Summary
Black cherry (Prunus serotina) is a key timber and wildlife species in the northern and Allegheny hardwood forests of northwestern Pennsylvania. In the past decade, it has become increasingly difficult to regenerate black cherry stands due to poor crown health and poor seed production. In the 1970s and 1980s, black cherry seed was produced every two to three years. With many stands now more than 90 years old, Forest Service scientists hypothesized stand age as a key factor affecting seed production. From 2010 to 2016, the scientists monitored seed production in two black cherry stands 70-plus years old, and two stands 110-plus years old. The older stands produced more seeds, averaging 508,733 seeds peracre, compared with 221,994 seeds per acre for the younger stands, which indicates that stand age may not be a factor in reduced seed production. Evidence did support erratic seed production as a factor in poor regeneration. Insects and diseases also play a role. The scientists are examining other factors that could affect seed production including poor pollination, a significant decrease in atmospheric nitrate inputs, and erratic weather. New research is testing the nitrate deposition hypothesis with annual calibrated fertilizer additions. All of these efforts are aimed at identifying key factors in poor regeneration of black cherry to help sustain this iconic and important species.
