A New Basis for Understory Stocking Standards for Partially Harvested Stands in the British Columbia Interior

Abstract

For partially harvested stands in the British Columbia interior, we present a new method for specifying regeneration stocking standards and a procedure for comparing achieved regeneration to the standard. Understory stocking is assessed in terms of the deviation from potential yield that the observed understory tree density represents. For a harvested area, the minimum stocking standard is stated as the maximum allowable mean deviation from potential. Deviation from potential is expressed on a relative (0–1) scale and predicted from overstory basal area and understory tree density. Because of a scarcity of calibration data, we undertook a crude, preliminary calibration of this relationship. As overstory basal area increases, the understory density required to achieve a given degree of understory stocking decreases. Issues pertaining to the stand management context and other approaches to regulating regeneration also are discussed. West. J. Appl. For. 20(1):5–12.

The Shelterwood Silvicultural System in British Columbia – A Practitioner’s Guide. Part 1: Implementation Considerations

“…Day (2007b) created a standard that combined the overstorey basal area and the understorey regeneration to declare the stand free-growing. Martin et al (2005) developed a means of estimating the deviation from potential volume growth (DFP) that allows a surveyor to declare whether there is a lack of both overstorey and understorey. This system would also provide an opportunity to develop a stocking standard for use with a shelterwood cut more heavily than 60% residual basal area.…”