Forest Inventory and Analysis - Overview

Since 1930, the U.S.D.A. Forest Service has been surveying, analyzing and reporting on the health and productivity of America's forests, including those in Wisconsin. Known as the Forest Inventory and Analysis (FIA) [exit DNR], the program serves as the nation's and the state's forest census.

Fieldwork for the sixth survey of Wisconsin's 16 million acres of forestlands was completed in 2004. We invite you to view the highlights from this most recent inventory and explore these pages to learn more about the FIA.

FIA Mission

The FIA program provides scientifically credible information on how much forest exists, where it is located, how it is changing, who owns it, and how quickly trees and other vegetation are growing, dying and being harvested. The FIA also combines this information with related data on insects, diseases, and other types of stressors to evaluate forest health and future risks to our forests.

FIA information is then used for purposes such as assessing wildlife habitat and ecosystem stability, and planning and decision-making by public and private landowners. Most importantly, the data play an essential role in determining whether current forest management practices and policies are sustainable and thus able to preserve America's forestlands for future generations. Read more about the uses of FIA data.

Wisconsin's FIA

In partnership with the Department of Natural Resources Division of Forestry, the Forest Service completed five previous inventories of Wisconsin's forest resources in 1938, 1956, 1968, 1983 and 1996. In 2000, the two agencies began field measurements for the sixth inventory of Wisconsin's forestlands, which is now complete.

That same year, the agencies initiated a new annual inventory system in which 20 percent, or one-fifth, of the state's FIA field plots are measured each year. A full inventory of Wisconsin's forests therefore takes five years to complete. Now that all of the FIA field plots in Wisconsin have been inventoried once under the new system, the DNR and Forest Service have begun re-measuring the plots on a five-year rotating basis. For example, plots measured in 2000 were inventoried again in 2005. Read more about FIA methods in Wisconsin.