Comparing structural attributes in uneven-aged managed and unmanaged sugar maple stands

We used 11 silvicultural trials in forests dominated by sugar maple (Acer saccharum Marsh.) to compare the development of structural attributes between unmanaged stands and stands subjected to two selection cuttings. Results showed that managed stands had significantly lower amounts of large live and dead trees, lower downed coarse woody debris (CWD) volume and lower density of large trees with wildlife cavities compared to unmanaged stands. Despite these differences, both managed and unmanaged stands had sufficient amounts of large trees and large trees with wildlife cavities to maintain excavator bird habitat based on minimum target guidelines from the literature. In both managed and unmanaged stands, minimum target guidelines to emulate old-growth conditions were not met: at least 30 live trees ha⁻¹ >49.0 cm in diameter at breast height, and at least 11 m³ ha⁻¹ of downed CWD volume with large-end diameter >44.0 cm. We discuss management options to promote the development of structural attributes in managed, uneven-aged sugar maple stands.