New Method for Determining the Relative Stand Density of Forest Inventory Plots

Determining the relative density of Forest Inventory and Analysis plots is complicated by the various species and tree size combinations in the Nation?s forested ecosystems. Stand density index (SDI), although developed for use in even-aged monocultures, has been used for stand density assessment in largescale forest inventories. To improve application of SDI in uneven-aged, mixed species stands present in large-scale inventories, a model was developed whereby a stand?s maximum SDI was a function of the stand?s mean specific gravity (SG) of individual trees. A strong relationship was found between the mean SG of all trees in a stand and the 99th percentiles of the observed distribution of stand SDIs. A model is proposed whereby the mean SG of individual trees in a stand serves as a predictor of a stand?s maximum stocking potential, regardless of the stand?s diameter distribution and species composition.