Equations for Predicting Merchantable Yield and Diameter Distribution for Lake States Red Pine

This article describes the construction and application of a stand-level merchantable yield equation for red pine in the Lake States. The equation predicts merchantable cubic foot volume for the stand based on minimum dbh and top size thresholds defined by the user. The merchantable yield equation can be used to model the merchandizing of user-defined products from stands given total stand volume, quadratic mean dbh, and the number of trees per acre. Also presented is an equation for estimating the distribution of trees per acre within a stand by dbh class. The equation predicts number of trees per acre larger than a specified dbh given the surviving number of trees per acre and mean dbh. The trees per acre equation can be used to describe the distribution of both diameter and basal area given number of trees per acre and quadratic mean dbh.