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Linda Joyce
Rocky Mountain Research Station
240 West Prospect
Fort Collins, CO 80526
Phone: 970-498-2560
 United States Department of Agriculture Forest Service.USDA logo which links to the department's national site.Forest Service logo which links to the agency's national site.

(click on images to enlarge)
Basic tree ring sample preparation techniques for aging aspen. Techniques may be applied to any tree species.
Materials and equipment needed to prepare samples for tree ring identification.
Fehling's solution is a staining formula I used in enhancing tree ring identification. It is a product of Forest Products Laboratory, Madison, Wisconsin. It appeared in an article in 1962 entitled "Color Tests for Differentianting Heartwood and Sapwood in certain softwood tree species. USDA Forest Service, Report No. 2246." Fehling's Solution is 3.5g copper sulfate, 17.3g potassium sodium tartrate, 6.0g sodium hydroxide with 100.0 ml water. Brush on after sanding sample and leave dry overnight.
A microscope mounted to a table with a movable top provided us with the technique to identify tree rings and measure their widths from tree cross sections. Data is automatically transferred to a computer file. 
Cross section of ponderosa pine showing growth release in response to thinning. Picture is credited to W.K. Olsen, 1998 Advanced Forestry.

Brown, Peter M., Shepperd, Wayne D., Brown, Christopher C., Mata, Stephen A., and McClain, Douglas L.  1995.  Oldest Known Engelmann Spruce.  Research Note RM-534, pg. 1-6.

Peter M. Brown, Wayne D. Shepperd, Stephen A. Mata, and Douglas L. McClain. 1998. Longevity of Windthrown Logs in a Subalpine Forest of Central Colorado. Can. J. For. Res. 28: 932-936.


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