The Forest Inventory and Analysis

Program: A Source

of Broad-scale

Data About BLM

Forestland

By Bill Williams, Forester

BLM, National Science and 

Technology Center

Background

The mission of the Forest Inventory and Analysis (FIA) program

of the U.S. Forest Service is to

“make and keep current a comprehensive inventory and analysis

of the present and prospective

conditions of and requirements

for the renewable resources of

the forest and rangeland of the

United States.” The FIA has

been in operation under various

names (e.g., Forest Survey, Forest Inventory and Analysis) for

about 70 years. This program,

which includes all forestland

within the United States, is

managed by the Research and

Development organization of

the U.S. Forest Service. An

inventory of Bureau of Land

Management lands is taken by

the FIA units at the Rocky

Mountain Research Station

(Fort Collins, Colorado) and

the Pacific Northwest

Research Station (Portland,

Oregon).

Discussion

The FIA provides status and

trend information about forest

area, location, and ownership.

State reports are published as

Resource Bulletins; occasionally,

reports cover a sub-State area.

Reports include information, by

species, on the size and number

of trees, wood volume, and

health of trees, as well as tree

growth, harvest removals, and

mortality. The program conducts

special surveys to determine

wood production and use rates in

various products within a State.

The FIA sampling procedure

consists of three phases. The

first is a remote-sensing phase in

which the land is classified into

forest and nonforest areas and

spatial measurements are taken

to determine fragmentation,

urbanization, and distance variables. Although aerial photography has traditionally been carried

out, satellite-imagery is now

frequently used.

In phase two, a set of field

sample locations is distributed

across the landscape, with one

sample location every 5,000

meters—about one plot every

2,430 ha (6,000 acres). Field

crews record measurements

and observations at the sample

locations.

Phase three consists of a subset of the phase-two plots—

about one plot every 38,880 ha

(96,000 acres). These plots are

visited during the growing season to collect an extended suite

of ecological data, including full

vegetation inventory, tree and

crown conditions, soil data,

lichen diversity, coarse woody

debris, and evidence of ozone

damage. Phase three is a relatively

recent addition to the program.

This enhanced program includes

information relating to tree

crown condition, lichen community composition, soils, ozone

indicator plants, complete vegetative diversity, and coarse woody

debris.

Historically, the FIA conducted

a complete inventory for each

State about every 10 years. The

Agricultural Research, Extension,

and Education Act of 1998

(Public Law 105-185), however,

directed all FIA units to switch

to an annual inventory system

in which they measure a portion

of the plots in each State each

year. The law requires more data

collection on a wider array of

parameters and requires analysis

and reporting for States at 5-year

intervals. The move to an annual system nationwide depends

on funding levels in the Federal

budget and on cooperator contributions. The present target

for western States is to measure 10% of the plots each year.

The status of the program and

additional information are

found on the FIA Web site at

http://fia.fs.fed.us/.

In the past, FIA data were primarily available through tables in

the published reports. Recently,

FIA created a database and a

Web site to provide custom

reports. You can create standard or custom output tables

by selecting options provided.

NO. 61 DATE 01/21/03

Range

Forestry

Resource Note 61

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For example, you can generate

tables showing acres of forestland

by forest type, stand size class,

and site class on BLM land in a

selected set of Counties in a

State. The tables available are for

nonreserved productive timberland—land capable of growing

more than 20 cubic feet per acre,

per year, of species considered

useful for wood products. The

table descriptions and options use

terminology associated with

the production of wood products. The Web site address is

http://www.ncrs.fs.fed.us/4801/

fiadb/.

The FIA is taking advantage of

developing technology to analyze

and present information in new

ways and to produce new products. The Interior West

Resources, Inventory, Monitoring, and Evaluation Program

(Rocky Mountain Research Station FIA) has combined digital

data sets—elevation, aspect,

slope, geology, precipitation, and

AVHRR- and TM-based vegetation cover types—with forest

inventory ground and photo

plots to produce map products of several forest attributes

for ecoregions in the Interior

West. These maps are generated

by modeling forest inventory

variables as functions of the

digital data.

Conclusion

The FIA, as a national, strategicscale program, does not provide

data for operational planning or

monitoring. A generalization,

based on one field sample location per 2,430 ha (6,000 acres),

is that a reasonably precise

estimate of forest growth,

mortality, or structure can be

produced for an area of

81,000 ha (200,000 acres). An

estimate for an area less than

that will probably lack the

precision desired. This is

presently a limitation for BLM

because of the ownership pattern and scattered distribution

of timberland and commercial

forestland. 

Nevertheless, the FIA provides

the only consistent inventory

data across administrative boundaries. The data can be considered

for assessing landscape scale—

particularly in areas adjacent to

National Forests—or in writing

land use plans for units having

extensive pinyon–juniper areas.

The new maps and spatial coverages are in formats that are

relevant and readily usable by

analysts and planners.

Contact

Bill Williams

National Science and Technology

Center

Denver Federal Center

Building 50

P.O. Box 25047

Denver, CO, 80225-0047

Phone: 303-236-0206

Fax: 303-236-3508

Email: Bill_Williams@blm.gov

Range

The Bureau of Land Management Resource Notes,

which are posted on this

Web site

(http://www.blm.gov/nstc/resourcenotes/resnotes.html),

are early announcements of technical and informational

topics for BLM personnel and their customers. Information

contained in this Resource Note has not been 

peer-reviewed. Conclusions and opinions expressed herein

do not necessarily represent those of BLM. Use of trade

names does not imply U.S. government 

endorsement of commercial products.

Technical Editor - Deborah Harris

(Debbie_Harris@blm.gov)

Science Editor - Brian St. George

(Brian_St_George@blm.gov)

Graphic Designer - Ethel Coontz (Ethel_Coontz@blm.gov)

If you would like to prepare a Resource Note

for electronic distribution, or if you have an idea or 

can suggest an author for a Resource Note, 

contact the Science Editor (e-mail:

Brian_St_George@blm.gov; phone: 303-236-1930) with

the topic and the name of the writer, including 

mailing address, phone number, and e-mail address.

Thank you for your interest in Resource NoteS.

Resource Note 61

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