Spatial variability of forest infection with Yellow Mistletoe (Loranthus europaeus) in Zagros forests of Iran using IDW and Kriging methods

Abstract

Abstract. Yellow Mistletoe (Loranthus europaeus) is one of the impacting pathogens in the Zagros forests of Iran. Spatial variability and mapping of this agent are important for its control and management. For this purpose, a forest patch of 37 ha in the Ilam province of Iran was selected, and 541 individual trees in 27 transects for species, severity and density of infections with Yellow Mistletoe as well as Cartesian coordinates were considered. To investigate the spatial variability and mapping of forest infection, Kriging and IDW (Inverse Distance Weighting) interpolation methods were used. Results showed that 78% of individual trees are infected with Yellow Mistletoe and that its distribution has a strong spatial structure (89%) as well as a hotspot of 206 m range of influence. Appropriate distance for transect sampling was determined to be 137 m, based on a variogram analysis. Both IDW and Kriging showed acceptable variance error for mapping. However, Kriging shows some advantages and thus seems to be more recommendable for the interpolation and mapping of Yellow Mistletoe infection in this region.