Distribution and influencing factors of mistletoe in Lidui Park, Dujiangyan, Sichuan

Due to the importance of Ornamental trees in urban ecosystems, it is crucial to understand the distribution, prevalence, and intensity of parasitic mistletoe (Loranthaceae and Viscum spp.) infection across urban landscapes. A survey conducted in Lidui Park, Dujiangyan, Sichuan, revealed that out of 1,362 woody plants, 171 individuals from 30 species, 30 genera, and 21 families served as host plants for mistletoe, resulting in an overall parasitism rate of 12.8%. A total of 490 mistletoe clusters were recorded, with an average infestation intensity of 2.8 clusters per host. Mistletoe was predominantly found in open areas near water bodies and low-rise buildings. The tree species with the highest parasitism rates and host preferences were Pyrus betulaefolia, Gleditsia sinensis, Broussonetia papyrifera, Salix babylonica, Pterocarya stenoptera, and Metasequoia glyptostroboides. Five variables (deciduous, height, DBH, adjacent to water body, adjacent to building construction) were positively correlated with the parasitism rate. One variable (providing food for birds known to spread mistletoe seeds) was negatively correlated with the parasitism rate. Another three variables (height, deciduous trees,providing food for birds known to spread mistletoe seeds) had a significant positive impact on the parasitism intensity of mistletoe. We recommend targeted removal of mistletoe from vulnerable ancient trees in Lidui Park and conduct further research on the impact of mistletoe to maintain the biodiversity of Lidui Park.