A density management diagram for even-aged ponderosa pine stands

We developed a density management diagram (DMD) for ponderosa pine using Forest Inventory and Analysis (FIA) data. Analysis plots were drawn from all FIA plots in the western United States on which ponderosa pine occurred. A total of 766 plots met the criteria for analysis. Selection criteria were for purity, defined as ponderosa pine basal area >= 80% of plot basal area, and even-agedness, as defined by a ratio between two calculations of stand density index. The DMD is relatively unbiased by geographic area and therefore should be applicable throughout the range of ponderosa pine. The DMD is intended for use in even-aged stands, but may be used for uneven-aged management where a large-group selection system is used. Examples of density management regimes are illustrated, and guidelines for use are provided.