Abstract

Our research shows that the average dbh has increased significantly over the years. As trees die or are removed for being hazards, they are not being replaced. Therefore, there are fewer trees in the urban forest. The dbh (diameter at breast height, about 1.5 meters) was measured and the trees were placed into size classes: (1) 5.08 to 10.16 cm. (2 to 4 inches), (2) 10.16 to 25.40 cm. (4 to 10 inches), (3) 25.40 to 40.64 cm. (10 to 16 inches), and (4) greater than 40.64 cm. (16 inches). Between 1980 and 2005, our research shows that there was a 51% loss of the small trees in the urban forest, both public and private trees. Many of the original trees are still there. They have grown and are larger. When we compare the percentage of small trees in the urban forest in 1980 (59%) to the percentage of small trees in 2005 (25%), the urban forest has a loss of 34% of small trees. The conclusion is that urban trees die or are hazards no matter what size they are. For sustainability, we need to be replacing them, and these replacements are small trees.