Height Development of Upper-Canopy Trees Within Even-Aged Adirondack Northern Hardwood Stands

Abstract Knowledge of the relative rates of height growth among species is necessary for predicting developmental patterns in even-aged northern hardwood stands. To quantify these relationships, we used stem analysis to reconstruct early height growth patterns of dominant and codominant sugar maple (Acer saccharum Marsh.), yellow birch (Betula alleghaniensis Britton), white ash (Fraxinus americana L.), and America beech (Fagus grandifolia Ehrh.) trees. We used three stands (aged 19, 24, and 29 years) established by shelterwood method cutting preceded by an understory herbicide treatment. We analyzed 10 trees of each species per stand. Height growth was similar across stands, allowing us to develop a single equation for each species. Our data show that yellow birch had the most rapid height growth up to approximately age 10. Both sugar maple and white ash grew more rapidly than yellow birch beyond that point. Beech consistently grew the slowest. White ash had a linear rate of height growth over the 29-year period, while the other species declined in their growth rates. By age 29, the heights of main canopy trees ranged from 38 ft for beech to 51 ft for white ash. Both yellow birch and sugar maple averaged 46 ft tall at that time. By age 29, the base of the live crown had reached 17, 20, 21, and 26 ft for beech, sugar maple, yellow birch, and white ash, respectively. Live–crown ratios of upper-canopy trees did not differ appreciably among species and remained at approximately 40% for the ages evaluated. These results suggest that eliminating advance regeneration changes the outcome of competition to favor species other than beech. North. J. Appl. For. 21(3):117–122.