Estimating urban trees growth, especially tree height is very important in urban landscape management. The aim of the study was to predict of tree height base on tree diameter. To achieve this goal, 921 trees from five species were measured in five areas of Mashhad city in 2014. The evaluated trees were ash tree (Fraxinus species), plane tree (Platanus hybrida), white mulberry (Morus alba), ailanthus tree (Ailanthus altissima) and false acacia tree (Robinia pseudoacacia). Regression analysis of tree height versus tree diameter revealed several models (linear, logarithmic, exponential and power) that could be used for estimating the tree height of these five species. The logarithmic, power and exponential functions provided a good fit to the data on tree height against tree diameter for ash tree (R2 = 0.9 and RMSE = 0.74), ailanthus tree (R2 = 0.92 and RMSE = 0.44) and plane tree (R2 = 0.72 and RMSE = 0.72), respectively.

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