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Terrestrial Condition Assessment (TCA) Insect and Disease Hazard

Published by U.S. Forest Service | Department of Agriculture | Metadata Last Checked: January 27, 2026 | Last Modified: 2025-09-25
Direct Download (Raster Data Gateway)Objective: Identify areas with unhealthy forest conditions as evidenced by a combination of stand and environmental characteristics making them uncharacteristically vulnerable to insect and pathogen outbreaks.Data: The 2018 National Insect and Disease Risk Map (NIDRM) developed by USFS-FHAAST indicates locations where forests are stressed and susceptible to outbreaks of native and non-native insects and diseases. These include forests with overly high stand densities and where soil/site conditions contribute to drought. The basis for assigning risk is the expectation that 25% or more of live basal area (three times the natural background rate of mortality) will die over the next 15 years due to insects and diseases. Because the NIDRM 2018 map is the most recent update, it has been reused each year for TCA Assessments from 2020-present.Format: Raster data are binary: (1) at risk or (0) not at riskResolution: 240mSource: NIDRM 2018Additional Resources:Details on Method Changes and Source Data VersionsOverview of the Terrestrial Condition Assessment: TCA Hubsite or Landfire Office Hour PresentationExplore the results of the most recent assessment: TCA Interactive Data ViewerLearn more about the TCA KPI: TCA Dashboard*if you have trouble viewing the Dashboard, please submit a Tableau Viewer Access Request

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