The Forest Inventory and Analysis 

Database: Database Description and 

Users Manual Version 4.0 for Phase 2

Sharon W. Woudenberg, Barbara L. Conkling, 

Barbara M. O’Connell, Elizabeth B. LaPoint, 

Jeffery A. Turner, Karen L. Waddell

United States Department of Agriculture

Forest Service

Rocky Mountain Research Station

General Technical Report RMRS-GTR-245

December 2010

Column

CN

PLT_CN

PREV_TRE_CN

INVYR

STATECD

UNITCD

COUNTYCD

PLOT

SUBP

TREE

TREE

CONDID

AZIMUTH

DIST

PREVCOND

STATUSCD

SPCD

SPGRPCD

DIA

DIAHTCD

HT

HTCD

TREECLCD

CR

CCLCD

TREEGRCD

AGENTCD

CULL

DAMLOC1

ABC

ABC

ABC

123

123

123

123

123

123

123

123

123

123

123

123

123

123

123

123

123

123

123

123

123

123

123

123

123

X

Column

CN

SRV_CN

CTY_CN

PREV_PLT_CN

INVYR

STATECD

UNITCD

COUNTYCD

PLOT

PLOT_STATUS_CD

PLOT

ABC

ABC

ABC

123

123

123

123

123

123

X

ABC

2

1

4 3

TPA = 1/(4*0.04154172)
Woudenberg, Sharon W.; Conkling, Barbara L.; O’Connell, Barbara M.; LaPoint, Elizabeth B.; 

Turner, Jeffery A.; Waddell, Karen L. 2010. The Forest Inventory and Analysis Database: 

Database description and users manual version 4.0 for Phase 2. Gen. Tech. Rep. RMRSGTR-245. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain 

Research Station. 336 p.

Abstract

This document is based on previous documentation of the nationally standardized Forest

Inventory and Analysis database (Hansen and others 1992; Woudenberg and Farrenkopf 1995; 

Miles and others 2001). Documentation of the structure of the Forest Inventory and Analysis 

database (FIADB) for Phase 2 data, as well as codes and definitions, is provided. Examples for 

producing population level estimates are also presented. This database provides a consistent 

framework for storing forest inventory data across all ownerships for the entire United States. 

These data are available to the public.

Keywords: Forest Inventory and Analysis, inventory database, users manual, monitoring

You may order additional copies of this publication by sending your 

mailing information in label form through one of the following media. 

Please specify the publication title and number.

Publishing Services

Telephone (970) 498-1392

FAX (970) 498-1122

E-mail rschneider@fs.fed.us

Web site http://www.fs.fed.us/rmrs

Mailing Address Publications Distribution

Rocky Mountain Research Station

240 West Prospect Road

Fort Collins, CO 80526

Authors

Sharon W. Woudenberg is a Supervisory Forester with the Inventory and Monitoring Program, 

USDA Forest Service, Rocky Mountain Research Station, Ogden, Utah.

Barbara L. Conkling is a Research Assistant Professor in the Department of Forestry and

Environmental Resources, North Carolina State University, Raleigh, North Carolina.

Barbara M. O’Connell is a Forester with the Forest Inventory and Analysis Program, USDA Forest 

Service, Northern Research Station, Newtown Square, Pennsylvania.

Elizabeth B. LaPoint is a Forester with the Natural Resources Inventory, Monitoring and

Assessment Program, Northern Research Station, Durham, New Hampshire.

Jeffery A. Turner is a Forester with the Forest Inventory and Analysis Program, USDA Forest Service, 

Southern Research Station, Knoxville, Tennessee.

Karen L. Waddell is a Forester with the Resource Monitoring and Assessment Program, USDA 

Forest Service, Pacific Northwest Research Station, Portland, Oregon.
The use of trade or firm names in this publication is for reader information and does not 

imply endorsement by the U.S. Department of Agriculture of any product or service.

Preface

Forest Inventory and Analysis (FIA) is a continuing 

endeavor mandated by Congress in the Forest and 

Rangeland Renewable Resources Planning Act of 

1974 and the McSweeney-McNary Forest Research 

Act of 1928. FIA’s primary objective is to determine 

the extent, condition, volume, growth, and depletion 

of timber on the Nation’s forest land. Before 1999, all 

inventories were conducted on a periodic basis. The 

passage of the 1998 Farm Bill requires FIA to collect 

data annually on plots within each State. This kind of 

up-to-date information is essential to frame realistic 

forest policies and programs. USDA Forest Service 

regional research stations are responsible for conducting these inventories and publishing summary reports 

for individual States.

In addition to published reports, the Forest Service 

provides data collected in each inventory to those 

interested in further analysis. This report describes a 

standard format in which data can be obtained. This 

standard format, referred to as the Forest Inventory and 

Analysis Database (FIADB) structure, was developed 

to provide users with as much data as possible in a 

consistent manner among States. A number of inventories conducted prior to the implementation of the 

annual inventory are available in the FIADB. However, 

various data attributes may be empty or the items may 

have been collected or computed differently. Annual 

inventories use a common plot design and common 

data collection procedures nationwide, resulting in 

greater consistency among FIA work units than earlier 

inventories. Data field definitions note inconsistencies 

caused by different sampling designs and processing 

methods.

Acknowledgments

In addition to those listed as authors, the following 

people provided additional contributions to this 

document:

George Breazeale, Computer Specialist, USDA 

Forest Service, Pacific Northwest Research Station, 

Portland, Oregon. Brian Cordova, Computer 

Programmer/Analyst, Harry Reid Center for 

Environmental Studies, University of Nevada-Las 

Vegas, Las Vegas, Nevada. Joseph Donnegan, 

Supervisory Biological Scientist, USDA Forest 

Service, Pacific Northwest Research Station, Portland, 

Oregon. Mark Hansen, Research Forester (retired), 

Forest Inventory and Analysis Program, USDA Forest 

Service, Northern Research Station, Saint Paul, 

Minnesota (currently Research Associate, Department 

of Forest Resources, University of Minnesota, Saint 

Paul, Minnesota). Jason R. Meade, Forester, USDA 

Forest Service, Southern Research Station, Knoxville, 

Tennessee. James Menlove, Ecologist, USDA Forest 

Service, Rocky Mountain Research Station, Ogden, 

Utah. Patrick Miles, Research Forester, USDA Forest 

Service, Northern Research Station, Saint Paul, 

Minnesota. Scott A. Pugh, Forester, USDA Forest 

Service, Northern Research Station, Houghton, 

Michigan. Ted Ridley, IT Specialist, USDA Forest 

Service, Southern Research Station, Knoxville, 

Tennessee. John D. Shaw, Biological Scientist, USDA 

Forest Service, Rocky Mountain Research Station, 

Inventory and Monitoring Program, Ogden, Utah.

Research support was provided by the USDA Forest 

Service Research Stations listed above and in part 

through the Research Joint Venture Agreements 

and 07-JV-11330146-134, 08-JV-11330146-078, and 

09-JV-11330146-087 between the U.S. Department 

of Agriculture, Forest Service, Southern Research 

Station, and North Carolina State University. 

i
ii
Contents

Preface .......................................................................................................................................................... i

Acknowledgments ........................................................................................................................................ i

Chapter 1 — Introduction .........................................................................................................................1

Purpose of this Manual ....................................................................................................................... 1

The FIA Program ................................................................................................................................ 2

The FIA Database .............................................................................................................................. 3

Changes From the Previous Database Version ................................................................................. 4

Chapter 2 — FIA Sampling and Estimation Procedures.........................................................................8

Sampling and Stratification Methodology ............................................................................................ 8

Plot Location ....................................................................................................................................... 8

Plot Design, Condition Delineation, and Types of Data Attributes..................................................... 10

Types of Attributes ............................................................................................................................ 11

Expansion factors ............................................................................................................................. 13

Accuracy Standards ......................................................................................................................... 14

Chapter 3 — Database Structure ........................................................................................................... 16

Table Descriptions .............................................................................................................................. 16

Keys Presented with the Tables ..........................................................................................................22

Survey Table (Oracle table name is SURVEY) .................................................................................. 24

County Table (Oracle table name is COUNTY) .................................................................................. 28

Plot Table (Oracle table name is PLOT) ............................................................................................. 30

Condition Table (Oracle table name is COND) .................................................................................. 43

Subplot Table (Oracle table name is SUBPLOT)................................................................................ 73

Subplot Condition Table (Oracle table name is SUBP_COND) ......................................................... 80

Tree Table (Oracle table name is TREE) ........................................................................................... 84

Seedling Table (Oracle table name is SEEDLING) .......................................................................... 119

Site Tree Table (Oracle table name is SITETREE) .......................................................................... 124

Boundary Table (Oracle table name is BOUNDARY) ....................................................................... 130

Subplot Condition Change Matrix (Oracle table name is SUBP_COND_CHNG_MTRX) ................ 135

Tree Regional Biomass Table (Oracle table name is TREE_REGIONAL_BIOMASS) .................... 139

Population Estimation Unit Table (Oracle table name is POP_ESTN_UNIT) .................................. 141

Population Evaluation Table (Oracle table name is POP_EVAL) ..................................................... 144

Population Evaluation Attribute Table (Oracle table name is POP_EVAL_ATTRIBUTE) ................. 147

Population Evaluation Group Table (Oracle table name is POP_EVAL_GRP) ................................ 149

Population Evaluation Type Table (Oracle table name is POP_EVAL_TYP) ....................................153

Population Plot Stratum Assignment Table (Oracle table name is

 POP_PLOT_STRATUM_ASSGN) ................................................................................................. 155

Population Stratum Table (Oracle table name is POP_STRATUM) ................................................. 159

Reference Population Attribute Table (Oracle table name is REF_POP_ATTRIBUTE) ................... 163

iii
Reference Population Evaluation Type Description Table (Oracle table name is

 REF_POP_EVAL_TYP_DESCR) ................................................................................................. 165

Reference Forest Type Table (Oracle table name is REF_FOREST_TYPE) .................................. 167

Reference Species Table (Oracle table name is REF_SPECIES).................................................... 169

Reference Species Group Table (Oracle table name is REF_SPECIES_GROUP) ......................... 184

Reference Habitat Type Description Table (Oracle table name is REF_HABTYP_DESCRIPTION) 186

Reference Habitat Type Publication Table (Oracle table name is REF_HABTYP_PUBLICATION) 188

Reference Citation Table (Oracle table name is REF_CITATION) ................................................... 190

Reference Forest Inventory and Analysis Database Version Table (Oracle table name is

 REF_FIADB_VERSION) ............................................................................................................ 192

Reference State Elevation Table (Oracle table name is REF_STATE_ELEV) ................................. 194

Reference Unit Table (Oracle table name is REF_UNIT) ................................................................. 196

Chapter 4 — Calculating Population Estimates and Their Associated Sampling Errors .............. 198

Literature Cited ....................................................................................................................................... 241

Appendix A. Index of Column Names ..................................................................................................... 243

Appendix B. Forest Inventory and Analysis (FIA) Plot Design Codes and Definitions by

 FIA Work Unit. .................................................................................................................................. 259

Appendix C. State, Survey Unit, and County Codes .............................................................................. 264

Appendix D. Forest Type Codes and Names .......................................................................................... 306

Appendix E. Administrative National Forest Codes and Names ............................................................. 310

Appendix F. Tree Species Codes, Names, and Occurrences...................................................................313

Appendix G. Tree Species Group Codes ............................................................................................... 322

Appendix H. Damage Agent codes for PNW .......................................................................................... 323

Appendix I. FIA Inventories by State, Year, and Type ............................................................................. 328

Appendix J. Biomass Estimation in the FIADB ....................................................................................... 330

iv
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 1 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 1

Chapter 1 -- Introduction 

Purpose of This Manual 

This manual is the definitive guide to the Forest Inventory and Analysis database (FIADB). This 

document replaces General Technical Report NC-218 (Miles and others 2001), which covered 

version 1.0 of the FIADB, and subsequent updates that appeared as online documentation to the 

FIADB through version 3.0. Although it is used widely within the Forest Inventory and Analysis 

(FIA) program, a substantial part, if not the majority, of the intended audience includes those 

outside FIA who are interested in using FIA data for their own analyses. Awareness of the potential 

uses of FIA data by users outside the FIA community is growing, and the data become increasingly 

useful as additional attributes are collected. However, as is the case with any data source, it is 

incumbent upon the user to understand not only the data definitions and acquisition methods, but 

also the context in which the data were collected. This manual is intended to help current and 

potential users understand the necessary details of the FIADB. 

This manual has four chapters. The remainder of chapter 1 includes general introductions to the FIA 

program and the FIA database, including brief histories of both. It provides a convenient overview 

for those who have an interest in using FIA data, but have not yet become familiar with the FIA 

program. Chapter 2 provides descriptions of FIA sampling methods, including plot location and 

design, data measurement and computation, and general estimation procedures. Chapter 3 describes 

the tables that comprise the database, the attributes stored in each table, and the linkages between 

tables. Descriptions of the attributes, their data format, valid values, and other important details are 

given, but the appropriate field manuals should be consulted for exact specifications regarding data 

collection methods. Users with a good understanding of chapter 3 and fundamental database 

management skills should be able to conduct a wide range of analyses. Chapter 4 explains the 

standard methods used to compile population-level estimates from FIADB, and applies the new 

estimation procedures documented by Bechtold and Patterson (2005). These procedures are based 

on adoption of the annual inventory system and the mapped plot design, and constitute a major 

change when compared to previous compilation procedures. However, the new compilation 

procedures should allow more flexible analyses, especially as additional panels are completed under 

the annual inventory system. 

There are several conventions used in this manual. The names of attributes (i.e., columns within 

tables) and table names appear in capital letters (e.g., PLOT table). Some attribute names appear in 

two or more tables. In most cases, such as the State code (STATECD), the attribute has the same 

definition in all tables. However, there are situations where attributes with the same name are 

defined differently in each table. One such example is the VALUE attribute in the 

REF_FOREST_TYPE table, which is used to identify the forest type and refers to appendix D. 

However, the VALUE attribute in the REF_UNIT table is used to indicate the FIA survey unit 

identification number from appendix C. In most cases, such as in the table descriptions in chapter 3, 

the attribute name will be used alone and the affiliation with a particular table is implied by the 

context. In cases where an attribute name has a different meaning in two or more tables, a 

compound naming convention, using the table name followed by the attribute name, will be used. In 

the VALUE attribute example, the name REF_FOREST_TYPE.VALUE refers to the VALUE 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

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2 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

attribute in the REF_FOREST_TYPE table, while REF_UNIT.VALUE refers to the VALUE 

attribute in the REF_UNIT table. 

The FIA Program 

The FIA program is mandated by Congress in the Forest and Rangeland Renewable Resources 

Planning Act of 1974 and the McSweeney-McNary Forest Research Act of 1928. The mission of 

FIA is to determine the extent, condition, volume, growth, and depletions of timber on the Nation's 

forest land. FIA is the only program that collects, publishes, and analyzes data from all ownerships 

of forest land in the United States (Smith 2002). Throughout the 80-year history of the program, 

inventories have been conducted by a number of geographically dispersed FIA work units. 

Currently, the national FIA program is implemented by four regionally distributed work units that 

are coordinated by a National Office in Washington, DC (see figure 1). The four FIA work units are 

named by the Research Station in which they reside. Station abbreviations are used within this 

document and they are defined as Pacific Northwest Research Station (PNWRS), Northern 

Research Station (NRS), Rocky Mountain Research Station (RMRS), and Southern Research 

Station (SRS). NRS was recently formed from the merger of North Central Research Station 

(NCRS) and Northeastern Research Station (NERS). Some data items still retain these designations. 

Starting in 1929, FIA accomplished its mission by conducting periodic forest inventories on a Stateby-State basis. With the completion of Arizona, New Mexico, and Nevada in 1962, all 48 

coterminous States had at least one periodic inventory (Van Hooser and others 1993). Repeat 

intervals for inventorying individual States have varied widely. By the late 1990s, most States had 

been inventoried more than once under the periodic inventory system; however, not all periodic 

data are available in electronic form (appendix I lists all periodic data available in the FIADB and 

the year in which annual inventory began). 

Figure 1. Boundaries of the four regionally distributed FIA work units and 

locations of program offices. 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 3

With the passage of the 1998 Farm Bill, the FIA program was required to move from a periodic 

inventory to an annualized system, with a portion of all plots within a State measured each year 

(Gillespie 1999). Starting in 1999, States were phased into the annual inventory system (appendix I). 

At the time of publication of this document, annual inventory has not yet been started in Wyoming 

and Interior Alaska. Although the 1998 Farm Bill specified that 20 percent of the plots within each 

State would be visited annually, funding limitations have resulted in the actual portion of plots 

measured annually ranging between 10 and 20 percent, depending on the State. 

Periodic and annual data are analyzed to produce reports at State, regional, and national levels. In 

addition to published reports, data are made available to the public for those who are interested in 

conducting their own analyses. Downloadable data, available online at http://fia.fs.fed.us/toolsdata/, follow the format described in this document. Also available at this site are tools to make 

population estimates. The web-based EVALIDator tool or the Forest Inventory Data Online (FIDO) 

tool provide interactive access to the FIADB. 

The FIA Database 

The Forest Inventory and Analysis Database (FIADB) was developed to provide users with data in 

a consistent format, spanning all States and inventories. The first version of FIADB replaced two 

FIA regional databases; the Eastern States (Eastwide database) documented by Hansen and others 

(1992), and Western States (Westwide database) documented by Woudenberg and Farrenkopf 

(1995). A new national plot design (see chapter 2) provided the impetus for replacing these two 

databases, and FIA work units adopted the new design in all State inventories initiated after 1998. 

The FIADB table structure is currently derived from the National Information Management System 

(NIMS), which was designed to process and store annual inventory data. This is the fourth version 

of the single national FIA database to be released. A number of changes in the FIADB structure 

have been made to accommodate the data processing and storage requirements of NIMS. As a 

result, data from periodic inventories are stored in a format consistent with annual inventory data. 

FIADB files are available for periodic inventory data collected as early as 1977 (see appendix I). A 

wide variety of plot designs and regionally defined attributes were used in periodic inventories, 

often differing by State. Because of this, some data attributes may not be populated or certain data 

may have been collected or computed differently. During some periodic inventories, ground plot 

data were collected on nonreserved timberland only. Low productivity forest land, reserved (areas 

reserved from timber harvesting), and nonforested areas usually were not ground sampled. To 

account for the total area of a State, “place holder” plots were created to represent these nonsampled 

areas, which are identified by plot design code 999 in FIADB (PLOT.DESIGNCD = 999). For these 

plots, many attributes that are normally populated for forested plots will be blank. Users should be 

aware that while place holder plots account for the area of nonsampled forest land, they do not 

account for the corresponding forest attributes (such as volume, growth, or mortality) that may exist 

in those areas. 

Annual inventories, initiated sometime after 1999 depending on the State, use a nationally 

standardized plot design and common data collection procedures resulting in greater consistency 

among FIA work units than earlier inventories. However, as part of a continuing effort to improve 

the inventory, some changes in methodology and attribute definitions have been implemented after 

the new design was put into practice. Beginning in 1998, FIA started using a National Field Guide 

referenced as Field Guide 1.0. The database contains an attribute labeled MANUAL that stores the 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

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4 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

version number of the field guide under which the data were collected. When both the plot design is 

coded as being the national design (PLOT.DESIGNCD = 1) and the field guide is coded with a 

number greater than or equal to 1, certain attributes are defined as being “core” while others are 

allowed to be “core optional.” Core attributes must be collected by every FIA work unit, using the 

same definition and set of codes. In contrast, collection of core optional attributes are decided upon 

by individual FIA work units, using the same national protocol, predefined definition, and set of 

codes. Many attributes, regardless of whether or not they are core or core optional, are only 

populated for forested conditions, and are blank for other conditions (such as nonforest or water). 

Attributes described in chapter 3 are noted if they are core optional. 

Users who wish to analyze data using aggregations of multiple State inventories or multiple 

inventories within States should become familiar with changes in methodology and attribute 

definitions (see chapters 2 and 3). For each attribute in the current version of FIADB, an effort has 

been made to provide the current definition of the attribute, as well as any variations in definition 

that may have been used among various FIA work units. In other words, although inventory data 

have been made available in a common data format, users should be aware of differences that might 

affect their analyses. 

Changes From the Previous Database Version 

Database users should also be aware that changes are made for each version of FIADB. Sometimes 

the changes are minimal, such as simply rewriting explanatory text for clarification or adding new 

codes to a particular attribute. Database tables and/or attributes may be added or removed. In this 

release (4.0), a number of reference tables have been added. Also, two tables were added to modify 

the way population estimates are handled. Another important table addition is the Subplot 

Condition Change Matrix table that tracks changes in any condition class attribute between two 

visits to a plot. In appendix F, several changes were made in the SPGRPCD column. Tables 1-5 

summarize the major modifications to FIADB Version 4.0. 

Table 1. Database entire tables added in FIADB V4.0 

Name of table added Table description 

 SUBP_COND_CHNG_MTRX Subplot Condition Change Matrix 

 TREE_REGIONAL_BIOMASS Tree Regional Biomass 

 POP_EVAL_TYP Population Evaluation Type 

 REF_POP_EVAL_TYP_DESCR Reference Population Evaluation Type Description 

 REF_FOREST_TYPE Reference Forest Type 

 REF_SPECIES Reference Species 

 REF_SPECIES_GROUP Reference Species Group 

 REF_HABTYP_DESCRIPTION Reference Habitat Type Description 

 REF_HABTYP_PUBLICATION Reference Habitat Type Publication 

 REF_CITATION Reference Citation 

 REF_FIADB_VERSION Reference Forest Inventory and Analysis Database Version 

 REF_STATE_ELEV Reference State Elevation 

 REF_UNIT Reference Unit 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 5

Table 2. Database table attribute additions in FIADB V4.0 

Name of table affected Name of column added to table 

SURVEY RSCD 

SURVEY ANN_INVENTORY 

PLOT INTENSITY 

PLOT NF_SAMPLING_STATUS_CD 

PLOT NF_PLOT_STATUS_CD 

PLOT NF_PLOT_NONSAMPLE_REASN_CD 

PLOT P2VEG_SAMPLING_STATUS_CD 

PLOT P2VEG_SAMPLING_LEVEL_DETAIL_CD 

PLOT INVASIVE_SAMPLING_STATUS_CD 

PLOT INVASIVE_SPECIMEN_RULE_CD 

COND CARBON_DOWN_DEAD 

COND CARBON_LITTER 

COND CARBON_SOIL_ORG 

COND CARBON_STANDING_DEAD 

COND CARBON_UNDERSTORY_AG 

COND CARBON_UNDERSTORY_BG 

COND HARVEST_TYPE1_SRS 

COND HARVEST_TYPE2_SRS 

COND HARVEST_TYPE3_SRS 

COND NF_COND_STATUS_CD 

COND NF_COND_NONSAMPLE_REASN_CD 

COND CANOPY_CVR_SAMPLE_METHOD_CD 

COND LIVE_CANOPY_CVR_PCT 

COND LIVE_MISSING_CANOPY_CVR_PCT 

COND NBR_LIVE_STEMS 

SUBPLOT NF_SUBP_STATUS_CD 

SUBPLOT NF_SUBP_NONSAMPLE_REASN_CD 

SUBPLOT P2VEG_SUBP_STATUS_CD 

SUBPLOT P2VEG_SUBP_NONSAMPLE_REASN_CD 

SUBPLOT INVASIVE_SUBP_STATUS_CD 

SUBPLOT INVASIVE_NONSAMPLE_REASN_CD 

TREE DRYBIO_BOLE 

TREE DRYBIO_TOP 

TREE DRYBIO_STUMP 

TREE DRYBIO_SAPLING 

TREE DRYBIO_WDLD_SPP 

TREE DRYBIO_BG 

TREE CARBON_AG 

TREE CARBON_BG 

TREE PREV_PNTN_SRS 

POP_ESTN_UNIT P1SOURCE 
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6 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Name of table affected Name of column added to table 

POP_EVAL START_INVYR 

POP_EVAL END_INVYR 

POP_EVAL_ATTRIBUTE CN 

POP_EVAL_ATTRIBUTE STATECD 

POP_EVAL_GRP NOTES 

REF_POP_ATTRIBUTE CN 

REF_POP_ATTRIBUTE FOOTNOTE 

Table 3. Database table attribute deletions in FIADB V4.0 

Name of table affected Name of column deleted 

PLOT CREW_TYPE 

PLOT MANUAL_DB 

PLOT REPLACED_PLOT_NBR 

PLOT LAST_INVYR_MEASURED 

COND TRTOPCD 

COND PASTNFCD 

COND DISTANCE_WATER_SRS 

TREE PREVSUBC 

SITETREE SITREE_EQU_NO_PNWRS 

Table 4. Database table attributes renamed in FIADB V4.0 

Name of table affected Old attribute name New attribute name 

PLOT GROWCD GROW_TYP_CD 

PLOT MORTCD MORT_TYP_CD 

COND TRTCD1_SRS HARVEST_TYPE1_SRS 

COND TRTCD2_SRS HARVEST_TYPE2_SRS 

COND TRTCD3_SRS HARVEST_TYPE3_SRS 

SUBPLOT STATUSCD SUBP_STATUS_CD 

SITETREE COND_CLASS_LIST CONDLIST 

Table 5. Database table attributes moved to another table in FIADB V4.0 

Original table New table Column moved and renamed 

TREE TREE_REGIONAL_BIOMASS REGIONAL_DRYBIOT 

TREE TREE_REGIONAL_BIOMASS REGIONAL_DRYBIOM 

A change was made in the stocking equation assignment for various tree species and was applied to 

all annual inventory plot data. This change can result in a different computed forest type for a given 

plot. Several new forest types have been added and some changes were made in the way forest 

types are grouped. 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 7

Another significant change relates to biomass and carbon. FIA adopted a standard methodology to 

compute biomass of various tree components, which are used to convert biomass to carbon 

estimates. Previous biomass estimates, which were derived using a variety of equations, have been 

moved to a new table called TREE_REGIONAL_BIOMASS. Users can choose which attribute to 

summarize and can make comparisons between the estimates derived from the different 

methodologies. 

Modeled condition level carbon attributes have been added to the FIADB and can be used to obtain 

results similar to those found in the U.S. Environmental Protection Agency’s (EPA’s) Greenhouse 

Gas Inventory (http://epa.gov/climatechange/emissions/). 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 2 

8 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Chapter 2 -- FIA Sampling and Estimation Procedures 

To use the FIADB effectively, users should acquire a basic understanding of FIA sampling and 

estimation procedures. Generally described, FIA uses what may be characterized as a three-phase 

sampling scheme. Phase 1 (P1) is used for stratification, while Phase 2 (P2) consists of plots that are 

visited or photo-interpreted. A subset of Phase 2 plots are designated as Phase 3 (P3) plots 

(formerly known as Forest Health Monitoring (FHM) plots) where additional health indicator 

attributes are collected. Phases 1 and 2 are described in this chapter, but Phase 3 is described in a 

separate user’s manual (Woodall and others 2010). The exception is P3 crown attributes, which are 

described in the TREE table of this document. 

Sampling and Stratification Methodology 

Remote Sensing (P1)

The basic level of inventory in the FIA program is the State, which begins with the interpretation of 

a remotely sensed sample, referred to as Phase 1 (P1). The intent of P1 is to classify the land into 

various remote sensing classes for the purpose of developing meaningful strata. A stratum is a 

group of plots that have the same or similar remote sensing classifications. Stratification is a 

statistical technique used by FIA to aggregate Phase 2 ground samples into groups to reduce 

variance when stratified estimation methods are used. The total area of the estimation unit is 

assumed to be known. 

Each Phase 2 ground plot is assigned to a stratum and the weight of the stratum is based on the 

proportion of the stratum within the estimation unit. Estimates of population totals are then based 

on the sum of the product of the known total area, the stratum weight, and the mean of the plot level 

attribute of interest for each stratum. The expansion factor for each stratum within the estimation 

unit is the product of the known total area and the stratum weight divided by the number of Phase 2 

plots in the stratum. 

Selection criteria for remote sensing classes and computation of area expansion factors differ from 

State to State. Users interested in the details of how these expansion factors are assigned to ground 

plots for a particular State should contact the appropriate FIA work unit (see table 6). 

Ground Sampling (P2) 

FIA ground plots, or Phase 2 plots, are designed to cover a 1-acre sample area; however, not all 

trees on the acre are measured. Ground plots may be new plots that have never been measured, or 

re-measurement plots that were measured during one or more previous inventories. Recent 

inventories use a nationally standard, fixed-radius plot layout for sample tree selection (see figure 2). 

Various arrangements of fixed-radius and variable-radius (prism) subplots were used to select 

sample trees in older inventories. 

Plot Location 

The FIADB includes coordinates for every plot location in the database, whether it is forested or 

not, but these are not the precise locations of the plot centers. In an amendment to the Food Security 

Act of 1985 (reference 7 USC 2276 § 1770), Congress directed FIA to ensure the privacy of private 

landowners. Exact plot coordinates could be used in conjunction with other publicly available data 

to link plot data to specific landowners, in violation of requirements set by Congress. In addition to 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 9

the issue of private landowner privacy, the FIA program had concerns about plot integrity and 

vandalism of plot locations on public lands. A revised policy has been implemented and methods 

for making approximate coordinates available for all plots have been developed. These methods are 

collectively known as “fuzzing and swapping” (Lister and others 2005). 

In the past, FIA provided approximate coordinates for its periodic data in the FIADB. These 

coordinates were within 1.0 mile of the exact plot location (this is called fuzzing). However, 

because some private individuals own extensive amounts of land in certain counties, the data could 

still be linked to these owners. In order to maintain the privacy requirements specified in the 

amendments to the Food Security Act of 1985, up to 20 percent of the private plot coordinates are 

swapped with another similar private plot within the same county (this is called swapping). This 

method creates sufficient uncertainty at the scale of the individual landowner such that privacy 

requirements are met. It also ensures that county summaries and any breakdowns by categories, 

such as ownership class, will be the same as when using the true plot locations. This is because only 

the coordinates of the plot are swapped – all the other plot characteristics remain the same. The only 

difference will occur when users want to subdivide a county using a polygon. Even then, results 

will be similar because swapped plots are chosen to be similar based on attributes such as forest 

type, stand-size class, latitude, and longitude (each FIA work unit has chosen its own attributes for 

defining similarity). 

For plot data collected under the current plot design, plot numbers are reassigned to sever the link to 

other coordinates stored in the FIADB prior to the change in the law. Private plots are also swapped 

using the method described above; remeasured plots are swapped independent of the periodic data. 

All plot coordinates are fuzzed, but less than before – within 0.5 mile for most plots and up to 1.0 

mile on a small subset of them. This was done to make it difficult to locate the plot on the ground, 

while maintaining a good correlation between the plot data and map-based characteristics. 

Figure 2. The FIA mapped plot design. Subplot 1 is the center 

of the cluster with subplots 2, 3, and 4 located 120 feet away 

at azimuths of 360°, 120°, and 240°, respectively. 
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10 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

For most user applications, such as woodbasket analyses and estimates of other large areas, fuzzed 

and swapped coordinates provide a sufficient level of accuracy. However, some FIA customers 

require more precision of plot locations in order to perform analyses by user-defined polygons and 

for relating FIA plot data to other map-based information, such as soils maps and satellite imagery. 

In order to accommodate this need, FIA provides spatial data services that allow most of the desired 

analyses while meeting privacy requirements. The possibilities and limitations for these types of 

analyses are case-specific, so interested users should contact their local FIA work unit for more 

information. 

Plot Design, Condition Delineation, and Types of Data Attributes 

Plot Designs 

The current national standard FIA plot design was originally developed for the Forest Health 

Monitoring program (Scott and others 1993). It was adopted by FIA in the mid-1990s and used for 

the last few periodic inventories and all annual inventories. The standard plot consists of four 24.0-

foot radius subplots (approximately 0.0415 or 1/24 acre) (see figure 2), on which trees 5.0 inches 

and greater in diameter are measured. Within each of these subplots is nested a 6.8-foot radius 

microplot (approximately 1/300th acre) on which trees smaller than 5.0 inches in diameter are 

measured. A core optional variant of the standard design includes four “macroplots,” each with a 

radius of 58.9 feet (approximately 1/4 acre) that originate at the centers of the 24.0-foot radius 

subplots. Breakpoint diameters between the 24-foot radius subplots and the macroplots vary and are 

specified in the macroplot breakpoint diameter attribute (PLOT.MACRO_BREAKPOINT_DIA). 

Prior to adoption of the current plot design, a wide variety of plot designs were used. Periodic 

inventories might include a mixture of designs, based on forest type, ownership, or time of plot 

measurement. In addition, similar plot designs (e.g., 20 BAF variable-radius plots) might have been 

used with different minimum diameter specifications (e.g., 1-inch versus 5-inch). Details on these 

designs are included in appendix B (plot design codes). 

Conditions 

An important distinguishing feature between the current plot design and previous designs is that 

different conditions are “mapped” on the current design (see figure 3). In older plot designs, 

adjustments were made to the location of the plot center or the subplots were rearranged such that 

the entire plot sampled a single condition. In the new design, the plot location and orientation 

remains fixed, but boundaries between conditions are mapped and recorded. Conditions are defined 

by changes in land use or changes in vegetation that occur along more-or-less distinct boundaries. 

Reserved status, owner group, forest type, stand-size class, regeneration status, and stand density 

are used to define forest conditions. For example, the subplots may cover forest and nonforest areas, 

or it may cover a single forested area that can be partitioned into two or more distinct stands. 

Although mapping is used to separate forest and nonforest conditions, different nonforest conditions 

occurring on a plot are not mapped during initial plot establishment. Each condition occurring on 

the plot is assigned a condition proportion, and all conditions on a plot add up to 1.0. For plot 

designs other than the mapped design, condition proportion is always equal to 1.0 in FIADB. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 11

Types of Attributes 

Measured, Assigned, and Computed Attributes 

In addition to attributes that are collected in the field, FIADB includes attributes that are populated 

in the office. Examples of field attributes include tree diameter and height, and slope and aspect of 

the plot and subplot. Attributes that are populated in the office include assigned attributes, such as 

county and owner group codes, or computed attributes, such as tree and area expansion factors, and 

tree volumes. 

For measured attributes, this document provides only basic information on the methodology used in 

the field. The authoritative source for methodology is the Forest Inventory and Analysis National 

Core Field Guide used during the inventory in which the data were collected (see 

http://www.fia.fs.fed.us/library/field-guides-methods-proc/) . The MANUAL attribute in the PLOT 

table documents the version number where data collection protocols can be found. 

Values of attributes that are assigned in the office are determined in several ways, depending on the 

attribute. For example, ownership may be determined using geographic data or local government 

records. Other attributes, such as Congressional District and Ecological Subsection are assigned 

values based on data management needs. 

Some computed attributes in the database are derived using other attributes in the database. 

Ordinarily, such attributes would not be included in a database table because they could be 

Figure 3. The FIA mapped plot design. Subplot 1 is 

the center of the cluster with subplots 2, 3, and 4 

located 120 feet away at azimuths of 360°, 120°, and 

240°, respectively. When a plot straddles two or more 

conditions, the plot area is divided by condition. 

Condition 3 Condition 1 Condition 2 
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12 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

computed using the supplied attributes. However, some data compilation routines are complex or 

vary within or among FIA work units, so these computed attributes are populated for the 

convenience of database users. 

One example of a computed attribute is site index, which is computed at the condition level. Site 

index is generally a function of height and age, although other attributes may be used in 

conjunction. In addition, several different site index equations may be available for a species within 

its range. Height and age data are included in the TREE table, but only certain trees (see SITETREE 

table) are included in the site index attribute that is reported for the condition. As a result, it would 

be time-consuming for users to replicate the process required to calculate site index at the condition 

level. For convenience, the condition (COND) table includes site index (SICOND), the species for 

which it is calculated (SISP), and the site index base age (SIBASE). 

In most cases computed attributes should be sufficient for users’ needs, because the equations and 

algorithms used to compute them have been determined by the FIA program to be the best available 

for the plot location. However, for most computed attributes the relevant tree and plot level 

attributes used to compute them are included in the database, so users may do their own calculations 

if desired. 

Regional Attributes 

A number of regionally specific attributes are available in FIADB. These regional attributes are 

identified by FIA work unit, both in the table structure description (e.g., the attribute is named with 

an extension such as NERS) and in the attribute description (e.g., the attribute description text 

contains the phrase “Only collected by...”). For specific questions about the data from a particular 

FIA work unit, please contact the individuals listed in table 6. 

Table 6. Contacts at individual FIA work units 

 FIA Work Unit RSCD States 

Database 

Contact Phone

Analyst 

Contact Phone 

 Rocky Mountain 

 (RMRS) 22 

AZ,CO,ID,MT,NV, 

NM,UT,WY Mark Rubey 801-625-5647 John Shaw 801-625-5673

 North Central 

 (NCRS)* 23 

IL,IN,IA,KS,MI,MN,

MO,NE,ND,SD,WI Carol Alerich 610-557-4068 

Will 

McWilliams 610-557-4050

 

 Northeastern 

(NERS)* 24 

CT,DE,ME,MD,MA,

NH,NJ,NY,OH,PA, 

RI, VT,WV Carol Alerich 610-557-4068 

Will 

McWilliams 610-557-4050

 Pacific Northwest 

 (PNWRS) 26,27 AK,CA,HI,OR,WA Ron Wanek 503-808-2048 

Karen 

Waddell 503-808-2046

 Southern (SRS) 33 

AL,AR,FL,GA,KY, 

LA,MS,NC,OK,SC, 

TN,TX,VA, PR, VI Jeff Turner 865-862-2053 Tom Brandeis 865-862-2030

*The North Central Research Station (NCRS) and the Northeastern Research Station (NERS) have merged to become 

one research station, the Northern Research Station. The former regional designations are kept to accommodate the 

data. 

More information on attribute types is included in chapter 3. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 13

Expansion Factors 

Tree Expansion Factors 

The expansion factor(s) used to scale each tree on a plot to a per-acre basis is dependent on the plot 

design. For fixed-plot designs, scaling is straightforward, with the number of trees per acre (TPA) 

represented by one tree equal to the inverse of the plot area in acres. The general formula is shown 

by equation [1]: 

[1] TPA = 1/(N*A) 

 Where N is the number of subplots, and 

 A is the area of each subplot. 

For example, the TPA of each tree ≥5.0 inches in diameter occurring on the current plot design 

would be calculated using equation [2]: 

[2] TPA = 1/(4*0.04154172) = 6.018046 

This expansion factor can be found in the TPA_UNADJ attribute in the TREE table (see chapter 3) 

for plots measured with the annual plot design. In variable-radius plot designs, the per-acre 

expansion factor is determined by the diameter of the tree, the basal area factor (BAF), and the 

number of subplots used in the plot design. The general formula is shown by equation [3]: 

[3] TPA = (BAF / 0.005454*DIA2 )/N 

 Where BAF is the variable-radius basal area factor in square feet, 

 DIA is diameter of the tally tree in inches, and 

 N is the number of subplots in the plot design. 

For example, if a 11.5-inch tree is tallied using a 10 BAF prism on a variable-radius design plot that 

uses five subplots, the calculation is: 

[4] TPA = (10 / 0.005454*11.52 )/5 = 2.773 

A 5.2-inch tree will have a greater expansion factor: 

[5] TPA = (10 / 0.005454*5.22 )/5 = 13.562 

Although it is not necessary to calculate expansion factors for different plot designs because they 

are stored in TPA_UNADJ, information on plot design can be found by using the code from the 

DESIGNCD attribute in the PLOT table to look up the plot design specifications in appendix B. 

Plot Area Expansion Factors 

Some previous versions of FIADB have included area expansion factors in the PLOT table that 

were used to scale plot-level data to population-level estimates (see EXPCURR and related 

attributes in Miles and others 2001). In this version of FIADB, area expansion factors have been 

removed from the PLOT table. Instead, there is one area expansion factor (EXPNS) stored in the 

POP_STRATUM table. This change is needed because of the way annual inventory data are 

compiled. Under the annual inventory system, new plots are added each year. Adjustment factors 

that are used to compensate for denied access, inaccessible, and other reasons for not sampling may 
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14 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

differ each time new data replaces older data. Both the number of acres each plot represents and the 

adjustments for the proportion of plots not sampled may change each year. In order to allow users to 

obtain population estimates for any grouping of data, an adjustment factor has been calculated and 

stored for each set of data being compiled. There is a separate adjustment factor for each fixed plot 

size: microplot, subplot, and macroplot. These attributes are also stored in the POP_STRATUM 

table. Each time the data are stratified differently, the adjustments and expansion factor may 

change. Therefore, FIA provides a different expansion factor every time the data are restratified. 

FIA has chosen the term ‘evaluation’ to describe this process of storing different stratifications of 

data either for an individual set of data or for the changing sets of data through time. Each 

aggregation of data is given an evaluation identifier (EVALID). The user can select population 

estimates for the most current set of data or for previous sets of data. In addition to being able to 

calculate population estimates, users can now calculate sampling error information because FIA is 

storing all of the Phase 1 information used for the stratification. That information is stored for each 

estimation unit, which is usually a geographic subset of the State (see the POP_ESTN_UNIT table). 

For more information about evaluations and calculation of area expansion factors, see chapter 4. 

A different method of population estimation is being implemented in this version of FIADB. In 

FIADB 3.0, users would select the appropriate evaluation sequence number (EVAL_CN_FOR_xxx) 

from the POP_EVAL_GRP table. This evaluation sequence number allowed them to select the 

appropriate plots and associated expansions. The newly added POP_EVAL_TYP table allows users 

to perform the similar queries, retrieving the same information, and will allow for a variety of 

evaluations to be added in the future. The previous method will continue to work in version 4.0. 

Accuracy Standards 

Forest inventory plans are designed to meet sampling error standards for area, volume, growth, and 

removals provided in the Forest Service directive (FSH 4809.11) known as the Forest Survey 

Handbook (U.S. Department of Agriculture 2008). These standards, along with other guidelines, are 

aimed at obtaining comprehensive and comparable information on timber resources for all parts of 

the country. FIA inventories are commonly designed to meet the specified sampling errors at the 

State level at the 67 percent confidence limit (one standard error). The Forest Survey Handbook 

mandates that the sampling error for area cannot exceed 3 percent error per 1 million acres of 

timberland. A 5 percent (Eastern United States) or 10 percent (Western United States) error per 1 

billion cubic feet of growing-stock on timberland is applied to volume, removals, and net annual 

growth. Unlike the mandated sampling error for area, sampling errors for volume, removals, and 

growth are only targets. 

FIA inventories are extensive inventories that provide reliable estimates for large areas. As data are 

subdivided into smaller and smaller areas, such as a geographic unit or a county, the sampling 

errors increase and the reliability of the estimates goes down. 

• A State with 5 million acres of timberland would have a maximum allowable sampling error of 

1.3 percent (3% x (1,000,000)0.5 / (5,000,000)0.5). 

• A geographic unit within that State with 1 million acres of timberland would have a 3.0 percent 

maximum allowable sampling error (3% x (1,000,000)0.5 / (1,000,000)0.5). 

• A county within that State with 100 thousand acres would have a 9.5 percent maximum 

allowable sampling error (3% x (1,000,000)0.5 / (100,000)0.5) at the 67 percent confidence level. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 15

The greater allowance for sampling error in smaller areas reflects the decrease in sample size as 

estimation area decreases. 

Estimation procedures and the calculation of confidence intervals for typical FIA tables are 

discussed in chapter 4. Additional information on estimation and confidence intervals can be found 

in Bechtold and Patterson (2005). 
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16 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Chapter 3 -- Database Structure 

This chapter provides information about the database tables, including detailed descriptions of all 

attributes within the tables. Each column or attribute in a table is listed with its unabbreviated name, 

followed by a description of the attribute. Attributes that are coded include a list of the codes and 

their meanings. Appendix A is an index of the attributes, sorted alphabetically by column name, 

showing the table where the column is found including the attribute number in the table. Some 

overview information is presented below, followed by a section with complete information about all 

tables and attributes. 

Table Descriptions 

There are nineteen data tables and eleven reference tables in the Phase 1 and Phase 2 portions of the 

FIA Database. 

• SURVEY table – Contains one record for each year an inventory is conducted in a State for 

annual inventory or one record for each periodic inventory. 

o SURVEY.CN = PLOT.SRV_CN links the unique inventory record for a State and year 

to the plot records. 

• COUNTY table – Reference table for the county codes and names. This table also includes 

survey unit codes. 

o COUNTY.CN = PLOT.CTY_CN links the unique county record to the plot record. 

• PLOT table – Provides information relevant to the entire 1-acre field plot. This table links to 

most other tables, and the linkage is made using PLOT.CN = TABLE_NAME.PLT_CN 

(TABLE_NAME is the name of any table containing the column name PLT_CN). Below are 

some examples of linking PLOT to other tables. 

o PLOT.CN = COND.PLT_CN links the unique plot record to the condition class 

record(s). 

o PLOT.CN = SUBPLOT.PLT_CN links the unique plot record to the subplot records. 

o PLOT.CN = TREE.PLT_CN links the unique plot record to the tree records. 

o PLOT.CN = SEEDLING.PLT_CN links the unique plot record to the seedling records. 

• COND table – Provides information on the discrete combination of landscape attributes that 

define the condition (a condition will have the same land class, reserved status, owner 

group, forest type, stand-size class, regeneration status, and stand density). 

o PLOT.CN = COND.PLT_CN links the condition class record (s) to the plot table. 

o COND.PLT_CN = SITETREE.PLT_CN and COND.CONDID = SITETREE.CONDID 

links the condition class record to the site tree data. 

o COND.PLT_CN = TREE.PLT_CN and COND.CONDID = TREE.CONDID links the 

condition class record to the tree data. 

• SUBPLOT table – Describes the features of a single subplot. There are multiple subplots per 

1-acre field plot and there can be multiple conditions sampled on each subplot. 

o PLOT.CN = SUBPLOT.PLT_CN links the unique plot record to the subplot records. 

o SUBPLOT.PLT_CN = COND.PLT_CN and SUBPLOT.MACRCOND = 

COND.CONDID links the macroplot conditions to the condition class record. 

o SUBPLOT.PLT_CN = COND.PLT_CN and SUBPLOT.SUBPCOND = 

COND.CONDID links the subplot conditions to the condition class record. 

o SUBPLOT.PLT_CN = COND.PLT_CN and SUBPLOT.MICRCOND = 

COND.CONDID links the microplot conditions to the condition class record. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 17

• SUBP_COND table – Contains information about the proportion of a subplot in a condition. 

o PLOT.CN = SUBP_COND.PLT_CN links the subplot condition class record to the plot 

table. 

o SUBP_COND.PLT_CN = COND.PLT_CN and SUBP_COND.CONDID = 

COND.CONDID links the condition class records found on the four subplots to the 

subplot description. 

• TREE table – Provides information for each tree 1 inch in diameter and larger found on a 

microplot, subplot, or core optional macroplot. 

o PLOT.CN = TREE.PLT_CN links the tree records to the unique plot record. 

o COND.PLT_CN = TREE.PLT_CN and COND.CONDID = TREE.CONDID links the 

tree records to the unique condition record. 

• SEEDLING table – Provides a count of the number of live trees of a species found on a 

microplot that are less than 1 inch in diameter but at least 6 inches in length for conifer 

species or at least 12 inches in length for hardwood species. 

o PLOT.CN = SEEDLING.PLT_CN links the seedling records to the unique plot record. 

• SITETREE table – Provides information on the site tree(s) collected in order to calculate 

site index and/or site productivity information for a condition. 

o PLOT.CN = SITETREE.PLT_CN links the site tree records to the unique plot record. 

o SITETREE.PLT_CN = COND.PLT_CN and SITETREE.CONDID = COND.CONDID 

links the site tree record(s)to the unique condition class record. 

• BOUNDARY table – Provides a description of the demarcation line between two conditions 

that occur on a single subplot. 

o PLOT.CN = BOUNDARY.PLT_CN links the boundary records to the unique plot 

record. 

• SUBP_COND_CHNG_MTRX table – Contains information about the mix of current and 

previous conditions that occupy the same area on the subplot. 

o PLOT.CN = SUBP_COND_CHNG_MTRX.PLT_CN links the subplot condition change 

matrix records to the unique plot record. 

o PLOT.PREV_PLOT_CN = SUBP_COND_CHNG_MTRX.PREV_PLT_CN links the 

subplot condition change matrix records to the unique previous plot record. 

• TREE_REGIONAL_BIOMASS table – Contains biomass estimates computed using 

equations and methodology that varies by FIA work unit. This table retains valuable 

information for generating biomass estimates that match earlier published reports. 

o TREE.CN = TREE_REGIONAL_BIOMASS.TRE_CN links a tree regional biomass 

record to the corresponding unique tree. 

• POP_ESTN_UNIT table – An estimation unit is a geographic area that can be drawn on a 

map. It has known area and the sampling intensity must be the same within a stratum within 

an estimation unit. Generally estimation units are contiguous areas, but exceptions are made 

when certain ownerships, usually National Forests, are sampled at different intensities. One 

record in the POP_ESTN_UNIT table corresponds to a single estimation unit. 

o POP_ESTN_UNIT.CN = POP_STRATUM.ESTN_UNIT_CN links the unique stratified 

geographical area (ESTN_UNIT) to the strata (STRATUMCD) that are assigned to each 

ESTN_UNIT. 

• POP_EVAL table – An evaluation is the combination of a set of plots (the sample) and a set 

of Phase 1 data (obtained through remote sensing, called a stratification) that can be used to 

produce population estimates for a State (an evaluation may be created to produce 

population estimates for a region other than a State, such as the Black Hills National Forest). 
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18 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

A record in the POP_EVAL table identifies one evaluation and provides some descriptive 

information about how the evaluation may be used. 

o POP_ESTN_UNIT.EVAL_CN = POP_EVAL.CN links the unique evaluation identifier 

(EVALID) in the POP_EVAL table to the unique geographical areas (ESTN_UNIT) that 

are stratified. Within a population evaluation (EVALID) there can be multiple 

population estimation units, or geographic areas across which there are a number of 

values being estimated (e.g., estimation of volume across counties for a given State.) 

• POP_EVAL_ATTRIBUTE table – Provides information as to which population estimates 

can be provided by an evaluation. If an evaluation can produce 22 of the 92 currently 

supported population estimates, there will be 22 records in the POP_EVAL_ATTRIBUTE 

table (one per population estimate) for that evaluation. 

o POP_EVAL.CN = POP_EVAL_ATTRIBUTE.EVAL_CN links the unique evaluation 

identifier to the list of population estimates that can be derived for that evaluation. 

• POP_EVAL_GRP table – Provides information on the suite of evaluations that were used to 

generate a complete set of reports for an inventory. In a typical State inventory report, one 

evaluation is used to generate an estimate of the total land area; a second evaluation is used 

to generate current estimates of volume, numbers of trees and biomass; and a third 

evaluation is used for estimating growth, removals and mortality. One record in the 

POP_EVAL_GRP record identifies all the evaluations that were used in generating 

estimates for a State inventory report. Each record in the POP_EVAL table corresponds to 

an EVAL_CN_FOR_XX column in the POP_EVAL_GRP table, (XX is one of the 

following: Expall, Expcurr, Expvol, Expgrow, Expmort, or Expremv). Similar information 

is contained in the POP_EVAL_TYP table, which has been added to this version of the 

database. 

o POP_EVAL_TYP.EVAL_GRP_CN = POP_EVAL_GRP.CN links the evaluation type 

record to the evaluation group record. 

o POP_EVAL.CN = POP_EVAL_GRP.EVAL_CN_FOR_EXPALL links the evaluation 

for all land to the evaluation identifier that includes all plots used to make the estimate. 

o POP_EVAL.CN = POP_EVAL_GRP.EVAL_CN_FOR_EXPCURR links the evaluation 

for sampled land to the evaluation identifier that includes all sampled plots used to make 

the estimate. 

o POP_EVAL.CN = POP_EVAL_GRP.EVAL_CN_FOR_EXPVOL links the evaluation 

for tree volume, biomass, or number of trees to the evaluation identifier that includes all 

plots used to make these estimates. 

o POP_EVAL.CN = POP_EVAL_GRP.EVAL_CN_FOR_EXPGROW links the 

evaluation for average annual tree growth to the evaluation identifier that includes all 

remeasured plots used to make the estimate. 

o POP_EVAL.CN = POP_EVAL_GRP.EVAL_CN_FOR_EXPMORT links the 

evaluation for average annual tree mortality to the evaluation identifier that includes all 

remeasured plots used to make the estimate. 

o POP_EVAL.CN = POP_EVAL_GRP.EVAL_CN_FOR_EXPREMV links the 

evaluation for average annual tree removals to the evaluation identifier that includes all 

remeasured plots used to make the estimate. 

• POP_EVAL_TYP table – Provides information on the type of evaluations that were used to 

generate a set of tables for an inventory report. In a typical State inventory report, one 

evaluation is used to generate an estimate of the total land area; a second evaluation is used 

to generate current estimates of volume, numbers of trees and biomass; and a third 

evaluation is used for estimating growth, removals and mortality. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 19

o POP_EVAL_TYP.EVAL_CN = POP_EVAL.CN links the evaluation type record to the 

evaluation record. 

o POP_EVAL_TYP.EVAL_GRP_CN = POP_EVAL_GRP.CN links the evaluation type 

record to the evaluation group record. 

o POP_EVAL_TYP.EVAL_TYP = REF_POP_EVAL_TYP_DESCR.EVAL_TYP links 

an evaluation type record to an evaluation type description reference record. 

• POP_PLOT_STRATUM_ASSGN table – Stratum information is assigned to a plot by 

overlaying the plot’s location on the Phase 1 imagery. Plots are linked to their appropriate 

stratum for an evaluation via the POP_PLOT_STRATUM_ASSGN table. 

o POP_PLOT_STRATUM_ASSGN.PLT_CN = PLOT.CN links the stratum assigned to 

the plot record. 

• POP_STRATUM table – The area within an estimation unit is divided into strata. The area 

for each stratum can be calculated by determining the proportion of Phase 1 pixels/plots in 

each stratum and multiplying that proportion by the total area in the estimation unit. 

Information for a single stratum is stored in a single record of the POP_STRATUM table. 

o POP_STRATUM.CN = POP_PLOT_STRATUM_ASSGN.STRATUM_CN links the 

defined stratum to each plot. 

• REF_CITATION table – Identifies the published source for information on specific 

gravities, moisture content, and bark as a percent of wood volume that is provided in the 

REF_SPECIES table. 

o REF_SPECIES.WOOD_SPGR_GREENVOL_DRYWT_CIT = 

REF_CITATION.CITATION_NBR 

o REF_SPECIES.BARK_SPGR_GREENVOL_DRYWT_CIT = 

REF_CITATION.CITATION_NBR 

o REF_SPECIES.MC_PCT_GREEN_WOOD_CIT = 

REF_CITATION.CITATION_NBR 

o REF_SPECIES.MC_PCT_GREEN_BARK_CIT = 

REF_CITATION.CITATION_NBR 

o REF_SPECIES.WOOD_SPGR_MC12VOL_DRYWT_CIT = 

REF_CITATION.CITATION_NBR 

o REF_SPECIES.BARK_VOL_PCT_CIT = REF_CITATION.CITATION_NBR 

• REF_FIADB_VERSION table – Contains information identifying the format of the 

currently available FIADB. 

• REF_FOREST_TYPE table – A reference table containing forest type codes, descriptive 

names, forest type group codes and other information. Data users should link codes as 

shown below and then obtain the information stored in MEANING to convert the code to a 

name. 

o REF_FOREST_TYPE.VALUE = COND.FORTYPCD links the forest type reference 

record to the condition forest code used for reporting and analysis purposes. 

o REF_FOREST_TYPE.VALUE = COND.FLDTYPCD links the forest type reference 

record to the condition forest type code recorded by field crews. 

o REF_FOREST_TYPE.VALUE = COND.FORTYPCDCALC links the forest type 

reference record to the condition forest type code calculated by an algorithm. 

• REF_POP_ATTRIBUTE table – Identifies all of the population estimates that are currently 

supported, and provides information useful to the estimation procedure. There are currently 

92 records in the REF_POP_ATTRIBUTE table providing information ranging from how to 

calculate forest area to average annual net growth on forestland. 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3 

20 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

o REF_POP_ATTRIBUTE.ATTRIBUTE_NBR = 

POP_EVAL_ATTRIBUTE.ATTRIBUTE_NBR links the description of the unique 

population estimate to the records of evaluations that can be used to make those 

estimates. 

• REF_POP_EVAL_TYP_DESCR table – A reference table containing the description for 

each evaluation type. 

o REF_POP_EVAL_TYP_DESCR.EVAL_TYP = POP_EVAL_TYP.EVAL_TYP links 

an evaluation type description reference record to an evaluation type record. 

• REF_SPECIES table – A reference table containing the species code, descriptive common 

name, scientific name, and many other attributes for each species. For example, data users 

who want to convert the species code to the associated common name should link codes as 

shown below and then obtain the information stored in COMMON_NAME. 

o REF_SPECIES.SPCD = TREE.SPCD links the species reference table record to the tree 

species code. 

o REF_SPECIES.SPCD = SEEDLING.SPCD links the species reference table record to 

the seedling species code. 

o REF_SPECIES.SPCD = SITETREE.SPCD links the species reference table record to the 

site tree species code. 

• REF_SPECIES_GROUP table – A reference table containing the species group code, 

descriptive name, and several other attributes for each species group. Data users should link 

codes as shown below and then obtain the information stored in NAME to convert the code 

to a descriptive name. 

o REF_SPECIES_GROUP.SPGRPCD = TREE.SPGRPCD links the species group 

reference table to the tree species group code. 

o REF_SPECIES_GROUP.SPGRPCD = SEEDLING.SPGRPCD links the species 

reference table record to the seedling species group code. 

o REF_SPECIES_GROUP.SPGRPCD = SITETREE.SPGRPCD links the species 

reference table record to the site tree species group code. 

• REF_STATE_ELEV – Reference table containing information about minimum and 

maximum elevation found within a State. 

o REF_STATE_ELEV.STATECD = SURVEY.STATECD links the State elevation 

reference record to the survey record. 

• REF_UNIT table – The description for each survey unit in a State. 

o REF_UNIT.STATECD = PLOT.STATECD and REF_UNIT.VALUE = PLOT.UNITCD 

links the survey unit description (MEANING) to the PLOT record. 

Figure 4 helps to illustrate how the Phase 1 and other population estimation tables relate to one 

another and to the PLOT table. 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 21

Figure 4. Relationships among Phase 1 and population estimation tables to the Phase 2 

plot and other frequently used tables. 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3 

22 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Keys Presented with the Tables 

Each summarized table in chapter 3 has a list of keys just below the bottom of the table. These keys 

are used to join data from different tables. The following provides a general definition of each kind 

of key. 

Primary key 

A single column in a table whose values uniquely identify each row in an Oracle

1

table. The 

primary key in each FIADB 4.0 table is the CN column. 

The name of the primary key for each table is listed in the table description. It follows the 

nomenclature of ‘TABLEABBREVIATION’_PK. The table abbreviations are: 

Table name Table abbreviation 

SURVEY SRV 

COUNTY CTY 

PLOT PLT 

COND CND 

SUBPLOT SBP 

SUBP_COND SCD 

TREE TRE 

SEEDLING SDL 

SITETREE SIT 

BOUNDARY BND 

SUBP_COND_CHNG_MTRX CMX 

TREE_REGIONAL_BIOMASS TRB 

POP_ESTN_UNIT PEU 

POP_EVAL PEV 

POP_EVAL_ATTRIBUTE PEA 

POP_EVAL_GRP PEG 

POP_EVAL_TYP PET 

POP_PLOT_STRATUM_ASSGN PPSA 

POP_STRATUM PSM 

REF_POP_ATTRIBUTE PAE 

REF_POP_EVAL_TYP_DESCR PED 

REF_FOREST_TYPE RFT 

REF_SPECIES SPC 

REF_SPECIES_GROUP SPG 

REF_HABTYP_DESCRIPTION RHN 

REF_HABTYP_PUBLICATION RPN 

REF_CITATION CIT 

REF_FIADB_VERSION RFN 

REF_STATE_ELEV RSE 

REF_UNIT UNT 

 

1 The use of trade or firm names in this publication is for reader information only and does not imply endorsement by the U.S. 

Department of Agriculture of any product or service.
FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 23

Unique key 

Multiple columns in a table whose values uniquely identify each row in an Oracle table. 

There can be one and only one row for each unique key value. 

The unique key varies for each FIADB 4.0 table. The unique key for the PLOT table is 

STATECD, INVYR, UNITCD, COUNTYCD, and PLOT. The unique key for the COND 

table is PLT_CN and CONDID. 

The name of the unique key for each table is listed in the table description. It follows the 

nomenclature of ‘TABLEABBREVIATION’_UK. 

Natural key 

A type of unique key made from existing attributes in the table. It is stored as an index in 

this database. 

 

 Not all FIADB 4.0 tables have a natural key. For example, there is no natural key in the 

PLOT table, rather the natural key and the unique key are the same. The natural key for the 

COND table is STATECD, INVYR, UNITCD, COUNTYCD, PLOT, and CONDID. 

The name of the natural key for each table is listed in the table description. It follows the 

nomenclature of ‘TABLEABBREVIATION’_NAT_I. 

Foreign key 

A column in a table that is used as a link to a matching column in another Oracle table. 

A foreign key connects a record in one table to one and only one record in another table. 

Foreign keys are used both to link records between data tables and as a check (or constraint) 

to prevent “unrepresented data.” For example, if there are rows of data in the TREE table for 

a specific plot, there needs to be a corresponding data row for that same plot in the PLOT 

table. The foreign key in the TREE table is the attribute PLT_CN, which links specific rows 

in the TREE table to one record in the PLOT table using the plot attribute CN. 

The foreign key for the COND table is PLT_CN. There is always a match of the PLT_CN 

value to the CN value in the PLOT table. 

The name of the foreign key for each table is listed in the table description. It follows the 

nomenclature of 

‘SOURCETABLEABBREVIATION’_‘MATCHINGTABLEABBREVIATION’_FK, 

where the source table is the table containing the foreign key and the matching table is the 

table the foreign key matches. The foreign key usually matches the CN column of the 

matching table. Most tables in FIADB 4.0 have only one foreign key, but tables can have 

multiple foreign keys. 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Survey Table 

24 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Survey Table (Oracle table name is SURVEY) 

Column name Descriptive name Oracle data type 

1 CN Sequence number VARCHAR2(34) 

2 INVYR Inventory year NUMBER(4) 

3 P3_OZONE_IND Phase 3 ozone indicator VARCHAR2(1) 

4 STATECD State code NUMBER(4) 

5 STATEAB State abbreviation VARCHAR2(2) 

6 STATENM State name VARCHAR2(28) 

7 RSCD Region or station code NUMBER(2) 

8 ANN_INVENTORY Annual inventory VARCHAR2(1) 

9 NOTES Notes VARCHAR2(2000) 

10 CREATED_BY Created by VARCHAR2(30) 

11 CREATED_DATE Created date DATE 

12 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

13 MODIFIED_BY Modified by VARCHAR2(30) 

14 MODIFIED_DATE Modified date DATE 

15 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

16 CYCLE Inventory cycle number NUMBER(2) 

17 SUBCYCLE Inventory subcycle number NUMBER(2) 

Type of Key Column(s) order Tables to link Abbreviated notation 

Primary (CN) N/A SRV_PK 

Unique (STATECD, INVYR, 

P3_OZONE_IND, CYCLE) 

N/A SRV_UK 

 1. CN Sequence number. A unique sequence number used to identify a survey 

record. 

 2. INVYR Inventory year. The year that best represents when the inventory data were 

collected. Under the annual inventory system, a group of plots is selected 

each year for sampling. The selection is based on a panel system. INVYR is 

the year in which the majority of plots in that group were collected (plots in 

the group have the same panel and, if applicable, subpanel). Under periodic 

inventory, a reporting inventory year was selected, usually based on the year 

in which the majority of the plots were collected or the mid-point of the years 

over which the inventory spanned. For either annual or periodic inventory, 

INVYR is not necessarily the same as MEASYEAR. 

 Exceptions: 

 INVYR = 9999. INVYR is set to 9999 to distinguish Phase 3 plots taken by 

the western FIA work units that are “off subpanel.” This is due to differences 

in measurement intervals between Phase 3 (measurement interval = 5 years) 

and Phase 2 (measurement interval = 10 years) plots. Only users interested in 

performing certain Phase 3 data analyses should access plots with this 

anomalous value in INVYR. 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Survey Table 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 25

 INVYR <100. INVYR <100 indicates that population estimates were derived 

from a pre-NIMS regional processing system and the same plot either has 

been or may soon be re-processed in NIMS as part of a separate evaluation. 

The NIMS processed copy of the plot follows the standard INVYR format. 

This only applies to plots collected in the South (SURVEY.RSCD = 33) with 

the national design or a similar regional design (PLOT.DESIGNCD = 1 or 

220-233) that were collected when the inventory year was 1998 through 

2005. 

 INVYR = 98 is equivalent to 1998 but processed through regional system 

 INVYR = 99 is equivalent to 1999 but processed through regional system 

 INVYR = 0 is equivalent to 2000 but processed through regional system 

 INVYR = 1 is equivalent to 2001 but processed through regional system 

 INVYR = 2 is equivalent to 2002 but processed through regional system 

 INVYR = 3 is equivalent to 2003 but processed through regional system 

 INVYR = 4 is equivalent to 2004 but processed through regional system 

 INVYR = 5 is equivalent to 2005 but processed through regional system 

 3. P3_OZONE_IND 

 Phase 3 ozone indicator. Values are Y (yes) and N (no). If Y, then the Survey 

is for a P3 ozone inventory. If N, then the Survey is not for a P3 ozone 

inventory. Note that P3_OZONE_IND is part of the unique key because 

ozone data are stored as a separate inventory (survey); therefore, 

combinations of STATECD and INVYR may occur more than one time. 

 4. STATECD State code. Bureau of the Census Federal Information Processing Standards 

(FIPS) two-digit code for each State. Refer to appendix C. 

 5. STATEAB State abbreviation. The two-character State abbreviation. Refer to appendix 

C. 

 6. STATENM State name. Refer to appendix C. 

 7. RSCD Region or Station Code. Identification number of the Forest Service National 

Forest System Region or Station (FIA work unit) that provided the inventory 

data (see appendix C for more information). 

Code Description 

22 Rocky Mountain Research Station (RMRS) 

23 North Central Research Station (NCRS) 

24 Northeastern Research Station (NERS) 

26 Pacific Northwest Research Station (PNWRS) 

27 Pacific Northwest Research Station (PNWRS)-Alaska 

33 Southern Research Station (SRS) 
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Chapter 3. Survey Table 

26 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 8. ANN_INVENTORY 

 Annual Inventory. An indicator to show if a particular inventory was 

collected as an annual inventory or a periodic inventory. Values are Y or N, 

and Y means that the inventory is annual. 

 9. NOTES Notes. An optional item where notes about the inventory may be stored. 

 10. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 11. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 12. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 13. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 14. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 15. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 

 16. CYCLE Inventory cycle number. A number assigned to a set of plots, measured over 

a particular period of time from which a State estimate using all possible 

plots is obtained. A cycle number >1 does not necessarily mean that 

information for previous cycles resides in the database. A cycle is relevant 

for periodic and annual inventories. 

 17. SUBCYCLE Inventory subcycle number. For an annual inventory that takes n years to 

measure all plots, subcycle shows in which of the n years of the cycle the 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Survey Table 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 27

data were measured. Subcycle is 0 for a periodic inventory. Subcycle 99 may 

be used for plots that are not included in the estimation process. 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. County Table 

28 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

County Table (Oracle table name is COUNTY) 

Column name Descriptive name Oracle data type 

1 STATECD State code NUMBER(4) 

2 UNITCD Survey unit code NUMBER(2) 

3 COUNTYCD County code NUMBER(3) 

4 COUNTYNM County name VARCHAR2(50) 

5 CN Sequence number VARCHAR2(34) 

6 CREATED_BY Created by VARCHAR2(30) 

7 CREATED_DATE Created date DATE 

8 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

9 MODIFIED_BY Modified by VARCHAR2(30) 

10 MODIFIED_DATE Modified date DATE 

11 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (CN) N/A CTY_PK 

Unique (STATECD, UNITCD, COUNTYCD) N/A CTY_UK 

 1. STATECD State code. Bureau of the Census Federal Information Processing Standards 

(FIPS) two-digit code for each State. Refer to appendix C. 

 2. UNITCD Survey unit code. Forest Inventory and Analysis survey unit identification 

number. Survey units are usually groups of counties within each State. For 

periodic inventories, Survey units may be made up of lands of particular 

owners. Refer to appendix C for codes. 

 3. COUNTYCD County code. The identification number for a county, parish, watershed, 

borough, or similar governmental unit in a State. FIPS codes from the Bureau 

of the Census are used. Refer to appendix C for codes. 

 4. COUNTYNM County name. County name as recorded by the Bureau of the Census for 

individual counties, or the name given to a similar governmental unit by the 

FIA program. Only the first 50 characters of the name are used. Refer to 

appendix C for names. 

 5. CN Sequence number. A unique sequence number used to identify a county 

record. 

 6. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 7. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. County Table 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 29

 8. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 9. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 10. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 11. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Plot Table 

30 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Plot Table (Oracle table name is PLOT) 

Column name Descriptive name Oracle data type 

1 CN Sequence number VARCHAR2(34) 

2 SRV_CN Survey sequence number VARCHAR2(34) 

3 CTY_CN County sequence number VARCHAR2(34) 

4 PREV_PLT_CN Previous plot sequence number VARCHAR2(34) 

5 INVYR Inventory year NUMBER(4) 

6 STATECD State code NUMBER(4) 

7 UNITCD Survey unit code NUMBER(2) 

8 COUNTYCD County code NUMBER(3) 

9 PLOT Phase 2 plot number NUMBER(5) 

10 PLOT_STATUS_CD Plot status code NUMBER(1) 

11 PLOT_NONSAMPLE_REASN_CD Plot nonsampled reason code NUMBER(2) 

12 MEASYEAR Measurement year NUMBER(4) 

13 MEASMON Measurement month NUMBER(2) 

14 MEASDAY Measurement day NUMBER(2) 

15 REMPER Remeasurement period NUMBER(3,1) 

16 KINDCD Sample kind code NUMBER(2) 

17 DESIGNCD Plot design code NUMBER(4) 

18 RDDISTCD Horizontal distance to improved road code NUMBER(2) 

19 WATERCD Water on plot code NUMBER(2) 

20 LAT Latitude NUMBER(8,6) 

21 LON Longitude NUMBER(9,6) 

22 ELEV Elevation NUMBER(5) 

23 GROW_TYP_CD Type of annual volume growth code NUMBER(2) 

24 MORT_TYP_CD Type of annual mortality volume code NUMBER(2) 

25 P2PANEL Phase 2 panel number NUMBER(2) 

26 P3PANEL Phase 3 panel number NUMBER(2) 

27 ECOSUBCD Ecological subsection code VARCHAR2(7) 

28 CONGCD Congressional district code NUMBER(4) 

29 MANUAL Manual (field guide) version number NUMBER(3,1) 

30 SUBPANEL Subpanel NUMBER(2) 

31 KINDCD_NC Sample kind code, North Central NUMBER(2) 

32 QA_STATUS Quality assurance status NUMBER(1) 

33 CREATED_BY Created by VARCHAR2(30) 

34 CREATED_DATE Created date DATE 

35 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

36 MODIFIED_BY Modified by VARCHAR2(30) 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 31

Column name Descriptive name Oracle data type 

37 MODIFIED_DATE Modified date DATE 

38 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

39 MICROPLOT_LOC Microplot location VARCHAR2(12) 

40 DECLINATION Declination NUMBER(4,1) 

41 EMAP_HEX EMAP hexagon NUMBER(7) 

42 SAMP_METHOD_CD Sample method code NUMBER(1) 

43 SUBP_EXAMINE_CD Subplots examined code NUMBER(1) 

44 MACRO_BREAKPOINT_DIA Macroplot breakpoint diameter NUMBER(2) 

45 INTENSITY Intensity VARCHAR2(2) 

46 CYCLE Inventory cycle number NUMBER(2) 

47 SUBCYCLE Inventory subcycle number NUMBER(2) 

48 ECO_UNIT_PNW Ecological unit, Pacific Northwest 

Research Station VARCHAR2(10) 

49 TOPO_POSITION_PNW Topographic position, Pacific Northwest 

Research Station VARCHAR2(2) 

50 NF_SAMPLING_STATUS_CD Nonforest sampling status code NUMBER(1) 

51 NF_PLOT_STATUS_CD Nonforest plot status cd NUMBER(1) 

52 NF_PLOT_NONSAMPLE_REASN_

CD Nonforest plot nonsampled reason code NUMBER(2) 

53 P2VEG_SAMPLING_STATUS_CD P2 vegetation sampling status code NUMBER(1) 

54 P2VEG_SAMPLING_LEVEL_ 

DETAIL_CD P2 vegetation sampling level detail code NUMBER(1) 

55 INVASIVE_SAMPLING_STATUS_

CD Invasive sampling status code NUMBER(1) 

56 INVASIVE_SPECIMEN_RULE_ 

CD Invasive specimen rule code NUMBER(1) 

Type of Key Column(s) order Tables to link Abbreviated notation 

Primary (CN) N/A PLT_PK 

Unique (STATECD, INVYR, UNITCD, 

COUNTYCD, PLOT) 

N/A PLT_UK 

Foreign (CTY_CN) PLOT to COUNTY PLT_CTY_FK 

(SRV_CN) PLOT to SURVEY PLT_SRV_FK 

 1. CN Sequence number. A unique sequence number used to identify a plot record. 

 2. SRV_CN Survey sequence number. Foreign key linking the plot record to the survey 

record. 

 3. CTY_CN County sequence number. Foreign key linking the plot record to the county 

record. 
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32 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 4. PREV_PLT_CN 

 Previous plot sequence number. Foreign key linking the plot record to the 

previous inventory’s plot record for this location. Only populated on 

remeasurement plots. 

 5. INVYR Inventory year. The year that best represents when the inventory data were 

collected. Under the annual inventory system, a group of plots is selected 

each year for sampling. The selection is based on a panel system. INVYR is 

the year in which the majority of plots in that group were collected (plots in 

the group have the same panel and, if applicable, subpanel). Under periodic 

inventory, a reporting inventory year was selected, usually based on the year 

in which the majority of the plots were collected or the mid-point of the years 

over which the inventory spanned. For either annual or periodic inventory, 

INVYR is not necessarily the same as MEASYEAR. 

 Exceptions: 

 INVYR = 9999. INVYR is set to 9999 to distinguish Phase 3 plots taken by 

the western FIA work units that are “off subpanel.” This is due to differences 

in measurement intervals between Phase 3 (measurement interval = 5 years) 

and Phase 2 (measurement interval = 10 years) plots. Only users interested in 

performing certain Phase 3 data analyses should access plots with this 

anomalous value in INVYR. 

 INVYR <100. INVYR <100 indicates that population estimates were derived 

from a pre-NIMS regional processing system and the same plot either has 

been or may soon be re-processed in NIMS as part of a separate evaluation. 

The NIMS processed copy of the plot follows the standard INVYR format. 

This only applies to plots collected in the South (SURVEY.RSCD = 33) with 

the national design or a similar regional design (DESIGNCD = 1 or 220-233) 

that were collected when the inventory year was 1998 through 2005. 

 INVYR = 98 is equivalent to 1998 but processed through regional system 

 INVYR = 99 is equivalent to 1999 but processed through regional system 

 INVYR = 0 is equivalent to 2000 but processed through regional system 

 INVYR = 1 is equivalent to 2001 but processed through regional system 

 INVYR = 2 is equivalent to 2002 but processed through regional system 

 INVYR = 3 is equivalent to 2003 but processed through regional system 

 INVYR = 4 is equivalent to 2004 but processed through regional system 

 INVYR = 5 is equivalent to 2005 but processed through regional system 

 6. STATECD State code. Bureau of the Census Federal Information Processing Standards 

(FIPS) two-digit code for each State. Refer to appendix C. 

 7. UNITCD Survey unit code. Forest Inventory and Analysis survey unit identification 

number. Survey units are usually groups of counties within each State. For 

periodic inventories, Survey units may be made up of lands of particular 

owners. Refer to appendix C for codes. 
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Chapter 3. Plot Table 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 33

 8. COUNTYCD County code. The identification number for a county, parish, watershed, 

borough, or similar governmental unit in a State. FIPS codes from the Bureau 

of the Census are used. Refer to appendix C for codes. 

 9. PLOT Phase 2 plot number. An identifier for a plot. Along with STATECD, 

INVYR, UNITCD, COUNTYCD and/or some other combinations of 

variables, PLOT may be used to uniquely identify a plot. 

 10. PLOT_STATUS_CD 

Plot status code. A code that describes the sampling status of the plot. Blank 

(null) values may be present for periodic inventories. 

Code Description 

1 Sampled – at least one accessible forest land condition present on plot 

2 Sampled – no accessible forest land condition present on plot 

3 Nonsampled 

 11. PLOT_NONSAMPLE_REASN_CD 

Plot nonsampled reason code. For entire plots that cannot be sampled, one of 

the following reasons is recorded. 

Code Description 

01 Outside U.S. boundary – Entire plot is outside of the U.S. border. 

02 Denied access area – Access to the entire plot is denied by the legal 

owner, or by the owner of the only reasonable route to the plot. 

03 Hazardous – Entire plot cannot be accessed because of a hazard or 

danger, for example cliffs, quarries, strip mines, illegal substance 

plantations, high water, etc. 

05 Lost data – Plot data file was discovered to be corrupt after a panel was 

completed and submitted for processing. 

06 Lost plot – Entire plot cannot be found. 

07 Wrong location – Previous plot can be found, but its placement is beyond 

the tolerance limits for plot location. 

08 Skipped visit – Entire plot skipped. Used for plots that are not completed 

prior to the time a panel is finished and submitted for processing. This 

code is for office use only. 

09 Dropped intensified plot – Intensified plot dropped due to a change in 

grid density. This code used only by units engaged in intensification. This 

code is for office use only. 

10 Other – Entire plot not sampled due to a reason other than one of the 

specific reasons already listed. 

11 Ocean – Plot falls in ocean water below mean high tide line. 

 12. MEASYEAR Measurement year. The year in which the plot was completed. MEASYEAR 

may differ from INVYR. 
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Chapter 3. Plot Table 

34 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 13. MEASMON Measurement month. The month in which the plot was completed. May be 

blank (null) for periodic inventory. 

Code Description Code Description 

01 January 07 July 

02 February 08 August 

03 March 09 September 

04 April 10 October 

05 May 11 November 

06 June 12 December 

 14. MEASDAY Measurement day. The day of the month in which the plot was completed. 

May be blank (null) for periodic inventory. 

 15. REMPER Remeasurement period. The number of years between measurements for 

remeasured plots. This attribute is null (blank) for new plots or remeasured 

plots that are not used for growth, removals, or mortality estimates. For data 

processed with NIMS, REMPER is the number of years between 

measurements (to the nearest 0.1 year). For data processed with systems 

other than NIMS, remeasurement period is based on the number of growing 

seasons between measurements. Allocation of parts of the growing season by 

month is different for each FIA work unit. Contact the appropriate FIA work 

unit for information on how this is done for a particular State. NOTE: it is 

not valid to use REMPER to estimate periodic change. 

 16. KINDCD Sample kind code. A code indicating the type of plot installation. Database 

users may also want to examine DESIGNCD to obtain additional information 

about the kind of plot being selected. 

Code Description 

0 Periodic inventory plot 

1 Initial installation of a National design plot 

2 Remeasurement of previously installed National design plot 

3 Replacement of previously installed National design plot 

4 Modeled periodic inventory plot (Northeastern and North Central only) 

 17. DESIGNCD Plot design code. A code indicating the type of plot design used to collect the 

data. Refer to appendix B for a list of codes and descriptions. 

 18. RDDISTCD Horizontal distance to improved road code. The straight-line distance from 

plot center to the nearest improved road, which is a road of any width that is 

maintained as evidenced by pavement, gravel, grading, ditching, and/or other 

improvements. Populated for all forested plots using the National Field Guide 

protocols (MANUAL ≥1.0) and populated by some FIA work units for 

inventory plots collected where MANUAL <1.0. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 35

Code Description 

1 100 ft or less 

2 101 ft to 300 ft 

3 301 ft to 500 ft 

4 501 ft to 1000 ft 

5 1001 ft to 1/2 mile 

6 1/2 to 1 mile 

7 1 to 3 miles 

8 3 to 5 miles 

9 Greater than 5 miles 

 19. WATERCD Water on plot code. Water body <1 acre in size or a stream <30 feet wide that 

has the greatest impact on the area within the forest land portion of the four 

subplots. The coding hierarchy is listed in order from large permanent water 

to temporary water. Populated for all forested plots using the National Field 

Guide protocols (MANUAL ≥1.0) and populated by some FIA work units for 

inventory plots collected where MANUAL <1.0. 

Code Description 

0 None – no water sources within the accessible forest land condition class 

1 Permanent streams or ponds too small to qualify as noncensus water 

2 Permanent water in the form of deep swamps, bogs, marshes without standing 

trees present and less than 1.0 acre in size, or with standing trees 

3 Ditch/canal – human-made channels used as a means of moving water, e.g., for 

irrigation or drainage, which are too small to qualify as noncensus water 

4 Temporary streams 

5 Flood zones – evidence of flooding when bodies of water exceed their natural 

banks 

9 Other temporary water – specified in plot-level notes. 

 

 20. LAT Latitude. The approximate latitude of the plot in decimal degrees using NAD 

83 datum. Actual plot coordinates cannot be released because of a Privacy 

provision enacted by Congress in the Food Security Act of 1985. Therefore, 

this attribute is approximately +/- 1 mile and, for annual inventory data, most 

plots are within +/- 1⁄2 mile. Annual data have additional uncertainty for 

private plots caused by swapping plot coordinates for up to 20 percent of the 

plots. In some cases, the county centroid is used when the actual coordinate is 

not available. 

 21. LON Longitude. The approximate longitude of the plot in decimal degrees using 

NAD 83 datum. Actual plot coordinates cannot be released because of a 

Privacy provision enacted by Congress in the Food Security Act of 1985. 

Therefore, this attribute is approximately +/- 1 mile and, for annual inventory 

data, most plots are within +/- 1⁄2 mile. Annual data have additional 

uncertainty for private plots caused by swapping plot coordinates for up to 20 

percent of the plots. In some cases, the county centroid is used when the 

actual coordinate is not available. 

 22. ELEV Elevation. The distance the plot is located above sea level, recorded in feet 

(NAD 83 datum). Negative values indicate distance below sea level. 
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36 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 23. GROW_TYP_CD 

 Type of annual volume growth code. A code indicating how volume growth 

is estimated. Current annual growth is an estimate of the amount of volume 

that was added to a tree in the year before the tree was sampled, and is based 

on the measured diameter increment recorded when the tree was sampled or 

on a modeled diameter for the previous year. Periodic annual growth is an 

estimate of the average annual change in volume occurring between two 

measurements, usually the current inventory and the previous inventory, 

where the same plot is evaluated twice. Periodic annual growth is the 

increase in volume between inventories divided by the number of years 

between each inventory. This attribute is blank (null) if the plot does not 

contribute to the growth estimate. 

Code Description 

1 Current annual 

2 Periodic annual 

 

24. MORT_TYP_CD 

 Type of annual mortality volume code. A code indicating how mortality 

volume is estimated. Current annual mortality is an estimate of the volume of 

trees dying in the year before the plot was measured, and is based on the year 

of death or on a modeled estimate. Periodic annual mortality is an estimate of 

the average annual volume of trees dying between two measurements, 

usually the current inventory and previous inventory, where the same plot is 

evaluated twice. Periodic annual mortality is the loss of volume between 

inventories divided by the number of years between each inventory. Periodic 

average annual mortality is the most common type of annual mortality 

estimated. This attribute is blank (null) if the plot does not contribute to the 

mortality estimate. 

Code Description 

1 Current annual 

2 Periodic annual 

 

 25. P2PANEL Phase 2 panel number. The value for P2PANEL ranges from 1 to 7 for annual 

inventories and is blank (null) for periodic inventories. A panel is a sample in 

which the same elements are measured on two or more occasions. FIA 

divides the plots in each State into 5 or 7 panels that can be used to 

independently sample the population. 

 26. P3PANEL Phase 3 panel number. A panel is a sample in which the same elements are 

measured on two or more occasions. FIA divides the plots in each State into 

5 or 7 panels that can be used to independently sample the population. The 

value for P3PANEL ranges from 1 to 7 for those plots where Phase 3 data 

were collected. If the plot is not a Phase 3 plot, then this attribute is left blank 

(null). 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 37

 27. ECOSUBCD Ecological subsection code. An area of similar surficial geology, lithology, 

geomorphic process, soil groups, subregional climate, and potential natural 

communities. Subsection boundaries usually correspond with discrete 

changes in geomorphology. Subsection information is used for broad 

planning and assessment. Subsection codes for the coterminous United States 

were developed as part of the “Forest Service Map of Provinces, Sections, 

and Subsections of the United States (Cleland and others 2007) (visit 

http://fsgeodata.fs.fed.us/other_resources/ecosubregions.html). For southeast 

and south coastal Alaska, the subsection codes are based on the ecological 

sections as designated in the “Ecoregions and Subregions of Alaska, EcoMap 

version 2.0” (Nowacki and Brock 1995) (visit 

http://agdcftp1.wr.usgs.gov/pub/projects/fhm/ecomap.gif). The ECOSUBCD 

is based on fuzzed and swapped plot coordinates. This attribute is coded for 

the coterminous United States, southeast and south coastal Alaska, and is left 

blank (null) in all other instances. 

 28. CONGCD Congressional district code. A territorial division of a State from which a 

member of the U.S. House of Representatives is elected. The congressional 

district code assigned to a plot (regardless of when it was measured) is for the 

current Congress; the assignment is made based on the plot’s approximate 

coordinates. CONGCD is a four-digit number. The first two digits are the 

State FIPS code and the last two digits are the congressional district number. 

If a State has only one congressional district, the congressional district 

number is 00. If a plot’s congressional district assignment falls in a State 

other than the plot’s actual State due to using the approximate coordinates, 

the congressional district code will be for the nearest congressional district in 

the correct State. This attribute is coded for the coterminous States and 

Alaska, and is left blank (null) in all other instances. For more information 

about the coverage used to assign this attribute, see National Atlas of the 

United States (2007). 

 29. MANUAL Manual (field guide) version number. Version number of the Field Guide 

used to describe procedures for collecting data on the plot. The National FIA 

Field Guide began with version 1.0; therefore data taken using the National 

Field procedures will have PLOT.MANUAL ≥1.0. Data taken according to 

field instructions prior to the use of the National Field Guide have 

PLOT.MANUAL <1.0. 

 30. SUBPANEL Subpanel. Subpanel assignment for the plot for those FIA work units using 

subpaneling. FIA uses a 5-panel system (see P2PANEL) to divide plot 

sampling over a 5-year period. Funding for western FIA work units is only 

sufficient to allow plot sampling over a 10-year period. Therefore, panels are 

further divided into subpanels. This attribute is left blank (null) if 

subpaneling is not used. In some States, seven panels are used and 

SUBPANEL is blank (null). 
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38 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 31. KINDCD_NC Sample kind code, North Central. This attribute is populated through 2005 

for the former North Central work unit (SURVEY.RSCD = 23) and is blank 

(null) for all other FIA work units. 

Code Description 

0 New/lost 

6 Remeasured 

8 Old location but not remeasured 

20 Skipped 

33 Replacement of lost plot 

 32. QA_STATUS Quality assurance status. A code indicating the type of plot data collected. 

Populated for all forested subplots using the National Field Guide protocols 

(MANUAL ≥1.0). 

Code Description 

1 Standard production plot 

2 Cold check 

3 Reference plot (off grid) 

4 Training/practice plot (off grid) 

5 Botched plot file (disregard during data processing) 

6 Blind check 

7 Production plot (hot check) 

 33. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 34. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 35. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 36. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 37. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 39

 38. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 

 39. MICROPLOT_LOC 

 Microplot location. Values are 'OFFSET' or 'CENTER.' The offset microplot 

center is located 12 feet due east (90 degrees) of subplot center. The current 

standard is that the microplot is located in the ‘OFFSET’ location, but some 

earlier inventories, including some early panels of the annual inventory, may 

contain data where the microplot was located at the ‘CENTER’ location. 

Populated for annual inventory and may be populated for periodic inventory. 

 40. DECLINATION 

Declination. (Core optional.) The azimuth correction used to adjust magnetic 

north to true north. All azimuths are assumed to be magnetic azimuths unless 

otherwise designated. The Portland FIA work unit historically has corrected 

all compass readings for true north. This field is to be used only in cases 

where FIA work units are adjusting azimuths to correspond to true north; for 

FIA work units using magnetic azimuths, this field will always be set = 0 in 

the office. This field carries a decimal place because the USGS corrections 

are provided to the nearest half degree. DECLINATION is defined as: 

 DECLINATION = (TRUE NORTH - MAGNETIC NORTH) 

 41. EMAP_HEX EMAP hexagon. The identifier for the approximately 160,000 acre 

Environmental Monitoring and Assessment Program (EMAP) hexagon in 

which the plot is located. EMAP hexagons are available to the public, cover 

the coterminous United States, and have been used in summarizing and 

aggregating data about numerous natural resources. Populated for annual 

inventory and may be populated for periodic inventory. 

 42. SAMP_METHOD_CD 

 Sample method code. A code indicating if the plot was observed in the field 

or remotely sensed in the office. 

Code Description 

1 Field visited, meaning a field crew physically examined the plot and recorded 

information at least about subplot 1 center condition (see 

SUBP_EXAMINE_CD below). 

2 Remotely sensed, meaning a determination was made using some type of 

imagery that a field visit was not necessary. When the plot is sampled 

remotely, the number of subplots examined (SUBP_EXAMINE_CD) usually 

equals 1. 
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40 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 43. SUBP_EXAMINE_CD 

 Subplots examined code. A code indicating the number of subplots 

examined. By default, PLOT_STATUS_CD = 1 plots have all 4 subplots 

examined. 

Code Description 

1 Only subplot 1 center condition examined and all other subplots assumed 

(inferred) to be the same 

4 All four subplots fully described (no assumptions/inferences) 

 44. MACRO_BREAKPOINT_DIA 

 Macroplot breakpoint diameter. (Core optional.) A macroplot breakpoint 

diameter is the diameter (either DBH or DRC) above which trees are 

measured on the plot extending from 0.01 to 58.9 feet horizontal distance 

from the center of each subplot. Examples of different breakpoint diameters 

used by western FIA work units are 24 inches or 30 inches (Pacific 

Northwest), or 21 inches (Interior West). Installation of macroplots is core 

optional and is used to have a larger plot size in order to more adequately 

sample large trees. If macroplots are not being installed, this item will be left 

blank (null). 

 45. INTENSITY Intensity. A code used to identify federal base grid annual inventory plots and 

plots that have been added to intensify a particular sample. Under the federal 

base grid, one plot is collected in each theoretical hexagonal polygon, which 

is slightly more than 5,900 acres in size. Plots with INTENSITY = 1 are part 

of the federal base grid. In some instances, States and/or agencies have 

provided additional support to increase the sampling intensity for an area. 

Supplemental plots have INTENSITY set to higher numbers depending on 

the amount of plot intensification chosen for the particular estimation unit. 

Populated for annual inventory data only. 

 46. CYCLE Inventory cycle number. A number assigned to a set of plots, measured over 

a particular period of time from which a State estimate using all possible 

plots is obtained. A cycle number >1 does not necessarily mean that 

information for previous cycles resides in the database. A cycle is relevant 

for periodic and annual inventories. 

 47. SUBCYCLE Inventory subcycle number. For an annual inventory that takes n years to 

measure all plots, subcycle shows in which of the n years of the cycle the 

data were measured. Subcycle is 0 for a periodic inventory. Subcycle 99 may 

be used for plots that are not included in the estimation process. 

 48. ECO_UNIT_PNW 

 Ecological unit, Pacific Northwest Research Station. Plots taken by PNW 

FIA are assigned to the ecological unit in which they are located. Certain 

units have stocking adjustments made to the plots that occur on very low 

productivity lands, which thereby reduces the estimated potential 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 41

productivity of the plot. More information can be found in MacLean (1973). 

Only collected by certain FIA work units (SURVEY.RSCD = 26 or 27). 

 49. TOPO_POSITION_PNW 

Topographic position, Pacific Northwest Research Station. The topographic 

position that describes the plot area. Illustrations available in Plot section of 

PNW field guide located at: 

http//www.fs.fed.us/pnw/fia/publications/fieldmanuals.shtml. Adapted from 

information found in Wilson (1900). Only collected by certain FIA work 

units (SURVEY.RSCD = 26). 

Code Topographic position Common shape of slope 

1 Ridge top or mountain peak over 130 feet Flat 

2 Narrow ridge top or mountain peak over 130 feet wide Convex 

3 Side hill – upper 1/3 Convex 

4 Side hill – middle 1/3 No rounding 

5 Side hill – lower 1/3 Concave 

6 Canyon bottom less than 660 feet wide Concave 

7 Bench, terrace or dry flat Flat 

8 Broad alluvial flat over 660 feet wide Flat 

9 Swamp or wet flat Flat 

 50. NF_SAMPLING_STATUS_CD 

 Nonforest sampling status code. Intentionally left blank. Will be populated in 

version 5.0. 

 51. NF_PLOT_STATUS_CD 

 Nonforest plot status code. Intentionally left blank. Will be populated in 

version 5.0. 

 52. NF_PLOT_NONSAMPLE_REASN_CD 

 Nonforest plot nonsampled reason code. Intentionally left blank. Will be 

populated in version 5.0. 

 53. P2VEG_SAMPLING_STATUS_CD 

 P2 vegetation sampling status code. Intentionally left blank. Will be 

populated in version 5.0. 

 54. P2VEG_SAMPLING_LEVEL_DETAIL_CD 

 P2 vegetation sampling level detail code. Intentionally left blank. Will be 

populated in version 5.0. 

 55. INVASIVE_SAMPLING_STATUS_CD 

 Invasive sampling status code. Intentionally left blank. Will be populated in 

version 5.0. 
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42 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 56. INVASIVE_SPECIMEN_RULE_CD 

 Invasive specimen rule code. Intentionally left blank. Will be populated in 

version 5.0. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 43

Condition Table (Oracle table name is COND) 

Column name Descriptive name Oracle data type 

1 CN Sequence number VARCHAR2(34) 

2 PLT_CN Plot sequence number VARCHAR2(34) 

3 INVYR Inventory year NUMBER(4) 

4 STATECD State code NUMBER(4) 

5 UNITCD Survey unit code NUMBER(2) 

6 COUNTYCD County code NUMBER(3) 

7 PLOT Phase 2 plot number NUMBER(5) 

8 CONDID Condition class number NUMBER(1) 

9 COND_STATUS_CD Condition status code NUMBER(1) 

10 COND_NONSAMPLE_ 

REASN_CD Condition nonsampled reason code NUMBER(2) 

11 RESERVCD Reserved status code NUMBER(2) 

12 OWNCD Owner class code NUMBER(2) 

13 OWNGRPCD Owner group code NUMBER(2) 

14 FORINDCD Private owner industrial status code NUMBER(2) 

15 ADFORCD Administrative forest code NUMBER(4) 

16 FORTYPCD Forest type code, derived by algorithm NUMBER(3) 

17 FLDTYPCD Field forest type code NUMBER(3) 

18 MAPDEN Mapping density NUMBER(1) 

19 STDAGE Stand age NUMBER(4) 

20 STDSZCD Stand-size class code derived by algorithm NUMBER(2) 

21 FLDSZCD Field stand-size class code NUMBER(2) 

22 SITECLCD Site productivity class code NUMBER(2) 

23 SICOND Site index for the condition NUMBER(3) 

24 SIBASE Site index base age NUMBER(3) 

25 SISP Site index species code NUMBER(4) 

26 STDORGCD Stand origin code NUMBER(2) 

27 STDORGSP Stand origin species code NUMBER 

28 PROP_BASIS Proportion basis VARCHAR2(12) 

29 CONDPROP_UNADJ Condition proportion unadjusted NUMBER(5,4) 

30 MICRPROP_UNADJ Microplot proportion unadjusted NUMBER(5,4) 

31 SUBPPROP_UNADJ Subplot proportion unadjusted NUMBER(5,4) 

32 MACRPROP_UNADJ Macroplot proportion unadjusted NUMBER(5,4) 

33 SLOPE Slope NUMBER(3) 

34 ASPECT Aspect NUMBER(3) 

35 PHYSCLCD Physiographic class code NUMBER(2) 

36 GSSTKCD Growing-stock stocking code NUMBER(2) 

37 ALSTKCD All live stocking code NUMBER(2) 

38 DSTRBCD1 Disturbance 1 code NUMBER(2) 
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44 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Column name Descriptive name Oracle data type 

39 DSTRBYR1 Disturbance year 1 NUMBER(4) 

40 DSTRBCD2 Disturbance 2 code NUMBER(2) 

41 DSTRBYR2 Disturbance year 2 NUMBER(4) 

42 DSTRBCD3 Disturbance 3 code NUMBER(2) 

43 DSTRBYR3 Disturbance year 3 NUMBER(4) 

44 TRTCD1 Stand treatment 1 code NUMBER(2) 

45 TRTYR1 Treatment year 1 NUMBER(4) 

46 TRTCD2 Stand treatment 2 code NUMBER(2) 

47 TRTYR2 Treatment year 2 NUMBER(4) 

48 TRTCD3 Stand treatment 3 code NUMBER(2) 

49 TRTYR3 Treatment year 3 NUMBER(4) 

50 PRESNFCD Present nonforest code NUMBER(2) 

51 BALIVE Basal area of live trees NUMBER(9,4) 

52 FLDAGE Field-recorded stand age NUMBER(4) 

53 ALSTK All-live-tree stocking percent NUMBER(7,4) 

54 GSSTK Growing-stock stocking percent NUMBER(7,4) 

55 FORTYPCDCALC Forest type code calculated NUMBER(3) 

56 HABTYPCD1 Habitat type code 1 VARCHAR2(10) 

57 HABTYPCD1_PUB_CD Habitat type code 1 publication code VARCHAR2(10) 

58 HABTYPCD1_DESCR_ 

PUB_CD 

Habitat type code 1 description publication 

code VARCHAR2(10) 

59 HABTYPCD2 Habitat type code 2 VARCHAR2(10) 

60 HABTYPCD2_PUB_CD Habitat type code 2 publication code VARCHAR2(10) 

61 HABTYPCD2_DESCR_ 

PUB_CD 

Habitat type code 2 description publication 

code VARCHAR2(10) 

62 MIXEDCONFCD Mixed conifer code VARCHAR2(1) 

63 VOL_LOC_GRP Volume location group VARCHAR2(200) 

64 SITECLCDEST Site productivity class code estimated NUMBER(2) 

65 SITETREE_TREE Site tree tree number NUMBER(4) 

66 SITECL_METHOD Site class method NUMBER(2) 

67 CARBON_DOWN_DEAD Carbon in down dead NUMBER(13,6) 

68 CARBON_LITTER Carbon in litter NUMBER(13,6) 

69 CARBON_SOIL_ORG Carbon in soil organic material NUMBER(13,6) 

70 CARBON_STANDING_DEAD Carbon in standing dead trees NUMBER(13,6) 

71 CARBON_UNDERSTORY_AG Carbon in the understory aboveground NUMBER(13,6) 

72 CARBON_UNDERSTORY_BG Carbon in the understory belowground NUMBER(13,6) 

73 CREATED_BY Created by VARCHAR2(30) 

74 CREATED_DATE Created date DATE 

75 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

76 MODIFIED_BY Modified by VARCHAR2(30) 
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Column name Descriptive name Oracle data type 

77 MODIFIED_DATE Modified date DATE 

78 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

79 CYCLE Inventory cycle number NUMBER(2) 

80 SUBCYCLE Inventory subcycle number NUMBER(2) 

81 SOIL_ROOTING_DEPTH_ 

PNW 

Soil rooting depth, Pacific Northwest 

Research Station VARCHAR2(1) 

82 GROUND_LAND_CLASS_ 

PNW 

Present ground land class, Pacific 

Northwest Research Station VARCHAR2(3) 

83 PLANT_STOCKABILITY_ 

FACTOR_PNW 

Plant stockability factor, Pacific Northwest 

Research Station NUMBER 

84 STND_COND_CD_PNWRS Stand condition code, Pacific Northwest 

Research Station NUMBER(1) 

85 STND_STRUC_CD_ 

PNWRS 

Stand structure code, Pacific Northwest 

Research Station NUMBER(1) 

86 STUMP_CD_PNWRS Stump code, Pacific Northwest Research 

Station VARCHAR2(1) 

87 FIRE_SRS Fire, Southern Research Station NUMBER(1) 

88 GRAZING_SRS Grazing, Southern Research Station NUMBER(1) 

89 HARVEST_TYPE1_SRS Harvest type code 1, Southern Research 

Station NUMBER(2) 

90 HARVEST_TYPE2_SRS Harvest type code 2, Southern Research 

Station NUMBER(2) 

91 HARVEST_TYPE3_SRS Harvest type code 3, Southern Research 

Station NUMBER(2) 

92 LAND_USE_SRS Land use, Southern Research Station NUMBER(2) 

93 OPERABILITY_SRS Operability, Southern Research Station NUMBER(2) 

94 STAND_STRUCTURE_SRS Stand structure, Southern Research Station NUMBER(2) 

95 NF_COND_STATUS_CD Nonforest condition status code NUMBER(1) 

96 NF_COND_NONSAMPLE_ 

REASN_CD 

Nonforest condition nonsampled reason 

code NUMBER(2) 

97 CANOPY_CVR_SAMPLE_ 

METHOD_CD Canopy cover sample method code NUMBER(2) 

98 LIVE_CANOPY_CVR_ 

PCT Live canopy cover percent NUMBER(3) 

99 LIVE_MISSING_CANOPY_ 

CVR_PCT Live plus missing canopy cover percent NUMBER(3) 

100 NBR_LIVE_STEMS Number of live stems NUMBER(5) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (CN) N/A CND_PK 

Unique (PLT_CN, CONDID) N/A CND_UK 

Natural (STATECD, INVYR, UNITCD, 

COUNTYCD, PLOT, CONDID) 

N/A CND_NAT_I 

Foreign (PLT_CN) CONDITION to PLOT CND_PLT_FK 

 1. CN Sequence number. A unique sequence number used to identify a condition 

record. 
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46 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 2. PLT_CN Plot sequence number. Foreign key linking the condition record to the plot 

record. 

 3. INVYR Inventory year. The year that best represents when the inventory data were 

collected. Under the annual inventory system, a group of plots is selected 

each year for sampling. The selection is based on a panel system. INVYR is 

the year in which the majority of plots in that group were collected (plots in 

the group have the same panel and, if applicable, subpanel). Under periodic 

inventory, a reporting inventory year was selected, usually based on the year 

in which the majority of the plots were collected or the mid-point of the years 

over which the inventory spanned. For either annual or periodic inventory, 

INVYR is not necessarily the same as MEASYEAR. 

 Exceptions: 

 INVYR = 9999. INVYR is set to 9999 to distinguish Phase 3 plots taken by 

the western FIA work units that are “off subpanel.” This is due to differences 

in measurement intervals between Phase 3 (measurement interval = 5 years) 

and Phase 2 (measurement interval = 10 years) plots. Only users interested in 

performing certain Phase 3 data analyses should access plots with this 

anomalous value in INVYR. 

 INVYR <100. INVYR <100 indicates that population estimates were derived 

from a pre-NIMS regional processing system and the same plot either has 

been or may soon be re-processed in NIMS as part of a separate evaluation. 

The NIMS processed copy of the plot follows the standard INVYR format. 

This only applies to plots collected in the South (SURVEY.RSCD = 33) with 

the national design or a similar regional design (PLOT.DESIGNCD = 1 or 

220-233) that were collected when the inventory year was 1998 through 

2005. 

 INVYR = 98 is equivalent to 1998 but processed through regional system 

 INVYR = 99 is equivalent to 1999 but processed through regional system 

 INVYR = 0 is equivalent to 2000 but processed through regional system 

 INVYR = 1 is equivalent to 2001 but processed through regional system 

 INVYR = 2 is equivalent to 2002 but processed through regional system 

 INVYR = 3 is equivalent to 2003 but processed through regional system 

 INVYR = 4 is equivalent to 2004 but processed through regional system 

 INVYR = 5 is equivalent to 2005 but processed through regional system 

 4. STATECD State code. Bureau of the Census Federal Information Processing Standards 

(FIPS) two-digit code for each State. Refer to appendix C. 

 5. UNITCD Survey unit code. Forest Inventory and Analysis survey unit identification 

number. Survey units are usually groups of counties within each State. For 

periodic inventories, survey units may be made up of lands of particular 

owners. Refer to appendix C for codes. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 47

 6. COUNTYCD County code. The identification number for a county, parish, watershed, 

borough, or similar governmental unit in a State. FIPS codes from the Bureau 

of the Census are used. Refer to appendix C for codes. 

 7. PLOT Phase 2 plot number. An identifier for a plot. Along with STATECD, 

INVYR, UNITCD, COUNTYCD and/or some other combination of 

variables, PLOT may be used to uniquely identify a plot. 

 8. CONDID Condition class number. Unique identifying number assigned to each 

condition on a plot. A condition is initially defined by condition class status. 

Differences in reserved status, owner group, forest type, stand-size class, 

regeneration status, and stand density further define condition for forest land. 

Mapped nonforest conditions are also assigned numbers. At the time of the 

plot establishment, the condition class at plot center (the center of subplot 1) 

is usually designated as condition class 1. Other condition classes are 

assigned numbers sequentially at the time each condition class is delineated. 

On a plot, each sampled condition class must have a unique number that can 

change at remeasurement to reflect new conditions on the plot. 

 9. COND_STATUS_CD 

 Condition status code. A code indicating the basic land cover. 

Code Description 

1 Forest land – Land with at least 10 percent cover (or equivalent stocking) by 

live trees of any size, including land that formerly had such tree cover and that 

will be naturally or artificially regenerated. To qualify, the area must be at least 

1.0 acre in size and 120.0 feet wide. Forest land includes transition zones, such 

as areas between forest and nonforest lands that have at least 10 percent cover 

(or equivalent stocking) with live trees and forest areas adjacent to urban and 

built-up lands. Roadside, streamside, and shelterbelt strips of trees must have a 

width of at least 120 feet and continuous length of at least 363 feet to qualify as 

forest land. Unimproved roads and trails, streams, and clearings in forest areas 

are classified as forest if they are <120 feet wide or an acre in size. Treecovered areas in agricultural production settings, such as fruit orchards, or treecovered areas in urban settings, such as city parks, are not considered forest 

land. For data collected prior to annual inventory (PLOT.MANUAL <1.0), the 

definition for forest land may have been slightly different (for example, in the 

past some FIA work units used 5 percent cover rather than 10 percent.) 

2 Nonforest land – Any land within the sample that does not meet the definition 

of accessible forest land or any of the other types of basic land covers. To 

qualify, the area must be at least 1.0 acre in size and 120.0 feet wide, with some 

exceptions that are described in the document “Forest inventory and analysis 

national core field guide, volume 1: field data collection procedures for Phase 2 

plots, version 4.0.” (http://www.fia.fs.fed.us/library/field-guides-methodsproc/.) Evidence of "possible" or future development or conversion is not 

considered. A nonforest land condition will remain in the sample and will be 

examined at the next occasion to see if it has become forest land. 

3 Noncensus water – Lakes, reservoirs, ponds, and similar bodies of water 

1.0 acre to 4.5 acre in size. Rivers, streams, canals, etc., 30.0 feet to 200 feet 

wide (1990 U.S. Census definition – U.S. Census Bureau 1994). This definition 

was used in the 1990 census and applied when the data became available. 

Earlier inventories defined noncensus water differently. 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Condition Table 

48 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Code Description 

4 Census water – Lakes, reservoirs, ponds, and similar bodies of water 4.5 acre in 

size and larger; and rivers, streams, canals, etc., more than 200 feet wide (1990 

U.S. Census definition; U.S. Census Bureau 1994). 

5 Nonsampled - Any portion of a plot within accessible forest land that cannot be 

sampled is delineated as a separate condition. There is no minimum size 

requirement. The reason the condition was not sampled is provided in 

COND_NONSAMPLE_REASN_CD. 

 10. COND_NONSAMPLE_REASN_CD 

Condition nonsampled reason code. For condition classes that cannot be 

sampled, one of the following reasons is recorded. 

Code Description 

01 Outside U.S. boundary – Condition class is outside the U.S. border. 

02 Denied access area – Access to the condition class is denied by the legal 

owner, or by the owner of the only reasonable route to the condition class. 

03 Hazardous situation – Condition class cannot be accessed because of a hazard 

or danger, for example cliffs, quarries, strip mines, illegal substance 

plantations, temporary high water, etc. 

05 Lost data – The data file was discovered to be corrupt after a panel was 

completed and submitted for processing. Used for the single condition that is 

required for this plot. This code is for office use only. 

06 Lost plot – Entire plot cannot be found. Used for the single condition that is 

required for this plot. 

07 Wrong location – Previous plot can be found, but its placement is beyond the 

tolerance limits for plot location. Used for the single condition that is required 

for this plot. 

08 Skipped visit – Entire plot skipped. Used for plots that are not completed prior 

to the time a panel is finished and submitted for processing. Used for the 

single condition that is required for this plot. This code is for office use only. 

09 Dropped intensified plot - Intensified plot dropped due to a change in grid 

density. Used for the single condition that is required for this plot. This code 

used only by units engaged in intensification. This code is for office use only. 

10 Other – Condition class not sampled due to a reason other than one of the 

specific reasons listed. 

11 Ocean – Condition falls in ocean water below mean high tide line. 

 11. RESERVCD Reserved status code. (Core for accessible forestland; Core optional for 

other sampled land.) Reserved land is land that is withdrawn by law(s) 

prohibiting the management of the land for the production of wood products. 

Code Description 

0 Not reserved 

1 Reserved 

 12. OWNCD Owner class code. (Core for all accessible forestland; Core optional for 

other sampled land.) A code indicating the class in which the landowner (at 

the time of the inventory) belongs. When PLOT.DESIGNCD = 999, 

OWNCD may be blank (null). 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Condition Table 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 49

Code Description 

11 National Forest System 

12 National Grassland 

13 Other Forest Service 

21 National Park Service 

22 Bureau of Land Management 

23 Fish and Wildlife Service 

24 Department of Defense/Energy 

25 Other federal 

31 State 

32 Local (County, Municipal, etc) 

33 Other non-federal public 

46 Undifferentiated private 

The following detailed private owner land codes are not available in this 

database because of the FIA data confidentiality policy. Users needing this type 

of information should contact the FIA Spatial Data Services (SDS) group by 

following the instructions provided at: http://www.fia.fs.fed.us/toolsdata/spatial/. 

Code Description 

41 Corporate 

42 Non-governmental conservation/natural resources organization 

43 Unincorporated local partnership/association/club 

44 Native American (Indian) 

45 Individual 

 

 13. OWNGRPCD Owner group code. (Core for all accessible forestland; Core optional for 

other sampled land.) A broader group of landowner classes. When 

PLOT.DESIGNCD = 999, OWNGRPCD may be blank (null). 

Code Description 

10 Forest Service (OWNCD 11, 12, 13) 

20 Other federal (OWNCD 21, 22, 23, 24, 25) 

30 State and local government (OWNCD 31, 32, 33) 

40 Private (OWNCD 41, 42, 43, 44, 45, 46) 

 

 14. FORINDCD Private owner industrial status code. (Core for all accessible forestland 

where owner group is private; Core optional for other sampled land where 

owner group is private.) A code indicating whether the landowner owns and 

operates a primary wood processing plant. A primary wood processing plant 

is any commercial operation that originates the primary processing of wood 

on a regular and continuing basis. Examples include: pulp or paper mill, 

sawmill, panel board mill, post or pole mill. 

 This attribute is retained in this database for informational purposes but is 

intentionally left blank (null) because of the FIA data confidentiality policy. 

Users needing this type of information should contact the FIA Spatial Data 

Services (SDS) group by following the instructions provided at: 

http://www.fia.fs.fed.us/tools-data/spatial/. 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Condition Table 

50 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Code Description 

0 Land is not owned by industrial owner with wood processing plant 

1 Land is owned by industrial owner with wood processing plant 

 

 15. ADFORCD Administrative forest code. Identifies the administrative unit (Forest Service 

Region and National Forest) in which the condition is located. The first two 

digits of the four digit code are for the region number and the last two digits 

are for the Administrative National Forest number. Refer to appendix E for 

codes. Populated only for U.S. Forest Service lands OWNGRPCD = 10 and 

blank (null) for all other owners. 

 16. FORTYPCD Forest type code. This is the forest type used for reporting purposes. It is 

primarily derived using a computer algorithm, except when less than 25 

percent of the plot samples a particular forest condition. 

 Usually, FORTYPCD equals FORTYPCDCALC. In certain situations, 

however, the result from the algorithm (FORTYPCDCALC) is overridden by 

the field call. The field-recorded forest type code (FLDTYPCD) is stored in 

this attribute when less than 25 percent of the plot samples the forested 

condition (CONDPROP_UNADJ <0.25). 

 In most cases, FORTYPCD is the same as the field-recorded forest type 

(FLDTYPCD). However, situations of under sampling may cause this 

attribute to differ from FLDTYPCD. 

 Nonstocked forest land is land that currently has less than 10 percent 

stocking but formerly met the definition of forest land. Forest conditions 

meeting this definition have few, if any, trees sampled. In these instances, the 

algorithm cannot assign a specific forest type and the resulting forest type 

code is 999, meaning nonstocked. 

 Refer to appendix D for the complete list of forest type codes and names. 

 17. FLDTYPCD Field forest type code. Forest type, assigned by the field crew, based on the 

tree species or species groups forming a plurality of all live stocking. The 

field crew assesses the forest type based on the acre of forestland around the 

plot, in addition to the species sampled on the condition. Refer to appendix D 

for a detailed list of forest type codes and names. Nonstocked forest land is 

land that currently has less than 10 percent stocking but formerly met the 

definition of forest land. When PLOT.MANUAL <2.0, forest conditions that 

do not meet this stocking level were coded FLDTYPCD = 999. Beginning 

with manual version 2.0, the crew no longer recorded nonstocked as 999. 

Instead, they recorded FLDSZCD = 0 to identify nonstocked conditions and 

entered an estimated forest type for the condition. The crew determined the 

estimated forest type by either recording the previous forest type on 

remeasured plots or, on all other plots, the most appropriate forest type to the 

condition based on the seedlings present or the forest type of the adjacent 

forest stands. Periodic inventories will differ in the way FLDTYPCD was 

recorded – it is best to check with individual FIA work units for details. In 

general, when FLDTYPCD is used for analysis, it is necessary to examine the 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Condition Table 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 51

values of both FLDTYPCD and FLDSZCD to identify nonstocked forest 

land. 

 18. MAPDEN Mapping density. A code indicating the relative tree density of the condition. 

Codes other than 1 are used as an indication that a significant difference in 

tree density is the only factor causing another condition to be recognized and 

mapped on the plot. May be blank (null) for periodic inventories. 

Code Description 

1 Initial tree density class 

2 Density class 2 – density different than density of the condition assigned a tree 

density class of 1 

3 Density class 3 – density different than densities of the conditions assigned tree 

density classes of 1 and 2 

 19. STDAGE Stand age. For annual inventories (PLOT.MANUAL ≥1.0), stand age is equal 

to the field-recorded stand age (FLDAGE) with some exceptions. One 

exception is if FLDAGE = 999, then stand age is computed. When FLDAGE 

= 998, STDAGE is blank (null) because no trees were cored in the field. 

Another exception is that RMRS always computes stand age using fieldrecorded tree ages from trees in the calculated stand-size class. If no tree ages 

are available, then RMRS sets this attribute equal to FLDAGE. For all 

inventories, nonstocked stands have STDAGE set to 0. In periodic 

inventories, stand age is determined using local procedures. Annual inventory 

data will contain stand ages assigned to the nearest year. For some older 

inventories, stand age was set to 10-year classes for stands <100 years old, 

20-year age classes for stands between 100 and 200 years, and 100-year age 

classes if older than 200 years. These classes were converted to store the 

midpoint of the age class in years. Blank (null) values in the periodic data 

(PLOT.MANUAL <1.0) indicate that the stand was recorded as mixed age on 

forested condition classes. Age is difficult to measure and therefore 

STDAGE may have large measurement errors. 

 20. STDSZCD Stand-size class code. A classification of the predominant (based on 

stocking) diameter class of live trees within the condition assigned using an 

algorithm. Large diameter trees are at least 11.0 inches diameter for 

hardwoods and at least 9.0 inches diameter for softwoods. Medium diameter 

trees are at least 5.0 inches diameter and smaller than large diameter trees. 

Small diameter trees are <5.0 inches diameter. When <25 percent of the plot 

samples the forested condition (CONDPROP_UNADJ <0.25), this attribute 

is set to the equivalent field-recorded stand-size class (FLDSZCD). 

Populated for all forest annual plots, all forest periodic plots, and all NCRS 

periodic plots that were measured as “nonforest with trees” (e.g., wooded 

pasture, windbreaks). 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Condition Table 

52 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Code Description 

1 Large diameter – Stands with an all live stocking of at least 10 (base 100); 

with more than 50 percent of the stocking in medium and large diameter 

trees; and with the stocking of large diameter trees equal to or greater than the 

stocking of medium diameter trees 

2 Medium diameter – Stands with an all live stocking of at least 10 (base 100); 

with more than 50 percent of the stocking in medium and large diameter 

trees; and with the stocking of large diameter trees less than the stocking of 

medium diameter trees 

3 Small diameter – Stands with an all live stocking value of at least 10 (base 

100) on which at least 50 percent of the stocking is in small diameter trees 

5 Nonstocked – Forest land with all live stocking <10 

 

 21. FLDSZCD Field stand-size class code. Field-assigned classification of the predominant 

(based on stocking) diameter class of live trees within the condition. Blank 

(null) values may be present for periodic inventories. 

Code Description 

0 Nonstocked – Meeting the definition of accessible land and one of the 

following applies (1) <10 percent stocked by trees of any size, and not 

classified as cover trees (see code 6), or (2) for several western woodland 

species where stocking standards are not available, <5 percent crown cover 

of trees of any size. 

1 ≤4.9 inches (seedlings / saplings). At least 10 percent stocking (or 5 percent 

crown cover if stocking standards are not available) in trees of any size; and 

at least 2/3 of the crown cover is in trees <5.0 inches DBH/DRC. 

2 5.0 – 8.9 inches (softwoods)/ 5.0 – 10.9 inches (hardwoods). At least 

10 percent stocking (or 5 percent crown cover if stocking standards are not 

available) in trees of any size; and at least one-third of the crown cover is in 

trees ≥5.0 inches DBH/DRC and the plurality of the crown cover is in 

softwoods 5.0 – 8.9 inches diameter and/or hardwoods 5.0 –10.9 inches 

DBH, and/or for western woodland trees 5.0 – 8.9 inches DRC. 

3 9.0 – 19.9 inches (softwoods)/ 11.0 – 19.9 inches (hardwoods). At least 

10 percent stocking (or 5 percent crown cover if stocking standards are not 

available) in trees of any size; and at least one-third of the crown cover is in 

trees ≥5.0 inches DBH/DRC and the plurality of the crown cover is in 

softwoods 9.0 – 19.9 inches diameter and/or hardwoods between 

11.0 –19.9 inches DBH, and for western woodland trees 9.0 – 19.9 inches 

DRC. 

4 20.0 – 39.9 inches. At least 10 percent stocking (or 5 percent crown cover if 

stocking standards are not available) in trees of any size; and at least onethird of the crown cover is in trees ≥5.0 inches DBH/DRC and the plurality of 

the crown cover is in trees 20.0 – 39.9 inches DBH. 

5 40.0+ inches. At least 10 percent stocking (or 5 percent crown cover if 

stocking standards are not available) in trees of any size; and at least onethird of the crown cover is in trees ≥5.0 inches DBH/DRC and the plurality of 

the crown cover is in trees ≥40.0 inches DBH. 

6 Cover trees (trees not on species list, used for plots classified as nonforest): 

<10 percent stocking by trees of any size, and >5 percent crown cover of 

species that comprise cover trees. 

 22. SITECLCD Site productivity class code. A classification of forest land in terms of 

inherent capacity to grow crops of industrial wood. Identifies the potential 

growth in cubic feet/acre/year and is based on the culmination of mean 

annual increment of fully stocked natural stands. For data stored in the 

database that were processed outside of NIMS, this variable may be assigned 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Condition Table 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 53

based on the site productivity determined with the site trees, or from some 

other source, but the actual source of the site productivity class code is not 

known. For data processed with NIMS, this variable may either be assigned 

based on the site trees available for the plot, or, if no valid site trees are 

available, this variable is set equal to SITECLCDEST, a default value that is 

either an estimated or predicted site productivity class. If SITECLCDEST is 

used to populate SITECLCD, the variable SITECL_METHOD is set to 6. 

Code Description 

1 225+ cubic feet/acre/year 

2 165-224 cubic feet/acre/year 

3 120-164 cubic feet/acre/year 

4 85-119 cubic feet/acre/year 

5 50-84 cubic feet/acre/year 

6 20-49 cubic feet/acre/year 

7 0-19 cubic feet/acre/year 

 23. SICOND Site index for the condition. This represents the average total length in feet 

that dominant and co-dominant trees are expected to attain in well-stocked, 

even-aged stands at the specified base age (SIBASE). Site index is estimated 

for the condition by either using an individual tree or by averaging site index 

values that have been calculated for individual site trees (see 

SITETREE.SITREE) of the same species (SISP). As a result, it may be 

possible to find additional site index values that are not used in the 

calculation of SICOND in the SITETREE tables when site index has been 

calculated for more than one species in a condition. This attribute is blank 

(null) when no site index data are available. 

 24. SIBASE Site index base age. The base age (sometimes called reference age), in years, 

of the site index curve used to derive site index. Base age may be breast 

height age or total age, depending on the specifications of the site index 

curves being used. This attribute is blank (null) when no site tree data are 

available. 

 25. SISP Site index species code. The species upon which the site index is based. In 

most cases, the site index species will be one of the species that define the 

forest type of the condition (FORTYPCD). In cases where there are no 

suitable site trees of the type species, other suitable species may be used. This 

attribute is blank (null) when no site tree data are available. 

 26. STDORGCD Stand origin code. Method of stand regeneration for the trees in the 

condition. An artificially regenerated stand is established by planting or 

artificial seeding. Populated for all forest annual plots, all forest periodic 

plots, and all NCRS periodic plots that were measured as “nonforest with 

trees” (e.g., wooded pasture, windbreaks). 

Code Description 

0 Natural stands 

1 Clear evidence of artificial regeneration 

 
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Chapter 3. Condition Table 

54 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 27. STDORGSP Stand origin species code. The species code for the predominant artificially 

regenerated species (only when STDORGCD = 1). See appendix F. May not 

be populated for some FIA work units when PLOT.MANUAL <1.0. 

 28. PROP_BASIS Proportion basis. A value indicating what type of fixed-size subplots were 

installed when this plot was sampled. This information is needed to use the 

proper adjustment factor for the stratum in which the plot occurs (see 

POP_STRATUM.ADJ_FACTOR_SUBP and 

POP_STRATUM.ADJ_FACTOR_MACR.) Usually 24-foot radius subplots 

are installed and in this case, the value for PROP_BASIS is “SUBP.” 

However, when 58.9-foot radius macroplots are installed, the value is 

“MACR.” This attribute is blank (null) for periodic inventories. 

 29. CONDPROP_UNADJ 

 Condition proportion unadjusted. The unadjusted proportion of the plot that 

is in the condition. This variable is retained for ease of area calculations. It is 

equal to either SUBPPROP_UNADJ or MACRPROP_UNADJ, depending 

on the value of PROP_BASIS. The sum of all condition proportions for a plot 

equals 1. When generating population area estimates, this proportion is 

adjusted by either the POP_STRATUM.ADJ_FACTOR_MACR or the 

POP_STRATUM.ADJ_FACTOR_SUBP to account for partially nonsampled 

plots (access denied or hazardous portions). 

 30. MICRPROP_UNADJ 

 Microplot proportion unadjusted. The unadjusted proportion of the 

microplots that are in the condition. The sum of all microplot condition 

proportions for a plot equals 1. 

 31. SUBPPROP_UNADJ 

 Subplot proportion unadjusted. The unadjusted proportion of the subplots 

that are in the condition. The sum of all subplot condition proportions for a 

plot equals 1. 

 32. MACRPROP_UNADJ 

 Macroplot proportion unadjusted. The unadjusted proportion of the 

macroplots that are in the condition. When macroplots are installed, the sum 

of all macroplot condition proportions for a plot equals 1; otherwise this 

attribute is left blank (null). 

 33. SLOPE Slope. The angle of slope, in percent, of the condition. Valid values are 000 

through 155 for data collected when PLOT.MANUAL ≥1.0, and 000 through 

200 on data collected when PLOT.MANUAL <1.0. When PLOT.MANUAL 

<1.0, the field crew measured condition slope by sighting along the average 

incline or decline of the condition. When PLOT.MANUAL ≥1.0, slope is 

collected on subplots but no longer collected for conditions. When 

PLOT.MANUAL ≥1.0, the slope from the subplot representing the greatest 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Condition Table 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 55

percentage of the condition is assigned as a surrogate. In the event that two or 

more subplots represent the same amount of area in the condition, the slope 

from the lower numbered subplot is used. Populated for all forest annual 

plots, all forest periodic plots, and all NCRS periodic plots that were 

measured as “nonforest with trees” (e.g., wooded pasture, windbreaks). 

 34. ASPECT Aspect. The direction of slope, to the nearest degree, for most of the 

condition. North is recorded as 360. When slope is <5 percent, there is no 

aspect and this item is set to zero. When PLOT.MANUAL <1.0, the field 

crew measured condition aspect. When PLOT.MANUAL ≥1.0, aspect is 

collected on subplots but no longer collected for conditions. NOTE: for plots 

measured when PLOT.MANUAL ≥1.0, the aspect from the subplot 

representing the greatest percentage of the condition is assigned as a 

surrogate. In the event that two or more subplots represent the same 

percentage of area in the condition, the slope from the lower numbered 

subplot is used. Populated for all forest annual plots, all forest periodic plots, 

and all NCRS periodic plots that were measured as “nonforest with trees” 

(e.g., wooded pasture, windbreaks). 

 35. PHYSCLCD Physiographic class code. The general effect of land form, topographical 

position, and soil on moisture available to trees. These codes are new in 

annual inventory; older inventories have been updated to these codes when 

possible. Also populated for the NCRS periodic plots that were measured as 

“nonforest with trees” (e.g., wooded pasture, windbreaks). 

Code Description 

Xeric sites (normally low or deficient in available moisture) 

11 Dry Tops – Ridge tops with thin rock outcrops and considerable exposure to 

sun and wind. 

12 Dry Slopes – Slopes with thin rock outcrops and considerable exposure to 

sun and wind. Includes most mountain/steep slopes with a southern or 

western exposure. 

13 Deep Sands – Sites with a deep, sandy surface subject to rapid loss of 

moisture following precipitation. Typical examples include sand hills, ridges, 

and flats in the South, sites along the beach and shores of lakes and streams. 

19 Other Xeric – All dry physiographic sites not described above. 

 

Mesic sites (normally moderate but adequate available moisture) 

21 Flatwoods – Flat or fairly level sites outside of flood plains. Excludes deep 

sands and wet, swampy sites. 

22 Rolling Uplands – Hills and gently rolling, undulating terrain and associated 

small streams. Excludes deep sands, all hydric sites, and streams with 

associated flood plains. 

23 Moist Slopes and Coves – Moist slopes and coves with relatively deep, fertile 

soils. Often these sites have a northern or eastern exposure and are partially 

shielded from wind and sun. Includes moist mountain tops and saddles. 

24 Narrow flood plains/Bottomlands – Flood plains and bottomlands less than 

1/4-mile in width along rivers and streams. These sites are normally well 

drained but are subjected to occasional flooding during periods of heavy or 

extended precipitation. Includes associated levees, benches, and terraces 

within a 1/4 mile limit. Excludes swamps, sloughs, and bogs. 
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Chapter 3. Condition Table 

56 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Code Description 

25 Broad Floodplains/Bottomlands – Floodplains and bottomlands 1⁄4 mile or 

wider along rivers and streams. These sites are normally well drained but are 

subjected to occasional flooding during periods of heavy or extended 

precipitation. Includes associated levees, benches, and terraces. Excludes 

swamps, sloughs, and bogs with year-round water problems. 

29 Other Mesic – All moderately moist physiographic sites not described above. 

 

Hydric sites (normally abundant or overabundant moisture all year) 

31 Swamps/Bogs – Low, wet, flat, forested areas usually quite extensive that are 

flooded for long periods except during periods of extreme drought. Excludes 

cypress ponds and small drains. 

32 Small Drains – Narrow, stream-like, wet strands of forest land often without a 

well-defined stream channel. These areas are poorly drained or flooded 

throughout most of the year and drain the adjacent higher ground. 

33 Bays and wet pocosins – Low, wet, boggy sites characterized by peaty or 

organic soils. May be somewhat dry during periods of extended drought. 

Examples include sites in the Carolina bays in the Southeast United States. 

34 Beaver ponds. 

35 Cypress ponds. 

39 Other hydric – All other hydric physiographic sites. 

 

 36. GSSTKCD Growing-stock stocking code. A code indicating the stocking of the condition 

by growing-stock trees, including seedlings. Growing-stock trees are those 

where tree class (TREE.TREECLCD) equals 2 or, for seedlings that do not 

have tree class assigned where species group (TREE.SPGRPCD) is not equal 

to 23 (western woodland softwoods), 43 (eastern noncommercial 

hardwoods), and 48 (western woodland hardwoods). Populated for all forest 

annual plots, all forest periodic plots, and all NCRS periodic plots that were 

measured as “nonforest with trees” (e.g., wooded pasture, windbreaks). 

Code Description 

1 Overstocked (100+ %) 

2 Fully stocked (60 – 99%) 

3 Medium stocked (35 – 59%) 

4 Poorly stocked (10 – 34%) 

5 Nonstocked ( 0 – 9%) 

 

 37. ALSTKCD All live stocking code. A code indicating the stocking of the condition by live 

trees, including seedlings. Data are in classes as listed for GSSTKCD above. 

May not be populated for some FIA work units when PLOT.MANUAL <1.0. 

Populated for all forest annual plots, all forest periodic plots, and all NCRS 

periodic plots that were measured as “nonforest with trees” (e.g., wooded 

pasture, windbreaks). 

 38. DSTRBCD1 Disturbance 1 code. A code indicating the kind of disturbance occurring 

since the last measurement or within the last 5 years for new plots. The area 

affected by the disturbance must be at least 1 acre in size. A significant level 

of disturbance (mortality or damage to 25 percent of the trees in the 

condition) is required. Populated for all forested conditions using the 

National Field Guide protocols (PLOT.MANUAL ≥1.0) and populated by 

some FIA work units where PLOT.MANUAL <1.0. Codes 11, 12, 21, and 22 

are valid where PLOT. MANUAL ≥2.0. 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Condition Table 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 57

Code Description 

0 No visible disturbance 

10 Insect Damage 

 11 Insect damage to understory vegetation 

 12 Insect damage to trees, including seedlings and saplings 

20 Disease Damage 

 21 Disease damage to understory vegetation 

 22 Disease damage to trees, including seedlings and saplings 

30 Fire damage (from crown and ground fire, either prescribed or natural) 

 31 Ground fire damage 

 32 Crown fire damage 

40 Animal Damage 

 41 Beaver (includes flooding caused by beaver) 

 42 Porcupine 

 43 Deer/ungulate 

 44 Bear (CORE OPTIONAL) 

 45 Rabbit (CORE OPTIONAL) 

 46 Domestic animal/livestock (includes grazing) 

50 Weather Damage 

 51 Ice 

 52 Wind (includes hurricane, tornado) 

 53 Flooding (weather induced) 

 54 Drought 

60 Vegetation (suppression, competition, vines) 

70 Unknown / not sure / other (include in NOTES) 

80 Human-caused damage – any significant threshold of human-caused damage 

not described in the DISTURBANCE codes or in the TREATMENT codes. 

90 Geologic disturbances 

 91 Landslide 

 92 Avalanche track 

 93 Volcanic blast zone 

 94 Other geologic event 

 95 Earth movement / avalanches 

 

 39. DSTRBYR1 Disturbance year 1. Year in which Disturbance 1 is estimated to have 

occurred. If the disturbance occurs continuously over a period of time, the 

value 9999 is used. Populated for all forested conditions that have some 

disturbance using the National Field Guide protocols (PLOT.MANUAL ≥1.0) 

and populated by some FIA work units where PLOT.MANUAL <1.0. If 

DISTRBCD1 = 0 then DSTRBYR1 = blank (null) or 0. 

 40. DSTRBCD2 Disturbance 2 code. The second disturbance code, if the stand has 

experienced more than one disturbance. See DSTRBCD1 for more 

information. This attribute is new in annual inventory. 

 41. DSTRBYR2 Disturbance year 2. The year in which Disturbance 2 occurred. See 

DSTRBYR1 for more information. This attribute is new in annual inventory. 

 42. DSTRBCD3 Disturbance 3 code. The third disturbance code, if the stand has experienced 

more than two disturbances. See DSTRBCD1 for more information. This 

attribute is new in annual inventory. 

 43. DSTRBYR3 Disturbance year 3. The year in which Disturbance 3 occurred. See 

DSTRBYR1 for more information. This attribute is new in annual inventory. 
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58 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 44. TRTCD1 Treatment code 1. A code indicating the type of stand treatment that has 

occurred since the last measurement or within the last 5 years for new plots. 

The area affected by the treatment must be at least 1 acre in size. Populated 

for all forested conditions using the National Field Guide protocols 

(PLOT.MANUAL ≥1.0) and populated by some FIA work units where 

PLOT.MANUAL <1.0. When PLOT.MANUAL <1.0, inventories may 

record treatments occurring within the last 20 years for new plots. 

Code Description 

00 No observable treatment. 

10 Cutting – The removal of one or more trees from a stand. 

20 Site preparation – Clearing, slash burning, chopping, disking, bedding, or other 

practices clearly intended to prepare a site for either natural or artificial 

regeneration. 

30 Artificial regeneration – Following a disturbance or treatment (usually cutting), 

a new stand where at least 50 percent of the live trees present resulted from 

planting or direct seeding. 

40 Natural regeneration – Following a disturbance or treatment (usually cutting), a 

new stand where at least 50 percent of the live trees present (of any size) were 

established through the growth of existing trees and/or natural seeding or 

sprouting. 

50 Other silvicultural treatment – The use of fertilizers, herbicides, girdling, 

pruning, or other activities (not covered by codes 10-40) designed to improve 

the commercial value of the residual stand, or chaining, which is a practice used 

on western woodlands to encourage wildlife forage. 

 45. TRTYR1 Treatment year 1. Year in which Stand Treatment 1 is estimated to have 

occurred. Populated for all forested conditions that have some treatment 

using the National Field Guide protocols (PLOT.MANUAL ≥1.0) and 

populated by some FIA work units where PLOT.MANUAL <1.0. If 

TRTCD1 = 00 then TRTYR1 = blank (null) or 0. 

 46. TRTCD2 Treatment code 2. A code indicating the type of stand treatment that has 

occurred since the last measurement or within the last 5 years for new plots. 

See TRTCD1 for more information. 

 47. TRTYR2 Treatment year 2. Year in which Stand Treatment 2 is estimated to have 

occurred. See TRTYR1 for more information. 

 48. TRTCD3 Treatment code 3. A code indicating the type of stand treatment that has 

occurred since the last measurement or within the last 5 years for new plots. 

See TRTCD1 for more information. 

 49. TRTYR3 Treatment year 3. Year in which Stand Treatment 3 is estimated to have 

occurred. See TRTYR1 for more information. 

 50. PRESNFCD Present nonforest code. (Core for remeasured conditions that were forest 

before and are now nonforest; Core optional for all conditions where current 

condition class status is nonforest, regardless of the previous condition.) A 

code indicating the current nonforest land use for conditions that were 

previously classified as forest but are now classified as nonforest. This 

attribute can be optionally recorded for all nonforest conditions, regardless of 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 59

either past land status or whether the condition has a previous measurement.

May be populated when PLOT.MANUAL <1.0. 

Code Description 

10 Agricultural land 

11 Cropland 

12 Pasture (improved through cultural practices) 

13 Idle farmland 

14 Orchard 

15 Christmas tree plantation 

16 Maintained wildlife opening* 

17 Windbreak/Shelterbelt* 

20 Rangeland 

30 Developed 

31 Cultural (business, residential, other intense human activity) 

32 Rights-of-way (improved road, railway, power line) 

33 Recreation (park, golf course, ski run) 

34 Mining* 

40 Other (undeveloped beach, marsh, bog, snow, ice) 

41 Nonvegetated* 

42 Wetland* 

43 Beach* 

45 Nonforest-Chaparral* 

*These codes are currently regional. They will become national in PLOT.MANUAL = 5.0. 

 51. BALIVE Basal area of live trees. Basal area in square feet per acre of all live trees over 

1 inch DBH/DRC sampled in the condition. 

 52. FLDAGE Field-recorded stand age. The stand age as assigned by the field crew. Based 

on the average total age, to the nearest year, of the trees in the field-recorded 

stand-size class of the condition, determined using local procedures. For nonstocked stands, 0 is stored. If all of the trees in a condition class are of a 

species that by regional standards cannot be bored for age (e.g., mountain 

mahogany, tupelo), 998 is recorded. If tree cores are not counted in the field, 

but are collected and sent to the office for the counting of rings, 999 is 

recorded. 

 53. ALSTK All-live-tree stocking percent. The sum of stocking percent values of all live 

trees on the condition. The percent is then assigned to a stocking class, which 

is found in ALSTKCD. May not be populated for some FIA work units when 

PLOT.MANUAL <1.0. 

 54. GSSTK Growing-stock stocking percent. The sum of stocking percent values of all 

growing-stock trees on the condition. The percent is then assigned to a 

stocking class, which is found in GSSTKCD. May not be populated for some 

FIA work units when PLOT.MANUAL <1.0. 

 55. FORTYPCDCALC 

 Forest type code calculated. Forest type is always calculated based on the tree 

species sampled on the condition. The forest typing algorithm is a 

hierarchical procedure applied to the tree species sampled on the condition. 

The algorithm begins by comparing the live tree stocking of softwoods and 
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60 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

hardwoods and continues in a stepwise fashion comparing successively 

smaller subgroups of the preceding aggregation of initial type groups, 

selecting the group with the largest aggregate stocking value. The 

comparison proceeds in most cases until a plurality of a forest type is 

identified. 

 Nonstocked forest land is land that currently has less than 10 percent 

stocking but formerly met the definition of forest land. Forest conditions 

meeting this definition have few, if any, trees sampled. In these instances, the 

algorithm cannot assign a specific forest type and the resulting forest type 

code is 999, meaning nonstocked. See also FORTYPCD and FLDTYPCD for 

other forest type attributes. Refer to appendix D for a complete list of forest 

type codes and names. 

 56. HABTYPCD1 Habitat type code 1. A code indicating the primary habitat type (or 

community type) for this condition. Unique codes are determined by 

combining both habitat type code and publication code (HABTYPCD1 and 

HABTYPCD1_PUB_CD). Habitat type captures information about both the 

overstory and understory vegetation and usually describes the vegetation that 

is predicted to become established after all successional stages of the 

ecosystem are completed without any disturbance. This code can be 

translated using the publication in which it was named and described (see 

HABTYPCD1_PUB_CD and HABTYPCD1_DESCR_PUB_CD). Only 

collected by certain FIA work units (SURVEY.RSCD = 22, 23, or 26). 

 57. HABTYPCD1_PUB_CD 

Habitat type code 1 publication code. A code indicating the publication that 

lists the name for the habitat type code (HABTYPCD1). Publication 

information is documented in the REF_HABTYP_PUBLICATION table. 

Only used by certain FIA work units (SURVEY.RSCD = 22, 23, or 26). 

 58. HABTYPCD1_DESCR_PUB_CD 

Habitat type code 1 description publication code. A code indicating the 

publication that gives a description for habitat type code 1 (HABTYPCD1). 

This publication may or may not be the same publication that lists the name 

of the habitat type (HABTYPCD1_PUB_CD). Publication information is 

documented in REF_HABTYP_PUBLICATION table. Only used by certain 

FIA work units (SURVEY.RSCD = 22, 23, or 26). 

 59. HABTYPCD2 Habitat type code 2. A code indicating the secondary habitat type (or 

community type) for this condition. Unique codes are determined by 

combining both habitat type code and publication code (HABTYPCD2 and 

HABTYPCD2_PUB_CD). Habitat type captures information about both the 

overstory and understory vegetation and usually describes the vegetation that 

is predicted to become established after all successional stages of the 

ecosystem are completed without any disturbance. This code can be 

translated using the publication in which it was named and described (see 
FIA Database Description and Users Manual for Phase 2, version 4.0 

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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 61

HABTYPCD2_PUB_CD and HABTYPCD2_DESCR_PUB_CD). Only 

collected by certain FIA work units (SURVEY.RSCD = 22, 23, or 26). 

 60. HABTYPCD2_PUB_CD 

Habitat type code 2 publication code. A code indicating the publication that 

lists the name for the habitat type code (HABTYPCD2). Publication 

information is documented in REF_HABTYP_PUBLICATION table. Only 

used by certain FIA work units (SURVEY.RSCD = 22, 23, or 26). 

 61. HABTYPCD2_DESCR_PUB_CD 

Habitat type code 2 description publication code. A code indicating the 

publication that gives a description for habitat type code 2 (HABTYPCD2). 

This publication may or may not be the same publication that lists the name 

of the habitat type (HABTYPCD2_PUB_CD). Publication information is 

documented in REF_HABTYP_PUBLICATION table. Only used by certain 

FIA work units (SURVEY.RSCD = 22, 23, or 26). 

 62. MIXEDCONFCD 

 Mixed conifer site code. An indicator to show that the forest condition is a 

mixed conifer site in California. These sites are a complex association of 

ponderosa pine, sugar pine, Douglas-fir, white fir, red fir, and/or incensecedar. Mixed conifer sites use a specific site index equation.This is a yes/no 

attribute. This attribute is left blank (null) for all other States. Only collected 

by certain FIA work units (SURVEY.RSCD = 26). 

Code Description 

Y Yes, the condition is a mixed conifer site in California 

N No, the condition is not a mixed conifer site in California 

 63. VOL_LOC_GRP 

 Volume location group. An identifier indicating what equations are used for 

volume, biomass, site index, etc. A volume group is usually designated for a 

geographic area, such as a State, multiple States, a group of counties, or an 

ecoregion. 

Code Description 

S22LAZN Northern Arizona Ecosections 

S22LAZS Southern Arizona Ecosections 

S22LCOE Eastern Colorado Ecosections 

S22LCOW Western Colorado Ecosections 

S22LID Idaho Ecosections 

S22LMTE Eastern Montana Ecosections 

S22LMTW Western Montana Ecosections 

S22LNV Nevada Ecosections 

S22LNMN Northern New Mexico Ecosections 

S22 LNMS Southern New Mexico Ecosections 
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62 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Code Description 

S22LUTNE Northern & Eastern Utah Ecosections 

S22LUTSW Southern & Western Utah Ecosections 

S22LWYE Eastern Wyoming Ecosections 

S22LWYW Western Wyoming Ecosections 

S23LCS Central States (IL, IN, IW, MO) 

S23LLS Lake States (MI, MN, WI) 

S23LPS Plains States (KS, NE, ND, SD) 

S24 Northeastern States (CT, DE, ME, MD, MA, NH, NJ, NY, OH, PA, RI, VT, WV) 

S26LCA California other than mixed conifer forest type 

S26LCAMIX California mixed conifer forest type 

S26LEOR Eastern Oregon 

S26LEWA Eastern Washington 

S26LORJJ Oregon Jackson and Josephine Counties 

S26LWOR Western Oregon 

S26LWWA Western Washington 

S26LWACF Washington Silver Fir Zone 

S27LAK1A Coastal Alaska Southeast 

S27LAK1AB Coastal Alaska Southeast and Central 

S27LAK1B Coastal Alaska Central 

S27LAK1C Coastal Alaska Kodiak and Afognak Islands 

S33 Southern Research States (excluding Puerto Rico and the Virgin Islands) – AL, AR, 

FL, GA, LA, KY, MS, OK, NC, SC, TN, TX, VA 

S33PRVI Puerto Rico and Virgin Islands 

 64. SITECLCDEST 

 Site productivity class code estimated. This is a field-recorded code that is an 

estimated or predicted indicator of site productivity. It is used as the value for 

SITECLCD if no valid site tree is available. When SITECLCDEST is used as 

SITECLCD, SITECL_METHOD is set to 6. For data stored in the database 

that were processed prior to the use of NIMS, this variable is blank (null). 

Only collected by certain FIA work units (SURVEY.RSCD = 24, 26, 27 or 

33). 

Code Description 

1 225+ cubic feet/acre/year 

2 165-224 cubic feet/acre/year 

3 120-164 cubic feet/acre/year 

4 85-119 cubic feet/acre/year 

5 50-84 cubic feet/acre/year 

6 20-49 cubic feet/acre/year 

7 0-19 cubic feet/acre/year 

 65. SITETREE_TREE 

 Site tree tree number. If an individual site index tree is used to calculate 

SICOND, this is the tree number of the site tree (SITETREE.TREE column) 

used. Only collected by certain FIA work units (SURVEY.RSCD = 23 or 

33). 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 63

 66. SITECL_METHOD 

 Site class method. A code identifying the method for determining site index 

or estimated site productivity class. 

Code Description 

1 Tree measurement (length, age, etc.) collected during this inventory. 

2 Tree measurement (length, age, etc.) collected during a previous inventory. 

3 Site index or site productivity class estimated either in the field or office. 

4 Site index or site productivity class estimated by the height intercept method 

during this inventory. 

5 Site index or site productivity class estimated using multiple site trees. 

6 Site index or site productivity class estimated using default values. 

 67. CARBON_DOWN_DEAD 

 Carbon in down dead. Carbon (tons per acre) of woody material >3 inches in 

diameter on the ground, and stumps and their roots >3 inches in diameter. 

Estimated from models based on geographic area, forest type, and live tree 

carbon density (Smith and Heath 2008). This modeled attribute is a 

component of the EPA’s Greenhouse Gas Inventory and is not a direct sum of 

Phase 2 or Phase 3 measurements. This is a per acre estimate and must be 

multiplied by the appropriate expansion and condition proportion adjustment 

factor located in the POP_STRATUM table. 

 68. CARBON_LITTER 

 Carbon in litter. Carbon (tons per acre) of organic material on the floor of the 

forest, including fine woody debris, humus, and fine roots in the organic 

forest floor layer above mineral soil. Estimated from models based on 

geographic area, forest type, and (except for nonstocked and pinyon-juniper 

stands) stand age (Smith and Heath 2002). This modeled attribute is a 

component of the EPA’s Greenhouse Gas Inventory and is not a direct sum of 

Phase 2 or Phase 3 measurements. This is a per acre estimate and must be 

multiplied by the appropriate expansion and condition proportion adjustment 

factor located in the POP_STRATUM table. 

 69. CARBON_SOIL_ORG 

 Carbon in organic soil. Carbon (tons per acre) in fine organic material below 

the soil surface to a depth of 1 meter. Does not include roots. Estimated from 

models based on geographic area and forest type (Smith and Heath 2008). 

This modeled attribute is a component of the EPA’s Greenhouse Gas 

Inventory and is not a direct sum of Phase 2 or Phase 3 measurements. This is 

a per acre estimate and must be multiplied by the appropriate expansion and 

condition proportion adjustment factor located in the POP_STRATUM table. 

 70. CARBON_STANDING_DEAD 

 Carbon in standing dead. Carbon (tons per acre) in standing dead trees, 

including coarse roots, is estimated from models based on geographic area, 
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64 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

forest type, and (except for nonstocked stands) growing stock volume (Smith 

and Heath 2008). This modeled variable is a component of the EPA’s 

Greenhouse Gas Inventory and is not a direct sum of Phase 2 or Phase 3 

measurements. For most users it is preferable to calculate carbon (tons per 

acre) for annual inventories from the Phase 2 tree data. This is a per acre 

estimate and must be multiplied by the appropriate expansion and condition 

proportion adjustment factor located in the POP_STRATUM table. 

 71. CARBON_UNDERSTORY_AG 

 Carbon in understory aboveground. Carbon (tons per acre) in the 

aboveground portions of seedlings, shrubs, and bushes. Estimated from 

models based on geographic area, forest type, and (except for nonstocked and 

pinyon-juniper stands) live tree carbon density (Smith and Health 2008). This 

modeled attribute is a component of the EPA’s Greenhouse Gas Inventory 

and is not a direct sum of Phase 2 or Phase 3 measurements. This is a per acre 

estimate and must be multiplied by the appropriate expansion and condition 

proportion adjustment factor located in the POP_STRATUM table. 

 72. CARBON_UNDERSTORY_BG 

 Carbon in understory belowground. Carbon (tons per acre) in the 

belowground portions of seedlings, shrubs, and bushes. Estimated from 

models based on geographic area, forest type, and (except for nonstocked and 

pinyon-juniper stands) live tree carbon density (Smith and Heath 2008). This 

modeled attribute is a component of the EPA’s Greenhouse Gas Inventory 

and is not a direct sum of Phase 2 or Phase 3 measurements. This is a per acre 

estimate and must be multiplied by the appropriate expansion and condition 

proportion adjustment factor located in the POP_STRATUM table. 

 73. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 74. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 75. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 76. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 
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 77. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 78. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 

 79. CYCLE Inventory cycle number. A number assigned to a set of plots, measured over 

a particular period of time from which a State estimate using all possible 

plots is obtained. A cycle number >1 does not necessarily mean that 

information for previous cycles resides in the database. A cycle is relevant 

for periodic and annual inventories. 

 80. SUBCYCLE Inventory subcycle number. For an annual inventory that takes n years to 

measure all plots, subcycle shows in which of the n years of the cycle the 

data were measured. Subcycle is 0 for a periodic inventory. Subcycle 99 may 

be used for plots that are not included in the estimation process. 

 81. SOIL_ROOTING_DEPTH_PNW 

Soil rooting depth, Pacific Northwest Research Station. Describes the soil depth 

(the depth to which tree roots can penetrate) within each forest land condition 

class. Required for all forest condition classes. This variable is coded 1 when 

more than half of area in the condition class is estimated to be ≤20 inches deep. 

Ground pumice, decomposed granite, and sand all qualify as types of soil. Only 

collected by certain FIA work units (SURVEY.RSCD = 26). 

Code Description 

1 ≤20 inches 

2 >20 inches 

 82. GROUND_LAND_CLASS_PNW 

 Present ground land class, Pacific Northwest Research Station. A refinement 

of forest land that distinguishes timberland and a variety of forest land types. 

Each code, and corresponding ground land class (GLC) name and description 

are listed. Only collected by certain FIA work units (SURVEY.RSCD = 26). 

Code Description 

120 Timberland – Forest land that is potentially capable of producing at least 

20 cubic feet/acre/year at culmination in fully stocked, natural stands 

(1.4 cubic meters/hectare/year) of continuous crops of trees to industrial 

roundwood size and quality. Industrial roundwood requires species that grow to 

size and quality adequate to produce lumber and other manufactured products 

(exclude fence posts and fuel wood that are not considered manufactured). 

Timberland is characterized by no severe limitations on artificial or natural 

restocking with species capable of producing industrial roundwood. 
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66 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Code Description 

141 Other forest rocky – Other forest land that can produce tree species of industrial 

roundwood size and quality, but that is unmanageable because the site is steep, 

hazardous, and rocky, or is predominantly nonstockable rock or bedrock, with 

trees growing in cracks and pockets. Other forest-rocky sites may be incapable of 

growing continuous crops due to inability to obtain adequate regeneration 

success. 

142 Other forest unsuitable site (wetland, subalpine, or coastal conifer scrub; 

California only) – Other forest land that is unsuited for growing industrial 

roundwood because of one of the following environment factors: willow bogs, 

spruce bogs, sites with high water tables or even standing water for a portion of 

the year, and harsh sites due to extreme climatic and soil conditions. Trees present 

are often extremely slow growing and deformed. Examples: whitebark pine, 

lodgepole, or mountain hemlock stands at timberline; shore pine along the 

sparkling blue Pacific Ocean (Monterey, Bishop, and Douglas-fir); willow 

wetlands with occasional cottonwoods present; Sitka spruce-shrub communities 

bordering tidal flats and channels along the coast. Includes aspen stands in highdesert areas or areas where juniper/mountain mahogany are the predominant 

species. 

143 Other forest pinyon-juniper – Areas currently capable of 10 percent or more tree 

stocking with forest trees, with juniper species predominating. These areas are not 

now, and show no evidence of ever having been,10 percent or more stocked with 

trees of industrial roundwood form and quality. Stocking capabilities indicated by 

live juniper trees or juniper stumps and juniper snags less than 25 years dead or 

cut. Ten percent juniper stocking means 10 percent crown cover at stand maturity. 

For western woodland juniper species, ten percent stocking means 5 percent 

crown cover at stand maturity. 

144 Other forest-oak (formally oak woodland) – Areas currently 10 percent or more 

stocked with forest trees, with low quality forest trees of oak, gray pine, madrone, 

or other hardwood species predominating, and that are not now, and show no 

evidence of ever having been, 10 percent or more stocked with trees of industrial 

roundwood form and quality. Trees on these sites are usually short, slow growing, 

gnarled, poorly formed, and generally suitable only for fuel wood. The following 

types are included: blue oak, white oak, live oak, oak-gray pine. 

146 Other forest unsuitable site (Oregon and Washington only) – Other forest land 

that is unsuited for growing industrial roundwood because of one of the following 

environment factors: willow bogs, spruce bogs, sites with high water tables or 

even standing water for a portion of the year, and harsh sites due to climatic 

conditions. Trees present are often extremely slow growing and deformed. 

Examples: whitebark pine or mountain hemlock stands at timberline, shore pine 

along the Pacific Ocean, willow wetlands with occasional cottonwoods present, 

and Sitka spruce-shrub communities bordering tidal flats and channels along the 

coast. Aspen stands in high-desert areas or areas where juniper/mountain 

mahogany are the predominant species are considered other forest-unsuitable site. 

148 Other forest-Cypress (California only) – Forest land with forest trees with cypress 

predominating. Shows no evidence of having had 10 percent or more cover of 

trees of industrial roundwood quality and species. 

149 Other forest-Low Productivity (this code is calculated in the office) – Forestland 

capable of growing crops of trees to industrial roundwood quality, but not able to 

grow wood at the rate of 20 cubic feet/acre/year. Included are areas of low 

stocking potential and/or very low site index. 

150 Other forest curlleaf mountain mahogany – Areas currently capable of 10 percent 

or more tree stocking with forest trees, with curlleaf mountain mahogany species 

predominating. These areas are not now, and show no evidence of ever having 

been, 10 percent or more stocked with trees of industrial roundwood form and 

quality; 10 percent mahogany stocking means 5 percent crown cover at stand 

maturity. 
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 83. PLANT_STOCKABILITY_FACTOR_PNW 

Plant stockability factor, Pacific Northwest Research Station. Some plots in 

PNWRS have forest land condition classes that are low site, and are 

incapable of attaining normal yield table levels of stocking. For such classes, 

potential productivity (mean annual increment at culmination) must be 

discounted. Most forested conditions have a default value of 1 assigned; 

those conditions that meet the low site criteria have a value between 0.1 and 

1. Key plant indicators and plant communities are used to assign discount 

factors, using procedures outlined in MacLean and Bolsinger (1974) and 

Hanson and others (2002). Only collected by certain FIA work units 

(SURVEY.RSCD = 26). 

 84. STND_COND_CD_PNWRS 

 Stand condition code, Pacific Northwest Research Station. A code that best 

describes the condition of the stand within forest condition classes. Stand 

condition is defined here as “ the size, density, and species composition of a 

plant community following disturbance and at various time intervals after 

disturbance.” Information on stand condition is used in describing wildlife 

habitat. Only collected by certain FIA work units (SURVEY.RSCD = 26). 

Code Stand Condition Definition 

0 Not applicable Condition class is juniper, chaparral, or curlleaf 

mountain mahogany forest type. 

1 Grass-forb Shrubs <40 percent crown cover and <5 feet tall; plot 

may range from being largely devoid of vegetation to 

dominance by herbaceous species (grasses and forbs); 

tree regeneration generally <5 feet tall and 40 percent 

cover. 

2 Shrub Shrubs 40 percent crown canopy or greater, of any 

height; trees <40 percent crown canopy and <1.0 inch 

DBH/DRC. When average stand diameter exceeds 

1.0 inch DBH/DRC, plot is “open sapling” or “closed 

sapling.” 

3 Open sapling, 

poletimber 

Average stand diameter 1.0-8.9 inches DBH/DRC, and 

tree crown canopy poletimber <60 percent. 

4 Closed sapling, pole, 

sawtimber 

Average stand diameter is 1.0-21.0 inches DBH/DRC 

and crown cover is 60 percent or greater. 

5 Open sawtimber Average stand diameter is 9.0-21.0 inches DBH/DRC, 

and crown cover is <60 percent. 

6 Large sawtimber Average stand diameter exceeds 21.0 inches 

DBH/DRC; crown cover may be <100 percent; decay 

and decadence required for old-growth characteristics 

is generally lacking, successional trees required by oldgrowth may be lacking, and dead and down material 

required by old-growth is lacking. 

7 Old-growth Average stand diameter exceeds 21.0 inches 

DBH/DRC. Stands over 200 years old with at least two 

tree layers (overstory and understory), decay in living 

trees, snags, and down woody material. Some of the 

overstory layer may be composed of long-lived 

successional species (i.e., Douglas-fir, western 

redcedar). 
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68 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 85. STND_STRUC_CD_PNWRS 

 Stand structure code, Pacific Northwest Research Station. A code indicating 

the best overall structure of the stand. Only collected by certain FIA work 

units (SURVEY.RSCD = 26). 

Code Stand Structure Definition 

1 Even-aged singlestoried 

A single even canopy characterizes the stand. The 

greatest numbers of trees are in a height class represented 

by the average height of the stand; there are substantially 

fewer trees in height classes above and below this mean. 

The smaller trees are usually tall spindly members that 

have fallen behind their associates. The ages of trees 

usually do not differ by more than 20 years. 

2 Even-aged twostoried 

Stands composed of two distinct canopy layers, such as, 

an overstory with an understory sapling layer possibly 

from seed tree and shelterwood operations. This may also 

be true in older plantations, where shade-tolerant trees 

may become established. Two relatively even canopy 

levels can be recognized in the stand. Understory or 

overtopped trees are common. Neither canopy level is 

necessarily continuous or closed, but both canopy levels 

tend to be uniformly distributed across the stand. The 

average age of each level differs significantly from the 

other. 

3 Uneven-aged Theoretically, these stands contain trees of every age on a 

continuum from seedlings to mature canopy trees. In 

practice, uneven-aged stands are characterized by a 

broken or uneven canopy layer. Usually the largest 

number of trees is in the smaller diameter classes. As 

trees increase in diameter, their numbers diminish 

throughout the stand. Many times, instead of producing a 

negative exponential distribution of diminishing larger 

diameters, uneven-aged stands behave irregularly with 

waves of reproduction and mortality. Consider any stand 

with three or more structural layers as uneven-aged. 

Logging disturbances (examples are selection, diameter 

limit, and salvage cutting) will give a stand an unevenaged structure. 

4 Mosaic At least two distinct size classes are represented and 

these are not uniformly distributed but are grouped in 

small repeating aggregations, or occur as stringers 

<120 feet wide, throughout the stand. Each size class 

aggregation is too small to be recognized and mapped as 

an individual stand. The aggregations may or may not be 

even-aged. 

 

 86. STUMP_CD_PNWRS 

 Stump code, Pacific Northwest Research Station. A yes/no attribute 

indicating whether or not stumps are present on a condition. Only collected 

by certain FIA work units (SURVEY.RSCD = 26). 

Code Description 

Y Yes, evidence of cutting or management exists; stumps are present 

N No, evidence of cutting was not observed; stumps are not present 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 69

 87. FIRE_SRS Fire, Southern Research Station. The presence or absence of fire on the 

condition since the last survey or within the last 5 years on new/replacement 

plots. Evidence of fire must occur within the subplot. Only collected by 

certain FIA work units (SURVEY.RSCD = 33). 

Code Description 

0 No evidence of fire since last survey 

1 Evidence of burning (either prescribed or wildfire) 

 88. GRAZING_SRS 

 Grazing, Southern Research Station. The presence or absence of domestic 

animal grazing on the condition since the last survey or within the last 5 

years on new/replacement plots. Evidence of grazing must occur within the 

subplot. Only collected by certain FIA work units (SURVEY.RSCD = 33). 

Code Description 

0 No evidence of livestock use (by domestic animals) 

1 Evidence of grazing (including dung, tracks, trails, etc.) 

 89. HARVEST_TYPE1_SRS 

 Harvest type code 1, Southern Research Station. This variable is populated 

when the corresponding variable TRTCD = 10. Only collected by certain FIA 

work units (SURVEY.RSCD = 33). 

Code Description 

11 Clearcut harvest – The removal of the majority of the merchantable trees in a 

stand; residual stand stocking is under 50 percent. 

12 Partial harvest – Removal primarily consisting of highest quality trees. 

Residual consists of lower quality trees because of high grading or selection 

harvest. (i.e., Uneven aged, group selection, high grading, species selection) 

13 Seed-tree/shelterwood harvest – Crop trees are harvested leaving seed source 

trees either in a shelterwood or seed tree. Also includes the final harvest of the 

seed trees. 

14 Commercial thinning – The removal of trees (usually poletimber sized) from 

poletimber-sized stands leaving sufficient stocking of growing-stock trees to 

feature in future stand development. Also included are thinning in sawtimbersized stands where poletimber-sized (or log-sized) trees have been removed to 

improve quality of those trees featured in a final harvest. 

15 Timber Stand Improvement (cut trees only) – The cleaning, release or other 

stand improvement involving non-commercial cutting applied to an immature 

stand that leaves sufficient stocking. 

16 Salvage cutting – The harvesting of dead or damaged trees or of trees in 

danger of being killed by insects, disease, flooding, or other factors in order to 

save their economic value. 

 90. HARVEST_TYPE2_SRS 

 Harvest type code 2, Southern Research Station. See 

HARVEST_TYPE1_SRS. 
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Chapter 3. Condition Table 

70 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 91. HARVEST_TYPE3_SRS 

 Harvest type code 3, Southern Research Station. See 

HARVEST_TYPE1_SRS. 

 92. LAND_USE_SRS 

 Land use, Southern Research Station. A classification indicating the present 

land use of the condition. Collected on all condition records where 

SURVEY.RSCD = 33 and PLOT.DESIGNCD = 1, 230, 231, 232, or 233, 

and were processed in NIMS. It may not be populated for other SRS plot 

designs or for SRS data that have not been processed in NIMS. Only 

collected by certain FIA work units (SURVEY.RSCD = 33). 

Code Description 

01 Timber land (COND.SITECLCD = 1, 2, 3, 4, 5, or 6) 

02 Other forest land (COND.SITECLCD = 7) 

10 Agricultural land – Land managed for crops, pasture, or other agricultural use 

and is not better described by one of the following detailed codes. The area 

must be at least 1.0 acre in size and 120.0 feet wide. NOTE: Codes 14, 15 and 

16 are collected only where PLOT.MANUAL ≥1. If PLOT.MANUAL <1, 

then codes 14 and 15 were coded 11. There was no single rule for coding 

maintained wildlife openings where PLOT.MANUAL <1, so code 16 may 

have been coded 10, 11 or 12. 

 11 Cropland 

 12 Pasture (improved through cultural practices) 

 13 Idle farmland 

 14 Orchard 

 15 Christmas tree plantation 

 16 Maintained wildlife openings 

20 Rangeland – Land primarily composed of grasses, forbs, or shrubs. This 

includes lands vegetated naturally or artificially to provide a plant cover 

managed like native vegetation and does not meet the definition of pasture. 

The area must be at least 1.0 acre in size and 120.0 feet wide. 

30 Developed – Land used primarily by humans for purposes other than forestry 

or agriculture and is not better described by one of the following detailed 

codes. NOTE: Code 30 is used to describe all developed land where 

PLOT.MANUAL <1. The following detailed codes only apply to 

PLOT.MANUAL ≥1. 

 31 Cultural: business, residential, and other places of intense human activity 

 32 Rights-of-way: improved roads, railway, power lines, maintained canal 

 33 Recreation: parks, skiing, golf courses 

 34 Mining 

40 Other – Land parcels greater than 1.0 acre in size and greater than 120.0 feet 

wide that do not fall into one of the uses described above or below. 

 41 Marsh 

 42 Wetland 

 43 Beach 

 45 Nonforest-Chaparral 

91 Census Water – Lakes, reservoirs, ponds, and similar bodies of water 4.5 acres 

in size and larger; and rivers, streams, canals, etc., 30 to 200 feet wide. 

92 Noncensus water – Lakes, reservoirs, ponds, and similar bodies of water 

1.0 acre to 4.5 acres in size. Rivers, streams, canals, etc., more than 200 feet 

wide. 

99 Nonsampled – Condition not sampled (see 

COND.COND_NONSAMPLE_REASN_CD for exact reason). 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 71

 93. OPERABILITY_SRS 

 Operability, Southern Research Station. The viability of operating logging 

equipment in the vicinity of the condition. The code represents the most 

limiting class code that occurs on each forest condition. Only collected by 

certain FIA work units (SURVEY.RSCD = 33). 

Code Description 

0 No problems. 

1 Seasonal access due to water conditions in wet weather. 

2 Mixed wet and dry areas typical of multi-channeled streams punctuated with dry 

islands. 

3 Broken terrain, cliffs, gullies, outcroppings, etc. that would severely limit 

equipment, access or use. 

4 Year-round water problems (includes islands). 

5 Slopes 20-40 percent. 

6 Slope greater than 40 percent. 

 94. STAND_STRUCTURE_SRS 

 Stand structure, Southern Research Station. The description of the 

predominant canopy structure for the condition. Only the vertical position of 

the dominant and codominant trees in the stand are considered. Only 

collected by certain FIA work units (SURVEY.RSCD = 33). 

Code Description 

0 Non-stocked – The condition is less than 10 percent stocked. 

1 Single-storied – Most of the dominant/codominant tree crowns form a single 

canopy (i.e., most of the trees are approximately the same height). 

2 Two-storied – The dominant/codominant tree crowns form two distinct canopy 

layers or stories. 

3 Multi-storied – More than two recognizable levels characterize the crown 

canopy. Dominant/codominant trees of many sizes (diameters and heights) for a 

multilevel canopy. 

 95. NF_COND_STATUS_CD 

 Nonforest condition status code. Intentionally left blank. Will be populated in 

version 5.0. 

 96. NF_COND_NONSAMPLE_REASN_CD 

 Nonforest condition nonsampled reason code. Intentionally left blank. Will 

be populated in version 5.0. 

 97. CANOPY_CVR_SAMPLE_METHOD_CD 

 Canopy cover sample method code. Intentionally left blank. Will be 

populated in version 5.0. 

 98. LIVE_CANOPY_CVR_PCT 

 Live canopy cover percent. Intentionally left blank. Will be populated in 

version 5.0. 
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72 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 99. LIVE_MISSING_CANOPY_CVR_PCT 

 Live plus missing canopy cover percent. Intentionally left blank. Will be 

populated in version 5.0. 

100. NBR_LIVE_STEMS 

 Number of live stems. Intentionally left blank. Will be populated in version 

5.0. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 73

Subplot Table (Oracle table name is SUBPLOT) 

 Column name Descriptive name Oracle data type 

1 CN Sequence number VARCHAR2(34) 

2 PLT_CN Plot sequence number VARCHAR2(34) 

3 PREV_SBP_CN Previous subplot sequence number VARCHAR2(34) 

4 INVYR Inventory year NUMBER(4) 

5 STATECD State code NUMBER(4) 

6 UNITCD Survey unit code NUMBER(2) 

7 COUNTYCD County code NUMBER(3) 

8 PLOT Phase 2 plot number NUMBER(5) 

9 SUBP Subplot number NUMBER(3) 

10 SUBP_STATUS_CD Subplot/macroplot status code NUMBER(1) 

11 POINT_NONSAMPLE_REASN_CD Point nonsampled reason code NUMBER(2) 

12 MICRCOND Microplot center condition NUMBER(1) 

13 SUBPCOND Subplot center condition NUMBER(1) 

14 MACRCOND Macroplot center condition NUMBER(1) 

15 CONDLIST Subplot/macroplot condition list NUMBER(4) 

16 SLOPE Subplot slope NUMBER(3) 

17 ASPECT Subplot aspect NUMBER(3) 

18 WATERDEP Snow/water depth NUMBER(2,1) 

19 P2A_GRM_FLG Periodic to annual growth, removal, 

and mortality flag VARCHAR2(1) 

20 CREATED_BY Created by VARCHAR2(30) 

21 CREATED_DATE Created date DATE 

22 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

23 MODIFIED_BY Modified by VARCHAR2(30) 

24 MODIFIED_DATE Modified date DATE 

25 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

26 CYCLE Inventory cycle number NUMBER(2) 

27 SUBCYCLE Inventory subcycle number NUMBER(2) 

28 ROOT_DIS_SEV_CD_PNWRS Root disease severity rating code, 

Pacific Northwest Research Station NUMBER(1) 

29 NF_SUBP_STATUS_CD Nonforest subplot status code NUMBER(1) 

30 NF_SUBP_NONSAMPLE_REASN_ 

CD 

Nonforest subplot nonsampled reason 

code NUMBER(2) 

31 P2VEG_SUBP_STATUS_CD P2 vegetation subplot status code NUMBER(1) 

32 P2VEG_SUBP_NONSAMPLE_REASN_ 

CD 

P2 vegetation subplot nonsampled 

reason code NUMBER(2) 

33 INVASIVE_SUBP_STATUS_CD Invasive subplot status code NUMBER(1) 

34 INVASIVE_NONSAMPLE_REASN_CD Invasive nonsampled reason code NUMBER(2) 
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74 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (CN) N/A SBP_PK 

Unique (PLT_CN, SUBP) N/A SBP_UK 

Natural (STATECD, INVYR, 

UNITCD, COUNTYCD, 

PLOT, SUBP) 

N/A SBP_NAT_I 

Foreign (PLT_CN, MICRCOND) SUBPLOT to COND SBP_CND_FK2 

(PLT_CN, MACRCOND) SUBPLOT to COND SBP_CND_FK3 

(PLT_CN, SUBPCOND) SUBPLOT to COND SBP_CND_FK 

(PLT_CN) SUBPLOT to PLOT SBP_PLT_FK 

Note: The SUBPLOT record may not exist for some periodic inventory data. 

 1. CN Sequence number. A unique sequence number used to identify a subplot 

record. 

 2. PLT_CN Plot sequence number. Foreign key linking the subplot record to the plot 

record. 

 3. PREV_SBP_CN 

 Previous subplot sequence number. Foreign key linking the subplot record to 

the previous inventory’s subplot record for this subplot. Only populated on 

annual remeasured plots. 

 4. INVYR Inventory year. The year that best represents when the inventory data were 

collected. Under the annual inventory system, a group of plots is selected 

each year for sampling. The selection is based on a panel system. INVYR is 

the year in which the majority of plots in that group were collected (plots in 

the group have the same panel and, if applicable, subpanel). Under periodic 

inventory, a reporting inventory year was selected, usually based on the year 

in which the majority of the plots were collected or the mid-point of the years 

over which the inventory spanned. For either annual or periodic inventory, 

INVYR is not necessarily the same as MEASYEAR. 

 Exceptions: 

 INVYR = 9999. INVYR is set to 9999 to distinguish Phase 3 plots taken by 

the western FIA work units that are “off subpanel.” This is due to differences 

in measurement intervals between Phase 3 (measurement interval = 5 years) 

and Phase 2 (measurement interval = 10 years) plots. Only users interested in 

performing certain Phase 3 data analyses should access plots with this 

anomalous value in INVYR. 

 INVYR <100. INVYR <100 indicates that population estimates were derived 

from a pre-NIMS regional processing system and the same plot either has 

been or may soon be re-processed in NIMS as part of a separate evaluation. 

The NIMS processed copy of the plot follows the standard INVYR format. 

This only applies to plots collected in the South (SURVEY.RSCD = 33) with 

the national design or a similar regional design (PLOT.DESIGNCD = 1 or 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 75

220-233) that were collected when the inventory year was 1998 through 

2005. 

 INVYR = 98 is equivalent to 1998 but processed through regional system 

 INVYR = 99 is equivalent to 1999 but processed through regional system 

 INVYR = 0 is equivalent to 2000 but processed through regional system 

 INVYR = 1 is equivalent to 2001 but processed through regional system 

 INVYR = 2 is equivalent to 2002 but processed through regional system 

 INVYR = 3 is equivalent to 2003 but processed through regional system 

 INVYR = 4 is equivalent to 2004 but processed through regional system 

 INVYR = 5 is equivalent to 2005 but processed through regional system 

 5. STATECD State code. Bureau of the Census Federal Information Processing Standards 

(FIPS) two-digit code for each State. Refer to appendix C. 

 6. UNITCD Survey unit code. Forest Inventory and Analysis survey unit identification 

number. Survey units are usually groups of counties within each State. For 

periodic inventories, Survey units may be made up of lands of particular 

owners. Refer to appendix C for codes. 

 7. COUNTYCD County code. The identification number for a county, parish, watershed, 

borough, or similar governmental unit in a State. FIPS codes from the Bureau 

of the Census are used. Refer to appendix C for codes. 

 8. PLOT Phase 2 plot number. An identifier for a plot. Along with STATECD, 

INVYR, UNITCD, COUNTYCD and/or some other combinations of 

variables, PLOT may be used to uniquely identify a plot. 

 9. SUBP Subplot number. The number assigned to the subplot. The national plot 

design (PLOT.DESIGNCD = 1) has subplot number values of 1 through 4. 

Other plot designs have various subplot number values. See 

PLOT.DESIGNCD and appendix B for information about plot designs. For 

more explanation about SUBP, contact the appropriate FIA work unit 

(table 6). 

 10. SUBP_STATUS_CD 

 Subplot/macroplot status code. A code indicating whether forest land was 

sampled on the subplot/macroplot or not. May be blank (null) in periodic 

inventories. 

Code Description 

1 Sampled – at least one accessible forest land condition present on subplot. 

2 Sampled – no accessible forest land condition present on subplot. 

3 Nonsampled. 

 11. POINT_NONSAMPLE_REASN_CD 

Point nonsampled reason code. For entire subplots (or macroplots) that 

cannot be sampled, one of the following reasons is recorded. 
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76 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Code Description 

01 Outside U.S. boundary – Entire subplot (or macroplot) is outside of the U.S. 

border. 

02 Denied access area – Access to the entire subplot (or macroplot) is denied by 

the legal owner, or by the owner of the only reasonable route to the subplot (or 

macroplot). 

03 Hazardous situation – Entire subplot (or macroplot) cannot be accessed 

because of a hazard or danger, for example cliffs, quarries, strip mines, illegal 

substance plantations, high water, etc. 

04 Time limitation – Entire subplot (or macroplot) cannot be sampled due to a 

time restriction. This code is reserved for areas with limited access, and in 

situations where it is imperative for the crew to leave before the plot can be 

completed (e.g., scheduled helicopter rendezvous). 

05 Lost data – The plot data file was discovered to be corrupt after a panel was 

completed and submitted for processing. This code is assigned to entire plots 

or full subplots that could not be processed. 

06 Lost plot – Entire plot cannot be found. Used for the four subplots that are 

required for this plot. 

07 Wrong location – Previous plot can be found, but its placement is beyond the 

tolerance limits for plot location. Used for the four subplots that are required 

for this plot. 

08 Skipped visit – Entire plot skipped. Used for plots that are not completed prior 

to the time a panel is finished and submitted for processing. Used for the four 

subplots that are required for this plot. This code is for office use only. 

09 Dropped intensified plot - Intensified plot dropped due to a change in grid 

density. Used for the four subplots that are required for this plot. This code 

used only by units engaged in intensification. This code is for office use only. 

10 Other – Entire subplot (or macroplot) not sampled due to a reason other than 

one of the specific reasons already listed. 

11 Ocean – Subplot/macroplot falls in ocean water below mean high tide line. 

 12. MICRCOND Microplot center condition. Condition number for the condition at the center 

of the microplot. 

 13. SUBPCOND Subplot center condition. Condition number for the condition at the center of 

the subplot. 

 14. MACRCOND Macroplot center condition. Condition number for the condition at the center 

of the macroplot. Blank (null) if macroplot is not measured. 

 15. CONDLIST Subplot/macroplot condition list. (Core optional.) This is a listing of all 

condition classes located within the 24.0/58.9-foot radius around the 

subplot/macroplot center. A maximum of four conditions is permitted on any 

individual subplot/macroplot. For example: 2300 means these conditions 

(conditions 2 and 3) are on the subplot/macroplot. 

 16. SLOPE Subplot slope. The angle of slope, in percent, of the subplot, determined by 

sighting along the average incline or decline of the subplot. If the slope 

changes gradually, an average slope is recorded. If the slope changes across 

the subplot but is predominantly of one direction, the predominant slope is 

recorded. Valid values are 0 through 155. 

 17. ASPECT Subplot aspect. The direction of slope, to the nearest degree, of the subplot, 

determined along the direction of slope. If the aspect changes gradually, an 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 77

average aspect is recorded. If the aspect changes across the subplot but is 

predominantly of one direction, the predominant aspect is recorded. North is 

recorded as 360. When slope is <5 percent, there is no aspect and it is 

recorded as 000. 

 18. WATERDEP Snow/water depth. The approximate depth in feet of water or snow covering 

the subplot. Populated for all forested subplots using the National Field 

Guide protocols (PLOT.MANUAL ≥1.0) and populated by some FIA work 

units where PLOT.MANUAL <1.0. 

 19. P2A_GRM_FLG 

 Periodic to annual growth, removal, and mortality flag. A code indicating if 

this subplot is part of a periodic inventory (usually from a variable-radius 

plot design) that is only included for the purposes of computing growth, 

removals and/or mortality estimates. Tree data associated with this subplot 

does not contribute to current estimates of such attributes as volume, biomass 

or number of trees. The flag is set to Y for those subplots that are needed for 

estimation and otherwise is left blank (null). 

 20. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 21. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 22. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 23. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 24. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 
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78 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 25. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 

 26. CYCLE Inventory cycle number. A number assigned to a set of plots, measured over 

a particular period of time from which a State estimate using all possible 

plots is obtained. A cycle number >1 does not necessarily mean that 

information for previous cycles resides in the database. A cycle is relevant 

for periodic and annual inventories. 

 27. SUBCYCLE Inventory subcycle number. For an annual inventory that takes n years to 

measure all plots, subcycle shows in which of the n years of the cycle the 

data were measured. Subcycle is 0 for a periodic inventory. Subcycle 99 may 

be used for plots that are not included in the estimation process. 

 28. ROOT_DIS_SEV_CD_PNWRS 

 Root disease severity rating code, Pacific Northwest Research Station. The 

root disease severity rating that describes the degree of root disease present. 

Only collected by certain FIA work units (SURVEY.RSCD = 26). 

Code Description 

0 No evidence of root disease visible within 50 feet of the 58.9 foot 

macroplot. 

1 Root disease present within 50 feet of the macroplot, but no evidence of 

disease on the macroplot. 

2 Minor evidence of root disease on the macroplot, such as suppressed tree 

killed by root disease, or a minor part of the overstory showing symptoms of 

infection. Little or no detectable reduction in canopy closure or volume. 

3 Canopy reduction evident, up to 20 percent; usually as a result of death of 1 

codominant tree on an otherwise fully stocked site. In absence of mortality, 

numerous trees showing symptoms of root disease infection. 

4 Canopy reduction at least 20 percent; up to 30 percent as a result of root 

disease mortality. Snags and downed trees removed from canopy by disease 

as well as live trees with advance symptoms of disease contribute to impact. 

5 Canopy reduction 30-50 percent as a result of root disease. At least half of 

the ground area of macroplot considered infested with evidence of root 

disease-killed trees. Macroplots representing mature stands with half of their 

volume in root disease-tolerant species usually do not go much above 

severity 5 because of the ameliorating effect of the disease-tolerant trees. 

6 50-75 percent reduction in canopy with most of the ground area considered 

infested as evidenced by symptomatic trees. Much of the canopy variation in 

this category is generally a result of root disease-tolerant species occupying 

infested ground. 

7 At least 75 percent canopy reduction. Macroplots that reach this severity 

level usually are occupied by only the most susceptible species. There are 

very few of the original overstory trees remaining although infested ground 

is often densely stocked with regeneration of susceptible species. 

8 The entire macroplot falls within a definite root disease pocket with only 

one or very few susceptible overstory trees present. 

9 The entire macroplot falls within a definite root disease pocket with no 

overstory trees of the susceptible species present. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 79

 29. NF_SUBP_STATUS_CD 

 Nonforest subplot status code. Intentionally left blank. Will be populated in 

version 5.0. 

 30. NF_SUBP_NONSAMPLE_REASN_CD 

 Nonforest subplot nonsampled reason code. Intentionally left blank. Will be 

populated in version 5.0. 

 31. P2VEG_SUBP_STATUS_CD 

 P2 vegetation subplot status code. Intentionally left blank. Will be populated 

in version 5.0. 

 32. P2VEG_SUBP_NONSAMPLE_REASN_CD 

 P2 vegetation subplot nonsampled reason code. Intentionally left blank. Will 

be populated in version 5.0. 

 33. INVASIVE_SUBP_STATUS_CD 

 Invasive subplot status code. Intentionally left blank. Will be populated in 

version 5.0. 

 34. INVASIVE_NONSAMPLE_REASN_CD 

 Invasive nonsampled reason code. Intentionally left blank. Will be populated 

in version 5.0. 
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80 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Subplot Condition Table (Oracle table name is SUBP_COND) 

 Column name Descriptive name Oracle data type 

1 CN Sequence number VARCHAR2(34) 

2 PLT_CN Plot sequence number VARCHAR2(34) 

3 INVYR Inventory year NUMBER(4) 

4 STATECD State code NUMBER(4) 

5 UNITCD Survey unit code NUMBER(2) 

6 COUNTYCD County code NUMBER(3) 

7 PLOT Phase 2 plot number NUMBER(5) 

8 SUBP Subplot number NUMBER(3) 

9 CONDID Condition class number NUMBER(1) 

10 CREATED_BY Created by VARCHAR2(30) 

11 CREATED_DATE Created date DATE 

12 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

13 MODIFIED_BY Modified by VARCHAR2(30) 

14 MODIFIED_DATE Modified date DATE 

15 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

16 MICRCOND_PROP Microplot-condition proportion NUMBER(5,4) 

17 SUBPCOND_PROP Subplot-condition proportion NUMBER(5,4) 

18 MACRCOND_PROP Macroplot-condition proportion NUMBER(5,4) 

19 NONFR_INCL_PCT_SUBP Nonforest inclusions percentage of subplot NUMBER(3) 

20 NONFR_INCL_PCT_MACRO Nonforest inclusions percentage of macroplot NUMBER(3) 

21 CYCLE Inventory cycle number NUMBER(2) 

22 SUBCYCLE Inventory subcycle number NUMBER(2) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (CN) N/A SCD_PK 

Unique (PLT_CN, SUBP, CONDID) N/A SCD_UK 

Natural (STATECD, INVYR, 

UNITCD, COUNTYCD, 

PLOT, SUBP, CONDID) 

N/A SCD_NAT_I 

Foreign (PLT_CN, CONDID) SUBP_COND to COND SCD_CND_FK 

(PLT_CN) SUBP_COND to PLOT SCD_PLT_FK 

(PLT_CN, SUBP) SUBP_COND to SUBPLOT SCD_SBP_FK 

Note: The SUBP_COND record may not exist for some periodic inventory data. 

 1. CN Sequence number. A unique sequence number used to identify a subplot 

condition record. 

 2. PLT_CN Plot sequence number. Foreign key linking the subplot condition record to 

the plot record. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 81

 3. INVYR Inventory year. The year that best represents when the inventory data were 

collected. Under the annual inventory system, a group of plots is selected 

each year for sampling. The selection is based on a panel system. INVYR is 

the year in which the majority of plots in that group were collected (plots in 

the group have the same panel and, if applicable, subpanel). Under periodic 

inventory, a reporting inventory year was selected, usually based on the year 

in which the majority of the plots were collected or the mid-point of the years 

over which the inventory spanned. For either annual or periodic inventory, 

INVYR is not necessarily the same as MEASYEAR. 

 Exceptions: 

 INVYR = 9999. INVYR is set to 9999 to distinguish Phase 3 plots taken by 

the western FIA work units that are “off subpanel.” This is due to differences 

in measurement intervals between Phase 3 (measurement interval = 5 years) 

and Phase 2 (measurement interval = 10 years) plots. Only users interested in 

performing certain Phase 3 data analyses should access plots with this 

anomalous value in INVYR. 

 INVYR <100. INVYR <100 indicates that population estimates were derived 

from a pre-NIMS regional processing system and the same plot either has 

been or may soon be re-processed in NIMS as part of a separate evaluation. 

The NIMS processed copy of the plot follows the standard INVYR format. 

This only applies to plots collected in the South (SURVEY.RSCD = 33) with 

the national design or a similar regional design (PLOT.DESIGNCD = 1 or 

220-233) that were collected when the inventory year was 1998 through 

2005. 

 INVYR = 98 is equivalent to 1998 but processed through regional system 

 INVYR = 99 is equivalent to 1999 but processed through regional system 

 INVYR = 0 is equivalent to 2000 but processed through regional system 

 INVYR = 1 is equivalent to 2001 but processed through regional system 

 INVYR = 2 is equivalent to 2002 but processed through regional system 

 INVYR = 3 is equivalent to 2003 but processed through regional system 

 INVYR = 4 is equivalent to 2004 but processed through regional system 

 INVYR = 5 is equivalent to 2005 but processed through regional system 

 4. STATECD State code. Bureau of the Census Federal Information Processing Standards 

(FIPS) two-digit code for each State. Refer to appendix C. 

 5. UNITCD Survey unit code. Forest Inventory and Analysis survey unit identification 

number. Survey units are usually groups of counties within each State. For 

periodic inventories, Survey units may be made up of lands of particular 

owners. Refer to appendix C for codes. 

 6. COUNTYCD County code. The identification number for a county, parish, watershed, 

borough, or similar governmental unit in a State. FIPS codes from the Bureau 

of the Census are used. Refer to appendix C for codes. 
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82 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 7. PLOT Phase 2 plot number. An identifier for a plot. Along with STATECD, 

INVYR, UNITCD, COUNTYCD and/or some other combination of 

variables, PLOT may be used to uniquely identify a plot. 

 8. SUBP Subplot number. The number assigned to the subplot. The national plot 

design (PLOT.DESIGNCD = 1) has subplot number values of 1 through 4. 

Other plot designs have various subplot number values. See 

PLOT.DESIGNCD and appendix B for information about plot designs. For 

more explanation about SUBP, contact the appropriate FIA work unit. 

 9. CONDID Condition class number. Unique identifying number assigned to each 

condition on a plot. A condition is initially defined by condition class status. 

Differences in reserved status, owner group, forest type, stand-size class, 

regeneration status, and stand density further define condition for forest land. 

Mapped nonforest conditions are also assigned numbers. At the time of the 

plot establishment, the condition class at plot center (the center of subplot 1) 

is usually designated as condition class 1. Other condition classes are 

assigned numbers sequentially at the time each condition class is delineated. 

On a plot, each sampled condition class must have a unique number that can 

change at remeasurement to reflect new conditions on the plot. 

 10. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 11. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 12. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 13. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 14. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 
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 15. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 

 16. MICRCOND_PROP 

 Microplot-condition proportion. Proportion of this microplot in this 

condition. 

 17. SUBPCOND_PROP 

 Subplot-condition proportion. Proportion of this subplot in this condition. 

 18. MACRCOND_PROP 

 Macroplot-condition proportion. Proportion of this macroplot in this 

condition. 

 19. NONFR_INCL_PCT_SUBP 

 Nonforest inclusion percentage of subplot. Nonforest area estimate, 

expressed as a percentage, of the 24.0-foot, fixed-radius subplot present 

within a mapped, accessible forestland condition class in Oregon, 

Washington, and California. Only collected by certain FIA work units 

(SURVEY.RSCD = 26). 

 20. NONFR_INCL_PCT_MACRO 

 Nonforest inclusion percentage of macroplot. Nonforest area estimate, 

expressed as a percentage, of the 58.9-foot, fixed-radius macroplot present 

within a mapped, accessible forestland condition class in Oregon, 

Washington, and California. Only collected by certain FIA work units 

(SURVEY.RSCD = 26). 

 21. CYCLE Inventory cycle number. A number assigned to a set of plots, measured over 

a particular period of time from which a State estimate using all possible 

plots is obtained. A cycle number >1 does not necessarily mean that 

information for previous cycles resides in the database. A cycle is relevant 

for periodic and annual inventories. 

 22. SUBCYCLE Inventory subcycle number. For an annual inventory that takes n years to 

measure all plots, subcycle shows in which of the n years of the cycle the 

data were measured. Subcycle is 0 for a periodic inventory. Subcycle 99 may 

be used for plots that are not included in the estimation process. 
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84 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Tree Table (Oracle table name is TREE) 

 Column name Descriptive name Oracle data type 

1 CN Sequence number VARCHAR2(34) 

2 PLT_CN Plot sequence number VARCHAR2(34) 

3 PREV_TRE_CN Previous tree sequence number VARCHAR2(34) 

4 INVYR Inventory year NUMBER(4) 

5 STATECD State code NUMBER(4) 

6 UNITCD Survey unit code NUMBER(2) 

7 COUNTYCD County code NUMBER(3) 

8 PLOT Phase 2 plot number NUMBER(5) 

9 SUBP Subplot number NUMBER(3) 

10 TREE Tree record number NUMBER(9) 

11 CONDID Condition class number NUMBER(1) 

12 AZIMUTH Azimuth NUMBER(3) 

13 DIST Horizontal distance NUMBER(4,1) 

14 PREVCOND Previous condition number NUMBER(1) 

15 STATUSCD Status code NUMBER(1) 

16 SPCD Species code NUMBER 

17 SPGRPCD Species group code NUMBER(2) 

18 DIA Current diameter NUMBER(5,2) 

19 DIAHTCD Diameter height code NUMBER(1) 

20 HT Total height NUMBER(3) 

21 HTCD Height method code NUMBER(2) 

22 ACTUALHT Actual height NUMBER(3) 

23 TREECLCD Tree class code NUMBER(2) 

24 CR Compacted crown ratio NUMBER(3) 

25 CCLCD Crown class code NUMBER(2) 

26 TREEGRCD Tree grade code NUMBER(2) 

27 AGENTCD Cause of death (agent) code NUMBER(2) 

28 CULL Rotten and missing cull NUMBER(3) 

29 DAMLOC1 Damage location 1 NUMBER(2) 

30 DAMTYP1 Damage type 1 NUMBER(2) 

31 DAMSEV1 Damage severity 1 NUMBER(1) 

32 DAMLOC2 Damage location 2 NUMBER(2) 

33 DAMTYP2 Damage type 2 NUMBER(2) 

34 DAMSEV2 Damage severity 2 NUMBER(1) 

35 DECAYCD Decay class code NUMBER(2) 

36 STOCKING Tree stocking NUMBER(7,4) 
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 Column name Descriptive name Oracle data type 

37 WDLDSTEM Woodland tree species stem count NUMBER(3) 

38 VOLCFNET Net cubic-foot volume NUMBER(11,6) 

39 VOLCFGRS Gross cubic-foot volume NUMBER(11,6) 

40 VOLCSNET Net cubic-foot volume in the sawlog 

portion NUMBER(11,6) 

41 VOLCSGRS Gross cubic-foot volume in the sawlog 

portion NUMBER(11,6) 

42 VOLBFNET Net board-foot volume in the sawlog 

portion NUMBER(11,6) 

43 VOLBFGRS Gross board-foot volume in the sawlog 

portion NUMBER(11,6) 

44 VOLCFSND Sound cubic-foot volume NUMBER(11,6) 

45 GROWCFGS 

Net annual merchantable cubic-foot 

growth of a growing-stock tree on 

timberland 

NUMBER(11,6) 

46 GROWBFSL 

Net annual merchantable board-foot 

growth of a sawtimber size tree on 

timberland 

NUMBER(11,6) 

47 GROWCFAL Net annual sound cubic-foot growth of 

a live tree on timberland NUMBER(11,6) 

48 MORTCFGS 

Cubic-foot volume of a growing-stock 

tree on timberland for mortality 

purposes 

NUMBER(11,6) 

49 MORTBFSL 

Board-foot volume of a sawtimber size 

tree on timberland for mortality 

purposes 

NUMBER(11,6) 

50 MORTCFAL Sound cubic-foot volume of a tree on 

timberland for mortality purposes NUMBER(11,6) 

51 REMVCFGS 

Cubic-foot volume of a growing-stock 

tree on timberland for removal 

purposes 

NUMBER(11,6) 

52 REMVBFSL 

Board-foot volume of a sawtimber size 

tree on timberland for removal 

purposes 

NUMBER(11,6) 

53 REMVCFAL Sound cubic-foot volume of a tree on 

timberland for removal purposes NUMBER(11,6) 

54 DIACHECK Diameter check code NUMBER(2) 

55 MORTYR Mortality year NUMBER(4) 

56 SALVCD Salvable dead code NUMBER(2) 

57 UNCRCD Uncompacted live crown ratio NUMBER(3) 

58 CPOSCD Crown position code NUMBER(2) 

59 CLIGHTCD Crown light exposure code NUMBER(2) 

60 CVIGORCD Crown vigor code (sapling) NUMBER(2) 

61 CDENCD Crown density code NUMBER(3) 

62 CDIEBKCD Crown dieback code NUMBER(3) 

63 TRANSCD Foliage transparency code NUMBER(3) 

64 TREEHISTCD Tree history code NUMBER(3) 
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 Column name Descriptive name Oracle data type 

65 DIACALC Current diameter calculated NUMBER(5,2) 

66 BHAGE Breast height age NUMBER(4) 

67 TOTAGE Total age NUMBER(4) 

68 CULLDEAD Dead cull NUMBER(3) 

69 CULLFORM Form cull NUMBER(3) 

70 CULLMSTOP Missing top cull NUMBER(3) 

71 CULLBF Board-foot cull NUMBER(3) 

72 CULLCF Cubic-foot cull NUMBER(3) 

73 BFSND Board-foot cull soundness NUMBER(3) 

74 CFSND Cubic-foot-cull soundness NUMBER(3) 

75 SAWHT Sawlog height NUMBER(2) 

76 BOLEHT Bole height NUMBER(3) 

77 FORMCL Form class NUMBER(1) 

78 HTCALC Current height calculated NUMBER(3) 

79 HRDWD_CLUMP_CD Hardwood clump code NUMBER(1) 

80 SITREE Calculated site index NUMBER(3) 

81 CREATED_BY Created by VARCHAR2(30) 

82 CREATED_DATE Created date DATE 

83 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

84 MODIFIED_BY Modified by VARCHAR2(30) 

85 MODIFIED_DATE Modified date DATE 

86 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

87 MORTCD Mortality code NUMBER(1) 

88 HTDMP Height to diameter measurement point NUMBER(3,1) 

89 ROUGHCULL Rough cull NUMBER(2) 

90 MIST_CL_CD Mistletoe class code NUMBER(1) 

91 CULL_FLD Rotten/missing cull, field recorded NUMBER(2) 

92 RECONCILECD Reconcile code NUMBER(1) 

93 PREVDIA Previous diameter NUMBER(5,2) 

94 FGROWCFGS 

Net annual merchantable cubic-foot 

growth of a growing-stock tree on 

forest land 

NUMBER(11,6) 

95 FGROWBFSL 

Net annual merchantable board-foot 

growth of a sawtimber tree on forest 

land 

NUMBER(11,6) 

96 FGROWCFAL Net annual sound cubic-foot growth of 

a live tree on forest land NUMBER(11,6) 

97 FMORTCFGS 

Cubic-foot volume of a growing-stock 

tree for mortality purposes on forest 

land 

NUMBER(11,6) 
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 Column name Descriptive name Oracle data type 

98 FMORTBFSL Board-foot volume of a sawtimber tree 

for mortality purposes on forest land NUMBER(11,6) 

99 FMORTCFAL Sound cubic-foot volume of a tree for 

mortality purposes on forest land NUMBER(11,6) 

100 FREMVCFGS 

Cubic-foot volume of a growing-stock 

tree for removal purposes on forest 

land 

NUMBER(11,6) 

101 FREMVBFSL 

Board-foot volume of a sawtimber size 

tree for removal purposes on forest 

land 

NUMBER(11,6) 

102 FREMVCFAL Sound cubic-foot volume of the tree 

for removal purposes on forest land NUMBER(11,6) 

103 P2A_GRM_FLG Periodic to annual growth, removal, 

and mortality flag VARCHAR2(1) 

104 TREECLCD_NERS Tree class code, Northeastern 

Research Station NUMBER(2) 

105 TREECLCD_SRS Tree class code, Southern Research 

Station NUMBER(2) 

106 TREECLCD_NCRS Tree class code, North Central 

Research Station NUMBER(2) 

107 TREECLCD_RMRS Tree class code, Rocky Mountain 

Research Station NUMBER(2) 

108 STANDING_DEAD_CD Standing dead code NUMBER(2) 

109 PREV_STATUS_CD Previous tree status code NUMBER(1) 

110 PREV_WDLDSTEM Previous woodland stem count NUMBER(3) 

111 TPA_UNADJ Trees per acre unadjusted NUMBER(11,6) 

112 TPAMORT_UNADJ Mortality trees per acre unadjusted NUMBER(11,6) 

113 TPAREMV_UNADJ Removal trees per acre unadjusted NUMBER(11,6) 

114 TPAGROW_UNADJ Growth trees per acre unadjusted NUMBER(11,6) 

115 DRYBIO_BOLE Dry biomass in the merchantable bole NUMBER(13,6) 

116 DRYBIO_TOP Dry biomass in the top of the tree NUMBER(13,6) 

117 DRYBIO_STUMP Dry biomass in the tree stump NUMBER(13,6) 

118 DRYBIO_SAPLING Dry biomass of saplings NUMBER(13,6) 

119 DRYBIO_WDLD_SPP Dry biomass of woodland tree species NUMBER(13,6) 

120 DRYBIO_BG Dry biomass of the roots NUMBER(13,6) 

121 CARBON_AG Carbon in the aboveground portion of 

the tree NUMBER(13,6) 

122 CARBON_BG Carbon in the belowground portion of 

the tree NUMBER(13,6) 

123 CYCLE Inventory cycle number NUMBER(2) 

124 SUBCYCLE Inventory subcycle number NUMBER(2) 

125 BORED_CD_PNWRS Tree bored code, Pacific Northwest 

Research Station NUMBER(1) 

126 DAMLOC1_PNWRS Damage location 1, Pacific Northwest 

Research Station NUMBER(2) 

127 DAMLOC2_PNWRS Damage location 2, Pacific Northwest 

Research Station NUMBER(2) 
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 Column name Descriptive name Oracle data type 

128 DIACHECK_PNWRS Diameter check, Pacific Northwest 

Research Station NUMBER(1) 

129 DMG_AGENT1_CD_PNWRS Damage agent 1, Pacific Northwest 

Research Station NUMBER(2) 

130 DMG_AGENT2_CD_PNWRS Damage agent 2, Pacific Northwest 

Research Station NUMBER(2) 

131 DMG_AGENT3_CD_PNWRS Damage agent 3, Pacific Northwest 

Research Station NUMBER(2) 

132 MIST_CL_CD_PNWRS Leafy mistletoe class code, Pacific 

Northwest Research Station NUMBER(1) 

133 SEVERITY1_CD_PNWRS Damage severity 1, Pacific Northwest 

Research Station for years 2001-2004 NUMBER(1) 

134 SEVERITY1A_CD_PNWRS Damage severity 1A, Pacific 

Northwest Research Station NUMBER(2) 

135 SEVERITY1B_CD_PNWRS Damage severity 1B, Pacific 

Northwest Research Station NUMBER(1) 

136 SEVERITY2_CD_PNWRS Damage severity 2, Pacific Northwest 

Research Station for years 2001-2004 NUMBER(1) 

137 SEVERITY2A_CD_PNWRS 

Damage severity 2A, Pacific 

Northwest Research Station starting in 

2005 

NUMBER(2) 

138 SEVERITY2B_CD_PNWRS 

Damage severity 2B, Pacific 

Northwest Research Station starting in 

2005 

NUMBER(1) 

139 SEVERITY3_CD_PNWRS Damage severity 3, Pacific Northwest 

Research Station for years 2001-2004 NUMBER(1) 

140 UNKNOWN_DAMTYP1_PNWRS Unknown damage type 1, Pacific 

Northwest Research Station NUMBER(1) 

141 UNKNOWN_DAMTYP2_PNWRS Unknown damage type 2, Pacific 

Northwest Research Station NUMBER(1) 

142 PREV_PNTN_SRS Previous periodic prism point, tree 

number, Southern Research Station NUMBER(4) 

Type of key Column(s) Tables to link Abbreviated notation 

Primary (CN) N/A TRE_PK 

Unique (PLT_CN, SUBP, TREE) N/A TRE_UK 

Natural (STATECD, INVYR, UNITCD, 

COUNTYCD, PLOT, SUBP, TREE) 

N/A TRE_NAT_I 

Foreign (PLT_CN) TREE to PLOT TRE_PLT_FK 

 1. CN Sequence number. A unique sequence number used to identify a tree record. 

 2. PLT_CN Plot sequence number. Foreign key linking the tree record to the plot record. 

 3. PREV_TRE_CN 

 Previous tree sequence number. Foreign key linking the tree to the previous 

inventory’s tree record for this tree. Only populated on trees remeasured from 

a previous annual inventory. 

 4. INVYR Inventory year. The year that best represents when the inventory data were 

collected. Under the annual inventory system, a group of plots is selected 
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each year for sampling. The selection is based on a panel system. INVYR is 

the year in which the majority of plots in that group were collected (plots in 

the group have the same panel and, if applicable, subpanel). Under periodic 

inventory, a reporting inventory year was selected, usually based on the year 

in which the majority of the plots were collected or the mid-point of the years 

over which the inventory spanned. For either annual or periodic inventory, 

INVYR is not necessarily the same as MEASYEAR. 

 Exceptions: 

 INVYR = 9999. INVYR is set to 9999 to distinguish Phase 3 plots taken by 

the western FIA work units that are “off subpanel.” This is due to differences 

in measurement intervals between Phase 3 (measurement interval = 5 years) 

and Phase 2 (measurement interval = 10 years) plots. Only users interested in 

performing certain Phase 3 data analyses should access plots with this 

anomalous value in INVYR. 

 INVYR <100. INVYR <100 indicates that population estimates were derived 

from a pre-NIMS regional processing system and the same plot either has 

been or may soon be re-processed in NIMS as part of a separate evaluation. 

The NIMS processed copy of the plot follows the standard INVYR format. 

This only applies to plots collected in the South (SURVEY.RSCD = 33) with 

the national design or a similar regional design (PLOT.DESIGNCD = 1 or 

220-233) that were collected when the inventory year was 1998 through 

2005. 

 INVYR = 98 is equivalent to 1998 but processed through regional system 

 INVYR = 99 is equivalent to 1999 but processed through regional system 

 INVYR = 0 is equivalent to 2000 but processed through regional system 

 INVYR = 1 is equivalent to 2001 but processed through regional system 

 INVYR = 2 is equivalent to 2002 but processed through regional system 

 INVYR = 3 is equivalent to 2003 but processed through regional system 

 INVYR = 4 is equivalent to 2004 but processed through regional system 

 INVYR = 5 is equivalent to 2005 but processed through regional system 

 5. STATECD State code. Bureau of the Census Federal Information Processing Standards 

(FIPS) two-digit code for each State. Refer to appendix C. 

 6. UNITCD Survey unit code. Forest Inventory and Analysis survey unit identification 

number. Survey units are usually groups of counties within each State. For 

periodic inventories, Survey units may be made up of lands of particular 

owners. Refer to appendix C for codes. 

 7. COUNTYCD County code. The identification number for a county, parish, watershed, 

borough, or similar governmental unit in a State. FIPS codes from the Bureau 

of the Census are used. Refer to appendix C for codes. 

 8. PLOT Phase 2 plot number. An identifier for a plot. Along with STATECD, 

INVYR, UNITCD, COUNTYCD and/or some other combinations of 

variables, PLOT may be used to uniquely identify a plot. 
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90 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 9. SUBP Subplot number. The number assigned to the subplot. The national plot 

design (PLOT.DESIGNCD = 1) has subplot number values of 1 through 4. 

Other plot designs have various subplot number values. See 

PLOT.DESIGNCD and appendix B for information about plot designs. For 

more explanation about SUBP, contact the appropriate FIA work unit. 

 10. TREE Tree record number. A number used to uniquely identify a tree on a subplot. 

Tree numbers can be used to track trees when PLOT.DESIGNCD is the same 

between inventories. 

 11. CONDID Condition class number. Unique identifying number assigned to each 

condition on a plot. A condition is initially defined by condition class status. 

Differences in reserved status, owner group, forest type, stand-size class, 

regeneration status, and stand density further define condition for forest land. 

Mapped nonforest conditions are also assigned numbers. At the time of the 

plot establishment, the condition class at plot center (the center of subplot 1) 

is usually designated as condition class 1. Other condition classes are 

assigned numbers sequentially at the time each condition class is delineated. 

On a plot, each sampled condition class must have a unique number that can 

change at remeasurement to reflect new conditions on the plot. 

 12. AZIMUTH Azimuth. The direction, to the nearest degree, from subplot center (microplot 

center for saplings) to the center of the base of the tree (geographic center for 

multi-stemmed woodland species). Due north is represented by 360 degrees. 

This attribute is populated for live and standing dead trees in a forest 

condition that were measured on any of the four subplots of the national plot 

design. It may be populated for other tree records. 

 13. DIST Horizontal distance. The horizontal distance in feet from subplot center 

(microplot center for saplings) to the center of the base of the tree 

(geographic center for multi-stemmed woodland species). This attribute is 

populated for live and standing dead trees in a forest condition that were 

measured on any of the four subplots of the national plot design. It may be 

populated for other tree records. 

 14. PREVCOND Previous condition number. Identifies the condition within the plot on which 

the tree occurred at the previous inventory. 

 15. STATUSCD Status code. A code indicating whether the sample tree is live, cut, or dead at 

the time of measurement. Includes dead and cut trees, which are required to 

estimate aboveground biomass and net annual volume for growth, mortality, 

and removals. This code is not used when querying data for change estimates. 

Note: New and replacement plots use only codes 1 and 2. 
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Code Description 

0 No status – Tree is not presently in the sample (remeasurement plots only). Tree 

was incorrectly tallied at the previous inventory, currently not tallied due to 

definition or procedural change, or is not tallied due to natural causes. 

RECONCILECD = 5-9 required for remeasured annual inventory data but not 

for periodic inventory data. 

1 Live tree 

2 Dead tree 

3 Removed – Cut and removed by direct human activity related to harvesting, 

silviculture or land clearing. This tree is assumed to be utilized. 

 

 16. SPCD Species code. An FIA tree species code. Refer to appendix F for codes. 

 17. SPGRPCD Species group code. A code assigned to each tree species in order to group 

them for reporting purposes on presentation tables. Codes and their 

associated names (see REF_SPECIES_GROUP.NAME) are shown in 

appendix G. Individual tree species and corresponding species group codes 

are shown in appendix F. 

 18. DIA Current diameter. The current diameter (in inches) of the sample tree at the 

point of diameter measurement. For additional information about where the 

tree diameter is measured, see DIAHTCD or HTDMP. DIA for live trees 

contains the measured value. DIA for cut and dead trees presents problems 

associated with uncertainty of when the tree was cut or died as well as 

structural deterioration of dead trees. Consult individual FIA work units for 

explanations of how DIA is collected for dead and cut trees. 

 19. DIAHTCD Diameter height code. A code indicating the location at which diameter was 

measured. For trees with code 1 (DBH), the actual measurement point may 

be found in HTDMP. 

Code Description 

1 Breast height (DBH) 

2 Root collar (DRC) 

 20. HT Total height. (Core Phase 2: ≥5.0-inch DBH/DRC live trees; Core optional 

Phase 2: 1.0-4.9-inch DBH/DRC live trees and ≥5.0-inch DBH/DRC 

standing dead trees. Core Phase 3: ≥1.0-inch DBH/DRC live trees; Core 

optional Phase 3: ≥5.0 inch DBH/DRC standing dead trees.) The total 

length (height) of a sample tree (in feet) from the ground to the tip of the 

apical meristem. The total length of a tree is not always its actual length. If 

the main stem is broken, the actual length is measured or estimated and the 

missing piece is added to the actual length to estimate total length. The 

amount added is determined by measuring the broken piece if it can be 

located on the ground; otherwise it is estimated. The minimum height for 

timber species is 5 feet and for woodland species is 1 foot. 

 21. HTCD Height method code. (Core Phase 2: ≥5.0-inch DBH/DRC live trees; Core 

optional Phase 2: 1.0-4.9-inch DBH/DRC live trees and ≥5.0-inch DBH/DRC 

standing dead trees. Core Phase 3: ≥1.0-inch DBH/DRC live trees; Core 
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92 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

optional Phase 3: ≥5.0-inch DBH/DRC standing dead trees.) A code 

indicating how length (height) was determined. 

Code Description 

1 Field measured (total and actual length) 

2 Total length visually estimated in the field, actual length measured 

3 Total and actual lengths are visually estimated 

4 Estimated with a model 

 

 22. ACTUALHT Actual height. (Core Phase 2: live and standing dead trees with broken or 

missing tops, ≥5.0-inch DBH/DRC; Core optional Phase 2: live trees 

1.0-4.9-inch DBH/DRC with broken or missing tops; Core Phase 3: 

live trees ≥1.0-inch DBH/DRC (with broken or missing tops and standing 

dead trees ≥5.0-inch DBH/DRC [with broken or missing tops]) The length 

(height) of the tree to the nearest foot from ground level to the highest 

remaining portion of the tree still present and attached to the bole. If 

ACTUALHT = HT, then the tree does not have a broken top. If 

ACTUALHT <HT, then the tree does have a broken or missing top. The 

minimum height for timber species is 5 feet and for woodland species is 1 

foot. 

 23. TREECLCD Tree class code. A code indicating the general quality of the tree. In annual 

inventory, this is the tree class for both live and dead trees at the time of 

current measurement. In periodic inventory, for cut and dead trees, this is the 

tree class of the tree at the time it died or was cut. Therefore, cut and dead 

trees collected in periodic inventory can be coded as growing-stock. 

Code Description 

2 Growing-stock – All live trees of commercial species that meet minimum 

merchantability standards. In general, these trees have at least one solid 8-foot 

section, are reasonably free of form defect on the merchantable bole, and at least 

34 percent or more of the volume is merchantable. For the California, Oregon, 

and Washington inventories, a 26 percent or more merchantable volume standard 

is applied, rather than 34 percent or more. Excludes rough or rotten cull trees. 

3 Rough cull – All live trees that do not now, or prospectively, have at least one 

solid 8-foot section, reasonably free of form defect on the merchantable bole, or 

have 67 percent or more of the merchantable volume cull; and more than half of 

this cull is due to sound dead wood cubic-foot loss or severe form defect volume 

loss. For the California, Oregon, and Washington inventories, 75 percent or more 

cull, rather than 67 percent or more cull, applies. This class also contains all trees 

of noncommercial species, or those species where SPGRPCD equals 23 (western 

woodland softwoods), 43 (eastern noncommercial hardwoods), or 48 (western 

woodland hardwoods). Refer to appendix F to find the species that have these 

SPGRPCD codes. For dead trees, this code indicates that the tree is salvable 

(sound). 

4 Rotten cull – All live trees with 67 percent or more of the merchantable volume 

cull, and more than half of this cull is due to rotten or missing cubic-foot volume 

loss. California, Oregon, and Washington inventories use a 75 percent cutoff. 

For dead trees, this code indicates that the tree is nonsalvable (not sound). 

 24. CR Compacted crown ratio. The percent of the tree bole supporting live, healthy 

foliage (the crown is ocularly compacted to fill in gaps) when compared to 

actual length (ACTUALHT). When PLOT.MANUAL <1.0 the variable may 
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have been a code, which was converted to the midpoint of the ranges 

represented by the codes, and is stored as a percentage. 

 25. CCLCD Crown class code. A code indicating the amount of sunlight received and the 

crown position within the canopy. 

Code Description 

1 Open grown – Trees with crowns that have received full light from above and 

from all sides throughout all or most of their life, particularly during early 

development. 

2 Dominant – Trees with crowns extending above the general level of the canopy 

and receiving full light from above and partly from the sides; larger than the 

average trees in the stand, and with crowns well developed, but possibly 

somewhat crowded on the sides. 

3 Codominant – Trees with crowns forming part of the general level of the crown 

cover and receiving full light from above, but comparatively little from the side. 

Usually with medium crowns more or less crowded on the sides. 

4 Intermediate – Trees shorter than those in the preceding two classes, with crowns 

either below or extending into the canopy formed by the dominant and 

codominant trees, receiving little direct light from above, and none from the 

sides; usually with small crowns very crowded on the sides. 

5 Overtopped – Trees with crowns entirely below the general canopy level and 

receiving no direct light either from above or the sides. 

 

 26. TREEGRCD Tree grade code. A code indicating the quality of sawtimber-sized trees. This 

attribute is populated for live, growing-stock, sawtimber size trees on 

subplots 1-4 on national manual plots that are in a forest condition class. This 

attribute may be populated for other tree records that do not meet the above 

criteria. For example, it may be populated with the previous tree grade on 

dead and cut trees. Standards for tree grading are specific to species and 

differ slightly by research station. Only collected by certain FIA work units 

(SURVEY.RSCD = 23, 24, or 33). Tree grade codes range from 1 to 5. 

 27. AGENTCD Cause of death (agent) code. (Core: all remeasured plots when the tree was 

alive at the previous visit and at revisit is dead or removed OR the tree is 

standing dead in the current inventory and the tree is ingrowth, through 

growth, or a missed live tree; Core optional: all initial plot visits when tree 

qualifies as a mortality tree.) When PLOT.MANUAL ≥1.0, this variable was 

collected on only dead and cut trees. When PLOT.MANUAL <1.0, this 

variable was collected on all trees (live, dead, and cut). Cause of damage was 

recorded for live trees if the presence of damage or pathogen activity was 

serious enough to reduce the quality or vigor of the tree. When a tree was 

damaged by more than one agent, the most severe damage was coded. When 

no damage was observed on a live tree, 00 was recorded. Damage recorded 

for dead trees was the cause of death. When the cause of death could not be 

determined for a tree, 99 was recorded. Each FIA program records specific 

codes that may differ from one State to the next. These codes fall within the 

ranges listed below. For the specific codes used in a particular State, contact 

the FIA work unit responsible for that State (table 6). 
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94 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Code Description 

00 No agent recorded (only allowed on live trees in data prior to 1999) 

10 Insect 

20 Disease 

30 Fire 

40 Animal 

50 Weather 

60 Vegetation (e.g., suppression, competition, vines/kudzu) 

70 Unknown/not sure/other – includes death from human activity not related 

to silvicultural or landclearing activity (accidental, random, etc.) TREE 

NOTES required. 

80 Silvicultural or landclearing activity (death caused by harvesting or other 

silvicultural activity, including girdling, chaining, etc., or to landclearing 

activity). 

 

 28. CULL Rotten and missing cull. The percent of the cubic-foot volume in a live or 

dead tally tree that is rotten or missing. This is a calculated value that 

includes field-recorded cull (CULL_FLD) and any additional cull due to 

broken top. 

 29. DAMLOC1 Damage location 1. (Core where PLOT.MANUAL = 1.0 through 1.6; Core 

optional beginning with PLOT.MANUAL = 1.7.) A code indicating where 

damage (meeting or exceeding a severity threshold, as defined in the field 

guide) is present on the tree. 

Code Description 

0 No damage 

1 Roots (exposed) and stump (up to 12 inches from ground level) 

2 Roots, stump, and lower bole 

3 Lower bole (lower half of bole between stump and base of live crown) 

4 Lower and upper bole 

5 Upper bole (upper half of bole between stump and base of live crown) 

6 Crownstem (main stem within the live crown) 

7 Branches (>1 inch diameter at junction with main stem and within the 

live crown) 

8 Buds and shoots of current year 

9 Foliage 

 30. DAMTYP1 Damage type 1. (Core where PLOT.MANUAL = 1.0 through 1.6; Core 

optional beginning with PLOT.MANUAL = 1.7.) A code indicating the kind 

of damage (meeting or exceeding a severity threshold, as defined in the field 

guide) present. If DAMLOC1 = 0, then DAMTYP1 = blank (null). 

Code Description 

01 Canker, gall 

02 Conk, fruiting body, or sign of advanced decay 

03 Open wound 

04 Resinosis or gumosis 

05 Crack or seam 

11 Broken bole or broken root within 3 feet of bole 

12 Broom on root or bole 

13 Broken or dead root further than 3 feet from bole 

20 Vines in the crown 

21 Loss of apical dominance, dead terminal 

22 Broken or dead branches 
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Code Description 

23 Excessive branching or brooms within the live crown 

24 Damaged shoots, buds, or foliage 

25 Discoloration of foliage 

31 Other 

 

 31. DAMSEV1 Damage severity 1. (Core where PLOT.MANUAL = 1.0 through 1.6; Core 

optional beginning with PLOT.MANUAL = 1.7.) A code indicating how 

much of the tree is affected. Valid severity codes vary by damage type and 

damage location and must exceed a threshold value, as defined in the field 

guide. If DAMLOC1 = 0, then DAMSEV1 = blank (null). 

Code Description 

0 01 to 09% of location affected 

1 10 to 19% of location affected 

2 20 to 29% of location affected 

3 30 to 39% of location affected 

4 40 to 49% of location affected 

5 50 to 59% of location affected 

6 60 to 69% of location affected 

7 70 to 79% of location affected 

8 80 to 89% of location affected 

9 90 to 99% of location affected 

 

 32. DAMLOC2 Damage location 2. (Core where PLOT.MANUAL = 1.0 through 1.6; Core 

optional beginning with PLOT.MANUAL = 1.7.) A code indicating where 

secondary damage (meeting or exceeding a severity threshold, as defined in 

the field guide) is present. Use same codes as DAMLOC1. If DAMLOC1 = 0, 

then DAMLOC2 = blank (null) or 0. 

 33. DAMTYP2 Damage type 2. (Core where PLOT.MANUAL = 1.0 through 1.6; Core 

optional beginning with PLOT.MANUAL = 1.7.) A code indicating the kind 

of secondary damage (meeting or exceeding a severity threshold, as defined 

in the field guide) present. Use same codes as DAMTYP1. If DAMLOC1 = 0, 

then DAMTYP2 = blank (null). 

 34. DAMSEV2 Damage severity 2. (Core where PLOT.MANUAL = 1.0 through 1.6; Core 

optional beginning with PLOT.MANUAL = 1.7.) A code indicating how 

much of the tree is affected by the secondary damage. Valid severity codes 

vary by damage type and damage location and must exceed a threshold value, 

as defined in the field guide. Use same codes as DAMSEV1. If DAMLOC1 = 0, 

then DAMSEV2 = blank (null). 

 35. DECAYCD Decay class code. A code indicating the stage of decay in a standing dead 

tree. Populated where PLOT.MANUAL ≥1.0 
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96 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Code Description 

1 All limbs and branches are present; the top of the crown is still present; all 

bark remains; sapwood is intact, with minimal decay; heartwood is sound 

and hard 

2 There are few limbs and no fine branches; the top may be broken; a 

variable amount of bark remains; sapwood is sloughing with advanced 

decay; heartwood is sound at base but beginning to decay in the outer part 

of the upper bole 

3 Only limb stubs exist; the top is broken; a variable amount of bark 

remains; sapwood is sloughing; heartwood has advanced decay in upper 

bole and is beginning at the base 

4 Few or no limb stubs remain; the top is broken; a variable amount of bark 

remains; sapwood is sloughing; heartwood has advanced decay at the base 

and is sloughing in the upper bole 

5 No evidence of branches remains; the top is broken; <20 percent of the 

bark remains; sapwood is gone; heartwood is sloughing throughout 

 

 36. STOCKING Tree stocking. The stocking value computed for each live tree. Stocking 

values are computed using several specific species equations that were 

developed from normal yield tables and stocking charts. Resultant values are 

a function of diameter. The stocking of individual trees is used to calculate 

COND.GSSTK, COND.GSSTKCD, COND.ALSTK, and 

COND.ALSTKCD. 

 37. WDLDSTEM Woodland tree species stem count. The number of live and dead stems used 

to calculate diameter on a woodland tree. Used for tree species where 

diameter is measured at the root collar. For a stem to be counted, it must have 

a minimum stem size of 1 inch in diameter and 1 foot in length. Blank (null) 

if not a woodland species. 

 38. VOLCFNET Net cubic-foot volume. For timber species (trees where the diameter is 

measured at breast height [DBH]), this is the net volume of wood in the 

central stem of a sample tree ≥5.0 inches in diameter, from a 1-foot stump to 

a minimum 4-inch top diameter, or to where the central stem breaks into 

limbs all of which are <4.0 inches in diameter. For woodland species (trees 

where the diameter is measured at root collar [DRC]), VOLCFNET is the net 

volume of wood and bark from the DRC measurement point(s) to a 11⁄2 -inch 

top diameter; includes branches that are at least 11⁄2 inches in diameter along 

the length of the branch. This is a per tree value and must be multiplied by 

TPA_UNADJ to obtain per acre information. This attribute is blank (null) for 

trees with DIA <5.0 inches. All trees measured after 1998 with DIA ≥5.0 

inches (including dead and cut trees) will have entries in this field. Does not 

include rotten, missing, and form cull (volume loss due to rotten, missing, 

and form cull defect has been deducted). 

 39. VOLCFGRS Gross cubic-foot volume. For timber species (trees where the diameter is 

measured at breast height [DBH]), this is the total volume of wood in the 

central stem of sample trees ≥5.0 inches in diameter, from a 1-foot stump to a 

minimum 4-inch top diameter, or to where the central stem breaks into limbs 

all of which are <4.0 inches in diameter. For woodland species (trees where 

the diameter is measured at root collar [DRC]), VOLCFGRS is the total 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 97

volume of wood and bark from the DRC measurement point(s) to a 11⁄2 -inch 

top diameter; includes branches that are at least 11⁄2 inches in diameter along 

the length of the branch. This is a per tree value and must be multiplied by 

TPA_UNADJ to obtain per acre information. This attribute is blank (null) for 

trees with DIA <5.0 inches. All trees measured after 1998 with 

DIA ≥5.0 inches (including dead and cut trees) have entries in this field. 

Includes rotten, missing and form cull (volume loss due to rotten, missing, 

and form cull defect has not been deducted). 

 40. VOLCSNET Net cubic-foot volume in the sawlog portion. The net volume of wood in the 

central stem of a timber species tree of sawtimber size (9.0 inches DIA 

minimum for softwoods, 11.0 inches DIA minimum for hardwoods), from a 

1-foot stump to a minimum top diameter, (7.0 inches for softwoods, 

9.0 inches for hardwoods) or to where the central stem breaks into limbs, all 

of which are less than the minimum top diameter. This is a per tree value and 

must be multiplied by TPA_UNADJ to obtain per acre information. This 

attribute is blank (null) for softwood trees with DIA <9.0 inches (11.0 inches 

for hardwoods). All larger trees have entries in this field if they are growingstock trees (TREECLCD = 2 and STATUSCD = 1). All rough and rotten 

trees (TREECLCD = 3 or 4) and dead and cut trees (STATUSCD = 2 or 3) 

are blank (null) in this field. 

 41. VOLCSGRS Gross cubic-foot volume in the sawlog portion. This is the total volume of 

wood in the central stem of a timber species tree of sawtimber size 

(9.0 inches DIA minimum for softwoods, 11.0 inches DIA minimum for 

hardwoods), from a 1-foot stump to a minimum top diameter (7.0 inches for 

softwoods, 9.0 inches for hardwoods), or to where the central stem breaks 

into limbs, all of which are less than the minimum top diameter. This is a per 

tree value and must be multiplied by TPA_UNADJ to obtain per acre 

information. This attribute is blank (null) for softwood trees with 

DIA <9.0 inches (11.0 inches for hardwoods). All larger trees have entries in 

this field if they are growing-stock trees (TREECLCD = 2 and 

STATUSCD = 1). All rough and rotten trees (TREECLCD = 3 or 4) and dead 

and cut trees (STATUSCD = 2 or 3) are blank (null) in this field. 

 42. VOLBFNET Net board-foot volume in the sawlog portion. This is the net volume 

(International 1⁄4-inch rule) of wood in the central stem of a timber species 

tree of sawtimber size (9.0 inches DIA minimum for softwoods, 11.0 inches 

DIA minimum for hardwoods), from a 1-foot stump to a minimum top 

diameter (7.0 inches for softwoods, 9.0 inches for hardwoods), or to where 

the central stem breaks into limbs all of which are less than the minimum top 

diameter. This is a per tree value and must be multiplied by TPA_UNADJ to 

obtain per unit area information. This attribute is blank (null) for softwood 

trees with DIA <9.0 inches (11.0 inches for hardwoods). All larger trees 

should have entries in this field if they are growing-stock trees (TREECLCD 

= 2 and STATUSCD = 1). All rough and rotten trees (TREECLCD = 3 or 4) 

and dead and cut trees (STATUSCD = 2 or 3) are blank (null) in this field. 
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98 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 43. VOLBFGRS Gross board-foot volume in the sawlog portion. This is the total volume 

(International 1⁄4-inch rule) of wood in the central stem of a timber species 

tree of sawtimber size (9.0 inches DIA minimum for softwoods, 11.0 inches 

DIA minimum for hardwoods), from a 1-foot stump to a minimum top 

diameter (7.0 inches for softwoods, 9.0 inches for hardwoods), or to where 

the central stem breaks into limbs all of which are less than the minimum top 

DIA. This is a per tree value and must be multiplied by TPA_UNADJ to 

obtain per unit area information. This attribute is blank (null) for softwood 

trees with DIA <9.0 inches (11.0 inches for hardwoods). All larger trees 

should have entries in this field if they are growing-stock trees (TREECLCD 

= 2 and STATUSCD = 1). All rough and rotten trees (TREECLCD = 3 or 4) 

and dead and cut trees (STATUSCD = 2 or 3) are blank (null) in this field. 

 44. VOLCFSND Sound cubic-foot volume. For timber species (trees where the diameter is 

measured at breast height [DBH]), the volume of sound wood in the central 

stem of a sample tree ≥5.0 inches in diameter from a 1-foot stump to a 

minimum 4-inch top diameter or to where the central stem breaks into limbs 

all of which are <4.0 inches in diameter. For woodland species (trees where 

the diameter is measured at root collar [DRC]), VOLCFSND is the net 

volume of wood and bark from the DRC measurement point(s) to a minimum 

11⁄2 -inch top diameter; includes branches that are at least 11⁄2 inches in 

diameter along the length of the branch. This is a per tree value and must be 

multiplied by TPA_UNADJ to obtain per acre information. This attribute is 

blank (null) for trees with DIA <5.0 inches. All trees with DIA ≥5.0 inches 

(including dead trees) have entries in this field. Does not include rotten and 

missing cull (volume loss due to rotten and missing cull defect has been 

deducted). 

 45. GROWCFGS Net annual merchantable cubic-foot growth of a growing-stock tree on 

timberland. This is the net change in cubic-foot volume per year of this tree 

(for remeasured plots, (V2

- V1)/(t2- t1); where 1 and 2 denote the past and 

current measurement, respectively, V is volume, and t indicates year of 

measurement). Because this value is net growth, it may be a negative 

number. Negative growth values are usually due to mortality (V2 = 0) but can 

also occur on live trees that have a net loss in volume because of damage, rot, 

broken top, or other causes. To expand to a per acre value, multiply by 

TPAGROW_UNADJ. 

 46. GROWBFSL Net annual merchantable board-foot growth of a sawtimber size tree on 

timberland. This is the net change in board-foot (International 1⁄4-inch rule) 

volume per year of this tree (for remeasured plots (V2

- V1)/(t2- t1)). Because 

this value is net growth, it may be a negative number. Negative growth 

values are usually due to mortality (V2 = 0) but can also occur on live trees 

that have a net loss in volume because of damage, rot, broken top, or other 

causes. To expand to a per acre value, multiply by TPAGROW_UNADJ. 

 47. GROWCFAL Net annual sound cubic-foot growth of a live tree on timberland. The net 

change in cubic-foot volume per year of this tree (for remeasured plots 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 99

(V2

- V1)/(t2 - t1)). Because this value is net growth, it may be a negative 

number. Negative growth values are usually due to mortality (V2 = 0) but can 

also occur on live trees that have a net loss in volume because of damage, rot, 

broken top, or other causes. To expand to a per acre value, multiply by 

TPAGROW_UNADJ. GROWCFAL differs from GROWCFGS by including 

all trees, regardless of tree class. 

 48. MORTCFGS Cubic-foot volume of a growing-stock tree on timberland for mortality 

purposes. Represents the cubic-foot volume of a growing-stock tree at time of 

death. To obtain estimates of annual per acre mortality, multiply by 

TPAMORT_UNADJ. 

 49. MORTBFSL Board-foot volume of a sawtimber size tree on timberland for mortality 

purposes. Represents the board-foot (International 1⁄4-inch rule) volume of a 

sawtimber tree at time of mortality. To obtain estimates of annual per acre 

mortality, multiply by TPAMORT_UNADJ. 

 50. MORTCFAL Sound cubic-foot volume of a tree on timberland for mortality purposes. 

Represents the cubic-foot volume of the tree at time of mortality. To obtain 

estimates of annual per acre mortality, multiply by TPAMORT_UNADJ. 

MORTCFAL differs from MORTCFGS by including all trees, regardless of 

tree class. 

 51. REMVCFGS Cubic-foot volume of a growing-stock tree on timberland for removal 

purposes. Represents the cubic-foot volume of the tree at time of removal. To 

obtain estimates of annual per acre removals, multiply by 

TPAREMV_UNADJ. 

 52. REMVBFSL Board-foot volume of a sawtimber size tree on timberland for removal 

purposes. Represents the board-foot (International 1⁄4-inch rule) volume of the 

tree at time of removal. To obtain estimates of annual per acre removals, 

multiply by TPAREMV_UNADJ. 

 53. REMVCFAL Sound cubic-foot volume of a tree on timberland for removal purposes. 

Represents the cubic-foot volume of the tree at time of removal. To obtain 

estimates of annual per acre removals, multiply by TPAREMV_UNADJ. 

REMVCFAL differs from REMVCFGS by including all trees, regardless of 

tree class. 

 54. DIACHECK Diameter check code. A code indicating the reliability of the diameter 

measurement. 

Code Description 

0 Diameter accurately measured 

1 Diameter estimated 

2 Diameter measured at different location than previous measurement 

(remeasurement trees only) 

5 Diameter modeled in the office (used with periodic inventories) 

Note: If both codes 1 and 2 apply, code 2 is used. 
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100 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 55. MORTYR Mortality year. (Core optional.) The estimated year in which a remeasured 

tree died or was cut. Populated where PLOT.MANUAL ≥1.0 and populated 

by some FIA work units where PLOT.MANUAL <1.0. 

 56. SALVCD Salvable dead code. A standing or down dead tree considered merchantable 

by regional standards. Contact the appropriate FIA work unit for information 

on how this code is assigned for a particular State (table 6). 

Code Description 

0 Dead not salvable 

1 Dead salvable 

 

 57. UNCRCD Uncompacted live crown ratio. (Core optional Phase 2: ≥5.0-inch live trees; 

Core Phase 3: ≥1.0-inch live trees.) Percentage determined by dividing the 

live crown length by the actual tree length. When PLOT.MANUAL <3.0 the 

variable was a code, which was converted to the midpoint of the ranges 

represented by the codes, and is stored as a percentage. 

 58. CPOSCD Crown position code. (Core on Phase 3 plots only.) The relative position of 

each tree in relation to the overstory canopy. 

Code Description 

1 Superstory 

2 Overstory 

3 Understory 

4 Open canopy 

 59. CLIGHTCD Crown light exposure code. (Core optional on Phase 2 plots; Core on Phase 

3 plots only.) A code indicating the amount of light being received by the tree 

crown. Collected for all live trees at least 5 inches DBH/DRC. Trees with 

UNCRCD <35 have a maximum CLIGHTCD of 1. 

Code Description 

0 The tree receives no direct sunlight because it is shaded by adjacent trees or 

other vegetation 

1 Receives full light from the top or 1 side 

2 Receives full light from the top and 1 side (or 2 sides without the top) 

3 Receives full light from the top and 2 sides (or 3 sides without the top) 

4 Receives full light from the top and 3 sides 

5 Receives full light from the top and 4 sides 

 60. CVIGORCD Crown vigor code. (Core optional on Phase 2 plots; Core on Phase 3 plots 

only.) A code indicating the vigor of sapling crowns. Collected for live trees 

between 1 and 4.9 inches DBH/DRC. 
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Code Description 

1 Saplings must have an uncompacted live crown ratio of 35 or higher, have 

<5 percent dieback (deer/rabbit browse is not considered as dieback but is 

considered missing foliage) and 80 percent or more of the foliage present is 

normal or at least 50 percent of each leaf is not damaged or missing. Twigs 

and branches that are dead because of normal shading are not included. 

2 Saplings do not meet class 1 or 3 criteria. They may have any uncompacted 

live crown ratio, may or may not have dieback and may have between 21 

and 100 percent of the foliage classified as normal. 

3 Saplings may have any uncompacted live crown ratio and have 1 to 20 

percent normal foliage or the percent of foliage missing combined with the 

percent of leaves that are over 50 percent damaged or missing should equal 

80 percent or more of the live crown. Twigs and branches that are dead 

because of normal shading are not included. Code is also used for saplings 

that have no crown by definition 

 61. CDENCD Crown density code. (Core optional on Phase 2 plots; Core on Phase 3 plots 

only.) A code indicating how dense the tree crown is, estimated in percent 

classes. Collected for all live trees at least 5 inches DBH/DRC. Crown 

density is the amount of crown branches, foliage and reproductive structures 

that blocks light visibility through the crown. 

Code Description 

00 0% 

05 1-5% 

10 6-10% 

15 11-15% 

. . 

. . 

. . 

95 91-95% 

99 96-100% 

 62. CDIEBKCD Crown dieback code. (Core optional on Phase 2 plots; Core on Phase 3 plots 

only.) A code indicating the amount of recent dead material in the upper and 

outer portion of the crown, estimated in percent classes. Collected for all live 

trees at least 5 inches DBH/DRC. 

Code Description 

00 0% 

05 1-5% 

10 6-10% 

15 11-15% 

. . 

. . 

. . 

95 91-95% 

99 96-100% 

 63. TRANSCD Foliage transparency code. (Core optional on Phase 2 plots; Core on Phase 3 

plots only.) A code indicating the amount of light penetrating the foliated 

portion of the crown, estimated in percent classes. Collected for all live trees 

at least 5 inches DBH/DRC. 
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102 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Code Description 

00 0% 

05 1-5% 

10 6-10% 

15 11-15% 

. . 

. . 

. . 

95 91-95% 

99 96-100% 

 64. TREEHISTCD Tree history code. Identifies the tree with detailed information as to whether 

the tree is live, dead, cut, removed due to land use change, etc. Contact the 

appropriate FIA work unit for the definitions (table 6). Only collected by 

certain FIA units (SURVEY.RSCD = 23, 24, or 33). 

 65. DIACALC Current diameter calculated. If the diameter is unmeasurable (i.e., the tree is 

cut or dead), the diameter is calculated (in inches) and stored in this variable. 

Only collected by certain FIA work units (SURVEY.RSCD = 23 or 33). 

 66. BHAGE Breast height age. The age of a live tree derived from counting tree rings 

from an increment core sample extracted at a height of 4.5 feet above ground. 

Breast height age is collected for a subset of trees and only for trees that the 

diameter is measured at breast height (DBH). This data item is used to 

calculate classification variables such as stand age. For PNWRS, one tree is 

sampled for BHAGE for each species, within each crown class, and for each 

condition class present on a plot. Age of saplings (<5.0 inches DBH) may be 

aged by counting branch whorls above 4.5 feet. No timber hardwood species 

other than red alder are bored for age. For RMRS, one tree is sampled for 

each species and broad diameter class present on a plot. Only collected by 

certain FIA work units (SURVEY.RSCD = 22 or 26) and is left blank (null) 

when it is not collected. 

 67. TOTAGE Total age. The age of a live tree derived either from counting tree rings from 

an increment core sample extracted at the base of a tree where diameter is 

measured at root collar (DRC), or for small saplings (1.0 to 2.9 inches DBH) 

by counting all branch whorls, or by adding a species-dependent number of 

years to breast height age. Total age is collected for a subset of trees and is 

used to calculate classification variables such as stand age. Only collected by 

certain FIA work units (SURVEY.RSCD = 22 or 26) and is left blank (null) 

when it is not collected. 

 68. CULLDEAD Dead cull. The percent of the gross cubic-foot volume that is cull due to 

sound dead material. Recorded for all trees that are at least 5.0 inches in 

diameter. Only collected by certain FIA work units (SURVEY.RSCD = 22). 

This attribute is blank (null) for trees smaller than 5 inches and is always null 

for the other FIA work units. 

 69. CULLFORM Form cull. The percent of the gross cubic-foot volume that is cull due to form 

defect. Recorded for live trees that are at least 5.0 inches DBH. Only 
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collected by certain FIA work units (SURVEY.RSCD = 22). This attribute is 

blank (null) for dead trees, trees smaller than 5 inches DBH, for all trees 

where the diameter is measured at root collar (DRC), and is always null for 

the other FIA work units. 

 70. CULLMSTOP Missing top cull. The percent of the gross cubic-foot volume that is cull due 

to a missing (broken) merchantable top. Recorded for trees that are at least 

5.0 inches in diameter. The volume estimate does not include any portion of 

the missing top that is <4.0 inches DOB (diameter outside bark). Many 

broken top trees may have 0% missing top cull because no merchantable 

volume was lost. Only collected by certain FIA work units (SURVEY.RSCD 

= 22). This attribute is blank (null) for trees smaller than 5 inches diameter 

and is always null for the other FIA work units. 

 71. CULLBF Board-foot cull. The percent of the gross board-foot volume that is cull due to 

rot or form. Only collected by certain FIA work units (SURVEY.RSCD = 24). 

 72. CULLCF Cubic-foot cull. The percent of the gross cubic-foot volume that is cull due to 

rot or form. Only collected by certain FIA work units (SURVEY.RSCD = 24). 

 73. BFSND Board-foot-cull soundness. The percent of the board-foot cull that is sound 

(due to form). Only collected by certain FIA work units (SURVEY.RSCD = 24). 

 74. CFSND Cubic-foot-cull soundness. The percent of the cubic-foot cull that is sound 

(due to form). Only collected by certain FIA work units (SURVEY.RSCD = 24). 

 75. SAWHT Sawlog height. The length (height) of a tree, recorded to a 7-inch top (9-inch 

for hardwoods), where at least one 8-foot log, merchantable or not, is present. 

On broken topped trees, sawlog length is recorded to the point of the break. 

Only collected by certain FIA work units (SURVEY.RSCD = 24). 

 76. BOLEHT Bole height. The length (height) of a tree, recorded to a 4-inch top, where at 

least one 4-foot section is present. Only collected by certain FIA work units 

(SURVEY.RSCD = 24). 

 77. FORMCL Form class. A code used in calculating merchantable bole net volume. 

Recorded for all live hardwood trees tallied that are ≥5.0 inch DBH/DRC. 

Also recorded for conifers ≥5.0 inch DBH in Region 5 National Forests. Only 

collected by certain FIA work units (SURVEY.RSCD = 26). 

Code Description 

1 First 8 feet above stump is straight 

2 First 8 feet above stump is NOT straight or forked; but there is at least one 

straight 8-foot log elsewhere in the tree 

3 No 8-foot logs anywhere in the tree now or in the future due to form 

 78. HTCALC Current height calculated. If the height is unmeasurable (i.e., the tree is cut or 

dead), the height is calculated (in feet) and stored in this variable. Only 

collected by certain FIA work units (SURVEY.RSCD = 33). 
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104 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 79. HRDWD_CLUMP_CD 

 Hardwood clump code. A code sequentially assigned to each hardwood 

clump within each species as they are found on a subplot. Up to 9 hardwood 

clumps can be identified and coded within each species on each subplot. A 

clump is defined as having 3 or more live stems originating from a common 

point on the root system. Western woodland hardwood species are not 

evaluated for clump code. Clump code data are used to adjust stocking 

estimates since trees growing in clumps contribute less to stocking than do 

individual trees. Only collected by certain FIA work units (SURVEY.RSCD 

= 26). 

 80. SITREE Calculated site index. Computed for every tree. The site index represents the 

average total length (in feet) that dominant and co-dominant trees in fullystocked, even-aged stands (of the same species as this tree) will obtain at key 

ages (usually 25 or 50 years). Only collected by certain FIA work units 

(SURVEY.RSCD = 23). 

 81. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 82. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 83. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 84. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 85. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 
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 86. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 

 87. MORTCD Mortality code. (Core optional.) Used for a tree that was alive within past 5 

years, but has died. 

Code Description 

0 Tree does not qualify as mortality 

1 Tree does qualify as mortality 

 88. HTDMP Height to diameter measurement point. (Core optional.) For trees measured 

directly at 4.5 feet above ground, this item is blank (null). If the diameter is 

not measured at 4.5 feet, the actual length from the ground, to the nearest 

0.1 foot, at which the diameter was measured for each tally tree, 1.0-inch 

DBH and larger. 

 89. ROUGHCULL Rough cull. (Core optional.) Percentage of sound dead cull, as a percent of 

the merchantable bole/portion of the tree. 

 90. MIST_CL_CD Mistletoe class code. (Core optional.) A rating of dwarf mistletoe infection. 

Recorded on all live conifer species except juniper. Using the Hawksworth 

(1979) six-class rating system, the live crown is divided into thirds, and each 

third is rated using the following scale: 0 is for no visible infection, 

1 for <50 percent of branches infected, 2 for >50 percent of branches 

infected. The ratings for each third are summed together to yield the 

Hawksworth rating. 

Code Description 

0 Hawksworth tree DMR rating of 0, no infection 

1 Hawksworth tree DMR rating of 1, light infection 

2 Hawksworth tree DMR rating of 2, light infection 

3 Hawksworth tree DMR rating of 3, medium infection 

4 Hawksworth tree DMR rating of 4, medium infection 

5 Hawksworth tree DMR rating of 5, heavy infection 

6 Hawksworth tree DMR rating of 6, heavy infection 

 91. CULL_FLD Rotten/missing cull, field -recorded. (Core: ≥5.0-inch live trees; Core 

optional: ≥5.0-inch standing dead trees.) The percentage rotten or missing 

cubic-foot cull volume, estimated to the nearest 1 percent. This estimate does 

not include any cull estimate above actual length; therefore volume lost from 

a broken top is not included (see CULL for percent cull including cull from 

broken top). When field crews estimate volume loss (tree cull), they only 

consider the cull on the merchantable bole/portion of the tree, from a 1-foot 

stump to a 4-inch top diameter outside bark (DOB). For western woodland 

species, the merchantable portion is between the point of DRC measurement 

to a 1.5-inch top DOB. 
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106 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 92. RECONCILECD 

 Reconcile code. Recorded for remeasurement locations only. A code 

indicating the reason a tree either enters or is no longer a part of the 

inventory. 

Code Description 

1 Ingrowth or reversions – either a new tally tree not qualifying as through 

growth or a new tree on land that was formerly nonforest and now qualifies as 

forest land (includes reversion or encroachments). 

2 Through growth – new tally tree 5 inches DBH/DRC and larger, within the 

microplot, which was not missed at the previous inventory. 

3 Missed live – a live tree missed at previous inventory and that is live, dead, or 

removed now. 

4 Missed dead – a dead tree missed at previous inventory and that is dead or 

removed now. 

5 Shrank – live tree that shrunk below threshold diameter on 

microplot/subplot/macroplot plot. 

6 Missing (moved) – tree was correctly tallied in previous inventory, but has 

now moved beyond the radius of the plot due to natural causes (i.e., small 

earth movement, hurricane). Tree must be either live before and still alive 

now or dead before and dead now. If tree was live before and now dead, this 

is a mortality tree and should have STATUSCD = 2 (not 0). 

7 Cruiser error – erroneously tallied at previous inventory 

8 Procedural change – tree was tallied at the previous inventory, but is no 

longer tallied due to a definition or procedural change. 

9 Tree was sampled before, but now the area where the tree was located is 

nonsampled. All trees on the nonsampled area have RECONCILECD = 9. 

 93. PREVDIA Previous diameter. The previous diameter (in inches) of the sample tree at the 

point of diameter measurement. Populated for remeasured trees. 

 94. FGROWCFGS Net annual merchantable cubic-foot growth of a growing-stock tree on forest 

land. This is the net change in cubic-foot volume per year of this tree (for 

remeasured plots, (V2 - V1

)/(t2 - t1); where 1 and 2 denote the past and current 

measurement, respectively, V is volume, t indicates date of measurement, and 

t2 – t1 = PLOT.REMPER). Because this value is net growth, it may be a 

negative number. Negative growth values are usually due to mortality 

(V2 = 0) but can also occur on live trees that have a net loss in volume 

because of damage, rot, broken top, or other causes. To expand to a per acre 

value, multiply by TPAGROW_UNADJ. 

 95. FGROWBFSL Net annual merchantable board-foot growth of a sawtimber tree on forest 

land. This is the net change in board-foot (International 1⁄4 -inch rule) volume 

per year of this tree (for remeasured plots (V2 - V1

)/(t2-t1)). Because this value 

is net growth, it may be a negative number. Negative growth values are 

usually due to mortality (V2

 = 0) but can also occur on live trees that have a 

net loss in volume because of damage, rot, broken top, or other causes. To 

expand to a per acre value, multiply by TPAGROW_UNADJ. 

 96. FGROWCFAL Net annual sound cubic-foot growth of a live tree on forest land. The net 

change in cubic-foot volume per year of this tree (for remeasured plots 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 107

(V2 - V1

)/(t2 - t1)). Because this value is net growth, it may be a negative 

number. Negative growth values are usually due to mortality (V2

 = 0) but can 

also occur on live trees that have a net loss in volume because of damage, rot, 

broken top, or other causes. To expand to a per acre value, multiply by 

TPAGROW_UNADJ. FGROWCFAL differs from FGROWCFGS by 

including all trees, regardless of tree class. 

 97. FMORTCFGS Cubic-foot volume of a growing-stock tree for mortality purposes on forest 

land. Represents the cubic-foot volume of a growing-stock tree at time of 

mortality. To obtain estimates of annual per acre mortality, multiply by 

TPAMORT_UNADJ. 

 98. FMORTBFSL Board-foot volume of a sawtimber tree for mortality purposes on forest land. 

Represents the board-foot (International 1⁄4-rule) volume of a sawtimber tree 

at time of mortality. To obtain estimates of annual per acre mortality, 

multiply by TPAMORT_UNADJ. 

 99. FMORTCFAL Sound cubic-foot volume of a tree for mortality purposes on forest land. 

Represents the cubic-foot volume of the tree at time of mortality. To obtain 

estimates of annual per acre mortality, multiply by TPAMORT_UNADJ. 

FMORTCFAL differs from FMORTCFGS by including all trees, regardless 

of tree class. 

100. FREMVCFGS Cubic-foot volume of a growing-stock tree for removal purposes on forest 

land. Represents the cubic-foot volume of the tree at time of removal. To 

obtain estimates of annual per acre removals, multiply by 

TPAREMV_UNADJ. 

101. FREMVBFSL Board-foot volume of a sawtimber size tree for removal purposes on forest 

land. Represents the board-foot (International 1⁄4-rule) volume of the tree at 

time of removal. To obtain estimates of annual per acre removals, multiply 

by TPAREMV_UNADJ. 

102. FREMVCFAL Sound cubic-foot volume of the tree for removal purposes on forest land. 

Represents the cubic-foot volume of the tree at time of removal. To obtain 

estimates of annual per acre removals, multiply by TPAREMV_UNADJ. 

FREMVCFAL differs from FREMVCFGS by including all trees, regardless 

of tree class. 

103. P2A_GRM_FLG 

 Periodic to annual growth, removal, and mortality flag. A code indicating if 

this tree is part of a periodic inventory (usually from a variable-radius plot 

design) that is only included for the purposes of computing growth, removals 

and/or mortality estimates. This tree does not contribute to current estimates 

of such attributes as volume, biomass or number of trees. The flag is set to Y 

for those trees that are needed for estimation and otherwise is left blank 

(null). 
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108 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

104. TREECLCD_NERS 

 Tree class code, Northeastern Research Station. In annual inventory, this 

code represents a classification of the overall quality of a tree that is 5.0 

inches DBH and larger. It classifies the quality of a sawtimber tree based on 

the present condition, or it classifies the quality of a poletimber tree as a 

prospective determination (i.e., a forecast of potential quality when and if the 

tree becomes sawtimber size). For more detailed description, see the regional 

field guide. Only collected by certain FIA work units (SURVEY.RSCD = 24). 

Code Description 

1 Preferred – Live tree that would be favored in cultural operations. Mature tree, that 

is older than the rest of the stand; has less than 20 percent total board foot cull; is 

expected to live for 5 more years: and is a low risk tree. In general, the tree has the 

following qualifications: 

• must be free from “general” damage (i.e., damages that would now or 

prospectively cause a reduction of tree class, significantly deter growth, or 

prevent it from producing marketable products in the next 5 years). 

• should have no more than 10 percent board-foot cull due to form defect. 

• should have good vigor, usually indicated by a crown ratio of 30 percent 

or more and dominant or co-dominant. 

• usually has a grade 1 butt log. 

2 Acceptable – This class includes: 

• live sawtimber tree that does not qualify as a preferred tree but is not a cull 

tree (see Rough and Rotten Cull). 

• live poletimber tree that prospectively will not qualify as a preferred tree, 

but is not now or prospectively a cull tree (see Rough and Rotten Cull). 

3 Rough Cull – This class includes: 

• live sawtimber tree that currently has 67 percent or more predominantly 

sound board-foot cull; or does not contain one merchantable 12-foot 

sawlog or two non-contiguous merchantable 8-foot sawlogs. 

• live poletimber tree that currently has 67 percent or more predominantly 

sound cubic-foot cull; or prospectively will have 67 percent or more 

predominantly sound board-foot cull; or will not contain one merchantable 

12-foot sawlog or two noncontiguous merchantable 8-foot sawlogs. 

4 Rotten Cull – This class includes: 

• live sawtimber tree that currently has 67 percent or more predominantly 

unsound board-foot cull. 

• live poletimber tree that currently has 67 percent or more predominantly 

unsound cubic-foot cull; or prospectively will have 67 percent or more 

predominantly unsound board-foot cull. 

5 Dead – Tree that has recently died (within the last several years); but still retains 

many branches (including some small branches and possibly some fine twigs); and 

has bark that is generally tight and hard to remove from the tree. 

6 Snag – Dead tree, or what remains of a dead tree, that is at least 4.5 feet tall and is 

missing most of its bark. This category includes a tree covered with bark that is 

very loose. This bark can usually be removed, often times in big strips, with very 

little effort. A snag is not a recently dead tree. Most often, it has been dead for 

several years – sometimes, for more than a decade. 

 105. TREECLCD_SRS 

 Tree class code, Southern Research Station. A code indicating the general 

quality of the tree. Prior to the merger of the Southern and Southeastern 

Research Stations (INVYR ≤1997), growing-stock (code 2) was only 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 109

assigned to species that were considered to have commercial value. Since the 

merger (INVYR >1997), code 2 has been applied to all tree species meeting 

the growing-stock form, grade, size and soundness requirements, regardless 

of commercial value. Only collected by certain FIA work units 

(SURVEY.RSCD = 33). 

Code Description 

2 Growing-stock – All trees that have at least one 12-foot log or two 8-foot 

logs that meet grade and size requirements and at least 1⁄3 of the total 

board foot volume is merchantable. Poletimber-sized trees are evaluated 

based on their potential. 

3 Rough cull – Trees that do not contain at least one 12-foot log or two 

8-foot logs, or more than 1⁄3 of the total board foot volume is not 

merchantable, primarily due to roughness or poor form. 

4 Rotten cull: Trees that do not contain at least one 12-foot log or two 

8-foot logs, or more than 1⁄3 of the total board foot volume is not 

merchantable, primarily due to rotten, unsound wood. 

106. TREECLCD_NCRS 

 Tree class code, North Central Research Station. In annual inventory, a code 

indicating tree suitability for timber products, or the extent of decay in the 

butt section of down-dead trees. It is recorded on live standing, standingdead, and down dead trees that are 1.0 inches DBH and larger. Tree class is 

basically a check for the straightness and soundness of the sawlog portion on 

a sawtimber tree or the potential sawlog portion on a poletimber tree or 

sapling. “Sawlog portion” is defined as the length between the 1-foot stump 

and the 9.0-inch top diameter of outside bark, DOB, for hardwoods, or the 

7.0-inch top DOB for softwoods. For more detailed description, see the 

regional field guide http://www.nrs.fs.fed.us/fia/data-collection/. Only 

collected by certain FIA work units (SURVEY.RSCD = 23). 
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110 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Code Description 

20 Growing-stock – Any live tree of commercial species that is saw-timber 

size and has at least one merchantable 12-foot sawlog or two merchantable 

8-foot sawlogs meeting minimum log-grade requirements. At least onethird of the gross board-foot volume of the sawlog portion must be 

merchantable material. A merchantable sawlog must be at least 50 percent 

sound at any point. Any pole timber size tree that has the potential to meet 

the above specifications. 

30 Rough Cull, Salvable, and Salvable-down – Includes any tree of 

noncommercial species, or any tree that is saw-timber size and has no 

merchantable sawlog. Over one-half of the volume in the sawlog portion 

does not meet minimum log-grade specifications due to roughness, 

excessive sweep or crook, splits, cracks, limbs, or forks. Rough cull polesize trees do not have the potential to meet the specifications for growingstock because of forks, limb stoppers, or excessive sweep or crook. A 

down-dead tree ≥5.0-inch DBH that meets these standards is given a 

tree/decay code of 30. 

31 Short-log Cull – Any live saw-timber-size tree of commercial species that 

has at least one 8-foot sawlog, but less than a 12-foot sawlog, meeting 

minimum log-grade specifications. Any live saw-timber-size tree of 

commercial species that has less than one-third of the volume of the 

sawlog portion in merchantable logs, but has at least one 8-foot or longer 

sawlog meeting minimum log-grade specifications. A short sawlog must 

be 50 percent sound at any point. Pole-size trees never receive a tree class 

code 31. 

40 Rotten Cull – Any live tree of commercial species that is saw-timber size 

and has no merchantable sawlog. Over one-half of the volume in the 

sawlog portion does not meet minimum log-grade specifications primarily 

because of rot, missing sections, or deadwood. Classify any pole-size tree 

that does not have the potential to meet the specifications for growingstock because of rot as rotten cull. Assume that all live trees will 

eventually attain sawlog size at DBH. Predicted death, tree vigor, and plot 

site index are not considered in determining tree class. A standing-dead 

tree without an 8-foot or longer section that is at least 50 percent sound 

has a tree class of 40. On remeasurement of a sapling, if it has died and is 

still standing it is given a tree class of 40. 

107. TREECLCD_RMRS 

 Tree class code, Rocky Mountain Research Station. A code indicating the 

general quality of the tree. Only collected by certain FIA work units 

(SURVEY.RSCD = 22). 

Code Description 

1 Sound-live timber species – All live timber trees (species with diameter 

measured at breast height) that meet minimum merchantability standards. 

In general, these trees have at least one solid 8-foot section, are 

reasonably free of form defect on the merchantable bole, and at least 34 

percent or more of the volume is merchantable. Excludes rough or rotten 

cull timber trees. 

2 All live woodland species – All live woodland trees (species with 

diameter measured at root collar). All trees assigned to species groups 23 

and 48 belong in this category (see appendix G). 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 111

Code Description 

3 Rough-live timber species – All live trees that do not now, or 

prospectively, have at least one solid 8-foot section, reasonably free of 

form defect on the merchantable bole, or have 67 percent or more of the 

merchantable volume cull; and more than half of this cull is due to sound 

dead wood cubic-foot loss or severe form defect volume loss. 

4 Rotten-live timber species – All live trees with 67 percent or more of the 

merchantable volume cull, and more than half of this cull is due to rotten 

or missing cubic-foot volume loss. 

5 Hard (salvable) dead – dead trees that have less than 67 percent of the 

volume cull due to rotten or missing cubic-foot volume loss. 

6 Soft (nonsalvable) dead – dead trees that have 67 percent or more of the 

volume cull due to rotten or missing cubic-foot volume loss. 

108. STANDING_DEAD_CD 

Standing dead code. A code indicating if a tree qualifies as standing dead. To 

qualify as a standing dead tally tree, the dead tree must be at least 5.0 inches 

in diameter, have a bole that has an unbroken actual length of at least 4.5 feet, 

and lean less than 45 degrees from vertical as measured from the base of the 

tree to 4.5 feet. Populated where PLOT.MANUAL ≥2.0; may be populated 

using information collected on dead trees in earlier inventories for dead trees. 

For western woodland species with multiple stems, a tree is considered down 

if more than 2⁄3 of the volume is no longer attached or upright; cut and 

removed volume is not considered. For western woodland species with single 

stems to qualify as a standing dead tally tree, dead trees must be at least 

5.0 inches in diameter, be at least 1.0 foot in unbroken ACTUAL LENGTH, 

and lean less than 45 degrees from vertical. 

Code Description 

0 No – tree does not qualify as standing dead 

1 Yes – tree does qualify as standing dead 

109. PREV_STATUS_CD 

 Previous tree status code. Tree status that was recorded at the previous 

inventory on all tally trees ≥1.0 inch in diameter. 

Code Description 

1 Live tree – live tree at the previous inventory 

2 Dead tree – standing dead at the previous inventory 

110. PREV_WDLDSTEM 

 Previous woodland stem count. Woodland tree species stem count that was 

recorded at the previous inventory. 

111. TPA_UNADJ Trees per acre unadjusted. The number of trees per acre that the sample tree 

theoretically represents based on the sample design. For fixed radius plots 

taken with the mapped plot design (PLOT.DESIGNCD = 1), TPA_UNADJ is 

set to a constant derived from the plot size and equals 6.018046 for trees 

sampled on subplots, 74.965282 for trees sampled on microplots, and 
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112 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

0.999188 for trees sampled on macroplots. Variable radius plots were often 

used in earlier inventories, so the value in TPA_UNADJ decreases as the tree 

diameter increases. Based on the procedures described in Bechtold and 

Patterson (2005), this attribute can be adjusted using factors stored on the 

POP_STRATUM table to derive population estimates. Examples of 

estimating population totals are shown in chapter 4. 

112. TPAMORT_UNADJ 

 Mortality trees per acre unadjusted. The number of mortality trees per acre 

per year that the sample tree theoretically represents based on the sample 

design. For fixed radius plots taken with the mapped plot design 

(PLOT.DESIGNCD =1), TPAMORT_UNADJ is set to a constant derived 

from the plot size divided by PLOT.REMPER. Variable radius plots were 

often used in earlier inventories, so the value in TPAMORT_UNADJ 

decreases as the tree diameter increases. This attribute will be blank (null) if 

the tree does not contribute to mortality estimates. Based on the procedures 

described in Bechtold and Patterson (2005), this attribute can be adjusted 

using factors stored on the POP_STRATUM table to derive population 

estimates. Examples of estimating population totals are shown in chapter 4. 

 113. TPAREMV_UNADJ 

 Removal trees per acre unadjusted. The number of removal trees per acre per 

year that the sample tree theoretically represents based on the sample design. 

For fixed radius plots taken with the mapped plot design (PLOT.DESIGNCD 

=1), TPAREMV_UNADJ is set to a constant derived from the plot size 

divided by PLOT.REMPER. Variable radius plots were often used in earlier 

inventories, so the value in TPAREMV_UNADJ decreases as the tree 

diameter increases. This attribute will be blank (null) if the tree does not 

contribute to removals estimates. Based on the procedures described in 

Bechtold and Patterson (2005), this attribute can be adjusted using factors 

stored on the POP_STRATUM table to derive population estimates. 

Examples of estimating population totals are shown in chapter 4. 

114. TPAGROW_UNADJ 

 Growth trees per acre unadjusted. The number of growth trees per acre that 

the sample tree theoretically represents based on the sample design. For fixed 

radius plots taken with the mapped plot design (PLOT.DESIGNCD = 1), 

TPAGROW_UNADJ is set to a constant derived from the plot size. Variable 

radius plots were often used in earlier inventories, so the value in 

TPAGROW_UNADJ decreases as the tree diameter increases. This attribute 

will be blank (null) if the tree does not contribute to growth estimates. Based 

on the procedures described in Bechtold and Patterson (2005), this attribute 

can be adjusted using factors stored on the POP_STRATUM table to derive 

population estimates. Examples of estimating population totals are shown in 

chapter 4. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 113

115. DRYBIO_BOLE 

 Dry biomass in the merchantable bole. The oven-dry biomass (pounds) in the 

merchantable bole of timber species [trees where diameter is measured at 

breast height (DBH)] ≥5 inches in diameter. This is the biomass of sound 

wood in live and dead trees, including bark, from a 1-foot stump to a 

minimum 4-inch top diameter of the central stem. This is a per tree value and 

must be multiplied by TPA_UNADJ to obtain per acre information. This 

attribute is blank (null) for timber species with DIA <5.0 inches and for 

woodland species. See DRYBIO_WDLD_SPP for biomass of woodland 

species and DRYBIO_SAPLING for biomass of timber species with 

DIA <5 inches. For dead or cut timber trees, this number represents the 

biomass at the time of death or last measurement. DRYBIO_BOLE is based 

on VOLCFSND and specific gravity information derived by the Forest 

Products Lab and others (values stored in the REF_SPECIES table). If 

VOLCFSND is not available, then either VOLCFGRS * Percent Sound or 

VOLCFNET * (average ratio of cubic foot sound to cubic foot net volume, 

calculated as national averages by species group and diameter) is used. The 

source of specific gravity information for each species can be found by 

linking the REF_SPECIES table to the REF_CITATION table. Appendix J 

contains equations used to estimate biomass components in the FIADB. 

116. DRYBIO_TOP Dry biomass in the top of the tree. The oven-dry biomass (pounds) in the top 

and branches (combined) of timber species [trees where diameter is measured 

at breast height (DBH)] ≥5 inches in diameter. DRYBIO_TOP includes the 

tip, the portion of the stem above the merchantable bole (i.e., above the 

4-inch top diameter), and all branches; excludes foliage. Estimated for live 

and dead trees. This is a per tree value and must be multiplied by 

TPA_UNADJ to obtain per acre information. For dead or cut trees, this 

number represents the biomass at the time of death or last measurement. This 

attribute is blank (null) for timber species with DIA <5.0 inches and for 

woodland species. See DRYBIO_WDLD_SPP for biomass of woodland 

species, and DRYBIO_SAPLING for biomass of timber species with DIA 

<5.0 inches. Appendix J contains equations used to estimate biomass 

components in the FIADB. 

117. DRYBIO_STUMP 

 Dry biomass in the tree stump. The oven-dry biomass (pounds) in the stump 

of timber species [trees where diameter is measured at breast height (DBH)] 

≥5 inches in diameter. The stump is that portion of the tree from the ground 

to the bottom of the merchantable bole (i.e., below 1 foot). This is a per tree 

value and must be multiplied by TPA_UNADJ to obtain per acre 

information. Estimated for live and dead trees. For dead or cut trees, this 

number represents the biomass at the time of death or last measurement. This 

attribute is blank (null) for timber species with DIA <5.0 inches and for 

woodland species. See DRYBIO_WDLD_SPP for biomass of woodland 

species, and DRYBIO_SAPLING for biomass of timber species with 
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114 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

DIA <5.0 inches. Appendix J contains equations used to estimate biomass 

components in the FIADB. 

118. DRYBIO_SAPLING 

 Dry biomass of saplings. The oven-dry biomass (pounds) of the aboveground 

portion, excluding foliage, of live trees with a diameter from 1 to 4.9 inches. 

Calculated for timber species only. The biomass of saplings is based on 

biomass computed from Jenkins and others (2003), using the observed 

diameter and an adjustment factor. This is a per tree value and must be 

multiplied by TPA_UNADJ to obtain per acre information. Appendix J 

contains equations used to estimate biomass components in the FIADB. 

119. DRYBIO_WDLD_SPP 

 Dry biomass of woodland tree species. The oven-dry biomass (pounds) of the 

aboveground portion of a live or dead tree, excluding foliage, the tree tip (top 

of the tree above 11⁄2 inches in diameter), and a portion of the stump from 

ground to diameter at root collar (DRC). Calculated for woodland species 

(trees where diameter is measured at DRC) with a diameter ≥1 inch. This is a 

per tree value and must be multiplied by TPA_UNADJ to obtain per acre 

information. This attribute is blank (null) for woodland species with DIA 

<1.0 inch and for all timber species. Appendix J contains equations used to 

estimate biomass components in the FIADB. 

120. DRYBIO_BG Dry biomass of the roots. The oven-dry biomass (pounds) of the 

belowground portion of a tree, includes coarse roots with a root diameter 

≥0.1 inch. This is a modeled estimate, calculated on live trees with a diameter 

of ≥1 inch and dead trees with a diameter of ≥5 inches, for both timber and 

woodland. This is a per tree value and must be multiplied by TPA_UNADJ to 

obtain per acre information. Appendix J contains equations used to estimate 

biomass components in the FIADB. 

121. CARBON_AG Carbon in the aboveground portion of the tree. The carbon (pounds) in the 

aboveground portion, excluding foliage, of live trees with a diameter ≥1 inch, 

and dead trees with a diameter ≥5 inches. Calculated for both timber and 

woodland species. This is a per tree value and must be multiplied by 

TPA_UNADJ to obtain per acre information. Carbon is assumed to be onehalf the value of biomass and is derived by summing the aboveground 

biomass estimates and multiplying by 0.5 as follows: 

 CARBON_AG = 0.5 * (DRYBIO_BOLE + DRYBIO_STUMP + 

DRYBIO_TOP + DRYBIO_SAPLING + DRYBIO_WDLD_SPP) 

122. CARBON_BG Carbon in the belowground portion of the tree. The carbon (pounds) of coarse 

roots >0.1 inch in root diameter. Calculated for live trees with a diameter 

≥1 inch, and dead trees with a diameter ≥5 inches, for both timber and 

woodland species. This is a per tree value and must be multiplied by 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 115

TPA_UNADJ to obtain per acre information. Carbon is assumed to be onehalf the value of belowground biomass as follows: 

 CARBON_BG = 0.5 * DRYBIO_BG 

123. CYCLE Inventory cycle number. A number assigned to a set of plots, measured over 

a particular period of time from which a State estimate using all possible 

plots is obtained. A cycle number >1 does not necessarily mean that 

information for previous cycles resides in the database. A cycle is relevant 

for periodic and annual inventories. 

124. SUBCYCLE Inventory subcycle number. For an annual inventory that takes n years to 

measure all plots, subcycle shows in which of the n years of the cycle the 

data were measured. Subcycle is 0 for a periodic inventory. Subcycle 99 may 

be used for plots that are not included in the estimation process. 

125. BORED_CD_PNWRS 

 Tree bored code, Pacific Northwest Research Station. Used in conjunction 

with tree age (BHAGE and TOTAGE). Only collected by certain FIA work 

units (SURVEY.RSCD = 26). 

Code Description 

1 Trees bored or ‘whorl counted’ at the current inventory 

2 Tree age derived from a previous inventory 

3 Tree age was extrapolated 

126. DAMLOC1_PNWRS 

 Damage location 1, Pacific Northwest Research Station. The location on the 

tree where Damage Agent 1 is found. Only collected by certain FIA work 

units (SURVEY.RSCD = 26). 

Code Location Definition 

0 No damage found. 

1 Roots Above ground up to 12 inches on bole. 

2 Bole Main stem(s) starting at 12 inches above the ground, including 

forks up to a 4 inch top. (A fork is at least equal to 1/3 diameter 

of the bole, and occurs at an angle <45 degrees in relation to 

the bole.) This is not a valid location code for woodland 

species; use only locations 1, 3, and 4. 

3 Branch All other woody material. Primary branch(s) occur at an angle 

≥45° in relation to the bole. 

4 Foliage All leaves, buds, and shoots. 

127. DAMLOC2_PNWRS 

 Damage location 2, Pacific Northwest Research Station. See 

DAMLOC1_PNWRS. Only collected by certain FIA work units 

(SURVEY.RSCD = 26). 
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116 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

128. DIACHECK_PNWRS 

 Diameter check, Pacific Northwest Research Station. A separate estimate of 

the diameter without the obstruction if the diameter was estimated because of 

moss/vine/obstruction, etc. Only collected by certain FIA work units 

(SURVEY.RSCD = 26). 

Code Description 

5 Diameter estimated because of moss. 

6 Diameter estimated because of vines. 

7 Diameter estimated (double nail diameter). 

129. DMG_AGENT1_CD_PNWRS 

 Damage agent 1, Pacific Northwest Research Station. Primary damage agent 

code in PNW. Up to three damaging agents can be coded in PNW as 

DMG_AGENT1_CD_PNWRS, DMG_AGENT2_CD_PNWRS, and 

DMG_AGENT3_CD_PNWRS. A code indicating the tree damaging agent 

that is considered to be of greatest importance to predict tree growth, 

survival, and forest composition and structure. Additionally, there are two 

classes of damaging agents. Class I damage agents are considered more 

important than class II agents and are thus coded as a primary agent before 

the class II agents. For more information, see appendix H. Only collected by 

certain FIA work units (SURVEY.RSCD = 26). 

130. DMG_AGENT2_CD_PNWRS 

 Damage agent 2, Pacific Northwest Research Station. See 

DAM_AGENT1_CD_PNWRS. Only collected by certain FIA work units 

(SURVEY.RSCD = 26). 

131. DMG_AGENT3_CD_PNWRS 

 Damage agent 3, Pacific Northwest Research Station. Damage Agent is a 2-

digit code with values 01 to 91. Only collected by certain FIA work units 

(SURVEY.RSCD = 26). 

132. MIST_CL_CD_PNWRS 

 Leafy mistletoe class code, Pacific Northwest Research Station. All juniper 

species, incense cedars, white fir (CA only) and oak trees are rated for leafy 

mistletoe infection. This item is used to describe the extent and severity of 

leafy mistletoe infection (see MIST_CL_CD for dwarf mistletoe 

information). Only collected by certain FIA work units (SURVEY.RSCD = 26). 

Code Description 

 0 None 

 7 <50 percent of crown infected 

 8 ≥50 percent of crown infected or any occurrence on the bole 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 117

133. SEVERITY1_CD_PNWRS 

 Damage severity 1, Pacific Northwest Research Station for years 2001-2004. 

Damage severity depends on the damage agent coded (see appendix H for 

codes). This is a 2-digit code that indicates either percent of location 

damaged (01-99), or the appropriate class of damage (values vary from 0-9 

depending on the specific Damage Agent). Only collected by certain FIA 

work units (SURVEY.RSCD = 26). 

134. SEVERITY1A_CD_PNWRS 

 Damage severity 1A, Pacific Northwest Research Station. Damage severity 

depends on the damage agent coded (see appendix H for codes). This is a 

2-digit code indicating either percent of location damaged (01-99), or the 

appropriate class of damage (values vary from 0-4 depending on the specific 

Damage Agent). Only collected by certain FIA work units (SURVEY.RSCD 

= 26). 

135. SEVERITY1B_CD_PNWRS 

 Damage severity 1B, Pacific Northwest Research Station. Damage severity B 

is only coded when the Damage Agent is white pine blister rust (36). Only 

collected by certain FIA work units (SURVEY.RSCD = 26). 

Code Description 

1 Branch infections located more than 2.0 feet from tree bole. 

2 Branch infections located 0.5 to 2.0 feet from tree bole. 

3 Branch infection located within 0.5 feet of tree bole OR tree bole infection 

present. 

136. SEVERITY2_CD_PNWRS 

 Damage severity 2, Pacific Northwest Research Station for years 2001-2004. 

Damage severity depends on the damage agent coded (see appendix H for 

codes). This is a 2-digit code indicating either percent of location damaged 

(01-99), or the appropriate class of damage (values vary from 0-9 depending 

on the specific Damage Agent). Only collected by certain FIA work units 

(SURVEY.RSCD = 26). 

137. SEVERITY2A_CD_PNWRS 

 Damage severity 2A, Pacific Northwest Research Station starting in 2005. 

See SEVERITY1A_CD_PNWRS. Only collected by certain FIA work units 

(SURVEY.RSCD = 26). 

138. SEVERITY2B_CD_PNWRS 

 Damage severity 2B, Pacific Northwest Research Station starting in 2005. 

See SEVERITY1B_CD_PNWRS. Only collected by certain FIA work units 

(SURVEY.RSCD = 26). 
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118 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

139. SEVERITY3_CD_PNWRS 

 Damage severity 3, Pacific Northwest Research Station for years 2001-2004. 

Damage severity depends on the damage agent coded (see appendix H for 

codes). This is a 2-digit code indicating either percent of location damaged 

(01-99), or the appropriate class of damage (values vary from 0-9 depending 

on the specific Damage Agent). Only collected by certain FIA work units 

(SURVEY.RSCD = 26). 

140. UNKNOWN_DAMTYP1_PNWRS 

 Unknown damage type 1, Pacific Northwest Research Station. A code 

indicating the sign or symptom recorded when UNKNOWN damage code 90 

is used. Only collected by certain FIA work units (SURVEY.RSCD = 26). 

Code Description 

1 canker/gall 

2 open wound 

3 resinosis 

4 broken 

5 damaged or discolored foliage 

6 other 

141. UNKNOWN_DAMTYP2_PNWRS 

 Unknown damage type 2, Pacific Northwest Research Station. See 

UNKNOWN_DAMTYP1_PNWRS. Only collected by certain FIA work 

units (SURVEY.RSCD = 26). 

142. PREV_PNTN_SRS 

 Previous periodic prism number, tree number, Southern Research Station. In 

some older Southeast Experiment Station states, the prism point, tree number 

(PNTN) of the current cycle did not match the previous cycle's prism point, 

tree number. PREV_PNTN_SRS is used to join the current and the previous 

prism plot trees. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 119

Seedling Table (Oracle table name is SEEDLING) 

 Column name Descriptive name Oracle data type 

1 CN Sequence number VARCHAR2(34) 

2 PLT_CN Plot sequence number VARCHAR2(34) 

3 INVYR Inventory year NUMBER(4) 

4 STATECD State code NUMBER(4) 

5 UNITCD Unit code NUMBER(2) 

6 COUNTYCD County code NUMBER(3) 

7 PLOT Phase 2 plot number NUMBER(5) 

8 SUBP Subplot number NUMBER(3) 

9 CONDID Condition class number NUMBER(1) 

10 SPCD Species code NUMBER 

11 SPGRPCD Species group code NUMBER(2) 

12 STOCKING Tree stocking NUMBER(7,4) 

13 TREECOUNT Tree count for seedlings NUMBER(3) 

14 TOTAGE Total age NUMBER(3) 

15 CREATED_BY Created by VARCHAR2(30) 

16 CREATED_DATE Created date DATE 

17 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

18 MODIFIED_BY Modified by VARCHAR2(30) 

19 MODIFIED_DATE Modified date DATE 

20 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

21 TREECOUNT_CALC Tree count used in calculations NUMBER 

22 TPA_UNADJ Trees per acre unadjusted NUMBER(11,6) 

23 CYCLE Inventory cycle number NUMBER(2) 

24 SUBCYCLE Inventory subcycle number NUMBER(2) 

Type of key Column(s) Tables to link Abbreviated notation 

Primary (CN) N/A SDL_PK 

Unique (PLT_CN, SUBP, CONDID, SPCD) N/A SDL_UK 

Natural (STATECD, INVYR, UNITCD, 

COUNTYCD, PLOT, SUBP, 

CONDID, SPCD) 

N/A SDL_NAT_I 

Foreign (PLT_CN) SEEDLING to PLOT SDL_PLT_FK 

Seedling data collection overview – When PLOT.MANUAL <2.0, the national core procedure was 

to record the actual seedling count up to six seedlings and then record 6+ if at least six seedlings 

were present. However, the following regions collected the actual seedling count when 

PLOT.MANUAL <2.0: Rocky Mountain Research Station (RMRS) and North Central Research 

Station (NCRS). If PLOT.MANUAL <2.0 and TREECOUNT is blank (null), then a value of 6 in 

TREECOUNT_CALC represents 6 or more seedlings. In the past, seedlings were often tallied in 

FIA inventories only to the extent necessary to determine if some minimum number were present, 
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Chapter 3. Seedling Table 

120 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

which means that seedlings were often under-reported. Note: The SEEDLING record may not exist 

for some periodic inventories. 

 1. CN Sequence number. A unique index used to easily identify a seedling. 

 2. PLT_CN Plot sequence number. Foreign key linking the seedling record to the plot 

record. 

 3. INVYR Inventory year. The year that best represents when the inventory data were 

collected. Under the annual inventory system, a group of plots is selected 

each year for sampling. The selection is based on a panel system. INVYR is 

the year in which the majority of plots in that group were collected (plots in 

the group have the same panel and, if applicable, subpanel). Under periodic 

inventory, a reporting inventory year was selected, usually based on the year 

in which the majority of the plots were collected or the mid-point of the years 

over which the inventory spanned. For either annual or periodic inventory, 

INVYR is not necessarily the same as MEASYEAR. 

 Exceptions: 

 INVYR = 9999. INVYR is set to 9999 to distinguish Phase 3 plots taken by 

the western FIA work units that are “off subpanel.” This is due to differences 

in measurement intervals between Phase 3 (measurement interval = 5 years) 

and Phase 2 (measurement interval = 10 years) plots. Only users interested in 

performing certain Phase 3 data analyses should access plots with this 

anomalous value in INVYR. 

 INVYR <100. INVYR <100 indicates that population estimates were derived 

from a pre-NIMS regional processing system and the same plot either has 

been or may soon be re-processed in NIMS as part of a separate evaluation. 

The NIMS processed copy of the plot follows the standard INVYR format. 

This only applies to plots collected in the South (SURVEY.RSCD = 33) with 

the national design or a similar regional design (PLOT.DESIGNCD = 1 or 

220-233) that were collected when the inventory year was 1998 through 

2005. 

 INVYR = 98 is equivalent to 1998 but processed through regional system 

 INVYR = 99 is equivalent to 1999 but processed through regional system 

 INVYR = 0 is equivalent to 2000 but processed through regional system 

 INVYR = 1 is equivalent to 2001 but processed through regional system 

 INVYR = 2 is equivalent to 2002 but processed through regional system 

 INVYR = 3 is equivalent to 2003 but processed through regional system 

 INVYR = 4 is equivalent to 2004 but processed through regional system 

 INVYR = 5 is equivalent to 2005 but processed through regional system 

 4. STATECD State code. Bureau of the Census Federal Information Processing Standards 

(FIPS) two-digit code for each State. Refer to appendix C. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 121

 5. UNITCD Survey unit number. Forest Inventory and Analysis survey unit identification 

number. Survey units are usually groups of counties within each State. For 

periodic inventories, Survey units may be made up of lands of particular 

owners. Refer to appendix C for codes. 

 6. COUNTYCD County code. The identification number for a county, parish, watershed, 

borough, or similar governmental unit in a State. FIPS codes from the Bureau 

of the Census are used. Refer to appendix C for codes. 

 7. PLOT Phase 2 plot number. An identifier for a plot. Along with STATECD, 

INVYR, UNITCD, COUNTYCD and/or some other combinations of 

variables, PLOT may be used to uniquely identify a plot. 

 8. SUBP Subplot number. The number assigned to the subplot. The national plot 

design (PLOT.DESIGNCD = 1) has subplot number values of 1 through 4. 

Other plot designs have various subplot number values. See 

PLOT.DESIGNCD and appendix B for information about plot designs. For 

more explanation about SUBP, contact the appropriate FIA work unit (table 

6). 

 9. CONDID Condition class number. Unique identifying number assigned to each 

condition on a plot. A condition is initially defined by condition class status. 

Differences in reserved status, owner group, forest type, stand-size class, 

regeneration status, and stand density further define condition for forest land. 

Mapped nonforest conditions are also assigned numbers. At the time of the 

plot establishment, the condition class at plot center (the center of subplot 1) 

is usually designated as condition class 1. Other condition classes are 

assigned numbers sequentially at the time each condition class is delineated. 

On a plot, each sampled condition class must have a unique number that can 

change at remeasurement to reflect new conditions on the plot. 

 10. SPCD Species code. An FIA species code. Refer to appendix F for codes. 

 11. SPGRPCD Species group code. A code assigned to each tree species in order to group 

them for reporting purposes on presentation tables. Codes and their 

associated names (see REF_SPECIES_GROUP.NAME) are shown in 

appendix G. Individual tree species and corresponding species group codes 

are shown in appendix F. 

 12. STOCKING Tree stocking. The stocking value assigned to each count of seedlings, by 

species. Stocking is a relative term used to describe (in percent) the adequacy 

of a given stand density in meeting a specific management objective. Species 

or forest type stocking functions were used to assess the stocking 

contribution of seedling records. These functions, which were developed 

using stocking guides, relate the area occupied by an individual tree to the 

area occupied by a tree of the same size growing in a fully stocked stand of 

like trees. The stocking of seedling count records is used in the calculation of 

COND.GSSTKCD and COND.ALSTKCD on the condition record. 
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122 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 13. TREECOUNT Tree count (for seedlings). Indicates the number of seedlings (DIA <1.0 inch) 

present on the microplot. Conifer seedlings are at least 6 inches tall and 

hardwood seedlings are at least 12 inches tall. When PLOT.MANUAL <2.0, 

the national core procedure was to record the actual seedling count up to six 

seedlings and then record 6+ if at least six seedlings were present. However, 

the following regions collected the actual seedling count when 

PLOT.MANUAL <2.0: Rocky Mountain Research Station (RMRS) and 

North Central Research Station (NCRS). If PLOT.MANUAL <2.0 and 

TREECOUNT is blank (null), then a value of 6 in TREECOUNT_CALC 

represents 6 or more seedlings. 

 14. TOTAGE Total age. The seedling’s total age. Total age is collected for a subset of 

seedling count records, using one representative seedling for the species. The 

age is obtained by counting the terminal bud scars or the whorls of branches 

and may be used in the stand age calculation. Only collected by certain FIA 

work units (SURVEY.RSCD = 22). This attribute may be blank (null) for 

SURVEY.RSCD = 22 and is always null for the other FIA work units. 

 15. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 16. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 17. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 18. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 19. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 20. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 123

 21. TREECOUNT_CALC 

 Tree count used in calculations. This attribute is set either to COUNTCD, 

which was dropped in FIADB version 2.1, or TREECOUNT. When 

PLOT.MANUAL <2.0, the national core procedure was to record the actual 

seedling count up to six seedlings and then record 6+ if at least six seedlings 

were present. However, the following regions collected the actual seedling 

count when PLOT.MANUAL <2.0: Rocky Mountain Research Station 

(RMRS) and North Central Research Station (NCRS). If 

PLOT.MANUAL <2.0 and TREECOUNT is blank (null), then a value of 6 in 

TREECOUNT_CALC represents 6 or more seedlings. 

 22. TPA_UNADJ Trees per acre unadjusted. The number of seedlings per acre that the seedling 

count theoretically represents based on the sample design. For fixed radius 

plots taken with the mapped plot design (PLOT.DESIGNCD =1), 

TPA_UNADJ equals 74.965282 times the number of seedlings counted. For 

plots taken with other sample designs, this attribute may be blank (null). 

Based on the procedures described in Bechtold and Patterson (2005), this 

attribute can be adjusted using factors stored on the POP_STRATUM table to 

derive population estimates. Examples of estimating population totals are 

shown in chapter 4. 

 23. CYCLE Inventory cycle number. A number assigned to a set of plots, measured over 

a particular period of time from which a State estimate using all possible 

plots is obtained. A cycle number >1 does not necessarily mean that 

information for previous cycles resides in the database. A cycle is relevant 

for periodic and annual inventories. 

 24. SUBCYCLE Inventory subcycle number. For an annual inventory that takes n years to 

measure all plots, subcycle shows in which of the n years of the cycle the 

data were measured. Subcycle is 0 for a periodic inventory. Subcycle 99 may 

be used for plots that are not included in the estimation process. 
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Chapter 3. Site Tree Table 

124 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Site Tree Table (Oracle table name is SITETREE) 

 Column name Descriptive name Oracle data type 

1 CN Sequence number VARCHAR2(34) 

2 PLT_CN Plot sequence number VARCHAR2(34) 

3 PREV_SIT_CN Previous site tree sequence number VARCHAR2(34) 

4 INVYR Inventory year NUMBER(4) 

5 STATECD State code NUMBER(4) 

6 UNITCD Survey unit code NUMBER(2) 

7 COUNTYCD County code NUMBER(3) 

8 PLOT Phase 2 plot number NUMBER(5) 

9 CONDID Condition class number NUMBER(1) 

10 TREE Tree number NUMBER(9) 

11 SPCD Species code NUMBER 

12 DIA Diameter NUMBER(5,2) 

13 HT Total height NUMBER(3) 

14 AGEDIA Tree age at diameter NUMBER(3) 

15 SPGRPCD Species group code NUMBER(2) 

16 SITREE Site index for the tree NUMBER(3) 

17 SIBASE Site index base age NUMBER(3) 

18 SUBP Subplot number NUMBER(3) 

19 AZIMUTH Azimuth NUMBER(3) 

20 DIST Horizontal distance NUMBER(4,1) 

21 METHOD Site tree method code NUMBER(2) 

22 SITREE_EST Estimated site index for the tree NUMBER(3) 

23 VALIDCD Validity code NUMBER(1) 

24 CONDLIST Condition class list NUMBER(4) 

25 CREATED_BY Created by VARCHAR2(30) 

26 CREATED_DATE Created date DATE 

27 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

28 MODIFIED_BY Modified by VARCHAR2(30) 

29 MODIFIED_DATE Modified date DATE 

30 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

31 CYCLE Inventory cycle number NUMBER(2) 

32 SUBCYCLE Inventory subcycle number NUMBER(2) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (CN) N/A SIT_PK 

Unique (PLT_CN, CONDID, TREE) N/A SIT_UK 

Natural (STATECD, INVYR, 

UNITCD, COUNTYCD, 

PLOT, CONDID, TREE) 

N/A SIT_NAT_I 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 125

Type of key Column(s) order Tables to link Abbreviated notation 

Foreign (PLT_CN, CONDID) SITETREE to COND SIT_CND_FK 

(PLT_CN) SITETREE to PLOT SIT_PLT_FK 

Note: The SITETREE record may not exist for some periodic inventory data. 

 

 1. CN Sequence number. A unique sequence number used to identify a site tree 

record. 

 2. PLT_CN Plot sequence number. Foreign key linking the site tree record to the plot 

record. 

 3. PREV_SIT_CN Previous site tree sequence number. Foreign key linking the site tree to the 

previous inventory’s site tree record for this tree. Only populated for site trees 

from previous annual inventories. 

 4. INVYR Inventory year. The year that best represents when the inventory data were 

collected. Under the annual inventory system, a group of plots is selected 

each year for sampling. The selection is based on a panel system. INVYR is 

the year in which the majority of plots in that group were collected (plots in 

the group have the same panel and, if applicable, subpanel). Under periodic 

inventory, a reporting inventory year was selected, usually based on the year 

in which the majority of the plots were collected or the mid-point of the years 

over which the inventory spanned. For either annual or periodic inventory, 

INVYR is not necessarily the same as MEASYEAR. 

 Exceptions: 

 INVYR = 9999. INVYR is set to 9999 to distinguish Phase 3 plots taken by 

the western FIA work units that are “off subpanel.” This is due to differences 

in measurement intervals between Phase 3 (measurement interval = 5 years) 

and Phase 2 (measurement interval = 10 years) plots. Only users interested in 

performing certain Phase 3 data analyses should access plots with this 

anomalous value in INVYR. 

 INVYR <100. INVYR <100 indicates that population estimates were derived 

from a pre-NIMS regional processing system and the same plot either has 

been or may soon be re-processed in NIMS as part of a separate evaluation. 

The NIMS processed copy of the plot follows the standard INVYR format. 

This only applies to plots collected in the South (SURVEY.RSCD = 33) with 

the national design or a similar regional design (PLOT.DESIGNCD = 1 or 

220-233) that were collected when the inventory year was 1998 through 

2005. 

 INVYR = 98 is equivalent to 1998 but processed through regional system 

 INVYR = 99 is equivalent to 1999 but processed through regional system 

 INVYR = 0 is equivalent to 2000 but processed through regional system 

 INVYR = 1 is equivalent to 2001 but processed through regional system 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Site Tree Table 

126 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 INVYR = 2 is equivalent to 2002 but processed through regional system 

 INVYR = 3 is equivalent to 2003 but processed through regional system 

 INVYR = 4 is equivalent to 2004 but processed through regional system 

 INVYR = 5 is equivalent to 2005 but processed through regional system 

 5. STATECD State code. Bureau of the Census Federal Information Processing Standards 

(FIPS) two-digit code for each State. Refer to appendix C. 

 6. UNITCD Survey unit code. Forest Inventory and Analysis survey unit identification 

number. Survey units are usually groups of counties within each State. For 

periodic inventories, survey units may be made up of lands of particular 

owners. Refer to appendix C for codes. 

 7. COUNTYCD County code. The identification number for a county, parish, watershed, 

borough, or similar governmental unit in a State. FIPS codes from the Bureau 

of the Census are used. Refer to appendix C for codes. 

 8. PLOT Phase 2 plot number. An identifier for a plot. Along with STATECD, 

INVYR, UNITCD, COUNTYCD and/or some other combinations of 

variables, PLOT may be used to uniquely identify a plot. 

 9. CONDID Condition class number. Unique identifying number assigned to each 

condition on a plot. A condition is initially defined by condition class status. 

Differences in reserved status, owner group, forest type, stand-size class, 

regeneration status, and stand density further define condition for forest land. 

Mapped nonforest conditions are also assigned numbers. At the time of the 

plot establishment, the condition class at plot center (the center of subplot 1) 

is usually designated as condition class 1. Other condition classes are 

assigned numbers sequentially at the time each condition class is delineated. 

On a plot, each sampled condition class must have a unique number that can 

change at remeasurement to reflect new conditions on the plot. 

 10. TREE Tree number. A number used to uniquely identify a site tree on a condition. 

 11. SPCD Species code. A standard tree species code. Refer to appendix F for codes. 

 12. DIA Diameter. The current diameter (in inches) of the tree at the point of diameter 

measurement (DBH/DRC). 

 13. HT Total height. The total length (height) of a sample tree (in feet) from the 

ground to the top of the main stem. 

 14. AGEDIA Tree age at diameter. Age (in years) of tree at the point of diameter 

measurement (DBH/DRC). Age is determined by an increment sample. 

 15. SPGRPCD Species group code. A code assigned to each tree species in order to group 

them for reporting purposes on presentation tables. Codes and their 

associated names (see REF_SPECIES_GROUP.NAME) are shown in 

appendix G. Individual tree species and corresponding species group codes 

are shown in appendix F. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 127

 16. SITREE Site index for the tree. Site index is calculated for dominant and co-dominant 

trees using one of several methods (see METHOD). It is expressed as height 

in feet that the tree is expected to attain at a base- or reference age (see 

SIBASE). Most commonly, site index is calculated using a family of curves 

that show site index as a function of total length and either breast-height age 

or total age. The height-intercept (or growth-intercept) method is commonly 

used for young trees or species that produce conspicuous annual branch 

whorls; using this method, site index is calculated with the height growth 

attained for a short period (usually 3 to 5 years) after the tree has reached 

breast height. Neither age nor total length determination are necessary when 

using the height-intercept method, so one or more of those variables may be 

null for a site tree on which the height-intercept method was used. 

 17. SIBASE Site index base age. The base age (sometimes called reference age), in years, 

of the site index curves used to derive site index. Base age is specific to a 

given family of site index curves, and is usually set close to the common 

rotation age or the age of culmination of mean annual increment for a 

species. The most commonly used base ages are 25, 50, 80, and 100 years. It 

is possible for a given species to have different sets of site index curves in 

different geographic regions, and each set of curves may use a different base 

age. 

 18. SUBP Subplot number. (Core optional.) The number assigned to the subplot. The 

national plot design (PLOT.DESIGNCD = 1) has subplot number values of 1 

through 4. Other plot designs have various subplot number values. See 

PLOT.DESIGNCD and appendix B for information about plot designs. For 

more explanation about SUBP, contact the appropriate FIA work unit (table 

6). 

 19. AZIMUTH Azimuth. (Core optional.) The direction, to the nearest degree, from subplot 

center to the center of the base of the tree (geographic center for multistemmed woodland species). Due north is represented by 360 degrees. 

 20. DIST Horizontal distance. (Core optional.) The horizontal distance in feet from 

subplot center (microplot center for saplings) to the pith at the base of the 

tree (geographic center for multi-stemmed woodland species). 

 21. METHOD Site tree method code. The method for determining the site index. 

Code Description 

1 Tree measurements (length, age, etc.) collected during this inventory. 

2 Tree measurements (length, age, etc.) collected during a previous inventory. 

3 Site index estimated either in the field or office. 

4 Site index determined by the height intercept method during this inventory. 

 22. SITREE_EST Estimated site index for the tree. The estimated site index or the site index 

determined by the height intercept method. 

 23. VALIDCD Validity code. A code indicating if this site tree provided a valid result from 

the site index computation. Some trees collected by the field crew yield a 
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Chapter 3. Site Tree Table 

128 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

negative value from the equation due to their age, height or diameter being 

outside the range of values for which the equation was developed. 

Computational results for trees that fail are not used to estimate the site index 

or site productivity class for the condition. If the site calculation for this tree 

was successful, this attribute is set to 1. 

Code Description 

0 Tree failed in site index calculations. 

1 Tree was successful in site index calculations. 

 24. CONDLIST Condition class list. A list of numbers indicating all of the condition classes 

for which the site index data for this tree can be used. 

 25. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 26. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 27. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 28. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 29. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 30. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 

 31. CYCLE Inventory cycle number. A number assigned to a set of plots, measured over 

a particular period of time from which a State estimate using all possible 

plots is obtained. A cycle number >1 does not necessarily mean that 
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Chapter 3. Site Tree Table 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 129

information for previous cycles resides in the database. A cycle is relevant 

for periodic and annual inventories. 

 32. SUBCYCLE Inventory subcycle number. For an annual inventory that takes n years to 

measure all plots, subcycle shows in which of the n years of the cycle the 

data were measured. Subcycle is 0 for a periodic inventory. Subcycle 99 may 

be used for plots that are not included in the estimation process. 
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Chapter 3. Boundary Table 

130 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Boundary Table (Oracle table name is BOUNDARY) 

 Column name Descriptive name Oracle data type 

1 CN Sequence number VARCHAR2(34) 

2 PLT_CN Plot sequence number VARCHAR2(34) 

3 INVYR Inventory year NUMBER(4) 

4 STATECD State code NUMBER(4) 

5 UNITCD Survey unit code NUMBER(2) 

6 COUNTYCD County code NUMBER(3) 

7 PLOT Phase 2 plot number NUMBER(5) 

8 SUBP Subplot number NUMBER(3) 

9 SUBPTYP Plot type code NUMBER(1) 

10 BNDCHG Boundary change code NUMBER(1) 

11 CONTRAST Contrasting condition NUMBER(1) 

12 AZMLEFT Left azimuth NUMBER(3) 

13 AZMCORN Corner azimuth NUMBER(3) 

14 DISTCORN Corner distance NUMBER(3) 

15 AZMRIGHT Right azimuth NUMBER(3) 

16 CYCLE Inventory cycle number NUMBER(2) 

17 SUBCYCLE Inventory subcycle number NUMBER(2) 

18 CREATED_BY Created by VARCHAR2(30) 

19 CREATED_DATE Created date DATE 

20 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

21 MODIFIED_BY Modified by VARCHAR2(30) 

22 MODIFIED_DATE Modified date DATE 

23 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (CN) N/A BND_PK 

Unique (PLT_CN, SUBP, 

SUBPTYP, AZMLEFT, 

AZMRIGHT) 

N/A BND_UK 

Natural (STATECD, INVYR, 

UNITCD, COUNTYCD, 

PLOT, SUBP, SUBPTYP, 

AZMLEFT, AZMRIGHT) 

N/A BND_NAT_I 

Foreign (PLT_CN) BOUNDARY to PLOT BND_PLT_FK 

Note: The BOUNDARY record may not exist for some periodic inventory data. 

 1. CN Sequence number. A unique sequence number used to identify a boundary 

record. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 131

 2. PLT_CN Plot sequence number. Foreign key linking the boundary record to the plot 

record. 

 3. INVYR Inventory year. The year that best represents when the inventory data were 

collected. Under the annual inventory system, a group of plots is selected 

each year for sampling. The selection is based on a panel system. INVYR is 

the year in which the majority of plots in that group were collected (plots in 

the group have the same panel and, if applicable, subpanel). Under periodic 

inventory, a reporting inventory year was selected, usually based on the year 

in which the majority of the plots were collected or the mid-point of the years 

over which the inventory spanned. For either annual or periodic inventory, 

INVYR is not necessarily the same as MEASYEAR. 

 Exceptions: 

 INVYR = 9999. INVYR is set to 9999 to distinguish Phase 3 plots taken by 

the western FIA work units that are “off subpanel.” This is due to differences 

in measurement intervals between Phase 3 (measurement interval = 5 years) 

and Phase 2 (measurement interval = 10 years) plots. Only users interested in 

performing certain Phase 3 data analyses should access plots with this 

anomalous value in INVYR. 

 INVYR <100. INVYR <100 indicates that population estimates were derived 

from a pre-NIMS regional processing system and the same plot either has 

been or may soon be re-processed in NIMS as part of a separate evaluation. 

The NIMS processed copy of the plot follows the standard INVYR format. 

This only applies to plots collected in the South (SURVEY.RSCD = 33) with 

the national design or a similar regional design (PLOT.DESIGNCD = 1 or 

220-233) that were collected when the inventory year was 1998 through 

2005. 

 INVYR = 98 is equivalent to 1998 but processed through regional system 

 INVYR = 99 is equivalent to 1999 but processed through regional system 

 INVYR = 0 is equivalent to 2000 but processed through regional system 

 INVYR = 1 is equivalent to 2001 but processed through regional system 

 INVYR = 2 is equivalent to 2002 but processed through regional system 

 INVYR = 3 is equivalent to 2003 but processed through regional system 

 INVYR = 4 is equivalent to 2004 but processed through regional system 

 INVYR = 5 is equivalent to 2005 but processed through regional system 

 4. STATECD State code. Bureau of the Census Federal Information Processing Standards 

(FIPS) two-digit code for each State. Refer to appendix C. 

 5. UNITCD Survey unit code. Forest Inventory and Analysis survey unit identification 

number. Survey units are usually groups of counties within each State. For 

periodic inventories, survey units may be made up of lands of particular 

owners. Refer to appendix C for codes. 
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132 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 6. COUNTYCD County code. The identification number for a county, parish, watershed, 

borough, or similar governmental unit in a State. FIPS codes from the Bureau 

of the Census are used. Refer to appendix C for codes. 

 7. PLOT Phase 2 plot number. An identifier for a plot. Along with STATECD, 

UNITCD, INVYR, COUNTYCD and/or some other combinations of 

variables, PLOT may be used to uniquely identify a plot. 

 8. SUBP Subplot number. The number assigned to the subplot. The national plot 

design (PLOT.DESIGNCD = 1) has subplot number values of 1 through 4. 

Other plot designs have various subplot number values. See 

PLOT.DESIGNCD and appendix B for information about plot designs. For 

more explanation about SUBP, contact the appropriate FIA work unit. 

 9. SUBPTYP Plot type code. Specifies whether the boundary data are for a subplot, 

microplot, or macroplot. 

Code Description 

1 Subplot boundary 

2 Microplot boundary 

3 Macroplot boundary 

 10. BNDCHG Boundary change code. A code indicating the relationship between 

previously recorded and current boundary information. Set to blank (null) for 

new plots (PLOT.KINDCD = 1 or 3). 

Code Description 

0 No change – boundary is the same as indicated on plot map by previous crew. 

1 New boundary, or boundary data have been changed to reflect an actual on-theground physical change resulting in a difference from the boundaries recorded. 

2 Boundary has been changed to correct an error from a previous crew. 

3 Boundary has been changed to reflect a change in variable definition. 

 11. CONTRAST Contrasting condition. The condition class number of the condition class that 

contrasts with the condition class located at the subplot center (for boundaries 

on the subplot or macroplot) or at the microplot center (for boundaries on the 

microplot), e.g., the condition class present on the other side of the boundary. 

 12. AZMLEFT Left azimuth. The azimuth, to the nearest degree, from the subplot, microplot, 

or macroplot plot center to the farthest left point (facing the contrasting 

condition class) where the boundary intersects the subplot, microplot, or 

macroplot plot circumference. 

 13. AZMCORN Corner azimuth. The azimuth, to the nearest degree, from the subplot, 

microplot, or macroplot plot center to a corner or curve in a boundary. If a 

boundary is best described by a straight line between the two circumference 

points, then 000 is recorded for AZMCORN. 

 14. DISTCORN Corner distance. The horizontal distance, to the nearest 1 foot, from the 

subplot, microplot, or macroplot plot center to the boundary corner point. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 133

Blank (null) when AZMCORN = 000; populated when 

BOUNDARY.AZMCORN >000. 

 15. AZMRIGHT Right azimuth. The azimuth, to the nearest degree, from subplot, microplot, 

or macroplot plot center to the farthest right point (facing the contrasting 

condition) where the boundary intersects the subplot, microplot, or macroplot 

plot circumference. 

 16. CYCLE Inventory cycle number. A number assigned to a set of plots, measured over 

a particular period of time from which a State estimate using all possible 

plots is obtained. A cycle number >1 does not necessarily mean that 

information for previous cycles resides in the database. A cycle is relevant 

for periodic and annual inventories. 

 17. SUBCYCLE Inventory subcycle number. For an annual inventory that takes n years to 

measure all plots, subcycle shows in which of the n years of the cycle the 

data were measured. Subcycle is 0 for a periodic inventory. Subcycle 99 may 

be used for plots that are not included in the estimation process. 

 18. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 19. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 20. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 21. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 22. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 
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Chapter 3. Boundary Table 

134 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 23. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Subplot Condition Change Matrix Table 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 135

Subplot Condition Change Matrix (Oracle table name is SUBP_COND_CHNG_MTRX) 

 Column name Descriptive name Oracle data type 

1 CN Sequence number VARCHAR2(34) 

2 STATECD State code NUMBER(4) 

3 SUBP Subplot number NUMBER(1) 

4 SUBPTYP Subplot type NUMBER(1) 

5 PLT_CN Plot sequence number VARCHAR2(34) 

6 CONDID Condition class number NUMBER(1) 

7 PREV_PLT_CN Previous plot sequence number VARCHAR2(34) 

8 PREVCOND Previous condition class number NUMBER(1) 

9 SUBPTYP_PROP_CHNG Percent change of subplot condition 

between previous to current inventory NUMBER(5,4) 

10 CREATED_BY Created by VARCHAR2(30) 

11 CREATED_DATE Created date DATE 

12 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

13 MODIFIED_BY Modified by VARCHAR2(30) 

14 MODIFIED_DATE Modified date DATE 

15 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (CN) N/A CMX_PK 

Unique (PLT_CN, PREV_PLT_CN, 

SUBP, SUBPTYP, 

CONDID, PREVCOND) 

N/A CMX_UK 

Foreign (PREV_PLT_CN) SUBP_COND_CHNG_MTRX 

to PLOT 

CMX_PLT_FK 

 (PLT_CN) SUBP_COND_CHNG_MTRX 

to PLOT 

CMX_PLT_FK2 

This table contains information about the mix of current and previous conditions that occupy the 

same area on the subplot. Figure 5 provides an illustration of how the information in this table is 

derived using data from two points in time that is stored in the BOUNDARY and COND tables. 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Subplot Condition Change Matrix Table 

136 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 1. CN Sequence number. A unique sequence number used to identify a change 

matrix table record. 

 2. STATECD States code. Bureau of the Census Federal Information Processing Standards 

(FIPS) two-digit code for each State. Refer to appendix C. 

 3. SUBP Subplot number. The number assigned to the subplot. The national plot 

design (PLOT.DESIGNCD = 1) has subplot number values of 1 through 4. 

Other plot designs have various subplot number values. 

Figure 5. Illustration of the SUBP_COND_CHNG_MTRX table function 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Subplot Condition Change Matrix Table 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 137

 4. SUBPTYP Plot type code. Specifies whether the record is for a subplot, microplot, or 

macroplot. 

Code Description 

1 Subplot 

2 Microplot 

3 Macroplot 

 5. PLT_CN Plot sequence number. The foreign key linking the 

SUBP_COND_CHNG_MTRX record to the PLOT record for the current 

inventory. 

 6. CONDID Condition class number. Unique identifying number assigned to each 

condition on a plot. 

 7. PREV_PLT_CN 

 Previous plot sequence number. The foreign key linking the 

SUBP_COND_CHNG_MTRX record to the PLOT record from the previous 

inventory. 

 8. PREVCOND Previous condition class number. Identifies the condition class number from 

the previous inventory. 

 9. SUBPTYP_PROP_CHNG 

 Subplot type proportion change. The unadjusted proportion of the subplot 

that is in the same geographic area condition for both the previous and 

current inventory. The sum of all subplot type change proportions for an 

individual plot equals 4 for each plot type (microplot, subplot, and/or 

macroplot). Divide the result by 4 to obtain change at the plot level. 

 10. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 11. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 12. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Subplot Condition Change Matrix Table 

138 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 13. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 14. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 15. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation.
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Chapter 3. Tree Regional Biomass Table 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 139

Tree Regional Biomass Table (Oracle table name is TREE_REGIONAL_BIOMASS) 

 Column name Descriptive name Oracle data type 

1 TRE_CN Tree sequence number VARCHAR2(34) 

2 STATECD State code NUMBER(4) 

3 REGIONAL_DRYBIOT Regional total tree biomass oven-dry 

weight NUMBER(13,6) 

4 REGIONAL_DRYBIOM Regional merchantable stem biomass 

oven-dry weight NUMBER(13,6) 

5 CREATED_BY Created by VARCHAR2(30) 

6 CREATED_DATE Created date DATE 

7 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

8 MODIFIED_BY Modified by VARCHAR2(30) 

9 MODIFIED_DATE Modified date DATE 

10 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (TRE_CN) N/A TRB_PK 

Foreign (TRE_CN) TREE_REGIONAL_BIOMASS to 

TREE 

TRB_TRE_FK 

This table provides biomass estimates of live and dead trees 1 inch in diameter and larger using 

equations and methods that vary by FIA work unit. Both REGIONAL_DRYBIOT and 

REGIONAL_DRYBIOM preserve the original data and computation procedures used by FIA work 

units to calculate DRYBIOT and DRYBIOM in previous versions of FIADB. Users should be 

aware that for some FIA work units, these biomass estimates may not include bark. Biomass 

estimates in this table will differ from biomass estimates found on the TREE table records because 

components such as bark, stump, and top (with branches) are now being stored on the TREE table 

are derived by applying ratios to stem biomass. The TREE table will be the source of biomass data 

used in official reporting. However, the TREE_REGIONAL_BIOMASS table contains valuable 

information for generating biomass estimates that match earlier published reports. 

 1. TRE_CN Tree sequence number. Foreign key linking the tree regional biomass record 

to the tree record. 

 2. STATECD States code. Bureau of the Census Federal Information Processing Standards 

(FIPS) two-digit code for each State. Refer to appendix C. 

 3. REGIONAL_DRYBIOT 

Regional dry total biomass (pounds). The total aboveground biomass of a 

sample tree 1.0 inch diameter or larger, including all tops and limbs (but 

excluding foliage). This is a per tree value and must be multiplied by 

TPA_UNADJ to obtain per acre information. Calculated in oven-dry pounds 

per tree. This field should have an entry if DIA is 1.0 inch or larger, 

regardless of STATUSCD or TREECLCD; zero otherwise. For dead or cut 

trees, this number represents the biomass at the time of death or last 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Tree Regional Biomass Table 

140 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

measurement. Because total biomass has been calculated differently among 

FIA work units, contact the appropriate FIA work units (see table 6) for 

information on how biomass was estimated and whether bark was included. 

 4. REGIONAL_DRYBIOM 

Regional dry merchantable stem biomass (pounds). The total gross biomass 

(including bark) of a tree 5.0 inches DBH or larger from a 1-foot stump to a 

minimum 4-inch top diameter of the central stem. This is a per tree value and 

must be multiplied by TPA_UNADJ to obtain per acre information. 

Calculated in oven-dry pounds per tree. This field should have an entry if 

DIA is 5.0 inches or larger, regardless of STATUSCD or TREECLCD; zero 

otherwise. For dead or cut trees, this number represents the biomass at the 

time of death or last measurement. Because total biomass has been calculated 

differently among FIA work units, contact the appropriate FIA work unit (see 

table 6) for information on how biomass was estimated and whether bark was 

actually included. 

 5. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 6. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 7. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 8. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 9. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 10. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 
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Chapter 3. Population Estimation Unit Table 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 141

Population Estimation Unit Table (Oracle table name is POP_ESTN_UNIT) 

 Column name Descriptive name Oracle data type 

1 CN Sequence number VARCHAR2(34) 

2 EVAL_CN Evaluation sequence number VARCHAR2(34) 

3 RSCD Region or station code NUMBER(2) 

4 EVALID Evaluation identifier NUMBER(6) 

5 ESTN_UNIT Estimation unit NUMBER(6) 

6 ESTN_UNIT_DESCR Estimation unit description VARCHAR2(255) 

7 STATECD State code NUMBER(4) 

8 AREALAND_EU Land area within the estimation unit NUMBER(12,2) 

9 AREATOT_EU Total area within the estimation unit NUMBER(12,2) 

10 AREA_USED Area used to calculate all expansion factors NUMBER(12,2) 

11 AREA_SOURCE Area source VARCHAR2(50) 

12 P1PNTCNT_EU Phase 1 point count for the estimation unit NUMBER(12) 

13 P1SOURCE Phase 1 source VARCHAR2(30) 

14 CREATED_BY Created by VARCHAR2(30) 

15 CREATED_DATE Created date DATE 

16 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

17 MODIFIED_BY Modified by VARCHAR2(30) 

18 MODIFIED_DATE Modified date DATE 

19 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (CN) N/A PEU_PK 

Unique (RSCD, EVALID, 

ESTN_UNIT) 

N/A PEU_UK 

Foreign (EVAL_CN) POP_ESTN_UNIT to POP_EVAL PEU_PEV_FK 

 1. CN Sequence number. A unique sequence number used to identify an estimation 

unit record. 

 2. EVAL_CN Evaluation sequence number. Foreign key linking the estimation unit record 

to the evaluation record. 

 3. RSCD Region or Station Code. Identification number of the Forest Service National 

Forest System Region or Station (FIA work unit) that provided the inventory 

data (see appendix C for more information). 

Code Description 

22 Rocky Mountain Research Station (RMRS) 

23 North Central Research Station (NCRS) 

24 Northeastern Research Station (NERS) 

26 Pacific Northwest Research Station (PNWRS) 

27 Pacific Northwest Research Station (PNWRS)-Alaska 

33 Southern Research Station (SRS) 
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142 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 4. EVALID Evaluation identifier. The EVALID code and the RSCD code together 

uniquely identify a set of field plots and associated Phase 1 summary data 

used to make population estimates. 

 5. ESTN_UNIT Estimation unit. The specific geographic area that is stratified. Estimation 

units are often determined by a combination of geographical boundaries, 

sampling intensity and ownership. 

 6. ESTN_UNIT_DESCR 

 Estimation unit description. A description of the estimation unit (e.g., name 

of the county). 

 7. STATECD State code. Bureau of the Census Federal Information Processing Standards 

(FIPS) two-digit code for each State. Refer to appendix C. For evaluations 

that do not conform to the boundaries of a single State the value of 

STATECD should be set to 99. 

 8. AREALAND_EU 

 Land area within the estimation unit. The area of land in acres enclosed by 

the estimation unit. Census water is excluded. 

 9. AREATOT_EU 

 Total area within the estimation unit. This includes land and census water 

enclosed by the estimation unit. 

 10. AREA_USED Area used to calculate all expansion factors. Is equivalent to AREATOT_EU 

if a station estimates all area, including census water; and to 

AREALAND_EU if a station estimates land area only. 

 11. AREA_SOURCE 

 Area Source. Identifies the source of the area numbers. Usually the area 

source is either the U.S. Census Bureau or area estimates based on pixel 

counts. Example values are “US CENSUS 2000” or “PIXEL COUNT.” 

 12. P1PNTCNT_EU 

 Phase 1 point count for the estimation unit. For remotely sensed data this will 

be the total number of pixels in the estimation unit. 

 13. P1SOURCE Phase 1 source. Identifies the Phase 1 data source used for this stratification. 

Examples are NLCD and AERIAL PHOTOS. 

 14. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 143

 15. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 16. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 17. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 18. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY 

 19. MODIFIED_IN _INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 
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144 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Population Evaluation Table (Oracle table name is POP_EVAL) 

 Column name Descriptive name Oracle data type 

1 CN Sequence number VARCHAR2(34) 

2 RSCD Region or Station code NUMBER(2) 

3 EVALID Evaluation identifier NUMBER(6) 

4 EVAL_DESCR Evaluation description VARCHAR2(255) 

5 STATECD State code NUMBER(4) 

6 LOCATION_NM Location name VARCHAR2(255) 

7 REPORT_YEAR_NM Report year name VARCHAR2(255) 

8 NOTES Notes VARCHAR2(2000) 

9 CREATED_BY Created by VARCHAR2(30) 

10 CREATED_DATE Created date DATE 

11 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

12 MODIFIED_BY Modified by VARCHAR2(30) 

13 MODIFIED_DATE Modified date DATE 

14 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

15 START_INVYR Start inventory year NUMBER(4) 

16 END_INVYR End inventory year NUMBER(4) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (CN) N/A PEV_PK 

Unique (RSCD, EVALID) N/A PEV_UK 

 1. CN Sequence number. A unique sequence number used to identify an evaluation 

record. 

 2. RSCD Region or Station Code. Identification number of the Forest Service National 

Forest System Region or Station (FIA work unit) that provided the inventory 

data (see appendix C for more information). 

Code Description 

22 Rocky Mountain Research Station (RMRS) 

23 North Central Research Station (NCRS) 

24 Northeastern Research Station (NERS) 

26 Pacific Northwest Research Station (PNWRS) 

27 Pacific Northwest Research Station (PNWRS)-Alaska 

33 Southern Research Station (SRS) 

 3. EVALID Evaluation identifier. The EVALID code and the RSCD code together 

uniquely identify a set of field plots and associated Phase 1 summary data 

used to make population estimates. 

 4. EVAL_DESCR Evaluation description. A description of the area being evaluated (often a 

State), the time period of the evaluation, and the type of estimates the 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 145

evaluation can be used to compute (i.e., all lands, area, volume, growth, 

removals, and mortality). 

 5. STATECD State code. Bureau of the Census Federal Information Processing Standards 

(FIPS) two-digit code for each State. Refer to appendix C. 

 6. LOCATION_NM 

 Location name. Geographic area as it would appear in the title of a report. 

 7. REPORT_YEAR_NM 

 Report year name. The data collection years that would appear in the title of a 

report. 

 8. NOTES Notes. Notes should include information about the stratification method. May 

include citation for any publications that used the evaluation. 

 9. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 10. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 11. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 12. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 13. MODIFIED_DATE 

 Modified date The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 14. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 
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146 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 15. START_INVYR 

 Start inventory year. The starting year for the data included in the evaluation. 

 16. END_INVYR End inventory year. The ending year for the data included in the evaluation. 
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Population Evaluation Attribute Table (Oracle table name is POP_EVAL_ATTRIBUTE) 

 Column name Descriptive name Oracle data type 

1 CN Sequence number VARCHAR2(34) 

2 EVAL_CN Evaluation sequence number VARCHAR2(34) 

3 ATTRIBUTE_NBR Attribute number NUMBER(3) 

4 STATECD State code NUMBER(4) 

5 CREATED_BY Created by VARCHAR2(30) 

6 CREATED_DATE Created date DATE 

7 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

8 MODIFIED_BY Modified by VARCHAR2(30) 

9 MODIFIED_DATE Modified date DATE 

10 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

Type of key Column(s) order Tables to link Abbreviated notation 

Unique (EVAL_CN, 

ATTRIBUTE_NBR) 

N/A PEA_UK 

Foreign (ATTRIBUTE_NBR) POP_EVAL_ATTRIBUTE to 

REF_POP_ATTRIBUTE 

PEA_PAE_FK 

 (EVAL_CN) POP_EVAL_ATTRIBUTE to 

POP_EVAL 

PEA_PEV_FK 

 1. CN Sequence number. A unique sequence number used to identify an evaluation 

attribute record. 

 2. EVAL_CN Evaluation sequence number. Foreign key linking the population evaluation 

attribute record to the population evaluation record. 

 3. ATTRIBUTE_NBR 

 Attribute number. Foreign key linking the population evaluation attribute 

record to the reference population attribute record. 

 4. STATECD State code. Bureau of the Census Federal Information Processing Standards 

(FIPS) two-digit code for each State. Refer to appendix C. 

 5. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 6. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 
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148 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 7. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 8. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 9. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 10. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 
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Population Evaluation Group Table (Oracle table name is POP_EVAL_GRP) 

Column name Descriptive name Oracle data type 

1 CN Sequence number VARCHAR2(34) 

2 EVAL_CN_FOR_EXPALL Evaluation sequence number for 

expansions of all plots VARCHAR2(34) 

3 EVAL_CN_FOR_EXPCURR Evaluation sequence number for 

expansions of current area VARCHAR2(34) 

4 EVAL_CN_FOR_EXPVOL Evaluation sequence number for 

expansions of volume VARCHAR2(34) 

5 EVAL_CN_FOR_EXPGROW Evaluation sequence number for 

expansions of growth VARCHAR2(34) 

6 EVAL_CN_FOR_EXPMORT Evaluation sequence number for 

expansions of mortality VARCHAR2(34) 

7 EVAL_CN_FOR_EXPREMV Evaluation sequence number for 

expansions of removals VARCHAR2(34) 

8 RSCD Region or Station code NUMBER(2) 

9 EVAL_GRP Evaluation group NUMBER(6) 

10 EVAL_GRP_DESCR Evaluation group description VARCHAR2(255) 

11 STATECD State code NUMBER(4) 

12 LAND_ONLY Land only VARCHAR2(1) 

13 CREATED_BY Created by VARCHAR2(30) 

14 CREATED_DATE Created date DATE 

15 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

16 MODIFIED_BY Modified by VARCHAR2(30) 

17 MODIFIED_DATE Modified date DATE 

18 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

19 NOTES Notes VARCHAR2(2000) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (CN) N/A PEG_PK 

Unique (RSCD, EVAL_GRP) N/A PEG_UK 

Foreign (EVAL_CN_FOR_EXPALL) POP_EVAL_GRP to 

POP_EVAL 

PEG_PEV_FK 

 (EVAL_CN_FOR_EXPCURR) POP_EVAL_GRP to 

POP_EVAL 

PEG_PEV_FK_2 

 (EVAL_CN_FOR_EXPGROW) POP_EVAL_GRP to 

POP_EVAL 

PEG_PEV_FK_3 

 (EVAL_CN_FOR_EXPMORT) POP_EVAL_GRP to 

POP_EVAL 

PEG_PEV_FK_4 

 (EVAL_CN_FOR_EXPREMV) POP_EVAL_GRP to 

POP_EVAL 

PEG_PEV_FK_5 

 (EVAL_CN_FOR_EXPVOL) POP_EVAL_GRP to 

POP_EVAL 

PEG_PEV_FK_6 

 1. CN Sequence number. A unique sequence number used to identify an evaluation 

group record. 
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150 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 2. EVAL_CN_FOR_EXPALL 

 Evaluation sequence number for expansions of all plots. This attribute links 

to the POP_EVAL.CN on the evaluation record. When this attribute is 

populated, it points to the evaluation used to estimate total area, including 

both sampled and nonsampled plots. Users must first obtain the correct 

sequence number in this attribute in order to run queries like those shown in 

chapter 4. This attribute will be dropped in version 5.0. 

 3. EVAL_CN_FOR_EXPCURR 

 Evaluation sequence number for expansions of current area. This attribute 

links to the POP_EVAL.CN on the evaluation record. When this attribute is 

populated, it points to the evaluation used to estimate total area, using only 

sampled plots. Users must first obtain the correct sequence number in this 

attribute in order to run queries like those shown in chapter 4. This attribute 

will be dropped in version 5.0. 

 4. EVAL_CN_FOR_EXPVOL 

 Evaluation sequence number for expansions of volume. This attribute links to 

the POP_EVAL.CN of the evaluation record. When this attribute is 

populated, it points to the evaluation used to estimate volume, biomass or 

number of trees, based on the sampled plots within the population that 

qualify for volume estimates. Users must first obtain the correct sequence 

number in this attribute in order to run queries like those shown in chapter 4. 

This attribute will be dropped in version 5.0. 

 5. EVAL_CN_FOR_EXPGROW 

 Evaluation sequence number for expansions of growth. This attribute links to 

the POP_EVAL.CN of the evaluation record. When this attribute is 

populated, it points to the evaluation used to estimate net average annual 

growth, based on the remeasured plots within the population that qualify for 

growth estimates. Users must first obtain the correct sequence number in this 

attribute in order to run queries like those shown in chapter 4. This attribute 

will be dropped in version 5.0. 

 6. EVAL_CN_FOR_EXPMORT 

 Evaluation sequence number for expansions of mortality. This attribute links 

to the POP_EVAL.CN of the evaluation record. When this attribute is 

populated, it points to the evaluation used to estimate average annual 

mortality, based on the remeasured plots within the population that qualify 

for mortality estimates. Users must first obtain the correct sequence number 

in this attribute in order to run queries like those shown in chapter 4. This 

attribute will be dropped in version 5.0. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 151

 7. EVAL_CN_FOR_EXPREMV 

 Evaluation sequence number for expansions of removals. This attribute links 

to the POP_EVAL.CN of the evaluation record. When this attribute is 

populated, it points to the evaluation used to estimate annual removals, based 

on the remeasured plots within the population that qualify for removals 

estimates. Users must first obtain the correct sequence number in this 

attribute in order to run queries like those shown in chapter 4. This attribute 

will be dropped in version 5.0. 

 8. RSCD Region or Station Code. Identification number of the Forest Service National 

Forest System Region or Station (FIA work unit) that provided the inventory 

data (see appendix C for more information). 

Code Description 

22 Rocky Mountain Research Station (RMRS) 

23 North Central Research Station (NCRS) 

24 Northeastern Research Station (NERS) 

26 Pacific Northwest Research Station (PNWRS) 

27 Pacific Northwest Research Station (PNWRS)-Alaska 

33 Southern Research Station (SRS) 

 9. EVAL_GRP Evaluation group. An evaluation group identifies the evaluations that were 

used in producing a core set of tables. In some cases one evaluation will be 

used for area and volume and another evaluation for growth, removals and 

mortality. The value of this attribute is used to select the appropriate State 

and year of interest to produce a set of summary tables. 

 10. EVAL_GRP_DESCR 

 Evaluation group description. A description of the evaluation group that 

includes the State and range of years for the evaluation, for example, 

“Minnesota: 1004;2005;2006;2007;2008”. This is useful to include in a 

summary report to clearly identify the source of the data. 

 11. STATECD State code. Bureau of the Census Federal Information Processing Standards 

(FIPS) two-digit code for each State. Refer to appendix C. For evaluations 

that do not conform to the boundaries of a single State the value of 

STATECD should be set to 99. 

 12. LAND_ONLY Land only. A code indicating area used in stratifying evaluations. See 

POP_ESTN_UNIT.AREA_SOURCE for more information. 

Code Description 

Y Only census land was used in the stratification process. 

N Census land and water were used in the stratification process. 

 13. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 
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152 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 14. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 15. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 16. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 17. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 18. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 

 19. NOTES Notes. An optional item where additional information about the evaluation 

group may be stored.
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Population Evaluation Type Table (Oracle table name is POP_EVAL_TYP) 

 Column name Descriptive name Oracle data type 

1 EVAL_GRP_CN Evaluation group sequence number VARCHAR2(34) 

2 EVAL_CN Evaluation sequence number VARCHAR2(34) 

3 EVAL_TYP Evaluation type VARCHAR2(15) 

4 STATECD State code NUMBER(4) 

5 CREATED_BY Created by VARCHAR2(30) 

6 CREATED_DATE Created date DATE 

7 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

8 MODIFIED_BY Modified by VARCHAR2(30) 

9 MODIFIED_DATE Modified date DATE 

10 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

11 CN Sequence number VARCHAR2(34) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (CN) N/A PET_PK 

Unique (EVAL_GRP_CN, 

EVAL_CN, EVAL_TYP) 

N/A PET_UK 

Foreign (EVAL_GRP_CN) POP_EVAL_TYP to 

POP_EVAL_GRP 

PET_PEG_FK 

(EVAL_CN) POP_EVAL_TYP to POP_EVAL PET_PEV_FK 

 (EVAL_TYP) POP_EVAL_TYP to 

REF_POP_EVAL_TYP_DESCR 

PET_PED_FK 

 1. EVAL_GRP_CN 

 Evaluation group sequence number. Foreign key linking the population 

evaluation type record to the population evaluation group record. 

 2. EVAL_CN Evaluation sequence number. Foreign key linking the population evaluation 

type record to the population evaluation record. 

 3. EVAL_TYP Evaluation type. Describes the type of evaluation. Evaluation type is needed 

to generate summary reports for an inventory. For example, a specific 

evaluation is associated with the evaluation for volume (Expvol). At the 

present time, seven types of evaluations can be produced. See also the 

REF_POP_EVAL_TYP_DESCR table. 

Evaluation type values 

Expall 

Expchng 

Expcurr 

Expgrow 

Expmort 

Expremv 

Expvol 
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154 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 4. STATECD State code. Bureau of the Census Federal Information Processing Standards 

(FIPS) two-digit code for each State. Refer to appendix C. 

 5. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 6. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 7. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 8. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 9. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 10. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 

 11. CN Sequence number. A unique sequence number used to identify a population 

evaluation type record 
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Population Plot Stratum Assignment Table (Oracle table name is 

POP_PLOT_STRATUM_ASSGN) 

 Colum name Descriptive name Oracle data type 

1 CN Sequence number VARCHAR2(34) 

2 STRATUM_CN Stratum sequence number VARCHAR2(34) 

3 PLT_CN Plot sequence number VARCHAR2(34) 

4 STATECD State code NUMBER(4) 

5 INVYR Inventory year NUMBER(4) 

6 UNITCD Survey unit code NUMBER(2) 

7 COUNTYCD County code NUMBER(3) 

8 PLOT Phase 2 plot number NUMBER(5) 

9 RSCD Region or Station code NUMBER(2) 

10 EVALID Evaluation identifier NUMBER(6) 

11 ESTN_UNIT Estimation unit NUMBER(6) 

12 STRATUMCD Stratum code NUMBER(6) 

13 CREATED_BY Created by VARCHAR2(30) 

14 CREATED_DATE Created date DATE 

15 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

16 MODIFIED_BY Modified by VARCHAR2(30) 

17 MODIFIED_DATE Modified date DATE 

18 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (CN) N/A PPSA_PK 

Unique (PLT_CN, 

STRATUM_CN) 

N/A PPSA_UK 

 (STATECD, INVYR, 

UNITCD, COUNTYCD, 

PLOT, RSCD, EVALID, 

ESTN_UNIT, 

STRATUMCD) 

N/A PPSA_UK2 

Foreign (PLT_CN) POP_PLOT_STRATUM_ASSGN 

to PLOT 

PPSA_PLT_FK 

 (STRATUM_CN) POP_PLOT_STRATUM_ASSGN 

to POP_STRATUM 

PPSA_PSM_FK 

 1. CN Sequence number. A unique sequence number used to identify a population 

plot stratum assignment record. 

 2. STRATUM_CN 

 Stratum sequence number. Foreign key linking the population plot stratum 

assignment record to the population stratum record. 
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156 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 3. PLT_CN Plot sequence number. Foreign key linking the population plot stratum 

assignment record to the plot record. 

 4. STATECD State code. Bureau of the Census Federal Information Processing Standards 

(FIPS) two-digit code for each State. Refer to appendix C. 

 5. INVYR Inventory year. The year that best represents when the inventory data were 

collected. Under the annual inventory system, a group of plots is selected 

each year for sampling. The selection is based on a panel system. INVYR is 

the year in which the majority of plots in that group were collected (plots in 

the group have the same panel and, if applicable, subpanel). Under periodic 

inventory, a reporting inventory year was selected, usually based on the year 

in which the majority of the plots were collected or the mid-point of the years 

over which the inventory spanned. For either annual or periodic inventory, 

INVYR is not necessarily the same as MEASYEAR. 

 Exceptions: 

 INVYR = 9999. INVYR is set to 9999 to distinguish Phase 3 plots taken by 

the western FIA work units that are “off subpanel.” This is due to differences 

in measurement intervals between Phase 3 (measurement interval = 5 years) 

and Phase 2 (measurement interval = 10 years) plots. Only users interested in 

performing certain Phase 3 data analyses should access plots with this 

anomalous value in INVYR. 

 INVYR <100. INVYR <100 indicates that population estimates were derived 

from a pre-NIMS regional processing system and the same plot either has 

been or may soon be re-processed in NIMS as part of a separate evaluation. 

The NIMS processed copy of the plot follows the standard INVYR format. 

This only applies to plots collected in the South (RSCD = 33) with the 

national design or a similar regional design (PLOT.DESIGNCD = 1 or 220-

233) that were collected when the inventory year was 1998 through 2005. 

 INVYR = 98 is equivalent to 1998 but processed through regional system 

 INVYR = 99 is equivalent to 1999 but processed through regional system 

 INVYR = 0 is equivalent to 2000 but processed through regional system 

 INVYR = 1 is equivalent to 2001 but processed through regional system 

 INVYR = 2 is equivalent to 2002 but processed through regional system 

 INVYR = 3 is equivalent to 2003 but processed through regional system 

 INVYR = 4 is equivalent to 2004 but processed through regional system 

 INVYR = 5 is equivalent to 2005 but processed through regional system 

 6. UNITCD Survey unit code. Forest Inventory and Analysis survey unit identification 

number. Survey units are usually groups of counties within each State. For 

periodic inventories, Survey units may be made up of lands of particular 

owners. Refer to appendix C for codes. 

 7. COUNTYCD County code. The identification number for a county, parish, watershed, 

borough, or similar governmental unit in a State. FIPS codes from the Bureau 

of the Census are used. Refer to appendix C for codes. 
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 8. PLOT Phase 2 plot number. An identifier for a plot. Along with INVYR, 

STATECD, UNITCD, COUNTYCD, PLOT may be used to uniquely identify 

a plot. 

 9. RSCD Region or Station Code. Identification number of the Forest Service National 

Forest System Region or Station (FIA work unit) that provided the inventory 

data (see appendix C for more information). 

Code Description 

22 Rocky Mountain Research Station (RMRS) 

23 North Central Research Station (NCRS) 

24 Northeastern Research Station (NERS) 

26 Pacific Northwest Research Station (PNWRS) 

27 Pacific Northwest Research Station (PNWRS) - Alaska 

33 Southern Research Station (SRS) 

 10. EVALID Evaluation identifier. The EVALID code and the RSCD code together 

uniquely identify a set of field plots and associated Phase 1 summary data 

used to make population estimates. 

 11. ESTN_UNIT Estimation unit. A geographic area upon which stratification is performed. 

Sampling intensity is uniform within an estimation unit. 

 12. STRATUMCD Stratum code. The code used for a particular stratum, which is unique within 

an RSCD, EVALID, ESTN_UNIT. 

 13. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 14. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 15. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 16. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 
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158 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 17. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 18. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 159

Population Stratum Table (Oracle table name is POP_STRATUM) 

 Column name Descriptive name Oracle data type 

1 CN Sequence number VARCHAR2(34) 

2 ESTN_UNIT_CN Estimation unit sequence number VARCHAR2(34) 

3 RSCD Region or Station code NUMBER(2) 

4 EVALID Evaluation identifier NUMBER(6) 

5 ESTN_UNIT Estimation unit NUMBER(6) 

6 STRATUMCD Stratum code NUMBER(6) 

7 STRATUM_DESCR Stratum description VARCHAR2(255) 

8 STATECD State code NUMBER(4) 

9 P1POINTCNT Phase 1 point count NUMBER(12) 

10 P2POINTCNT Phase 2 point count NUMBER(12) 

11 EXPNS Expansion factor NUMBER 

12 ADJ_FACTOR_MACR Adjustment factor for the macroplot NUMBER(5,4) 

13 ADJ_FACTOR_SUBP Adjustment factor for the subplot NUMBER(5,4) 

14 ADJ_FACTOR_MICR Adjustment factor for the microplot NUMBER(5,4) 

15 CREATED_BY Created by VARCHAR2(30) 

16 CREATED_DATE Created date DATE 

17 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

18 MODIFIED_BY Modified by VARCHAR2(30) 

19 MODIFIED_DATE Modified date DATE 

20 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (CN) N/A PSM_PK 

Unique (RSCD, EVALID, ESTN_UNIT, 

STRATUMCD) 

N/A PSM_UK 

Foreign (ESTN_UNIT_CN) POP_STRATUM to 

POP_ESTN_UNIT 

PSM_PEU_FK 

 1. CN Sequence number. A unique sequence number used to identify a stratum 

record. 

 2. ESTN_UNIT_CN 

 Estimation unit sequence number. Foreign key linking the stratum record to 

the estimation unit record. 

 3. RSCD Region or Station Code. Identification number of the Forest Service National 

Forest System Region or Station (FIA work unit) that provided the inventory 

data (see appendix C for more information). 
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160 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Code Description 

22 Rocky Mountain Research Station (RMRS) 

23 North Central Research Station (NCRS) 

24 Northeastern Research Station (NERS) 

26 Pacific Northwest Research Station (PNWRS) 

27 Pacific Northwest Research Station (PNWRS)-Alaska 

33 Southern Research Station (SRS) 

 4. EVALID Evaluation identifier. The EVALID code and the RSCD code together 

uniquely identify a set of field plots and associated Phase 1 summary data 

used to make population estimates. 

 5. ESTN_UNIT Estimation unit. The particular geographic area for which a particular 

computation applies. Estimation units are determined by a combination of 

sampling intensity and geographical boundaries. 

 6. STRATUMCD Stratum code. A number used to uniquely identify a stratum within an 

estimation unit. 

 7. STRATUM_DESCR 

 Stratum description. Strata are usually based on land use (e.g., forest or 

nonforest) but may also be based on other criteria such as ownership (e.g., 

private/public/national forest). 

 8. STATECD State code. Bureau of the Census Federal Information Processing Standards 

(FIPS) two-digit code for each State. Refer to appendix C. For evaluations 

that do not conform to the boundaries of a single State the value of 

STATECD should be set to 99. 

 9. P1POINTCNT Phase 1 point count. The number of basic units (pixels or points) in the 

stratum. 

 10. P2POINTCNT Phase 2 point count. The number of field plots that are within the stratum. 

 11. EXPNS Expansion factor. The area, in acres, that a stratum represents divided by the 

number of sampled plots in that stratum. This attribute can be used to obtain 

estimates of population area when summed across all the plots in the 

population of interest. Refer to chapter 4 for detailed examples. 

 12. ADJ_FACTOR_MACR 

 Adjustment factor for the macroplot. A value that adjusts the population 

estimates to account for partially nonsampled plots (access denied and 

hazardous portions). It is used with condition proportion 

(COND.CONDPROP_UNADJ) and area expansion (EXPNS) to provide area 

estimates, when COND.PROP_BASIS = “MACR”. ADJ_FACTOR_MACR 

is also used with EXPNS and trees per acre unadjusted (TREE.TPA_UNADJ, 

TREE.TPAMORT_UNADJ, TREE.TPAREMV_UNADJ, 

TREE.TPAGROW_UNADJ) to provide tree estimates for sampled land. If a 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 161

macroplot was not installed, this attribute is left blank (null). Refer to chapter 

4 for detailed examples. 

 13. ADJ_FACTOR_SUBP 

 Adjustment factor for the subplot. A value that adjusts the population 

estimates to account for partially nonsampled plots (access denied and 

hazardous portions). It is used with condition proportion 

(COND.CONDPROP_UNADJ) and area expansion (EXPNS) to provide area 

estimates, when COND.PROP_BASIS = “SUBP”. ADJ_FACTOR_SUBP is 

also used with EXPNS and trees per acre unadjusted (TREE.TPA_UNADJ, 

TREE.TPAMORT_UNADJ, TREE.TPAREMV_UNADJ, 

TREE.TPAGROW_UNADJ) to provide tree estimates for sampled land. 

Refer to chapter 4 for detailed examples. 

 14. ADJ_FACTOR_MICR 

 Adjustment factor for the microplot. A value that adjusts population 

estimates to account for partially nonsampled plots (access denied and 

hazardous portions). It is used with POP_STRATUM.EXPNS and seedlings 

per acre unadjusted (SEEDLING.TPA_UNADJ) or saplings per acre 

unadjusted (TREE.TPA_UNADJ where TREE DIA <5.0) to provide tree 

estimates for sampled land. Refer to chapter 4 for detailed examples. 

 15. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 16. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 17. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 18. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 19. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 
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162 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 20. MODIFIED_IN _INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 
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Reference Population Attribute Table (Oracle table name is REF_POP_ATTRIBUTE) 

 Column name Descriptive name Oracle data type 

1 CN Sequence number VARCHAR2(34) 

2 ATTRIBUTE_NBR Attribute number NUMBER(3) 

3 ATTRIBUTE_DESCR Attribute description VARCHAR2(255) 

4 EXPRESSION Expression VARCHAR2(2000) 

5 WHERE_CLAUSE Where clause VARCHAR2(255) 

6 CREATED_BY Created by VARCHAR2(30) 

7 CREATED_DATE Created date DATE 

8 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

9 MODIFIED_BY Modified by VARCHAR2(30) 

10 MODIFIED_DATE Modified date DATE 

11 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

12 FOOTNOTE Footnote VARCHAR2(2000) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (ATTRIBUTE_NBR) N/A PAE_PK 

 1. CN Sequence number. A unique sequence number used to identify a reference 

population attribute record. 

 2. ATTRIBUTE_NBR 

 Attribute number. A numeric code used to identify an attribute record. See 

codes and descriptions in chapter 4, table 4.1. 

 3. ATTRIBUTE_DESCR 

 Attribute description. Examples include “Area of forestland (acres)” or “All 

live biomass on forestland oven-dry (short tons).” See codes and descriptions 

in chapter 4, table 4.1. 

 4. EXPRESSION 

 Expression. SQL expression that identifies variables that are used to generate 

population estimate identified by ATTRIBUTE_DESCR (chapter 4, table 

4.2). 

 5. WHERE_CLAUSE 

 Where clause. SQL where clause that identifies the appropriate method for 

joining tables and screening records to generate population estimate 

identified by REF_POP_ATTRIBUTE.ATTRIBUTE_DESCR (chapter 4, 

table 4.2). 
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164 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 6. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 7. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 8. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 9. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 10. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 11. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 

 12. FOOTNOTE Footnote. Intentionally left blank. Will be populated in verion 5.0 
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Reference Population Evaluation Type Description Table (Oracle table name is 

REF_POP_EVAL_TYP_DESCR) 

 Column name Descriptive name Oracle data type 

1 EVAL_TYP Evaluation type VARCHAR2(15) 

2 EVAL_TYP_DESCR Evaluation type description VARCHAR2(255) 

3 CREATED_BY Created by VARCHAR2(30) 

4 CREATED_DATE Created date DATE 

5 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

6 MODIFIED_BY Modified by VARCHAR2(30) 

7 MODIFIED_DATE Modified date DATE 

8 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

9 CN Sequence number VARCHAR2(34) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (CN) N/A PED_PK 

Unique (EVAL_TYP) N/A PED_UK 

 1. EVAL_TYP Evaluation type. Evaluation types (EVAL_TYP) and the description of the 

evaluation types (EVAL_TYP_DESCR) are: 

Evaluation type Evaluation type description 

Expall All plots: sampled and nonsampled 

Expchng Sampled plots used for area change estimates 

Expcurr Sampled plots used for current area estimates 

Expgrow Sampled plots used for tree growth estimates 

Expmort Sampled plots used for tree mortality estimates 

Expremv Sampled plots used for tree removal estimates 

Expvol Sampled plots used for tree inventory estimates 

 2. EVAL_TYP_DESCR 

 Evaluation type description. The description for each evaluation type 

(EVAL_TYP). See the list of codes and descriptions in EVAL_TYP. 

. 

 3. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 4. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 5. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 
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166 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

stores that information to determine on which computer the record was 

created. 

 6. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 7. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 8. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 

 9. CN Sequence number. A unique sequence number used to identify a reference 

population evaluation type description record. 
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Chapter 3. Reference Forest Type Table 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 167

Reference Forest Type Table (Oracle table name is REF_FOREST_TYPE) 

 Column name Descriptive name Oracle data type 

1 VALUE Value NUMBER(3) 

2 MEANING Meaning VARCHAR2(80) 

3 TYPGRPCD Forest type group code NUMBER(3) 

4 MANUAL_START Manual start NUMBER(3,1) 

5 MANUAL_END Manual end NUMBER(3,1) 

6 ALLOWED_IN_FIELD Allowed in field VARCHAR2(1) 

7 CREATED_BY Created by VARCHAR2(30) 

8 CREATED_DATE Created date DATE 

9 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

10 MODIFIED_BY Modified by VARCHAR2(30) 

11 MODIFIED_DATE Modified date DATE 

12 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (VALUE) N/A RFT_PK 

 1. VALUE Value. A code used for the forest type (COND.FORTYPCD, 

COND.FLDTYPCD, COND.FORTYPCDCALC). Refer to appendix D. 

 2. MEANING Meaning. The descriptive name corresponding with the forest type code 

(VALUE). The names associated with these codes are used to label rows or 

columns in National standard presentation tables. Refer to appendix D. 

 3. TYPGRPCD Forest type group code. A code assigned to individual forest types in order to 

group them for reporting purposes. Refer to appendix D. 

 4. MANUAL_START 

 Manual start. The first version of the Field Guide (PLOT.MANUAL) that the 

forest type code (VALUE) began to be used. 

 5. MANUAL_END 

 Manual end. The last version of the Field Guide (PLOT.MANUAL) that the 

forest type code (VALUE) was valid. When MANUAL_END is blank (null), 

the code is still valid. 

 6. ALLOWED_IN_FIELD 

 Allowed in field. An indicator to show if a code (VALUE) is allowed to be 

used by the field crews. This is a Yes/No (Y/N) field. Specifically, forest type 

group codes are not allowed in the Field Guide nor is the code for a 

nonstocked forest type (VALUE = 999). 
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168 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 7 CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 8. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 9. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 10. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 11. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 12. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 169

Reference Species Table (Oracle table name is REF_SPECIES) 

 Column name Descriptive name Oracle data type 

1 SPCD Species code NUMBER 

2 COMMON_NAME Common name of species VARCHAR2(100) 

3 GENUS Genus VARCHAR2(40) 

4 SPECIES Species name VARCHAR2(50) 

5 VARIETY Variety VARCHAR2(50) 

6 SUBSPECIES Subspecies name VARCHAR2(50) 

7 SPECIES_SYMBOL Species symbol VARCHAR2(8) 

8 E_SPGRPCD East species group code NUMBER(2) 

9 W_SPGRPCD West species group code NUMBER(2) 

10 MAJOR_SPGRPCD Major species group code NUMBER(1) 

11 STOCKING_SPGRPCD Stocking species group code NUMBER(3) 

12 FOREST_TYPE_SPGRPCD Forest type species group code NUMBER(3) 

13 EXISTS_IN_NCRS Exists in the North Central Research 

Station States VARCHAR2(1) 

14 EXISTS_IN_NERS Exists in the Northeastern Research 

Station States VARCHAR2(1) 

15 EXISTS_IN_PNWRS Exists in the Pacific Northwest 

Research Station States VARCHAR2(1) 

16 EXISTS_IN_RMRS Exists in the Rocky Mountain 

Research Station States VARCHAR2(1) 

17 EXISTS_IN_SRS Exists in the Southern Research 

Station States VARCHAR2(1) 

18 SITETREE Site tree VARCHAR2(1) 

19 SFTWD_HRDWD Softwood or hardwood VARCHAR2(1) 

20 ST_EXISTS_IN_NCRS Site tree exists in the North Central 

Research Station region VARCHAR2(1) 

21 ST_EXISTS_IN_NERS Site tree exists in the Northeastern 

Research Station region VARCHAR2(1) 

22 ST_EXISTS_IN_PNWRS Site tree exists in the Pacific 

Northwest Research Station region VARCHAR2(1) 

23 ST_EXISTS_IN_RMRS Site tree exists in the Rocky 

Mountain Research Station region VARCHAR2(1) 

24 ST_EXISTS_IN_SRS Site tree exists in the Southern 

Research Station region VARCHAR2(1) 

25 EAST East VARCHAR2(1) 

26 WEST West VARCHAR2(1) 

27 WOODLAND Woodland species VARCHAR2(1) 

28 MANUAL_START Manual start NUMBER(3,1) 

29 MANUAL_END Manual end NUMBER(3,1) 

30 CREATED_BY Created by VARCHAR2(30) 

31 CREATED_DATE Created date DATE 

32 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 
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170 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 Column name Descriptive name Oracle data type 

33 MODIFIED_BY Modified by VARCHAR2(30) 

34 MODIFIED_DATE Modified date DATE 

35 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

36 CORE Core VARCHAR2(1) 

37 JENKINS_SPGRPCD Jenkins species group code NUMBER(8,5) 

38 JENKINS_TOTAL_B1 Jenkins total B1 NUMBER(8,5) 

39 JENKINS_TOTAL_B2 Jenkins total B2 NUMBER(8,5) 

40 JENKINS_STEM_WOOD_RATIO_B1 Jenkins stem wood ratio B1 NUMBER(8,5) 

41 JENKINS_STEM_WOOD_RATIO_B2 Jenkins stem wood ratio B2 NUMBER(8,5) 

42 JENKINS_STEM_BARK_RATIO_B1 Jenkins stem bark ratio B1 NUMBER(8,5) 

43 JENKINS_STEM_BARK_RATIO_B2 Jenkins stem bark ratio B2 NUMBER(8,5) 

44 JENKINS_FOLIAGE_RATIO_B1 Jenkins foliage ratio B1 NUMBER(8,5) 

45 JENKINS_FOLIAGE_RATIO_B2 Jenkins foliage ratio B2 NUMBER(8,5) 

46 JENKINS_ROOT_RATIO_B1 Jenkins root ratio B1 NUMBER(8,5) 

47 JENKINS_ROOT_RATIO_B2 Jenkins root ratio B2 NUMBER(8,5) 

48 JENKINS_SAPLING_ADJUSTMENT Jenkins sapling adjustment factor NUMBER(8,5) 

49 WOOD_SPGR_GREENVOL_DRYWT Green specific gravity wood (green 

volume and oven-dry weight) NUMBER(8,5) 

50 WOOD_SPGR_GREENVOL_DRYWT_

CIT Green specific gravity wood citation NUMBER(7) 

51 BARK_SPGR_GREENVOL_DRYWT Green specific gravity bark (green 

volume and oven-dry weight) NUMBER(8,5) 

52 BARK_SPGR_GREENVOL_DRYWT_ 

CIT Green specific gravity bark citation NUMBER(7) 

53 MC_PCT_GREEN_WOOD Moisture content of green wood as a 

percent of oven-dry weight NUMBER(8,5) 

54 MC_PCT_GREEN_WOOD_CIT Moisture content of green wood 

citation NUMBER(7) 

55 MC_PCT_GREEN_BARK Moisture content of green bark as a 

percent of oven-dry weight NUMBER(8,5) 

56 MC_PCT_GREEN_BARK_CIT Moisture content of green bark 

citation NUMBER(7) 

57 WOOD_SPGR_MC12VOL_DRYWT 

Wood specific gravity (12 percent 

moisture content volume and ovendry weight) 

NUMBER(8,5) 

58 WOOD_SPGR_MC12VOL_DRYWT_ 

CIT 

Wood specific gravity (12 percent 

moisture content volume and ovendry weight) citation 

NUMBER(7) 

59 BARK_VOL_PCT Bark volume as a percent of wood 

volume NUMBER(8,5) 

60 BARK_VOL_PCT_CIT Bark volume as a percent of wood 

volume citation NUMBER(7) 

61 RAILE_STUMP_DOB_B1 Raile stump diameter outside bark 

equation coefficient B1 NUMBER(8,5) 

62 RAILE_STUMP_DIB_B1 Raile stump diameter inside bark 

equation coefficient B1 NUMBER(8,5) 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 171

 Column name Descriptive name Oracle data type 

63 RAILE_STUMP_DIB_B2 Raile stump diameter inside bark 

equation coefficient B2 NUMBER(8,5) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (SPCD) N/A SPC_PK 

Unique (SPECIES_SYMBOL) N/A SPC_UK 

Coefficients for calculating total aboveground biomass based on Jenkins and others (2003) 

equations are included in the REF_SPECIES table. Coefficients for calculating biomass 

components (stem wood, stem bark, foliage, coarse roots, stump, and sapling) are also included in 

the REF_SPECIES table. Biomass in branches and treetops (tops and limbs) may be found by 

subtracting the biomass in stem wood, stem bark, foliage, and stump from total aboveground 

biomass. Heath and others (2009) provides an overview of the historical use of Jenkins and others 

(2003) for biomass estimation for the U.S. forest greenhouse gas inventory (U.S. Environmental 

Protection Agency 2008) and an overview of the approach of the new biomass equations used for 

FIA data. 

 1. SPCD Species code. An FIA tree species code. Refer to appendix F for codes. 

 2. COMMON_NAME 

 Common name. Common name of the species. Refer to appendix F. 

 3. GENUS Genus. The genus name associated with the FIA tree species code. Refer to 

appendix F. 

 4. SPECIES Species. The species name associated with the FIA tree species code. Refer to 

appendix F. 

 5. VARIETY Variety. The variety name associated with the FIA tree species code. 

 6. SUBSPECIES Subspecies. The subspecies name associated with the FIA tree species code. 

 7. SPECIES_SYMBOL 

 Species symbol. The NRCS PLANTS database code associated with the FIA 

tree species code. 

 8. E_SPGRPCD Eastern species group code. A code indicating the species group assignment 

for eastern species. Depending on the State in which a tree is tallied, either 

the eastern or western species group code is associated with the actual TREE, 

SITETREE, and SEEDLING data. Species group codes and names can be 

found in appendix G. 

 9. W_SPGRPCD Western species group code. A code indicating the FIADB species group 

assignment for western species. Depending on the State in which a tree is 

tallied, either the eastern or western species group code is associated with the 
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172 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

actual TREE, SITETREE, and SEEDLING data. Species group codes and 

names can be found in appendix G. 

 10. MAJOR_SPGRPCD 

 Major species group code. A code indicating the major species group, which 

can be used for reporting purposes. 

Code Description 

1 Pine 

2 Other conifers 

3 Soft hardwood 

4 Hard hardwood 

 11. STOCKING_SPGRPCD 

 Stocking species group code. A code indicating which stocking equation a 

species is assigned. 

Code Description 

1 Spruce-fir 

2 Western larch 

3 Black spruce 

4 Jack pine 

5 Lodgepole pine 

6 Shortleaf pine 

7 Slash pine 

8 Western white pine 

9 Longleaf pine 

10 Ponderosa pine 

11 Red pine 

12 Pond pine 

13 Eastern white pine 

14 Loblolly pine 

15 Douglas-fir 

16 Northern white cedar 

17 Eastern hemlock 

18 Western hemlock 

19 Redwood 

20 Average softwood 

25 Red maple 

26 Red alder 

27 Maple, beech, birch 

28 Paper birch 

29 Oaks and hickory 

30 Black walnut 

31 Sweetgum 

32 Aspen 

33 Cherry, ash, yellow poplar 

35 Basswood 

36 Elm, ash, cottonwood 

37 Average hardwood 

38 Dryland species 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 173

 12. FOREST_TYPE_SPGRPCD 

 Forest type species group code. A code indicating which initial forest type 

group a species is assigned. 

 13. EXISTS_IN_NCRS 

 Exists in the North Central Research Station. Indicates which species are 

valid for North Central Research Station States. Trees that are applicable to 

North Central States are marked with an X. 

 14. EXISTS_IN_NERS 

 Exists in the Northeastern Research Station. Indicates which tree species are 

valid for Northeastern Research Station States. Tree species that are 

applicable to Northeastern States are marked with an X. 

 15. EXISTS_IN_PNWRS 

 Exists in the Pacific Northwest Research Station. Indicates which species are 

valid for Pacific Northwest Research Station States. Tree species that are 

applicable to Pacific Northwest States are marked with an X. 

 16. EXISTS_IN RMRS 

 Exists in the Rocky Mountain Research Station. Indicates which species are 

valid for Rocky Mountain Research Station States. Tree species that are 

applicable to the Rocky Mountain States are marked with an X. 

 17. EXISTS_IN_SRS 

 Exists in the Southern Research Station. Indicates which species are valid for 

Southern Research Station States. Tree species that are applicable to the 

Southern States are marked with an X. 

 18. SITETREE Sitetree. Indicates whether the tree species can be coded as a site tree. Tree 

species that are applicable to have site data collected are marked with an X. 

 19. SFTWD_HRDWD 

 Softwood/ hardwood. Indicates whether the species is a softwood or a 

hardwood. Softwoods are marked with an S and hardwoods with an H. 

 20. ST_EXISTS_IN_NCRS 

 Site tree exists in the North Central Research Station. Indicates whether or 

not the species is valid as a site tree in North Central Research Station States. 

Tree species that are applicable to have site data collected are marked with an 

X. 
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174 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 21. ST_EXISTS_IN_NERS 

 Site tree exists in the Northeastern Research Station. Indicates whether or not 

the species is valid as a site tree in Northeastern Research Station States. Tree 

species that are applicable to have site data collected are marked with an X. 

 22. ST_EXISTS_IN_PNWRS 

 Site tree exists in the Pacific Northwest Research Station. Indicates whether 

or not the species is valid for a site tree in Pacific Northwest Research Station 

States. Tree species that are applicable to have site data collected are marked 

with an X. 

 23. ST_EXISTS_IN RMRS 

 Site tree exists in the Rocky Mountain Research Station. Indicates whether or 

not the species is valid as a site tree in Rocky Mountain Research Station 

States. Tree species that are applicable to have site data collected are marked 

with an X. 

 24. ST_EXISTS_IN_SRS 

 Site tree exists in the Southern Research Station. Indicates whether or not the 

species is valid for a site tree in Southern Research Station States. Tree 

species that are applicable to have site data collected are marked with an X. 

 25. EAST East. Indicates if the species can occur in the Eastern United States. Valid 

eastern species are marked with an E. 

 26. WEST West. Indicates if the species can occur in the Western United States. Valid 

western species are marked with a W. 

 27. WOODLAND Woodland. Indicates if the species is classified as a woodland species, 

meaning that the diameter is measured as root collar. Woodland species are 

marked with an X. 

 28. MANUAL_START 

 Manual start. The first version of the Field Guide (PLOT.MANUAL) that the 

species code was used. 

 29. MANUAL_END 

 Manual end. The last version of the Field Guide (PLOT. MANUAL) that the 

species code was valid. When MANUAL_END is blank (null), the code is 

still valid. 

 30. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 
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Chapter 3. Reference Species Table 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 175

 31. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 32. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 33. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 34. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 35. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 

 36. CORE Core. Indicates that the tree species must be tallied (measured) by all FIA 

work units. Species marked with a Y are core and core optional species are 

marked with an N. 

 37. JENKINS_SPGRPCD 

 Jenkins species group code. A code that identifies a group of similar species, 

which is used to apply the correct biomass estimation equation and 

coefficient developed by Jenkins and others (2003). A specific set of biomass 

equation coefficients are assigned to each group. Additional explanation 

about how to estimate biomass, and when to use a certain set of coefficients, 

is provided in appendix J. 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

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176 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Code Description 

1 Cedar/larch 

2 Douglas-fir 

3 True fir/hemlock 

4 Pine 

5 Spruce 

6 Aspen/alder/cottonwood/willow 

7 Soft maple/birch 

8 Mixed hardwood 

9 Hard maple/oak/hickory/beech 

10 Juniper/oak/mesquite 

 38. JENKINS_TOTAL_B1 

 Jenkins total B1. Jenkins B1 coefficient used to estimate total aboveground 

oven-dry biomass (pounds). This is coefficient B0 from table 4 in Jenkins and 

others (2003). See appendix J for details on biomass equations. 

 Use JENKINS_TOTAL_B1 along with JENKINS_TOTAL_B2 to estimate 

total aboveground biomass (includes stem wood (bole), stump, bark, top, 

limbs, and foliage) with the equation below: 

 Total_agb = (Exp(JENKINS_TOTAL_B1 + JENKINS_TOTAL_B2 * 

ln(DIA*2.54)) * 2.2046) 

JENKINS_SPGRPCD JENKINS_TOTAL_B1 

1 -2.03360 

2 -2.23040 

3 -2.53840 

4 -2.53560 

5 -2.07730 

6 -2.20940 

7 -1.91230 

8 -2.48000 

9 -2.01270 

10 -0.71520 

 39. JENKINS_TOTAL_B2 

 Jenkins total B2. Jenkins B2 coefficient used to estimate total aboveground 

oven-dry biomass (pounds). This is coefficient B1 from table 4 in Jenkins and 

others (2003). See appendix J for details on biomass equations. 

 Use JENKINS_TOTAL_B2 along with JENKINS_TOTAL_B1 to estimate 

total aboveground biomass (includes stem wood (bole), stump, bark, top, 

limbs, and foliage) with the equation below: 

 Total_agb = (Exp(JENKINS_TOTAL_B1 + JENKINS_TOTAL_B2 * 

ln(DIA*2.54)) * 2.2046) 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 177

JENKINS_SPGRPCD JENKINS_TOTAL_B2 

1 2.25920 

2 2.44350 

3 2.48140 

4 2.43490 

5 2.33230 

6 2.38670 

7 2.36510 

8 2.48350 

9 2.43420 

10 1.70290 

 40. JENKINS_STEM_WOOD_RATIO_B1 

 Jenkins stem wood ratio B1. A coefficient used in computing component 

ratio biomass. This is equivalent to coefficient B0 for stem wood from table 6 

in Jenkins and others (2003). The appropriate coefficient to use is based on 

the species category (SFTWD_HRDWD). The stem is defined as that portion 

of the tree from a 1-foot stump to a 4-inch DOB top (i.e., the merchantable 

bole.) See appendix J for details on biomass equations. 

 The average proportion of aboveground biomass in stem wood is calculated 

using this equation: 

 stem_ratio = Exp(JENKINS_STEM_WOOD_RATIO_B1 + 

JENKINS_STEM_WOOD_RATIO_B2 / (DIA*2.54)) 

Species category JENKINS_STEM_WOOD_RATIO_B1 

Softwood (S) -0.3737 

Hardwood (H) -0.3065 

 41. JENKINS_STEM_WOOD_RATIO_B2 

 Jenkins stem wood ratio B2. A coefficient used in computing component 

ratio biomass. This is equivalent to coefficient B1 for stem wood from table 6 

in Jenkins and others (2003). The appropriate coefficient to use is based on 

the species category (SFTWD_HRDWD). The stem is defined as that portion 

of the tree from a 1-foot stump to a 4-inch DOB top (i.e., the merchantable 

bole.) See appendix J for details on biomass equations. 

 The average proportion of aboveground biomass in stem wood is calculated 

using this equation: 

 stem_ratio = Exp(JENKINS_STEM_WOOD_RATIO_B1 + 

JENKINS_STEM_WOOD_RATIO_B2 / (DIA*2.54)) 

Species category JENKINS_STEM_WOOD_RATIO_B2 

Softwood (S) -1.8055 

Hardwood (H) -5.4240 
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178 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 42. JENKINS_STEM_BARK_RATIO_B1 

 Jenkins stem bark ratio B1. A coefficient used in computing component ratio 

biomass. This is equivalent to coefficient B0 for stem bark from table 6 in 

Jenkins and others (2003). The appropriate coefficient to use is based on the 

species category (SFTWD_HRDWD). This ratio estimates bark biomass on 

the stem, defined as that portion of the tree from a 1-foot stump to a 4-inch 

DOB top (i.e., the merchantable bole.) See appendix J for details on biomass 

equations. 

 The average proportion of aboveground biomass in stem bark is calculated 

using this equation: 

 bark_ratio = Exp(JENKINS_STEM_BARK_RATIO_B1 + 

JENKINS_STEM_BARK_RATIO_B2 / (DIA*2.54)) 

Species category JENKINS_STEM_BARK_RATIO_B1 

Softwood (S) -2.0980 

Hardwood (H) -2.0129 

 43. JENKINS_STEM_BARK_RATIO_B2 

 Jenkins stem bark ratio B2. A coefficient used in computing component ratio 

biomass. This is equivalent to coefficient B1 for stem bark from table 6 in 

Jenkins and others (2003). The appropriate coefficient to use is based on the 

species category (SFTWD_HRDWD). This ratio estimates bark biomass on 

the stem, defined as that portion of the tree from a 1-foot stump to a 4-inch 

DOB top (i.e., the merchantable bole.) See appendix J for details on biomass 

equations. 

 The average proportion of aboveground biomass in stem bark is calculated 

using this equation: 

 bark_ratio = Exp(JENKINS_STEM_BARK_RATIO_B1 + 

JENKINS_STEM_BARK_RATIO_B2 / (DIA*2.54)) 

Species category JENKINS_STEM_BARK_RATIO_B2 

Softwood (S) -1.1432 

Hardwood (H) -1.6805 

 44. JENKINS_FOLIAGE_RATIO_B1 

 Jenkins foliage ratio B1. A coefficient used in computing component ratio 

biomass. This is equivalent to coefficient B0 for foliage from table 6 in 

Jenkins and others (2003). The appropriate coefficient to use is based on the 

species category (SFTWD_HRDWD). See appendix J for details on biomass 

equations. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 179

 The average proportion of aboveground biomass in foliage is calculated using 

this equation: 

 foliage_ratio = Exp(JENKINS_FOLIAGE_RATIO_B1 + 

JENKINS_FOLIAGE_RATIO_B2 / (DIA*2.54)) 

Species category JENKINS_FOLIAGE_RATIO_B1 

Softwood (S) -2.9584 

Hardwood (H) -4.0813 

 45. JENKINS_FOLIAGE_RATIO_B2 

 Jenkins foliage ratio B2. A coefficient used in computing component ratio 

biomass. This is equivalent to coefficient B1 for foliage from table 6 in 

Jenkins and others (2003). The appropriate coefficient to use is based on the 

species category (SFTWD_HRDWD). See appendix J for details on biomass 

equations. 

 The average proportion of aboveground biomass in foliage is calculated using 

this equation: 

 foliage_ratio = Exp(JENKINS_FOLIAGE_RATIO_B1 + 

JENKINS_FOLIAGE_RATIO_B2 / (DIA*2.54)). 

Species category JENKINS_FOLIAGE_RATIO_B2 

Softwood (S) 4.4766 

Hardwood (H) 5.8816 

 46. JENKINS_ROOT_RATIO_B1 

 Jenkins root ratio B1. A coefficient used in computing component ratio 

biomass. This is equivalent to coefficient B0 for coarse roots from table 6 in 

Jenkins and others (2003). The appropriate coefficient to use is based on the 

species category (SFTWD_HRDWD). See appendix J for details on biomass 

equations. 

 The average proportion of coarse roots to total aboveground biomass is 

calculated using this equation: 

 root_ratio = Exp(JENKINS_ROOT_RATIO_B1 + 

JENKINS_ROOT_RATIO_B2 / (DIA*2.54)) 

Species category JENKINS_ROOT_RATIO_B1 

Softwood (S) -1.5619 

Hardwood (H) -1.6911 

 47. JENKINS_ROOT_RATIO_B2 

 Jenkins root ratio B2. A coefficient used in computing component ratio 

biomass. This is equivalent to coefficient B1 for coarse roots from table 6 in 

Jenkins and others (2003). The appropriate coefficient to use is based on the 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Reference Species Table 

180 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

species category (SFTWD_HRDWD). See appendix J for details on biomass 

equations. 

 The average proportion of coarse roots to total aboveground biomass is 

calculated using this equation: 

 root_ratio = Exp(JENKINS_ROOT_RATIO_B1 + 

JENKINS_ROOT_RATIO_B2 / (DIA*2.54)) 

Species category JENKINS_ROOT_RATIO_B2 

Softwood (S) 0.6614 

Hardwood (H) 0.8160 

 48. JENKINS_SAPLING_ADJUSTMENT 

Jenkins sapling adjustment factor. A factor used to compute the biomass of 

saplings. Sapling biomass is computed by multiplying diameter (DIA) by the 

appropriate species adjustment factor (from Jenkins and others [2003]). The 

sapling adjustment factor was computed as a national average ratio of the 

REGIONAL_DRYBIOT (total dry biomass) divided by the Jenkins total 

biomass for all 5.0-inch trees, which is the size at which biomass based on 

volume begins. Because this adjustment factor was computed at the species 

level, there is a specific adjustment factor for each species. Users can 

download the REF_SPECIES table, which includes the values of 

JENKINS_SAPLING_ADJUSTMENT at http://ncrs2.fs.fed.us/fiadb4-

downloads/datamart.html. See appendix J for details on biomass equations. 

 49. WOOD_SPGR_GREENVOL_DRYWT 

 Green specific gravity of wood (green volume and oven-dry weight). This 

variable is used to determine the oven-dry weight (in pounds) of live and 

dead trees based on volume variables in the TREE table (VOLCFSND, 

VOLCFGRS, VOLCFNET...). These volumes are assumed to be green wood 

volumes. Oven-dry biomass for the sound volume in a tree can be calculated 

using this equation: 

 Bodw = VOLCFSND x WOOD_SPGR_GREENVOL_DRYWT x 62.4 

 Where: 

 Bodw = sound oven-dry biomass of a tree in pounds 

 VOLCFSND = sound volume of a tree in cubic feet 

 50. WOOD_SPGR_GREENVOL_DRYWT_CIT 

 Citation for WOOD_SPGR_GREENVOL_DRYWT. The value of this 

variable can be linked to the corresponding value in the CITATION_NBR 

variable in the REF_CITATION table to find the source of the 

WOOD_SPGR_GREENVOL_DRYWT variable. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 181

 51. BARK_SPGR_GREENVOL_DRYWT 

 Green specific gravity of the bark (green volume and oven-dry weight). 

There is some shrinkage in bark volume when a live tree is cut and dried. In 

FIADB, this specific gravity is used on live and dead trees to convert green 

volume to oven-dry weight in pounds. Oven-dry biomass for bark can be 

calculated using the volume of a tree using this equation: 

 Bodw = BARK_VOLUME x BARK_SPGR_GREENVOL_DRYWT x 62.4 

 Where: 

 Bodw = oven-dry biomass of bark on a tree in pounds 

 BARK_VOLUME = volume of the bark on a tree bole, in cubic feet. Note 

that bark volume is often estimated by subtracting volume of the bole inside 

bark from volume of the bole outside bark. Or, an estimate of bark volume 

can be obtained using any tree volume column along with BARK_VOL_PCT 

found in this table as follows: 

 BARK_VOLUME = TREE_VOLUME * (BARK_VOL_PCT/100.0) 

 52. BARK_SPGR_GREENVOL_DRYWT_CIT 

 Citation for BARK_SPGR_GREENVOL_DRYWT. The value of this 

variable can be linked to the corresponding value in the CITATION_NBR 

variable in the REF_CITATION table to find the source of the 

BARK_SPGR_GREENVOL_DRYWT variable. 

 53. MC_PCT_GREEN_WOOD 

 Moisture content of green wood as a percent of oven-dry weight. Wood and 

bark are often sold based on green weight. The user is cautioned that green 

weights can be extremely variable geographically, seasonally, within species 

and across various portions of individual trees. 

 54. MC_PCT_GREEN_WOOD_CIT 

 Citation for MC_PCT_GREEN_WOOD_CIT. The value of this variable can 

be linked to the corresponding value in the CITATION_NBR variable in the 

REF_CITATION table to find the source of the MC_PT_GREEN_WOOD 

variable. 

 55. MC_PCT_GREEN_BARK 

 Moisture content of green bark as a percent of oven-dry weight. Wood and 

bark are often sold based on green weight. The user is cautioned that green 

weights can be extremely variable geographically, seasonally, within species 

and across various portions of individual trees. 
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Chapter 3. Reference Species Table 

182 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 56. MC_PCT_GREEN_BARK_CIT 

 Citation for MC_PCT_GREEN_BARK. The value of this variable can be 

linked to the corresponding value in the CITATION_NBR variable in the 

REF_CITATION table to find the source of the MC_PCT_GREEN_BARK 

variable. 

 57. WOOD_SPGR_MC12VOL_DRYWT 

 Wood specific gravity (12 percent moisture content volume and oven-dry 

weight). Used in biomass estimation of forest products (lumber, veneer, etc.) 

 58. WOOD_SPGR_MC12VOL_DRYWT_CIT 

 Citation for WOOD_SPGR_MC12VOL_DRYWT. The value of this variable 

can be linked to the corresponding value in the CITATION_NBR variable in 

the REF_CITATION table to find the source of the 

WOOD_SPGR_MC12VOL_DRYWT variable. 

 59. BARK_VOL_PCT 

 Bark volume as a percent of wood volume. Bark volume expressed as a 

percent of wood volume. The volume of bark does not include voids due to 

ridges and valleys in bark. 

 60. BARK_VOL_PCT_CIT 

 Citation for BARK_VOL_PCT. The value of this variable can be linked to 

the corresponding value in the CITATION_NBR variable in the 

REF_CITATION table to find the source of the BARK_VOL_PCT variable. 

 61. RAILE_STUMP_DOB_B1 

 Raile stump diameter outside bark equation coefficient B1. This is equivalent 

to coefficient Bfrom table 1 in Raile (1982). See appendix J for details on 

biomass equations. 

 This coefficient is used in an equation to estimate diameter outside bark at 

any point on the stump from ground to 1 foot high. From this, volume outside 

bark is estimated for the selected height along the stump. Volume inside bark 

is subtracted from volume outside bark to estimate bark volume. Both 

volumes are converted to biomass using either wood or bark specific 

gravities. (DOB and DIA are in inches, HT is in feet.) 

 DOB = DIA + (DIA * RAILE_STUMP_DOB_B1 * (4.5-HT) / (HT+1)) 
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Chapter 3. Reference Species Table 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 183

 62. RAILE_STUMP_DIB_B1 

 Raile stump diameter inside bark equation coefficient B1. This is equivalent 

to coefficient A from table 2 in Raile (1982). See appendix J for details on 

biomass equations. 

 This coefficient is used along with RAILE_STUMP_DIB_B2 in an equation 

to estimate diameter inside bark at any point on the stump from ground to 1 

foot high. From this, volume inside bark is estimated for the selected height 

along the stump. Volume inside bark is subtracted from volume outside bark 

to estimate bark volume. Both volumes are converted to biomass using either 

wood or bark specific gravities. (DIB and DIA are in inches, HT is in feet.) 

 DIB = (DIA * RAILE_STUMP_DIB_B1) + 

 (DIA * RAILE_STUMP_DIB_B2 * (4.5-HT) / (HT+1)) 

 63. RAILE_STUMP_DIB_B2 

 Raile stump diameter inside bark equation coefficient B2. This is equivalent 

to coefficient Bfrom table 2 in Raile (1982). See appendix J for details on 

biomass equations. 

 This coefficient is used along with RAILE_STUMP_DIB_B1 in an equation 

to estimate diameter inside bark at any point on the stump from ground to 1 

foot high. From this, volume inside bark is estimated for the selected height 

along the stump. Volume inside bark is subtracted from volume outside bark 

to estimate bark volume. Both volumes are converted to biomass using either 

wood or bark specific gravities. (DIB and DIA are in inches, HT is in feet.) 

 DIB = (DIA * RAILE_STUMP_DIB_B1) + 

 (DIA * RAILE_STUMP_DIB_B2 * (4.5-HT) / (HT+1)) 
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Chapter 3. Reference Species Group Table 

184 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Reference Species Group Table (Oracle table name is REF_SPECIES_GROUP) 

 Column name Descriptive name Oracle data type 

1 SPGRPCD Species group code NUMBER(2) 

2 NAME Name VARCHAR2(35) 

3 REGION Region VARCHAR2(8) 

4 CLASS Class VARCHAR2(8) 

5 CREATED_BY Created by VARCHAR2(30) 

6 CREATED_DATE Created date DATE 

7 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

8 MODIFIED_BY Modified by VARCHAR2(30) 

9 MODIFIED_DATE Modified date DATE 

10 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (SPGRPCD) N/A SGP_PK 

 1. SPGRPCD Species group code. A code assigned to each tree species in order to group 

them for reporting purposes on presentation tables. Codes and their 

associated names (NAME) are shown in appendix G. Individual tree species 

and corresponding species group codes are shown in appendix F. 

 2. NAME Name. A descriptive name for each species group code (SPGRPCD). The 

names associated with these codes are used to label rows or columns in 

national standard presentation tables. 

 3. REGION Region. A description of the section of the United States in which the 

species, and therefore species group is commonly found. Values are 

‘EASTERN’ and ‘WESTERN.’ 

 4. CLASS Class. A descriptor for the classification of the species type with the species 

group. Values are ‘SOFTWOOD’ and ‘HARDWOOD.’ 

 5. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 6. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 7. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 
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Chapter 3. Reference Species Group Table 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 185

 8. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 9. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 10. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 
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Chapter 3. Reference Habitat Type Description Table 

186 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Reference Habitat Type Description Table (Oracle table name is 

REF_HABTYP_DESCRIPTION) 

 Column name Descriptive name Oracle data type 

1 CN Sequence number VARCHAR2(34) 

2 HABTYPCD Habitat type code VARCHAR2(10) 

3 PUB_CD Publication code VARCHAR2(10) 

4 SCIENTIFIC_NAME Scientific name VARCHAR2(115) 

5 COMMON_NAME Common name VARCHAR2(255) 

6 VALID Valid VARCHAR2(1) 

7 CREATED_BY Created by VARCHAR2(30) 

8 CREATED_DATE Created date DATE 

9 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

10 MODIFIED_BY Modified by VARCHAR2(30) 

11 MODIFIED_DATE Modified date DATE 

12 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (CN) N/A RHN_PK 

Unique (HABTYPCD, 

PUB_CD) 

N/A RHN_UK 

Foreign (PUB_CD) REF_HABTYP_DESCRIPTION to 

REF_HABTYP_PUBLICATION 

RHN_RPN_FK 

 1. CN Sequence number. A unique sequence number used to identify a habitat type 

description record. 

 2. HABTYPCD Habitat type code. A code representing a habitat type. Unique codes are 

determined by combining both habitat type code and publication code 

(HABTYPCD and PUB_CD). 

 3. PUB_CD Publication code. A code indicating the publication that lists the name 

associated with a particular habitat type code (HABTYPCD). 

 4. SCIENTIFIC_NAME 

 Scientific name. This attribute contains some type of descriptor, usually the 

Latin name, of the plant(s) associated with the habitat type code. It has values 

such as the entire scientific name or the shortened synonym of the plant(s) 

represented by the habitat type code or it may have an English geographic 

type of descriptor. 

 5. COMMON_NAME 

 Common name. This attribute contains some type of descriptor, usually the 

common name, of the plant(s) associated with the habitat type code. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 187

 6. VALID Valid. A flag to indicate if this is a valid, documented habitat type code. 

Values are Y and N. 

 7. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 8. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 9. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 10. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 11. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 12. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 
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Chapter 3. Reference Habitat Type Publication Table 

188 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Reference Habitat Type Publication Table (Oracle table name is 

REF_HABTYP_PUBLICATION) 

 Column name Descriptive name Oracle data type 

1 CN Sequence number VARCHAR2(34) 

2 PUB_CD Publication code VARCHAR2(10) 

3 TITLE Title of publication VARCHAR2(200) 

4 AUTHOR Author of publication VARCHAR2(200) 

5 TYPE Type of publication VARCHAR2(10) 

6 VALID Valid VARCHAR2(1) 

7 CREATED_BY Created by VARCHAR2(30) 

8 CREATED_DATE Created date DATE 

9 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

10 MODIFIED_BY Modified by VARCHAR2(30) 

11 MODIFIED_DATE Modified date DATE 

12 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (CN) N/A RPN_PK 

Unique (PUB_CD) N/A RPN_UK 

 1. CN Sequence number. A unique sequence number used to identify a habitat type 

publication record. 

 2. PUB_CD Publication code. A code indicating the publication that lists the name 

associated with a particular habitat type code 

(REF_HABTYP_DESCRIPTION.HABTYPCD). 

 3. TITLE Title. The title of the publication defining particular habitat types. 

 4. AUTHOR Author. The author of the publication defining particular habitat types. 

 5. TYPE Type. An attribute describing if the habitat type publication describes 

potential vegetation or existing vegetation. Values are PVREF and EVREF. 

If it is unknown which type of habitat is being described, then TYPE = ?. 

 6. VALID Valid. A flag to indicate if this publication is valid for FIA. Values are Y and 

N. 

 7. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 8. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Reference Habitat Type Publication Table 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 189

 9. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 10. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 11. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 12. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 
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Chapter 3. Reference CitationTable 

190 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Reference Citation Table (Oracle table name is REF_CITATION) 

 Column name Descriptive name Oracle data type 

1 CITATION_NBR Citation number NUMBER(7) 

2 CITATION Citation VARCHAR2(2000) 

3 CREATED_BY Created by VARCHAR2(30) 

4 CREATED_DATE Created date DATE 

5 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

6 MODIFIED_BY Modified by VARCHAR2(30) 

7 MODIFIED_DATE Modified date DATE 

8 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (CITATION_NBR) N/A CIT_PK 

 1. CITATION_NBR 

 Citation number. A unique number used to identify a REF_CITATION 

record. Citation information is currently available in the database only for 

information about the source of specific gravity and bark volume percent 

values contained in the REF_SPECIES table. REF_SPECIES variables 

ending in “_CIT” link back to the REF_CITATION table through 

CITATION_NBR. 

 2. CITATION Citation. This attribute is usually a publication citation. In some cases 

CITATION may contain more specific information about how data were 

populated for a field. 

 3. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 4. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 5. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 
FIA Database Description and Users Manual for Phase 2, version 4.0 

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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 191

 6. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 7. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 8. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Reference Forest Inventory and Analysis Database VersionTable 

192 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Reference Forest Inventory and Analysis Database Version Table (Oracle table name is 

REF_FIADB_VERSION) 

 Column name Descriptive name Oracle data type 

1 VERSION Version number NUMBER(3,1) 

2 DESCR Version description VARCHAR2(2000) 

3 CREATED_BY Created by VARCHAR2(30) 

4 CREATED_DATE Created date DATE 

5 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

6 MODIFIED_BY Modified by VARCHAR2(30) 

7 MODIFIED_DATE Modified date DATE 

8 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

9 INSTALL_TYPE Install type VARCHAR2(10) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (VERSION) N/A RFN_PK 

 1. VERSION Version number. A unique number used to identify a 

REF_FIADB_VERSION record. VERSION equals the currently available 

version of the FIADB. 

 2. DESCR Version description. A description of the FIADB version. This may include a 

literature citation and internet links to documentation. 

 3. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 4. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 5. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 6. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 193

 7. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 8. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 

 9. INSTALL_TYPE 

 Install type. Intentionally left blank. Will be populated in version 5.0. 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

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194 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Reference State Elevation Table (Oracle table name is REF_STATE_ELEV) 

 Column name Descriptive name Oracle data type 

1 STATECD State code NUMBER(4) 

2 MIN_ELEV Minimum elevation NUMBER(5) 

3 MAX_ELEV Maximum elevation NUMBER(5) 

4 LOWEST_POINT Lowest point VARCHAR2(30) 

5 HIGHEST_POINT Highest point VARCHAR2(30) 

6 CREATED_BY Created by VARCHAR2(30) 

7 CREATED_DATE Created date DATE 

8 CREATED_IN_INSTANCE Created in instance VARCHAR26) 

9 MODIFIED_BY Modified by VARCHAR2(30) 

10 MODIFIED_DATE Modified date DATE 

11 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (STATECD) N/A RSE_PK 

 1. STATECD State code. Bureau of the Census Federal Information Processing Standards 

(FIPS) two-digit code for each State. Refer to appendix C. 

 2. MIN_ELEV Minimum elevation. The minimum elevation within the State in feet. 

 3. MAX_ELEV Maximum elevation. The maximum elevation within the State in feet. 

 4. LOWEST_POINT 

 Lowest point. The name of the lowest point within the State. ‘SL’ refers to 

sea level. Negative minimum elevations are listed here. 

 5. HIGHEST_POINT 

 Highest point. The name of the highest point within the State. Alternative 

names are provided also. 

 6. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 7. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 195

 8. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 9. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 

 10. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 11. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 
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Chapter 3. Reference Unit Table 

196 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Reference Unit Table (Oracle table name is REF_UNIT) 

 Column name Descriptive name Oracle data type 

1 STATECD State code NUMBER(4) 

2 VALUE Value NUMBER(2) 

3 MEANING Meaning VARCHAR2(80) 

4 CREATED_BY Created by VARCHAR2(30) 

5 CREATED_DATE Created date DATE 

6 CREATED_IN_INSTANCE Created in instance VARCHAR2(6) 

7 MODIFIED_BY Modified by VARCHAR2(30) 

8 MODIFIED_DATE Modified date DATE 

9 MODIFIED_IN_INSTANCE Modified in instance VARCHAR2(6) 

Type of key Column(s) order Tables to link Abbreviated notation 

Primary (STATECD, VALUE) N/A UNT_PK 

 1. STATECD State code. Bureau of the Census Federal Information Processing Standards 

(FIPS) two-digit code for each State. Refer to appendix C. 

 2. VALUE Value. Forest Inventory and Analysis survey unit identification number. 

Survey units are usually groups of counties within each State. For periodic 

inventories, survey units may be made up of lands of particular owners. Refer 

to appendix C for codes. 

 3. MEANING Meaning. The name corresponding to the survey unit code (VALUE) in the 

State (STATECD). Refer to appendix C. 

 4. CREATED_BY Created by. The employee who created the record. This attribute is 

intentionally left blank in download files. 

 5. CREATED_DATE 

 Created date. The date the record was created. Date will be in the form DDMON-YYYY. 

 6. CREATED_IN_INSTANCE 

 Created in instance. The database instance in which the record was created. 

Each computer system has a unique database instance code and this attribute 

stores that information to determine on which computer the record was 

created. 

 7. MODIFIED_BY 

 Modified by. The employee who modified the record. This field will be blank 

(null) if the data have not been modified since initial creation. This attribute 

is intentionally left blank in download files. 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 3. Reference Unit Table 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 197

 8. MODIFIED_DATE 

 Modified date. The date the record was last modified. This field will be blank 

(null) if the data have not been modified since initial creation. Date will be in 

the form DD-MON-YYYY. 

 9. MODIFIED_IN_INSTANCE 

 Modified in instance. The database instance in which the record was 

modified. This field will be blank (null) if the data have not been modified 

since initial creation. 
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198 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Chapter 4 – Calculating Population Estimates and Their Associated Sampling Errors 

This chapter presents procedures written in OracleTM SQL script that can be used to obtain 

population estimates (and associated sampling errors) for standard FIA attributes from the 

measurement data stored in the FIADB. These estimates follow the equations presented in Bechtold 

and Patterson (2005, chapter 4). Population estimates for many attributes can be generated using 

either the web-based EVALIDator tool or the Forest Inventory Data Online (FIDO) tool, which 

provides interactive access to the FIADB. These tools can be found at http://fia.fs.fed.us/tools-data. 

All data stored in FIADB can be downloaded from http://fia.fs.fed.us/tools-data as either comma 

delimited files or Microsoft (MS) Access databases. Because of size limitations, data are stored in 

individual State databases. The SQL scripts used with MS Access differ from OracleTM SQL scripts 

described in this chapter; however a number of MS Access queries are provided in the MS Access 

databases. All of the FIADB 4.0 tables are included in both formats. The MS Access databases 

have a few additional tables that make using the data and constructing queries easier and simpler. In 

addition, numerous queries that produce population estimates and standard errors are provided. 

Users can use these queries as a starting point to create customized queries suitable for local or 

regional analyses. 

The FIADB can be used to estimate many attributes (e.g., forest area, timberland area, number of 

trees, net volume, biomass) from many different samples (typically State-wide inventories for a 

specific year or set of years). Therefore, the number of estimates that can be made from the FIADB 

is very large, and continues to increase as more data are added to the FIADB. This chapter provides 

examples of a few estimation procedures that can be modified by the user. The resulting estimates 

shown as output are examples only and are not necessarily the exact numbers a user will obtain 

using current data. 

In addition to the naming conventions used in the FIADB, reference is made to the notation and 

terminology used in Bechtold and Patterson (2005). To fully understand the statistical basis of the 

estimation, readers may find it useful to refer to that publication as they review this chapter. 

Examples that estimate area of timberland, number of live trees on forest land, number of seedlings 

on timberland, and volume of growing-stock on timberland are presented, along with discussion of 

how these examples can be modified to estimate other attributes measured in Phase 2. 

The basic estimation is broken down into four steps, with additional steps for users who want to go 

beyond the traditional population level estimates. 

1. Selecting the attribute of interest (the quantity that is to be estimated). 

2. Selecting an appropriate sample. 

3. Linking the appropriate tables in the FIADB to produce estimates for attributes of interest for a 

population. 

4. Producing estimates with sampling errors for attributes of interest for a population. 

5. Restricting the attribute of interest to a smaller subset of the population (e.g., filtering the data 

to include only sawtimber stands on publicly owned timberland, versus all stands in all 

ownerships). 

6. Changing the attribute of interest with user-defined criteria. 

7. Estimating change over time on the standard 4-subplot fixed area plot. 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 199

1. Selecting the attribute of interest (using the REF_POP_ATTRIBUTE table) 

The most common attributes of interest in FIADB estimation are described in the 

REF_POP_ATTRIBUTE table, which currently contains 92 entries. Attributes are currently defined 

at three levels (1) condition level attributes for area estimates; (2) tree level attributes for numbers 

of trees, volume, growth, removals, and mortality estimates; and (3) seedling level attributes for 

number of seedlings estimates. Estimation of condition level attributes requires accessing data on 

the PLOT and COND tables. Estimation of tree level attributes requires accessing data on the 

PLOT, COND, and TREE tables. Estimation of seedling level attributes requires accessing data on 

the PLOT, COND, and SEEDLING tables. Table 4.1 lists the attributes currently defined in the 

REF_POP_ATTRIBUTE table. 

Table 4.1. Values and Descriptions in the REF_POP_ATTRIBUTE table. 

Attribute number 

(ATTRIBUTE_NBR) 

Attribute description 

(ATTRIBUTE_DESCR) 

1 Area sampled and denied access/hazardous (acres) 

2 Area of forestland (acres) 

3 Area of timberland (acres) 

4 Number of all live trees on forestland (trees) 

5 Number of growing-stock trees on forestland (trees) 

6 Number of standing dead trees 5 inches+ dbh on forestland (trees) 

7 Number of all live trees on timberland (trees) 

8 Number of growing-stock trees on timberland (trees) 

9 Number of standing dead trees 5 inches+ dbh on timberland (trees) 

10 All live tree and sapling aboveground biomass on forestland oven-dry (short tons) 

11 All live merchantable biomass on forestland oven-dry (short tons) 

12 All live merchantable biomass on timberland oven-dry (short tons) 

13 All live tree and sapling aboveground biomass on timberland oven-dry (short tons) 

14 Volume of all live on forestland (cuft) 

15 Volume of growing-stock on forestland (cuft) 

16 Volume of sawlog portion on forestland (cuft) 

17 Volume of all live on timberland (cuft) 

18 Volume of growing-stock on timberland (cuft) 

19 Volume of sawlog portion on timberland (cuft) 

20 Volume of sawtimber on forestland (bdft) 

21 Volume of sawtimber on timberland (bdft) 

22 All live gross sawtimber volume on forestland (bdft) 

23 All live gross volume on forestland (cuft) 

24 All live sound volume on forestland (cuft) 

25 Net growth of all live on forestland (cuft per year) 

26 Net growth of growing-stock on forestland (cuft per year) 

27 Net growth of sawtimber on forestland (bdft per year) 

28 Net growth of all live on timberland (cuft per year) 

29 Net growth of growing-stock on timberland (cuft per year) 

30 Net growth of sawtimber on timberland (bdft per year) 

31 Mortality of all live on forestland (cuft per year) 

32 Mortality of all live trees on forestland (trees per year) 

33 Mortality of growing-stock on forestland (cuft per year) 

34 Mortality of sawtimber on forestland (bdft per year) 

35 Mortality of all live on timberland (cuft per year) 

36 Mortality of all live trees on timberland (trees per year) 

37 Mortality of growing-stock on timberland (cuft per year) 

38 Mortality of sawtimber on timberland (bdft per year) 

39 Removals of all live on forestland (cuft per year) 
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200 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Attribute number 

(ATTRIBUTE_NBR) 

Attribute description 

(ATTRIBUTE_DESCR) 

40 Removals of growing-stock on forestland (cuft per year) 

41 Removals of sawtimber on forestland (bdft per year) 

42 Removals of all live on timberland (cuft per year) 

43 Removals of growing-stock on timberland (cuft per year) 

44 Removals of sawtimber on timberland (bdft per year) 

45 Number of live seedlings on forestland (seedlings) 

46 Number of live seedlings on timberland (seedlings) 

47 Carbon in standing dead trees on forestland (short tons) 

48 Carbon in understory aboveground on forestland (short tons) 

49 Carbon in understory belowground on forestland (short tons) 

50 Carbon in down dead on forestland (short tons) 

51 Carbon in litter on forestland (short tons) 

52 Soil organic carbon on forestland (short tons) 

53 Carbon in live trees and saplings aboveground on forestland (short tons) 

54 Carbon in live trees and saplings belowground on forestland (short tons) 

55 

Carbon in live trees and saplings above and belowground on forestland (short 

tons) 

56 All live top and limb biomass on forestland oven-dry (short tons) 

57 All live sapling biomass on forestland oven-dry (short tons) 

58 All live stump (ground to 12 inches) biomass on forestland oven-dry (short tons) 

59 

All live belowground tree and sapling and woodland species biomass on 

forestland oven-dry (short tons) 

60 All live woodland species biomass on forestland oven-dry (short tons) 

61 Carbon in standing dead trees on timberland (short tons) 

62 Carbon in understory aboveground on timberland (short tons) 

63 Carbon in understory belowground on timberland (short tons) 

64 Carbon in down dead on timberland (short tons) 

65 Carbon in litter on timberland (short tons) 

66 Soil organic carbon on timberland (short tons) 

67 Carbon in live trees and saplings aboveground on timberland (short tons) 

68 Carbon in live trees belowground on timberland (short tons) 

69 Carbon in live trees above and belowground on timberland (short tons) 

70 All live top and limb biomass on timberland oven-dry (short tons) 

71 All live sapling biomass on timberland oven-dry (short tons) 

72 All live stump (ground to 12 inches) biomass on timberland oven-dry (short tons) 

73 

All live belowground tree and sapling and woodland species biomass on 

timberland oven-dry (short tons) 

74 All live woodland species biomass on timberland oven-dry (short tons) 

75 

Old regional method – All live tree and sapling aboveground biomass on forestland 

oven-dry (short tons) 

76 

Old regional method – All live merchantable biomass on forestland oven-dry (short 

tons) 

77 

Old regional method – All live merchantable biomass on timberland oven-dry 

(short tons) 

78 

Old regional method – All live tree and sapling aboveground biomass on 

timberland oven-dry (short tons) 

79 Area sampled (acres) 

80 Harvest removals of all live on forestland (cuft per year) 

81 Harvest removals of growing-stock on forestland (cuft per year) 

82 Harvest removals of sawtimber on forestland (bdft per year) 

83 Harvest removals of all live on timberland (cuft per year) 

84 Harvest removals of growing-stock on timberland (cuft per year) 

85 Harvest removals of sawtimber on timberland (bdft per year) 

86 Other removals of all live on forestland (cuft per year) 
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Attribute number 

(ATTRIBUTE_NBR) 

Attribute description 

(ATTRIBUTE_DESCR) 

87 Other removals of growing-stock on forestland (cuft per year) 

88 Other removals of sawtimber on forestland (bdft per year) 

89 Other removals of all live on timberland (cuft per year) 

90 Other removals of growing-stock on timberland (cuft per year) 

91 Other removals of sawtimber on timberland (bdft per year) 

92 Volume of standing dead trees on forestland (cuft) 

In this chapter we present examples that estimate: 

• Area of timberland (REF_POP_ATTRIBUTE.ATTRIBUTE_NBR = 3). 

• Number of live trees on forest land (REF_POP_ATTRIBUTE.ATTRIBUTE_NBR = 4). 

• Volume of growing-stock on timberland (REF_POP_ATTRIBUTE.ATTRIBUTE_NBR = 18. 

• Number of live seedlings on timberland (REF_POP_ATTRIBUTE.ATTRIBUTE_NBR = 46). 

These are examples of condition, tree, and seedling level attributes that can be modified to produce 

other estimates of attributes at these levels. For each attribute, the REF_POP_ATTRIBUTE table 

contains a unique ATTRIBUTE_NBR, a description of the attribute (ATTRIBUTE_DESCR), and 

the variables EXPRESSION and WHERE_CLAUSE that are both portions of the SQL statements 

used to produce the estimates of the attribute. Table 4.2 lists these four variables for the four 

examples we are presenting. (Note: in EXPRESSION and WHERE_CLAUSE, ‘c’ stands for 

COND table, ‘t’ stands for TREE table, ‘s’ stands for SEEDLING table, and ‘pet’ stands for 

POP_EVAL_TYP table.) 

Table 4.2. REF_POP_ATTRIBUTE entries for the four examples presented in this chapter. 

ATTRIBUTE 

NBR ATTRIBUTE DESCR EXPRESSION a WHERE CLAUSE 

3 Area of timberland (acres) c.condprop_unadj* 

decode(c.prop_basis,'MACR',pop_stratum.adj_factor_macr, 

pop_stratum.adj_factor_subp) 

and pet.eval_typ=‘EXPCURR’ 

and c.cond_status_cd=1 and 

c.reservcd=0 and c.siteclcd in 

(1,2,3,4,5,6) 

4 Number of all live trees on 

forestland (trees) 

t.tpa_unadj* 

decode(dia,null,adj_factor_subp, 

decode(least(dia,5-0.001),dia,adj_factor_micr, 

decode(least(dia, nvl(macro_breakpoint_dia,9999)-

0.001),dia,adj_factor_subp, 

adj_factor_macr))) 

and pet.eval_typ=‘EXPVOL’ 

and t.plt_cn=c.plt_cn and 

t.condid=c.condid and 

c.cond_status_cd=1 and t.statuscd=1 

and t.dia>=1.0 

18 Volume of growing-stock on 

timberland (cuft) 

t.tpa_unadj* t.volcfnet* 

decode(dia,null,adj_factor_subp, 

decode(least(dia,5-0.001),dia,adj_factor_micr, 

decode(least(dia, nvl(macro_breakpoint_dia,9999)-

0.001),dia,adj_factor_subp, 

adj_factor_macr))) 

and pet.eval_typ='EXPVOL' 

and t.plt_cn=c.plt_cn and 

t.condid=c.condid and 

c.cond_status_cd=1 and c.reservcd=0 

and c.siteclcd in (1,2,3,4,5,6) and 

t.statuscd=1 and t.treeclcd=2 and 

t.dia>=5.0 

46 Number of live seedlings on 

timberland (seedlings) 

s.tpa_unadj*adj_factor_micr and pet.eval_typ=‘EXPVOL’ 

and s.plt_cn=c.plt_cn and 

s.condid=c.condid and 

c.cond_status_cd=1 and c.reservcd=0 

and c.siteclcd in (1,2,3,4,5,6) 

a Note that for Microsoft Access SQL, the decode function is replaced with the IIF function
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202 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

EXPRESSION is multiplied by the expansion factor POP_STRATUM.EXPNS and summed at the 

condition level in the estimation procedure. In the notation used in Bechtold and Patterson (2005), 

this sum is Phid for area estimation (see equation 4.1, page 47) or yhid for the estimation of tree 

attributes (see equation 4.8, page 53). In all cases, EXPRESSION consists of the product of two 

terms, the first term (c.condprop_unadj, t.tpa_unadj, and s.tpa_unadj in our examples) is the 

unadjusted observation of the attribute of interest (on a per acre basis). The second term is the 

appropriate stratum adjustment factor. The stratum adjustment factor is the inverse of the mean 

proportion of the sample plot areas that were within the population. Following the notation of 

Bechtold and Patterson (2005) this adjustment factor is 

mh p

1 (see equation 4.2, page 49). The 

decode statement simply selects the appropriate adjustment factor to be used for the specific 

estimate. Area estimates use either ADJ_FACTOR_MACR (in inventories where area estimates are 

based on the macroplot) or ADJ_FACTOR_SUBP (in inventories where area estimates are based on 

the subplot) for the adjustment. The adjustment of tree- and seedling-level estimates is based on the 

plot on which the tree or seedling was sampled (seedlings and trees <5 inches diameter are sampled 

on the microplot, larger trees are sampled on the subplot or macroplot depending on diameter). 

Common selection criteria used often with FIA data when creating queries include various 

classifications of land and groups of trees as shown below: 

 Identifying land classes (COND table): 

 

Identifying tree characteristics: 

2. Selecting an appropriate sample (using the POP_EVAL_GRP, POP_EVAL, and 

POP_EVAL_TYP tables) 

In order to compute a sample-based population estimate, the appropriate sample and stratification 

must be identified. In FIA estimation, the sample is a set of plots that were selected for the attribute 

of interest that was observed. The stratification consists of an assignment of plots to strata (nonoverlapping areas of a known or estimated size) that in aggregate define the population of interest. 

There is an assignment of plots to every stratum, and all plots are assigned to one, and only one 

stratum, for each evaluation. FIA uses the term “evaluation” to reference the relationship that links 

a set of plots to a set of strata for estimation purposes. Thus, an evaluation is a set of plots defined 

Forest land COND_STATUS_CD = 1 

Timberland COND_STATUS_CD = 1, SITECLCD <7, RESERVCD = 0 

Nonforest land COND_STATUS_CD = 2 

Reserved forest land COND_STATUS_CD = 1, RESERVCD = 1 

Unreserved forest land COND_STATUS_CD = 1, RESERVCD = 0 

Productive forest land COND_STATUS_CD = 1, SITECLCD <7 

Unproductive forest land COND_STATUS_CD = 1, SITECLCD = 7 

Live trees TREE.STATUSCD = 1 

Standing dead trees TREE.STATUSCD = 2, TREE.STANDING_DEAD_CD = 1 

Growing-stock trees TREE.STATUSCD = 1, TREE.TREECLCD = 2 

Growing-stock volume TREE.STATUSCD = 1, TREE.TREECLCD = 2, TREE.DIA ≥5.0 
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USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 203

in the FIADB that can be used to make a statistically valid sample-based estimate for a population 

(area of land) based on a specific stratification. 

Each evaluation used by FIA is identified, named, and stored as a single entry in the POP_EVAL 

table. The important data items in the POP_EVAL table are listed in table 4.3 for all evaluations 

that are loaded into the FIADB for data collected in Minnesota through 2006. CN is the control 

number that uniquely identifies the entry and is used in creating links to other tables. RSCD 

(Region or Station Code) and EVALID (Evaluation Identifier) are the natural identifiers of a 

specific record. EVAL_DESCR provides a description of the evaluation. STATECD and 

LOCATION_NM describe the geographic extent of the population that was sampled and 

REPORT_YEAR_NM describes the years in which the sample was taken. For older periodic 

inventories, REPORT_YEAR_NM typically reflects a single reporting year (the one used in the 

FIA publications), even though the plots may have been measured over several years. Annual 

inventories (taken since 1999) list the years of data measurements used in the estimation. There are 

usually multiple evaluations for a specific year because not all plots observed have every attribute 

of interest, and/or different stratifications are used in the estimation of different attributes of 

interest. For example, volume estimation can be done on plots measured at only one point in time. 

However, growth estimates require repeat measurements. Thus, evaluations for the estimation of 

growth only assign those plots that are repeat measurement plots to strata, and do not include onetime measurement plots. 

Table 4.3. Important POP_EVAL entries for Minnesota through 2006 from the FIADB. 

Data item names 

CN RSCD EVALID EVAL DESCR STATECD LOCATION NM REPORT YEAR NM 

Data 

item 

values 

107106457010661 23 277701 Minnesota, 1977: area (periodic) 27 Minnesota 1977 

107106458010661 23 277702 Minnesota, 1977: volume (periodic) 27 Minnesota 1977 

107106459010661 23 277703 Minnesota, 1977: growth (periodic) 27 Minnesota 1977 

107106460010661 23 277704 Minnesota, 1977: mortality (periodic) 27 Minnesota 1977 

107106461010661 23 277705 Minnesota, 1977: removals (periodic) 27 Minnesota 1977 

107106462010661 23 279001 Minnesota, 1990: area (periodic) 27 Minnesota 1990 

107106463010661 23 279002 Minnesota, 1990: volume (periodic) 27 Minnesota 1990 

107106464010661 23 279003 Minnesota, 1990: growth (periodic) 27 Minnesota 1990 

107106465010661 23 279004 Minnesota, 1990: mortality (periodic) 27 Minnesota 1990 

107106466010661 23 279005 Minnesota, 1990: removals (periodic) 27 Minnesota 1990 

107106467010661 23 279006 Minnesota, 1990: change (periodic) 27 Minnesota 1990 

107106444010661 23 270300 Minnesota, 1999-2003: all land 27 Minnesota 

1999;2000;2001; 

2002;2003 

107106445010661 23 270301 Minnesota, 1999-2003: area/volume 27 Minnesota 

1999;2000;2001; 

2002;2003 

107106446010661 23 270302 Minnesota, 1990 to 1999-2003: GRM 27 Minnesota 

1999;2000;2001; 

2002;2003 

107106448010661 23 270400 Minnesota, 2000-2004: all land 27 Minnesota 

2000;2001;2002; 

2003;2004 

107106449010661 23 270401 Minnesota, 2000-2004: area/volume 27 Minnesota 

2000;2001;2002; 

2003;2004 

107106450010661 23 270402 Minnesota, 1999 to 2004: GRM 27 Minnesota 2004 

107106451010661 23 270500 Minnesota, 2001-2005: all land 27 Minnesota 

2001;2002;2003; 

2004;2005 

107106452010661 23 270501 Minnesota, 2001-2005: area/volume 27 Minnesota 

2001;2002;2003; 

2004;2005 

107106453010661 23 270502 

Minnesota, 1999-2000 to 2004-2005: 

GRM 27 Minnesota 2004;2005 

107106454010661 23 270600 Minnesota, 2002-2006: all land 27 Minnesota 

2002;2003;2004; 

2005;2006 
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Data item names 

CN RSCD EVALID EVAL DESCR STATECD LOCATION NM REPORT YEAR NM 

107106455010661 23 270601 Minnesota, 2002-2006: area/volume 27 Minnesota 

2002;2003;2004; 

2005;2006 

107106456010661 23 270602 

Minnesota, 1999-2001 to 2004-2006: 

GRM 27 Minnesota 2004;2005;2006 

An evaluation group is the set of evaluations that goes into the contents of a typical FIA report for a 

State. For example the evaluations that went into the report entitled “Minnesota’s forests 1999-2003 

(Part A.)” (Miles and others 2007) are identified by EVALIDs 270300, 270301 and 270302, and are 

collectively identified by a single record in the POP_EVAL_GRP table. Table 4.4 lists the 

important attributes for all evaluation groups that are loaded into FIADB for data collected in 

Minnesota through 2006. 

Table 4.4. Important POP_EVAL_GRP entries for Minnesota through 2006 from the FIADB. 

Data item names Data item values 

CN 107114016010661 107114017010661 107114012010661 107114013010661 107114014010661 107114015010661 

EVAL_CN_FOR_EXPALL 107106444010661 107106448010661 107106451010661 107106454010661 

EVAL_CN_FOR_EXPCURR 107106457010661 107106462010661 107106445010661 107106449010661 107106452010661 107106455010661 

EVAL_CN_FOR_EXPVOL 107106458010661 107106463010661 107106445010661 107106449010661 107106452010661 107106455010661 

EVAL_CN_FOR_EXPGROW 107106459010661 107106464010661 107106446010661 107106450010661 107106453010661 107106456010661 

EVAL_CN_FOR_EXPMORT 107106460010661 107106465010661 107106446010661 107106450010661 107106453010661 107106456010661 

EVAL_CN_FOR_EXPREMV 107106461010661 107106466010661 107106446010661 107106450010661 107106453010661 107106456010661 

RSCD 23 23 23 23 23 23 

EVAL_GRP 271977 271990 272003 272004 272005 272006 

EVAL_GRP_DESCR Minnesota: 1977 Minnesota: 1990 Minnesota: 

1999;2000;2001; 

2002;2003 

Minnesota: 

2000;2001;2002; 

2003;2004 

Minnesota: 

2001;2002;2003; 

2004;2005 

Minnesota: 

2002;2003;2004; 

2005;2006 

In the POP_EVAL_GRP table the data item EVAL_GRP identifies the evaluation group by its State 

code (first 2 digits) and a year (last 4 digits), which is the year commonly associated with estimates 

(if EVAL_GRP does not follow this format, see the EVAL_GRP_DESCR for the precise 

identification). In table 4.4 we see evaluation groups for two periodic inventory estimates (1977 and 

1990), and four annual estimates (2003, 2004, 2005 and 2006). The EVAL_GRP_DESCR describes 

the groups, and indicates that all of the annual inventory estimates are based on 5 years of 

measurements taken over the 5-year period ending with that date. The data items 

EVAL_CN_FOR_EXPALL, EVAL_CN_FOR_EXPCURR, EVAL_CN_FOR_EXPVOL, 

EVAL_CN_FOR_EXPGROW, EVAL_CN_FOR_EXPMORT, and EVAL_CN_FOR_EXPREMV 

identify the evaluations in POP_EVAL that are appropriate for the estimation of various attributes 

of interest. EVAL_CN_FOR_EXPCURR identifies the evaluation used in the estimation of most 

area estimates, such as the area of forestland or the area of timberland. EVAL_CN_FOR_EXPVOL 

identifies the evaluation used in the estimation of tree-level attributes such as number, volume, and 

biomass of trees, and seedling-level estimates, such as number of seedlings. 

EVAL_CN_FOR_EXPGROW, EVAL_CN_FOR_EXPMORT, and EVAL_CN_FOR_EXPREMV 

identify the evaluations used in the estimation of growth, mortality, and removals, respectively. The 

evaluation identified by EVAL_CN_FOR_EXPALL is only appropriate for area estimation where 

the area of hazardous and denied access are of interest. All other evaluations treat hazardous and 

denied access as non-measured and adjust the estimate to account for these areas. 
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The POP_EVAL_TYP table was added to the FIADB in the transition from version 3.0 to 4.0 to 

provide a link between the evaluation groups in POP_EVAL_GRP and the evaluations in 

POP_EVAL. In FIADB 3.0, users could select the appropriate evaluation sequence number 

(EVAL_CN_FOR_xxx) from the POP_EVAL_GRP table. This evaluation sequence number 

allowed them to select the appropriate plots and associated expansions. Evaluations are now also 

identified by the type of evaluation in the value of POP_EVAL_TYP.EVAL_TYP, which can take 

on values of “EXPALL,” “EXPCURR,” “EXPVOL,” “EXPGROW,” “EXPMORT,” or 

“EXPREMV” to identify the type of attributes that can be estimated from a specific evaluation. This 

table allows users to perform similar queries on the appropriate evaluation by identifying only the 

eval_grp (STATECD*10000 + INV_YR) and evaluation type (EVAL_TYP) and allows a variety of 

evaluations to be added in the future. The methods used in version 3.0 will continue to work in 

version 4.0. The examples presented here incorporate the POP_EVAL_TYP as the link from the 

POP_EVAL_GRP to the POP_EVAL table. In the examples below, either of the two joins will 

select the appropriate evaluation for the estimation of area and volume attributes for the Minnesota 

2003 annual inventory. 

FIADB 4.0 example: 

select pev.cn,pev.eval_descr 

from pop_eval_typ pet, pop_eval pev, pop_eval_grp peg 

where peg.eval_grp = 272003 and peg.cn = pet.eval_grp_cn and 

 pev.cn = pet.eval_cn and pet.eval_typ = 'EXPCURR' 

FIADB 3.0 example: 

select pev.cn, pev.eval_descr 

from pop_eval pev, pop_eval_grp peg 

where peg.eval_grp = 272003 and 

 pev.cn = peg.eval_cn_for_expcurr 

3. Linking the appropriate tables in FIADB to produce estimates of attributes of interest for 

a population 

The following OracleTM SQL script can be modified to produce an estimate of any condition-, tree-, 

or seedling-level attribute listed in the REF_POP_ATTRIBUTE table. In this standard script 

(example 4.1), the non-bold text applies to all estimates and the bold text is modified by the user, 

depending on the desired attribute of interest and evaluation group. The line numbers have been 

added for reference. On line 01, the text in the column EXPRESSION in the 

REF_POP_ATTRIBUTE table associated with the desired attribute of interest should be inserted. 

Lines 05 or 06 include either the TREE table or SEEDLING table, and neither line should be 

included for condition level estimates. Line 05 should be included for tree level estimates and line 

06 should be included for seedling level estimates. On line 14, the additions to the SQL where 

clause from the WHERE_CLAUSE column of the REF_POP_ATTRIBUTE table for the desired 

attribute of interest should be inserted. Finally, on line 21, the desired evaluation group needs to be 

indicated by replacing the characters SSYYYY with the desired evaluation group, whereby SS = 

STATECD of the desired State, and YYYY = year of the desired inventory (if EVAL_GRP does 

not follow this format, see the EVAL_GRP_DESCR for the precise identification). With these 

changes, a user can produce the standard estimates for any desired population from the 

REF_POP_ATTRIBUTE table. 
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Estimation requires linking the attribute values (on the COND, TREE, and SEEDLING tables) to 

the stratification information (on the POP_PLOT_STRATUM_ASSGN, POP_STRATUM, and 

POP_ESTN_UNIT) for the selected evaluation that defines the sample. Those links are provided in 

lines 15 thru 20 of the script, and these lines do not change. Line 15 links the 

POP_PLOT_STRATUM_ASSGN record (which contains EXPNS, the plot expansion factor or 

acres assigned to the plot) to the plot record. Line 16 links the POP_PLOT_STRATUM_ASSGN 

record to the POP_STRATUM (which identifies each stratum in the estimation unit). Line 17 links 

the POP_ESTN_UNIT (which identifies each estimation unit in the evaluation) to the POP_ 

STRATUM record. Line 18 links the POP_EVAL, which identifies each evaluation, to the specific 

evaluation that is required for the estimation. Lines 19 and 20 link the appropriate evaluation to the 

attribute and evaluation group for which the estimate is being made. See figure 6 for a schematic of 

links of some of the FIADB tables. 

The following table shows some common aliases or abbreviations used within a SQL script to 

reduce the overall length of the script and improve readability. 

Common aliases for FIADB tables 

p PLOT 

c COND 

t TREE 

s SEEDLING 

ppsa POP_PLOT_STRATUM_ASSGN 

psm POP_STRATUM 

peu POP_ESTN_UNIT 

pet POP_EVAL_TYP 

peg POP_EVAL_GRP 

pev POP_EVAL 

Example 4.1. Standard estimation script 

01 SELECT SUM(psm.expns * EXPRESSION -- insert ref_pop_attribute EXPRESSION here 

02 ) estimate 

03 FROM cond c, 

04 plot p, 

05 tree t, -- tree table must be included for tree level estimates 

06 seedling s, -- seedling table must be included for seedling level estimate

07 pop_plot_stratum_assgn ppsa, 

08 pop_stratum psm, 

09 pop_estn_unit peu, 

10 pop_eval pev, 

11 pop_eval_typ pet, 

12 pop_eval_grp peg 

13 WHERE p.cn = c.plt_cn 

14 WHERE_CLAUSE -- insert ref_pop_attribute WHERE_CLAUSE here 

15 AND ppsa.plt_cn = p.cn 

16 AND ppsa.stratum_cn = psm.cn 

17 AND peu.cn = psm.estn_unit_cn 

18 AND pev.cn = peu.eval_cn 

19 AND pev.cn = pet.eval_cn 

20 AND pet.eval_grp_cn = peg.cn 

21 AND peg.eval_grp = SSYYYY -- the desired evaluation group must be specified
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Figure 6. An abbreviated diagram of select FIADB tables. Note that there are more 

columns in each table than are shown. 
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In the following four examples (4.2, 4.3, 4.4, and 4.5), the scripts are modified from above to 

produce condition, tree, and seedling level estimates for the Minnesota 2003 inventory. Here the 

sections in bold are the sections that changed from the standard estimation script, e.g., the 

REF_POP_ATTRIBUTE.EXPRESSION and REF_POP_ATTRIBUTE.WHERE_CLAUSE have 

been inserted, along with the chosen evaluation number. 

Example 4.2 Estimate area of timberland (acres) 

SELECT SUM(psm.expns * c.condprop_unadj * 

 decode(c.prop_basis, 

 'MACR', 

 psm.adj_factor_macr, 

 psm.adj_factor_subp) -- this is the expression from ref_pop_attribute table 

 ) estimate 

 FROM cond c, 

 plot p, 

 pop_plot_stratum_assgn ppsa, 

 pop_stratum psm, 

 pop_estn_unit peu, 

 pop_eval pev, 

 pop_eval_typ pet, 

 pop_eval_grp peg 

 WHERE p.cn = c.plt_cn 

 AND pet.eval_typ = 'EXPCURR' 

 AND c.cond_status_cd = 1 

 AND c.reservcd = 0 

 AND c.siteclcd IN (1, 2, 3, 4, 5, 6) -- this is the where_clause from ref_pop_attribute table 

 AND ppsa.plt_cn = p.cn 

 AND ppsa.stratum_cn = psm.cn 

 AND peu.cn = psm.estn_unit_cn 

 AND pev.cn = peu.eval_cn 

 AND pev.cn = pet.eval_cn 

 AND pet.eval_grp_cn = peg.cn 

 AND peg.eval_grp = 272003 -- the desired evaluation group must be specified

Produces the following estimate of acres of timberland: 

ESTIMATE 

14,734,137 
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Example 4.3 Estimate number of live trees on forest land (trees) 

 SELECT SUM(psm.expns * t.tpa_unadj * 

 decode(dia, 

 null, 

 adj_factor_subp, 

 decode(least(dia, 5 - 0.001), 

 dia, 

 adj_factor_micr, 

 decode(least(dia, 

 nvl(macro_breakpoint_dia, 9999) - 0.001), 

 dia, 

 adj_factor_subp, 

 adj_factor_macr))) -- this is the expression from ref_pop_attribute table

 ) estimate 

 FROM cond c, 

 plot p, 

 tree t, -- tree table must be included for tree level estimates

 pop_plot_stratum_assgn ppsa, 

 pop_stratum psm, 

 pop_estn_unit peu, 

 pop_eval pev, 

 pop_eval_typ pet, 

 pop_eval_grp peg 

 WHERE p.cn = c.plt_cn 

 AND pet.eval_typ = 'EXPVOL' 

 AND t.plt_cn = c.plt_cn 

 AND t.condid = c.condid 

 AND c.cond_status_cd = 1 

 AND t.statuscd = 1 

 AND t.dia >= 1.0 -- additional where_clause from ref_pop_attribute table

 AND ppsa.plt_cn = p.cn 

 AND ppsa.stratum_cn = psm.cn 

 AND peu.cn = psm.estn_unit_cn 

 AND pev.cn = peu.eval_cn 

 AND pev.cn = pet.eval_cn 

 AND pet.eval_grp_cn = peg.cn 

 AND peg.eval_grp = 272003 -- the desired evaluation group must be specified

Produces the following estimate of total number of live trees on forest land: 

ESTIMATE 

12,078,196,211 
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Example 4.4 Estimate number of live seedlings on timberland (seedlings) 

SELECT SUM(psm.expns * s.tpa_unadj * adj_factor_micr -- expression from ref_pop_attribute table

 ) estimate 

 FROM cond c, 

 plot p, 

 seedling s, -- seedling table must be included for seedling level estimates

 pop_plot_stratum_assgn ppsa, 

 pop_stratum psm, 

 pop_estn_unit peu, 

 pop_eval pev, 

 pop_eval_typ pet, 

 pop_eval_grp peg 

 WHERE p.cn = c.plt_cn 

 AND pet.eval_typ = 'EXPVOL' 

 AND s.plt_cn = c.plt_cn 

 AND s.condid = c.condid 

 AND c.cond_status_cd = 1 

 AND c.reservcd = 0 

 AND c.siteclcd IN (1, 2, 3, 4, 5, 6) -- additional where_clause from ref_pop_attribute table

 AND ppsa.plt_cn = p.cn 

 AND ppsa.stratum_cn = psm.cn 

 AND peu.cn = psm.estn_unit_cn 

 AND pev.cn = peu.eval_cn 

 AND pev.cn = pet.eval_cn 

 AND pet.eval_grp_cn = peg.cn 

 AND peg.eval_grp = 272003 -- the desired evaluation group must be specified

Produces the following estimate of total number of live seedlings on timberland: 

ESTIMATE 

37,141,783,495 
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Example 4.5 Estimate volume of growing-stock on timberland (cubic feet) 

SELECT SUM(psm.expns * t.tpa_unadj * t.volcfnet * 

 decode(dia, 

 null, 

 adj_factor_subp, 

 decode(least(dia, 5 - 0.001), 

 dia, 

 adj_factor_micr, 

 decode(least(dia, 

 nvl(macro_breakpoint_dia, 9999) - 0.001), 

 dia, 

 adj_factor_subp, 

 adj_factor_macr))) -- this is the expression from ref_pop_attribute table

 ) estimate 

 FROM cond c, 

 plot p, 

 tree t, -- tree table must be included for tree level estimates

 pop_plot_stratum_assgn ppsa, 

 pop_stratum psm, 

 pop_estn_unit peu, 

 pop_eval pev, 

 pop_eval_typ pet, 

 pop_eval_grp peg 

 WHERE p.cn = c.plt_cn 

 AND pet.eval_typ = 'EXPVOL' 

 AND t.plt_cn = c.plt_cn 

 AND t.condid = c.condid 

 AND c.cond_status_cd = 1 

 AND c.reservcd = 0 

 AND c.siteclcd in (1, 2, 3, 4, 5, 6) 

 AND t.statuscd = 1 

 AND t.treeclcd = 2 

 AND t.dia >= 5.0 -- additional where_clause from ref_pop_attribute table

 AND ppsa.plt_cn = p.cn 

 AND ppsa.stratum_cn = psm.cn 

 AND peu.cn = psm.estn_unit_cn 

 AND pev.cn = peu.eval_cn 

 AND pev.cn = pet.eval_cn 

 AND pet.eval_grp_cn = peg.cn 

 AND peg.eval_grp = 272003 -- the desired evaluation group must be specified

Produces the following estimate of total growing-stock volume (cubic feet) on timberland: 

ESTIMATE 

15,242,634,295 

Users of the FIADB who wish to produce population estimates should test these four examples to 

be sure they are obtaining identical estimates before proceeding to more complicated estimation. 

Important Note: Users who access data from periodic inventories should restrict the estimation only 

to the standard timberland estimates. In most cases, for periodic inventories, the FIADB contains 

only condition level information on reserved and unproductive forest lands, and tree level 

information on timberland. 
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4. Producing estimates with sampling errors for attributes of interest for a population 

Producing population estimates that include error estimates (sampling error or variance of the 

estimate) along with the estimated total is more complicated. The following OracleTM SQL script 

can be used as a template in producing estimates with sampling errors. The line numbers have been 

added for reference. This example follows the notation used in Bechtold and Patterson (2005, 

equation 4.14 on page 55). Again, the portions of the script that should be changed by the user to 

specify the attribute of interest and population are in bold. Besides returning the estimates and 

sampling errors, this script also outputs the total number of plots in the sample (TOTAL_PLOTS), 

the number of plots where the attribute of interest was observed to occur (NON_ZERO_PLOTS), 

and the total population area (TOTAL_POPULATION_ACRES). This procedure produces two 

intermediate tables: phase_1_summary and phase_2_summary. Phase_1_summary is a stratumlevel table that contains the stratification information necessary in the estimation within strata 

sample sizes (nh), stratum weights (Wh), and population area (AT). Phase_2_summary is a stratumlevel table that contains a summary of the attribute of interest on per-unit-area basis (yhid), including 

the sum and sum of the squared plot-level values and the number of plots where the attribute of 

interest was observed. 

Example 4.6. Standard script for estimates with sampling errors 

01 SELECT eval_grp, 

02 SUM(estimate_by_estn_unit.estimate) estimate, 

03 CASE 

04 WHEN SUM(estimate_by_estn_unit.estimate) > 0 THEN 

05 round(sqrt(SUM(estimate_by_estn_unit.var_of_estimate)) / 

06 SUM(estimate_by_estn_unit.estimate) * 100, 

07 3) 

08 ELSE 

09 0 

10 END AS se_of_estimate_pct, 

11 SUM(estimate_by_estn_unit.var_of_estimate) var_of_estimate, 

12 SUM(estimate_by_estn_unit.total_plots) total_plots, 

13 SUM(estimate_by_estn_unit.non_zero_plots) non_zero_plots, 

14 SUM(estimate_by_estn_unit.total_population_area_acres) total_population_acres 

15 FROM (SELECT pop_eval_grp_cn, 

16 eval_grp, 

17 estn_unit_cn, 

18 SUM(nvl(ysum_hd, 0) * phase_1_summary.expns) estimate, 

19 SUM(phase_1_summary.n_h) total_plots, 

20 SUM(phase_2_summary.number_plots_in_domain) domain_plots, 

21 SUM(phase_2_summary.non_zero_plots) non_zero_plots, 

22 total_area * total_area / SUM(phase_1_summary.n_h) * 

23 ((SUM(w_h * phase_1_summary.n_h * 

24 (((nvl(ysum_hd_sqr, 0) / phase_1_summary.n_h) - 

25 ((nvl(ysum_hd, 0) / phase_1_summary.n_h) * 

26 (nvl(ysum_hd, 0) / phase_1_summary.n_h))) / 

27 (phase_1_summary.n_h - 1)))) + 

28 1 / SUM(phase_1_summary.n_h) * 

29 (SUM((1 - w_h) * phase_1_summary.n_h * 

30 (((nvl(ysum_hd_sqr, 0) / phase_1_summary.n_h) - 

31 ((nvl(ysum_hd, 0) / phase_1_summary.n_h) * 

32 (nvl(ysum_hd, 0) / phase_1_summary.n_h))) / 
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33 (phase_1_summary.n_h - 1))))) var_of_estimate, 

34 total_area total_population_area_acres 

35 FROM (SELECT peg.eval_grp, 

36 peg.cn pop_eval_grp_cn, 

37 psm.estn_unit_cn, 

38 psm.expns, 

39 psm.cn pop_stratum_cn, 

40 p1pointcnt / 

41 (SELECT SUM(strs.p1pointcnt) 

42 FROM pop_stratum strs 

43 WHERE strs.estn_unit_cn = psm.estn_unit_cn) w_h, 

44 (SELECT SUM(strs.p1pointcnt) 

45 FROM pop_stratum strs 

46 WHERE strs.estn_unit_cn = psm.estn_unit_cn) n_prime, 

47 p1pointcnt n_prime_h, 

48 (SELECT SUM(eu_s.area_used) 

49 FROM pop_estn_unit eu_s 

50 WHERE eu_s.cn = psm.estn_unit_cn) total_area, 

51 psm.p2pointcnt n_h 

52 FROM pop_estn_unit peu, 

53 pop_stratum psm, 

54 pop_eval pev, 

55 pop_eval_grp peg, 

56 pop_eval_typ pet 

57 WHERE peu.cn = psm.estn_unit_cn 

58 and pev.cn = peu.eval_cn 

59 and pet.eval_cn = pev.cn 

60 and pet.eval_grp_cn = peg.cn 

61 and pet.eval_typ = 'EXPXXX' -- specify the appropriate expansion

62 AND peg.eval_grp = SSYYYY -- the desired evaluation group must be specified

63 ) phase_1_summary, 

64 (SELECT pop_stratum_cn, 

65 SUM(y_hid_adjusted) ysum_hd, 

66 SUM(y_hid_adjusted * y_hid_adjusted) ysum_hd_sqr, 

67 COUNT(*) number_plots_in_domain, 

68 SUM(decode(y_hid_adjusted, 0, 0, NULL, 0, 1)) non_zero_plots 

69 FROM (SELECT psm.cn pop_stratum_cn, 

70 p.cn plt_cn, 

71 SUM(EXPRESSION) y_hid_adjusted 

 -- the appropriate expression from ref_pop_attribute table

73 FROM cond c, 

74 plot p, 

75 tree t, -- tree table must be included for tree level estimates

76 seedling s, -- seedling table must be included for seedling level estimates

77 pop_plot_stratum_assgn ppsa, 

78 pop_stratum psm, 

79 pop_estn_unit peu, 

80 pop_eval pev, 

81 pop_eval_grp peg, 

82 pop_eval_typ pet 

83 WHERE p.cn = c.plt_cn 

84 WHERE_CLAUSE -- additional where_clause from ref_pop_attribute table 

85 AND ppsa.plt_cn = p.cn 

86 AND ppsa.stratum_cn = psm.cn 

87 AND peu.cn = psm.estn_unit_cn 

88 AND pev.cn = peu.eval_cn 
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89 AND pet.eval_cn = pev.cn 

90 AND pet.eval_grp_cn = peg.cn 

91 AND peg.eval_grp = SSYYYY

 -- the desired evaluation group must be specified 

92 GROUP BY psm.cn, p.cn) 

93 GROUP BY pop_stratum_cn) phase_2_summary 

94 WHERE phase_1_summary.pop_stratum_cn = 

95 phase_2_summary.pop_stratum_cn(+) 

96 GROUP BY pop_eval_grp_cn, 

97 eval_grp, 

98 estn_unit_cn, 

99 phase_1_summary.total_area) estimate_by_estn_unit 

100 GROUP BY pop_eval_grp_cn, eval_grp 

In the following three examples the scripts were modified from above to produce condition, tree, 

and seedling level estimates for the Minnesota 2003 inventory. Here the sections in bold are the 

sections that changed from the standard script for estimates with sampling errors. 

Example 4.7. Estimate Area of timberland (acres) with sampling error. Note the bold sections in this 

example match the bold sections in example 4.2, which estimates the same area without sampling 

errors. 

SELECT eval_grp, 

 SUM(estimate_by_estn_unit.estimate) estimate, 

 CASE 

 WHEN SUM(estimate_by_estn_unit.estimate) > 0 THEN 

 round(sqrt(SUM(estimate_by_estn_unit.var_of_estimate)) / 

 SUM(estimate_by_estn_unit.estimate) * 100, 

 3) 

 ELSE 

 0 

 END AS se_of_estimate_pct, 

 SUM(estimate_by_estn_unit.var_of_estimate) var_of_estimate, 

 SUM(estimate_by_estn_unit.total_plots) total_plots, 

 SUM(estimate_by_estn_unit.non_zero_plots) non_zero_plots, 

 SUM(estimate_by_estn_unit.total_population_area_acres) total_population_acres 

 FROM (SELECT pop_eval_grp_cn, 

 eval_grp, 

 estn_unit_cn, 

 SUM(nvl(ysum_hd, 0) * phase_1_summary.expns) estimate, 

 SUM(phase_1_summary.n_h) total_plots, 

 SUM(phase_2_summary.number_plots_in_domain) domain_plots, 

 SUM(phase_2_summary.non_zero_plots) non_zero_plots, 

 total_area * total_area / SUM(phase_1_summary.n_h) * 

 ((SUM(w_h * phase_1_summary.n_h * 

 (((nvl(ysum_hd_sqr, 0) / phase_1_summary.n_h) - 

 ((nvl(ysum_hd, 0) / phase_1_summary.n_h) * 

 (nvl(ysum_hd, 0) / phase_1_summary.n_h))) / 

 (phase_1_summary.n_h - 1)))) + 

 1 / SUM(phase_1_summary.n_h) * 

 (SUM((1 - w_h) * phase_1_summary.n_h * 

 (((nvl(ysum_hd_sqr, 0) / phase_1_summary.n_h) - 

 ((nvl(ysum_hd, 0) / phase_1_summary.n_h) * 

 (nvl(ysum_hd, 0) / phase_1_summary.n_h))) / 
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 (phase_1_summary.n_h - 1))))) var_of_estimate, 

 total_area total_population_area_acres 

 FROM (SELECT peg.eval_grp, 

 peg.cn pop_eval_grp_cn, 

 psm.estn_unit_cn, 

 psm.cn pop_stratum_cn, 

 psm.expns, 

 p1pointcnt / 

 (SELECT SUM(strs.p1pointcnt) 

 FROM pop_stratum strs 

 WHERE strs.estn_unit_cn = psm.estn_unit_cn) w_h, 

 (SELECT SUM(strs.p1pointcnt) 

 FROM pop_stratum strs 

 WHERE strs.estn_unit_cn = psm.estn_unit_cn) n_prime, 

 p1pointcnt n_prime_h, 

 (SELECT SUM(eu_s.area_used) 

 FROM pop_estn_unit eu_s 

 WHERE eu_s.cn = psm.estn_unit_cn) total_area, 

 psm.p2pointcnt n_h 

 FROM pop_estn_unit peu, 

 pop_stratum psm, 

 pop_eval pev, 

 pop_eval_grp peg, 

 pop_eval_typ pet 

 WHERE peu.cn = psm.estn_unit_cn 

 AND pev.cn = peu.eval_cn 

 AND pet.eval_cn = pev.cn 

 AND pet.eval_grp_cn = peg.cn 

 AND pet.eval_typ = 'EXPCURR' -- specify the appropriate expansion

 AND peg.eval_grp = 272003 -- the desired evaluation group must be specified

 ) phase_1_summary, 

 (SELECT pop_stratum_cn, 

 SUM(y_hid_adjusted) ysum_hd, 

 SUM(y_hid_adjusted * y_hid_adjusted) ysum_hd_sqr, 

 COUNT(*) number_plots_in_domain, 

 SUM(decode(y_hid_adjusted, 0, 0, NULL, 0, 1)) non_zero_plots 

 FROM (SELECT psm.cn pop_stratum_cn, 

 p.cn plt_cn, 

 SUM(c.condprop_unadj * 

 decode(c.prop_basis, 

 'MACR', 

 psm.adj_factor_macr, 

 psm.adj_factor_subp) -- the expression from ref_pop_attribute table

 ) y_hid_adjusted 

 FROM cond c, 

 plot p, 

 pop_plot_stratum_assgn ppsa, 

 pop_stratum psm, 

 pop_estn_unit peu, 

 pop_eval pev, 

 pop_eval_grp peg, 

 pop_eval_typ pet 

 WHERE p.cn = c.plt_cn 

 AND pet.eval_typ = 'EXPCURR' 

 AND c.cond_status_cd = 1 

 AND c.reservcd = 0 

 AND c.siteclcd IN (1, 2, 3, 4, 5, 6)

 -- additional where_clause from ref_pop_attribute table
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 AND ppsa.plt_cn = p.cn 

 AND ppsa.stratum_cn = psm.cn 

 AND peu.cn = psm.estn_unit_cn 

 AND pev.cn = peu.eval_cn 

 AND pet.eval_cn = pev.cn 

 AND pet.eval_grp_cn = peg.cn 

 AND peg.eval_grp = 272003 -- the desired evaluation group must be specified

 GROUP BY psm.cn, p.cn) 

 GROUP BY pop_stratum_cn) phase_2_summary 

 WHERE phase_1_summary.pop_stratum_cn = 

 phase_2_summary.pop_stratum_cn(+) 

 GROUP BY pop_eval_grp_cn, 

 eval_grp, 

 estn_unit_cn, 

 phase_1_summary.total_area) estimate_by_estn_unit 

 GROUP BY pop_eval_grp_cn, eval_grp 

Produces the following estimate of acres of timberland with sampling error: 

EVAL GRP 272003

ESTIMATE 14,734,137

SE OF ESTIMATE PCT 0.7

VAR OF ESTIMATE 10,998,768,175

TOTAL PLOTS 16,041

NON ZERO PLOTS 4,774

TOTAL POPULATION ACRES 54,002,539

Example 4.8. Estimate number of live trees on forest land (trees) with sampling error. Note the bold 

sections in this example match the bold sections in example 4.3, which estimates the same number 

of trees without sampling errors. 

SELECT eval_grp, 

 SUM(estimate_by_estn_unit.estimate) estimate, 

 CASE 

 WHEN SUM(estimate_by_estn_unit.estimate) > 0 THEN 

 round(sqrt(SUM(estimate_by_estn_unit.var_of_estimate)) / 

 SUM(estimate_by_estn_unit.estimate) * 100, 

 3) 

 ELSE 

 0 

 END AS se_of_estimate_pct, 

 SUM(estimate_by_estn_unit.var_of_estimate) var_of_estimate, 

 SUM(estimate_by_estn_unit.total_plots) total_plots, 

 SUM(estimate_by_estn_unit.non_zero_plots) non_zero_plots, 

 SUM(estimate_by_estn_unit.total_population_area_acres) total_population_acres 

 FROM (SELECT pop_eval_grp_cn, 

 eval_grp, 

 estn_unit_cn, 

 sum(nvl(ysum_hd, 0) * phase_1_summary.expns) estimate, 

 SUM(phase_1_summary.n_h) total_plots, 

 SUM(phase_2_summary.number_plots_in_domain) domain_plots, 

 SUM(phase_2_summary.non_zero_plots) non_zero_plots, 

 total_area * total_area / SUM(phase_1_summary.n_h) * 
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 ((SUM(w_h * phase_1_summary.n_h * 

 (((nvl(ysum_hd_sqr, 0) / phase_1_summary.n_h) - 

 ((nvl(ysum_hd, 0) / phase_1_summary.n_h) * 

 (nvl(ysum_hd, 0) / phase_1_summary.n_h))) / 

 (phase_1_summary.n_h - 1)))) + 

 1 / SUM(phase_1_summary.n_h) * 

 (SUM((1 - w_h) * phase_1_summary.n_h * 

 (((nvl(ysum_hd_sqr, 0) / phase_1_summary.n_h) - 

 ((nvl(ysum_hd, 0) / phase_1_summary.n_h) * 

 (nvl(ysum_hd, 0) / phase_1_summary.n_h))) / 

 (phase_1_summary.n_h - 1))))) var_of_estimate, 

 total_area total_population_area_acres 

 FROM (SELECT peg.eval_grp, 

 peg.cn pop_eval_grp_cn, 

 psm.estn_unit_cn, 

 psm.expns, 

 psm.cn pop_stratum_cn, 

 p1pointcnt / 

 (SELECT SUM(strs.p1pointcnt) 

 FROM pop_stratum strs 

 WHERE strs.estn_unit_cn = psm.estn_unit_cn) w_h, 

 (SELECT SUM(strs.p1pointcnt) 

 FROM pop_stratum strs 

 WHERE strs.estn_unit_cn = psm.estn_unit_cn) n_prime, 

 p1pointcnt n_prime_h, 

 (SELECT SUM(eu_s.area_used) 

 FROM pop_estn_unit eu_s 

 WHERE eu_s.cn = psm.estn_unit_cn) total_area, 

 psm.p2pointcnt n_h 

 FROM pop_estn_unit peu, 

 pop_stratum psm, 

 pop_eval pev, 

 pop_eval_grp peg, 

 pop_eval_typ pet 

 WHERE peu.cn = psm.estn_unit_cn 

 AND pev.cn = peu.eval_cn 

 AND pet.eval_cn = pev.cn 

 AND pet.eval_grp_cn = peg.cn 

 AND pet.eval_typ = 'EXPVOL' -- specify the appropriate expansion

 AND peg.eval_grp = 272003 -- the desired evaluation group must be specified

 ) phase_1_summary, 

 (SELECT pop_stratum_cn, 

 SUM(y_hid_adjusted) ysum_hd, 

 SUM(y_hid_adjusted * y_hid_adjusted) ysum_hd_sqr, 

 COUNT(*) number_plots_in_domain, 

 SUM(decode(y_hid_adjusted, 0, 0, NULL, 0, 1)) non_zero_plots 

 FROM (SELECT psm.cn pop_stratum_cn, 

 p.cn plt_cn, 

 SUM(t.tpa_unadj * 

 decode(dia, 

 NULL, 

 adj_factor_subp, 

 decode(least(dia, 5 - 0.001), 

 dia, 

 adj_factor_micr, 

 decode(least(dia, 

 nvl(macro_breakpoint_dia, 

 9999) - 0.001), 
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 dia, 

 adj_factor_subp, 

 adj_factor_macr))) -- expression from ref_pop_attribute table

 ) y_hid_adjusted 

 FROM cond c, 

 plot p, 

 tree t, -- tree table must be included for tree level estimates

 pop_plot_stratum_assgn ppsa, 

 pop_stratum psm, 

 pop_estn_unit peu, 

 pop_eval pev, 

 pop_eval_grp peg, 

 pop_eval_typ pet 

 WHERE p.cn = c.plt_cn 

 AND pet.eval_typ = 'EXPVOL' 

 AND t.plt_cn = c.plt_cn 

 AND t.condid = c.condid 

 AND c.cond_status_cd = 1 

 AND t.statuscd = 1 

 AND t.dia >= 1.0 -- additional where_clause from ref_pop_attribute table

 AND ppsa.plt_cn = p.cn 

 AND ppsa.stratum_cn = psm.cn 

 AND peu.cn = psm.estn_unit_cn 

 AND pev.cn = peu.eval_cn 

 AND pet.eval_cn = pev.cn 

 AND pet.eval_grp_cn = peg.cn 

 AND pev.cn = peg.eval_cn_for_expvol -- specify the appropriate expansion

 AND peg.eval_grp = 272003 -- the desired evaluation group must be specified

 GROUP BY psm.cn, p.cn) 

 GROUP BY pop_stratum_cn) phase_2_summary 

 WHERE phase_1_summary.pop_stratum_cn = 

 phase_2_summary.pop_stratum_cn(+) 

 GROUP BY pop_eval_grp_cn, 

 eval_grp, 

 estn_unit_cn, 

 phase_1_summary.total_area) estimate_by_estn_unit 

 GROUP BY pop_eval_grp_cn, eval_grp 

Produces the following estimate of number of live trees on forest land with sampling error: 

EVAL GRP 272003

ESTIMATE 12,078,196,211

SE OF ESTIMATE PCT 1.3

VAR OF ESTIMATE 25,846,103,844,454,600

TOTAL PLOTS 16,041

NON ZERO PLOTS 5,069

TOTAL POPULATION ACRES 54,002,539
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Example 4.9. Estimate number of seedlings on timberland (seedlings) with sampling error. 

SELECT eval_grp, 

 SUM(estimate_by_estn_unit.estimate) estimate, 

 CASE 

 WHEN SUM(estimate_by_estn_unit.estimate) > 0 THEN 

 round(sqrt(SUM(estimate_by_estn_unit.var_of_estimate)) / 

 SUM(estimate_by_estn_unit.estimate) * 100, 

 3) 

 ELSE 

 0 

 END AS se_of_estimate_pct, 

 SUM(estimate_by_estn_unit.var_of_estimate) var_of_estimate, 

 SUM(estimate_by_estn_unit.total_plots) total_plots, 

 SUM(estimate_by_estn_unit.non_zero_plots) non_zero_plots, 

 SUM(estimate_by_estn_unit.total_population_area_acres) total_population_acres 

 FROM (SELECT pop_eval_grp_cn, 

 eval_grp, 

 estn_unit_cn, 

 sum(nvl(ysum_hd, 0) * phase_1_summary.expns) estimate, 

 SUM(phase_1_summary.n_h) total_plots, 

 SUM(phase_2_summary.number_plots_in_domain) domain_plots, 

 SUM(phase_2_summary.non_zero_plots) non_zero_plots, 

 total_area * total_area / SUM(phase_1_summary.n_h) * 

 ((SUM(w_h * phase_1_summary.n_h * 

 (((nvl(ysum_hd_sqr, 0) / phase_1_summary.n_h) - 

 ((nvl(ysum_hd, 0) / phase_1_summary.n_h) * 

 (nvl(ysum_hd, 0) / phase_1_summary.n_h))) / 

 (phase_1_summary.n_h - 1)))) + 

 1 / SUM(phase_1_summary.n_h) * 

 (SUM((1 - w_h) * phase_1_summary.n_h * 

 (((nvl(ysum_hd_sqr, 0) / phase_1_summary.n_h) - 

 ((nvl(ysum_hd, 0) / phase_1_summary.n_h) * 

 (nvl(ysum_hd, 0) / phase_1_summary.n_h))) / 

 (phase_1_summary.n_h - 1))))) var_of_estimate, 

 total_area total_population_area_acres 

 FROM (SELECT peg.eval_grp, 

 peg.cn pop_eval_grp_cn, 

 psm.estn_unit_cn, 

 psm.expns, 

 psm.cn pop_stratum_cn, 

 p1pointcnt / 

 (SELECT SUM(strs.p1pointcnt) 

 FROM pop_stratum strs 

 WHERE strs.estn_unit_cn = psm.estn_unit_cn) w_h, 

 (SELECT SUM(strs.p1pointcnt) 

 FROM pop_stratum strs 

 WHERE strs.estn_unit_cn = psm.estn_unit_cn) n_prime, 

 p1pointcnt n_prime_h, 

 (SELECT SUM(eu_s.area_used) 

 FROM pop_estn_unit eu_s 

 WHERE eu_s.cn = psm.estn_unit_cn) total_area, 

 psm.p2pointcnt n_h 

 FROM pop_estn_unit peu, 

 pop_stratum psm, 

 pop_eval pev, 

 pop_eval_grp peg, 

 pop_eval_typ pet 
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 WHERE peu.cn = psm.estn_unit_cn 

 AND pev.cn = peu.eval_cn 

 AND pet.eval_cn = pev.cn 

 AND pet.eval_grp_cn = peg.cn 

 AND pet.eval_typ = 'EXPVOL' -- specify the appropriate expansion

 AND peg.eval_grp = 272003 -- the desired evaluation group must be specified

 ) phase_1_summary, 

 (SELECT pop_stratum_cn, 

 SUM(y_hid_adjusted) ysum_hd, 

 SUM(y_hid_adjusted * y_hid_adjusted) ysum_hd_sqr, 

 COUNT(*) number_plots_in_domain, 

 SUM(decode(y_hid_adjusted, 0, 0, NULL, 0, 1)) non_zero_plots 

 FROM (SELECT psm.cn pop_stratum_cn, 

 p.cn plt_cn, 

 SUM(s.tpa_unadj * adj_factor_micr) y_hid_adjusted 

 -- expression from ref_pop_attribute table

 FROM cond c, 

 plot p, 

 seedling s, 

 -- seedling table must be included for seedling level estimates

 pop_plot_stratum_assgn ppsa, 

 pop_stratum psm, 

 pop_estn_unit peu, 

 pop_eval pev, 

 pop_eval_grp peg, 

 pop_eval_typ pet 

 WHERE p.cn = c.plt_cn 

 AND pet.eval_typ = 'EXPVOL' 

 AND s.plt_cn = c.plt_cn 

 AND s.condid = c.condid 

 AND c.cond_status_cd = 1 

 AND c.reservcd = 0 

 AND c.siteclcd IN (1, 2, 3, 4, 5, 6) 

 -- additional where_clause from ref_pop_attribute table

 AND ppsa.plt_cn = p.cn 

 AND ppsa.stratum_cn = psm.cn 

 AND peu.cn = psm.estn_unit_cn 

 AND pev.cn = peu.eval_cn 

 AND pet.eval_cn = pev.cn 

 AND pet.eval_grp_cn = peg.cn 

 AND peg.eval_grp = 272003 -- the desired evaluation group must be specified

 GROUP BY psm.cn, p.cn) 

 GROUP BY pop_stratum_cn) phase_2_summary 

 WHERE phase_1_summary.pop_stratum_cn = 

 phase_2_summary.pop_stratum_cn(+) 

 GROUP BY pop_eval_grp_cn, 

 eval_grp, 

 estn_unit_cn, 

 phase_1_summary.total_area) estimate_by_estn_unit 

 GROUP BY pop_eval_grp_cn, eval_grp 
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Produces the following estimate of number of live seedlings on timberland with sampling error: 

EVAL GRP 272003

ESTIMATE 37,141,783,495

SE OF ESTIMATE PCT 1.8

VAR OF ESTIMATE 455,665,600,805,109,000

TOTAL PLOTS 16,041

NONZERO PLOTS 4,304

TOTAL POPULATION ACRES 54,002,539

5. Restricting the attribute of interest to a smaller subset of the population 

The estimation procedures presented in examples 4.1 through 4.9 can all be modified to restrict the 

estimation to a subset, referred to as the domain of interest. An example of a domain would be only 

sawtimber stands on publicly owned timberland. In effect, the attributes identified in the 

REF_POP_ATTRIBUTE table are a combination of an attribute (e.g., area, number of trees, 

volume, number of seedlings) and a domain (e.g., forest land, timberland, ownership, growing-stock 

trees). The attribute of interest is defined in the REF_POP_ATTRIBUTE.EXPRESSION and the 

domain of interest is defined by REF_POP_ATTRIBUTE.WHERE_CLAUSE. In example 4.2, the 

attribute of interest is area, and the domain of interest is restricted to timberland only. In example 

4.3, the attribute of interest is number of trees, and the domain of interest is restricted to live trees 

on forest land with diameters 1 inch and larger. In example 4.4, the attribute of interest is number of 

seedlings, and the domain of interest is restricted to timberland. In example 4.5, the attribute of 

interest is volume of growing-stock, and the domain of interest is restricted to timberland. 

A word of caution when working with periodic data – not all lands and all attributes were sampled 

in periodic inventories. In some States, only productive, non-reserved lands were sampled in 

periodic inventories. So, applying estimation of number of trees to all forest land in older periodic 

inventories will appear to work, but trees were only measured on timberland, so the estimates will 

only reflect the trees on timberland. Also, in many periodic inventories, seedlings were not tallied. 

In the next example, the domain of interest in example 4.3 is further restricted to a specific species 

(SPCD = 129, eastern white pine), diameter (DIA ≥20, trees 20 inches and larger), and ownership 

(OWNGRPCD = 40, private owners only). The boxed lines have been added to the procedure. The 

procedure now provides an estimate of the total number of live eastern white pine, 20 inches and 

larger on privately owned forest land. 
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Example 4.10 Estimate number of live eastern white pine trees 20 inches and larger on privately 

owned forest land (trees). 

SELECT SUM(psm.expns * t.tpa_unadj * 

 decode(dia, 

 NULL, 

 adj_factor_subp, 

 decode(least(dia, 5 - 0.001), 

 dia, 

 adj_factor_micr, 

 decode(least(dia, 

 nvl(macro_breakpoint_dia, 9999) - 0.001), 

 dia, 

 adj_factor_subp, 

 adj_factor_macr)))) estimate -- expression from ref_pop_attribute table

 FROM cond c, 

 plot p, 

 tree t, -- tree table must be included for tree level estimates

 pop_plot_stratum_assgn ppsa, 

 pop_stratum psm, 

 pop_estn_unit peu, 

 pop_eval pev, 

 pop_eval_grp peg, 

 pop_eval_typ pet 

 WHERE p.cn = c.plt_cn 

 AND pet.eval_typ = 'EXPVOL' 

 AND t.plt_cn = c.plt_cn 

 AND t.condid = c.condid 

 AND c.cond_status_cd = 1 

 AND t.statuscd = 1 

 AND t.dia >= 1.0 -- additional where_clause from ref_pop_attribute table

 AND t.spcd = 129 

 AND t.dia >= 20.0 

 AND c.owngrpcd = 40 -- user-defined additional where_clause 

 AND ppsa.plt_cn = p.cn 

 AND ppsa.stratum_cn = psm.cn 

 AND peu.cn = psm.estn_unit_cn 

 AND pev.cn = peu.eval_cn 

 AND pev.cn = pet.eval_cn 

 AND pet.eval_grp_cn = peg.cn 

 AND peg.eval_grp = 272003 -- the desired evaluation group must be specified 

 

Produces the following estimate of total number of live eastern white pine, 20 inches and larger on 

privately owned forest land: 

ESTIMATE 

519,317 
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Adding the same restrictions to the where clause in example 4.8 provides the following output: 

EVAL GRP 272003

ESTIMATE 519,317

SE OF ESTIMATE PCT 25.1

VAR OF ESTIMATE 17,051,491,226

TOTAL PLOTS 16,041

NON ZERO PLOTS 20

TOTAL POPULATION ACRES 54,002,539

The estimated 519,317 eastern white pine trees, 20 inches and larger on privately owned forest land 

has a sample error of 25.1 percent. Live eastern white pine 20 inches or larger on private forest land 

were observed on a total of 20 plots in the State. 

6. Changing the attribute of interest with user-defined criteria 

Users can define condition level attributes of interest. The standard condition level attributes of 

interest are sampled land area and all land area (expressed in acres). Sampled land area (adjusted for 

denied access and hazardous conditions that were not sampled) is the one used for nearly all 

standard FIA tables that report area estimates. All land area (where denied access and hazardous are 

considered part of the sample) is only used in estimation that treats denied access (plots on land 

where field crews were unable to obtain the owner’s permission to measure the plot) and hazardous 

(conditions that were deemed too hazardous to measure the plots) as part of the sample attribute of 

interest. Most of the other condition level variables that FIA observes are typically used to 

categorize the condition, and are most often applied as restrictions on the population in defining the 

domain, and do not lend themselves as an attribute of interest. For example, BALIVE (the basal 

area of live trees 1 inch diameter and larger) is mainly used to categorize forest land area rather than 

as an attribute of interest in population level estimation. Users are more interested in knowing how 

many acres of forest land meets some basal area requirement (say between 50 and 100 square feet 

per acre), rather than the total basal area of forest land in a State. 

An example of a user-defined condition level attribute of interest, for which an estimate of a total 

might be of interest, would be total land value (see Example 4.11). Here the user would supply a 

function that assigns value ($ per acre) to forest land, based on attributes in FIADB. As an example, 

we use a very arbitrary function of site index and basal area of live tree – value per acre = 1000 + 

(site index x 3) + (basal area x 4), and limit the domain of interest to only private timberland. 

Modifying example 1 produces the following script and estimate of total value. Since the function is 

a condition level value per acre, it is simply included in the expression as a multiplication factor, 

and the domain restriction (private timberland) is added to the where clause. The sections that have 

been added to example 4.2 are in boxes. The same modifications were added to example 4.7 to 

produce the estimates with sampling errors. 
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Example 4.11 Estimated dollar value of private timberland (user defined function). 

SELECT SUM(psm.expns * c.condprop_unadj * 

 decode(c.prop_basis, 

 'MACR', 

 psm.adj_factor_macr, 

 psm.adj_factor_subp) -- expression from ref_pop_attribute table

 * (1000 + c.sicond * 3 + c.balive * 4) -- user-defined value function

 ) estimate 

 FROM cond c, 

 plot p, 

 pop_plot_stratum_assgn ppsa, 

 pop_stratum psm, 

 pop_estn_unit peu, 

 pop_eval pev, 

 pop_eval_grp peg, 

 pop_eval_typ pet 

 WHERE p.cn = c.plt_cn 

 AND pet.eval_typ = 'EXPCURR' 

 AND c.cond_status_cd = 1 

 AND c.reservcd = 0 

 AND c.siteclcd IN (1, 2, 3, 4, 5, 6) -- additional where_clause from ref_pop_attribute table 

 AND c.owngrpcd = 40 -- user-defined additional where_clause

 AND ppsa.plt_cn = p.cn 

 AND ppsa.stratum_cn = psm.cn 

 AND peu.cn = psm.estn_unit_cn 

 AND pev.cn = peu.eval_cn 

 AND pev.cn = pet.eval_cn 

 AND pet.eval_grp_cn = peg.cn 

 AND peg.eval_grp = 272003 -- the desired evaluation group must be specified

Produces the following estimate only from above example: 

ESTIMATE 

10,156,384,067 

And the same modification to example 4.7 produces the following estimate with sampling errors: 

EVAL GRP 272003

ESTIMATE 10,156,384,067

SE OF ESTIMATE PCT 1.4

VAR OF ESTIMATE 18,850,461,684,117,200

TOTAL PLOTS 16,041

NON ZERO PLOTS 2,290

TOTAL POPULATION ACRES 54,002,539

Based on this function, the estimated total value of private timberland in the State is 10.1 billion 

dollars. This value function is used only as an example, any type of user defined function that 

assigns quantities, such as value ($ per acre), wildlife population level (animals per acre), 

productivity (yield per acre), or carbon sequestration potential (tons per acre) could be used as long 

as it is a function of data items in the FIADB, and/or data attributes from other sources that can be 

linked to FIA plots.
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7. Estimates of change over time on the standard 4-subplot fixed area plot 

A number of the attributes described in the REF_POP_ATTRIBUTE table are related to change 

over time and are based on computed attributes that utilize data from two points in time from the 

same plot. The attributes identified by values 25-44 (e.g., net growth of all live on forestland 

represented by 25) of REF_POP_ATTRIBUTE.ATTRIBUTE_NBR are the standard growth, 

removals and mortality attributes that FIA presents in its reports. The computation of these values 

as presented in the previous section will provide estimates of these change attributes; however, all 

estimation is done through the observations made and recorded at the second measurement of the 

plot. Users often wish (1) to obtain estimates that reflect changes in attributes over the 

remeasurement of the plot that go beyond these attributes, (2) to classify these standard estimates 

and other estimates by attributes from the previous measurement, or (3) to cross classify them by 

changes in various attributes over time. Examples of these types of estimations are: 

• Breakdowns of change in area over time by past and current land use, forest type, or other 

condition attributes. 

• Number of trees on forest land that changed to nonforest land. 

• Removals of trees on forest land of a specific forest type that changed to a different forest 

type after removals. 

• Mortality of trees that were in a specific diameter range in the previous measurement. 

• Change in the number of seedlings per acre over time for a specific forest type. 

The estimation of these and many other change attributes require properly selecting the appropriate 

set of plots that were measured at both points in time and linking data from these two 

measurements. 

Prior to 1999, FIA used periodic inventories with different plot designs. Since 1999, the new annual 

inventory uses a national standard, 4-subplot fixed area plot design. The change estimation 

procedures described here are applicable to all plots measured at least twice in the annual inventory, 

but may not be appropriate for change estimation between periodic and annual inventories. 

7.1 Selecting an appropriate set of plots (evaluation) for change estimations 

For change estimation, select an evaluation that consists of only remeasured plots, evaluations used 

for growth, removals, and mortality estimation. These growth-removals-mortality (GRM) 

evaluations can be identified by either of the following restrictions in the where clause: 

and pop_eval.cn = pop_eval_grp.eval_cn_for_expgrow, 

or 

and pop_eval_typ.eval_grp_cn = pop_eval_grp.cn 

and pop_eval_typ.eval_typ = ‘EXPGROW’ 

Either of these statements will restrict the sample plots to only those used in the estimation of 

growth: only the set of plots that have been measured at two points in time. In the examples we 

continue linking to evaluations through the POP_EVAL_TYP table (second example). 
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7.2 Linking tree level data to past condition data 

In the following examples, we demonstrate how to produce a tree-level estimate (net growth of all 

live trees on forest land), and then link it to conditions at two points in time (past and current) to 

produce a table that breaks down the estimate by condition-level attributes and the two points in 

time. 

First we begin with the script that produces an estimate of total net growth of all live trees on forest 

land for the 2007 Minnesota inventory. The evaluation used in this estimate (pop_eval.evalid = 

270703) consists of plots measured in 1999, 2000, 2001, and 2002 that were remeasured in 2004, 

2005, 2006, and 2007, respectively. 

Example 4.12 Estimate net growth of all live trees on forest land (cubic feet per year). 

SELECT SUM(psm.expns * t.tpagrow_unadj * fgrowcfal * 

 decode(dia, 

 null, 

 adj_factor_subp, 

 decode(least(dia, 5 - 0.001), 

 dia, 

 adj_factor_micr, 

 decode(least(dia, 

 nvl(macro_breakpoint_dia, 9999) - 0.001), 

 dia, 

 adj_factor_subp, 

 adj_factor_macr)))) estimate -- expression from ref_pop_attribute table

 FROM cond c, 

 plot p, 

 tree t, -- tree table must be included for tree level estimates

 pop_plot_stratum_assgn ppsa, 

 pop_stratum psm, 

 pop_estn_unit peu, 

 pop_eval pev, 

 pop_eval_grp peg, 

 pop_eval_typ pet 

 WHERE p.cn = c.plt_cn 

 AND pet.eval_typ = 'EXPGROW' 

 AND t.plt_cn = c.plt_cn 

 AND t.condid = c.condid -- additional where_clause from ref_pop_attribute table

 AND ppsa.plt_cn = p.cn 

 AND ppsa.stratum_cn = psm.cn 

 AND peu.cn = psm.estn_unit_cn 

 AND pev.cn = peu.eval_cn 

 AND pev.cn = pet.eval_cn 

 AND pet.eval_grp_cn = peg.cn 

 AND peg.eval_grp = 272007 -- the desired evaluation group must be specified

The example above produces the following estimate of total net growth of all live trees on forest 

land: 

427,200,491 cubic feet per year 

We then modified this example to link not only to the condition record at the current (second) 

measurement, but also to the condition record at the previous (first) measurement by using the 

attribute TREE.PREVCOND to link each tree record to its previous condition. We also added a 
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group by clause to produce the estimates broken down by values of the condition level attributes 

COND_STATUS_CD (condition status code) and STDSZCD (stand-size class code) at both points 

in time. This procedure is shown in example 4.13, which was created by adding the bold sections to 

example 4.12. 

Example 4.13 Estimate net growth of all live on forest land (cubic feet per year) by condition status 

and stand size at two points in time. 

SELECT c_past.cond_status_cd past_cond_status_cd, 

 c_past.stdszcd past_stdszcd, 

 c.cond_status_cd current_cond_status_cd, 

 c.stdszcd current_stdszcd,

 SUM(psm.expns * t.tpagrow_unadj * fgrowcfal * 

 decode(dia, 

 null, 

 adj_factor_subp, 

 decode(least(dia, 5 - 0.001), 

 dia, 

 adj_factor_micr, 

 decode(least(dia, 

 nvl(macro_breakpoint_dia, 9999) - 0.001), 

 dia, 

 adj_factor_subp, 

 adj_factor_macr)))) estimate -- expression from ref_pop_attribute table

 FROM cond c, 

 cond c_past, --past condition is added

 plot p, 

 tree t, -- tree table must be included for tree level estimates 

 pop_plot_stratum_assgn ppsa, 

 pop_stratum psm, 

 pop_estn_unit peu, 

 pop_eval pev, 

 pop_eval_grp peg, 

 pop_eval_typ pet 

 WHERE p.cn = c.plt_cn 

 AND pet.eval_typ = 'EXPGROW' 

 AND t.plt_cn = c.plt_cn 

 AND t.condid = c.condid -- additional where_clause from ref_pop_attribute table 

 AND ppsa.plt_cn = p.cn 

 AND ppsa.stratum_cn = psm.cn 

 AND peu.cn = psm.estn_unit_cn 

 AND pev.cn = peu.eval_cn 

 AND pev.cn = pet.eval_cn 

 AND pet.eval_grp_cn = peg.cn 

 AND peg.eval_grp = 272007 -- the desired evaluation group must be specified 

 AND c_past.plt_cn = p.prev_plt_cn 

 -- links to only those conditions at previous measurement of plot 

 AND c_past.condid = t.prevcond -- links trees to their past condition 

 group by c_past.cond_status_cd, 

 c_past.stdszcd, 

 c.cond_status_cd, 

 c.stdszcd 
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Example 4.13 produces the following estimates of total net growth of all live trees on forest land 

broken down by past and current COND_STATUS_CD and STDSZCD values. 

PAST_COND_ 

STATUS_CD 

PAST_ 

STDSZCD 

CURRENT_COND_ 

STATUS_CD 

CURRENT_ 

STDSZCD ESTIMATE 

1 1 1 1 81,494,163.3 

1 1 1 2 -1,056,519.2 

1 1 1 3 -6,077,491.9 

1 1 1 5 -4,520,213.8 

1 1 2 708,394.8 

1 1 5 0.0 

1 2 1 1 24,639,163.2 

1 2 1 2 121,373,610.5 

1 2 1 3 -298,122.7 

1 2 1 5 -1,358,131.3 

1 2 2 -720,502.7 

1 2 3 -41,231.9 

1 3 1 1 4,596,722.9 

1 3 1 2 29,398,997.6 

1 3 1 3 38,089,804.3 

1 3 1 5 78,764.7 

1 3 2 380,739.8 

1 3 3 0.0 

1 3 4 -327,337.8 

1 5 1 1 1,591,344.2 

1 5 1 2 579,855.3 

1 5 1 3 135,054.2 

1 5 1 5 11,488.4 

1 5 2 2,210.0 

1 5 5 0.0 

2 1 1 67,569,968.1 

2 1 2 45,417,363.4 

2 1 3 11,180,894.0 

2 1 5 557,059.5 

2 2 0.0 

3 1 1 4,285,796.0 

3 1 2 1,838,167.0 

3 1 3 1,187,875.3 

4 1 1 5,868,590.9 

4 1 2 212,902.8 

4 1 3 401,112.0 

5 1 1 0.0 
229

The following tabulation of estimated net growth on forest land by condition status code and stand-size class at the two points in time 

can be made from the example 4.13 results. Note that we have added the code labels to the row and column headings, and each cell in 

the tabulation is the appropriate value from example 4.13. 

CURRENT_COND_STATUS_CD 

Total 

1 Forest land 

Total on 

Forest land 

2 Nonforest 

land 

3 

Noncensus 

water 

4 

Census 

water 

5 

Nonsampled CURRENT_STDSZCD PAST_COND_ 

STATUS_CD PAST_STDSZCD 

1 Large 

diameter 

2 Medium 

diameter 

3 Small 

diameter 5 Nonstocked 

1 Forest land 

1 Large diameter 81,494,163.3 -1,056,519.2 -6,077,491.9 -4,520,213.8 69,839,938.4 708,394.8 0.0 70,548,333.2 

2 Medium diameter 24,639,163.2 121,373,610.5 -298,122.7 -1,358,131.3 144,356,519.6 -720,502.7 -41,231.9 143,594,785.1 3 Small diameter 4,596,722.9 29,398,997.6 38,089,804.3 78,764.7 72,164,289.4 380,739.8 0.0 -327,337.8 72,217,691.4 5 Nonstocked 1,591,344.2 579,855.3 135,054.2 11,488.4 2,317,742.0 2,210.0 0.0 2,319,952.0 

Total on forest land 112,321,393.5 150,295,944.1 31,849,243.9 -5,788,092.1 288,678,489.4 370,842.0 -41,231.9 -327,337.8 0.0 288,680,761.7 2 Nonforest land 67,569,968.1 45,417,363.4 11,180,894.0 557,059.5 124,725,284.9 0.0 124,725,284.9 3 Noncensus water 4,285,796.0 1,838,167.0 1,187,875.3 7,311,838.3 7,311,838.3 4 Census water 5,868,590.9 212,902.8 401,112.0 6,482,605.6 6,482,605.6 5 Nonsampled 0.0 0.0 0.0 Total net growth 190,045,748.4 197,764,377.3 44,619,125.1 -5,231,032.6 427,198,218.2 370,842.0 -41,231.9 -327,337.8 0.0 427,200,490.5 

Estimated total net growth of all live trees on forest land broken down by past and current condition status code and stand-size class, 

Minnesota, 2007 (cubic feet per year).

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7.3 The SUBP_COND_CHNG_MTRX (CMX) table 

The SUBP_COND_CHNG_MTRX (CMX) table was added in the FIADB version 4.0 to facilitate 

the tracking of area change for the annual inventory. Under this design, a plot measures area change 

by tracking the movement in condition boundaries within the area of the four subplots. Figure 7 

shows what can happen on a plot when a condition boundary (in this case the edge of a beaver 

pond) moves over time. Beaver activity raised the level of the pond, increasing the pond area and 

converting some of the forest land to water. The same kind of changes can occur from any number 

of human-caused events such as timber harvesting, land clearing or road construction, or natural 

events such as fire, storms, or insect attacks. 

It is important to remember that condition boundaries are not just defined along changes in 

condition status code, but also may occur within forest land. The following tabulation shows how 

the area change information in figure 7 would be recorded in the CMX table 

CMX table data for figure 7 

SUBP SUBPTYP CONDID PREVCOND SUBPTYP_PROP_CHNG 

1 1 1 1 .8000 

1 1 1 2 .2000 

1 2 1 1 1.000 

2 1 1 1 1.000 

2 2 1 1 1.000 

3 1 2 2 1.000 

3 2 2 2 1.000 

4 1 1 2 1.000 

4 2 1 2 1.000 

Previous plot measurement 

condid = 1, cond_status_cd = 3, beaver pond 

condid = 2, cond_status_cd = 1, forest condid = 2, cond_status_cd = 1, forest 

condition 

boundary 

previous 

condition 

boundary 

new 

condition 

boundary 

Current plot measurement 

condid = 1, cond_status_cd = 3, beaver pond 

Subplot 2 subplot 2 

Subplot 1 subplot 1 

subplot 4 subplot 4 subplot 3 subplot 3 

Figure 7. Example plot layout where condition boundaries changed between previous (left panel) and 

current plot measurements (right panel). The solid circles are the subplots and the smaller dashed 

circles are the microplots. 
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The CMX table tracks the change in condition areas for each of the four subplots (SUBPTYP = 1) 

and each of the four microplots (SUBPTYP = 2) on this plot. In inventories where the macroplot is 

used there would also be entries for each macroplot (SUBPTYP = 3). The attribute PROP_BASIS 

in the COND table identifies how area estimation was conducted for each plot, on the basis of either 

the macroplot or the subplot. In this example area estimation (and thus area change estimation) is 

based on the subplot information, not the macroplot. Area estimation is typically based on the 

largest area sampled (macroplot in States where it is measured, otherwise the subplot) and not on 

the microplot. Area and area change estimation based on the microplot is only appropriate with 

another estimate solely collected on the microplot such as number of trees or biomass in trees 

<5 inches diameter at breast height. The examples of change presented here are based on the 

subplot, but could easily be modified to obtain estimates based on the microplots. 

In the example shown in figure 7, the CMX table has two entries where SUBPTYP = 1 and 

SUBP = 1. The first entry indicates that 80 percent of the subplot area was in condition 1 (water) at 

both measurements, and the second entry indicates 20 percent of the subplot area changed from 

forest to water. For the other three subplots and all four microplots, only one record exists, 

indicating that the entire subplot or microplot either stayed in the same condition (subplots and 

microplots 2 and 3) or the entire area changed from one condition to another (subplot and microplot 

4). For this remeasured plot, change based on the four subplots is water to water 45 percent, forest 

to water 30 percent, and forest to forest 25 percent; change based on the four microplots is water to 

water 50 percent, forest to water 25 percent, and forest to forest 25 percent. The following section 

presents SQL script that produces these estimates. 

7.4 Using the CMX table to estimate area change between two measurements 

The estimation of area change over time requires linking past and current conditions through the 

CMX table to determine the portion of plot area that transitioned from conditions observed at time 1 

to those observed at time 2 (methods applicable only between two measurements in the annual 

inventory). As in examples 4.12 and 4.13, select an evaluation that consists of only remeasured 

plots. In the examples that follow, we show how to create area change estimates that go with the net 

growth of all live trees on forest land as obtained from example 4.13. 

We begin by modifying the script that produces the estimate of area of forest land so that it uses the 

net growth evaluation EXPGROW rather than the area evaluation EXPCURR that is standard for 

area estimations. Example 4.14 shows this modification in bold. 
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Example 4.14 Estimate area of forest land (acres) based on the net growth evaluation. 

SELECT SUM(psm.expns * c.condprop_unadj * 

 decode(c.prop_basis, 

 'MACR', 

 psm.adj_factor_macr, 

 psm.adj_factor_subp) -- expression from ref_pop_attribute table

 ) estimate 

 FROM cond c, 

 plot p, 

 pop_plot_stratum_assgn ppsa, 

 pop_stratum psm, 

 pop_estn_unit peu, 

 pop_eval pev, 

 pop_eval_grp peg, 

 pop_eval_typ pet 

 WHERE p.cn = c.plt_cn 

 and pet.eval_typ = 'EXPGROW'

 AND c.cond_status_cd = 1 -- additional where_clause from ref_pop_attribute table

 AND ppsa.plt_cn = p.cn 

 AND ppsa.stratum_cn = psm.cn 

 AND peu.cn = psm.estn_unit_cn 

 AND pev.cn = peu.eval_cn 

 AND pev.cn = pet.eval_cn 

 AND pet.eval_grp_cn = peg.cn 

 AND peg.eval_grp = 272007 -- the desired evaluation group must be specified

The remeasured plots (12,280 plots) associated with EXPGROW produce an area estimate of 

16,962,397.2 acres of forest land versus 16,723,532.5 provided by EXCURR using all plots (17,855 

plots). Both estimates of forest area are valid; however, only the one based on the remeasurement 

sample can be broken down into two points in time. 

To estimate area change over time, the script has been further modified to link past and current 

condition records through the CMX table. This table has entries for every subplot on a remeasured 

plot and stores the proportion of the area of each subplot by the two points in time in the attribute 

CMX.SUBTYP_PROP_CHNG. Example 4.15 shows the script that produces the area change 

estimates that go with the net growth estimates produced in example 4.13. Again, changes and 

additions from example 4.14 are shown in bold. Line numbers are for reference purposes. 
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Example 4.15 Estimate area change (acres) by condition status and stand size at two points in time, 

Minnesota, time 1 from 1999-2002 and time 2 from 2003-2007 

1 SELECT c_past.cond_status_cd past_cond_status_cd, 

2 c_past.stdszcd past_stdszcd, 

3 c.cond_status_cd current_cond_status_cd, 

4 c.stdszcd current_stdszcd,

5 SUM(psm.expns * CMX.subptyp_prop_chng / 4 *

6 decode(c.prop_basis, 

7 'MACR', 

8 psm.adj_factor_macr, 

9 psm.adj_factor_subp) -- expression from ref_pop_attribute table

10 ) estimate, 

11 count(*) COUNT, 

12 SUM(cmx.subptyp_prop_chng / 4) plot_area

13 FROM cond c, 

14 plot p, 

15 pop_plot_stratum_assgn ppsa, 

16 pop_stratum psm, 

17 pop_estn_unit peu, 

18 pop_eval pev, 

19 pop_eval_typ pet, 

20 pop_eval_grp peg, 

21 cond c_past, 

22 subp_cond_chng_mtrx cmx

23 WHERE p.cn = c.plt_cn 

24 AND pet.eval_typ = 'EXPGROW' 

25 AND (c.cond_status_cd = 1 or c_past.cond_status_cd = 1) 

26 AND ppsa.plt_cn = p.cn 

27 AND ppsa.stratum_cn = psm.cn 

28 AND peu.cn = psm.estn_unit_cn 

29 AND pev.cn = peu.eval_cn 

30 AND pev.cn = pet.eval_cn 

31 AND pet.eval_grp_cn = peg.cn 

32 AND peg.eval_grp = 272007 -- the desired evaluation group must be specified

33 AND p.prev_plt_cn = c_past.plt_cn 

34 AND cmx.prev_plt_cn = c_past.plt_cn 

35 AND cmx.prevcond = c_past.condid 

36 AND cmx.condid = c.condid 

37 AND ((cmx.subptyp = 3 and c.prop_basis = 'MACR') or 

38 (cmx.subptyp = 1 and c.prop_basis = 'SUBP')) 

39 group by c_past.cond_status_cd, 

40 c_past.stdszcd, 

41 c.cond_status_cd, 

42 c.stdszcd

Example 4.15 can be used as a template to create almost any cross tabulation of past and current 

area estimates based on a remeasured set of plots. The following changes (bold sections) were made 

to example 4.14 to facilitate the estimation of area change: 

• Line 21 – The table COND with the alias C_PAST was added to the list of tables to be 

joined. This provides the condition level attributes for the past (time 1) measurement of the 

plot. 
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• Line 22 – The table SUBP_COND_CHG_MTRX with the alias CMX was added to the list 

of tables to be joined. This table provides the link between past (time 1) and current (time 2) 

conditions at the subplot level. Each entry in this table defines the portion (0-1) of the 

subplot, microplot or macroplot that was observed in a condition at time 2 and observed in a 

condition at time 1. For a subplot that was entirely in a single condition at both times, there 

will only be one entry for the subplot, with CMX.SUBPTYP_PROP_CHNG = 1.0. For a 

subplot that was mapped to be 40 percent in one condition and 60 percent in another 

condition at both times with no change in boundary, there will be two entries for the subplot, 

one with CMX.SUBPTYP_PROP_CHNG = 0.4 and the other with 

CMX.SUBPTYP_PROP_CHNG = 0.6. For subplots where boundaries have changed, there 

will be entries that account for all the pieces of the subplot area with the total value of 

CMX.SUBPTYP_PROP_CHNG adding to 1.0. 

• Lines 1-4 and 39-42 – As in example 4.13, past and current condition status and stand-size 

class codes (group by c_past.cond_status_cd, c_past.stdszcd, c.cond_status_cd, 

c.stdszcd) were grouped to obtain estimate breakdowns by these attributes. 

• Line 5 – c.condprop_unadj (the total plot condition proportions that are within a specific 

condition) was replaced with cmx.subptyp_prop_chng / 4 (the subplot condition 

proportion divided by the number of subplots in the plot). The division by 4 is required 

because the CMX table tracks area at the subplot level (4 subplots per plot). 

• Line 25 – The restrictions were changed in the where clause from AND c.cond_status_cd = 

1 to AND (c.cond_status_cd = 1 or c_past.cond_status_cd = 1), to select conditions that 

were forest in at least one of the measurements, not just the current measurement. This 

query tracks the area of land that moves in and out of forest, as well as changes in stand-size 

class on land that remains forest. 

• Lines 33-38 – These additions to the where clause provide the proper links to the C_PAST 

and CMX tables that were added to the table list. Line 33 (AND p.prev_plt_cn = 

c_past.plt_cn) matches the past and current condition records to the same plot, and lines 34-

38 provide the other restrictions that link the appropriate conditions at the two 

measurements through the CMX table. Lines 37 and 38 ensure that in inventories where 

area estimates are based on the macroplot observations, the area change estimates are based 

on the macroplot observations, and in all other cases the estimates are based on the subplot 

observations. 

• Lines 11 and 12 – count(*) COUNT and SUM(CMX.subptyp_prop_chng / 4) 

PLOT_AREA provide two additional summary attributes along with the area estimates. 

COUNT is the total number of subplot pieces that is tracked in the estimation. 

PLOT_AREA is the total portion of plots that is tracked in the estimation. 
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Example 4.15 produces the following estimates of total area (ESTIMATE), total number of subplots 

(COUNT), and total portion of plots (PLOT_AREA) broken down by past and current 

COND_STATUS_CD and STDSZCD values, for land that was forest at measurement time 1, 

measurement time 2, or both. 

PAST_COND_ 

STATUS_CD 

PAST_ 

STDSZCD 

CURRENT_ 

STATUS_CD 

CURRENT_ 

STDSZCD ESTIMATE COUNT PLOT_AREA 

1 1 1 1 3,631,160.4 3208 767.8

1 1 1 2 291,277.3 274 63.1

1 1 1 3 390,763.5 360 83.0

1 1 1 5 58,700.4 53 12.0

1 1 2 70,387.0 117 15.2

1 1 3 3,961.3 10 0.8

1 1 4 2,892.6 9 0.6

1 1 5 2,289.7 2 0.5

1 2 1 1 786,401.0 709 167.1

1 2 1 2 4,648,293.5 4160 996.0

1 2 1 3 620,036.7 571 132.4

1 2 1 5 46,356.9 46 10.2

1 2 2 84,928.1 133 18.8

1 2 3 1,990.6 6 0.4

1 2 4 895.2 1 0.2

1 3 1 1 158,110.2 151 32.5

1 3 1 2 648,108.5 604 138.3

1 3 1 3 4,243,065.9 3884 934.6

1 3 1 5 61,623.3 56 13.1

1 3 2 98,616.9 126 21.4

1 3 3 12,348.1 11 2.1

1 3 4 4,707.5 4 1.0

1 5 1 1 16,820.1 18 3.7

1 5 1 2 18,273.1 20 4.2

1 5 1 3 95,244.4 94 21.5

1 5 1 5 61,597.5 59 14.2

1 5 2 55,411.0 53 11.9

1 5 3 549.8 1 0.1

1 5 5 2,814.4 2 0.5

2 1 1 234,236.1 288 50.7

2 1 2 267,173.3 326 59.6

2 1 3 556,373.0 564 126.3

2 1 5 48,463.7 51 11.0

3 1 1 14,427.4 19 3.1

3 1 2 9,767.2 13 2.3

3 1 3 21,966.0 21 4.3

3 1 5 1,225.5 2 0.3

4 1 1 17,585.0 19 4.0

4 1 2 4,149.1 10 0.9

4 1 3 8,858.1 9 2.0

5 1 1 2,339.8 2 0.5
These results are used to produce the following tabulation of estimated change in forest area by condition status code and stand-size 

class at two points in time.

CURRENT_COND_STATUS_CD 

Total 

1 Forest land 

Total 

Forest land 

2 

Nonforest

land 

3 

Noncensus

water 

4 

Census

water 

5 

Nonsampled CURRENT_STDSZCD PAST_COND_ 

STATUS_CD 

PAST_ STDSZCD 

1 Large 

diameter 

2 Medium 

diameter 

3 Small 

diameter 

5 Nonstocked 

1 Forest land 

1 Large diameter 3,631,160.4 291,277.3 390,763.5 58,700.4 4,371,901.6 70,387.0 3,961.3 2,892.6 2,289.7 4,451,432.2 

2 Medium diameter 786,401.0 4,648,293.5 620,036.7 46,356.9 6,101,088.1 84,928.1 1,990.6 895.2 6,188,902.0 3 Small diameter 158,110.2 648,108.5 4,243,065.9 61,623.3 5,110,907.8 98,616.9 12,348.1 4,707.5 5,226,580.4 5 Nonstocked 16,820.1 18,273.1 95,244.4 61,597.5 191,935.1 55,411.0 549.8 2,814.4 250,710.3 

Total forest land 4,592,491.7 5,605,952.3 5,349,110.6 228,278.0 15,775,832.6 309,343.1 18,849.8 8,495.3 5,104.1 16,117,624.8 2 Nonforest land 234,236.1 267,173.3 556,373.0 48,463.7 1,106,246.1 1,106,246.1 3 Noncensus water 14,427.4 9,767.2 21,966.0 1,225.5 47,386.1 47,386.1 4 Census water 17,585.0 4,149.1 8,858.1 30,592.1 30,592.1 5 Nonsampled 2,339.8 2,339.8 2,339.8 Total 4,861,080.0 5,887,041.9 5,936,307.6 277,967.2 16,962,396.8 309,343.1 18,849.8 8,495.3 5,104.1 17,304,189.0 

Estimated forest land area broken down by past and current condition status code and stand-size class, Minnesota, 2007 (acres).

Includes lands classified as forest at either or both measurements. Based on plots first measured in 1999-2002 and remeasured in 

2003-2007. 

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The total current forest land area in the table above (16,962,396.8 acres) matches (within 1 acre) the 

results we obtained in example 4.14 (16,962,397.2 acres). The difference between these two 

estimates is simply the rounding error introduced by storing and computing condition proportions 

for each of the individual subplot sections in cmx.subptyp_prop_chng versus the total condition 

proportion in c.condprop_unadj. The total past forest land area in the tabulation above 

(16,117,624.8 acres) is based on the same remeasured plots and comes close, but does not match the 

2003 estimate of forest land area (16,230,325.3 acres) one obtains when using example 4.14 and 

setting pet.eval_typ='EXPCURR' and pop_eval_grp.eval_grp = 272003. 

The COUNT and PLOT_AREA values provide data users with the number of measurements 

associated with each estimate, giving users some information about the reliability of the estimates. 

For example, conditions that remained as large diameter (COND.STDSZCD equals 1) from time 1 

to time 2 had an area estimate of 3,631,160.4 acres at time 2. From time 1 to time 2, 3,208 subplots 

or portions of subplots maintained their large diameter condition. These subplots or portions of 

subplots represent an area equivalent to 767.8 total plots. The estimates are based on a considerable 

number of observations. In contrast, if one is interested in tracking area of water (either census or 

noncensus water) that converts to or from forest land over time, estimates are based on far fewer 

observed changes. The estimated area that changed from water (COND.COND_STATUS_CD 

equals 3 or 4) to forest (COND.COND_STATUS_CD equals 1) is 77,978.2 acres, and the estimated 

change from forest to water is 27,345.1 acres. The water to forest change is based on observations 

from 93 subplots where at least a portion of the subplot was observed to change from water to 

forest. The total area of this observed change is equal to 16.8 plots. The change from forest to water 

estimate (27,345.1 acres) is based on 42 subplot observations over an area equivalent to 5.2 plots. 

Example 4.16 presents sampling errors for the forest to water area change estimate. This script was 

created from the script presented in example 4.7 with modifications similar to those made in 

example 4.15. The bold sections indicate where changes were made. The addition of the following 

code to the where clause restricts the estimation to conditions that change from forest 

(c_past.cond_status_cd = 1) to water (c.cond_status_cd IN (3,4)): 

AND (c.cond_status_cd IN (3,4) AND c_past.cond_status_cd = 1). 

Further modifications to this example were made to produce estimates and sampling errors for the 

water to forest area change and for areas that remained as large diameter conditions as discussed in 

the previous paragraph. The results are presented in the tabulation that follows example 4.16. Users 

will note that the sampling errors for the estimates of forest to water and water to forest area change 

are quite high (29.2 percent and 18.4 percent, respectively) and the sampling error on conditions 

remaining large diameter is fairly low (2.9 percent). To obtain other area change and sampling error 

estimates, users should modify the where clause and eval_grp. 

Example 4.16. Estimate area change from forest (cond_status_cd equals 1) to water (cond_status_cd 

equals 3 or 4) with sampling error. Based on the Minnesota 2007 remeasurement sample. Note the 

bold sections in this example indicate where changes in code from example 4.7 were made. 

SELECT eval_grp, 

 SUM(estimate_by_estn_unit.estimate) estimate, 

 CASE 

 WHEN SUM(estimate_by_estn_unit.estimate) > 0 THEN 

 round(sqrt(SUM(estimate_by_estn_unit.var_of_estimate)) / 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 4 

238 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 SUM(estimate_by_estn_unit.estimate) * 100, 

 3) 

 ELSE 

 0 

 END AS se_of_estimate_pct, 

 SUM(estimate_by_estn_unit.var_of_estimate) var_of_estimate, 

 SUM(estimate_by_estn_unit.total_plots) total_plots, 

 SUM(estimate_by_estn_unit.non_zero_plots) non_zero_plots, 

 SUM(estimate_by_estn_unit.total_population_area_acres) total_population_acres 

 FROM (SELECT pop_eval_grp_cn, 

 eval_grp, 

 estn_unit_cn, 

 sum(nvl(ysum_hd, 0) * phase_1_summary.expns) estimate, 

 SUM(phase_1_summary.n_h) total_plots, 

 SUM(phase_2_summary.number_plots_in_domain) domain_plots, 

 SUM(phase_2_summary.non_zero_plots) non_zero_plots, 

 total_area * total_area / SUM(phase_1_summary.n_h) * 

 ((SUM(w_h * phase_1_summary.n_h * 

 (((nvl(ysum_hd_sqr, 0) / phase_1_summary.n_h) - 

 ((nvl(ysum_hd, 0) / phase_1_summary.n_h) * 

 (nvl(ysum_hd, 0) / phase_1_summary.n_h))) / 

 (phase_1_summary.n_h - 1)))) + 

 1 / SUM(phase_1_summary.n_h) * 

 (SUM((1 - w_h) * phase_1_summary.n_h * 

 (((nvl(ysum_hd_sqr, 0) / phase_1_summary.n_h) - 

 ((nvl(ysum_hd, 0) / phase_1_summary.n_h) * 

 (nvl(ysum_hd, 0) / phase_1_summary.n_h))) / 

 (phase_1_summary.n_h - 1))))) var_of_estimate, 

 total_area total_population_area_acres 

 FROM (SELECT peg.eval_grp, 

 peg.cn pop_eval_grp_cn, 

 psm.estn_unit_cn, 

 psm.cn pop_stratum_cn, 

 psm.expns, 

 p1pointcnt / 

 (SELECT SUM(strs.p1pointcnt) 

 FROM pop_stratum strs 

 WHERE strs.estn_unit_cn = psm.estn_unit_cn) w_h, 

 (SELECT SUM(strs.p1pointcnt) 

 FROM pop_stratum strs 

 WHERE strs.estn_unit_cn = psm.estn_unit_cn) n_prime, 

 p1pointcnt n_prime_h, 

 (SELECT SUM(eu_s.area_used) 

 FROM pop_estn_unit eu_s 

 WHERE eu_s.cn = psm.estn_unit_cn) total_area, 

 psm.p2pointcnt n_h 

 FROM pop_estn_unit peu, 

 pop_stratum psm, 

 pop_eval pev, 

 pop_eval_grp peg, 

 pop_eval_typ pet 

 WHERE peu.cn = psm.estn_unit_cn 

 AND pev.cn = peu.eval_cn 

 AND pet.eval_cn = pev.cn 

 AND pet.eval_grp_cn = peg.cn 

 AND pet.eval_typ = 'EXPGROW' -- expansion factor tracking change

 AND peg.eval_grp = 272007 -- desired evaluation group must be specified

 ) phase_1_summary, 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 4 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 239

 (SELECT pop_stratum_cn, 

 SUM(y_hid_adjusted) ysum_hd, 

 SUM(y_hid_adjusted * y_hid_adjusted) ysum_hd_sqr, 

 COUNT(*) number_plots_in_domain, 

 SUM(decode(y_hid_adjusted, 0, 0, NULL, 0, 1)) non_zero_plots 

 FROM (SELECT psm.cn pop_stratum_cn, 

 p.cn plt_cn, 

 SUM(cmx.subptyp_prop_chng / 4 * 

 decode(c.prop_basis, 

 'MACR', 

 psm.adj_factor_macr, 

 psm.adj_factor_subp) -- expression for proportion of tracked plots

 ) y_hid_adjusted 

 FROM cond c, 

 plot p, 

 pop_plot_stratum_assgn ppsa, 

 pop_stratum psm, 

 pop_estn_unit peu, 

 pop_eval pev, 

 pop_eval_typ pet, 

 pop_eval_grp peg, 

 cond c_past, 

 subp_cond_chng_mtrx cmx

 WHERE p.cn = c.plt_cn 

 AND pet.eval_typ = 'EXPGROW' 

 AND (c.cond_status_cd IN (3, 4) AND c_past.cond_status_cd = 1)

 -- where clause tracking change

 AND ppsa.plt_cn = p.cn 

 AND ppsa.stratum_cn = psm.cn 

 AND peu.cn = psm.estn_unit_cn 

 AND pev.cn = peu.eval_cn 

 AND pev.cn = pet.eval_cn 

 AND pet.eval_grp_cn = peg.cn 

 AND peg.eval_grp = 272007 -- desired evaluation group must be specified

 AND p.prev_plt_cn = c_past.plt_cn 

 AND cmx.prev_plt_cn = c_past.plt_cn 

 AND cmx.prevcond = c_past.condid 

 AND cmx.condid = c.condid 

 AND ((cmx.subptyp = 3 and c.prop_basis = 'MACR') or 

 (cmx.subptyp = 1 and c.prop_basis = 'SUBP')) 

 -- join past conditions / change matrix table

 GROUP BY psm.cn, p.cn) 

 GROUP BY pop_stratum_cn) phase_2_summary 

 WHERE phase_1_summary.pop_stratum_cn = 

 phase_2_summary.pop_stratum_cn(+) 

 GROUP BY pop_eval_grp_cn, 

 eval_grp, 

 estn_unit_cn, 

 phase_1_summary.total_area) estimate_by_estn_unit 

 GROUP BY pop_eval_grp_cn, eval_grp 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Chapter 4 

240 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Results of Example 4.16: 

Area change estimates and sampling errors based on remeasured plots, Minnesota, 2007. 

Forest to water Water to forest 

Large diameter forest at both 

measurements 

Changes to where 

clause 

AND 

(c.cond_status_cd IN (3,4) 

AND 

c_past.cond_status_cd = 1) 

AND 

(c.cond_status_cd=1 

AND 

c_past.cond_status_cd IN 

(3,4)) 

AND 

(c.cond_status_cd=1 

AND 

c_past.cond_status_cd=1 

AND 

C.STDSZCD = 1 

AND c_past.STDSZCD = 1 ) 

EVAL_GRP 272007 272007 272007 

ESTIMATE 27,345.1 77,978.2 3,631,160.4 

SE_OF_ESTIMATE_PCT 29.2 18.4 2.9 

VAR_OF_ESTIMATE 63,796,853 206,390,712 11,427,498,039 

TOTAL_PLOTS 12,280 12,280 12,280 

NON_ZERO_PLOTS 32 57 1,007 

TOTAL_POPULATION_ 

ACRES 54,008,479 54,008,479 54,008,479 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Literature Cited 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 241

Literature Cited 

Bechtold, W.A.; Patterson, P.L., editors. 2005. The enhanced Forest Inventory and Analysis 

program – national sampling design and estimation procedures. Gen. Tech. Rep. SRS-80. 

Asheville, NC: U.S. Department of Agriculture Forest Service, Southern Research Station. 

85 p. 

Cleland, D.T.; Freeouf, J.A.; Keys, J.E. [and others]. 2007. Ecological subregions: sections and 

subsections for the conterminous United States. GTR-WO-76. Washington, DC: U.S. 

Department of Agriculture, Forest Service. 

Gillespie, A.J.R. 1999. Rationale for a national annual forest inventory program. Journal of 

Forestry. 97: 16-20. 

Hansen, M.H.; Frieswyk, T.; Glover, J.F.; Kelly, J.F. 1992. The eastwide forest inventory data base: 

users manual. Gen. Tech. Rep. NC-151. St. Paul, MN: U.S. Department of Agriculture, 

Forest Service, North Central Forest Experiment Station. 48 p. 

Hanson, E.J.; Azuma, D.L.; Hiserote, B.A. 2002. Site index equations and mean annual increment 

equations for Pacific Northwest Research Station Forest Inventory and Analysis inventories, 

1985-2001. Res. Note. PNW-RN-533. Portland, OR: U.S. Department of Agriculture, Forest 

Service. 24 p. 

Hawksworth, F.G. 1979. The 6-class dwarf mistletoe rating system. Gen. Tech. Rep. RM-48. Fort 

Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and 

Range Experiment Station. 7 p. 

Heath, L.S.; Hansen, M. H.; Smith,J.E. [and others]. 2009. Investigation into calculating tree 

biomass and carbon in the FIADB using a biomass expansion factor approach. In: Forest 

Inventory and Analysis (FIA) Symposium 2008. RMRS-P-56CD. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research Station. 1 CD 

Jenkins, J.C.; Chojnacky, D.C.; Heath, L.S.; Birdsey, R.A. 2003. National scale biomass estimators 

for United States tree species. Forest Science. 49: 12-35. 

Lister, A.; Scott, C.T.; King, S.L. [and others]. 2005. Strategies for preserving owner privacy in the 

national information management system of the USDA Forest Service’s Forest Inventory 

and Analysis unit. In: Proceedings of the 4th annual Forest Inventory and Analysis 

symposium. Gen. Tech. Rep. NC-GTR-252. St. Paul, MN: U.S. Department of Agriculture, 

Forest Service, North Central Research Station: 163-166. 

MacLean, C.D. 1973. Estimating productivity on sites with a low stocking capacity. Res. Paper. 

PNW-RP-152. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific 

Northwest Forest and Range Experiment Station. 18 p. 

MacLean C.D.; Bolsinger, C.L. 1974. Stockability equations for California forest land. Res. Note. 

PNW-RN-233. Portland, OR: U.S. Department of Agriculture, Forest Service. 10 p. 

Miles, P.D; Smith, W.B. 2009. Specific gravity and other properties of wood and bark for 156 tree 

species found in North America. Res. Note. NRS-38. Newtown Square, PA: U.S. 

Department of Agriculture, Forest Service, Northern Research Station. 35 p. 

Miles, P.D.; Brand, G.J.; Alerich, C.L. [and others]. 2001. The forest inventory and analysis 

database: database description and users manual version 1.0. Gen. Tech. Rep. NC-218. St. 

Paul, MN: U.S. Department of Agriculture, Forest Service, North Central Research Station. 

130 p. 

Miles, P.D.; Jacobson, K.; Brand, G.J. [and others]. 2007. Minnesota’s forests 1999-2003 (Part A). 

Reourc. Bull. NRS-12A. Newtown Square, PA: U.S. Department of Agriculture, Forest 

Service, Northern Research Station. 92 p. 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

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National Atlas of the United States. 2007. Congressional Districts of the United States - 110th 

Congress. Reston, VA: National Atlas of the United States. Available online: 

http://nationalatlas.gov/atlasftp.html 

Nowacki, G.; Brock, T. 1995. Ecoregions and subregions of Alaska, EcoMap version 2.0 (map). 

Juneau, AK: U.S. Department of Agriculture, Forest Service, Alaska Region. scale 

1:5,000,000. (http://agdcftp1.wr.usgs.gov/pub/projects/fhm/ecomap.gif) 

Raile, G.K. 1982. Estimating stump volume. Res. Paper. NC-224. St. Paul, MN: U.S. Department of 

Agriculture, Forest Service, North Central Forest Experiment Station. 4 p. 

Scott, C.T.; Cassell, D.L.; Hazard, J.W. 1993. Sampling design of the U.S. National Forest Health 

Program. In: Nyyssonen, A.; Poso, S.; Rautala, J. (eds.), Ilvessalo Symposium on National 

Forest Inventories. Research Parpers 444. [Location unknown]: Finnish Forest Research 

Institute London. p. 150-157. 

Smith, J.E.; Heath, L.S. 2002. A model of forest floor carbon mass for United States forest types. 

Res. Paper. NE-722. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, 

Northeastern Research Station. 37 p. 

Smith, J.E.; Heath, L.S. 2008. Forest sections of the land use change and forestry chapter, and 

Annex. In: US Environmental Protection Agency, Inventory of US Greenhouse Gas 

Emissions and Sinks: 1990-2006. EPA 430-R-08-005. 

http://www.epa.gov/climatechange/emissions/usinventoryreport.htm (17 October). 

Smith, W.B. 2002. Forest inventory and analysis: a national inventory and monitoring program. 

Environmental Pollution. 116 (Suppl. 1): S233-S242. 

U.S. Census Bureau. 1994. The geographic areas reference manual. 

http://www.census.gov/geo/www/garm.html [Date accessed: June 18, 2008]. 

U.S. Department of Agriculture, Forest Service. 2008. Accuracy standards. In: Forest Survey 

Handbook. FSH 4809.11, chapter 10. Washington, DC: U.S. Department of Agriculture, 

Forest Service. [Not paged] 

U.S. Environmental Protection Agency. 2008. Inventory of U.S. greenhouse gas emissions and 

sinks: 1990–2006. EPA 430-R-08-005. Washington, DC: United States Environmental 

Protection Agency, Office of Atmospheric Programs. Available online at 

http://epa.gov/climatechange/emissions/. 

Van Hooser, D.D.; Cost, N.D.; Lund, H.G. 1993. The history of the forest survey program in the 

United States. In: Proceedings of the IUFRO Centennial Meeting. [Location unknown]: 

Japan Society of Forest Planning Press, Tokyo University of Agriculture: 19-27. 

Wilson, H. M. 1900. A Dictionary of Topographic Forms. Journal of the American Geographical 

Society of New York. 32: 32-41. 

Woodall, C.W.; Conkling, B.L.; Amacher, M.C. [and others]. 2010. The Forest Inventory and 

Analysis database version 4.0: database description and users manual for phase 3. Gen. 

Tech. Rep. NRS – 61. Newtown Square, PA: U.S. Department of Agriculture, Forest 

Service, Northern Research Station. 180 p. 

Woudenberg, S.W.; Farrenkopf, T.O. 1995. The Westwide forest inventory data base: user's 

manual. Gen. Tech. Rep. INT-GTR-317. Ogden, UT: U.S. Department of Agriculture, 

Forest Service, Intermountain Research Station. 67 p. 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix A 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 243

Appendix A. Index of Column Names 

The following table lists column names used in the database tables, their location within the table, and a short 

description. 

Column name with (field guide 

section) Table name 

Location 

in table Description 

ACTUALHT (5.15) TREE 22 Actual height of tree 

ADFORCD COND 15 Administrative forest code 

ADJ_FACTOR_MACR POP_STRATUM 12 Adjustment factor for the 

macroplot 

ADJ_FACTOR_MICR POP_STRATUM 14 Adjustment factor for the 

microplot 

ADJ_FACTOR_SUBP POP_STRATUM 13 Adjustment factor for the subplot 

AGEDIA (7.2.5) SITETREE 14 Age at diameter height 

AGENTCD (5.21) TREE 27 Cause of death (agent) code 

ALLOWED_IN_FIELD REF_FOREST_TYPE 6 Allowed in field 

ALSTK COND 53 All-live-tree stocking percent 

ALSTKCD COND 37 All live stocking code 

ANN_INVENTORY SURVEY 8 Annual inventory 

AREA_SOURCE POP_ESTN_UNIT 11 Source of area figures usually 

Census Bureau or from pixel 

counts 

AREA_USED POP_ESTN_UNIT 10 Area used to calculate all 

expansion factors 

AREALAND_EU POP_ESTN_UNIT 8 Land area within the estimation 

unit 

AREATOT_EU POP_ESTN_UNIT 9 Total area within the estimation 

unit 

ASPECT COND 34 Aspect 

ASPECT (3.7) SUBPLOT 17 Subplot aspect 

ATTRIBUTE_DESCR REF_POP_ATTRIBUTE 3 Estimation attribute e.g., Area of 

timberland 

ATTRIBUTE_NBR POP_EVAL_ATTRIBUTE 3 Attribute number 

ATTRIBUTE_NBR REF_POP_ATTRIBUTE 2 Arbitrary unique number 

AUTHOR REF_HABTYP_PUBLICATION 4 Author of publication 

AZIMUTH (7.2.8) SITETREE 19 Azimuth 

AZIMUTH (5.4) TREE 12 Azimuth 

AZMCORN (4.2.6) BOUNDARY 13 Corner azimuth 

AZMLEFT (4.2.5) BOUNDARY 12 Left azimuth 

AZMRIGHT (4.2.8) BOUNDARY 15 Right azimuth 

BALIVE COND 51 Basal area of live trees 

BARK_SPGR_GREENVOL_DRYWT REF_SPECIES 51 Green specific gravity bark (green 

volume and oven-dry weight) 

BARK_SPGR_GREENVOL_DRYWT

_CIT 

REF_SPECIES 52 Green specific gravity bark 

citation 

BARK_VOL_PCT REF_SPECIES 59 Bark volume as a percent of wood 

volume 

BARK_VOL_PCT_CIT REF_SPECIES 60 Bark volume as a percent of wood 

volume citation 

BFSND TREE 73 Board-foot-cull soundness 

BHAGE TREE 66 Breast height age 

BNDCHG (4.2.3) BOUNDARY 10 Boundary change code 

BOLEHT TREE 76 Bole height 

BORED_CD_PNWRS TREE 125 Tree bored code, Pacific 

Northwest Research Station 

CANOPY_CVR_SAMPLE_METHOD

_CD 

COND 97 Canopy cover sample method 

code 

CARBON_AG TREE 121 Carbon aboveground 

CARBON_BG TREE 122 Carbon belowground 

CARBON_DOWN_DEAD COND 67 Carbon in down dead 

CARBON_LITTER COND 68 Carbon in litter 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix A 

244 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Column name with (field guide 

section) Table name 

Location 

in table Description 

CARBON_SOIL_ORG COND 69 Carbon in soil fine organic 

material 

CARBON_STANDING_DEAD COND 70 Carbon in standing dead trees 

CARBON_UNDERSTORY_AG COND 71 Carbon in the aboveground 

portions of seedlings, shrubs, and 

bushes 

CARBON_UNDERSTORY_BG COND 72 Carbon in the belowground 

portion of seedlings, shrubs ,and 

bushes 

CCLCD (5.17) TREE 25 Crown class code 

CDENCD (12.9) TREE 61 Crown density code 

CDIEBKCD (12.10) TREE 62 Crown dieback code 

CFSND TREE 74 Cubic-foot-cull soundness 

CITATION REF_CITATION 2 Citation 

CITATION_NBR REF_CITATION 1 Citation number 

CLASS REF_SPECIES_GROUP 4 Class 

CLIGHTCD (12.6) TREE 59 Crown light exposure code 

CN BOUNDARY 1 Sequence number 

CN COND 1 Sequence number 

CN COUNTY 5 Sequence number 

CN PLOT 1 Sequence number 

CN POP_ESTN_UNIT 1 Sequence number 

CN POP_EVAL 1 Sequence number 

CN POP_EVAL_ATTRIBUTE 1 Sequence number 

CN POP_EVAL_GRP 1 Sequence number 

CN POP_EVAL_TYP 11 Sequence number 

CN POP_PLOT_STRATUM_ ASSGN 1 Sequence number 

CN POP_STRATUM 1 Sequence number 

CN REF_HABTYP_DESCRIPTION 1 Sequence number 

CN REF_HABTYP_PUBLICATION 1 Sequence number 

CN REF_POP_ATTRIBUTE 1 Sequence number 

CN REF_POP_EVAL_TYP_DESCR 9 Sequence number 

CN SEEDLING 1 Sequence number 

CN SITETREE 1 Sequence number 

CN SUBPLOT 1 Sequence number 

CN SUBP_COND 1 Sequence number 

CN SUBP_COND_CHNG_MTRX 1 Sequence number 

CN SURVEY 1 Sequence number 

CN TREE 1 Sequence number 

COMMON_NAME REF_HABTYP_DESCRIPTION 5 Common name 

COMMON_NAME REF_SPECIES 2 Common name of species 

CORE REF_SPECIES 36 Core 

COND_NONSAMPLE_REASN_CD 

(2.4.3) 

COND 10 Condition nonsampled reason 

code 

COND_STATUS_CD (2.4.2) COND 9 Condition status code 

CONDID (2.4.1) COND 8 Condition class number 

CONDID (6.3) SEEDLING 9 Condition class number 

CONDID SITETREE 9 Condition class number 

CONDID SUBP_COND 9 Condition class number 

CONDID SUBP_COND_CHNG_MTRX 6 Condition class number 

CONDID (5.3) TREE 11 Condition class number 

CONDLIST SUBPLOT 15 Subplot/macroplot plot condition 

list 

CONDLIST SITETREE 24 Condition class list 

CONDPROP_UNADJ COND 29 Condition proportion unadjusted 

CONGCD PLOT 28 Congressional district code 

CONTRAST (4.2.4) BOUNDARY 11 Contrasting condition 

COUNTYCD BOUNDARY 6 County code 

COUNTYCD COND 6 County code 

COUNTYCD COUNTY 3 County code 

COUNTYCD (1.2) PLOT 8 County code 
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Appendix A 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 245

Column name with (field guide 

section) Table name 

Location 

in table Description 

COUNTYCD POP_PLOT_STRATUM_ ASSGN 7 County code 

COUNTYCD SEEDLING 6 County code 

COUNTYCD SITETREE 7 County code 

COUNTYCD SUBPLOT 7 County code 

COUNTYCD SUBP_COND 6 County code 

COUNTYCD TREE 7 County code 

COUNTYNM COUNTY 4 County name 

CPOSCD (12.7) TREE 58 Crown position code 

CR (5.19) TREE 24 Compacted crown ratio 

CREATED_BY BOUNDARY 18 Created by 

CREATED_BY COND 73 Created by 

CREATED_BY COUNTY 6 Created by 

CREATED_BY PLOT 33 Created by 

CREATED_BY POP_ESTN_UNIT 14 Created by 

CREATED_BY POP_EVAL 9 Created by 

CREATED_BY POP_EVAL_ATTRIBUTE 5 Created by 

CREATED_BY POP_EVAL_GRP 13 Created by 

CREATED_BY POP_EVAL_TYP 5 Created by 

CREATED_BY POP_PLOT_STRATUM_ ASSGN 13 Created by 

CREATED_BY POP_STRATUM 15 Created by 

CREATED_BY REF_CITATION 3 Created by 

CREATED_BY REF_FIADB_VERSION 3 Created by 

CREATED_BY REF_FOREST_TYPE 7 Created by 

CREATED_BY REF_HABTYP_DESCRIPTION 7 Created by 

CREATED_BY REF_HABTYP_PUBLICATION 7 Created by 

CREATED_BY REF_POP_ATTRIBUTE 6 Created by 

CREATED_BY REF_POP_EVAL_TYP_DESCR 3 Created by 

CREATED_BY REF_SPECIES 30 Created by 

CREATED_BY REF_SPECIES_GROUP 5 Created by 

CREATED_BY REF_STATE_ELEV 6 Created by 

CREATED_BY REF_UNIT 4 Created by 

CREATED_BY SEEDLING 15 Created by 

CREATED_BY SITETREE 25 Created by 

CREATED_BY SUBPLOT 20 Created by 

CREATED_BY SUBP_COND 10 Created by 

CREATED_BY SUBP_COND_CHNG_MTRX 10 Created by 

CREATED_BY SURVEY 10 Created by 

CREATED_BY TREE 81 Created by 

CREATED_BY TREE_REGIONAL_BIOMASS 5 Created by 

CREATED_DATE BOUNDARY 19 Created date 

CREATED_DATE COND 74 Created date 

CREATED_DATE COUNTY 7 Created date 

CREATED_DATE PLOT 34 Created date 

CREATED_DATE POP_ESTN_UNIT 15 Created date 

CREATED_DATE POP_EVAL 10 Created date 

CREATED_DATE POP_EVAL_ATTRIBUTE 6 Created date 

CREATED_DATE POP_EVAL_GRP 14 Created date 

CREATED_DATE POP_EVAL_TYP 6 Created date 

CREATED_DATE POP_PLOT_STRATUM_ ASSGN 14 Created date 

CREATED_DATE POP_STRATUM 16 Created date 

CREATED_DATE REF_CITATION 4 Created date 

CREATED_DATE REF_FIADB_VERSION 4 Created date 

CREATED_DATE REF_FOREST_TYPE 8 Created date 

CREATED_DATE REF_HABTYP_DESCRIPTION 8 Created date 

CREATED_DATE REF_HABTYP_PUBLICATION 8 Created date 

CREATED_DATE REF_POP_ATTRIBUTE 7 Created date 

CREATED_DATE REF_POP_EVAL_TYP_DESCR 4 Created date 

CREATED_DATE REF_SPECIES 31 Created date 

CREATED_DATE REF_SPECIES_GROUP 6 Created date 

CREATED_DATE REF_STATE_ELEV 7 Created date 

CREATED_DATE REF_UNIT 5 Created date 
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Appendix A 

246 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Column name with (field guide 

section) Table name 

Location 

in table Description 

CREATED_DATE SEEDLING 16 Created date 

CREATED_DATE SITETREE 26 Created date 

CREATED_DATE SUBPLOT 21 Created date 

CREATED_DATE SUBP_COND 11 Created date 

CREATED_DATE SUBP_COND_CHNG_MTRX 11 Created date 

CREATED_DATE SURVEY 11 Created date 

CREATED_DATE TREE 82 Created date 

CREATED_DATE TREE_REGIONAL_BIOMASS 6 Created date 

CREATED_IN_INSTANCE BOUNDARY 20 Created in instance 

CREATED_IN_INSTANCE COND 75 Created in instance 

CREATED_IN_INSTANCE COUNTY 8 Created in instance 

CREATED_IN_INSTANCE PLOT 35 Created in instance 

CREATED_IN_INSTANCE POP_ESTN_UNIT 16 Created in instance 

CREATED_IN_INSTANCE POP_EVAL 11 Created in instance 

CREATED_IN_INSTANCE POP_EVAL_ATTRIBUTE 7 Created in instance 

CREATED_IN_INSTANCE POP_EVAL_GRP 15 Created in instance 

CREATED_IN_INSTANCE POP_EVAL_TYP 7 Created in instance 

CREATED_IN_INSTANCE POP_PLOT_STRATUM_ ASSGN 15 Created in instance 

CREATED_IN_INSTANCE POP_STRATUM 17 Created in instance 

CREATED_IN_INSTANCE REF_CITATION 5 Created in instance 

CREATED_IN_INSTANCE REF_FIADB_VERSION 5 Created in instance 

CREATED_IN_INSTANCE REF_FOREST_TYPE 9 Created in instance 

CREATED_IN_INSTANCE REF_HABTYP_DESCRIPTION 9 Created in instance 

CREATED_IN_INSTANCE REF_HABTYP_PUBLICATION 9 Created in instance 

CREATED_IN_INSTANCE REF_POP_ATTRIBUTE 8 Created in instance 

CREATED_IN_INSTANCE REF_POP_EVAL_TYP_DESCR 5 Created in instance 

CREATED_IN_INSTANCE REF_SPECIES 32 Created in instance 

CREATED_IN_INSTANCE REF_SPECIES_GROUP 7 Created in instance 

CREATED_IN_INSTANCE REF_STATE_ELEV 8 Created in instance 

CREATED_IN_INSTANCE REF_UNIT 6 Created in instance 

CREATED_IN_INSTANCE SEEDLING 17 Created in instance 

CREATED_IN_INSTANCE SITETREE 27 Created in instance 

CREATED_IN_INSTANCE SUBPLOT 22 Created in instance 

CREATED_IN_INSTANCE SUBP_COND 12 Created in instance 

CREATED_IN_INSTANCE SUBP_COND_CHNG_MTRX 12 Created in instance 

CREATED_IN_INSTANCE SURVEY 12 Created in instance 

CREATED_IN_INSTANCE TREE 83 Created in instance 

CREATED_IN_INSTANCE TREE_REGIONAL_BIOMASS 7 Created in instance 

CTY_CN PLOT 3 County sequence number 

CULL TREE 28 Rotten and missing cull, 

computed and includes percent 

missing top 

CULL_FLD (5.13) TREE 91 Rotten and missing cull, fieldrecorded 

CULLBF TREE 71 Board-foot cull 

CULLCF TREE 72 Cubic-foot cull 

CULLDEAD TREE 68 Dead cull 

CULLFORM TREE 69 Form cull 

CULLMSTOP TREE 70 Missing top cull 

CVIGORCD (12.8) TREE 60 Sapling vigor code 

CYCLE BOUNDARY 16 Inventory cycle number 

CYCLE COND 79 Inventory cycle number 

CYCLE PLOT 46 Inventory cycle number 

CYCLE SEEDLING 23 Inventory cycle number 

CYCLE SITETREE 31 Inventory cycle number 

CYCLE SUBPLOT 26 Inventory cycle number 

CYCLE SUBP_COND 21 Inventory cycle number 

CYCLE SURVEY 16 Inventory cycle number 

CYCLE TREE 123 Inventory cycle number 

DAMLOC1 (5.20.1) TREE 29 Damage location 1 code 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix A 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 247

Column name with (field guide 

section) Table name 

Location 

in table Description 

DAMLOC1_PNWRS TREE 126 Damage location 1, Pacific 

Northwest Research Station 

DAMLOC2 (5.20.4) TREE 32 Damage location 2 code 

DAMLOC2_PNWRS TREE 127 Damage location 2, Pacific 

Northwest Research Station 

DAMSEV1 (5.20.3) TREE 31 Damage severity 1 code 

DAMSEV2 (5.20.6) TREE 34 Damage severity 2 code 

DAMTYP1 (5.20.2) TREE 30 Damage type 1 code 

DAMTYP2 (5.20.5) TREE 33 Damage type 2 code 

DECAYCD (5.23) TREE 35 Decay class code 

DECLINATION (1.11) PLOT 40 Declination 

DESCR REF_FIADB_VERSION 2 Version description 

DESIGNCD PLOT 17 Plot design code 

DIA (7.2.3) SITETREE 12 Current diameter 

DIA (5.9.2) TREE 18 Current diameter 

DIACALC TREE 65 Current diameter calculated 

DIACHECK (5.12) TREE 54 Diameter check code 

DIACHECK_PNWRS TREE 128 Diameter check, Pacific 

Northwest Research Station 

DIAHTCD TREE 19 Diameter height code 

DIST (7.2.9) SITETREE 20 Horizontal distance 

DIST (5.5) TREE 13 Horizontal distance 

DISTCORN (4.2.7) BOUNDARY 14 Corner distance 

DMG_AGENT1_CD_PNWRS TREE 129 Damage agent 1, Pacific 

Northwest Research Station 

DMG_AGENT2_CD_PNWRS TREE 130 Damage agent 2, Pacific 

Northwest Research Station 

DMG_AGENT3_CD_PNWRS TREE 131 Damage agent 3, Pacific 

Northwest Research Station 

DRYBIO_BG TREE 120 Dry biomass belowground 

DRYBIO_BOLE TREE 115 Dry biomass of bole 

DRYBIO_SAPLING TREE 118 Dry biomass of sapling 

DRYBIO_STUMP TREE 117 Dry biomass of stump 

DRYBIO_TOP TREE 116 Dry biomass of top 

DRYBIO_WDLD_SPP TREE 119 Dry biomass of woodland species 

DSTRBCD1 (2.5.11) COND 38 Disturbance 1 code 

DSTRBCD2 (2.5.13) COND 40 Disturbance 2 code 

DSTRBCD3 (2.5.15) COND 42 Disturbance 3 code 

DSTRBYR1 (2.5.12) COND 39 Year of disturbance 1 

DSTRBYR2 (2.5.14) COND 41 Year of disturbance 2 

DSTRBYR3 (2.5.16) COND 43 Year of disturbance 3 

E_SPGRPCD REF_SPECIES 8 East species group code 

EAST REF_SPECIES 25 East 

ECO_UNIT_PNW PLOT 48 Ecological unit used to identify 

Pacific Northwest Research 

Station stockability algorithms 

ECOSUBCD PLOT 27 Ecological subsection code 

ELEV PLOT 22 Elevation 

EMAP_HEX PLOT 41 EMAP hexagon 

END_INVYR POP_EVAL 16 End inventory year 

ESTN_UNIT POP_ESTN_UNIT 5 Estimation unit 

ESTN_UNIT POP_PLOT_STRATUM_ ASSGN 11 Estimation unit 

ESTN_UNIT POP_STRATUM 5 Estimation unit 

ESTN_UNIT_CN POP_STRATUM 2 Estimation unit sequence number 

ESTN_UNIT_DESCR POP_ESTN_UNIT 6 Estimation unit description 

EVAL_CN POP_ESTN_UNIT 2 Evaluation sequence number 

EVAL_CN POP_EVAL_ATTRIBUTE 2 Evaluation sequence number 

EVAL_CN POP_EVAL_TYP 2 Evaluation sequence number 

EVAL_CN_FOR_EXPALL POP_EVAL_GRP 2 Evaluation sequence number for 

expansions of all plots 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix A 

248 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Column name with (field guide 

section) Table name 

Location 

in table Description 

EVAL_CN_FOR_EXPCURR POP_EVAL_GRP 3 Evaluation sequence number for 

expansions of current area 

EVAL_CN_FOR_EXPGROW POP_EVAL_GRP 5 Evaluation sequence number for 

expansions of growth 

EVAL_CN_FOR_EXPMORT POP_EVAL_GRP 6 Evaluation sequence number for 

expansions of mortality 

EVAL_CN_FOR_EXPREMV POP_EVAL_GRP 7 Evaluation sequence number for 

expansions of removals 

EVAL_CN_FOR_EXPVOL POP_EVAL_GRP 4 Evaluation sequence number for 

expansions of volume 

EVAL_DESCR POP_EVAL 4 Evaluation description 

EVAL_GRP POP_EVAL_GRP 9 Reporting year followed by 4 

more digits to make the 

statecd/eval_grp combo unique 

EVAL_GRP_CN POP_EVAL_TYP 1 Evaluation group sequence 

number 

EVAL_GRP_DESCR POP_EVAL_GRP 10 Evaluation group description 

EVAL_TYP POP_EVAL_TYP 3 Evaluation type 

EVAL_TYP REF_POP_EVAL_TYP_DESCR 1 Evaluation type 

EVAL_TYP_DESCR REF_POP_EVAL_TYP_DESCR 2 Evaluation type description 

EVALID POP_ESTN_UNIT 4 Evaluation identifier 

EVALID POP_EVAL 3 Evaluation identifier 

EVALID POP_PLOT_STRATUM_ ASSGN 10 Evaluation identifier 

EVALID POP_STRATUM 4 Evaluation identifier 

EXISTS_IN_NCRS REF_SPECIES 13 Exists in the North Central 

Research Station States 

EXISTS_IN_NERS REF_SPECIES 14 Exists in the Northeastern 

Research Station States 

EXISTS_IN_PNWRS REF_SPECIES 15 Exists in the Pacific Northwest 

Research Station States 

EXISTS_IN_RMRS REF_SPECIES 16 Exists in the Rocky Mountain 

Research Station States 

EXISTS_IN_SRS REF_SPECIES 17 Exists in the Southern Research 

Station States 

EXPNS POP_STRATUM 11 Expansion factor 

EXPRESSION REF_POP_ATTRIBUTE 4 Part of the expression used to 

produce the estimate 

FGROWBFSL TREE 95 Net annual merchantable boardfoot growth of sawtimber tree on 

forest land 

FGROWCFAL TREE 96 Net annual sound cubic-foot 

growth of a live tree on forest 

land 

FGROWCFGS TREE 94 Net annual merchantable cubicfoot growth of growing-stock tree 

on forest land 

FIRE_SRS COND 87 Fire, Southern Research Station 

FLDAGE COND 52 Field-recorded stand age 

FLDSZCD (2.5.4) COND 21 Field stand-size class code 

FLDTYPCD (2.5.3) COND 17 Field forest type code 

FMORTBFSL TREE 98 Board-foot volume of a 

sawtimber tree for mortality 

purposes on forest land 

FMORTCFAL TREE 99 Sound cubic-foot volume of a tree 

for mortality purposes on forest 

land 

FMORTCFGS TREE 97 Cubic-foot volume of a growingstock tree for mortality purposes 

on forest land. 

FOOTNOTE REF_POP_ATTRIBUTE 12 Footnote 

FOREST_TYPE_SPGRPCD REF_SPECIES 12 Forest type species group code 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix A 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 249

Column name with (field guide 

section) Table name 

Location 

in table Description 

FORINDCD (2.5.8) COND 14 Private owner industrial status 

code 

FORMCL TREE 77 Form class 

FORTYPCD COND 16 Forest type code 

FORTYPCDCALC COND 55 Forest type code calculated with a 

national algorithm 

FREMVBFSL TREE 101 Board-foot volume of a 

sawtimber tree for removal 

purposes on forest land 

FREMVCFAL TREE 102 Sound cubic-foot volume of the 

tree for removal purposes on 

forest land 

FREMVCFGS TREE 100 Cubic-foot volume of a growingstock tree for removal purposes 

on forest land 

GENUS REF_SPECIES 3 Genus 

GRAZING_SRS COND 88 Grazing, Southern Research 

Station 

GROUND_LAND_CLASS_PNW COND 82 Present ground class code, Pacific 

Northwest Research Station 

GROW_TYP_CD PLOT 23 Type of annual volume growth 

code 

GROWBFSL TREE 46 Net annual merchantable boardfoot growth of sawtimber size tree 

on timberland 

GROWCFAL TREE 47 Net annual sound cubic-foot 

growth of a live tree on 

timberland 

GROWCFGS TREE 45 Net annual merchantable cubicfoot growth of growing-stock tree 

on timberland 

GSSTK COND 54 Growing-stock stocking percent 

GSSTKCD COND 36 Growing-stock stocking code 

HAPTYPCD REF_HABTYP_DESCRIPTION 2 Habitat type code 

HABTYPCD1 COND 56 Primary condition habitat type 

HABTYPCD1_DESCR_PUB_CD COND 58 Habitat type code 1 description 

publication code 

HABTYPCD1_PUB_CD COND 57 Habitat type code 1 publication 

code 

HABTYPCD2 COND 59 Secondary condition habitat type 

HABTYPCD2_DESCR_PUB_CD COND 61 Habitat type code 2 description 

publication code 

HABTYPCD2_PUB_CD COND 60 Habitat type code 2 publication 

code 

HARVEST_TYPE1_SRS COND 89 Harvest type code 1, Southern 

Research Station 

HARVEST_TYPE2_SRS COND 90 Harvest type code 2, Southern 

Research Station 

HARVEST_TYPE3_SRS COND 91 Harvest type code 3, Southern 

Research Station 

HIGHEST_POINT REF_STATE_ELEV 5 Highest point 

HRDWD_CLUMP_CD TREE 79 Hardwood clump code 

HT (7.24) SITETREE 13 Total height 

HT (5.14) TREE 20 Total height 

HTCALC TREE 78 Current height calculated 

HTCD (5.16) TREE 21 Height method code 

HTDMP (5.24) TREE 88 Length (height) to diameter 

measurement point 

INSTALL_TYPE REF_FIADB_VERSION 12 Install type 

INTENSITY PLOT 45 Intensity 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix A 

250 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Column name with (field guide 

section) Table name 

Location 

in table Description 

INVASIVE_NONSAMPLE_REASON

_CD 

SUBPLOT 34 Invasive nonsampled reason code 

INVASIVE_SAMPLING_STATUS_ 

CD 

PLOT 55 Invasive sampling status code 

INVASIVE_SPECIMEN_RULE_CD PLOT 56 Invasive specimen rule code 

INVASIVE_SUBP_STATUS_CD SUBPLOT 33 Invasive subplot status code 

INVYR BOUNDARY 3 Inventory year 

INVYR COND 3 Inventory year 

INVYR PLOT 5 Inventory year 

INVYR POP_PLOT_STRATUM_ ASSGN 5 Inventory year 

INVYR SEEDLING 3 Inventory year 

INVYR SITETREE 4 Inventory year 

INVYR SUBPLOT 4 Inventory year 

INVYR SUBP_COND 3 Inventory year 

INVYR SURVEY 2 Inventory year 

INVYR TREE 4 Inventory year 

JENKINS_FOLIAGE_RATIO_B1 REF_SPECIES 44 Jenkins foliage ratio B1 

JENKINS_FOLIAGE_RATIO_B2 REF_SPECIES 45 Jenkins foliage ratio B2 

JENKINS_ROOT_RATIO_B1 REF_SPECIES 46 Jenkins root ratio B1 

JENKINS_ROOT_RATIO_B2 REF_SPECIES 47 Jenkins root ratio B2 

JENKINS_SAPLING_ADJUSTMENT REF_SPECIES 49 Jenkins sapling adjustment factor 

JENKINS_SPGRPCD REF_SPECIES 37 Jenkins species group code 

JENKINS_STEM_BARK_RATIO_B1 REF_SPECIES 42 Jenkins stem bark ratio B1 

JENKINS_STEM_BARK_RATIO_B2 REF_SPECIES 43 Jenkins stem bark ratio B2 

JENKINS_STEM_WOOD_RATIO_B1 REF_SPECIES 40 Jenkins stem wood ratio B1 

JENKINS_STEM_WOOD_RATIO_B2 REF_SPECIES 41 Jenkins stem wood ratio B2 

JENKINS_TOTAL_B1 REF_SPECIES 38 Jenkins coefficient B1 

JENKINS_TOTAL_B2 REF_SPECIES 39 Jenkins coefficient B2 

KINDCD (1.7) PLOT 16 Sample kind code 

KINDCD_NC PLOT 31 Sample kind code, North Central 

LAND_ONLY POP_EVAL_GRP 12 Land only 

LAND_USE_SRS COND 92 Land use, Southern Research 

Station 

LAT (1.6.7) PLOT 20 Latitude 

LIVE_CANOPY_CVR_PCT COND 98 Live canopy cover percent 

LIVE_MISSING_CANOPY_CVR_ 

PCT 

COND 99 Live plus missing canopy cover 

percent 

LOCATION_NM POP_EVAL 6 Usually State name or super State 

LON (1.16.8) PLOT 21 Longitude 

LOWEST_POINT REF_STATE_ELEV 4 Lowest point 

MACRCOND SUBPLOT 14 Macroplot center condition 

MACRCOND_PROP SUBP_COND 18 Proportion of this macroplot in 

this condition 

MACRO_BREAKPOINT_DIA (1.17) PLOT 44 Macroplot breakpoint diameter 

MACRPROP_UNADJ COND 32 Macroplot proportion unadjusted 

MAJOR_SPGRPCD REF_SPECIES 10 Major species group code 

MANUAL (1.9) PLOT 29 Manual (field guide) version 

number 

MANUAL_END REF_FOREST_TYPE 5 Manual end 

MANUAL_END REF_SPECIES 29 Manual end 

MANUAL_START REF_FOREST_TYPE 4 Manual start 

MANUAL_START REF_SPECIES 28 Manual start 

MAPDEN COND 18 Mapping density 

MAX_ELEV REF_STATE_ELEV 3 Maximum elevation 

MC_PCT_GREEN BARK REF_SPECIES 55 Moisture content of green bark as 

a percent of oven-dry weight 

MC_PCT_GREEN_BARK_CIT REF_SPECIES 56 Moisture content of green bark 

citation 

MC_PCT_GREEN_WOOD REF_SPECIES 53 Moisture content of green wood 

as a percent of oven-dry weight 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix A 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 251

Column name with (field guide 

section) Table name 

Location 

in table Description 

MC_PCT_GREEN_WOOD_CIT REF_SPECIES 54 Moisture content of green wood 

citation 

MEANING REF_FOREST_TYPE 2 Meaning 

MEANING REF_UNIT 3 Meaning 

MEASDAY (1.10.3) PLOT 14 Measurement day 

MEASMON (1.10.2) PLOT 13 Measurement month 

MEASYEAR (1.10.1) PLOT 12 Measurement year 

METHOD SITETREE 21 Site tree method code 

MICRCOND (3.5) SUBPLOT 12 Microplot center condition 

MICRCOND_PROP SUBP_COND 16 Proportion of this microplot in 

this condition 

MICROPLOT_LOC PLOT 39 Microplot location 

MICRPROP_UNADJ COND 30 Microplot proportion unadjusted 

MIN_ELEV REF_STATE_ELEV 2 Minimum elevation 

MIST_CL_CD (5.26) TREE 90 Mistletoe class code 

MIST_CL_CD_PNWRS TREE 132 Leafy mistletoe class code, 

Pacific Northwest Research 

Station 

MIXEDCONFCD COND 62 Calculated forest type for mixed 

conifer site 

MODIFIED_BY BOUNDARY 21 Modified by 

MODIFIED_BY COND 76 Modified by 

MODIFIED_BY COUNTY 9 Modified by 

MODIFIED_BY PLOT 36 Modified by 

MODIFIED_BY POP_ESTN_UNIT 17 Modified by 

MODIFIED_BY POP_EVAL 12 Modified by 

MODIFIED_BY POP_EVAL_ATTRIBUTE 8 Modified by 

MODIFIED_BY POP_EVAL_GRP 16 Modified by 

MODIFIED_BY POP_EVAL_TYP 8 Modified by 

MODIFIED_BY POP_PLOT_STRATUM_ASSGN 16 Modified by 

MODIFIED_BY POP_STRATUM 18 Modified by 

MODIFIED_BY REF_CITATION 6 Modified by 

MODIFIED_BY REF_FIADB_VERSION 6 Modified by 

MODIFIED_BY REF_FOREST_TYPE 10 Modified by 

MODIFIED_BY REF_HABTYP_DESCRIPTION 10 Modified by 

MODIFIED_BY REF_HABTYP_PUBLICATION 10 Modified by 

MODIFIED_BY REF_POP_ATTRIBUTE 9 Modified by 

MODIFIED_BY REF_POP_EVAL_TYP_DESCR 6 Modified by 

MODIFIED_BY REF_SPECIES 33 Modified by 

MODIFIED_BY REF_SPECIES_GROUP 8 Modified by 

MODIFIED_BY REF_STATE_ELEV 9 Modified by 

MODIFIED_BY REF_UNIT 7 Modified by 

MODIFIED_BY SEEDLING 18 Modified by 

MODIFIED_BY SITETREE 28 Modified by 

MODIFIED_BY SUBPLOT 23 Modified by 

MODIFIED_BY SUBP_COND 13 Modified by 

MODIFIED_BY SUBP_COND_CHNG_MTRX 13 Modified by 

MODIFIED_BY SURVEY 13 Modified by 

MODIFIED_BY TREE 84 Modified by 

MODIFIED_BY TREE_REGIONAL_BIOMASS 8 Modified by 

MODIFIED_DATE BOUNDARY 22 Modified date 

MODIFIED_DATE COND 77 Modified date 

MODIFIED_DATE COUNTY 10 Modified date 

MODIFIED_DATE PLOT 37 Modified date 

MODIFIED_DATE POP_ESTN_UNIT 18 Modified date 

MODIFIED_DATE POP_EVAL 13 Modified date 

MODIFIED_DATE POP_EVAL_ATTRIBUTE 9 Modified date 

MODIFIED_DATE POP_EVAL_GRP 17 Modified date 

MODIFIED_DATE POP_EVAL_TYP 9 Modified date 

MODIFIED_DATE POP_PLOT_STRATUM_ASSGN 17 Modified date 

MODIFIED_DATE POP_STRATUM 19 Modified date 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix A 

252 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Column name with (field guide 

section) Table name 

Location 

in table Description 

MODIFIED_DATE REF_CITATION 7 Modified date 

MODIFIED_DATE REF_FIADB_VERSION 7 Modified date 

MODIFIED_DATE REF_FOREST_TYPE 11 Modified date 

MODIFIED_DATE REF_HABTYP_DESCRIPTION 11 Modified date 

MODIFIED_DATE REF_HABTYP_PUBLICATION 11 Modified date 

MODIFIED_DATE REF_POP_ATTRIBUTE 10 Modified date 

MODIFIED_DATE REF_POP_EVAL_TYP_DESCR 7 Modified date 

MODIFIED_DATE REF_SPECIES 34 Modified date 

MODIFIED_DATE REF_SPECIES_GROUP 9 Modified date 

MODIFIED_DATE REF_STATE_ELEV 10 Modified date 

MODIFIED_DATE REF_UNIT 8 Modified date 

MODIFIED_DATE SEEDLING 19 Modified date 

MODIFIED_DATE SITETREE 29 Modified date 

MODIFIED_DATE SUBPLOT 24 Modified date 

MODIFIED_DATE SUBP_COND 14 Modified date 

MODIFIED_DATE SUBP_COND_CHNG_MTRX 14 Modified date 

MODIFIED_DATE SURVEY 14 Modified date 

MODIFIED_DATE TREE 85 Modified date 

MODIFIED_DATE TREE_REGIONAL_BIOMASS 9 Modified date 

MODIFIED_IN_INSTANCE BOUNDARY 78 Modified in instance 

MODIFIED_IN_INSTANCE COND 78 Modified in instance 

MODIFIED_IN_INSTANCE COUNTY 11 Modified in instance 

MODIFIED_IN_INSTANCE PLOT 38 Modified in instance 

MODIFIED_IN_INSTANCE POP_ESTN_UNIT 19 Modified in instance 

MODIFIED_IN_INSTANCE POP_EVAL 14 Modified in instance 

MODIFIED_IN_INSTANCE POP_EVAL_ATTRIBUTE 10 Modified in instance 

MODIFIED_IN_INSTANCE POP_EVAL_GRP 18 Modified in instance 

MODIFIED_IN_INSTANCE POP_EVAL_TYP 10 Modified in instance 

MODIFIED_IN_INSTANCE POP_PLOT_STRATUM_ASSGN 18 Modified in instance 

MODIFIED_IN_INSTANCE POP_STRATUM 20 Modified in instance 

MODIFIED_IN_INSTANCE REF_CITATION 8 Modified in instance 

MODIFIED_IN_INSTANCE REF_FIADB_VERSION 8 Modified in instance 

MODIFIED_IN_INSTANCE REF_FOREST_TYPE 12 Modified in instance 

MODIFIED_IN_INSTANCE REF_HABTYP_DESCRIPTION 12 Modified in instance 

MODIFIED_IN_INSTANCE REF_HABTYP_PUBLICATION 12 Modified in instance 

MODIFIED_IN_INSTANCE REF_POP_ATTRIBUTE 11 Modified in instance 

MODIFIED_IN_INSTANCE REF_POP_EVAL_TYP_DESCR 8 Modified in instance 

MODIFIED_IN_INSTANCE REF_SPECIES 35 Modified in instance 

MODIFIED_IN_INSTANCE REF_SPECIES_GROUP 10 Modified in instance 

MODIFIED_IN_INSTANCE REF_STATE_ELEV 11 Modified in instance 

MODIFIED_IN_INSTANCE REF_UNIT 9 Modified in instance 

MODIFIED_IN_INSTANCE SEEDLING 20 Modified in instance 

MODIFIED_IN_INSTANCE SITETREE 30 Modified in instance 

MODIFIED_IN_INSTANCE SUBPLOT 25 Modified in instance 

MODIFIED_IN_INSTANCE SUBP_COND 15 Modified in instance 

MODIFIED_IN_INSTANCE SUBP_COND_CHNG_MTRX 15 Modified in instance 

MODIFIED_IN_INSTANCE SURVEY 15 Modified in instance 

MODIFIED_IN_INSTANCE TREE 86 Modified in instance 

MODIFIED_IN_INSTANCE TREE_REGIONAL_BIOMASS 10 Modified in instance 

MORT_TYP_CD PLOT 24 Type of annual mortality volume 

code 

MORTBFSL TREE 49 Board-foot volume of a 

sawtimber size tree on timberland 

for mortality purposes 

MORTCD (5.7.3) TREE 87 Mortality code 

MORTCFAL TREE 50 Sound cubic-foot volume of a tree 

on timberland for mortality 

purposes 

MORTCFGS TREE 48 Cubic-foot volume of a growingstock tree on timberland for 

mortality purposes 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix A 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 253

Column name with (field guide 

section) Table name 

Location 

in table Description 

MORTYR (5.22) TREE 55 Mortality year 

NAME REF_SPECIES_GROUP 2 Name 

NBR_LIVE_STEMS COND 100 Number of live stems 

NF_COND_NONSAMPLE_REASN_ 

CD 

COND 96 Nonforest condition nonsampled 

reason code 

NF_COND_STATUS_CD COND 95 Nonforest condition status code 

NF_PLOT_NONSAMPLE_REASN_ 

CD 

PLOT 52 Nonforest plot nonsampled reason 

code 

NF_PLOT_STATUS_CD PLOT 51 Nonforest plot status code 

NF_SAMPLING_STATUS_CD PLOT 50 Nonforest sampling status code 

NF_SUBP_NONSAMPLE_REASN_ 

CD 

SUBPLOT 30 Nonforest subplot nonsampled 

reason code 

NF_SUBP_STATUS_CD SUBPLOT 29 Nonforest subplot status code 

NONFR_INCL_PCT_MACRO SUBP_COND 20 Nonforest inclusions percentage 

of macroplot 

NONFR_INCL_PCT_SUBP SUBP_COND 19 Nonforest inclusions percentage 

of subplot 

NOTES POP_EVAL 8 Evaluation notes 

NOTES POP_EVAL_GRP 19 Notes 

NOTES SURVEY 9 Notes (about the inventory) 

OPERABILITY_SRS COND 93 Operability in Southern Research 

Station 

OWNCD (2.5.7) COND 12 Owner class code 

OWNGRPCD (2.5.2) COND 13 Owner group code 

P1PNTCNT_EU POP_ESTN_UNIT 12 Phase 1 point count (total number 

of pixels) in the estimation unit 

P1POINTCNT POP_STRATUM 9 Phase 1 point count 

P1SOURCE POP_ESTN_UNIT 13 Phase 1 source 

P2A_GRM_FLG SUBPLOT 19 Periodic to annual growth, 

removal, and mortality flag 

P2A_GRM_FLG TREE 103 Periodic to annual growth, 

removal, and mortality flag 

P2PANEL PLOT 25 Phase 2 panel number 

P2POINTCNT POP_STRATUM 10 Phase 2 point count 

P2VEG_SAMPLING_LEVEL_ 

DETAIL_CD 

PLOT 54 P2 vegetation sampling level 

detail code 

P2VEG_SAMPLING_STATUS_CD PLOT 53 P2 vegetation sampling status 

code 

P2VEG_SUBP_NONSAMPLE_ 

REASN_CD 

SUBPLOT 32 P2 vegetation nonsampled reason 

code 

P2VEG_SUBP_STATUS_CD SUBPLOT 31 P2 vegetation subplot status code 

P3_OZONE_IND SURVEY 3 Phase 3 ozone indicator plot. 

P3PANEL PLOT 26 Phase 3 panel number 

PHYSCLCD (2.5.23) COND 35 Physiographic class code 

PLANT_STOCKABILITY_FACTOR_ 

PNW 

COND 83 Plant stockability factor, Pacific 

Northwest Research Station 

PLOT BOUNDARY 7 Phase 2 Plot number 

PLOT COND 7 Phase 2 Plot number 

PLOT (1.3) PLOT 9 Phase 2 Plot number 

PLOT POP_PLOT_STRATUM_ASSGN 8 Phase 2 Plot number 

PLOT SEEDLING 7 Phase 2 Plot number 

PLOT SITETREE 8 Phase 2 Plot number 

PLOT SUBPLOT 8 Phase 2 Plot number 

PLOT SUBP_COND 7 Phase 2 Plot number 

PLOT TREE 8 Phase 2 Plot number 

PLOT_NONSAMPLE_REASN_CD 

(1.5) 

PLOT 11 Plot nonsampled reason code 

PLOT_STATUS_CD (1.4) PLOT 10 Plot status code 

PLT_CN BOUNDARY 2 Plot sequence number 

PLT_CN COND 2 Plot sequence number 

PLT_CN POP_PLOT_STRATUM_ASSGN 3 Plot sequence number 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix A 

254 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Column name with (field guide 

section) Table name 

Location 

in table Description 

PLT_CN SEEDLING 2 Plot sequence number 

PLT_CN SITETREE 2 Plot sequence number 

PLT_CN SUBPLOT 2 Plot sequence number 

PLT_CN SUBP_COND 2 Plot sequence number 

PLT_CN SUBP_COND_CHNG_MTRX 5 Plot sequence number 

PLT_CN TREE 2 Plot sequence number 

POINT_NONSAMPLE_REASN_CD 

(3.3) 

SUBPLOT 11 Point nonsampled reason code 

PRESNFCD COND 50 Present nonforest code 

PREV_PLT_CN PLOT 4 Previous plot sequence number 

PREV_PLT_CN SUBP_COND_CHNG_MTRX 7 Previous plot sequence number 

PREV_PNTN_SRS TREE 142 Previous periodic prism point, 

tree number, Southern Research 

Station 

PREV_SBP_CN SUBPLOT 3 Previous subplot sequence 

number 

PREV_SIT_CN SITETREE 3 Previous site tree sequence 

number 

PREV_STATUS_CD (5.6) TREE 109 Previous tree status code 

PREV_TRE_CN TREE 3 Previous tree sequence number 

PREV_WDLDSTEM (5.10) TREE 110 Previous woodland tree species 

stem count 

PREVCOND SUBP_COND_CHNG_MTRX 8 Previous condition class number 

PREVCOND TREE 14 Previous condition class number 

PREVDIA (5.9.1) TREE 93 Previous diameter 

PROP_BASIS COND 28 Proportion basis 

PUB_CD REF_HABTYP_DESCRIPTION 3 Publication code 

PUB_CD REF_HABTYP_PUBLICATION 2 Publication code 

QA_STATUS (1.14) PLOT 32 Quality assurance status 

RAILE_STUMP_DIB_B1 REF_SPECIES 62 Raile stump diameter inside bark 

equation coefficient B1 

RAILE_STUMP_DIB_B2 REF_SPECIES 63 Raile stump diameter inside bark 

equation coefficient B2 

RAILE_STUMP_DOB_B1 REF_SPECIES 61 Raile stump diameter outside bark 

equation coefficient B1 

RDDISTCD (1.12) PLOT 18 Horizontal distance to improved 

road code 

RECONCILECD (5.7.1) TREE 92 Reconcile code 

REGION REF_SPECIES_GROUP 3 Region 

REGIONAL_DRYBIOM TREE_REGIONAL_BIOMASS 4 Regional merchantable stem 

biomass oven-dry weight 

REGIONAL_DRYBIOT TREE_REGIONAL_BIOMASS 3 Regional total live tree biomass 

oven-dry weight 

REMPER PLOT 15 Remeasurement period 

REMVBFSL TREE 52 Board-foot volume of a 

sawtimber size tree on timberland 

for removal purposes 

REMVCFAL TREE 53 Sound cubic-foot volume of a tree 

on timberland for removal 

purposes 

REMVCFGS TREE 51 Cubic-foot volume of a growingstock tree on timberland for 

removal purposes 

REPORT_YEAR_NM POP_EVAL 7 Report year name 

RESERVCD (2.5.1) COND 11 Reserved status code 

ROOT_DIS_SEV_CD_PNWRS SUBPLOT 28 Root disease severity rating code, 

Pacific Northwest Research 

Station 

ROUGHCULL (5.25) TREE 89 Rough cull percentage 

RSCD POP_ESTN_UNIT 3 Region or Station code 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix A 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 255

Column name with (field guide 

section) Table name 

Location 

in table Description 

RSCD POP_EVAL 2 Region or Station code 

RSCD POP_EVAL_GRP 8 Region or Station code 

RSCD POP_PLOT_STRATUM_ ASSGN 9 Region or Station code 

RSCD POP_STRATUM 3 Region or Station code 

RSCD SURVEY 7 Region or Station code 

SALVCD TREE 56 Salvable dead code 

SAMP_METHOD_CD PLOT 42 Sample method code 

SAWHT TREE 75 Sawlog height 

SCIENTIFIC_NAME REF_HABTYP_DESCRIPTION 4 Scientific name 

SEVERITY1_CD_PNWRS TREE 133 Damage severity 1, Pacific 

Northwest Research Station, for 

years 2001-2004 

SEVERITY1A_CD_PNWRS TREE 134 Damage Severity 1, Pacific 

Northwest Research Station 

SEVERITY1B_CD_PNWRS TREE 135 Damage severity B, Pacific 

Northwest Research Station 

SEVERITY2_CD_PNWRS TREE 136 Damage severity 2, Pacific 

Northwest Research Station, for 

years 2001-2004 

SEVERITY2A_CD_PNWRS TREE 137 Damage severity 2A, Pacific 

Northwest Research Station, 

starting in 2005 

SEVERITY2B_CD_PNWRS TREE 138 Damage severity in 2B, Pacific 

Northwest Research Station, 

starting in 2005 

SEVERITY3_CD_PNWRS TREE 139 Damage severity 3, Pacific 

Northwest Research Station, for 

years 2001-2004 

SFTWD_HRDWD REF_SPECIES 19 Softwood or hardwood 

SIBASE COND 24 Site index base age 

SIBASE SITETREE 17 Site index base age 

SICOND COND 23 Site index for the condition 

SISP COND 25 Site index species code 

SITECL_METHOD COND 66 Site class method 

SITECLCD COND 22 Site productivity class code 

SITECLCDEST COND 64 Site productivity class code 

estimated 

SITETREE REF_SPECIES 18 Site tree 

SITETREE_TREE COND 65 Site tree tree number 

SITREE SITETREE 16 Site index for the tree 

SITREE TREE 80 Calculated site index 

SITREE_EST SITETREE 22 Estimated site index for the tree 

SLOPE COND 33 Slope 

SLOPE (3.6) SUBPLOT 16 Subplot slope 

SOIL_ROOTING_DEPTH_PNW COND 81 Soil rooting depth code, Pacific 

Northwest Research Station 

SPCD REF_SPECIES 1 Species code 

SPCD (6.2) SEEDLING 10 Species code 

SPCD (7.2.2) SITETREE 11 Species code 

SPCD (5.8) TREE 16 Species code 

SPECIES REF_SPECIES 4 Species name 

SPECIES_SYMBOL REF_SPECIES 7 Species symbol 

SPGRPCD REF_SPECIES_GROUP 1 Species group code 

SPGRPCD SEEDLING 11 Species group code 

SPGRPCD SITETREE 15 Species group code 

SPGRPCD TREE 17 Species group code 

SRV_CN PLOT 2 Survey sequence number 

ST_EXISTS_IN_NCRS REF_SPECIES 20 Site tree exists in the North 

Central Research Station region 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix A 

256 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Column name with (field guide 

section) Table name 

Location 

in table Description 

ST_EXISTS_IN_NERS REF_SPECIES 21 Site tree exists in the Northeastern 

Research Station region 

ST_EXISTS_IN_PNWRS REF_SPECIES 22 Site tree exists in the Pacific 

Northwest Research Station 

region 

ST_EXISTS_IN_RMRS REF_SPECIES 23 Site tree exists in the Rocky 

Mountain Research Station region 

ST_EXISTS_IN_SRS REF_SPECIES 24 Site tree exists in the Southern 

Research Station region 

STAND_STRUCTURE_SRS COND 94 Stand structure, Southern 

Research Station 

STANDING_DEAD_CD (5.7.2) TREE 108 Standing dead code 

START_INVYR POP_EVAL 15 Start inventory year 

STATEAB SURVEY 5 State abbreviation 

STATECD BOUNDARY 4 State code 

STATECD COND 4 State code 

STATECD COUNTY 1 State code 

STATECD (1.1) PLOT 6 State code 

STATECD POP_ESTN_UNIT 7 State code 

STATECD POP_EVAL 5 State code 

STATECD POP_EVAL_ATTRIBUTE 4 State code 

STATECD POP_EVAL_GRP 11 State code 

STATECD POP_EVAL_TYP 4 State code 

STATECD POP_PLOT_STRATUM_ASSGN 4 State code 

STATECD POP_STRATUM 8 State code 

STATECD REF_STATE_ELEV 1 State code 

STATECD REF_UNIT 1 State code 

STATECD SEEDLING 4 State code 

STATECD SITETREE 5 State code 

STATECD SUBPLOT 5 State code 

STATECD SUBP_COND 4 State code 

STATECD SUBP_COND_CHNG_MTRX 2 State code 

STATECD SURVEY 4 State code 

STATECD TREE 5 State code 

STATECD TREE_REGIONAL_BIOMASS 2 State code 

STATENM SURVEY 6 State name 

STATUSCD TREE 15 Status code 

STDAGE (2.5.10) COND 19 Stand age 

STDORGCD COND 26 Stand origin code 

STDORGSP COND 27 Stand origin species code 

STDSZCD COND 20 Stand-size class code derived by 

algorithm 

STND_COND_CD_PNWRS COND 84 Stand condition code, Pacific 

Northwest Research Station 

STND_STRUC_CD_PNWRS COND 85 Stand structure code, Pacific 

Northwest Research Station 

STOCKING SEEDLING 12 Tree stocking 

STOCKING TREE 36 Tree stocking 

STOCKING_SPGRPCD REF_SPECIES 11 Stocking species group code 

STRATUM_CN POP_PLOT_STRATUM_ASSGN 2 Stratum sequence number 

STRATUM_DESCR POP_STRATUM 7 Stratum description 

STRATUMCD POP_PLOT_STRATUM_ASSGN 12 Stratum code 

STRATUMCD POP_STRATUM 6 Stratum code 

STUMP_CD_PNWRS COND 86 Stump code, Pacific Northwest 

Research Station 

SUBCYCLE BOUNDARY 17 Inventory subcycle number 

SUBCYCLE COND 80 Inventory subcycle number 

SUBCYCLE PLOT 47 Inventory subcycle number 

SUBCYCLE SEEDLING 24 Inventory subcycle number 

SUBCYCLE SITETREE 32 Inventory subcycle number 

SUBCYCLE SUBPLOT 27 Inventory subcycle number 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix A 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 257

Column name with (field guide 

section) Table name 

Location 

in table Description 

SUBCYCLE SUBP_COND 22 Inventory subcycle number 

SUBCYCLE SURVEY 17 Inventory subcycle number 

SUBCYCLE TREE 124 Inventory subcycle number 

SUBP (4.2.1) BOUNDARY 8 Subplot number 

SUBP (6.1) SEEDLING 8 Subplot number 

SUBP (7.2.7) SITETREE 18 Subplot number 

SUBP (3.1) SUBPLOT 9 Subplot number 

SUBP SUBP_COND 8 Subplot number 

SUBP SUBP_COND_CHNG_MTRX 3 Subplot number 

SUBP (5.1) TREE 9 Subplot number 

SUBP_EXAMINE_CD (1.6) PLOT 43 Subplots examined code 

SUBP_STATUS_CD (3.2) SUBPLOT 10 Subplot status code 

SUBPANEL PLOT 30 Subpanel 

SUBPCOND (3.4) SUBPLOT 13 Subplot center condition 

SUBPCOND_PROP SUBP_COND 17 Proportion of this subplot in this 

condition 

SUBPPROP_UNADJ COND 31 Subplot proportion unadjusted 

SUBPTYP (4.2.2) BOUNDARY 9 Subplot type code 

SUBPTYP SUBP_COND_CHNG_MTRX 4 Subplot type code 

SUBPTYP_PROP_CHNG SUBP_COND_CHNG_MTRX 9 Percent change of subplot 

condition between previous to 

current inventory 

SUBSPECIES REF_SPECIES 6 Subspecies name 

TITLE REF_HABTYP_PUBLICATION 3 Title of publication 

TOPO_POSITION_PNW PLOT 49 Topographic position, Pacific 

Northwest Research Station 

TOTAGE SEEDLING 14 Total age of seedling 

TOTAGE TREE 67 Total tree age 

TPA_UNADJ SEEDLING 22 Trees per acre unadjusted 

TPA_UNADJ TREE 111 Trees per acre unadjusted 

TPAGROW_UNADJ TREE 114 Growth trees per acre unadjusted 

for denied access, hazardous, out 

of sample conditions 

TPAMORT_UNADJ TREE 112 Mortality trees per acre per year 

unadjusted for denied access, 

hazardous, out of sample 

conditions 

TPAREMV_UNADJ TREE 113 Removal trees per acre per year 

unadjusted for denied access, 

hazardous, out of sample 

conditions 

TRANSCD (12.11) TREE 63 Foliage transparency code 

TRE_CN TREE_REGIONAL_BIOMASS 1 Tree sequence number 

TREE SITETREE 10 Tree number 

TREE (5.2) TREE 10 Tree record number 

TREECLCD TREE 23 Tree class code 

TREECLCD_NCRS TREE 106 Tree class code, North Central 

Research Station 

TREECLCD_NERS TREE 104 Tree class code, Northeastern 

Research Station 

TREECLCD_RMRS TREE 107 Tree class code, Rocky Mountain 

Research Station 

TREECLCD_SRS TREE 105 Tree class code, Southern 

Research Station 

TREECOUNT (6.4) SEEDLING 13 Tree count for seedlings 

TREECOUNT_CALC SEEDLING 21 Tree count used in calculations 

TREEGRCD TREE 26 Tree grade code 

TREEHISTCD TREE 64 Tree history code 

TRTCD1 (2.5.17) COND 44 Stand Treatment 1 code 

TRTCD2 (2.5.19) COND 46 Stand treatment 2 code 

TRTCD3 (2.5.21) COND 48 Stand Treatment 3 code 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix A 

258 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Column name with (field guide 

section) Table name 

Location 

in table Description 

TRTYR1 (2.5.18) COND 45 Treatment year 1 

TRTYR2 (2.5.20) COND 47 Treatment year 2 

TRTYR3 2.5.22) COND 49 Treatment year 3 

TYPE REF_HABTYP_PUBLICATION 5 Type of publication 

TYPGRPCD REF_FOREST_TYPE 3 Forest type group code 

UNCRCD (5.18, 12.5) TREE 57 Uncompacted live crown ratio 

UNITCD BOUNDARY 5 Survey unit code 

UNITCD COND 5 Survey unit code 

UNITCD COUNTY 2 Survey unit code 

UNITCD PLOT 7 Survey unit code 

UNITCD POP_PLOT_STRATUM_ ASSGN 6 Survey unit code 

UNITCD SEEDLING 5 Survey unit code 

UNITCD SITETREE 6 Survey unit code 

UNITCD SUBPLOT 6 Survey unit code 

UNITCD SUBP_COND 5 Survey unit code 

UNITCD TREE 6 Survey unit code 

UNKNOWN_DAMTYP1_PNWRS TREE 140 Unknown damage type 1, Pacific 

Northwest Research Station 

UNKNOWN_DAMTYP2_PNWRS TREE 141 Unknown damage type 2, Pacific 

Northwest Research Station 

VALID REF_HABTYP_DESCRIPTION 6 Valid 

VALID REF_HABTYP_PUBLICATION 6 Valid 

VALIDCD SITETREE 23 Validity code 

VALUE REF_FOREST_TYPE 1 Value 

VALUE REF_UNIT 2 Value 

VARIETY REF_SPECIES 5 Variety 

VERSION REF_FIADB_VERSION 1 Version number 

VOL_LOC_GRP COND 63 Volume location group 

VOLBFGRS TREE 43 Gross board-foot volume in the 

sawlog portion 

VOLBFNET TREE 42 Net board-foot volume in the 

sawlog portion 

VOLCFGRS TREE 39 Gross cubic-foot volume 

VOLCFNET TREE 38 Net cubic-foot volume 

VOLCFSND TREE 44 Sound cubic-foot volume 

VOLCSGRS TREE 41 Gross cubic-foot volume in the 

sawlog portion 

VOLCSNET TREE 40 Net cubic-foot volume in the 

sawlog portion 

W_SPGRPCD REF_SPECIES 9 West species group code 

WATERCD (1.13) PLOT 19 Water on plot code 

WATERDEP (3.8) SUBPLOT 18 Water or snow depth 

WDLDSTEM (5.11) TREE 37 Woodland tree species current 

stem count 

WEST REF_SPECIES 26 West 

WHERE_CLAUSE REF_POP_ATTRIBUTE 5 Part of the where clause 

WOOD_SPGR_GREENVOL_ 

DRYWT 

REF_SPECIES 49 Green specific gravity wood 

(green volume and oven-dry 

weight) 

WOOD_SPGR_GREENVOL_ 

DRYWT_CIT 

REF_SPECIES 50 Green specific gravity wood 

citation 

WOOD_SPGR_MC12VOL_DRYWT REF_SPECIES 57 Wood specific gravity (12 percent 

moisture content volume and 

oven-dry weight) 

WOOD_SPGR_MC12VOL_DRYWT_ 

CIT 

REF_SPECIES 58 Wood specific gravity (12 percent 

moisture content volume and 

oven-dry weight) citation 

WOODLAND REF_SPECIES 27 Woodland species 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix B 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 259

Appendix B. Forest Inventory and Analysis (FIA) Plot Design Codes and Definitions 

 by FIA Work Unit 

FIA work 

unit 

Plot design 

code 

(DESIGNCD) 

Definition 

a

NRS-NE, 

b

NRS-NC, 

c

SRS, 

d

RMRS, 

e

PNWRS 1 

National plot design consists of four 24-foot fixed-radius subplots for 

trees ≥5 inches DBH, and four 6.8-foot fixed-radius microplots for seedlings 

and trees ≥1 and <5 inches DBH. Subplot 1 is the center plot, and subplots 2, 3, 

and 4 are located 120.0 feet, horizontal, at azimuths of 360, 120, and 240, 

respectively. The microplot center is 12 feet east of the subplot center. Four 

58.9-foot fixed-radius macroplots are optional. A plot may sample more than 

one condition. When multiple conditions are encountered, condition boundaries 

are delineated (mapped). a

NRS-NE 101 Various plot designs. Converted from Eastwide Database format, some fields 

may be null. 

111 

Four-subplot design similar to DESIGNCD 1, except the microplot for seedlings 

is 1/1000 acre (3.7-foot radius). If the plot is used for growth estimates, it is 

overlaid on a 5 subplot design, where remeasurement of trees (≥5 inches) is on 

subplot 1 only. Poletimber-sized trees remeasured on a 24-foot radius plot, 

sawtimber-sized trees remeasured on a 49-foot radius plot. If the plot is not used 

for growth estimates, it is an initial plot establishment. 

112 

DESIGNCD 111, except that if the plot is used for growth estimates, the 

remeasurement of trees (≥5 inches) is on the 24-foot-radius subplot 1 only, 

regardless of tree size or previous plot size or type (varied). 

113 

DESIGNCD 111, except that if the plot is used for growth estimates, the 

remeasurement of trees (≥5 inches) is on the 24-foot-radius subplot 1 only, 

regardless of tree size or previous plot size or type (single subplot 1/5 acre). 

115 DESIGNCD 1. Overlaid on a FHM 4-subplot plot design. These plots are not 

used in change estimates. 

116 

DESIGNCD 1. Overlaid on 1/5 acre plot for all trees ≥5 inches DBH (1/5 acre 

plot was an initial measurement). Remeasurement of subplot 1 is only on the 

24-foot-radius plot for all trees (≥5 inches), regardless of tree size or previous 

plot size. 

117 DESIGNCD 1. Overlaid on 1/5 acre plot for all trees ≥5 inches DBH (1/5 acre 

plot was remeasurement). Remeasurement of subplot 1 is only on the 24-footradius plot for all trees (≥5 inches), regardless of tree size or previous plot size. 

118 DESIGNCD 1. Overlaid on 10-subplot, variable-radius design. Remeasurement 

of trees (≥5 inches) on 5 of the 10 subplots; ingrowth based on trees (≥5 inches) 

that grew onto five 6.8-foot radius subplots. 

b

NRS-NC 301 Various plot designs. Converted from Eastwide Database format, some fields 

may be null. 

311 

Four-subplot design similar to DESIGNCD 1, except the 1/24 acre and 1/300 

acre plots have common centers. Conditions are mapped and boundaries may be 

within the plots. 

312 DESIGNCD 1. Initial plot establishment. 

313 DESIGNCD 311. Overlaid on previous plots, no remeasurements. 

314 DESIGNCD 1. Overlaid on previous plots, no remeasurements. 

315 DESIGNCD 311. Overlaid on same design. Only trees ≥5 inches DBH are 

remeasured. 

316 DESIGNCD 1. Overlaid on DESIGNCD 311 Only trees ≥5 inches DBH are 

remeasured. 

317 

DESIGNCD 1. Overlaid on DESIGNCD 326. Only the first 5 points 

(trees ≥5 inches DBH) and first 3, 1/300 acre plots (trees ≥1 and <5 inches 

DBH) are remeasured, but conditions were not re-mapped. 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix B 

260 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

FIA work 

unit 

Plot design 

code 

(DESIGNCD) 

Definition 

318 

DESIGNCD 311. Overlaid on DESIGNCD 325. Only the first 5 points 

(trees ≥5 inches DBH) and first 3, 1/300 acre plots (trees ≥1 and <5 inches 

DBH) are remeasured. 

319 

DESIGNCD 1. Overlaid on DESIGNCD 325. Only the first 5 points 

(trees ≥5 inches DBH) and first 3, 1/300 acre plots (trees ≥1 and <5 inches 

DBH) are remeasured. 

320 

DESIGNCD 311. Overlaid on modified DESIGNCD 325. Only the first 5 

points (trees ≥5 inches DBH) and first 3 1/300 acre plots (trees ≥1 and 

<5 inches DBH) are remeasured. 

321 

DESIGNCD 1. Overlaid on modified DESIGNCD 325. Only the first 5 points 

(trees ≥5 inches DBH) and first 3 1/300 acre plots (trees ≥1 and <5 inches 

DBH) are remeasured. 

322 

DESIGNCD 311. Overlaid on DESIGNCD 327. Only the first 5 points 

(trees ≥5 inches DBH) and first 3, 1/300 acre plots (trees ≥1 and <5 inches 

DBH) are remeasured. 

323 

DESIGNCD 1. Overlaid on DESIGNCD 327. Only the first 5 points 

(trees ≥5 inches DBH) and first 3 1/300 acre plots (trees ≥1 and <5 inches 

DBH) are remeasured. 

325 

Ten variable-radius, 37.5 BAF points, 70 feet apart, for trees ≥5 inches DBH 

and 10, 1/300 acre plots for seedlings and trees ≥1 and <5 inches DBH. Point 

and plot center were coincident. Conditions were not mapped. Instead, points 

were rotated into forest or nonforest based on the condition at point center. 

326 

Ten variable-radius, 37.5 BAF points, 70 feet apart, for trees ≥5 and 

<17.0 inches DBH, 10 1/24 acre plots for trees ≥17.0 inches DBH, and 10, 

1/300 acre plots for seedlings and trees ≥1 and <5 inches DBH. Point and plot 

center were coincident. Conditions were mapped. 

327 

Ten variable-radius, 37.5 BAF points, 70 feet apart, for trees ≥5 inches DBH 

and 10, 1/300 acre plots for seedlings and trees ≥1 and <5 inches DBH. Point 

and plot center were coincident. Conditions were not mapped. Instead, points 

were rotated into forest or nonforest based on the condition at point center. 

Diameters were estimated with a model, but all dead and cut trees were 

recorded. 

328 DESIGNCD 1. Overlaid on DESIGNCD 311. All trees and saplings are 

remeasured. c

SRS 210 Other plot design installed by previous research stations within the 13-State 

Southern area not described by DESIGNCD 211-219. 

211 Ten variable-radius, 37.5 BAF points, 70 feet apart. Remeasure first 3 points of 

same design or new/replacement plot. 

212 Five variable-radius, 37.5 BAF points, 70 feet apart. Remeasure first 5 points of 

DESIGNCD 211 or new/replacement plot. 

213 Five variable-radius, 37.5 BAF points, 70 feet apart. Remeasure DESIGNCD 

212. 

214 Ten variable-radius, 37.5 BAF points, 66 feet apart. Remeasure same design or 

new/replacement plot. 

215 Five variable-radius, 37.5 BAF points, 66 feet apart. Remeasure first 5 points of 

DESIGNCD 214 or new/replacement plot. 

216 Ten variable-radius, 37.5 BAF points, 66 feet apart. Remeasure DESIGNCD 

215. 

217 Five point cluster plot, point 1 is 1/5th acre sawtimber plot and 1/10th acre 

poletimber plot, points 2-5 are 37.5 BAF prism points. No remeasurement. 

218 Remeasurement of DESIGNCD 217, point 1 only. Used only for change 

estimates. 

219 Three point, 2.5 BAF metric prism plot, points 25 meters apart. Remeasure 

same design or new/replacement plot. 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix B 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 261

FIA work 

unit 

Plot design 

code 

(DESIGNCD) 

Definition 

220 

Four 1/24 acre plots for trees ≥5 inches DBH and 4, 1/300 acre plots for 

seedlings and trees ≥1 and <5 inches DBH. The 1/24 acre and 1/300 acre plots 

have common centers. Conditions are mapped and boundaries may be within the 

plots. Remeasurement plot not described by 221-229. 

221 DESIGNCD 220. Remeasure same design or new/replacement plot. 

222 DESIGNCD 220. Overlaid on and remeasurement of DESIGNCD 212 or 213. 

223 DESIGNCD 220. Overlaid on and remeasurement of first 5 points of 

DESIGNCD 214 or 216. 

230 DESIGNCD 1. Remeasurement plot not described by DESIGNCD 231-239. 

231 DESIGNCD 1. Overlaid on and remeasurement of DESIGNCD 212 or 

DESIGNCD 213. 

232 DESIGNCD 1. Overlaid on and remeasurement of first 5 points of DESIGNCD 

214 or 216. 

233 DESIGNCD 1. Overlaid on and remeasurement of DESIGNCD 220, 221, 222, 

or 223 

240 DESIGNCD 1. Collected in metric and converted to English in the database. 

Remeasurement not described by 241-249. 

241 DESIGNCD 1. Collected in metric and converted to English in the database. 

Remeasure same design or new/replacement plot. 

242 DESIGNCD 1. Overlaid on and remeasurement of DESIGNCD 219. Collected 

in metric and converted to English in the database. 

299 Other plot design not described in DESIGNCD 200-298. 

d

RMRS 

403 

One 1/10th acre fixed-radius plot divided into 4 quadrants and four 1/300th acre 

fixed-radius microplots. Timber and woodland tree species <5.0 inches DRC 

tallied on microplot. 

404 

One 1/20th acre fixed-radius plot divided into 4 quadrants and four 1/300th acre 

fixed-radius microplots. Timber and woodland tree species <5.0 inches DRC 

tallied on microplot. 

405 

One 1/5th acre fixed-radius plot divided into 4 quadrants and four 1/300th acre 

fixed-radius microplots. Timber and woodland tree species <5.0 inches DRC 

tallied on microplot. 

410 

40 BAF variable-radius plots and 1/300th acre fixed-radius microplots; number 

of microplots = number of points installed. Timber tree species <5.0 inches 

DBH; woodland tree species <3.0 inches DRC measured on microplot. 

411 

40 BAF variable-radius plots and 1/300th acre fixed-radius microplots; 3 

microplots installed on points 1, 2, and 3. Timber tree species <5.0 inches DBH; 

woodland tree species <3.0 inches DRC measured on microplot. 

412 

40 BAF variable-radius plots and 1/300th acre fixed-radius microplots; 3 

microplots installed on points 1, 2, and 5. Timber tree species <5.0 inches DBH; 

woodland tree species <3.0 inches DRC measured on microplot. 

413 

20 BAF variable-radius plots and 1/300th acre fixed-radius microplots; number 

of microplots = number of points installed. Timber tree species <5.0 inches 

DBH; woodland tree species <3.0 inches DRC measured on microplot. 

414 

20 BAF variable-radius plots and 1/300th acre fixed-radius microplots; 3 

microplots installed on points 1, 2, and 3. Timber tree species <5.0 inches DBH; 

woodland tree species <3.0 inches DRC measured on microplot. 

415 

20 BAF variable-radius plots and 1/300th acre fixed-radius microplots; 3 

microplots installed on points 1, 2, and 5. Timber tree species <5.0 inches DBH; 

woodland tree species <3.0 inches DRC measured on microplot. 

420 

One 1/10th acre fixed-radius plot and one centered 1/100th acre microplot. 

Timber tree species <5.0 inches DBH; woodland tree species <3.0 inches DRC 

measured on microplot. 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix B 

262 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

FIA work 

unit 

Plot design 

code 

(DESIGNCD) 

Definition 

421 

One 1/20th acre fixed-radius plot and one centered 1/100th acre microplot. 

Timber tree species <5.0 inches DBH; woodland tree species <3.0 inches DRC 

measured on microplot. 

422 

One 1/5th acre fixed-radius plot and one centered 1/100th acre microplot. 

Timber tree species <5.0 inches DBH; woodland tree species <3.0 inches DRC 

measured on microplot. 

423 

One 1/10th acre fixed-radius plot divided into 4 quadrants and four 1/300th acre 

fixed-radius microplots. Timber tree species <5.0 inches DBH; woodland tree 

species <3.0 inches DRC measured on microplot. 

424 

One 1/20th acre fixed-radius plot divided into 4 quadrants and four 1/300th acre 

fixed-radius microplots. Timber tree species <5.0 inches DBH; woodland tree 

species <3.0 inches DRC measured on microplot. 

425 

One 1/5th acre fixed-radius plot divided into 4 quadrants and four 1/300th acre 

fixed-radius microplots. Timber tree species <5.0 inches DBH; woodland tree 

species <3.0 inches DRC measured on microplot. e

PNWRS 501 DESIGNCD 1 with optional macroplot. Trees ≥24 inches DBH are tallied on 

macroplot. 

502 DESIGNCD 1 with optional macroplot. Trees ≥30 inches DBH are tallied on 

macroplot. 

503 DESIGNCD 1 with optional macroplot. Trees ≥4 inches DBH are tallied on 

macroplot. Trees ≥32 inches DBH are tallied on one 1-hectare plot. 

504 DESIGNCD 1 with optional macroplot. Trees ≥24 inches DBH are tallied on 

macroplot. Trees ≥48 inches DBH are tallied on one 1-hectare plot. 

505 DESIGNCD 1 with optional macroplot. Trees ≥30 inches DBH are tallied on 

macroplot. Trees ≥48 inches DBH are tallied on one 1-hectare plot. 

550 

Five 30.5 BAF points for trees ≥5 inches and <35.4 inches DBH; five 55.8 foot 

fixed-radius plots for trees ≥35.4 inches DBH; and five 7.7-foot fixed-radius 

plots for seedlings and saplings <5 inches DBH. Point and plot centers are 

coincident. Conditions are mapped. 

551 

Five 20 BAF points for trees ≥5 inches and <35.4 inches DBH; five 55.6 foot 

fixed-radius plots for trees ≥35.4 inches DBH; and five 9.7-foot fixed-radius 

plots for seedlings and saplings <5 inches DBH. Point and plot centers are 

coincident. Conditions are mapped. 

552 

Five 30 BAF points for trees ≥5 inches and <35.4 inches DBH; five 55.6-foot 

fixed-radius plots for trees ≥35.4 inches DBH; and five 7.9-foot fixed-radius 

plots for seedlings and saplings <5 inches DBH. Point and plot centers are 

coincident. Conditions are mapped. 

553 Four 1/24 acre plots for live trees and four 58.9-foot fixed-radius plots for trees 

≥11.8 inches DBH. Plot centers are coincident. Conditions are mapped. 

554 Four 1/24 acre plots for live trees and four 58.9-foot fixed-radius plots for trees 

≥19.7 inches DBH. Plot centers are coincident. Conditions are mapped. 

555 

Five 30.5 BAF points for trees ≥6.9 inches and <35.4 inches DBH; five 

55.8-foot fixed-radius plots for trees ≥35.4 inches DBH; and five 10.8-foot 

fixed-radius plots for seedlings and saplings <6.9 inches DBH. Point and plot 

centers are coincident. Conditions are mapped. 

556 

Five 30.5 BAF points for trees ≥6.9 inches and <35.4 inches DBH; five 

55.8-foot fixed-radius plots for trees ≥35.4 inches DBH; five 10.8-foot fixedradius plots for saplings ≥5 inches and <6.9 inches DBH; and the northeast 

quadrant of each of the five 10.8-foot fixed-radius plots for trees <5 inches 

DBH. Point and plot centers are coincident. Conditions are not mapped. 

557 

Five 40 BAF points for trees ≥5 inches DBH; and five 6.9-foot fixed-radius 

plots for saplings ≥1 and <5 inches DBH. Point and plot centers are coincident. 

Conditions are not mapped. 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix B 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 263

FIA work 

unit 

Plot design 

code 

(DESIGNCD) 

Definition 

558 

Three 30.5 BAF points for trees ≥6.9 inches and <35.4 inches DBH; three 

55.8-foot fixed-radius plots for trees ≥35.4 inches DBH; three 10.8-foot fixedradius plots for saplings ≥5 inches and <6.9 inches DBH; and the northeast 

quadrant of each of the three 10.8-foot fixed-radius plots for trees <5 inches 

DBH. Point and plot centers are coincident. Conditions are mapped, only 

condition class 1 measured. Overlaid on and remeasurement of same design. 

559 

Four 40 BAF points for trees ≥5 inches DBH; and four 6.9-foot fixed-radius 

plots for saplings ≥1 and <5 inches DBH. Point and plot centers are coincident. 

Conditions are mapped, only condition class 1 measured. Overlaid on and 

remeasurement of same design. a

NRS-NE, 

b

NRS-NC, 

c

SRS, 

d

RMRS, 

e

PNWRS 

999 

A plot record created to represent reserved or other nonsampled or 

undersampled areas where there were no ground plots; the plot has no design 

type; rather, it is a placeholder for area estimates. In all cases where 

DESIGNCD 999 plots are present, they are only used for estimates of area; they 

are not used in estimates of numbers of trees, volume or change (i.e., tree level 

estimates). 

a

Northern Research Station – previously Northeastern 

b

Northern Research Station – previously North Central 

c

Southern Research Station 

d

Rocky Mountain Research Station 

e

Pacific Northwest Research Station 

Other acronyms and definitions: 

BAF – basal area factor 

DRC – diameter at root collar 

Sawtimber-sized trees – softwoods ≥9 inches DBH, hardwoods ≥11 inches DBH. 

Poletimber-sized trees – softwoods ≥5 inches and <9 inches DBH, hardwoods ≥5 inches and <11 inches DBH 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

264 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Appendix C. State, Survey Unit, and County Codes 

State Code: 1 State Name: Alabama State Abbreviation: AL Region/Station Code: 33 

Survey Unit Code: 1 Survey Unit Name: Southwest-South 

County code and county name

3 Baldwin 53 Escambia 129 Washington 

39 Covington 97 Mobile 

 

Survey Unit Code: 2 Survey Unit Name: Southwest-North 

County code and county name

23 Choctaw 35 Conecuh 99 Monroe 131 Wilcox 

25 Clarke 91 Marengo 119 Sumter 

 

Survey Unit Code: 3 Survey Unit Name: Southeast 

County code and county name

1 Autauga 31 Coffee 67 Henry 109 Pike 

5 Barbour 41 Crenshaw 69 Houston 113 Russell 

11 Bullock 45 Dale 81 Lee 123 Tallapoosa 

13 Butler 47 Dallas 85 Lowndes 

17 Chambers 51 Elmore 87 Macon 

21 Chilton 61 Geneva 101 Montgomery 

 

Survey Unit Code: 4 Survey Unit Name: West Central 

County code and county name

7 Bibb 65 Hale 105 Perry 

57 Fayette 75 Lamar 107 Pickens 

63 Greene 93 Marion 125 Tuscaloosa 

 

Survey Unit Code: 5 Survey Unit Name: North Central 

County code and county name

9 Blount 29 Cleburne 73 Jefferson 121 Talladega 

15 Calhoun 37 Coosa 111 Randolph 127 Walker 

19 Cherokee 43 Cullman 115 St. Clair 133 Winston 

27 Clay 55 Etowah 117 Shelby 

 

Survey Unit Code: 6 Survey Unit Name: North 

County code and county name

33 Colbert 71 Jackson 83 Limestone 103 Morgan 

49 DeKalb 77 Lauderdale 89 Madison 

59 Franklin 79 Lawrence 95 Marshall 

 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 265

State Code: 2 State Name: Alaska State Abbreviation: AK Region/Station Code: 27 

Survey Unit Code: 1 Survey Unit Name: Alaska 

County code and county name

13 Aleutians East Borough 170 Matanuska-Susitna Borough 

16 Aleutians West Census Area 180 Nome Census Area 

20 Anchorage Borough 185 North Slope Borough 

50 Bethel Census Area 188 Northwest Arctic Borough 

60 Bristol Bay Borough 201 Prince of Wales-Outer Ketchikan Census Area 

68 Denali Borough 220 Sitka Borough 

70 Dillingham Census Area 232 Skagway-Hoonah-Angoon Census Area 

90 Fairbanks North Star Borough 240 Southeast Fairbanks Census Area 

100 Haines Borough 261 Valdez-Cordova Census Area 

110 Juneau Borough 270 Wade Hampton Census Area 

122 Kenai Peninsula Borough 280 Wrangell-Petersburg Census Area 

130 Ketchikan Gateway Borough 282 Yakutat Borough 

150 Kodiak Island Borough 290 Yukon-Koyukuk Census Area 

164 Lake and Peninsula Borough 

 

State Code: 4 State Name: Arizona State Abbreviation: AZ Region/Station Code: 22 

Survey Unit Code: 1 Survey Unit Name: Southern 

County code and county name

3 Cochise 12 La Paz 21 Pinal 

9 Graham 13 Maricopa 23 Santa Cruz 

11 Greenlee 19 Pima 27 Yuma 

 

Survey Unit Code: 2 Survey Unit Name: Northern 

County code and county name

1 Apache 7 Gila 17 Navajo 

5 Coconino 15 Mohave 25 Yavapai 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

266 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

State Code: 5 State Name: Arkansas State Abbreviation: AR Region/Station Code: 33 

Survey Unit Code: 1 Survey Unit Name: South Delta 

County code and county name

1 Arkansas 69 Jefferson 85 Lonoke 117 Prairie 

17 Chicot 77 Lee 95 Monroe 

41 Desha 79 Lincoln 107 Phillips 

 

Survey Unit Code: 2 Survey Unit Name: North Delta 

County code and county name

21 Clay 37 Cross 75 Lawrence 123 St. Francis 

31 Craighead 55 Greene 93 Mississippi 147 Woodruff 

35 Crittenden 67 Jackson 111 Poinsett 

 

Survey Unit Code: 3 Survey Unit Name: Southwest 

County code and county name

3 Ashley 27 Columbia 59 Hot Spring 99 Nevada 

11 Bradley 39 Dallas 61 Howard 103 Ouachita 

13 Calhoun 43 Drew 73 Lafayette 109 Pike 

19 Clark 53 Grant 81 Little River 133 Sevier 

25 Cleveland 57 Hempstead 91 Miller 139 Union 

 

Survey Unit Code: 4 Survey Unit Name: Ouachita 

County code and county name

51 Garland 105 Perry 125 Saline 149 Yell 

83 Logan 113 Polk 127 Scott 

97 Montgomery 119 Pulaski 131 Sebastian 

 

Survey Unit Code: 5 Survey Unit Name: Ozark 

County code and county name

5 Baxter 33 Crawford 71 Johnson 129 Searcy 

7 Benton 45 Faulkner 87 Madison 135 Sharp 

9 Boone 47 Franklin 89 Marion 137 Stone 

15 Carroll 49 Fulton 101 Newton 141 Van Buren 

23 Cleburne 63 Independence 115 Pope 143 Washington 

29 Conway 65 Izard 121 Randolph 145 White 

 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 267

State Code: 6 State Name: California State Abbreviation: CA Region/Station Code: 26 

Survey Unit Code: 1 Survey Unit Name: North Coast 

County code and county name

15 Del Norte 23 Humboldt 45 Mendocino 97 Sonoma 

 

Survey Unit Code: 2 Survey Unit Name: North Interior 

County code and county name

35 Lassen 89 Shasta 105 Trinity 

49 Modoc 93 Siskiyou 

 

Survey Unit Code: 3 Survey Unit Name: Sacramento 

County code and county name

7 Butte 33 Lake 63 Plumas 103 Tehama 

11 Colusa 55 Napa 67 Sacramento 113 Yolo 

17 El Dorado 57 Nevada 91 Sierra 115 Yuba 

21 Glenn 61 Placer 101 Sutter 

 

Survey Unit Code: 4 Survey Unit Name: Central Coast 

County code and county name

1 Alameda 69 San Benito 83 Santa Barbara 111 Ventura 

13 Contra Costa 75 San Francisco 85 Santa Clara 

41 Marin 79 San Luis Obispo 87 Santa Cruz 

53 Monterey 81 San Mateo 95 Solano 

 

Survey Unit Code: 5 Survey Unit Name: San Joaquin 

County code and county name

3 Alpine 29 Kern 47 Merced 107 Tulare 

5 Amador 31 Kings 51 Mono 109 Tuolumne 

9 Calaveras 39 Madera 77 San Joaquin 

19 Fresno 43 Mariposa 99 Stanislaus 

 

Survey Unit Code: 6 Survey Unit Name: Southern 

County code and county name

25 Imperial 37 Los Angeles 65 Riverside 73 San Diego 

27 Inyo 59 Orange 71 San Bernardino 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

268 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

State Code: 8 State Name: Colorado State Abbreviation: CO Region/Station Code: 22 

Survey Unit Code: 1 Survey Unit Name: Northern Front Range 

County code and county name

13 Boulder 39 Elbert 59 Jefferson 93 Park 

19 Clear Creek 41 El Paso 65 Lake 119 Teller 

35 Douglas 47 Gilpin 69 Larimer 

 

Survey Unit Code: 2 Survey Unit Name: Southern Front Range 

County code and county name

15 Chaffee 27 Custer 55 Huerfano 101 Pueblo 

23 Costilla 43 Fremont 71 Las Animas 

 

Survey Unit Code: 3 Survey Unit Name: West Central 

County code and county name

3 Alamosa 51 Gunnison 97 Pitkin 111 San Juan 

21 Conejos 53 Hinsdale 105 Rio Grande 117 Summit 

37 Eagle 57 Jackson 107 Routt 

49 Grand 79 Mineral 109 Saguache 

 

Survey Unit Code: 4 Survey Unit Name: Western 

County code and county name

7 Archuleta 45 Garfield 81 Moffat 91 Ouray 

29 Delta 67 La Plata 83 Montezuma 103 Rio Blanco 

33 Dolores 77 Mesa 85 Montrose 113 San Miguel 

 

Survey Unit Code: 5 Survey Unit Name: Eastern 

County code and county name

1 Adams 25 Crowley 75 Logan 115 Sedgwick 

5 Arapahoe 31 Denver 87 Morgan 121 Washington 

9 Baca 61 Kiowa 89 Otero 123 Weld 

11 Bent 63 Kit Carson 95 Phillips 125 Yuma 

17 Cheyenne 73 Lincoln 99 Prowers 

 

State Code: 9 State Name: Connecticut State Abbreviation: CT Region/Station Code: 24 

Survey Unit Code: 1 Survey Unit Name: Connecticut 

County code and county name

1 Fairfield 5 Litchfield 9 New Haven 13 Tolland 

3 Hartford 7 Middlesex 11 New London 15 Windham 

 

State Code: 10 State Name: Delaware State Abbreviation: DE Region/Station Code: 24 

Survey Unit Code: 1 Survey Unit Name: Delaware 

County code and county name

1 Kent 3 New Castle 5 Sussex 

 

State Code: 11 State Name: District of Columbia State Abbrev.: DC Region/Station Code: 24 

 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 269

State Code: 12 State Name: Florida State Abbreviation: FL Region/Station Code: 33 

Survey Unit Code: 1 Survey Unit Name: Northeastern 

County code and county name

1 Alachua 31 Duval 79 Madison 123 Taylor 

3 Baker 35 Flagler 83 Marion 125 Union 

7 Bradford 41 Gilchrist 89 Nassau 127 Volusia 

19 Clay 47 Hamilton 107 Putnam 

23 Columbia 67 Lafayette 109 St. Johns 

29 Dixie 75 Levy 121 Suwannee 

 

Survey Unit Code: 2 Survey Unit Name: Northwestern 

County code and county name

5 Bay 39 Gadsden 65 Jefferson 113 Santa Rosa 

13 Calhoun 45 Gulf 73 Leon 129 Wakulla 

33 Escambia 59 Holmes 77 Liberty 131 Walton 

37 Franklin 63 Jackson 91 Okaloosa 133 Washington 

 

Survey Unit Code: 3 Survey Unit Name: Central 

County code and county name

9 Brevard 55 Highlands 93 Okeechobee 105 Polk 

17 Citrus 57 Hillsborough 95 Orange 111 St. Lucie 

27 DeSoto 61 Indian River 97 Osceola 115 Sarasota 

49 Hardee 69 Lake 101 Pasco 117 Seminole 

53 Hernando 81 Manatee 103 Pinellas 119 Sumter 

 

Survey Unit Code: 4 Survey Unit Name: Southern 

County code and county name

11 Broward 25 Dade 71 Lee 99 Palm Beach 

15 Charlotte 43 Glades 85 Martin 

21 Collier 51 Hendry 87 Monroe 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

270 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

State Code: 13 State Name: Georgia State Abbreviation: GA Region/Station Code: 33 

Survey Unit Code: 1 Survey Unit Name: Southeastern 

County code and county name

1 Appling 51 Chatham 161 Jeff Davis 251 Screven 

3 Atkinson 65 Clinch 165 Jenkins 267 Tattnall 

5 Bacon 69 Coffee 167 Johnson 271 Telfair 

25 Brantley 91 Dodge 175 Laurens 279 Toombs 

29 Bryan 101 Echols 179 Liberty 283 Treutlen 

31 Bulloch 103 Effingham 183 Long 299 Ware 

39 Camden 107 Emanuel 191 McIntosh 305 Wayne 

43 Candler 109 Evans 209 Montgomery 309 Wheeler 

49 Charlton 127 Glynn 229 Pierce 

 

Survey Unit Code: 2 Survey Unit Name: Southwestern 

County code and county name

7 Baker 81 Crisp 173 Lanier 277 Tift 

17 Ben Hill 87 Decatur 185 Lowndes 287 Turner 

19 Berrien 93 Dooly 201 Miller 315 Wilcox 

27 Brooks 99 Early 205 Mitchell 321 Worth 

71 Colquitt 131 Grady 253 Seminole 

75 Cook 155 Irwin 275 Thomas 

 

Survey Unit Code: 3 Survey Unit Name: Central 

County code and county name

9 Baldwin 141 Hancock 211 Morgan 265 Taliaferro 

21 Bibb 145 Harris 215 Muscogee 269 Taylor 

23 Bleckley 153 Houston 225 Peach 273 Terrell 

33 Burke 159 Jasper 231 Pike 289 Twiggs 

35 Butts 163 Jefferson 235 Pulaski 293 Upson 

37 Calhoun 169 Jones 237 Putnam 301 Warren 

53 Chattahoochee 171 Lamar 239 Quitman 303 Washington 

61 Clay 177 Lee 243 Randolph 307 Webster 

73 Columbia 181 Lincoln 245 Richmond 317 Wilkes 

79 Crawford 189 McDuffie 249 Schley 319 Wilkinson 

95 Dougherty 193 Macon 259 Stewart 

125 Glascock 197 Marion 261 Sumter 

133 Greene 207 Monroe 263 Talbot 

 

Survey Unit Code: 4 Survey Unit Name: North Central 

County code and county name

11 Banks 97 Douglas 143 Haralson 219 Oconee 

13 Barrow 105 Elbert 147 Hart 221 Oglethorpe 

45 Carroll 113 Fayette 149 Heard 223 Paulding 

59 Clarke 117 Forsyth 151 Henry 233 Polk 

63 Clayton 119 Franklin 157 Jackson 247 Rockdale 

67 Cobb 121 Fulton 195 Madison 255 Spalding 

77 Coweta 135 Gwinnett 199 Meriwether 285 Troup 

89 DeKalb 139 Hall 217 Newton 297 Walton 

 

 

 

 Georgia cont. 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 271

Georgia cont. 

Survey Unit Code: 5 Survey Unit Name: Northern 

County code and county name

15 Bartow 111 Fannin 213 Murray 295 Walker 

47 Catoosa 115 Floyd 227 Pickens 311 White 

55 Chattooga 123 Gilmer 241 Rabun 313 Whitfield 

57 Cherokee 129 Gordon 257 Stephens 

83 Dade 137 Habersham 281 Towns 

85 Dawson 187 Lumpkin 291 Union 

State Code: 15 State Name: Hawaii State Abbreviation: HI Region/Station Code: 26

County code and county name

1 Hawaii 5 Kalawao 9 Maui 

3 Honolulu 7 Kauai 

 

State Code: 16 State Name: Idaho State Abbreviation: ID Region/Station Code: 22 

Survey Unit Code: 1 Survey Unit Name: Northern 

County code and county name

9 Benewah 35 Clearwater 57 Latah 79 Shoshone 

17 Bonner 49 Idaho 61 Lewis 

21 Boundary 55 Kootenai 69 Nez Perce 

 

Survey Unit Code: 2 Survey Unit Name: Southwestern 

County code and county name

1 Ada 27 Canyon 73 Owyhee 87 Washington 

3 Adams 39 Elmore 75 Payette 

15 Boise 45 Gem 85 Valley 

 

Survey Unit Code: 3 Survey Unit Name: Southeastern 

County code and county name

5 Bannock 25 Camas 43 Fremont 65 Madison 

7 Bear Lake 29 Caribou 47 Gooding 67 Minidoka 

11 Bingham 31 Cassia 51 Jefferson 71 Oneida 

13 Blaine 33 Clark 53 Jerome 77 Power 

19 Bonneville 37 Custer 59 Lemhi 81 Teton 

23 Butte 41 Franklin 63 Lincoln 83 Twin Falls 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

272 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

State Code: 17 State Name: Illinois State Abbreviation: IL Region/Station Code: 23 

Survey Unit Code: 1 Survey Unit Name: Southern 

County code and county name

3 Alexander 69 Hardin 145 Perry 165 Saline 

55 Franklin 77 Jackson 151 Pope 181 Union 

59 Gallatin 87 Johnson 153 Pulaski 193 White 

65 Hamilton 127 Massac 157 Randolph 199 Williamson 

 

Survey Unit Code: 2 Survey Unit Name: Claypan 

County code and county name

5 Bond 47 Edwards 101 Lawrence 163 St. Clair 

13 Calhoun 49 Effingham 117 Macoupin 173 Shelby 

23 Clark 51 Fayette 119 Madison 185 Wabash 

25 Clay 61 Greene 121 Marion 189 Washington 

27 Clinton 79 Jasper 133 Monroe 191 Wayne 

33 Crawford 81 Jefferson 135 Montgomery 

35 Cumberland 83 Jersey 159 Richland 

 

Survey Unit Code: 3 Survey Unit Name: Prairie 

County code and county name

1 Adams 53 Ford 105 Livingston 149 Pike 

7 Boone 57 Fulton 107 Logan 155 Putnam 

9 Brown 63 Grundy 109 McDonough 161 Rock Island 

11 Bureau 67 Hancock 111 McHenry 167 Sangamon 

15 Carroll 71 Henderson 113 McLean 169 Schuyler 

17 Cass 73 Henry 115 Macon 171 Scott 

19 Champaign 75 Iroquois 123 Marshall 175 Stark 

21 Christian 85 Jo Daviess 125 Mason 177 Stephenson 

29 Coles 89 Kane 129 Menard 179 Tazewell 

31 Cook 91 Kankakee 131 Mercer 183 Vermilion 

37 DeKalb 93 Kendall 137 Morgan 187 Warren 

39 De Witt 95 Knox 139 Moultrie 195 Whiteside 

41 Douglas 97 Lake 141 Ogle 197 Will 

43 DuPage 99 La Salle 143 Peoria 201 Winnebago 

45 Edgar 103 Lee 147 Piatt 203 Woodford 

 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 273

State Code: 18 State Name: Indiana State Abbreviation: IN Region/Station Code: 23 

Survey Unit Code: 1 Survey Unit Name: Lower Wabash 

County code and county name

21 Clay 83 Knox 129 Posey 165 Vermillion 

27 Daviess 101 Martin 133 Putnam 167 Vigo 

51 Gibson 121 Parke 153 Sullivan 

55 Greene 125 Pike 163 Vanderburgh 

 

Survey Unit Code: 2 Survey Unit Name: Knobs 

County code and county name

13 Brown 61 Harrison 117 Orange 173 Warrick 

19 Clark 71 Jackson 119 Owen 175 Washington 

25 Crawford 93 Lawrence 123 Perry 

37 Dubois 105 Monroe 143 Scott 

43 Floyd 109 Morgan 147 Spencer 

 

Survey Unit Code: 3 Survey Unit Name: Upland Flats 

County code and county name

29 Dearborn 77 Jefferson 137 Ripley 

41 Fayette 79 Jennings 155 Switzerland 

47 Franklin 115 Ohio 161 Union 

 

Survey Unit Code: 4 Survey Unit Name: Northern 

County code and county name

1 Adams 45 Fountain 87 Lagrange 139 Rush 

3 Allen 49 Fulton 89 Lake 141 St. Joseph 

5 Bartholomew 53 Grant 91 La Porte 145 Shelby 

7 Benton 57 Hamilton 95 Madison 149 Starke 

9 Blackford 59 Hancock 97 Marion 151 Steuben 

11 Boone 63 Hendricks 99 Marshall 157 Tippecanoe 

15 Carroll 65 Henry 103 Miami 159 Tipton 

17 Cass 67 Howard 107 Montgomery 169 Wabash 

23 Clinton 69 Huntington 111 Newton 171 Warren 

31 Decatur 73 Jasper 113 Noble 177 Wayne 

33 De Kalb 75 Jay 127 Porter 179 Wells 

35 Delaware 81 Johnson 131 Pulaski 181 White 

39 Elkhart 85 Kosciusko 135 Randolph 183 Whitley 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

274 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

State Code: 19 State Name: Iowa State Abbreviation: IA Region/Station Code: 23 

Survey Unit Code: 1 Survey Unit Name: Northeastern 

County code and county name

5 Allamakee 31 Cedar 65 Fayette 105 Jones 

11 Benton 37 Chickasaw 67 Floyd 113 Linn 

13 Black Hawk 43 Clayton 75 Grundy 131 Mitchell 

17 Bremer 45 Clinton 89 Howard 163 Scott 

19 Buchanan 55 Delaware 97 Jackson 171 Tama 

23 Butler 61 Dubuque 103 Johnson 191 Winneshiek 

 

Survey Unit Code: 2 Survey Unit Name: Southeastern 

County code and county name

7 Appanoose 83 Hardin 121 Madison 177 Van Buren 

15 Boone 87 Henry 123 Mahaska 179 Wapello 

39 Clarke 95 Iowa 125 Marion 181 Warren 

49 Dallas 99 Jasper 127 Marshall 183 Washington 

51 Davis 101 Jefferson 135 Monroe 185 Wayne 

53 Decatur 107 Keokuk 139 Muscatine 187 Webster 

57 Des Moines 111 Lee 153 Polk 

77 Guthrie 115 Louisa 157 Poweshiek 

79 Hamilton 117 Lucas 169 Story 

 

Survey Unit Code: 3 Survey Unit Name: Southwestern 

County code and county name

1 Adair 47 Crawford 133 Monona 165 Shelby 

3 Adams 71 Fremont 137 Montgomery 173 Taylor 

9 Audubon 73 Greene 145 Page 175 Union 

27 Carroll 85 Harrison 155 Pottawattamie 193 Woodbury 

29 Cass 129 Mills 159 Ringgold 

 

Survey Unit Code: 4 Survey Unit Name: Northwestern 

County code and county name

21 Buena Vista 63 Emmet 119 Lyon 161 Sac 

25 Calhoun 69 Franklin 141 O'Brien 167 Sioux 

33 Cerro Gordo 81 Hancock 143 Osceola 189 Winnebago 

35 Cherokee 91 Humboldt 147 Palo Alto 195 Worth 

41 Clay 93 Ida 149 Plymouth 197 Wright 

59 Dickinson 109 Kossuth 151 Pocahontas 

 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 275

State Code: 20 State Name: Kansas State Abbreviation: KS Region/Station Code: 23 

Survey Unit Code: 1 Survey Unit Name: Northeastern 

County code and county name

5 Atchison 59 Franklin 117 Marshall 177 Shawnee 

13 Brown 61 Geary 121 Miami 197 Wabaunsee 

27 Clay 85 Jackson 131 Nemaha 201 Washington 

41 Dickinson 87 Jefferson 139 Osage 209 Wyandotte 

43 Doniphan 91 Johnson 149 Pottawatomie 

45 Douglas 103 Leavenworth 161 Riley 

 

Survey Unit Code: 2 Survey Unit Name: Southeastern 

County code and county name

1 Allen 21 Cherokee 99 Labette 133 Neosho 

3 Anderson 31 Coffey 107 Linn 205 Wilson 

11 Bourbon 35 Cowley 111 Lyon 207 Woodson 

15 Butler 37 Crawford 115 Marion 

17 Chase 49 Elk 125 Montgomery 

19 Chautauqua 73 Greenwood 127 Morris 

 

Survey Unit Code: 3 Survey Unit Name: Western 

County code and county name

7 Barber 71 Greeley 129 Morton 171 Scott 

9 Barton 75 Hamilton 135 Ness 173 Sedgwick 

23 Cheyenne 77 Harper 137 Norton 175 Seward 

25 Clark 79 Harvey 141 Osborne 179 Sheridan 

29 Cloud 81 Haskell 143 Ottawa 181 Sherman 

33 Comanche 83 Hodgeman 145 Pawnee 183 Smith 

39 Decatur 89 Jewell 147 Phillips 185 Stafford 

47 Edwards 93 Kearny 151 Pratt 187 Stanton 

51 Ellis 95 Kingman 153 Rawlins 189 Stevens 

53 Ellsworth 97 Kiowa 155 Reno 191 Sumner 

55 Finney 101 Lane 157 Republic 193 Thomas 

57 Ford 105 Lincoln 159 Rice 195 Trego 

63 Gove 109 Logan 163 Rooks 199 Wallace 

65 Graham 113 McPherson 165 Rush 203 Wichita 

67 Grant 119 Meade 167 Russell 

69 Gray 123 Mitchell 169 Saline 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

276 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

State Code: 21 State Name: Kentucky State Abbreviation: KY Region/Station Code: 33 

Survey Unit Code: 1 Survey Unit Name: Eastern 

County code and county name

71 Floyd 119 Knott 133 Letcher 193 Perry 

95 Harlan 131 Leslie 159 Martin 195 Pike 

 

Survey Unit Code: 2 Survey Unit Name: Northern Cumberland 

County code and county name

19 Boyd 115 Johnson 165 Menifee 237 Wolfe 

43 Carter 127 Lawrence 175 Morgan 

63 Elliott 135 Lewis 197 Powell 

89 Greenup 153 Magoffin 205 Rowan 

 

Survey Unit Code: 3 Survey Unit Name: Southern Cumberland 

County code and county name

13 Bell 65 Estill 125 Laurel 189 Owsley 

25 Breathitt 109 Jackson 129 Lee 203 Rockcastle 

51 Clay 121 Knox 147 McCreary 235 Whitley 

 

Survey Unit Code: 4 Survey Unit Name: Bluegrass 

County code and county name

5 Anderson 67 Fayette 113 Jessamine 187 Owen 

11 Bath 69 Fleming 117 Kenton 191 Pendleton 

15 Boone 73 Franklin 137 Lincoln 201 Robertson 

17 Bourbon 77 Gallatin 151 Madison 209 Scott 

21 Boyle 79 Garrard 161 Mason 211 Shelby 

23 Bracken 81 Grant 167 Mercer 215 Spencer 

37 Campbell 97 Harrison 173 Montgomery 223 Trimble 

41 Carroll 103 Henry 181 Nicholas 229 Washington 

49 Clark 111 Jefferson 185 Oldham 239 Woodford 

 

Survey Unit Code: 5 Survey Unit Name: Pennyroyal 

County code and county name

1 Adair 57 Cumberland 99 Hart 179 Nelson 

27 Breckinridge 85 Grayson 123 Larue 199 Pulaski 

29 Bullitt 87 Green 155 Marion 207 Russell 

45 Casey 91 Hancock 163 Meade 217 Taylor 

53 Clinton 93 Hardin 169 Metcalfe 231 Wayne 

 

Survey Unit Code: 6 Survey Unit Name: Western Coalfield 

County code and county name

3 Allen 55 Crittenden 141 Logan 213 Simpson 

9 Barren 59 Daviess 149 McLean 219 Todd 

31 Butler 61 Edmonson 171 Monroe 225 Union 

33 Caldwell 101 Henderson 177 Muhlenberg 227 Warren 

47 Christian 107 Hopkins 183 Ohio 233 Webster 

 

Survey Unit Code: 7 Survey Unit Name: Western 

County code and county name

7 Ballard 75 Fulton 139 Livingston 157 Marshall 

35 Calloway 83 Graves 143 Lyon 221 Trigg 

39 Carlisle 105 Hickman 145 McCracken 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 277

State Code: 22 State Name: Louisiana State Abbreviation: LA Region/Station Code: 33 

Survey Unit Code: 1 Survey Unit Name: North Delta 

County code and county name

25 Catahoula 41 Franklin 83 Richland 

29 Concordia 65 Madison 107 Tensas 

35 East Carroll 67 Morehouse 123 West Carroll 

 

Survey Unit Code: 2 Survey Unit Name: South Delta 

County code and county name

1 Acadia 47 Iberville 77 Pointe Coupee 99 St. Martin 

5 Ascension 51 Jefferson 87 St. Bernard 101 St. Mary 

7 Assumption 55 Lafayette 89 St. Charles 109 Terrebonne 

9 Avoyelles 57 Lafourche 93 St. James 113 Vermilion 

23 Cameron 71 Orleans 95 St. John the Baptist 121 West Baton Rouge 

45 Iberia 75 Plaquemines 97 St. Landry 125 West Feliciana 

 

Survey Unit Code: 3 Survey Unit Name: Southwest 

County code and county name

3 Allen 39 Evangeline 59 La Salle 85 Sabine 

11 Beauregard 43 Grant 69 Natchitoches 115 Vernon 

19 Calcasieu 53 Jefferson Davis 79 Rapides 

 

Survey Unit Code: 4 Survey Unit Name: Southeast 

County code and county name

33 East Baton Rouge 63 Livingston 103 St. Tammany 117 Washington 

37 East Feliciana 91 St. Helena 105 Tangipahoa 

 

Survey Unit Code: 5 Survey Unit Name: Northwest 

County code and county name

13 Bienville 27 Claiborne 73 Ouachita 127 Winn 

15 Bossier 31 De Soto 81 Red River 

17 Caddo 49 Jackson 111 Union 

21 Caldwell 61 Lincoln 119 Webster 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

278 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

State Code: 23 State Name: Maine State Abbreviation: ME Region/Station Code: 24 

Survey Unit Code: 1 Survey Unit Name: Washington 

County code and county name

29 Washington 

 

Survey Unit Code: 2 Survey Unit Name: Aroostook 

County code and county name

3 Aroostook 

 

Survey Unit Code: 3 Survey Unit Name: Penobscot 

County code and county name

19 Penobscot 

 

Survey Unit Code: 4 Survey Unit Name: Hancock 

County code and county name

9 Hancock 

 

Survey Unit Code: 5 Survey Unit Name: Piscataquis 

County code and county name

21 Piscataquis 

 

Survey Unit Code: 6 Survey Unit Name: Capitol Region 

County code and county name

11 Kennebec 13 Knox 15 Lincoln 27 Waldo 

 

Survey Unit Code: 7 Survey Unit Name: Somerset 

County code and county name

25 Somerset 

 

Survey Unit Code: 8 Survey Unit Name: Casco Bay 

County code and county name

1 Androscoggin 5 Cumberland 23 Sagadahoc 31 York 

 

Survey Unit Code: 9 Survey Unit Name: Western Maine 

County code and county name

7 Franklin 17 Oxford 

 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 279

State Code: 24 State Name: Maryland State Abbreviation: MD Region/Station Code: 24 

Survey Unit Code: 2 Survey Unit Name: Central 

County code and county name

3 Anne Arundel 15 Cecil 29 Kent 41 Talbot 

5 Baltimore 21 Frederick 31 Montgomery 43 Washington 

11 Caroline 25 Harford 33 Prince George's 510 Baltimore city 

13 Carroll 27 Howard 35 Queen Anne's 

 

Survey Unit Code: 3 Survey Unit Name: Southern 

County code and county name

09 Calvert 17 Charles 37 St. Mary's 

 

Survey Unit Code: 4 Survey Unit Name: Lower Eastern Shore 

County code and county name

19 Dorchester 39 Somerset 45 Wicomico 47 Worcester 

 

Survey Unit Code: 5 Survey Unit Name: Western 

County code and county name

1 Allegany 23 Garrett 

 

State Code: 25 State Name: Massachusetts State Abbreviation: MA Region/Station Code: 24 

Survey Unit Code: 1 Survey Unit Name: Massachusetts 

County code and county name

1 Barnstable 9 Essex 17 Middlesex 25 Suffolk 

3 Berkshire 11 Franklin 19 Nantucket 27 Worcester 

5 Bristol 13 Hampden 21 Norfolk 

7 Dukes 15 Hampshire 23 Plymouth 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

280 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

State Code: 26 State Name: Michigan State Abbreviation: MI Region/Station Code: 23 

Survey Unit Code: 1 Survey Unit Name: Eastern Upper Peninsula 

County code and county name

3 Alger 41 Delta 97 Mackinac 153 Schoolcraft 

33 Chippewa 95 Luce 109 Menominee 

 

Survey Unit Code: 2 Survey Unit Name: Western Upper Peninsula 

County code and county name

13 Baraga 53 Gogebic 71 Iron 103 Marquette 

43 Dickinson 61 Houghton 83 Keweenaw 131 Ontonagon 

 

Survey Unit Code: 3 Survey Unit Name: Northern Lower Peninsula 

County code and county name

1 Alcona 39 Crawford 101 Manistee 133 Osceola 

7 Alpena 47 Emmet 105 Mason 135 Oscoda 

9 Antrim 51 Gladwin 107 Mecosta 137 Otsego 

11 Arenac 55 Grand Traverse 111 Midland 141 Presque Isle 

17 Bay 69 Iosco 113 Missaukee 143 Roscommon 

19 Benzie 73 Isabella 119 Montmorency 165 Wexford 

29 Charlevoix 79 Kalkaska 123 Newaygo 

31 Cheboygan 85 Lake 127 Oceana 

35 Clare 89 Leelanau 129 Ogemaw 

 

Survey Unit Code: 4 Survey Unit Name: Southern Lower Peninsula 

County code and county name

5 Allegan 57 Gratiot 91 Lenawee 147 St. Clair 

15 Barry 59 Hillsdale 93 Livingston 149 St. Joseph 

21 Berrien 63 Huron 99 Macomb 151 Sanilac 

23 Branch 65 Ingham 115 Monroe 155 Shiawassee 

25 Calhoun 67 Ionia 117 Montcalm 157 Tuscola 

27 Cass 75 Jackson 121 Muskegon 159 Van Buren 

37 Clinton 77 Kalamazoo 125 Oakland 161 Washtenaw 

45 Eaton 81 Kent 139 Ottawa 163 Wayne 

49 Genesee 87 Lapeer 145 Saginaw 

 
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State Code: 27 State Name: Minnesota State Abbreviation: MN Region/Station Code: 23 

Survey Unit Code: 1 Survey Unit Name: Aspen-Birch 

County code and county name

17 Carlton 71 Koochiching 137 St. Louis 

31 Cook 75 Lake 

 

Survey Unit Code: 2 Survey Unit Name: Northern Pine 

County code and county name

1 Aitkin 21 Cass 57 Hubbard 87 Mahnomen 

5 Becker 29 Clearwater 61 Itasca 135 Roseau 

7 Beltrami 35 Crow Wing 77 Lake of the Woods 159 Wadena 

 

Survey Unit Code: 3 Survey Unit Name: Central Hardwood 

County code and county name

3 Anoka 49 Goodhue 97 Morrison 141 Sherburne 

9 Benton 53 Hennepin 109 Olmsted 145 Stearns 

19 Carver 55 Houston 111 Otter Tail 153 Todd 

25 Chisago 59 Isanti 115 Pine 157 Wabasha 

37 Dakota 65 Kanabec 123 Ramsey 163 Washington 

41 Douglas 79 Le Sueur 131 Rice 169 Winona 

45 Fillmore 95 Mille Lacs 139 Scott 171 Wright 

 

Survey Unit Code: 4 Survey Unit Name: Prairie 

County code and county name

11 Big Stone 67 Kandiyohi 103 Nicollet 143 Sibley 

13 Blue Earth 69 Kittson 105 Nobles 147 Steele 

15 Brown 73 Lac qui Parle 107 Norman 149 Stevens 

23 Chippewa 81 Lincoln 113 Pennington 151 Swift 

27 Clay 83 Lyon 117 Pipestone 155 Traverse 

33 Cottonwood 85 McLeod 119 Polk 161 Waseca 

39 Dodge 89 Marshall 121 Pope 165 Watonwan 

43 Faribault 91 Martin 125 Red Lake 167 Wilkin 

47 Freeborn 93 Meeker 127 Redwood 173 Yellow Medicine 

51 Grant 99 Mower 129 Renville 

63 Jackson 101 Murray 133 Rock 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

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282 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

State Code: 28 State Name: Mississippi State Abbreviation: MS Region/Station Code: 33 

Survey Unit Code: 1 Survey Unit Name: Delta 

County code and county name

11 Bolivar 55 Issaquena 133 Sunflower 151 Washington 

27 Coahoma 83 Leflore 135 Tallahatchie 163 Yazoo 

51 Holmes 119 Quitman 143 Tunica 

53 Humphreys 125 Sharkey 149 Warren 

 

Survey Unit Code: 2 Survey Unit Name: North 

County code and county name

3 Alcorn 33 DeSoto 95 Monroe 139 Tippah 

9 Benton 43 Grenada 97 Montgomery 141 Tishomingo 

13 Calhoun 57 Itawamba 105 Oktibbeha 145 Union 

15 Carroll 71 Lafayette 107 Panola 155 Webster 

17 Chickasaw 81 Lee 115 Pontotoc 161 Yalobusha 

19 Choctaw 87 Lowndes 117 Prentiss 

25 Clay 93 Marshall 137 Tate 

 

Survey Unit Code: 3 Survey Unit Name: Central 

County code and county name

7 Attala 75 Lauderdale 103 Noxubee 129 Smith 

23 Clarke 79 Leake 121 Rankin 159 Winston 

61 Jasper 99 Neshoba 123 Scott 

69 Kemper 101 Newton 127 Simpson 

 

Survey Unit Code: 4 Survey Unit Name: South 

County code and county name

31 Covington 47 Harrison 77 Lawrence 147 Walthall 

35 Forrest 59 Jackson 91 Marion 153 Wayne 

39 George 65 Jefferson Davis 109 Pearl River 

41 Greene 67 Jones 111 Perry 

45 Hancock 73 Lamar 131 Stone 

 

Survey Unit Code: 5 Survey Unit Name: Southwest 

County code and county name

1 Adams 29 Copiah 63 Jefferson 113 Pike 

5 Amite 37 Franklin 85 Lincoln 157 Wilkinson 

21 Claiborne 49 Hinds 89 Madison 

 
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Appendix C 

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State Code: 29 State Name: Missouri State Abbreviation: MO Region/Station Code: 23 

Survey Unit Code: 1 Survey Unit Name: Eastern Ozarks 

County code and county name

17 Bollinger 65 Dent 179 Reynolds 221 Washington 

23 Butler 93 Iron 181 Ripley 223 Wayne 

35 Carter 123 Madison 187 St. Francois 

55 Crawford 149 Oregon 203 Shannon 

 

Survey Unit Code: 2 Survey Unit Name: Southwestern Ozarks 

County code and county name

9 Barry 91 Howell 153 Ozark 215 Texas 

43 Christian 119 McDonald 209 Stone 225 Webster 

67 Douglas 145 Newton 213 Taney 229 Wright 

 

Survey Unit Code: 3 Survey Unit Name: Northwestern Ozarks 

County code and county name

15 Benton 85 Hickory 141 Morgan 185 St. Clair 

29 Camden 105 Laclede 161 Phelps 

39 Cedar 125 Maries 167 Polk 

59 Dallas 131 Miller 169 Pulaski 

 

Survey Unit Code: 4 Survey Unit Name: Prairie 

County code and county name

1 Adair 53 Cooper 107 Lafayette 171 Putnam 

3 Andrew 57 Dade 109 Lawrence 173 Ralls 

5 Atchison 61 Daviess 111 Lewis 175 Randolph 

7 Audrain 63 DeKalb 113 Lincoln 177 Ray 

11 Barton 75 Gentry 115 Linn 195 Saline 

13 Bates 77 Greene 117 Livingston 197 Schuyler 

21 Buchanan 79 Grundy 121 Macon 199 Scotland 

25 Caldwell 81 Harrison 127 Marion 205 Shelby 

33 Carroll 83 Henry 129 Mercer 211 Sullivan 

37 Cass 87 Holt 137 Monroe 217 Vernon 

41 Chariton 95 Jackson 147 Nodaway 227 Worth 

45 Clark 97 Jasper 159 Pettis 

47 Clay 101 Johnson 163 Pike 

49 Clinton 103 Knox 165 Platte 

 

Survey Unit Code: 5 Survey Unit Name: Riverborder 

County code and county name

19 Boone 73 Gasconade 143 New Madrid 189 St. Louis 

27 Callaway 89 Howard 151 Osage 201 Scott 

31 Cape Girardeau 99 Jefferson 155 Pemiscot 207 Stoddard 

51 Cole 133 Mississippi 157 Perry 219 Warren 

69 Dunklin 135 Moniteau 183 St. Charles 510 St. Louis city 

71 Franklin 139 Montgomery 186 Ste. Genevieve 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

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284 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

State Code: 30 State Name: Montana State Abbreviation: MT Region/Station Code: 22 

Survey Unit Code: 1 Survey Unit Name: Northwestern 

County code and county name

29 Flathead 47 Lake 53 Lincoln 89 Sanders 

 

Survey Unit Code: 2 Survey Unit Name: Eastern 

County code and county name

3 Big Horn 27 Fergus 71 Phillips 95 Stillwater 

5 Blaine 33 Garfield 73 Pondera 97 Sweet Grass 

9 Carbon 35 Glacier 75 Powder River 99 Teton 

11 Carter 37 Golden Valley 79 Prairie 101 Toole 

15 Chouteau 41 Hill 83 Richland 103 Treasure 

17 Custer 51 Liberty 85 Roosevelt 105 Valley 

19 Daniels 55 McCone 87 Rosebud 109 Wibaux 

21 Dawson 65 Musselshell 91 Sheridan 111 Yellowstone 

25 Fallon 69 Petroleum 

 

Survey Unit Code: 3 Survey Unit Name: Western 

County code and county name

39 Granite 61 Mineral 63 Missoula 81 Ravalli 

 

Survey Unit Code: 4 Survey Unit Name: West Central 

County code and county name

7 Broadwater 43 Jefferson 49 Lewis and Clark 77 Powell 

13 Cascade 45 Judith Basin 59 Meagher 107 Wheatland 

 

Survey Unit Code: 5 Survey Unit Name: Southwestern 

County code and county name

1 Beaverhead 31 Gallatin 67 Park 

23 Deer Lodge 57 Madison 93 Silver Bow 

 
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State Code: 31 State Name: Nebraska State Abbreviation: NE Region/Station Code: 23 

Survey Unit Code: 1 Survey Unit Name: Eastern 

County code and county name

1 Adams 55 Douglas 99 Kearney 151 Saline 

11 Boone 59 Fillmore 109 Lancaster 153 Sarpy 

19 Buffalo 61 Franklin 119 Madison 155 Saunders 

21 Burt 63 Frontier 121 Merrick 159 Seward 

23 Butler 65 Furnas 125 Nance 163 Sherman 

25 Cass 67 Gage 127 Nemaha 167 Stanton 

27 Cedar 73 Gosper 129 Nuckolls 169 Thayer 

35 Clay 77 Greeley 131 Otoe 173 Thurston 

37 Colfax 79 Hall 133 Pawnee 175 Valley 

39 Cuming 81 Hamilton 137 Phelps 177 Washington 

41 Custer 83 Harlan 139 Pierce 179 Wayne 

43 Dakota 87 Hitchcock 141 Platte 181 Webster 

47 Dawson 93 Howard 143 Polk 185 York 

51 Dixon 95 Jefferson 145 Red Willow 

53 Dodge 97 Johnson 147 Richardson 

 

Survey Unit Code: 2 Survey Unit Name: Western 

County code and county name

3 Antelope 33 Cheyenne 91 Hooker 123 Morrill 

5 Arthur 45 Dawes 101 Keith 135 Perkins 

7 Banner 49 Deuel 103 Keya Paha 149 Rock 

9 Blaine 57 Dundy 105 Kimball 157 Scotts Bluff 

13 Box Butte 69 Garden 107 Knox 161 Sheridan 

15 Boyd 71 Garfield 111 Lincoln 165 Sioux 

17 Brown 75 Grant 113 Logan 171 Thomas 

29 Chase 85 Hayes 115 Loup 183 Wheeler 

31 Cherry 89 Holt 117 McPherson 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

286 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

State Code: 32 State Name: Nevada State Abbreviation: NV Region/Station Code: 22 

Survey Unit Code: 1 Survey Unit Name: Nevada 

County code and county name

1 Churchill 11 Eureka 21 Mineral 33 White Pine 

3 Clark 13 Humboldt 23 Nye 510 Carson City 

5 Douglas 15 Lander 27 Pershing 

7 Elko 17 Lincoln 29 Storey 

9 Esmeralda 19 Lyon 31 Washoe 

 

State Code: 33 State Name: New Hampshire State Abbreviation: NH Region/Station Code: 24

Survey Unit Code: 2 Survey Unit Name: Northern 

County code and county name

3 Carroll 7 Coos 9 Grafton 

 

Survey Unit Code: 3 Survey Unit Name: Southern 

County code and county name

1 Belknap 11 Hillsborough 15 Rockingham 19 Sullivan 

5 Cheshire 13 Merrimack 17 Strafford 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

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State Code: 34 State Name: New Jersey State Abbreviation: NJ Region/Station Code: 24 

Survey Unit Code: 1 Survey Unit Name: New Jersey 

County code and county name

1 Atlantic 13 Essex 25 Monmouth 37 Sussex 

3 Bergen 15 Gloucester 27 Morris 39 Union 

5 Burlington 17 Hudson 29 Ocean 41 Warren 

7 Camden 19 Hunterdon 31 Passaic 

9 Cape May 21 Mercer 33 Salem 

11 Cumberland 23 Middlesex 35 Somerset 

 

State Code: 35 State Name: New Mexico State Abbreviation: NM Region/Station Code: 22 

Survey Unit Code: 1 Survey Unit Name: Northwestern 

County code and county name

1 Bernalillo 31 McKinley 45 San Juan 61 Valencia 

6 Cibola 39 Rio Arriba 49 Santa Fe 

28 Los Alamos 43 Sandoval 55 Taos 

 

Survey Unit Code: 2 Survey Unit Name: Northeastern 

County code and county name

7 Colfax 21 Harding 37 Quay 57 Torrance 

19 Guadalupe 33 Mora 47 San Miguel 59 Union 

 

Survey Unit Code: 3 Survey Unit Name: Southwestern 

County code and county name

3 Catron 17 Grant 29 Luna 53 Socorro 

13 Dona Ana 23 Hidalgo 51 Sierra 

 

Survey Unit Code: 4 Survey Unit Name: Southeastern 

County code and county name

5 Chaves 11 De Baca 25 Lea 35 Otero 

9 Curry 15 Eddy 27 Lincoln 41 Roosevelt 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

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288 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

State Code: 36 State Name: New York State Abbreviation: NY Region/Station Code: 24 

Survey Unit Code: 1 Survey Unit Name: Adirondack 

County code and county name

19 Clinton 33 Franklin 45 Jefferson 89 St. Lawrence 

 

Survey Unit Code: 2 Survey Unit Name: Lake Plain 

County code and county name

11 Cayuga 53 Madison 69 Ontario 117 Wayne 

29 Erie 55 Monroe 73 Orleans 121 Wyoming 

37 Genesee 63 Niagara 75 Oswego 123 Yates 

51 Livingston 67 Onondaga 99 Seneca 

 

Survey Unit Code: 3 Survey Unit Name: Western Adirondack 

County code and county name

35 Fulton 43 Herkimer 49 Lewis 65 Oneida 

 

Survey Unit Code: 4 Survey Unit Name: Eastern Adirondack 

County code and county name

31 Essex 41 Hamilton 113 Warren 

 

Survey Unit Code: 5 Survey Unit Name: Southwest Highlands 

County code and county name

3 Allegany 9 Cattaraugus 13 Chautauqua 101 Steuben 

 

Survey Unit Code: 6 Survey Unit Name: South-Central Highlands 

County code and county name

7 Broome 23 Cortland 97 Schuyler 

15 Chemung 25 Delaware 107 Tioga 

17 Chenango 77 Otsego 109 Tompkins 

 

Survey Unit Code: 7 Survey Unit Name: Capitol District 

County code and county name

1 Albany 57 Montgomery 91 Saratoga 115 Washington 

21 Columbia 83 Rensselaer 93 Schenectady 

 

Survey Unit Code: 8 Survey Unit Name: Catskill-Lower Hudson 

County code and county name

5 Bronx 59 Nassau 81 Queens 103 Suffolk 

27 Dutchess 61 New York 85 Richmond 105 Sullivan 

39 Greene 71 Orange 87 Rockland 111 Ulster 

47 Kings 79 Putnam 95 Schoharie 119 Westchester 

 
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State Code: 37 State Name: North Carolina State Abbreviation: NC Region/Station Code: 33 

Survey Unit Code: 1 Survey Unit Name: Southern Coastal Plain 

County code and county name

17 Bladen 85 Harnett 125 Moore 163 Sampson 

19 Brunswick 93 Hoke 129 New Hanover 165 Scotland 

47 Columbus 101 Johnston 133 Onslow 191 Wayne 

51 Cumberland 103 Jones 141 Pender 

61 Duplin 105 Lee 153 Richmond 

79 Greene 107 Lenoir 155 Robeson 

 

Survey Unit Code: 2 Survey Unit Name: Northern Coastal Plain 

County code and county name

13 Beaufort 53 Currituck 95 Hyde 143 Perquimans 

15 Bertie 55 Dare 117 Martin 147 Pitt 

29 Camden 65 Edgecombe 127 Nash 177 Tyrrell 

31 Carteret 73 Gates 131 Northampton 187 Washington 

41 Chowan 83 Halifax 137 Pamlico 195 Wilson 

49 Craven 91 Hertford 139 Pasquotank 

 

Survey Unit Code: 3 Survey Unit Name: Piedmont 

County code and county name

1 Alamance 59 Davie 119 Mecklenburg 167 Stanly 

3 Alexander 63 Durham 123 Montgomery 169 Stokes 

7 Anson 67 Forsyth 135 Orange 171 Surry 

25 Cabarrus 69 Franklin 145 Person 179 Union 

33 Caswell 71 Gaston 149 Polk 181 Vance 

35 Catawba 77 Granville 151 Randolph 183 Wake 

37 Chatham 81 Guilford 157 Rockingham 185 Warren 

45 Cleveland 97 Iredell 159 Rowan 197 Yadkin 

57 Davidson 109 Lincoln 161 Rutherford 

 

Survey Unit Code: 4 Survey Unit Name: Mountains 

County code and county name

5 Alleghany 39 Cherokee 111 McDowell 189 Watauga 

9 Ashe 43 Clay 113 Macon 193 Wilkes 

11 Avery 75 Graham 115 Madison 199 Yancey 

21 Buncombe 87 Haywood 121 Mitchell 

23 Burke 89 Henderson 173 Swain 

27 Caldwell 99 Jackson 175 Transylvania 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

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290 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

State Code: 38 State Name: North Dakota State Abbreviation: ND Region/Station Code: 23 

Survey Unit Code: 1 Survey Unit Name: Eastern 

County code and county name

1 Adams 29 Emmons 57 Mercer 85 Sioux 

3 Barnes 31 Foster 59 Morton 87 Slope 

5 Benson 33 Golden Valley 61 Mountrail 89 Stark 

7 Billings 35 Grand Forks 63 Nelson 91 Steele 

9 Bottineau 37 Grant 65 Oliver 93 Stutsman 

11 Bowman 39 Griggs 67 Pembina 95 Towner 

13 Burke 41 Hettinger 69 Pierce 97 Traill 

15 Burleigh 43 Kidder 71 Ramsey 99 Walsh 

17 Cass 45 LaMoure 73 Ransom 101 Ward 

19 Cavalier 47 Logan 75 Renville 103 Wells 

21 Dickey 49 McHenry 77 Richland 105 Williams 

23 Divide 51 McIntosh 79 Rolette 

25 Dunn 53 McKenzie 81 Sargent 

27 Eddy 55 McLean 83 Sheridan 

 
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State Code: 39 State Name: Ohio State Abbreviation: OH Region/Station Code: 24 

Survey Unit Code: 1 Survey Unit Name: South-Central 

County code and county name

1 Adams 53 Gallia 87 Lawrence 145 Scioto 

15 Brown 71 Highland 131 Pike 

25 Clermont 79 Jackson 141 Ross 

 

Survey Unit Code: 2 Survey Unit Name: Southeastern 

County code and county name

9 Athens 105 Meigs 127 Perry 167 Washington 

73 Hocking 115 Morgan 163 Vinton 

 

Survey Unit Code: 3 Survey Unit Name: East-Central 

County code and county name

13 Belmont 59 Guernsey 81 Jefferson 121 Noble 

19 Carroll 67 Harrison 111 Monroe 157 Tuscarawas 

31 Coshocton 75 Holmes 119 Muskingum 

 

Survey Unit Code: 4 Survey Unit Name: Northeastern 

County code and county name

5 Ashland 55 Geauga 103 Medina 155 Trumbull 

7 Ashtabula 77 Huron 133 Portage 169 Wayne 

29 Columbiana 85 Lake 139 Richland 

35 Cuyahoga 93 Lorain 151 Stark 

43 Erie 99 Mahoning 153 Summit 

 

Survey Unit Code: 5 Survey Unit Name: Southwestern 

County code and county name

17 Butler 45 Fairfield 61 Hamilton 113 Montgomery 

23 Clark 47 Fayette 89 Licking 129 Pickaway 

27 Clinton 49 Franklin 97 Madison 135 Preble 

37 Darke 57 Greene 109 Miami 165 Warren 

 

Survey Unit Code: 6 Survey Unit Name: Northwestern 

County code and county name

3 Allen 63 Hancock 107 Mercer 149 Shelby 

11 Auglaize 65 Hardin 117 Morrow 159 Union 

21 Champaign 69 Henry 123 Ottawa 161 Van Wert 

33 Crawford 83 Knox 125 Paulding 171 Williams 

39 Defiance 91 Logan 137 Putnam 173 Wood 

41 Delaware 95 Lucas 143 Sandusky 175 Wyandot 

51 Fulton 101 Marion 147 Seneca 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

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292 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

State Code: 40 State Name: Oklahoma State Abbreviation: OK Region/Station Code: 33 

Survey Unit Code: 1 Survey Unit Name: Southeast 

County code and county name

5 Atoka 29 Coal 79 Le Flore 127 Pushmataha 

13 Bryan 61 Haskell 89 McCurtain 

23 Choctaw 77 Latimer 121 Pittsburg 

 

Survey Unit Code: 2 Survey Unit Name: Northeast 

County code and county name

1 Adair 41 Delaware 97 Mayes 115 Ottawa 

21 Cherokee 91 McIntosh 101 Muskogee 135 Sequoyah 

 

Survey Unit Code: 3 Survey Unit Name: Northcentral 

County code and county name

35 Craig 113 Osage 131 Rogers 145 Wagoner 

37 Creek 117 Pawnee 143 Tulsa 147 Washington 

105 Nowata 119 Payne 

 

Survey Unit Code: 4 Survey Unit Name: Southcentral 

County code and county name

19 Carter 81 Lincoln 95 Marshall 111 Okmulgee 

27 Cleveland 83 Logan 99 Murray 123 Pontotoc 

49 Garvin 85 Love 107 Okfuskee 125 Pottawatomie 

63 Hughes 87 McClain 109 Oklahoma 133 Seminole 

69 Johnston 

 

Survey Unit Code: 5 Survey Unit Name: Southwest 

County code and county name

9 Beckham 33 Cotton 57 Harmon 129 Roger Mills 

11 Blaine 39 Custer 65 Jackson 137 Stephens 

15 Caddo 43 Dewey 67 Jefferson 141 Tillman 

17 Canadian 51 Grady 73 Kingfisher 149 Washita 

31 Comanche 55 Greer 75 Kiowa 

 

Survey Unit Code: 6 Survey Unit Name: High Plains 

County code and county name

7 Beaver 45 Ellis 59 Harper 139 Texas 

25 Cimarron 

 

Survey Unit Code: 7 Survey Unit Name: Great Plains 

County code and county name

3 Alfalfa 53 Grant 93 Major 151 Woods 

47 Garfield 71 Kay 103 Noble 153 Woodward 

 
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Appendix C 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 293

State Code: 41 State Name: Oregon State Abbreviation: OR Region/Station Code: 26 

Survey Unit Code: 0 Survey Unit Name: Northwest 

County code and county name

5 Clackamas 27 Hood River 53 Polk 71 Yamhill 

7 Clatsop 47 Marion 57 Tillamook 

9 Columbia 51 Multnomah 67 Washington 

 

Survey Unit Code: 1 Survey Unit Name: West Central 

County code and county name

3 Benton 39 Lane 41 Lincoln 43 Linn 

 

Survey Unit Code: 2 Survey Unit Name: Southwest 

County code and county name

11 Coos 19 Douglas 33 Josephine 

15 Curry 29 Jackson 

 

Survey Unit Code: 3 Survey Unit Name: Central 

County code and county name

13 Crook 31 Jefferson 55 Sherman 

17 Deschutes 35 Klamath 65 Wasco 

21 Gilliam 37 Lake 69 Wheeler 

 

Survey Unit Code: 4 Survey Unit Name: Blue Mountains 

County code and county name

1 Baker 25 Harney 49 Morrow 61 Union 

23 Grant 45 Malheur 59 Umatilla 63 Wallowa 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

294 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

State Code: 42 State Name: Pennsylvania State Abbreviation: PA Region/Station Code: 24 

Survey Unit Code: 0 Survey Unit Name: South Central 

County code and county name

43 Dauphin 61 Huntingdon 99 Perry 

55 Franklin 67 Juniata 109 Snyder 

57 Fulton 87 Mifflin 119 Union 

 

Survey Unit Code: 5 Survey Unit Name: Western 

County code and county name

3 Allegheny 19 Butler 59 Greene 85 Mercer 

5 Armstrong 39 Crawford 63 Indiana 125 Washington 

7 Beaver 49 Erie 73 Lawrence 129 Westmoreland 

 

Survey Unit Code: 6 Survey Unit Name: North Central/Allegheny 

County code and county name

23 Cameron 35 Clinton 81 Lycoming 117 Tioga 

27 Centre 47 Elk 83 McKean 121 Venango 

31 Clarion 53 Forest 105 Potter 123 Warren 

33 Clearfield 65 Jefferson 113 Sullivan 

 

Survey Unit Code: 7 Survey Unit Name: Southwestern 

County code and county name

9 Bedford 21 Cambria 111 Somerset 

13 Blair 51 Fayette 

 

Survey Unit Code: 8 Survey Unit Name: Northeastern/Pocono 

County code and county name

15 Bradford 79 Luzerne 103 Pike 131 Wyoming 

25 Carbon 89 Monroe 107 Schuylkill 

37 Columbia 93 Montour 115 Susquehanna 

69 Lackawanna 97 Northumberland 127 Wayne 

 

Survey Unit Code: 9 Survey Unit Name: Southeastern 

County code and county name

1 Adams 41 Cumberland 77 Lehigh 133 York 

11 Berks 45 Delaware 91 Montgomery 

17 Bucks 71 Lancaster 95 Northampton 

29 Chester 75 Lebanon 101 Philadelphia 

 

State Code: 44 State Name: Rhode Island State Abbreviation: RI Region/Station Code: 24 

Survey Unit Code: 1 Survey Unit Name: Rhode Island 

County code and county name

1 Bristol 5 Newport 9 Washington 

3 Kent 7 Providence 

 
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Appendix C 

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State Code: 45 State Name: South Carolina State Abbreviation: SC Region/Station Code: 33 

Survey Unit Code: 1 Survey Unit Name: Southern Coastal Plain 

County code and county name

3 Aiken 11 Barnwell 29 Colleton 53 Jasper 

5 Allendale 13 Beaufort 35 Dorchester 63 Lexington 

9 Bamberg 17 Calhoun 49 Hampton 75 Orangeburg 

 

Survey Unit Code: 2 Survey Unit Name: Northern Coastal Plain 

County code and county name

15 Berkeley 31 Darlington 51 Horry 69 Marlboro 

19 Charleston 33 Dillon 55 Kershaw 79 Richland 

25 Chesterfield 41 Florence 61 Lee 85 Sumter 

27 Clarendon 43 Georgetown 67 Marion 89 Williamsburg 

 

Survey Unit Code: 3 Survey Unit Name: Piedmont 

County code and county name

1 Abbeville 39 Fairfield 65 McCormick 83 Spartanburg 

7 Anderson 45 Greenville 71 Newberry 87 Union 

21 Cherokee 47 Greenwood 73 Oconee 91 York 

23 Chester 57 Lancaster 77 Pickens 

37 Edgefield 59 Laurens 81 Saluda 

 

State Code: 46 State Name: South Dakota State Abbreviation: SD Region/Station Code: 23 

Survey Unit Code: 1 Survey Unit Name: Eastern 

County code and county name

3 Aurora 37 Day 71 Jackson 107 Potter 

5 Beadle 39 Deuel 73 Jerauld 109 Roberts 

7 Bennett 41 Dewey 75 Jones 111 Sanborn 

9 Bon Homme 43 Douglas 77 Kingsbury 115 Spink 

11 Brookings 45 Edmunds 79 Lake 117 Stanley 

13 Brown 49 Faulk 83 Lincoln 119 Sully 

15 Brule 51 Grant 85 Lyman 121 Todd 

17 Buffalo 53 Gregory 87 McCook 123 Tripp 

21 Campbell 55 Haakon 89 McPherson 125 Turner 

23 Charles Mix 57 Hamlin 91 Marshall 127 Union 

25 Clark 59 Hand 95 Mellette 129 Walworth 

27 Clay 61 Hanson 97 Miner 135 Yankton 

29 Codington 65 Hughes 99 Minnehaha 137 Ziebach 

31 Corson 67 Hutchinson 101 Moody 

35 Davison 69 Hyde 105 Perkins 

 

Survey Unit Code: 2 Survey Unit Name: Western 

County code and county name

19 Butte 47 Fall River 81 Lawrence 103 Pennington 

33 Custer 63 Harding 93 Meade 113 Shannon 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

296 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

State Code: 47 State Name: Tennessee State Abbreviation: TN Region/Station Code: 33 

Survey Unit Code: 1 Survey Unit Name: West 

County code and county name

17 Carroll 53 Gibson 95 Lake 157 Shelby 

23 Chester 69 Hardeman 97 Lauderdale 167 Tipton 

33 Crockett 75 Haywood 109 McNairy 183 Weakley 

45 Dyer 77 Henderson 113 Madison 

47 Fayette 79 Henry 131 Obion 

 

Survey Unit Code: 2 Survey Unit Name: West Central 

County code and county name

5 Benton 81 Hickman 99 Lawrence 161 Stewart 

39 Decatur 83 Houston 101 Lewis 181 Wayne 

71 Hardin 85 Humphreys 135 Perry 

 

Survey Unit Code: 3 Survey Unit Name: Central 

County code and county name

3 Bedford 41 DeKalb 117 Marshall 159 Smith 

15 Cannon 43 Dickson 119 Maury 165 Sumner 

21 Cheatham 55 Giles 125 Montgomery 169 Trousdale 

27 Clay 87 Jackson 127 Moore 187 Williamson 

31 Coffee 103 Lincoln 147 Robertson 189 Wilson 

37 Davidson 111 Macon 149 Rutherford 

 

Survey Unit Code: 4 Survey Unit Name: Plateau 

County code and county name

7 Bledsoe 51 Franklin 133 Overton 153 Sequatchie 

13 Campbell 61 Grundy 137 Pickett 175 Van Buren 

35 Cumberland 115 Marion 141 Putnam 177 Warren 

49 Fentress 129 Morgan 151 Scott 185 White 

 

Survey Unit Code: 5 Survey Unit Name: East 

County code and county name

1 Anderson 59 Greene 93 Knox 145 Roane 

9 Blount 63 Hamblen 105 Loudon 155 Sevier 

11 Bradley 65 Hamilton 107 McMinn 163 Sullivan 

19 Carter 67 Hancock 121 Meigs 171 Unicoi 

25 Claiborne 73 Hawkins 123 Monroe 173 Union 

29 Cocke 89 Jefferson 139 Polk 179 Washington 

57 Grainger 91 Johnson 143 Rhea 

 
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Appendix C 

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State Code: 48 State Name: Texas State Abbreviation: TX Region/Station Code: 33 

Survey Unit Code: 1 Survey Unit Name: Southeast 

County code and county name

5 Angelina 241 Jasper 351 Newton 455 Trinity 

71 Chambers 245 Jefferson 361 Orange 457 Tyler 

185 Grimes 289 Leon 373 Polk 471 Walker 

199 Hardin 291 Liberty 403 Sabine 473 Waller 

201 Harris 313 Madison 405 San Augustine 

225 Houston 339 Montgomery 407 San Jacinto 

 

Survey Unit Code: 2 Survey Unit Name: Northeast 

County code and county name

1 Anderson 183 Gregg 365 Panola 459 Upshur 

37 Bowie 203 Harrison 387 Red River 467 Van Zandt 

63 Camp 213 Henderson 401 Rusk 499 Wood 

67 Cass 315 Marion 419 Shelby 

73 Cherokee 343 Morris 423 Smith 

159 Franklin 347 Nacogdoches 449 Titus 

 

Survey Unit Code: 3 Survey Unit Name: Northcentral 

County code and county name

15 Austin 121 Denton 217 Hill 337 Montague 

21 Bastrop 123 De Witt 223 Hopkins 349 Navarro 

41 Brazos 139 Ellis 231 Hunt 367 Parker 

51 Burleson 145 Falls 237 Jack 379 Rains 

55 Caldwell 147 Fannin 251 Johnson 395 Robertson 

77 Clay 149 Fayette 257 Kaufman 397 Rockwall 

85 Collin 161 Freestone 277 Lamar 439 Tarrant 

89 Colorado 175 Goliad 285 Lavaca 477 Washington 

97 Cooke 177 Gonzales 287 Lee 497 Wise 

113 Dallas 181 Grayson 293 Limestone 503 Young 

119 Delta 187 Guadalupe 331 Milam 

 

Survey Unit Code: 4 Survey Unit Name: South 

County code and county name

7 Aransas 157 Fort Bend 273 Kleberg 427 Starr 

13 Atascosa 163 Frio 283 La Salle 469 Victoria 

25 Bee 167 Galveston 297 Live Oak 479 Webb 

39 Brazoria 215 Hidalgo 311 McMullen 481 Wharton 

47 Brooks 239 Jackson 321 Matagorda 489 Willacy 

57 Calhoun 247 Jim Hogg 323 Maverick 493 Wilson 

61 Cameron 249 Jim Wells 355 Nueces 505 Zapata 

127 Dimmit 255 Karnes 391 Refugio 507 Zavala 

131 Duval 261 Kenedy 409 San Patricio 

 Texas cont. 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

298 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Texas cont. 

Survey Unit Code: 5 Survey Unit Name: Westcentral 

County code and county name

19 Bandera 99 Coryell 267 Kimble 385 Real 

27 Bell 105 Crockett 271 Kinney 399 Runnels 

29 Bexar 133 Eastland 281 Lampasas 411 San Saba 

31 Blanco 137 Edwards 299 Llano 413 Schleicher 

35 Bosque 143 Erath 307 McCulloch 425 Somervell 

49 Brown 171 Gillespie 309 McLennan 429 Stephens 

53 Burnet 193 Hamilton 319 Mason 435 Sutton 

59 Callahan 209 Hays 325 Medina 453 Travis 

83 Coleman 221 Hood 327 Menard 463 Uvalde 

91 Comal 259 Kendall 333 Mills 465 Val Verde 

93 Comanche 265 Kerr 363 Palo Pinto 491 Williamson 

95 Concho 

 

Survey Unit Code: 6 Survey Unit Name: Northwest 

County code and county name

3 Andrews 129 Donley 235 Irion 375 Potter 

9 Archer 151 Fisher 253 Jones 381 Randall 

11 Armstrong 153 Floyd 263 Kent 383 Reagan 

17 Bailey 155 Foard 269 King 393 Roberts 

23 Baylor 165 Gaines 275 Knox 415 Scurry 

33 Borden 169 Garza 279 Lamb 417 Shackelford 

45 Briscoe 173 Glasscock 295 Lipscomb 421 Sherman 

65 Carson 179 Gray 303 Lubbock 431 Sterling 

69 Castro 189 Hale 305 Lynn 433 Stonewall 

75 Childress 191 Hall 317 Martin 437 Swisher 

79 Cochran 195 Hansford 329 Midland 441 Taylor 

81 Coke 197 Hardeman 335 Mitchell 445 Terry 

87 Collingsworth 205 Hartley 341 Moore 447 Throckmorton 

101 Cottle 207 Haskell 345 Motley 451 Tom Green 

107 Crosby 211 Hemphill 353 Nolan 483 Wheeler 

111 Dallam 219 Hockley 357 Ochiltree 485 Wichita 

115 Dawson 227 Howard 359 Oldham 487 Wilbarger 

117 Deaf Smith 233 Hutchinson 369 Parmer 501 Yoakum 

125 Dickens 

 

Survey Unit Code: 7 Survey Unit Name: West 

County code and county name

43 Brewster 141 El Paso 371 Pecos 461 Upton 

103 Crane 229 Hudsbeth 377 Presidio 475 Ward 

109 Culberson 243 Jeff Davis 389 Reeves 495 Winkler 

135 Ector 301 Loving 443 Terrell 

 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 299

State Code: 49 State Name: Utah State Abbreviation: UT Region/Station Code: 22 

Survey Unit Code: 1 Survey Unit Name: Northern 

County code and county name

3 Box Elder 29 Morgan 43 Summit 51 Wasatch 

5 Cache 33 Rich 45 Tooele 57 Weber 

11 Davis 35 Salt Lake 49 Utah 

 

Survey Unit Code: 2 Survey Unit Name: Uinta 

County code and county name

9 Daggett 13 Duchesne 47 Uintah 

 

Survey Unit Code: 3 Survey Unit Name: Central 

County code and county name

23 Juab 31 Piute 41 Sevier 

27 Millard 39 Sanpete 55 Wayne 

 

Survey Unit Code: 4 Survey Unit Name: Eastern 

County code and county name

7 Carbon 15 Emery 19 Grand 37 San Juan 

 

Survey Unit Code: 5 Survey Unit Name: Southwestern 

County code and county name

1 Beaver 21 Iron 53 Washington 

17 Garfield 25 Kane 

 

State Code: 50 State Name: Vermont State Abbreviation: VT Region/Station Code: 24 

Survey Unit Code: 2 Survey Unit Name: Northern 

County code and county name

5 Caledonia 11 Franklin 15 Lamoille 19 Orleans 

9 Essex 13 Grand Isle 17 Orange 23 Washington 

 

Survey Unit Code: 3 Survey Unit Name: Southern 

County code and county name

1 Addison 7 Chittenden 25 Windham 

3 Bennington 21 Rutland 27 Windsor 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

300 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

State Code: 51 State Name: Virginia State Abbreviation: VA Region/Station Code: 33 

Survey Unit Code: 1 Survey Unit Name: Coastal Plain 

County code and county name

1 Accomack 85 Hanover 119 Middlesex 193 Westmoreland 

25 Brunswick 87 Henrico 127 New Kent 199 York 

33 Caroline 93 Isle Of Wight 131 Northampton 550 Chesapeake city 

36 Charles City 95 James City 133 Northumberland 650 Hampton city 

41 Chesterfield 97 King And Queen 149 Prince George 700 Newport News city 

53 Dinwiddie 99 King George 159 Richmond 800 Suffolk city 

57 Essex 101 King William 175 Southampton 810 Virginia Beach city 

73 Gloucester 103 Lancaster 181 Surry 

81 Greensville 115 Mathews 183 Sussex 

 

Survey Unit Code: 2 Survey Unit Name: Southern Piedmont 

County code and county name

7 Amelia 37 Charlotte 111 Lunenburg 145 Powhatan 

11 Appomattox 49 Cumberland 117 Mecklenburg 147 Prince Edward 

19 Bedford 67 Franklin 135 Nottoway 

29 Buckingham 83 Halifax 141 Patrick 

31 Campbell 89 Henry 143 Pittsylvania 

 

Survey Unit Code: 3 Survey Unit Name: Northern Piedmont 

County code and county name

3 Albemarle 61 Fauquier 109 Louisa 157 Rappahannock 

9 Amherst 65 Fluvanna 113 Madison 177 Spotsylvania 

13 Arlington 75 Goochland 125 Nelson 179 Stafford 

47 Culpeper 79 Greene 137 Orange 

59 Fairfax 107 Loudoun 153 Prince William 

 

Survey Unit Code: 4 Survey Unit Name: Northern Mountains 

County code and county name

5 Alleghany 43 Clarke 139 Page 171 Shenandoah 

15 Augusta 45 Craig 161 Roanoke 187 Warren 

17 Bath 69 Frederick 163 Rockbridge 

23 Botetourt 91 Highland 165 Rockingham 

 

Survey Unit Code: 5 Survey Unit Name: Southern Mountains 

County code and county name

21 Bland 71 Giles 167 Russell 195 Wise 

27 Buchanan 77 Grayson 169 Scott 197 Wythe 

35 Carroll 105 Lee 173 Smyth 

51 Dickenson 121 Montgomery 185 Tazewell 

63 Floyd 155 Pulaski 191 Washington 

 

 Virginia cont. 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 301

Virginia cont. 

Cities aggregated into other counties

City code and city name 

Associated county code 

and county name City code and city name 

Associated county code and 

county name 

510 Alexandria city 59 Fairfax 683 Manassas city 153 Prince William 

515 Bedford city 19 Bedford 685 Manassas Park city 153 Prince William 

520 Bristol city 191 Washington 690 Martinsville city 89 Henry 

530 Buena Vista city 163 Rockbridge 710 Norfolk city 550 Chesapeake City 

540 Charlottesville city 3 Albemarle 720 Norton city 195 Wise 

560 Clifton Forge city 5 Allegheny 730 Petersburg city 53 Dinwiddie 

570 Colonial Heights city 41 Chesterfield 730 Petersburg city 149 Prince George 

580 Covington city 5 Allegheny 735 Poquoson city 199 York 

590 Danville city 143 Pittsylvania 740 Portsmouth city 550 Chesapeake City 

595 Emporia city 81 Greensville 750 Radford city 121 Montgomery 

600 Fairfax city 59 Fairfax 760 Richmond city 41 Chesterfield 

610 Falls Church city 59 Fairfax 760 Richmond city 87 Henrico 

620 Franklin city 175 Southampton 770 Roanoke city 161 Roanoke 

630 Fredericksburg city 177 Spotsylvania 775 Salem city 161 Roanoke 

640 Galax city 35 Carroll 780 South Boston city 83 Halifax 

640 Galax city 77 Grayson 790 Staunton city 15 Augusta 

660 Harrisonburg city 165 Rockingham 820 Waynesboro city 15 Augusta 

670 Hopewell city 149 Prince George 830 Williamsburg city 95 County of James City 

678 Lexington city 163 Rockbridge 840 Winchester city 69 Frederick 

680 Lynchburg city 31 Campbell 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

302 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

State Code: 53 State Name: Washington State Abbreviation: WA Region/Station Code: 26 

Survey Unit Code: 5 Survey Unit Name: Puget Sound 

County code and county name

29 Island 35 Kitsap 55 San Juan 61 Snohomish 

33 King 53 Pierce 57 Skagit 73 Whatcom 

 

Survey Unit Code: 6 Survey Unit Name: Olympic Peninsula 

County code and county name

9 Clallam 31 Jefferson 67 Thurston 

27 Grays Harbor 45 Mason 

 

Survey Unit Code: 7 Survey Unit Name: Southwest 

County code and county name

11 Clark 41 Lewis 59 Skamania 

15 Cowlitz 49 Pacific 69 Wahkiakum 

 

Survey Unit Code: 8 Survey Unit Name: Central 

County code and county name

7 Chelan 37 Kittitas 47 Okanogan 

17 Douglas 39 Klickitat 77 Yakima 

 

Survey Unit Code: 9 Survey Unit Name: Inland Empire 

County code and county name

1 Adams 19 Ferry 43 Lincoln 71 Walla Walla 

3 Asotin 21 Franklin 51 Pend Oreille 75 Whitman 

5 Benton 23 Garfield 63 Spokane 

13 Columbia 25 Grant 65 Stevens 

 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 303

State Code: 54 State Name: West Virginia State Abbreviation: WV Region/Station Code: 24 

Survey Unit Code: 2 Survey Unit Name: Northeastern 

County code and county name

1 Barbour 31 Hardy 65 Morgan 91 Taylor 

3 Berkeley 33 Harrison 71 Pendleton 93 Tucker 

7 Braxton 37 Jefferson 75 Pocahontas 97 Upshur 

23 Grant 41 Lewis 77 Preston 101 Webster 

27 Hampshire 57 Mineral 83 Randolph 

 

Survey Unit Code: 3 Survey Unit Name: Southern 

County code and county name

5 Boone 39 Kanawha 59 Mingo 89 Summers 

15 Clay 45 Logan 63 Monroe 109 Wyoming 

19 Fayette 47 McDowell 67 Nicholas 

25 Greenbrier 55 Mercer 81 Raleigh 

 

Survey Unit Code: 4 Survey Unit Name: Northwestern 

County code and county name

9 Brooke 35 Jackson 69 Ohio 99 Wayne 

11 Cabell 43 Lincoln 73 Pleasants 103 Wetzel 

13 Calhoun 49 Marion 79 Putnam 105 Wirt 

17 Doddridge 51 Marshall 85 Ritchie 107 Wood 

21 Gilmer 53 Mason 87 Roane 

29 Hancock 61 Monongalia 95 Tyler 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

304 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

State Code: 55 State Name: Wisconsin State Abbreviation: WI Region/Station Code: 23 

Survey Unit Code: 1 Survey Unit Name: Northeastern 

County code and county name

37 Florence 69 Lincoln 83 Oconto 125 Vilas 

41 Forest 75 Marinette 85 Oneida 

67 Langlade 78 Menominee 115 Shawano 

 

Survey Unit Code: 2 Survey Unit Name: Northwestern 

County code and county name

3 Ashland 13 Burnett 95 Polk 113 Sawyer 

5 Barron 31 Douglas 99 Price 119 Taylor 

7 Bayfield 51 Iron 107 Rusk 129 Washburn 

 

Survey Unit Code: 3 Survey Unit Name: Central 

County code and county name

1 Adams 53 Jackson 81 Monroe 141 Wood 

17 Chippewa 57 Juneau 97 Portage 

19 Clark 73 Marathon 135 Waupaca 

35 Eau Claire 77 Marquette 137 Waushara 

 

Survey Unit Code: 4 Survey Unit Name: Southwestern 

County code and county name

11 Buffalo 49 Iowa 93 Pierce 121 Trempealeau 

23 Crawford 63 La Crosse 103 Richland 123 Vernon 

33 Dunn 65 Lafayette 109 St. Croix 

43 Grant 91 Pepin 111 Sauk 

 

Survey Unit Code: 5 Survey Unit Name: Southeastern 

County code and county name

9 Brown 39 Fond du Lac 71 Manitowoc 117 Sheboygan 

15 Calumet 45 Green 79 Milwaukee 127 Walworth 

21 Columbia 47 Green Lake 87 Outagamie 131 Washington 

25 Dane 55 Jefferson 89 Ozaukee 133 Waukesha 

27 Dodge 59 Kenosha 101 Racine 139 Winnebago 

29 Door 61 Kewaunee 105 Rock 

 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix C 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 305

State Code: 56 State Name: Wyoming State Abbreviation: WY Region/Station Code: 22 

Survey Unit Code: 1 Survey Unit Name: Western 

County code and county name

13 Fremont 23 Lincoln 35 Sublette 39 Teton 

17 Hot Springs 29 Park 37 Sweetwater 41 Uinta 

 

Survey Unit Code: 2 Survey Unit Name: Central and Southeastern 

County code and county name

1 Albany 9 Converse 21 Laramie 31 Platte 

3 Big Horn 15 Goshen 25 Natrona 33 Sheridan 

7 Carbon 19 Johnson 27 Niobrara 43 Washakie 

 

Survey Unit Code: 3 Survey Unit Name: Northeastern 

County code and county name

5 Campbell 11 Crook 45 Weston 

 

State Code: 72 State Name: Puerto Rico State Abbreviation: PR Region/Station Code: 33 

Survey Unit Code: 1 Survey Unit Name: Puerto Rico

County code and county name

1 Adjuntas 41 Cidra 79 Lajas 119 Rio Grande 

3 Aguada 43 Coamo 81 Lares 121 Sabana Grande 

5 Aguadilla 45 Comerio 83 Las Marias 123 Salinas 

7 Aguas Buenas 47 Corozal 85 Las Piedras 125 San German 

9 Aibonito 49 Culebra 87 Loiza 127 San Juan 

11 Anasco 51 Dorado 89 Luquillo 129 San Lorenzo 

13 Arecibo 53 Fajardo 91 Manati 131 San Sebastian 

15 Arroyo 54 Florida 93 Maricao 133 Santa Isabel 

17 Barceloneta 55 Guanica 95 Maunabo 135 Toa Alta 

19 Barranquitas 57 Guayama 97 Mayaguez 137 Toa Baja 

21 Bayamon 59 Guayanilla 99 Moca 139 Trujillo Alto 

23 Cabo Rojo 61 Guaynabo 101 Morovis 141 Utuado 

25 Caguas 63 Gurabo 103 Naguabo 143 Vega Alta 

27 Camuy 65 Hatillo 105 Naranjito 145 Vega Baja 

29 Canovanas 67 Hormigueros 107 Orocovis 147 Vieques 

31 Carolina 69 Humacao 109 Patillas 149 Villalba 

33 Catano 71 Isabela Municipio 111 Penuelas 151 Yabucoa 

35 Cayey 73 Jayuya 113 Ponce 153 Yauco 

37 Ceiba 75 Juana Diaz 115 Quebradillas 

39 Ciales 77 Juncos 117 Rincon 

 

State Code: 78 State Name: U.S. Virgin Islands State Abbreviation: VI Region/Station Code: 33

Survey Unit Code: 1 Survey Unit Name: Virgin Islands

County code and county name

10 St. Croix Island 20 St. John Island 30 St. Thomas Island 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix D 

306 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Appendix D. Forest Type Codes and Names 

Note: The forest type names used by FIA do not come from a single published reference. The 

current list of forest type names has been developed over time using sources such as historical FIA 

lists, lists from the Society of American Foresters, and FIA analysts who developed names to meet 

current analysis and reporting needs. 

Code Forest type / type group 

100 White / red / jack pine group 

101 Jack pine 

102 Red pine 

103 Eastern white pine 

104 Eastern white pine / eastern hemlock 

105 Eastern hemlock 

 

120 Spruce / fir group 

121 Balsam fir 

122 White spruce 

123 Red spruce 

124 Red spruce / balsam fir 

125 Black spruce 

126 Tamarack 

127 Northern white-cedar 

128 Fraser fir 

129 Red spruce / Fraser fir 

 

140 Longleaf / slash pine group 

141 Longleaf pine 

142 Slash pine 

 

150 Tropical pine group 

151 Tropical pines 

 

160 Loblolly / shortleaf pine group 

161 Loblolly pine 

162 Shortleaf pine 

163 Virginia pine 

164 Sand pine 

165 Table mountain pine 

166 Pond pine 

167 Pitch pine 

168 Spruce pine 

 

170 Other eastern softwoods group 

171 Eastern redcedar 

172 Florida softwoods 

 

180 Pinyon / juniper group 

182 Rocky Mountain juniper 

184 Juniper woodland 

185 Pinyon / juniper woodland 

 

200 Douglas-fir group 

201 Douglas-fir 

202 Port-Orford-cedar 

203 Bigcone Douglas-fir 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix D 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 307

Code Forest type / type group 

220 Ponderosa pine group 

221 Ponderosa pine 

222 Incense-cedar 

224 Sugar pine 

225 Jeffrey pine 

226 Coulter pine 

 

240 Western white pine group 

241 Western white pine 

 

260 Fir / spruce / mountain hemlock group 

261 White fir 

262 Red fir 

263 Noble fir 

264 Pacific silver fir 

265 Engelmann spruce 

266 Engelmann spruce / subalpine fir 

267 Grand fir 

268 Subalpine fir 

269 Blue spruce 

270 Mountain hemlock 

271 Alaska-yellow-cedar 

 

280 Lodgepole pine group 

281 Lodgepole pine 

 

300 Hemlock / Sitka spruce group 

301 Western hemlock 

304 Western redcedar 

305 Sitka spruce 

 

320 Western larch group 

321 Western larch 

 

340 Redwood group 

341 Redwood 

342 Giant sequoia 

 

360 Other western softwoods group 

361 Knobcone pine 

362 Southwestern white pine 

363 Bishop pine 

364 Monterey pine 

365 Foxtail pine / bristlecone pine 

366 Limber pine 

367 Whitebark pine 

368 Miscellaneous western softwoods 

369 Western juniper 

 

370 California mixed conifer group 

371 California mixed conifer 

 

380 Exotic softwoods group 

381 Scotch pine 

383 Other exotic softwoods 

384 Norway spruce 

385 Introduced larch 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix D 

308 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Code Forest type / type group 

390 Other softwoods group 

391 Other softwoods 

 

400 Oak / pine group 

401 Eastern white pine / northern red oak / white ash 

402 Eastern redcedar / hardwood 

403 Longleaf pine / oak 

404 Shortleaf pine / oak 

405 Virginia pine / southern red oak 

406 Loblolly pine / hardwood 

407 Slash pine / hardwood 

409 Other pine / hardwood 

 

500 Oak / hickory group 

501 Post oak / blackjack oak 

502 Chestnut oak 

503 White oak / red oak / hickory 

504 White oak 

505 Northern red oak 

506 Yellow-poplar / white oak / northern red oak 

507 Sassafras / persimmon 

508 Sweetgum / yellow-poplar 

509 Bur oak 

510 Scarlet oak 

511 Yellow-poplar 

512 Black walnut 

513 Black locust 

514 Southern scrub oak 

515 Chestnut oak / black oak / scarlet oak 

516 Cherry / white ash / yellow-poplar 

517 Elm / ash / black locust 

519 Red maple / oak 

520 Mixed upland hardwoods 

 

600 Oak / gum / cypress group 

601 Swamp chestnut oak / cherrybark oak 

602 Sweetgum / Nuttall oak / willow oak 

605 Overcup oak / water hickory 

606 Atlantic white-cedar 

607 Baldcypress / water tupelo 

608 Sweetbay / swamp tupelo / red maple 

609 Baldcypress / pondcypress 

 

700 Elm / ash / cottonwood group 

701 Black ash / American elm / red maple 

702 River birch / sycamore 

703 Cottonwood 

704 Willow 

705 Sycamore / pecan / American elm 

706 Sugarberry / hackberry / elm / green ash 

707 Silver maple / American elm 

708 Red maple / lowland 

709 Cottonwood / willow 

722 Oregon ash 

 

800 Maple / beech / birch group 

801 Sugar maple / beech / yellow birch 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix D 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 309

Code Forest type / type group 

802 Black cherry 

805 Hard maple / basswood 

809 Red maple / upland 

 

900 Aspen / birch group 

901 Aspen 

902 Paper birch 

903 Gray birch 

904 Balsam poplar 

905 Pin cherry 

 

910 Alder / maple group 

911 Red alder 

912 Bigleaf maple 

 

920 Western oak group 

921 Gray pine 

922 California black oak 

923 Oregon white oak 

924 Blue oak 

931 Coast live oak 

933 Canyon live oak 

934 Interior live oak 

935 California white oak (valley oak) 

 ` 

940 Tanoak / laurel group 

941 Tanoak 

942 California laurel 

943 Giant chinkapin 

 

960 Other hardwoods group 

961 Pacific madrone 

962 Other hardwoods 

 

970 Woodland hardwoods group 

971 Deciduous oak woodland 

972 Evergreen oak woodland 

973 Mesquite woodland 

974 Cercocarpus (mountain brush) woodland 

975 Intermountain maple woodland 

976 Miscellaneous woodland hardwoods 

 

980 Tropical hardwoods group 

982 Mangrove 

983 Palms 

989 Other tropical hardwoods 

 

990 Exotic hardwoods group 

991 Paulownia 

992 Melaleuca 

993 Eucalyptus 

995 Other exotic hardwoods 

 

999 Nonstocked 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix E 

310 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Appendix E. Administrative National Forest Codes and Names 

Region Code National Forest/Grassland/Area 

Region 1 102 Beaverhead 

102 Beaverhead-Deerlodge [now combined] 

 103 Bitterroot 

 104 Idaho Panhandle 

 105 Clearwater 

 108 Custer 

 109 Deerlodge 

 110 Flathead 

 111 Gallatin 

 112 Helena 

 114 Kootenai 

115 Lewis and Clark 

 116 Lolo 

 117 Nez Perce 

120 Cedar River NGL (National Grassland) 

121 Little Missouri NGL 

 122 Sheyenne NGL 

124 Grand River NGL 

199 Other NFS Areas 

 

Region 2 202 Bighorn 

 203 Black Hills 

 204 Grand Mesa-Uncompahgre-Gunnison 

 206 Medicine Bow 

206 Medicine Bow-Routt [now combined] 

 207 Nebraska 

 209 Rio Grande 

 210 Arapaho-Roosevelt 

 211 Routt 

212 Pike and San Isabel 

 213 San Juan 

 214 Shoshone 

 215 White River 

216 Samuel R Mckelvie 

 217 Cimarron NGL 

 218 Commanche NGL 

 219 Pawnee NGL 

 220 Oglala NGL 

221 Buffalo Gap NGL 

222 Fort Pierre NGL 

223 Thunder Basin NGL 

299 Other NFS Areas 

 

Region 3 301 Apache-Sitgreaves 

 302 Carson 

 303 Cibola 

 304 Coconino 

 305 Coronado 

 306 Gila 

 307 Kaibab 

 308 Lincoln 

 309 Prescott 

 310 Santa Fe 

 312 Tonto 

399 Other NFS Areas 

 

Region 4 401 Ashley 

 402 Boise 

 403 Bridger-Teton 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix E 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 311

Region Code National Forest/Grassland/Area 

 405 Caribou 

 406 Challis 

 407 Dixie 

 408 Fishlake 

 409 Humboldt 

 410 Manti-La Sal 

 412 Payette 

 413 Salmon 

 413 Salmon-Challis [now combined] 

 414 Sawtooth 

 415 Targhee 

 415 Caribou-Targhee [now combined] 

 417 Toiyabe 

 417 Humboldt-Toiyabe [now combined] 

 418 Uinta 

 419 Wasatch-Cache 

 420 Desert Range Experiment Station 

 499 Other NFS Areas 

 

Region 5 501 Angeles 

 502 Cleveland 

 503 Eldorado 

 504 Inyo 

 505 Klamath 

 506 Lassen 

 507 Los Padres 

 508 Mendocino 

 509 Modoc 

 510 Six Rivers 

 511 Plumas 

 512 San Bernardino 

 513 Sequoia 

 514 Shasta-Trinity 

 515 Sierra 

 516 Stanislaus 

 517 Tahoe 

 519 Lake Tahoe Basin 

 599 Other NFS Areas 

 

Region 6 601 Deschutes 

 602 Fremont 

 603 Gifford Pinchot 

 604 Malheur 

 605 Mt. Baker-Snoqualmie 

 606 Mt. Hood 

 607 Ochoco 

 608 Okanogan 

 609 Olympic 

 610 Rogue River 

 611 Siskiyou 

 612 Siuslaw 

 614 Umatilla 

 615 Umpqua 

 616 Wallowa-Whitman 

 617 Wenatchee 

 618 Willamette 

 620 Winema 

 621 Colville 

 622 Columbia River Gorge NSA 

 650 Crooked River National Grassland 

 699 Other NFS Areas 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix E 

312 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Region Code National Forest/Grassland/Area 

Region 8 801 NFS in Alabama 

 802 Daniel Boone 

 803 Chattahoochee-Oconee 

 804 Cherokee 

805 NFS in Florida 

 806 Kisatchie 

807 NFS in Mississippi 

 808 George Washington 

 809 Ouachita 

810 Ozark and St. Francis 

811 NFS in North Carolina 

 812 Francis Marion-Sumter 

813 NFS in Texas 

 814 Jefferson 

 816 El Yunque 

899 Other NFS areas 

 

Region 9 902 Chequamagon 

 903 Chippewa 

 904 Huron-Manistee 

 905 Mark Twain 

 906 Nicolet 

 907 Ottawa 

 908 Shawnee 

 909 Superior 

 910 Hiawatha 

 912 Hoosier 

915 Midewin Tallgrass Prairie 

 918 Wayne 

 919 Allegheny 

 920 Green Mountain 

 921 Monongahela 

 922 White Mountain 

999 Other NFS areas 

 

Region 10 1004 Chugach 

 1005 Tongass 

1099 Other NFS Areas 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix F 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 313

Appendix F. Tree Species Codes, Names, and Occurrences 

Major groups (MAJGRP) are (1) pines, (2) other softwoods, (3) soft hardwoods, and (4) hard hardwoods. The 48 

species groups (SPGRPCD) can be found in appendix G. The FIA work units listed are NC – (former) North Central, 

NE – (former) Northeastern, PNW – Pacific Northwest, RM – Rocky Mountain, and SO – Southern. 

 Occurrence by FIA work unit 

SPCD COMMON NAME SCIENTIFIC NAME SPGRPCD MAJGRP NC NE PNW RM SO 

0010 fir spp. Abies spp. 6 2 X X X 

0011 Pacific silver fir Abies amabilis 12 2 X 

0012 balsam fir Abies balsamea 6 2 X X X 

0014 Santa Lucia fir or 

bristlecone fir 

Abies bracteata 12 2 X 

0015 white fir Abies concolor 12 2 X X X 

0016 Fraser fir Abies fraseri 9 2 X X X 

0017 grand fir Abies grandis 12 2 X X 

0018 corkbark fir Abies lasiocarpa var. arizonica 12 2 X 

0019 subalpine fir Abies lasiocarpa 12 2 X X 

0020 California red fir Abies magnifica 12 2 X X 

0021 Shasta red fir Abies shastensis 12 2 X X 

0022 noble fir Abies procera 12 2 X X 

0040 white-cedar spp. Chamaecyparis spp. 9 E, 24 W 2 X X 

0041 Port-Orford-cedar Chamaecyparis lawsoniana 24 2 X 

0042 Alaska-yellow-cedar Chamaecyparis nootkatensis 24 2 X 

0043 Atlantic white-cedar Chamaecyparis thyoides 9 2 X X 

0050 cypress Cupressus spp. 24 2 X 

0051 Arizona cypress Cupressus arizonica 24 2 X X X 

0052 Baker or Modoc cypress Cupressus bakeri 24 2 X 

0053 Tecate cypress Cupressus forbesii 24 2 X 

0054 Monterey cypress Cupressus macrocarpa 24 2 X 

0055 Sargent’s cypress Cupressus sargentii 24 2 X 

0056 MacNab’s cypress Cupressus macnabiana 9 E, 24 W 2 X 

0057 redcedar / juniper spp. Juniperus spp. 9 E, 23 W 2 X X X 

0058 Pinchot juniper Juniperus pinchotii 23 2 X 

0059 redberry juniper Juniperus coahuilensis 23 2 X X 

0060 Drooping juniper Juniperus flaccida 23 2 X 

0061 Ashe juniper Juniperus ashei 23 2 X X 

0062 California juniper Juniperus californica 23 2 X X 

0063 alligator juniper Juniperus deppeana 23 2 X X 

0064 western juniper Juniperus occidentalis 24 2 X X 

0065 Utah juniper Juniperus osteosperma 23 2 X X 

0066 Rocky Mountain juniper Juniperus scopulorum 9 E, 23 W 2 X X X X 

0067 southern redcedar Juniperus virginiana var. 

silicicola 

9 2 X 

0068 eastern redcedar Juniperus virginiana 9 E, 24 W 2 X X X X 

0069 oneseed juniper Juniperus monosperma 23 2 X X 

0070 larch spp. Larix spp. 9 2 X X 

0071 tamarack (native) Larix laricina 9 E, 24 W 2 X X X 

0072 subalpine larch Larix lyallii 24 2 X X 

0073 western larch Larix occidentalis 19 2 X X 

0081 incense-cedar Calocedrus decurrens 20 2 X X 

0090 spruce spp. Picea spp. 6 2 X X X 

0091 Norway spruce Picea abies 9 2 X X X 

0092 Brewer spruce Picea breweriana 18 2 X 

0093 Engelmann spruce Picea engelmannii 9 E, 18 W 2 X X X 

0094 white spruce Picea glauca 6 E, 18 W 2 X X X X X 

0095 black spruce Picea mariana 6 E, 18 W 2 X X X X 

0096 blue spruce Picea pungens 9 E, 18 W 2 X X X X 

0097 red spruce Picea rubens 6 2 X X 

0098 Sitka spruce Picea sitchensis 17 2 X 

0100 pine spp. Pinus spp. 9 E, 24 W 1 X X X 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix F 

314 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 Occurrence by FIA work unit 

SPCD COMMON NAME SCIENTIFIC NAME SPGRPCD MAJGRP NC NE PNW RM SO 

0101 whitebark pine Pinus albicaulis 24 1 X X 

0102 Rocky Mountain 

bristlecone pine 

Pinus aristata 24 1 X 

0103 knobcone pine Pinus attenuata 24 1 X 

0104 foxtail pine Pinus balfouriana 24 1 X X 

0105 jack pine Pinus banksiana 5 1 X X 

0106 common or two-needle 

pinyon 

Pinus edulis 23 1 X X X 

0107 sand pine Pinus clausa 3 1 X 

0108 lodgepole pine Pinus contorta 21 1 X X X 

0109 Coulter pine Pinus coulteri 24 1 X 

0110 shortleaf pine Pinus echinata 2 1 X X X 

0111 slash pine Pinus elliottii 1 1 X 

0112 Apache pine Pinus engelmannii 24 1 X 

0113 limber pine Pinus flexilis 24 1 X X X X 

0114 southwestern white pine Pinus strobiformis 24 1 X 

0115 spruce pine Pinus glabra 3 1 X 

0116 Jeffrey pine Pinus jeffreyi 11 1 X X 

0117 sugar pine Pinus lambertiana 14 1 X X 

0118 Chihuahua pine Pinus leiophylla 24 1 X 

0119 western white pine Pinus monticola 15 1 X X 

0120 bishop pine Pinus muricata 24 1 X 

0121 longleaf pine Pinus palustris 1 1 X 

0122 ponderosa pine Pinus ponderosa 9 E, 11 W 1 X X X X 

0123 Table mountain pine Pinus pungens 3 1 X X 

0124 Monterey pine Pinus radiata 24 1 X 

0125 red pine Pinus resinosa 4 1 X X X 

0126 pitch pine Pinus rigida 3 1 X X 

0127 gray pine or California 

foothill pine 

Pinus sabiniana 24 1 X 

0128 pond pine Pinus serotina 3 1 X X 

0129 eastern white pine Pinus strobus 4 1 X X X 

0130 Scotch pine Pinus sylvestris 3 E, 24 W 1 X X X X X 

0131 loblolly pine Pinus taeda 2 1 X X X 

0132 Virginia pine Pinus virginiana 3 1 X X X 

0133 singleleaf pinyon Pinus monophylla 23 1 X X 

0134 border pinyon Pinus discolor 23 1 X 

0135 Arizona pine Pinus arizonica 11 1 X 

0136 Austrian pine Pinus nigra 9 E, 24 W 1 X X X X 

0137 Washoe pine Pinus washoensis 24 1 X X 

0138 four-leaf pine or Parry 

pinyon pine 

Pinus quadrifolia 24 1 X 

0139 Torrey pine Pinus torreyana 24 1 X 

0140 Mexican pinyon pine Pinus cembroides 23 1 X X 

0141 papershell pinyon pine Pinus remota 23 1 X 

0142 Great Basin bristlecone 

pine 

Pinus longaeva 24 1 X X 

0143 Arizona pinyon pine Pinus monophylla var. fallax 23 1 X 

0144 Honduras pine Pinus elliottii var. elliottii 9 E, 24 W 1 X 

0200 Douglas-fir spp. Pseudotsuga spp. 9 E, 10 W 2 X X 

0201 bigcone Douglas-fir Pseudotsuga macrocarpa 10 2 X 

0202 Douglas-fir Pseudotsuga menziesii 9 E, 10 W 2 X X X X 

0211 redwood Sequoia sempervirens 16 2 X 

0212 giant sequoia Sequoiadendron giganteum 24 2 X 

0220 baldcypress spp. Taxodium spp. 9 E, 24 W 2 X X X 

0221 baldcypress Taxodium distichum 8 2 X X X 

0222 pondcypress Taxodium ascendens 8 2 X 

0223 Montezuma baldcypress Taxodium mucronatum 8 2 X 

0230 yew spp. Taxus spp. 9 E, 24 W 2 X X 

0231 Pacific yew Taxus brevifolia 24 2 X X 

0232 Florida yew Taxus floridana 9 E, 24 W 2 X 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix F 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 315

 Occurrence by FIA work unit 

SPCD COMMON NAME SCIENTIFIC NAME SPGRPCD MAJGRP NC NE PNW RM SO 

0240 Thuja spp. Thuja spp. 9 E, 24 W 2 X X 

0241 northern white-cedar Thuja occidentalis 9 2 X X X 

0242 western redcedar Thuja plicata 22 2 X X 

0250 Torreya (nutmeg) spp. Torreya spp. 9 E, 24 W 2 X 

0251 California torreya 

(nutmeg) 

Torreya californica 24 2 X 

0252 Florida torreya (nutmeg) Torreya taxifolia 9 2 X 

0260 hemlock spp. Tsuga spp. 7 2 X X 

0261 eastern hemlock Tsuga canadensis 7 2 X X X 

0262 Carolina hemlock Tsuga caroliniana 7 2 X 

0263 western hemlock Tsuga heterophylla 13 2 X X 

0264 mountain hemlock Tsuga mertensiana 24 2 X X 

0299 Unknown dead conifer Tree evergreen 9 E, 24 W 2 X X X X X 

0300 acacia spp. Acacia spp. 41 E, 48 W 3 X 

0303 sweet acacia Acacia farnesiana 43 E, 48 W 3 X X 

0304 catclaw acacia Acacia greggii 43 E, 48 W 3 X X X 

0310 maple spp. Acer spp. 31 4 X X X 

0311 Florida maple Acer barbatum 31 4 X 

0312 bigleaf maple Acer macrophyllum 47 3 X X 

0313 boxelder Acer negundo 41 E, 47 W 3 X X X X X 

0314 black maple Acer nigrum 31 4 X X X 

0315 striped maple Acer pensylvanicum 43 3 X X X 

0316 red maple Acer rubrum 32 3 X X X 

0317 silver maple Acer saccharinum 32 3 X X X 

0318 sugar maple Acer saccharum 31 4 X X X 

0319 mountain maple Acer spicatum 43 4 X X X 

0320 Norway maple Acer platanoides 31 E, 47 W 4 X X X 

0321 Rocky Mountain maple Acer glabrum 43 E, 48 W 4 X X 

0322 bigtooth maple Acer grandidentatum 48 4 X X 

0323 chalk maple Acer leucoderme 31 4 X 

0330 buckeye, horsechestnut 

spp. 

Aesculus spp. 41 E, 47 W 3 X X X 

0331 Ohio buckeye Aesculus glabra 41 E, 47 W 3 X X X 

0332 yellow buckeye Aesculus flava 43 3 X X X 

0333 California buckeye Aesculus californica 41 E, 47 W 3 X 

0334 Texas buckeye Aesculus glabra var. arguta 41 3 X X 

0336 red buckeye Aesculus pavia 43 E, 47 W 3 X X X 

0337 painted buckeye Aesculus sylvatica 41 E, 47 W 3 X X 

0341 ailanthus Ailanthus altissima 43 E, 47 W 4 X X X X 

0345 mimosa, silktree Albizia julibrissin 43 3 X X 

0350 alder spp. Alnus spp. 41 E, 47 W 3 X X 

0351 red alder Alnus rubra 45 3 X X X 

0352 white alder Alnus rhombifolia 47 3 X X 

0353 Arizona alder Alnus oblongifolia 43 E, 47 W 3 X 

0355 European alder Alnus glutinosa 41 E, 47 W 3 X X 

0356 serviceberry spp. Amelanchier spp. 43 E, 48 W 4 X X X 

0357 common serviceberry Amelanchier arborea 43 E, 48 W 4 X 

0358 roundleaf serviceberry Amelanchier sanguinea 43 E, 48 W 4 X 

0360 Madrone spp. Arbutus spp. 43 E, 47 W 4 X 

0361 Pacific madrone Arbutus menziesii 47 4 X X 

0362 Arizona madrone Arbutus arizonica 43 E, 47 W 4 X 

0363 Texas madrone Arbutus xalapensis 48 4 X 

0367 pawpaw Asimina triloba 43 3 X X X 

0370 birch spp. Betula spp. 41 4 X X X 

0371 yellow birch Betula alleghaniensis 30 4 X X X 

0372 sweet birch Betula lenta 42 4 X X X 

0373 river birch Betula nigra 41 3 X X X 

0374 water birch Betula occidentalis 41 E, 47 W 3 X X X 

0375 paper birch Betula papyrifera 41 E, 47 W 3 X X X X 

0377 Virginia roundleaf birch Betula uber 41 E, 47 W 3 X 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix F 

316 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 Occurrence by FIA work unit 

SPCD COMMON NAME SCIENTIFIC NAME SPGRPCD MAJGRP NC NE PNW RM SO 

0378 northwestern paper birch Betula x utahensis 47 3 X 

0379 gray birch Betula populifolia 41 3 X X X 

0381 chittamwood,gum bumelia Sideroxylon lanuginosum ssp. 

lanuginosum 

43 4 X X 

0391 American hornbeam, 

musclewood 

Carpinus caroliniana 43 4 X X X 

0400 hickory spp. Carya spp. 29 4 X X X 

0401 water hickory Carya aquatica 29 4 X X 

0402 bitternut hickory Carya cordiformis 29 4 X X X 

0403 pignut hickory Carya glabra 29 4 X X X 

0404 pecan Carya illinoinensis 29 E, 47 W 4 X X X X 

0405 shellbark hickory Carya laciniosa 29 4 X X X 

0406 nutmeg hickory Carya myristiciformis 29 4 X 

0407 shagbark hickory Carya ovata 29 4 X X X 

0408 black hickory Carya texana 29 4 X X 

0409 mockernut hickory Carya alba 29 4 X X X 

0410 sand hickory Carya pallida 29 4 X X X 

0411 scrub hickory Carya floridana 29 E, 47 W 4 X 

0412 red hickory Carya ovalis 29 E, 47 W 4 X X X 

0413 southern shagbark hickory Carya carolinae-septentrionalis 29 E, 47 W 4 X 

0420 chestnut spp. Castanea spp. 43 E, 47 W 3 X X X 

0421 American chestnut Castanea dentata 43 3 X X X 

0422 Allegheny chinkapin Castanea pumila 43 3 X X X 

0423 Ozark chinkapin Castanea pumila var. ozarkensis 43 3 X X 

0424 Chinese chestnut Castanea mollissima 43 E, 47 W 3 X X X 

0431 giant chinkapin,golden 

chinkapin 

Chrysolepis chrysophylla var.

chrysophylla 

47 3 X 

0450 catalpa spp. Catalpa spp. 42 4 X X X 

0451 southern catalpa Catalpa bignonioides 43 4 X X 

0452 northern catalpa Catalpa speciosa 41 3 X X X 

0460 hackberry spp. Celtis 41 3 X X X 

0461 sugarberry Celtis laevigata 41 E, 47 W 3 X X X 

0462 hackberry Celtis occidentalis 41 E, 47 W 3 X X X 

0463 netleaf hackberry Celtis laevigata var. reticulata 41 3 X X 

0471 eastern redbud Cercis canadensis 43 3 X X X 

0475 curlleaf mountainmahogany 

Cercocarpus ledifolius 48 4 X X 

0481 yellowwood Cladrastis kentukea 43 4 X X X 

0490 dogwood spp. Cornus spp. 43 E, 47 W 4 X X X 

0491 flowering dogwood Cornus florida 42 4 X X X 

0492 Pacific dogwood Cornus nuttallii 47 4 X X 

0500 hawthorn spp. Crataegus spp. 43 E, 47 W 4 X X X 

0501 cockspur hawthorn Crataegus crus-galli 43 4 X X X 

0502 downy hawthorn Crataegus mollis 43 4 X X X 

0503 Brainerd’s hawthorn Crataegus brainerdii 43 E, 47 W 4 X X X 

0504 pear hawthorn Crataegus calpodendron 43 E, 47 W 4 X X X 

0505 fireberry hawthorn Crataegus chrysocarpa 43 E, 47 W 4 X X X 

0506 broadleaf hawthorn Crataegus dilatata 43 E, 47 W 4 X X X 

0507 fanleaf hawthorn Crataegus flabellata 43 E, 47 W 4 X X X 

0508 oneseed hawthorn Crataegus monogyna 43 E, 47 W 4 X X X 

0509 scarlet hawthorn Crataegus pedicellata 43 E, 47 W 4 X X X 

5091 Washington hawthorn Crataegus phaenopyrum 43 E, 47 W 4 X X X 

5092 fleshy hawthorn Crataegus succulenta 43 E, 47 W 4 X X X 

5093 dwarf hawthorn Crataegus uniflora 43 E, 47 W 4 X X X 

0510 eucalyptus spp. Eucalyptus spp. 42 E, 47 W 4 X X X 

0511 Tasmanian bluegum Eucalyptus globulus 43 E, 47 W 4 X 

0512 river redgum Eucalyptus camaldulensis 43 E, 47 W 4 X 

0513 grand eucalyptus Eucalyptus grandis 43 E, 47 W 4 X X 

0514 swampmahogany Eucalyptus robusta 43 E, 47 W 4 X 

0520 persimmon spp. Diospyros spp. 43 E, 47 W 4 X X X 

0521 common persimmon Diospyros virginiana 42 4 X X X 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix F 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 317

 Occurrence by FIA work unit 

SPCD COMMON NAME SCIENTIFIC NAME SPGRPCD MAJGRP NC NE PNW RM SO 

0522 Texas persimmon Diospyros texana 43 E, 47 W 4 X 

0523 Anacua knockaway Ehretia anacua 48 3 X 

0531 American beech Fagus grandifolia 33 4 X X X 

0540 ash spp. Fraxinus spp. 36 E, 47 W 3 X X X X 

0541 white ash Fraxinus americana 36 4 X X X 

0542 Oregon ash Fraxinus latifolia 47 4 X 

0543 black ash Fraxinus nigra 36 3 X X X 

0544 green ash Fraxinus pennsylvanica 36 E, 47 W 4 X X X X 

0545 pumpkin ash Fraxinus profunda 36 3 X X X 

0546 blue ash Fraxinus quadrangulata 36 4 X X X 

0547 velvet ash Fraxinus velutina 47 4 X X 

0548 Carolina ash Fraxinus caroliniana 36 4 X 

0549 Texas ash Fraxinus texensis 36 E, 47 W 3 X 

5491 Berlandier ash Fraxinus berlandieriana 36 3 X 

0550 honeylocust spp. Gleditsia spp. 42 E, 47 W 4 X X X 

0551 waterlocust Gleditsia aquatica 42 4 X X 

0552 honeylocust Gleditsia triacanthos 42 E, 47 W 4 X X X X 

0555 loblolly-bay Gordonia lasianthus 41 3 X 

0561 Ginkgo, maidenhair tree Ginkgo biloba 43 E, 47 W 3 X X X 

0571 Kentucky coffeetree Gymnocladus dioicus 42 4 X X X 

0580 silverbell spp. Halesia spp. 43 3 X X X 

0581 Carolina silverbell Halesia carolina 41 E, 47 W 3 X 

0582 two-wing silverbell Halesia diptera 41 E, 47 W 3 X 

0583 little silverbell Halesia parviflora 41 E, 47 W 3 X 

0591 American holly Ilex opaca 42 E, 47 W 4 X X X X 

0600 walnut spp. Juglans spp. 41 E, 47 W 4 X X X X X 

0601 butternut Juglans cinerea 41 3 X X X 

0602 black walnut Juglans nigra 40 E, 47 W 4 X X X X X 

0603 northern California black 

walnut 

Juglans hindsii 47 4 X 

0604 southern California black 

walnut 

Juglans californica 47 4 X 

0605 Texas walnut Juglans microcarpa 41 E, 47 W 4 X X 

0606 Arizona walnut Juglans major 43 E, 47 W 4 X 

0611 sweetgum Liquidambar styraciflua 34 E, 47 W 3 X X X 

0621 yellow-poplar Liriodendron tulipifera 39 3 X X X 

0631 tanoak Lithocarpus densiflorus 47 4 X 

0641 Osage-orange Maclura pomifera 43 4 X X X 

0650 magnolia spp. Magnolia spp. 41 3 X X X 

0651 cucumbertree Magnolia acuminata 41 3 X X X 

0652 southern magnolia Magnolia grandiflora 41 3 X X 

0653 sweetbay Magnolia virginiana 43 3 X X 

0654 bigleaf magnolia Magnolia macrophylla 43 4 X X 

0655 mountain or Fraser 

magnolia 

Magnolia fraseri 41 3 X X 

0657 pyramid magnolia Magnolia pyramidata 41 E, 47 W 3 X 

0658 umbrella magnolia Magnolia tripetala 41 E, 47 W 3 X X X 

0660 apple spp. Malus spp. 43 E, 47 W 4 X X X X X 

0661 Oregon crab apple Malus fusca 47 4 X 

0662 southern crabapple Malus angustifolia 43 E, 47 W 4 X X X 

0663 sweet crabapple Malus coronaria 43 E, 47 W 4 X X X 

0664 prairie crabapple Malus ioensis 43 E, 47 W 4 X 

0680 mulberry spp. Morus spp. 42 4 X X X X 

0681 white mulberry Morus alba 42 4 X X X 

0682 red mulberry Morus rubra 42 4 X X X 

0683 Texas mulberry Morus microphylla 42 E, 47 W 4 X 

0684 black mulberry Morus nigra 43 E, 47 W 4 X X 

0690 tupelo spp. Nyssa spp. 35 E, 47 W 3 X X X 

0691 water tupelo Nyssa aquatica 35 3 X X 

0692 Ogeechee tupelo Nyssa ogeche 43 4 X 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix F 

318 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 Occurrence by FIA work unit 

SPCD COMMON NAME SCIENTIFIC NAME SPGRPCD MAJGRP NC NE PNW RM SO 

0693 blackgum Nyssa sylvatica 35 3 X X X 

0694 swamp tupelo Nyssa biflora 35 3 X X X 

0701 eastern hophornbeam Ostrya virginiana 43 4 X X X 

0711 sourwood Oxydendrum arboreum 43 4 X X X 

0712 paulownia, empress-tree Paulownia tomentosa 41 3 X X X 

0720 bay spp. Persea spp. 43 E, 47 W 3 X X 

0721 redbay Persea borbonia 41 3 X 

7211 avocado Persea americana 43 E, 47 W 3 X 

0722 water-elm, planertree Planera aquatica 43 3 X X 

0729 Sycamore spp. Platanus spp. 41 E, 47 W 3 X X X 

0730 California sycamore Platanus racemosa 47 3 X 

0731 American sycamore Platanus occidentalis 41 E, 47 W 3 X X X X X 

0732 Arizona sycamore Platanus wrightii 41 E, 47 W 3 X 

0740 cottonwood and poplar 

spp. 

Populus spp. 37 E, 44 W 3 X X X 

0741 balsam poplar Populus balsamifera 37 E, 44 W 3 X X X X 

0742 eastern cottonwood Populus deltoides 37 E, 44 W 3 X X X X 

0743 bigtooth aspen Populus grandidentata 37 3 X X X 

0744 swamp cottonwood Populus heterophylla 37 3 X X X 

0745 plains cottonwood Populus deltoides ssp.

monilifera 

37 E, 44 W 3 X X 

0746 quaking aspen Populus tremuloides 37 E, 44 W 3 X X X X X 

0747 black cottonwood Populus balsamifera ssp. 

trichocarpa 

37 E, 44 W 4 X X X 

0748 Fremont cottonwood Populus fremontii 37 E, 44 W 4 X X X 

0749 narrowleaf cottonwood Populus angustifolia 37 E, 44 W 3 X X X 

0752 silver poplar Populus alba 37 3 X X 

0753 Lombardy poplar Populus nigra 37 E, 44 W 3 X X X 

0755 mesquite spp. Prosopis spp. 48 4 X 

0756 honey mesquite Prosopis glandulosa 48 4 X X X 

0757 velvet mesquite Prosopis velutina 48 4 X X X 

0758 screwbean mesquite Prosopis pubescens 48 4 X X X 

0760 cherry and plum spp. Prunus spp. 43 E, 47 W 4 X X X X 

0761 pin cherry Prunus pensylvanica 43 3 X X X 

0762 black cherry Prunus serotina 41 3 X X X 

0763 chokecherry Prunus virginiana 43 E, 47 W 4 X X X X 

0764 peach Prunus persica 43 E, 47 W 3 X X X 

0765 Canada plum Prunus nigra 43 4 X 

0766 American plum Prunus americana 43 4 X X X 

0768 bitter cherry Prunus emarginata 47 4 X 

0769 Allegheny plum Prunus alleghaniensis 43 E, 47 W 3 X X X 

0770 Chickasaw plum Prunus angustifolia 43 E, 47 W 3 X X X 

0771 sweet cherry, domesticated Prunus avium 43 E, 47 W 3 X X X 

0772 sour cherry, domesticated Prunus cerasus 43 E, 47 W 3 X X X 

0773 European plum, 

domesticated 

Prunus domestica 43 E, 47 W 3 X X X 

0774 Mahaleb cherry, 

domesticated 

Prunus mahaleb 43 E, 47 W 3 X X X 

0800 oak spp Quercus spp. 42 E, 48 W 4 X X X X 

0801 California live oak Quercus agrifolia 46 4 X 

0802 white oak Quercus alba 25 4 X X X 

0803 Arizona white oak Quercus arizonica 48 4 X X 

0804 swamp white oak Quercus bicolor 25 4 X X X 

0805 canyon live oak Quercus chrysolepis 46 4 X 

0806 scarlet oak Quercus coccinea 28 4 X X X 

0807 blue oak Quercus douglasii 46 4 X 

0808 Durand oak Quercus sinuata var. sinuata 25 4 X 

0809 northern pin oak Quercus ellipsoidalis 28 4 X X X 

0810 Emory oak Quercus emoryi 48 4 X X 

0811 Engelmann oak Quercus engelmannii 46 4 X 

0812 southern red oak Quercus falcata 28 4 X X X 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix F 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 319

 Occurrence by FIA work unit 

SPCD COMMON NAME SCIENTIFIC NAME SPGRPCD MAJGRP NC NE PNW RM SO 

0813 cherrybark oak Quercus pagoda 26 4 X X X 

0814 Gambel oak Quercus gambelii 48 4 X X 

0815 Oregon white oak Quercus garryana 46 4 X 

0816 scrub oak Quercus ilicifolia 43 4 X X 

0817 shingle oak Quercus imbricaria 28 4 X X X 

0818 California black oak Quercus kelloggii 46 4 X 

0819 turkey oak Quercus laevis 43 4 X 

0820 laurel oak Quercus laurifolia 28 4 X X 

0821 California white oak Quercus lobata 46 4 X 

0822 overcup oak Quercus lyrata 27 4 X X X 

0823 bur oak Quercus macrocarpa 25 E, 47 W 4 X X X X 

0824 blackjack oak Quercus marilandica 28 4 X X X 

0825 swamp chestnut oak Quercus michauxii 25 4 X X X 

0826 chinkapin oak Quercus muehlenbergii 25 E, 47 W 4 X X X X 

0827 water oak Quercus nigra 28 4 X X X 

0828 Texas red oak Quercus texana 28 4 X X 

0829 Mexican blue oak Quercus oblongifolia 48 4 X 

0830 pin oak Quercus palustris 28 4 X X X 

0831 willow oak Quercus phellos 28 4 X X X 

0832 chestnut oak Quercus prinus 27 4 X X X 

0833 northern red oak Quercus rubra 26 4 X X X 

0834 Shumard oak Quercus shumardii 26 4 X X X 

0835 post oak Quercus stellata 27 4 X X X 

0836 Delta post oak Quercus similis 27 4 X 

0837 black oak Quercus velutina 28 4 X X X 

0838 live oak Quercus virginiana 27 4 X 

0839 interior live oak Quercus wislizeni 46 4 X 

0840 dwarf post oak Quercus margarettiae 27 4 X X 

0841 dwarf live oak Quercus minima 27 4 X 

0842 bluejack oak Quercus incana 43 4 X 

0843 silverleaf oak Quercus hypoleucoides 48 4 X X 

0844 Oglethorpe oak Quercus oglethorpensis 27 4 X 

0845 dwarf chinkapin oak Quercus prinoides 43 4 X X 

0846 gray oak Quercus grisea 48 4 X X 

0847 netleaf oak Quercus rugosa 43 E, 48 W 4 X 

0851 Chisos oak Quercus gracilliformis 26 4 X 

8511 Graves oak Quercus gravesii 26 4 X 

8512 Mexican white oak Quercus polymorpha 26 4 X 

8513 Buckley oak Quercus buckleyi 26 4 X 

8514 Lacey oak Quercus laceyi 26 4 X 

0852 sea torchwood Amyris elemifera 43 E, 47 W 3 X 

0853 pond-apple Annona glabra 43 E, 47 W 3 X 

0854 gumbo limbo Bursera simaruba 43 E, 47 W 3 X 

0855 sheoak spp. Casuarina spp. 43 E, 47 W 3 X 

0856 gray sheoak Casuarina glauca 43 E, 47 W 3 X 

0857 belah Casuarina lepidophloia 43 E, 47 W 3 X 

0858 camphortree Cinnamomum camphora 43 E, 47 W 3 X 

0859 Florida fiddlewood Citharexylum fruticosum 43 E, 47 W 3 X 

0860 citrus spp. Citrus spp. 43 E, 47 W 3 X 

0863 tietongue, pigeon-plum Coccoloba diversifolia 43 E, 47 W 3 X 

0864 soldierwood Colubrina elliptica 43 E, 47 W 3 X 

0865 longleaf geigertree Cordia sebestena 43 E, 47 W 3 X 

8651 Anacahuita Texas Olive Cordia boissieri 27 4 X 

0866 carrotwood Cupaniopsis anacardioides 43 E, 47 W 3 X 

0867 bluewood Condalia hookeri 48 4 X 

0868 blackbead ebony Ebenopsis ebano 42 E, 47 W 4 X 

0869 great leadtree Leucaena pulverulenta 43 3 X 

0870 Texas sophora Sophora affinis 42 E 4 X 

0873 red stopper Eugenia rhombea 43 E, 47 W 3 X 

0874 butterbough, inkwood Exothea paniculata 43 E, 47 W 3 X 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix F 

320 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

 Occurrence by FIA work unit 

SPCD COMMON NAME SCIENTIFIC NAME SPGRPCD MAJGRP NC NE PNW RM SO 

0876 Florida strangler fig Ficus aurea 43 E, 47 W 3 X 

0877 wild banyantree, shortleaf 

fig 

Ficus citrifolia 43 E, 47 W 3 X 

0882 beeftree, longleaf blolly Guapira discolor 43 E, 47 W 3 X 

0883 manchineel Hippomane mancinella 43 E, 47 W 3 X 

0884 false tamarind Lysiloma latisiliquum 43 E, 47 W 3 X 

0885 mango Mangifera indica 43 E, 47 W 3 X 

0886 Florida poisontree Metopium toxiferum 43 E, 47 W 3 X 

0887 fishpoison tree Piscidia piscipula 43 E, 47 W 3 X 

0888 octopus tree, schefflera Schefflera actinophylla 43 E, 47 W 3 X 

0890 false mastic Sideroxylon foetidissimum 43 E, 47 W 3 X 

0891 white bully, willow bustic Sideroxylon salicifolium 43 E, 47 W 3 X 

0895 paradisetree Simarouba glauca 43 E, 47 W 3 X 

0896 Java plum Syzygium cumini 43 E, 47 W 3 X 

0897 tamarind Tamarindus indica 43 E, 47 W 3 X 

0901 black locust Robinia pseudoacacia 42 E, 47 W 4 X X X X 

0902 New Mexico locust Robinia neomexicana 48 4 X X 

0906 Everglades palm, paurotispalm 

Acoelorraphe wrightii 43 E, 47 W 3 X 

0907 Florida silver palm Coccothrinax argentata 43 E, 47 W 3 X 

0908 coconut palm Cocos nucifera 43 E, 47 W 3 X 

0909 royal palm spp. Roystonea spp. 43 E, 47 W 3 X 

0911 Mexican palmetto Sabal Mexicana 41 E 3 X 

0912 cabbage palmetto Sabal palmetto 43 E, 47 W 3 X 

0913 key thatch palm Thrinax morrisii 43 E, 47 W 3 X 

0914 Florida thatch palm Thrinax radiata 43 E, 47 W 3 X 

0915 other palms Family Arecaceae not listed 

above 

43 E, 47 W 3 X 

0919 western soapberry Sapindus saponaria var. 

drummondii 

43 4 X X 

0920 willow spp. Salix spp. 43 E, 47 W 3 X X X X 

0921 peachleaf willow Salix amygdaloides 43 3 X X 

0922 black willow Salix nigra 41 E, 47 W 3 X X X X 

0923 Bebb willow Salix bebbiana 43 E, 47 W 3 X 

0924 Bonpland willow Salix bonplandiana 41 E, 47 W 3 X 

0925 coastal plain willow Salix caroliniana 43 E, 47 W 3 X X X 

0926 balsam willow Salix pyrifolia 43 E, 47 W 3 X X 

0927 white willow Salix alba 41 3 X X X 

0928 Scouler’s willow Salix scouleriana 41 E, 47 W 3 X X 

0929 weeping willow Salix sepulcralis 41 E, 47 W 3 X X X 

0931 sassafras Sassafras albidum 41 3 X X X 

0934 mountain-ash spp. Sorbus spp. 43 E, 47 W 4 X X X 

0935 American mountain-ash Sorbus americana 43 4 X X X 

0936 European mountain-ash Sorbus aucuparia 43 4 X X 

0937 northern mountain-ash Sorbus decora 43 E, 47 W 4 X X 

0940 West Indian mahogany Swietenia mahagoni 43 E, 47 W 4 X 

0950 basswood spp. Tilia spp. 38 3 X X X 

0951 American basswood Tilia americana 38 3 X X X 

0952 white basswood Tilia americana var. 

heterophylla 

38 3 X X X 

0953 Carolina basswood Tilia americana var. caroliniana 38 3 X X 

0970 elm spp. Ulmus 41 3 X X X 

0971 winged elm Ulmus alata 41 4 X X X 

0972 American elm Ulmus americana 41 E, 47 W 3 X X X X 

0973 cedar elm Ulmus crassifolia 41 3 X X 

0974 Siberian elm Ulmus pumila 41 E, 47 W 3 X X X 

0975 slippery elm Ulmus rubra 41 3 X X X 

0976 September elm Ulmus serotina 41 3 X X 

0977 rock elm Ulmus thomasii 42 4 X X X 

0981 California-laurel Umbellularia californica 47 4 X 

0982 Joshua tree Yucca brevifolia 43 E, 47 W 3 X 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix F 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 321

 Occurrence by FIA work unit 

SPCD COMMON NAME SCIENTIFIC NAME SPGRPCD MAJGRP NC NE PNW RM SO 

0986 black-mangrove Avicennia germinans 43 E, 47 W 4 X 

0987 button mangrove Conocarpus erectus 43 E, 47 W 4 

0988 white-mangrove Laguncularia racemosa 43 E, 47 W 4 X 

0989 American mangrove Rhizophora mangle 43 4 X 

0990 desert ironwood Olneya tesota 43 E, 48 W 4 X 

0991 saltcedar Tamarix spp. 43 E, 47 W 3 X X X 

0992 melaleuca Melaleuca quinquenervia 41 E, 47 W 3 X 

0993 chinaberry Melia azedarach 43 4 X X X 

0994 Chinese tallowtree Triadica sebifera 43 4 X 

0995 tungoil tree Vernicia fordii 43 4 X 

0996 smoketree Cotinus obovatus 43 4 X X 

0997 Russian-olive Elaeagnus angustifolia 43 E, 47 W 3 X X 

0998 unknown dead hardwood Tree broadleaf 43 E, 47 W 3 X X X X 

0999 other or unknown live tree Tree unknown 43 E, 47 W 3 X X X 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix G 

322 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Appendix G. Tree Species Group Codes

Species group name Code

Softwood species groups 

 Eastern softwood species groups 

 Longleaf and slash pines 1 

 Loblolly and shortleaf pines 2 

 Other yellow pines 3 

 Eastern white and red pines 4 

 Jack pine 5 

 Spruce and balsam fir 6 

 Eastern hemlock 7 

 Cypress 8 

 Other eastern softwoods 9 

 Western softwood species groups 

 Douglas-fir 10 

 Ponderosa and Jeffrey pines 11 

 True fir 12 

 Western hemlock 13 

 Sugar pine 14 

 Western white pine 15 

 Redwood 16 

 Sitka spruce 17 

 Engelmann and other spruces 18 

 Western larch 19 

 Incense-cedar 20 

 Lodgepole pine 21 

 Western redcedar 22 

 Western woodland softwoods 23 

 Other western softwoods 24 

 

Hardwood species groups 

 Eastern hardwood species groups 

 Select white oaks 25 

 Select red oaks 26 

 Other white oaks 27 

 Other red oaks 28 

 Hickory 29 

 Yellow birch 30 

 Hard maple 31 

 Soft maple 32 

 Beech 33 

 Sweetgum 34 

 Tupelo and blackgum 35 

 Ash 36 

 Cottonwood and aspen 37 

 Basswood 38 

 Yellow-poplar 39 

 Black walnut 40 

 Other eastern soft hardwoods 41 

 Other eastern hard hardwoods 42 

 Eastern noncommercial hardwoods 43 

 Western hardwood species groups 

 Cottonwood and aspen 44 

 Red alder 45 

 Oak 46 

 Other western hardwoods 47 

 Western woodland hardwoods 48 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix H 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 323

Appendix H. Damage Agent codes for PNW 

Damage Agent is a 2-digit code with values 01 to 91. For Agent and Severity 1, 2 and 3: the agent and severity codes 

indicate the type of agents that were present on a tree and describe their severity. Several damaging agents are 

automatically of highest importance and should be coded before any other agents; these agents are grouped as Class I 

Agents. Class I insects, diseases, or physical injuries can seriously affect vegetation. Failure to account for these agents 

can result in large differences in predicted outcomes for tree growth, survival, vegetative composition and structure. 

Class II agents can be important in local situations; recording their incidence and severity provides valuable information 

for those situations. Class II agents are recorded when present but only after all Class I agents. 

Agents and their severity ratings are grouped by broad category. Each category has a general agent and specific agents 

listed. The general codes should be used if there is any question as to the identity of the specific damaging agent. 

Class I Agents 

Agents Severity 

 Code Agent Code Severity 

Bark beetles: 

 01 General /other bark beetle 1 Unsuccessful current attack 

 02 Mountain pine beetle 2 Successful current attack 

 03 Douglas-fir beetle 3 Last year’s successful attack 

 04 Spruce beetle 4 Older dead 

 05 Western pine beetle 5 Top kill 

 06 Pine engraver beetle 

 07 Fir engraver beetle 

 08 Silver fir beetle 

 09 Red turpentine beetle 

 26 Jeffrey pine beetle 

 Code Agent Code Severity 

Defoliators: 0 

1 

2 

3 

No detectable defoliation 

Up to 33% of foliage (old and new 

missing/affected) 

34 to 66% of foliage missing/affected 

67 to 100% of foliage missing/affected 

 10 General/other 

 11 Western blackheaded 

budworm 

 12 Pine butterfly 

13 Douglas-fir tussock moth 

 14 Larch casebearer 

15 Western spruce or Modoc 

budworm 

16 Western hemlock looper 

 17 Sawflies 

 18 Needles and sheath miners 

 19 Gypsy moth 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix H 

324 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Class I Agents 

Agents Severity 

 Code Agent Code Severity 

Root 

diseases: 

 

 60 General/other 1 

2 

3 

Tree is a live tally tree within 30 ft of a tree 

or stump that has a root disease to which 

the tally tree is susceptible 

Live tally tree with signs or symptoms 

diagnostic for root disease such as 

characteristic decay, stain, ectotrophic 

mycelia, mycelial fans, conks or excessive 

resin flow at the root collar. No visible 

crown deterioration. 

Live tally tree with signs or symptoms 

diagnostic for root disease such as 

characteristic decay, stain, ectotrophic 

mycelia, mycelial fans, conks, or excessive 

resin flow at the root collar. Visible crown 

deterioration such as thinning chlorotic 

foliage, reduced terminal growth, and/or 

stress cones. 

61 Annosus root disease 

62 Armillaria root disease 

63 Black stain root disease 

65 Laminated root rot 

 66 Port-Orford-cedar root 

disease 

 

 

 Code Agent Code Severity 

White pine 

blister rust: 

 

36 White pine blister rust 1 Branch infections located more than 

2.0 feet from tree bole. 

 2 Branch infections located 0.5 to 2.0 feet 

from bole. 

 3 Bole infections present, Or: branch 

infections within 0.5 feet of bole 

 Code Agent Code Severity 

Sudden oak 

death 

(tanoak, 

coast live 

oak, black 

oak): 

 

 31 Sudden oak death symptoms 1 Bleeding present on bole 

 2 Bleeding present on bole and adjacent 

mortality present 

 3 Laboratory confirmed sudden oak death 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix H 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 325

Class II Agents 

Agents Severity 

 Code Agent Code Severity 

Other 

insects: 

 

 20 General 1 

2 

Bottlebrush or shortened leaders, 0-2 

forks on the tree's stem, Or: <20% of the 

branches affected, Or: <50% of the bole 

has visible larval galleries. 

3 or more forks on the tree's bole, Or: 

20% or more of the branches are 

affected, Or: the terminal leader is dead, 

Or: ≥50% of the bole has visible larval 

galleries. 

 21 Shoot moths 

 22 Weevils 

 23 Wood borers 

24 Balsam wooly adelgid 

(aphid) 

25 Sitka spruce terminal weevil 

 

 Code Agent Code Severity 

Stem-branch 

cankers: 

 

 33 Diplodia blight 1 Branch infections present. <50% of the 

 40 General/other crown affected 

41 Western gall rust (Pinus 

ponderosa, Pinus contorta) 

 2 Branch infections present. ≥50% of the 

crown affected, Or: any infection on the 

 42 Commandra blister rust bole. 

(Pinus ponderosa) 

43 Stalactiform rust (Pinus 

contorta) 

 

 44 Atropellis canker (Pinus 

spp.)

45 Cytospoa or Phomopsis 

(Pseudotsuga menziesii, 

Abies spp.) 

 

 Code Agent Code Severity 

Pitch 

canker: 

 

32 Pitch canker (CA Pinus

spp.) 

 1 No bole canker + <10 infected branch 

tips 

 2 No bole canker + ≥10 infected branch 

tips 

 3 1 or more bole cankers + <10 infected 

branch tips 

 4 1 or more bole cankers + ≥10 infected 

branch tips 

 Code Agent Code Severity 

Stem decays: 46 General/other 1 1 conk on the stem or present at ground 

 47 Red ring rot (Phellinus pini) level 

48 Indian paint rot 

(Echinodontium tinctorium) 

 2 2 or more conks separated by <16 feet 

on bole 

 49 Brown cubical rot 

(Phaeolus schweinitzii)

 3 2 or more conks separated by ≥16 feet 

on bole 

 4 No conks. Visible decay in the interior 

of the bole 

 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix H 

326 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Class II Agents 

Agents Severity 

Code Agent Code Severity 

Special 

agents: 

 

 50 Suppression No severity rating 

 51 Excessively deformed 

sapling 

 

 Code Agent Code Severity 

Foliar 

pathogens: 

 

 55 General/other 1 <20% of foliage affected, or <20% of 

 56 Rhabdocline (only on the crown contains brooms. 

Pseudotsuga menziesii) 

57 Elytroderma (only on Pinus 

ponderosa) 

 2 ≥20% of foliage affected, or ≥20% of 

the crown contains brooms. 

58 Broom rusts (only on Abies, 

Picea, and Juniperus 

occidentalis) 

59 Swiss needle cast (only on 

Pseudotsuga menziesii) 

 Code Agent Code Severity 

Animal 

agents: 

 

 70 Animal; general/unknown 1 <20% of the crown is affected. Bole 

damage is restricted to less than half of 

circumference. 

 71 Mountain beaver 

 72 Livestock 

73 Deer or elk 2 ≥20% of the crown is affected. Bole 

damage to half or more of 

circumference. 

 74 Porcupines 

75 Pocket gophers, squirrels, 

mice, voles, rabbits, hares 

 76 Beaver 

 77 Bear 

 78 Human (not logging) 

 Code Agent Code Severity 

Weather 

agents: 

 

 80 Weather; general/unknown 1 <20% of the crown is affected. 

 81 Windthrow or wind 

breakage 

 2 ≥20% of the crown is affected or any 

damage to the bole. 

82 Snow/ice bending or 

breakage 

83 Frost damage on shoots 

 84 Winter desiccation 

 85 Drought/moisture 

deficiency 

 

 86 Sun scald 

 87 Lightning 

 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix H 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 327

Class II Agents 

Agents Severity 

Code Agent Code Severity 

Physical 

injury: 

 

 90 Other; general/unknown 1 <20% of the crown is affected. 

 91 Logging damage 2 ≥20% of the crown is affected or any 

 92 Fire; basal scars or scorch damage to the bole. 

 93 Improper planting 

 94 Air pollution or other 

chemical damage 

 

 Code Agent Code Severity 

Physical 

defect: 

 

95 Unspecified physical defect 0 Severity is not rated 

 96 Broken/missing top 

 97 Dead top 

 98 Forks and crooks (only if 

caused by old top out or 

dead top) 

 

 99 Checks/bole cracks 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix I 

328 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Appendix I. FIA Inventories by State, Year, and Type

State code State name Date(s) of available periodic inventory data Initiation of annual inventory

1 Alabama 1972, 1982, 1990, 2000 2001 

2 Alaska 1998 2004 

4 Arizona 1985, 1999 2001 

5 Arkansas 1978, 1988, 1995 2000 

6 California 1994 2001 

8 Colorado 1984 2002 

9 Connecticut 1985, 1998 2003 

10 Delaware 1986, 1999 2004 

12 Florida 1970, 1980, 1987, 1995 2003 

13 Georgia 1972, 1982, 1989, 1987 1997 

16 Idaho 1991 2004 

17 Illinois 1985, 1998 2001 

18 Indiana 1986, 1998 1999 

19 Iowa 1990 1999 

20 Kansas 1981, 1994 2001 

21 Kentucky 1988 1999 

22 Louisiana 1974, 1984, 1991 2001 

23 Maine 1995 1999 

24 Maryland 1986, 1999 2004 

25 Massachusetts 1985, 1998 2003 

26 Michigan 1980, 1993 2000 

27 Minnesota 1977, 1990 1999 

28 Mississippi 1977, 1987, 1994 2006 

29 Missouri 1989 1999 

30 Montana 1989 2003 

31 Nebraska 1983, 1994 2001 

32 Nevada 1989 2004 1

33 New Hampshire 1983, 1997 2002 

34 New Jersey 1987, 1999 2004 

35 New Mexico 1987, 1999 

36 New York 1993 2002 

37 North Carolina 1984, 1990, 2002 2003 

38 North Dakota 1980, 1995 2001 

39 Ohio 1991 2001 

40 Oklahoma 1989 (central/west), 

1976, 1986, 1993 (east) 2008 (east) 

41 Oregon 1992, 1999 2001 

42 Pennsylvania 1989 2000 

44 Rhode Island 1985, 1998 2003 

45 South Carolina 1968, 1978, 1986, 1993 1999 

46 South Dakota 1980, 1995 2001 

47 Tennessee 1980, 1989, 1999 2000 

48 Texas 1975, 1986, 1992 2001 

49 Utah 1993 2000 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix I 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 329

State code State name Date(s) of available periodic inventory data Initiation of annual inventory

50 Vermont 1983, 1997 2003 

51 Virginia 1977, 1985, 1992 1998 

53 Washington 1991, 2001 2002 

54 West Virginia 1989, 2000 2004 

55 Wisconsin 1983, 1996 2000 

56 Wyoming 1984, 2000 

72 Puerto Rico 2001, 2002, 2003, 2004 

78 US Virgin Islands 2004 

1

 insufficient funding to continue annual inventory after 2005 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix J 

330 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Appendix J. Biomass Estimation in the FIADB 

In previous versions of the FIADB, a variety of regional methods were used to estimate tree 

biomass for live and dead trees in the TREE table. In FIADB 4.0, a new nationally consistent 

method of estimating tree biomass has been implemented. This new approach, called the component 

ratio method (CRM) (Heath and others 2009), involves calculating the dry weight of individual 

components before estimating the total aboveground or belowground biomass. The CRM approach 

is based on: 

• converting the sound volume of wood (VOLCFSND) in the merchantable bole to biomass 

using a compiled set of wood specific gravities (Miles and Smith 2009) (see REF_SPECIES 

table for values) 

• calculating the biomass of bark on the merchantable bole using a compiled set of percent bark 

estimates and bark specific gravities (Miles and Smith 2009) (see REF_SPECIES table for 

values) 

• calculating the biomass of the entire tree (total aboveground biomass), merchantable bole 

(including bark), and belowground biomass, using equations from Jenkins and others (2003) 

• calculating the volume of the stump (wood and bark) based on equations in Raile (1982) and 

converting this to biomass using the same specific gravities used for the bole wood and bark 

• calculating the top biomass (tree tip and all branches) by subtracting all other biomass 

components from the total aboveground estimate 

• calculating an adjustment factor by developing a ratio between bole biomass calculated from 

VOLCFSND to bole biomass using equations from Jenkins and others (2003) 

• applying the adjustment factor to all tree components derived from both Jenkins and Raile 

The CRM approach is based on assumptions that the definition of merchantable bole in the volume 

prediction equations is equivalent to the bole (stem wood) in Jenkins and others (2003), and that the 

component ratios accurately apply. 

The tables in this appendix describe the equations used in FIADB 4.0 to estimate components of 

tree biomass, including stem wood (bole), top and branches combined, bark, stump, and coarse 

roots. Most of these components are estimated through a series of ratio equations as described by 

Jenkins and others (2003). Stem wood biomass is calculated directly from the sound cubic-foot 

volume of the tree bole, percentage of bark on the bole, and specific gravities of both wood and 

bark. 

The individual component biomass values for bole, top, and stump are not available in FIADB for 

sapling-size timber tree species and all woodland tree species. Because saplings (trees from 1 to 4.9 

inches in diameter) have no volume in FIADB, a ratio method was developed to compute a factor 

that is applied to saplings based on diameter and species, and the result is stored in 

DRYBIO_SAPLING. For woodland species (trees where diameter is measured at the root collar 

[DRC]), volume is calculated from the root collar to a 11⁄2-inch top diameter. Because this volume 

accounts for a larger portion of the tree than timber species volume equations do, it was determined 

that the top and stump equations were not applicable to woodland species. Woodland tree volume is 

converted to biomass and stored in DRYBIO_WDLD_SPP, which is an estimate for total 

aboveground biomass, excluding foliage, the tree tip (top of the tree above 11⁄2 inches in diameter), 

and a portion of the stump from ground to DRC. Therefore, only total aboveground and 

belowground biomass values are estimated for saplings and woodland species. 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix J 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 331

Definitions of each biomass component and the equations used to estimate the oven-dry weight in 

pounds are shown in appendix tables J-1 through J-4. 

• Appendix table J-1 defines the columns that are stored in the TREE table, and clarifies the set 

of trees (species, dimensions, live or dead, etc) that are used in each calculation. 

• Appendix table J-2 defines the Jenkins component equations and explains how the equation 

results are used to estimate biomass. The ‘Estimate name’ in this table is the same name found 

in the coefficient definitions described in the biomass-related columns 38 to 49 of the 

REF_SPECIES table. 

• Appendix table J-3 contains the Jenkins equations used to estimate each biomass component. 

The equations use the exact coefficient column names found in the REF_SPECIES table (for 

example, JENKINS_TOTAL_B1 in appendix table J-3 is the column name in REF_SPECIES 

that holds the value of the coefficient needed in the total aboveground biomass equation). The 

Jenkins equations use the measured tree diameter to produce an estimate. 

• Appendix table J-4 contains the actual equations used in the FIADB to estimate the biomass 

components stored in the TREE table. These equations are a blend of Jenkins ratios, calculated 

bole biomass (based on calculated volume from the TREE table), and adjustment factors. The 

adjustment factor is an important step because it relates measurement-based bole biomass 

(DRYBIO_BOLE) to generalized equation-based bole biomass to improve or adjust the 

computed results of the Jenkins equations. 

For more information please consult the publication by Heath and others (2009), titled 

Investigation into Calculating Tree Biomass and Carbon in the FIADB Using a Biomass Expansion 

Factor Approach. 
 FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix J 

332 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

Appendix table J-1. Definition of Biomass Components stored in the TREE table. 

Component Column name Biomass Component Definition 

(all are oven-dry biomass, pounds) 

Merchantable stem (bole) DRYBIO_BOLE Merchantable bole of the tree, includes stem wood and 

bark, from a 1-foot stump to a 4-inch top diameter. Based 

on VOLCFSND and specific gravity for the species. For 

timber species with a DIA ≥5 inches. Includes live and 

dead trees. 

(Note that VOLCFGRS or VOLCFNET might be used after 

adjustment based on national averages, if VOLCFSND is 

not available.) 

Top DRYBIO_TOP Top of the tree above 4 inches diameter and all branches; 

includes wood and bark and excludes foliage. For live and 

dead timber species with a DIA ≥5 inches. 

Stump DRYBIO_STUMP Stump of the tree, the portion of a tree bole from ground to 

1 foot high, includes wood and bark. For live and dead 

timber species with a DIA ≥5 inches. 

Belowground DRYBIO_BG Coarse roots of trees and saplings with a DIA ≥1 inch. For 

timber and woodland species, and live and dead trees. 

Saplings DRYBIO_SAPLING Total aboveground portion of live trees, excluding foliage. 

For timber species with a DIA ≥1 inch and <5 inches. 

Woodland tree species DRYBIO_WDLD_SPP Total aboveground portion of a tree, excluding foliage, the 

tree tip (top of the tree above 11⁄2 inches in diameter) and a 

portion of the stump from ground to DRC. For live and 

dead woodland species with a DIA ≥1 inch. Woodland 

species can be identified by REF_SPECIES.WOODLAND 

= X, TREE.DIAHTCD = 2, or TREE.WDLDSTEM >0 
FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix J 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 333

Appendix table J-2. Jenkins Biomass Component Equation Definitions 

(Refer to the REF_SPECIES table for equation coefficients and adjustment factors).

Component Estimate name Definition 

Total aboveground biomass total_AG_biomass_ 

Jenkins 

Total biomass (oven-dry, pounds) of the 

aboveground portion of a tree. Includes stem wood, 

stump, bark, top, branches, and foliage. 

Stem wood biomass ratio stem_ratio 

A ratio that estimates biomass of the merchantable 

bole of the tree by applying the ratio to 

total_AG_biomass_Jenkins. Includes wood only. 

This is the portion of the tree from a 1-foot stump 

to a 4-inch top diameter. 

Stem bark biomass ratio bark_ratio 

A ratio that estimates biomass of the bark on the 

merchantable bole of the tree by applying the ratio 

to total_AG_biomass_Jenkins. 

Foliage biomass ratio foliage_ratio 

A ratio that estimates biomass of the foliage on the 

entire tree by applying the ratio to 

total_AG_biomass_Jenkins. 

Coarse root biomass ratio root_ratio 

A ratio that estimates biomass of the belowground 

portion of the tree by applying the ratio to 

total_AG_biomass_Jenkins. 

Stump biomass stump_biomass 

An estimate of the stump biomass of a tree, from 

the ground to 1 foot high. Uses a series of equations 

that first estimates the inside and outside bark 

diameters, then estimates inside and outside bark 

volumes (Raile 1982). Wood and bark volumes are 

converted to biomass using specific gravity for the 

species. 

Sapling biomass adjustment JENKINS_SAPLING

_ADJUSTMENT 

An adjustment factor that is used to estimate 

sapling biomass for the tree by applying the factor 

to the total aboveground estimate, excluding 

foliage. The adjustment factor was computed as a 

national average ratio of the DRYBIOT (total dry 

biomass) divided by the Jenkins total biomass for 

all 5.0-inch trees, which is the size at which 

biomass, based on volume, begins. This is used on 

timber and woodland species. 
Appendix table J-3. Jenkins Biomass Equations (Actual B1 and B2

334

 coefficients and adjustment factors are stored in the 

REF_SPECIES table.) Note: these equations are used in appendix table J-4 to estimate the biomass components stored in the TREE table. 

Component Equation total_AG_biomass_Jenkins

(pounds) (total aboveground biomass, includes wood and bark for stump, bole, top, branches, and foliage) 

= exp(JENKINS_TOTAL_B1 + JENKINS_TOTAL_B2 * ln(DIA*2.54) ) * 2.2046 

stem_ratio = exp(JENKINS_STEM_WOOD_RATIO_B1 + JENKINS_STEM_WOOD_RATIO_B2 / (DIA*2.54) ) bark_ratio = exp(JENKINS_STEM_BARK_RATIO_B1 + JENKINS_STEM_BARK_RATIO_B2 / (DIA*2.54) ) foliage_ratio = exp(JENKINS_FOLIAGE_RATIO_B1 + JENKINS_FOLIAGE_RATIO_B2 / (DIA*2.54) ) root_ratio = exp(JENKINS_ROOT_RATIO_B1 + JENKINS_ROOT_RATIO_B2 / (DIA*2.54) ) stem_biomass_Jenkins (pounds) = total_AG_biomass_Jenkins * stem_ratio bark_biomass_Jenkins (pounds) = total_AG_biomass_Jenkins * bark_ratio bole_biomass_Jenkins (pounds) = stem_biomass_Jenkins + bark_ biomass_Jenkins foliage_biomass_Jenkins (pounds) = total_AG_biomass_Jenkins * foliage_ratio root_biomass_Jenkins (pounds) = total_AG_biomass_Jenkins * root_ratio stump_biomass (pounds) 

Volumes of wood and bark are based on diameter inside bark (DIB) and DOB equations from Raile 1982. 

DIB = (DIA * RAILE_STUMP_DIB_B1) + (DIA * RAILE_STUMP_DIB_B2 * (4.5-HT) / (HT+1)) 

DOB = DIA + (DIA * RAILE_STUMP_DOB_B1 * (4.5-HT) / (HT+1)) Volume is estimated for 0.1ft (HT) slices from ground to 1 foot high (HT), and summed to compute stump volume. Bark_volume = Volume_outside_bark – Volume_inside_bark Bark and wood volumes are multiplied by their respective specific gravities and added together to estimate biomass 

top_biomass_Jenkins (pounds) = total_AG_biomass_Jenkins – stem_biomass_Jenkins – bark_biomass_Jenkins – foliage_biomass_Jenkins – stump_biomass_Jenkins 

334 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix J 
335

Appendix table J-4. Equations used to calculate Biomass Components stored in the TREE table 

Column name Equation (refer to Appendix table J-3 for details on variables found in equations below) 

AdjFac = DRYBIO_BOLE / bole_biomass_Jenkins 

AdjFac_woodland = DRYBIO_WDLD_SPP / (total_AG_biomass_Jenkins – foliage_biomass_Jenkins) 

DRYBIO_BOLE (wood and bark) (see note below) (timber species only) 

VOLUME = VOLCFSND (or VOLCFGRS, VOLCFNET that are adjusted for the percent sound) Volume = includes the volume of wood from a 1-foot stump to a 4-inch top diameter = (VOLUME * (BARK_VOL_PCT / 100.0) * (BARK_SPGR_GREENVOL_DRYWT * 62.4) ) + 

 (VOLUME * (WOOD_SPGR_GREENVOL_DRYWT * 62.4) ) 

DRYBIO_TOP (timber species only) = top_biomass_Jenkins * AdjFacDRYBIO_STUMP (timber species only) = stump_biomass * AdjFacDRYBIO_SAPLING (timber species only) = (total_AG_biomass_Jenkins – foliage_biomass_Jenkins) * JENKINS_SAPLING_ADJUSTMENT DRYBIO_WDLD_SPP (woodland species only) 

Woodland species are identified by REF_SPECIES.WOODLAND = X, TREE.DIAHTCD = 2, and/or TREE.WDLDSTEM >0 For woodland species, volume equations produce volume of wood and bark, from DRC to a 11⁄2-inch top diameter, and includes branches. Biomass equations for each component are not available, therefore stem volume is converted 

to biomass and stored in DRYBIO_WDLD_SPP. This is an estimate of total aboveground biomass for woodland 

species, which includes wood and bark for the stem and branches and excludes foliage, the tree tip (top of the tree above 11⁄2 inches in diameter), and a portion of the stump from the ground to the point of diameter measurement. For trees with a DRC ≥5 inches: VOLUME = VOLCFSND (or VOLCFGRS, VOLCFNET that are adjusted for the percent sound) VOLUME = includes the volume of wood, bark, and branches Wood and bark volumes need to be separated before converting to biomass as follows: = (VOLUME * (BARK_VOL_PCT / 100.0) * (BARK_SPGR_GREENVOL_DRYWT * 62.4)) +  ((VOLUME – (VOLUME * (BARK_VOL_PCT / 100.0))) * (WOOD_SPGR_GREENVOL_DRYWT * 62.4)) 

For trees with a DRC <5 inches: 

= (total_AG_biomass_Jenkins – foliage_biomass_Jenkins) * JENKINS_SAPLING_ADJUSTMENT 

FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix J 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010 335
336

Column name Equation (refer to Appendix table J-3 for details on variables found in equations below) DRYBIO_BG (timber and woodland species) 

= root_biomass_Jenkins * AdjFac (for timber spp 

≥5 inches DBH) 

= root_biomass_Jenkins * JENKINS_SAPLING_ADJUSTMENT (for timber species <5 inches DBH) = root_biomass_Jenkins * AdjFac_woodland (for woodland species 

≥1 inch DRC) 

Note: If DIA 

≥ 5.0 and VOLCFSND >0 then VOLUME = VOLCFSND 

If DIA 

≥ 5.0 and VOLCFSND = (0 or null) and VOLCFGRS >0 then VOLUME = VOLCFGRS * Percent Sound 

If DIA 

≥ 5.0 and VOLCFSND and VOLCFGRS = (0 or null) then VOLUME = VOLCFNET * (Average ratio of cubic foot sound to cubic foot net volume, 

calculated as national averages by species group and diameter)

FIA Database Description and Users Manual for Phase 2, version 4.0 

Appendix J

336 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-245. 2010

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Rocky

 Mountain

 Research Station

The Rocky Mountain Research Station develops scientific information 

and technology to improve management, protection, and use of the 

forests and rangelands. Research is designed to meet the needs of 

the National Forest managers, Federal and State agencies, public and 

private organizations, academic institutions, industry, and individuals. 

Studies accelerate solutions to problems involving ecosystems, range, 

forests, water, recreation, fire, resource inventory, land reclamation, 

community sustainability, forest engineering technology, multiple use 

economics, wildlife and fish habitat, and forest insects and diseases. 

Studies are conducted cooperatively, and applications may be found 

worldwide.

Station Headquarters

Rocky Mountain Research Station

240 W Prospect Road

Fort Collins, CO 80526

(970) 498-1100

Research Locations

Reno, Nevada

Albuquerque, New Mexico

Rapid City, South Dakota

Logan, Utah

Ogden, Utah

Provo, Utah

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its 

programs and activities on the basis of race, color, national origin, age, disability, 

and where applicable, sex, marital status, familial status, parental status, religion, 

sexual orientation, genetic information, political beliefs, reprisal, or because all 

or part of an individual’s income is derived from any public assistance program. 

(Not all prohibited bases apply to all programs.) Persons with disabilities who 

require alternative means for communication of program information (Braille, 

large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 

720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, 

Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, 

DC 20250-9410, or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA 

is an equal opportunity provider and employer.

Flagstaff, Arizona

Fort Collins, Colorado

Boise, Idaho

Moscow, Idaho

Bozeman, Montana

Missoula, Montana