Site demands of Ulmus boissieri in Bazoft Tangehoonii Chahar Mahal -va- Bakhtyari province

In every part of the Zagros forests, some trees and shrubs were established, such as Quercus brantii , Pistacia sp. Acer cineracencs, Celtis australis , Platanus orientalis, Fraxinus sp, Ceracus mehleb, etc.With different composition Bazoft – Tangehooti,because of special site condition , presents a uniqu stand of elm(ulmus boissieri). This research was carried out to recognize the site demands of (Ulmus boissieri) statistical studies for qualitative and quantitative factor were conducted for each of plants completely. The systematic statistic network (40*40 meter)was used tomeasure trees growth and study of herbs and shrubbasead on 100 m plots. For investigation of regeneration condition , microplots (10m) were used in main plots. This stands was weak and seniority, so phyllophagous and stemborer pest were exited in the site severely. Investigation of trees growth showed that minium,maximum and average of diameter increment were1.5, 3.4 and 2.1 mm in year respectively.Volum increment of the stand  was 1.45 sylve per hectar.Dominant height of elmtrees was determined 1.54 m. Diameter distribution showed that this stand is more or less even age. Number of seedling for Ulmus boissieri and other trees species were estimated 7500 and 560 per hectar respectively. The suitable statistical model for relation between diameter and height of elm trees is calculated as: H=0.5147