Tongass National Forest

Timber volume classes (VCs 4, 5, 6, 7 in the GIS TIMTYP layer) have been deemed statistically invalid for determining timber volumes. The Forest Plan made adjustments in its volume mapping strategy which now includes high, medium, and low volume strata. From a wildlife habitat mapping standpoint in old growth stands of timber, use of the original volume class mapping is a reasonable tool for the purpose of identifying structure and gaps versus volume. Some may be confusing the 2 different uses of the volume class mapping.

Caouette’s vegetation structure assessment looks at stand structure and coarse canopy structure in an inventory format that can supply better information for wildlife models. The high volume, coarse canopy component, or big-tree forests, is based primarily on the old volume class 6 and 7 mapping. This has been determined to be a reasonable representative mapping tool for this type of wildlife habitat mapping and employees have been directed to use it for appropriate planning analyses.

Testing and assessment of the overall vegetative structure mapping is ongoing. Future uses of this tool will be determined and implemented as appropriate.

Use of the high volume, course canopy (volume classes 6 and 7) will continue on old growth habitat assessments and analyses as directed by Forest Supervisor letter.

Complete the testing and assessment of the Caouette vegetation structure assessment Include in that assessment options for use relative to vegetation mapping, the use for relationships to models, and use for timber volume mapping.

• Colleen Grundy
• John Caouette
• Patti Krosse

• A report with recommendations including policy adjustments (Handbook Supplement)