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Tree Census and a Wealth of Public Data

Posted by Andrew Avitt, USDA Forest Service, Office of Communications in Forestry
Jul 29, 2021
Summer Dunn looking at mountains
Summer Dunn, a data collection team leader with FIA, currently oversees the data collection efforts of approximately 70 crewmembers across Washington, Oregon and California. Forest Service Photo/Summer Dunn

As our country sets out on the monumental task of conducting the U.S. census, the USDA Forest Service is conducting a census of its own – the Forest Inventory and Analysis (FIA).

Researchers conducting the FIA, also known as “America’s tree census,” measure trees, collect data and catalogue sample areas in research plots all over the U.S.

According to FIA, currently, there are nearly 300 billion trees in the United States. But the program does more than just count trees. There are also several other measurements being gathered; a 580-page manual worth of measurements to be exact.

“The data tells a story,” said Greg Reams, national program lead with the Forest Inventory and Analysis team. “Categories of data we collect include land use change into and out of forest land, soils work, carbon sequestration, and tracking wood that is on the ground, information which is critical for fire modelers to calculate wildfire risk ratings.”

After locating the plot using aerial imagery, crews often hike for miles through difficult terrain just to get to the site. Once there, crew members measure the trees and catalogue damage from invasive species, fire and weather events. Crew members also measure dead trees, downed material and understory vegetation, which can act as wildlife habitat as well as fuel for wildfire.

FIA also surveys land owners who have larger tracks of land. One example of this data collection is the National Woodland Owner Survey, which captures landowner perspectives and plans for the future. This data, combined with the FIA, helps land managers and others build models of what a forest might look like in the next 10 to 50 years.

Altogether, the FIA gives land managers and landowners the tools they need to plan for the long-term. As the FIA dataset grows each year, its user base will grow along with it, and use this wealth of public data to maintain and improve conditions on the nation’s forests.

Category/Topic: Forestry

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Michael G Apicello
Aug 09, 2020

Is this inventory occurring in curry county, Oregon? Northwest loop of the Klamath Knot? Thanks — Mike Apicello;USFS (Ret’d).

Ben Weaver
Aug 10, 2020

@Michael G Apicello - Hello Mike, thanks for your question. Yes, all plots associated with the Forest Inventory and Analysis (FIA) program occur approximately every 6,000 acres, across the contiguous United States as well as in Alaska and U.S. territories. So if there are forests in Curry County, then FIA is there collecting data. Due to confidentiality, exact locations of research plots cannot be disclosed. Thank you.