A density management diagram for even-aged Sierra Nevada mixed-conifer stands

Abstract

We have developed a density management diagram (DMD) for even-aged mixed-conifer stands in the Sierra Nevada Mountains using forest inventory and analysis (FIA) data. Analysis plots were drawn from FIA plots in California, southern Oregon, and western Nevada which included those conifer species associated with the mixed-conifer forest type. A total of 204 plots met the selection criteria for analysis, which were for even-agedness and species composition. Even-agedness was characterized by a ratio between two calculations of stand density index. Species composition included admixtures of the species characterizing the Sierra Nevada mixed-conifer type with up to 80% of stand basal area contributed by ponderosa and Jeffrey pines. The DMD is unbiased with respect to species composition and therefore should be broadly applicable to the mixed-conifer type. 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.