A new methodological approach to evaluation of mechanical resistance of green plantings in urban environments

The trees growing in urban environments are exposed to the highest pressure of negative exogenous factors and, consequently, many tree species come to the critical age and become hazardous. A complex approach to evaluate the condition of green plantings under the technogenous load using visual, instrumental, biomechanical etc. methods allows timely and reliable identification of hazardous trees. For this purpose, we developed a new methodology of determining the hazardous degree of trees in residential areas. This method is based on the accounts of tree mechanical hardiness evaluation and up-to-date instrumental research data to be used by municipal services employed in plantings monitoring and care. The main parameters are: age, diameter of the base, diameter at height, trunk girth at the base, trunk girth at a height of 1,3 m, the height of the tree, the angle of inclination of the trunk, the vital status score for Saveleva, morphological damage to the trunk, the description of the crown architectonics, the presence of morphogenetic and exogenous damage to the leaf blade, the population of the trunk pests, the presence of hollows, the wind feature and the loading of this site, the mode of visiting the territory (recreational load), the direction of possible fall, percentage of sound rot, modulus of elasticity of wood, density of wood, the ratio of biomass to critical mass, mechanical resistance to static and dynamic loads according to calculations on biomechanics. In the case study of a model tree (London plane) the applicability of this approach to landscaping practices is shown.