Using OAF1 estimates to rank areas for supplemental planting

Supplemental planting (planting trees into areas of low stocking within young stands - also known as fill-planting, blanking, or beating) is a common silvicultural practice. This extension note describes a method to rank areas for supplemental planting based on the yield gain expected from the treatment. The method uses a modified Type 1 Operational Adjustment Factor (OAF1) survey and yield estimates from the stand growth model called TIPSY (Table Interpolation Program for Stand Yields). OAF1 is a TIPSY input parameter that reduces predicted yield to account for small stocking gaps in the stand and other yield-reducing factors. The procedures for the survey method and subsequent runs of the TIPSY computer model are briefly described. The method is evaluated by comparing it to a review of the supplemental planting literature and to results obtained from the stand growth model TASS (Tree and Stand Simulator), as well as by testing it in the field. The literature on supplemental planting indicates that the survival and growth of fill-planted trees increases as gap size increases, the size of pre-existing trees decreases, and the height growth rate of fill-planted trees increases. Limited comparisons to TASS suggest that when large differences in predicted gain separate the alternatives (e.g., differences