Artificial tip-up mounds influence tree seedling composition in a managed northern hardwood forest

Abstract

Silvicultural regeneration methods focus on manipulating the forest canopy, but success can depend on the use of site preparation to control competing vegetation, including the density of advance regeneration, and create suitable microsite conditions for germination and seedling establishment. Tip-up mounds are known to provide favorable conditions for some tree species, but the creation of tip-up mounds as a method of site preparation has scarcely been investigated. We assessed effects of artificial tip-up mounds on tree seedling composition across a gradient of regeneration methods and residual overstory densities 2–4 years post-implementation. We found that tree seedling communities on mounds in some treatments were compositionally distinct from untreated reference plots. However, no tree species exhibited a strong affinity for mounds when analyzed independently from the regeneration method, and much of the difference in composition was associated with lower dominance of maples ( Acer spp. L.) on mounds. As maples are strong competitors in forests regenerated with selection systems, reduced maple competition on artificial mounds could advantage desired under-represented species and aid in natural regeneration over time. Therefore, in stands where promoting tree species diversity is desirable, implementing artificial tip-up mounds as part of a long-term strategy may be beneficial.