| Proper selection of tree size is essential to maximize the efficiency of canopy restoration efforts. Municipal and landscape ordinances often specify the use of large caliper trees, 7.6 cm (2.5 in) or larger, to provide a more substantial impact. However, the costs associated with transplanting larger caliper trees can have a negative impact on planting budgets resulting in fewer trees planted on a site. In this project three hundred trees of five different stock sizes 4.4 cm (1.75 in), 5.1 cm (2 in), 6.4 cm (2.5 in), and 7.6 cm (3 in) balled-and-burlapped, and 4.4 cm (1.75 in) bare-root stock were planted in four Michigan communities. Our objectives were to: (1) Quantify the influence of stock size on growth, canopy development, and physiological function during establishment, (2) Characterize the relationship between soil and environmental factors on growth and tree physiology in the urban environment, (3) Provide recommendations to municipal arborist to increase the efficiency of canopy restoration programs through proper size selection. Our study quantified the differences in growth, canopy development, and physiology of Autumn Blaze maple (Acer x freemanii 'Autumn Blaze'), swamp white oak (Quercus bicolor), and Bloodgood London plane tree (Platanus x acerfolia 'Bloodgood'). During the first two years of establishment, significant differences in the rate of canopy development, trunk growth, and shoot elongation suggest that smaller trees establish at a faster rate than large trees in the urban environment. However, the relationship between stock size and gas exchange was not significant. |
