Pro-B selection method for uneven-aged management of longleaf pine forests

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Interest in uneven-aged silviculture has increased since advent of ecosystem management programs, which place greater emphasis on ecological values and ecosystem services while also harvesting timber from the forest. However, traditional uneven-aged approaches (e.g., BDq) are often criticized as too complex, costly, and requiring highly-trained staff. The Proportional-B method (Pro-B) addresses these concerns, making uneven-aged silviculture a practical management option. In an operational-scale study, Pro-B was successfully used, by forest staff from a range of professional backgrounds, following less than 3 hours of training, to apply single-tree selection and group selection in longleaf pine (Pinus palustris Mill.) forests. Field crews achieved precision levels within 3 to 5 percent of the target residual basal area. By aggregating many diameter size-classes into only three size-class groups, Pro-B improves efficiency by requiring tree markers to remember only three fractions while making a single pass through the stand. Not being restricted by maximum-diameter rules also allows flexibility to retain larger trees for enhancing structural diversity. Trees of specific species and with good form, broad crowns and cavities can be retained, while adjusting spacing to release residuals. Systematic quantification of tree removal enables different individuals to obtain consistent results. A stable structure is maintained with characteristics of a mature forest, while regeneration is initiated and timber is removed through a periodic cutting cycle. With a focus on forest sustainability and flexibility to retain large trees and biological legacies by mimicking small-scale natural disturbances, Pro-B might be implemented to achieve the production objectives and stewardship goals of retention forestry.

  • Citation: Brockway, Dale G.; Loewenstein, Edward F.; Outcalt, Kenneth W. 2015. Pro-B selection method for uneven-aged management of longleaf pine forests. In: Holley, A. Gordon; Connor, Kristina F.; Haywood, James D., eds. Proceedings of the 17th biennial southern silvicultural research conference. e–Gen. Tech. Rep. SRS–203, Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station: 534-544.

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