natural part of western lands. Extreme or prolonged drought can have significant effects on forests and grasslands. Drought interacts with other disturbances in complex ways like changing fire behavior, altering forest insect outbreak patterns, or opening opportunities for invasive species to spread.  

WWETAC investigates how drought affects western forests and grasslands, provides tools to assist with management, and provides timely drought status updates to help land managers prepare for drought effects.

Selected WWETAC Drought Publications

Tools

Videos & Podcasts

Fact Sheets

Webinars

Projects

Publications

Last updated September 24, 2025