Sugar maple (Acer saccharum) age structure reveals limited establishment and development of age cohorts in response to selection management in northern hardwood forests

• Published in: Forest ecology and management 2023-10, Vol.546, p.121356, Article 121356
• Main Authors: Henry, Catherine R., Walters, Michael B.
• Format: Article
• Language: English
• Subjects: Acer saccharum; Age structure; Northern hardwood forest; Sapling recruitment; Single-tree selection; Stocking
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/j.foreco.2023.121356

•Quantified sugar maple (SM) age structure in selection-managed northern hardwoods.•Most SM canopy trees in Michigan stands were 90–120 years old.•SM saplings 5 cm diameter at breast height (DBH) harvested winter 2017–2018. Our results offer little evidence to suggest that partial cuttings have promoted well-stocked ingrowth of sugar maple saplings. For most stands, age and diameter were non-linearly related, with a wide range of larger-diameter trees having similar ages. Among stands, sugar maple sawtimber (>24 cm DBH) averaged 106 years old and poletimber (11.4–24 cm DBH) 91 years, along with older than expected saplings (5–11.4 cm DBH) averaging 67 years. Most stands were dominated by a ∼100-year-old upper canopy cohort, with a majority having ≤2 younger cohorts typically of low density and >50 years old. Areas with greater snow water equivalent and lower January minimum temperatures, where deer populations have been historically low, generally have younger sugar maple saplings. Low density and generally old age of smaller size classes led to much lower stocking of age classes