Form and structure of maple trees in urban environments

The form and structure of maple trees in an urban environment were measured and compared with the original design intent prepared 25 years previously. Bio-physical characteristics of the sites were also measured in an attempt to relate tree characteristics to environmental stress. Sugar maple (Acer saccharum) trees planted in turfed areas survived and were determined to possess a form and structure similar to expectations. However, most of the sugar maple trees that had been planted in a brick walkway had been replaced with Norway maple (Acer platanoides) trees, a species more adaptable to urban environments. Few of the original sugar maples in the walkway survived and their form, height, and diameter at breast height were not significantly different from those in turfed areas. However, the surviving walkway sugar maples had lower canopy densities, higher amounts of twig die-back, and smaller canopy widths. Overall these trees were more open-canopied and ragged in appearance than similar trees grown in turfed areas. Measurements of soil characteristics yielded inconclusive differences between the tree pits in bricked areas and those in grassed areas. Mapping and analysis of site characteristics identified microclimatic differences among the sites. Recommendations for application to landscape design and suggestions for future research have been identified.