Deconstructing the timber volume paradigm in management of the Tongass National Forest.

Caouette, John P.; Kramer, Marc G.; Nowacki, Gregory J. 2000. Deconstructing the timber volume paradigm in management of the Tongass National Forest. Gen. Tech. Rep. PNW-GTR-482. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 20 p. (Shaw, Charles G., III, tech. coord.; Conservation and resource assesments for the Tongass land management plan revision). Timber volume information and associated maps have been widely used in the Tongass National Forest for land-use planning and timber and wildlife management. Although considerable effort has been expended to improve timber volume maps, little has been done to evaluate the suitability of timber volume as a descriptor of forest character. We established a rough indicator of forest structure that uses trees per acre and quadratic mean diameter to examine the relation between timber volume and forest structure. Results indicated that timber volume and forest structure are not interchangeable attributes. Results also indicated that the original photinterpreted timber volume stratification did not always capture differences in timber volume but may have captured differences in forest structure. The recently revised timber volume stratification provides more reliable timber volume information, but it sacrifices structural information in the process.