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Abstract
The Forest Inventory and Analysis Database (FIADB) includes a large number of measured and computed variables. The definitions of measured variables are usually well-documented in FIA field and database manuals. Some computed variables, such as live basal area of the condition, are equally straightforward. Other computed variables, such as individual tree volume, require a more in-depth understanding of the FIA compilation system, such as how equations are selected based on species and plot location. For other computed variables, their derivation and meaning might not be clear to many users based on readily-available documentation. As a result, users may be prone to making their own assumptions about the meaning of these variables. This can be the case for users of the data and those who evaluate the use of FIA data, such as in the peer review process, where the value of certain variable can be debated. FIA stand age is one variable that is commonly used, but for which there is apparently disagreement about its meaning and usefulness. The “controversy” over this variable even exists with the FIA program, partly due to small differences in the way it is computed regionally or user experience with the variable in analysis. In this paper, the relationship between FIA stand age and other stand-level descriptors, such as composition, structure, and stand origin are explored. Some guidelines for the use of the variable, such as when it is appropriate to use it “straight”, and when other factors should be considered in analyses, will be presented.
Parent Publication
Citation
Shaw, John D. 2015. An evaluation of FIA's stand age variable. In: Stanton, Sharon M.; Christensen, Glenn A., comps. 2015. Pushing boundaries: new directions in inventory techniques and applications: Forest Inventory and Analysis (FIA) symposium 2015. 2015 December 8–10; Portland, Oregon. Gen. Tech. Rep. PNW-GTR-931. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. p 57.
