Investigating the oak trees with diffent dimentions contaminated by Loranthus europaeus in the middle Zagros (Case study: Gilan-e Gharb, Kermanshah)

Loranthus europaeus, a semi-parasite plant, is one of the main factors in depredating Zagros forests. It is distributed and grown by seed via birds. In order to study the oak infection induced by L. europaeus, the present study was conducted in the forest of Heydarbaighi village, Gilan-e Gharb, Kermanshah. For this purpose, 100 plots with 10 Ar area were applied based on systematic-random method in a 100*200 m survey network for 200 ha. The species type, DBH, tree height, crown diameters, and infectious rate induced by L. europaeus were measured based on DMR in three parts of tree crown. The results revealed that among nine tree species, Quercus brantii covered 77.5% of all trees. The results of ANOVA showed a significant effect of L. europaeus on classes of DBH, height, and crown area (P≤0.01). Duncan test confirmed the significant difference of infectious rate of L. europaeus in quantitative parameters. The infectious rate of L. europaeus increased by enhancing tree quantitative parameters such as DBH, height, and crown area. The highest infectious rate was observed in 45 and 50 cm DBH, 9 m height, and 15 m2 crown area. Our study suggests that the infected trees with high quantitative parameters should be first considered to control the L. europaeus than others.