Spatial variation and dispersion pattern of European yellow mistletoe (Loranthus europaeus) affected forests in Zagros area, a case study of Ilam forests

Yellow mistletoe (Loranthus europaeus) species is a semi-parasitic plant presently threatening Zagros forests. Spatial variation and dispersion pattern of this semi-parasitic plant is important for its control and management in this area. For this purpose, a 37 ha forest patch forests was selected in Ilam province and 541 individual trees in 27 transects of 320m were examined for plant species and yellow mistletoe severity and abundance. To investigate spatial variation and mapping of forest infection, variogram analysis and Kriging and IDW interpolation methods were applied. Results showed that 78% of individual trees were infected by yellow mistletoe and its distribution had strong spatial structure (89%) and a hotspot by 206 m range of influence. Both IDW and Kriging showed acceptable variance error for mapping. Kriging method is considered to be a valid method for interpolation and mapping of yellow mistletoe affected areas. Appropriate distance for transect sampling was estimated as 137 m based on variogram analysis.