Forest Inventory and Analysis National Program

FIA Library

Sampling and Estimation Documentation 

The National Sampling Design and Estimation Procedures documentation presents an overview of the annual inventory concept, explains the three phases of FIA's sampling design, describes the sampling frame and plot configuration, presents the estimators that form the basis of FIA's National Information Management System (NIMS), and shows how annual data are combined for analysis. It also references a number of Web-based supplementary documents that provide greater detail about some of the more obscure aspects of the sampling and estimation system, as well as examples of calculations for most of the common estimators produced by FIA.

Sampling and Estimation Documentation for the Enhanced Forest Inventory and Analysis Program: 2022
Westfall, James A.; Coulston, John W.; Moisen, Gretchen G.; Andersen, Hans-Erik; [Comps], 2022 (PDF 4.0 MB) 


Additional Documentation:

Urban FIA:
Strategic National Urban Forest Inventory for the United States (PDF 6.0MB) Integrating urban and national forest inventory data in support of rural-urban assessments (PDF 510KB)

National Woodland Owner Survey (NWOS)
Weighting for the U.S. Forest Service, National Woodland Owner Survey (PDF 1.98MB) NWOS: An R Package for Working with USFS NWOS Survey Data (v1.0) NWOS Dashboard (2019)

Timber Products Output (TPO):
Coming soon!

FIA Carbon Attributes:
Coming soon!

Alternative Estimators:
FIESTA Analytical Tool A Tutorial on Model-Assisted Estimation with Application to Forest Inventory (PDF 3.5MB) Enhancing the precision of broad-scale forestland removals estimates with small area estimation techniques (PDF 1.0MB) A novel application of small area estimation in loblolly pine forest inventory (PDF 1.1MB) 2020 SAE Focus Session Summary (PDF 1.2MB) 2020 SAE Focus Session - Applied Science Presentations (PDF 313KB) Photo-Based Estimators for the Nevada Photo-Based Inventory (PDF 3.9MB) Georgia Pilot: Can Remote Sensing Observations Augment Traditional Forest Inventory Data? (PDF 1.7MB)

The Enhanced Forest Inventory and Analysis Program – National Sampling Design and Estimation Procedures
Bechtold, William A.; Patterson, Paul l.; [Editors], 2005 (PDF 2.6MB) 

Supporting Documents:

The Hexagon/Panel System for Selecting FIA Plots under an Annual Inventory (PDF 233KB)

FIA Tree Volume and Biomass Calculations (PDF 408KB)

Examples of FIA Point-in-Time Estimation Procedures for Several Common Cases (XLS 609KB)

Examples of FIA Change-Component Estimation Procedures for Several Common Cases (XLS 657KB)

Computation of FIA Plot Expansion Factors (PDF 22KB)

Archive/Historic Documents:
National Algorithms for Determining Stocking Class, Stand Size Class, and Forest Type for Forest Inventory and Analysis Plots (PDF 239KB) FIA Volume Calculations (PDF 203KB)

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