Preliminary study of manna oak (Quercus brantii Lindl.) tree decline in Dashte-Barm of Kazeroon, Fars provinc

To investigate the effect of recent oak decline, which covers a relatively vast area of Fars province, the oak forests of Dashte-Barm which were most exposed to drying was selected as the primary site to study. Firstly, base maps were provided. In initial forest surveys, the damaged as well as undisturbed sites were determined. 120 trees in affected area and 30 trees in non- affected area were randomly selected. The dried trees were categorized in for groups according to the drying percent. These classes were: %25, %25-%50, %50-%75, and more than %75. All factors including human factors (branch and/or clear cutting and prunning, rain-fed farming under the trees in the forest floor, etc.), climatic factors (rainfall and temperature), disturbing factors (pests and diseases) were assessed. Furthermore, quantitive and qualitative variables of high and coppice trees were separately recorded. Results showed that 58.3% of all dried and dead trees were coppice which consisted the most dead trees. The maximum numbers of dried and dead trees were those that were in their middle age, which are classified in 15-25 cm of diameter class. In term of drying percent, the maximum numbers of dried trees were in the fourth class (%75- %100).