Introduction of Two Methods for Determining Mistletoe Infection Intensity and Their Comparison in Noor Forest Park


The damages due to Dwarf Mistletoes to the industrial forests encouraged the scientists to evaluate the infection intensity and illustrate the spatial distribution of mistletoes for forest management, wild life and biodiversity conservation. There are two current systems to evaluate infection intensity wich are easier, cheaper, more efficient and authoritative than others in all over the world, namely DMR and BVR. For investigation on mistletoe infection in Noor Forest Park and comparison of these two procedures, 30 sample plots with an area of 0.1 ha were selected. Since 94% of infected individuals in plots were Iron Wood trees (Parrotia persica), therefore only Iron Wood trees were evaluated. In total, 243 trees of 329 infected Iron Woods were selected randomly and analyzed. Results showed that 67% of trees had similar rate with these two systems and 31% had more DMR. Totally, the implementation procedures of DMR and accuracy of evaluation seemed better than BVR. Therefore DMR system can be used in studies of stands with high rate infection to determine the impact of mistletoe on forest ecosystem, stand structure, forest growth and production and even effect on infected individual productivity. Moreover, the results of infection survey in three parts of the crown showed that infection intensity on upper part of trees was more than the middle and lower parts respectively, which is because of the relationship of mistletoe seed dispersal to sitting, nesting and roosting sites of the birds that eating mistletoe berries.