Proportional-B Method
This easy-to-learn method for selection silviculture overcomes many earlier objections about uneven-aged management, making it a practical and efficient option for forest managers. Field crews can mark stands, to a target basal area with high precision, using only a single marking pass, because tree size-classes are combined into three ecological and product-relevant categories.
Pro-B treated forest using single-tree selection
As they work, tree markers need at most to remember only three fractions (each a rate of tree removal for each category). This flexible method also allows managers to retain larger trees that improve structural diversity and wildlife habitat. Multiple species are easily accommodated and tree markers can leave the best cone producers, those with the best form or broad flattops, while removing those that appear likely to die soon and breaking up overly-dense clusters. Different individuals can apply the Pro-B Method and obtain consistent results. Pro-B provides guidance for maintaining a stable stand structure while allowing for the periodic removal of high-quality forest products on a 10 to 15-year cutting cycle.
Pro-B treated forest using group selection
Pro-B Calculator
Standard forest inventory data are easily entered into the yellow columns at the top left of the Pro-B Calculator, which is a spreadsheet with all needed formulas embedded. Marking guidelines needed to guide a particular forest to the specified target basal area are rapidly computed and displayed in green cells at the top center of the Pro-B Calculator. Forest stand condition is then displayed in both tabular and graphic formats.
Stand structure is shown graphically, both before and after thinning. Once the Pro-B Calculator becomes available at a website, anyone in the world with an internet connection can run their inventory data online and obtain guidance for managing their forest using the Pro-B Method.
Field Application of Pro-B
Early management experience indicates that Pro-B is a low-impact method (as perceived by members of the public), that fosters regeneration, maintains forest growth and conserves biological diversity in longleaf pine forest ecosystems. Its use in this and other forest types is expected to expand with time.
Pro-B treated forest blends well into a landscape
References
We have cooperated with Auburn University to create a website containing more information: Uneven-aged Silviculture: The Proportional Basal Area Method (Pro-B).
You can also view stories about the Pro-B Method on CompassLive.
- Brockway, D.G., Lowenstein, E.F., Outcalt, K.W. 2013. Pro-B selection method for uneven-aged management of longleaf pine forests. Biennial Southern Silviculture Research Conference. Southern Research Station, USDA Forest Service, Shreveport, Louisiana. March 2013. (Abstract)
- Brockway, D.G., Loewenstein, E.F. 2010. A new look at sustaining forests through uneven-aged management. In: Proceedings of the Annual Spring Natural Resources Symposium. Florida Chapter of the Society of American Foresters and School of Forest Resources and Conservation, University of Florida, Gainesville, Florida. June 2010. (Abstract)
- Brockway, D.G., Loewenstein, E.F., Outcalt, K.W. 2009. Applying the Proportional-B Selection Method in longleaf pine forests. In: Opportunities in a Forested World. Proceedings of the Annual Meeting of the Society of American Foresters, Orlando, Florida. October 2009. (Abstract)
- Loewenstein, E.F. 2009. Proportional-B: a simple but logical approach to marking single-tree selection. In: Opportunities in a Forested World. Proceedings of the Annual Meeting of the Society of American Foresters, Orlando, Florida. October 2009. (Abstract)
Contact Dale Brockway for more information on this topic.