A new FIA-Type strategic inventory (NFI)

Abstract

New remote sensing technologies are now available to lower the cost of doing strategic surveys. A new sampling approach for the Forest Inventory and Analysis program (FIA) of the U.S.D.A. Forest Service is discussed involving a bi-sampling unit (BSU) that is composed of a field sample unit (FSU) centered within a large scale (1:1,000 to 1:3,000) photo sample unit (PSU) of the same size and shape. Within the PSU, a circular plot size is used for timber inventory and a strip plot for riparian buffer assessment and down woody material. On PSUs in previous studies in Alaska and Washington we counted or measured individual trees, tree height, crown area by digitizing the perimeter, plot crown closure, tree crown closure, tree branch density, plot area, and tree type (species and decay class). FSUs provide ground truth for PSUs as well as permanent and forest health plot information. Data for core FIA variables such as species, diameter, crown class, rotten/missing cull, and decay class may also be furnished by FSUs. National gross board foot volume per hectare estimates will be made from PSUs. Then permanent FSUs will provide growth, mortality, and defect factor information that are combined with the PSU estimates. Integration of PSUs with simultaneously collected Lidar data is used to improve tree height measurement accuracy in dense forest stands by providing local digital elevation models. Annual national estimates of stocking, mortality, and growth by tree species or forest type are obtained on a random sample chosen from a grid. Strata will be superimposed over this grid. The FSUs collected in the past will be incorporated in the new design which has the potential to result in a 50 percent reduction in cost relative to current FIA.

Parent Publication

• Monitoring Science and Technology Symposium: Unifying Knowledge for Sustainability in the Western Hemisphere

Citation

Grotefendt, Richard A.; Schreuder, Hans T. 2006. A new FIA-Type strategic inventory (NFI). In: Aguirre-Bravo, C.; Pellicane, Patrick J.; Burns, Denver P.; and Draggan, Sidney, Eds. 2006. Monitoring Science and Technology Symposium: Unifying Knowledge for Sustainability in the Western Hemisphere Proceedings RMRS-P-42CD. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 790-798