Forest Inventory & Analysis (FIA)

The Georgia Forestry Commission (GFC), in coordination with the U.S. Forest Service currently conducts ongoing forest inventory measurements throughout Georgia. The purpose is to periodically gather land and forest resource data from a series of permanent sample plots in order to assess current forest resource status and trends in Georgia. This forest inventory system enables GFC staff to provide guidance and assistance to the existing forest industry and prospective industries in sustainable utilization of Georgia's renewable forest resources.


FIA Data Collection Facts

  • Sample plots are established throughout Georgia at a density of about 1 plot per 6000 acres. They have been selected randomly, without regard to current land use, ownership, location, or land use changes which may have occurred since the previous inventory.
  • Twelve Georgia Forestry Commission Foresters work full time to collect this data.
  • An effort is made to contact and secure landowner permission prior to plot measurement by FIA foresters. In some cases, prior landowner contact cannot be made.
  • Approximately twenty percent (20%) of the sample plots are measured each year and all sample plots are measured within a 5-year period.
  • Data includes species composition and diversity, live wood and biomass volumes, wood growth and removals, forest health, insect and disease impact, past natural and man-caused disturbances, land use changes (i.e. conversion of land areas from forest to non-forest and vice versa), and many other types of data.
  • Data collection does not affect property taxes, nor will it limit in any way, the land use options of the landowner.
  • Plots are not clearly marked in an effort to avoid influencing any land management decisions/activities since each one is a representative snapshot of our forests at the time of measurement.

Landowner cooperation for our data collection is greatly appreciated.


FIA Data Use

Collected data is electronically compiled and forwarded to the U.S. Forest Service FIA program office in Knoxville, Tennessee. Approximately 20% of the sample plots are collected each year and data compilation is performed each year on the last five years of measurements across all plots. This provides a 5-year rolling average for data parameters. The data is compiled into county, regional, and state summaries and as well as made available on the online FIA database shown at Forest Inventory Data Query Tools.

When using FIA data, the GFC recommends:

  • Professional foresters, with FIA data experience, provide further analysis and data interpretation for private companies and other organizations with limited forestry backgrounds. Contact the GFC Forest Utilization staff for more information on FIA data use for industry. (Risher Willard, Email: rwillard@gfc.state.ga.us, Phone: 912-655-2104)

  • FIA data users should review the definition of terms beginning on page 7 of the FIA Statistics Report for Georgia at http://www.srs.fs.usda.gov/pubs/rb/rb_srs036.pdf.

  • Consideration should be given to the sampling error for all FIA data queries:

    • Data queries for small areas should not be done.  A good rule of thumb for Georgia is to examine a geographic area that includes at least 20 counties, or a 50 mile radius of a given point.

    • Sampling errors tend to be small for general data queries and sampling error is larger for more detailed data queries. For example, a query of total pine growing stock volume has less error than an estimate of Longleaf pine growing stock volume in the 21-25 year age class.

FIA data can be used for estimating the following forest attributes within a given geographic area, including statewide:

  • Amounts of forestland and various forest types
  • Amounts of forestland in various ownership categories and ownership changes
  • Amounts of forestland in various age classes
  • Wildlife habitat potential using forest type and age class
  • Timber and forest biomass volumes
  • Timber growth and removal amounts
  • Other uses of FIA data are described in a Forest Service Fact Sheet at http://www.fia.fs.fed.us/library/fact-sheets/overview/FIA_Data_Uses.pdf


More Information:

Contact Forest Inventory & Analysis Staff


Resources



A special thanks to the USFS, our partner in conservation and protection, for providing funding.