بررسي جمعيت شپشك سفيد راش و ارتباط آن با مشخصه هاي جنگل شناسي جنگلهاي راش شرقي ايران (مطالعه موردي: سري 5 صفارود، رامسر)

Investigation on Cryptococcus jagi (L.) population in relation to silvicultural characteristics of oriental beech forests (case study: Safaroud, Ramsar)

Cryptococcus /agi, the vector of Nectria sp., is one of the most important pests in beech forests which can cause beech bark disease. Because of its dispersion in the most beech forests of the northern Iran it should be taken under consideration. In this study , after forest survey, the infected area in watercatehment 30, districtf of SafarodlRamsar region were dist inguished and 123 infeeted individual trees have been demarcated. Some characteristics such as d.b.h, height, infection intensity, structure and forest type have been determined . Results showed that, the most infected trees were categorized in small timber, but the highest infection intensity was observed in large timber trees. Also the pest high abundance can be seen in the small timber with regular structure. On the other hand , the stands with Jess stem density have been appropriated for most infection. The pure beech stands were more infected compare to mix stands. The pest abundance rate was higher in north and north-west dire ctions . According to the results , although the disease symptoms are being observed, but no sever disease is recogn ized yet. As a matter of faet, it can be concluded that the pests are in their primary attack stage which could be controlled easily in this stage.