Pennsylvania sedge cover, forest management and Deer density influence tree regeneration dynamics in a northern hardwood forest

摘要

Pennsylvania sedge (Carex pensylvanica Lam.) is a native species that can form dense mats in the understory of northern hardwood forests. Resource managers suspect Pennsylvania sedge mats could limit tree regeneration, leading to changes in forest structure and composition. A number of other factors could alter the understory plant community, so any attempt to understand the effects of sedge populations should also account for these other processes. This study considered relationships between Pennsylvania sedge cover, management history, deer density and tree regeneration in a northern hardwood forest. All the factors considered had significant effects on saplings, but few significant relationships with tree seedlings. Stands managed using even-aged silvicultural systems had lower sapling densities for several species and species groups and lower species diversity than unharvested second-growth stands. High deer densities were associated with low levels of both sapling density and sapling species diversity. Pennsylvania sedge cover was negatively correlated with the density of secondary species and sapling species diversity in stands with moderate deer densities. Results from this study suggest a number of factors are influencing northern hardwood tree regeneration in these forests, and further research involving multifactor approaches is needed to clarify the mechanisms driving forest vegetation dynamics.