Do Pine Trees in Aspen Stands Increase Bird Diversity

In the Black Hills of South Dakota, quaking aspen (Populus tremuloides) is being replaced by conifers through fire suppression and successional processes. Al- though the Black Hills National forest is removing conifers (primarily ponderosa pine [Pinus ponderosa])toincreasetheaspencommunitiesinsomemixedstands,ForestPlan guidelines allow four conifers per hectare to remain to increase diversity in the remaining aspen stand. We compared bird species richness in pure ponderosa pine, mixed stands dominated by ponderosa pine with quaking aspen, mixed stands dominated by aspen with ponderosa pine, and pure aspen stands. Stands dominated by ponderosa pine had lower (