نوع مقاله : مقاله پژوهشی
1 استادیار پژوهش، مؤسسه تحقیقات جنگلها و مراتع کشور، تهران، ایران
2 دانشگاه ایلام
3 دانشجوی دکتری جنگلداری، دانشکده منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ایران.
عنوان مقاله [English]
Recently, forest decline has outburst in Zagros forests, west of Iran. Consequently, we aimed considering dried trees and their spatial patterns as well as spatial structure at Bioreh forests in Ilam province, west of Iran. For this purpose, we selected and fully inventoried a 96 ha infected forest. The interested attributes were tree species, diameter at breast height (DBH), crown diameter, origin and number of sprout in coppice trees as well as Cartesian coordinates of dried trees with drying intensity more than 50 percent. For spatial point pattern analysis and spatial structure of interested attributes, O- ring statistics and variogram analysis were used, respectively. Results showed that the density of dried trees was 10 N/ha which more comprised of coppice trees, while high frequency percentage of drying was observed in large diameter classes. The spatial pattern of dried trees was determined as cluster up to 15 m, which implied that dried trees created patches with 4500 m2 surface area. No spatial structure were found for three interested attributes (DBH, crown diameter and number of sprout) which implied that there was no similarity among infected trees. These results can be used as an instruction to manage infected stands based on their spatial characteristics.