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FIA Frequently Asked Questions

Colorado FIA crew measuring in a tight space in the forest
What is FIA?

Forest Inventory & Analysis (FIA) is a U.S. Forest Service program that inventories and analyzes the nation’s public and private forests and their resources. Often referred to as the “Nation’s Forest Census,” the FIA program was mandated by Congress in the Farm Bill to provide annual forest inventories and state-level reporting. Since its inception in the McSweeny-McNary Act of 1928, the U.S. Forest Service’s “Forest Survey” (which later became the FIA program) has been collecting, analyzing, and reporting data on the status and trends of America’s forests.

FIA tracks key information such as:

  • The extent and location of forests
  • Ownership and how forests are being managed
  • The growth and health of trees and other vegetation
  • Changes in forest areas, including tree deaths, natural regeneration, and removals for products like lumber and firewood

This data is vital for a variety of purposes, including:

  • Assessing wildfire risk and studying the aftermath of fires
  • Evaluating the sustainability of ecosystem management practices
  • Supporting planning and decision-making for both public and private sector forest management

In 2014, the FIA program expanded to include the sampling of urban trees across various land-use types in select cities. The Colorado State Forest Service (CSFS) began conducting the Urban FIA program for Colorado in 2017. Recognizing the importance of including urban forests in the broader FIA framework, the U.S. Forest Service, along with state and local partners, is working towards a systematic approach for collecting and reporting urban tree data across all 50 states and territories.

For more information, visit the U.S. Forest Service FIA program website.

Explore our Urban FIA page for more information and FAQs at the bottom of the page.

FIA crews visit your property to measure several key aspects of your trees, including:

  • Diameter, height, foliage and other estimates of tree health and growth

They also assess various damage types that may affect your trees, such as:

  • Bark beetles – including mountain pine beetle, spruce beetle,and Ips beetles
  • Defoliators – such as western spruce budworm and various aspen defoliators
  • Chewing and sucking insects – including scale, aphids, moth larvae and more
  • Boring insects – such as emerald ash borer and poplar borer
  • Animal damage – caused by elk, deer, porcupines, bears, bison, sapsuckers, woodpeckers and domesticated animals
  • Abiotic damage – from natural events like drought, fire, flooding, frost, lightning, avalanches and wind
  • Diseases – including root diseases, cankers, heartwood rot, mistletoe, dieback, stem rusts and broom rusts
  • Human activities – such as damage from logging equipment, fencepost cuttings, etc.
  • Form defects – affecting lumber value, including forking, dead tops, crooks, sweeps and open wounds in bark

This comprehensive data helps assess the health, growth, and potential risks to your forest or trees over time.

Even if you don’t have trees on your property, our crews may still need to visit your location. Here’s why:

  • We evaluate sites that may have had trees in the past, even if they aren’t present now. This helps ensure we don’t miss areas that may have once supported trees but are currently barren or sparsely vegetated.
  • Our program uses a random sampling method to ensure data accuracy and avoid bias. Even properties without trees are essential to the overall representation of forest conditions across a region. By visiting every selected location, we prevent any statistical gaps that could distort the overall findings.
  • Locations are initially reviewed using satellite imagery, but some plants (like shrubs or cacti) can look similar to trees on the images. We visit the site to verify whether these are trees or other types of plants included in our survey, ensuring we accurately capture the right data.
  • Some species, such as pinyon pine, junipers/cedars and Gambel oak, are considered trees by our program, even if they are smaller or grow differently. These species are still part of our survey to ensure full representation of the area’s plant life.

By visiting your property, we confirm accurate data collection and avoid any statistical bias that could arise from overlooking areas without trees or misidentifying plant types. This ensures the integrity of the overall forest inventory.

Participation in this program is entirely voluntary, and it is entirely within your right to deny us access. However, permitting us to visit your property will add to the understanding of large-scale trends in natural resources in your county and state.

Yes. Either call/email/text the CSFS FIA employee that initially mailed or called you to schedule a date and time to visit your property.

Their contact information is either in the letter mailed to your address or you can call the CSFS field office closest to your property.

FIA plots are typically visited from April to December each year. We try to time location visits for when plots are clear of snow and/or flood waters and as conveniently as possible for landowners to avoid conflicts.

Each plot usually takes one day to complete but varies in the number of hours depending on complexity. CSFS FIA staff will not return to the same location for 10 or more years. If you own or manage a large ranch, your property could contain several FIA plots that we will request to visit in the following years.

U.S. Forest Service QA/QC staff may also contact you to ask permission for another visit in the same year (for quality control purposes).

No. You do not need to be present while a FIA crew visits your property. We contact landowners prior to visiting any property to confirm that we can access the exact location on the property.

We can also stop by a residence to discuss our work or talk to a ranch manager before we conduct our survey.

Yes. You can observe us working on the FIA plot at your property. We do warn landowners that some plots may be harder to access due to hiking on steep and rocky terrain. FIA crews are experienced in hiking long distances, at high elevations, and in a variety of weather conditions. We are required to visit the exact coordinates of the FIA plot and cannot move this to an easier location to access.

We use a variety of tools to conduct field measurements.

  • Compass
  • Flagging tape
  • Loggers tape
  • Increment borers
  • Rulers
  • Engineers tape measure
  • Hatchet​ and hammer
  • Aluminum nails and tags
  • Metal plot stakes
  • Laser range finder
  • Clinometer
  • Lumber crayon
Tools used by FIA technicians

We request that any gates that prohibit vehicles be unlocked for us to get as close as possible before hiking on foot to the FIA plot location. We routinely open and close locked gates that have keyed or combination locks. All lock combination codes are kept strictly confidential and are not recorded in any database. If you (or a representative) cannot be present to unlock gates, we can hike onto a property from the closest drivable location available.

Yes. We recommend landowners and property managers continue all tree/vegetation removals, trimming practices, or plantings they desire. It is an important aspect of the FIA program that FIA plots are not treated differently than the surrounding forest or urban area. Feel free to cut trees that have aluminum nails or tags on them, if you encounter these trees we included in our survey.

Yes. We recommend landowners and property managers to continue all herbicide and/or pesticide applications to the area that contains a FIA plot. Please inform the FIA crew visiting your property if a chemical treatment has been applied recently on the property.

No. All name or contact information that we collect will not be publicly available. Any mailing addresses that we initially contacted you through were sourced through county assessors. Phone numbers were researched through publicly available phonebook websites.

Yes. Data that we collect is put into the USFS-FIA database for further analysis and report production. This data is publicly available within several years of our visit. Exact FIA plot coordinates are kept confidential and only known by USFS and CSFS staff.

No. Data that we share publicly is not associated to any landowner name or contact information.

Plot location, ownership information, and private business information is barred from public release through the Freedom of Information Act: Exemption 3 Subsection (10) Forest and Rangeland Renewable Resources Act of 1978 (16 USC 1642(E)) and Exemption 4 “Confidentiality” (7 USC 2276 (D)(10)).

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