Development of stand density management diagram for Quercus brantii even-aged coppice stands in the Central Zagros

Stand density management diagram is one of the effective methods for designing, displaying and evaluating various density regime management options in the even-aged stand. The aim of this study was to determine the tools for density management in Quercus brantii even-aged stands. This diagram can be used to manage stand density and estimate the stand volume quickly. For the development of this diagram, four variables were used including dominant heights, number of tree per hectare, quadratic mean diameter and volume per hectare. Data were collected from 15 even-aged stands in 71 plots in the central Zagros located in Charmahal Va Bakhtiari province, Iran. The construction of this diagram was carried out with two equations of the volume and quadratic mean diameter with the dependent variables of the number of tree per hectares and the dominant height. Because of the error in the estimation of left and right sides of the diagram, simultaneous fitting was used. Among different indices of density, relative density index due to its independence on site quality and age of the stand as well as dominant heights as a criterion for determining the interval thinning were used for determining the growth status in this diagram. Finally, in order to clarify the application of this diagram, a practical example of the thinning schedule with a dominant height of 8 m and two thinning intervals was proposed for a stand with medium stocking volume. This diagram can be used for rapid estimation of the volume and to suggest thinning schedules in coppice management planning of Quercus brantii stands.