Stand Volume and Growth:
Getting the Numbers

Steve Bowers, OSU Extension Forester, Lane County
Nate Coleman, OSU Extension Master Woodland Manager
Richard Fletcher, OSU Extension Forester, Linn and Benton Counties

This web-based OSU Extension publication explains how you can estimate the standing volume and annual growth of timber stands that are uniform in age, stand characteristics, and species. Estimates of volume and growth are helpful in planning when to harvest or how much to remove in a thinning operation. These estimates also can assist you with financial analysis and the tax implications involved in a timber harvest.

Don’t confuse the simplified procedure for collecting and analyzing tree volumes that we describe in this publication with the more complex and precise techniques that professional foresters use to estimate timber values for sales, land appraisals or legal purposes. Our system will allow you to get reasonably accurate gross volumes of timber, but will not address net volumes, log grades or monetary values.

Volume and growth numbers generated by any tree measuring system are estimates, and the system described in this publication works very well for most small woodland owners. In the interest of time and money, you usually can’t afford to measure all of your trees, so you’ll measure a few sample trees from your stand. You’ll use this sample of trees to obtain an index called a tarif number, which will be used to compute individual tree and stand volumes.

Of European origin, the tarif system was adapted for Pacific Northwest use by the State of Washington. The Tarif system shows the gross volume of trees, based on species, tree diameter, and total height. It’s one of several types of tree-volume tables. The tree-volume tables supported by this publication include Douglas-fir, grand fir, western hemlock, ponderosa pine, western red cedar and red alder.

If you have a question about the appropriateness of the tarif system for the management decisions of your timber stand – or if you need help with a complex situation – contact the Extension agent who serves your county, your State Service Forester, or a consulting forester.

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