Nationwide Forest Inventory
The Forest Inventory and Analysis program collects, analyzes, and reports information on the status, trends, and condition of America’s forests: how much exists, where it exists, who owns it, and how it is changing, as well as how the trees and other forest vegetation are growing and how much has died or has been removed in recent years.
The program works with State and local forestry agencies, universities, and nongovernmental organizations to provide key data needed to assess the status, trends, and sustainability of the Nation's forests. The program is the only comprehensive, long-term, field-based inventory of forests and trees across all ownerships in the United States. The program covers the 50 states and affiliated Pacific and Atlantic islands.
The Nationwide Forest Inventory, a Forest Inventory and Analysis program, provides a diverse set of customers—federal and state policy makers to public and private landowners to managers—information used for many purposes. These data have been used to assess and monitor old growth, wildlife habitat, and the status and trends of whitebark pine; to identify areas of forest decline; and to track the effect of global change reflected in changing carbon storage and shifting species distributions. In addition to informing reports and analyses at the national, regional, state, and national forest level, information from the program is publicly available through our online database.
Plot-based field surveys are the backbone of the Nationwide Forest Inventory. With one plot per roughly 6,000 acres and a probabilistic sample design, the inventory allows us to provide unbiased estimates of forest characteristics across all ownerships. Plot data collection is conducted by federal field crews, state partners, or contractors. Data collection, data management, analysis, and reporting are coordinated by four units. The coordinates of the plot locations are confidential, as required by law, and we maintain tools that allow for analysis using the underlying plot data. These tools allow estimation of forest attributes at spatial scales ranging from national to state to county level.
The Nationwide Forest Inventory consists of a probabilistic sample of permanent plots installed across all forested lands (or lands capable of being forested) in the Nation. The sample design consists of one field plot for every 6,000 acres of forest. Field crews collect information on forest type, site attributes such as ownership and terrain, tree species, tree size, and overall tree condition. On a subset of sample plots, we measure a broader suite of attributes including understory vegetation, down woody material, and soil information. We send soil samples to a laboratory for chemical analysis. We measure each plot every five to ten years, depending on the state the plot falls within. Each step of the inventory process, from field preparation to publication of data and reports, goes through quality assurance procedures to ensure high data quality. We combine remote sensing data with plot data, using an analysis method known as post-stratified estimation, which produces more precise estimates of forest conditions than plot data alone.
You can find field protocols in the national core field guide. This document describes the standards, codes, methods, and definitions for field data consistent and uniform across all regional units.
Data Documentation
Data Download
| Data/Tool Name | Description |
|---|---|
| FIA DataMart | FIA DataMart allows visitors to download raw data files, standard tables, SQLite databases, Forest Vegetation Simulator (FVS) input files, and a desktop EVALIDator reporting tool. DataMart also provides access to the FIA State reports, FIADB load history, API EVALIDator, and FIADB User Guides. |
Data Analysis Tools
| Data/Tool Name | Description |
|---|---|
| BIGMAP | FIA's cloud-based national scale modeling, mapping, and analysis environment for US forests. This online platform combines FIA's NFI data with remote sensing and other datasets to produce maps of forest resources. |
| EVALIDator and FIADB-API | EVALIDator and FIADB-API allows users to produce a large variety of population estimates and their sampling errors based on the current FIA database. Estimates can be produced as totals (e.g., number of trees) or as ratios (e.g., number of trees per acre of forest land). |
| FIA DataMart | FIA DataMart allows visitors to download raw data files, standard tables, SQLite databases, Forest Vegetation Simulator (FVS) input files, and a desktop EVALIDator reporting tool. DataMart also provides access to the FIA State reports, FIADB load history, API EVALIDator, and FIADB User Guides. |
| FIA Geospatial Data Showcase | A showcase of FIA maps, tools, data and applications. |
| FIA Land Resources Explorer | The Land Resources Explorer is an interactive, user-friendly suite of tools for viewing land area estimates and maps form multiple information sources, including information on land use, land cover, and change. |
| FIA One-Click State Factsheets | Allows users to view FIA snapshots of a state’s forest land through an interactive tool. Select the desired state to produce a real-time factsheet based on the most currently available FIA data. |
Data Requests
| Data/Tool Name | Description |
|---|---|
| Data Consultations and Requests |
|
| Spatial Data Services | In order to protect the privacy of landowners and the integrity of the FIA sample, the exact coordinates of plot locations are kept confidential. Exact plot locations are protected by federal law. Therefore, actual FIA plot locations are very rarely shared and only under a specific, limited set of circumstances. Visit the Spatial Data Services page to learn more. |
Key Personnel
National Contacts
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Person
Sara A. Goeking, PhD
Forest Inventory and Analysis National Program Managerhttps://research.fs.usda.gov/about/people/sara.goeking -
Person
Linda S. Heath, PhD
Director, IMARhttps://research.fs.usda.gov/about/people/linda.heath
Regional Contacts
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Person
Sharon Stanton, PhD
PNW Research Station FIA Program Managerhttps://research.fs.usda.gov/about/people/sharon.stanton -
Person
Charles H. (Hobie) Perry, PhD
Supervisory Biological Scientisthttps://research.fs.usda.gov/about/people/charles.h.perry -
Person
Burl Carraway
SRS FIA Program Managerhttps://research.fs.usda.gov/about/people/ausley.carraway -
Person
Kristen A. Pelz, PhD
Foresterhttps://research.fs.usda.gov/about/people/kristen.pelz
Sampling and Estimation Documentation
- Jim Westfall, John W. Coulston, Gretchen Moisen, Hans Andersen. 2022. Sampling and estimation documentation for the Enhanced Forest Inventory and Analysis Program: 2022
- William Bechtold, Paul L. Patterson, [Editors]. 2005. The enhanced forest inventory and analysis program - national sampling design and estimation procedures
Business and Organizational Documents
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Strategic Plan
https://research.fs.usda.gov/understory/forest-inventory-and-analysis-strategic-plan -
Business Report
https://research.fs.usda.gov/understory/2024-forest-inventory-and-analysis-business-report
Additional Resources
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User Guide
https://research.fs.usda.gov/understory/forest-inventory-and-analysis-database-user-guide-nfi -
Guide
https://research.fs.usda.gov/understory/nationwide-forest-inventory-field-guide -
User Guide
https://research.fs.usda.gov/understory/fiadb-population-estimation-user-guide -
User Guide
https://research.fs.usda.gov/understory/forest-inventory-and-analysis-glossary-standard-terminology
Contributions to National and Global Reporting
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Resources Planning Act Assessment
The Resources Planning Act Assessment is a decadal examination of the status, trends, and projected 50-year futures of the Nation’s renewable resources across all ownerships. Forest Inventory and Analsysis data is analyzed on a five-year cycle to produce The Forest Resources of the United States, a supporting document to the Assessment that provides in-depth information on the status and trends of forest resources across the United States.
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National Report on Sustainable Forests
Forest Inventory and Analysis data is an essential foundation for the National Report on Sustainable Forests and its 54 indicators of forests sustainability, particularly those indicators covering forest extent, structure, and productivity. Without this data, the National Report would not be possible.
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United National Food and Agriculture Organization Global Forest Resources Assessment
Data concerning the state of the Nation’s forests reported by the United States to the Global Forest Resources Assessment and assembled by the United Nations Food and Agriculture Organization come almost exclusively from the Forest Inventory and Analysis program.
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Greenhouse gas inventories to the United Nations Framework Convention for Climate Change
Forest Inventory and Analysis estimates of carbon in forests are crucial for the United States national reporting of greenhouse gas inventories to the United Nations Framework Convention for Climate Change.
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The North American Forest Database
This platform enhances North American forest inventory and monitoring data integration that complements the national forest assessment tools of Canada, Mexico and the United States and the United National Global Forest Resources Assessment.
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The Forest Service produces the authoritative research, analyses, and tools for carbon monitoring and estimation across the nation. The Forest Inventory and Analysis program is the foundation for data on forest carbon stocks and fluxes at all scales, from farm scale to the National Greenhouse Gas Inventory reporting for the United Nations Framework Convention on Climate Change, Forest Sustainability Reporting for the Montreal Process, carbon assessment across National Forests and Grasslands, and beyond.
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Fifth National Climate Assessment
The Fifth National Climate Assessment is the United States Government’s preeminent report on climate change impacts, risks, and responses. Forest Inventory and Analysis scientists and data contributed to the sections related to forests.