Evaluating the lack of growing space, stability and quality of Eldar pine and Field elm in Yazd University green space

Proper designing of green space in educational centers increases vitality and ensures the safety of users and reduces costs. The purpose of this study was to estimate the lack of root and canopy growth space of the most important green space trees of Yazd University. At first 124 pine and 102 elm trees were randomly selected in different parts of the University and their morphological characteristics were measured. The height/diameter coefficient was used to determine the susceptibility to wind-throw. To determine the shortage of canopy growth space, the canopy area of ​​5% of the largest trees and to calculate the shortage of root growth space, the British standard were used. Then, classification of frequencies was done. Results showed that the mean height coefficient of pine and elm were 56.85 and 51.21 respectively. About 87.1% of the pines and 42.2% of the elms were in a stable condition. About 96% of the elm trees and 94.4% of the pine trees had insufficient planting distance and therefore, do not have enough space to reach the maximum dimensions of the crown. According to the results, 77% of pines and 54% of elm trees lacked root growth space. Tomographic examination via ultrasonic technology showed decay only in some broken trees. Based on the results, it is recommended to assign enough space for the growth of canopies and roots in order to reduce the possibility of uprooting, before designing the planting areas and building curbs and sidewalks.