Mistletoe infection of trees located at fragmented forest edges in the cloud forests of Central Veracruz, Mexico

Abstract

We investigated the Psittacanthus schiedeanus mistletoe infection of its preferred host tree species Liquidambar styraciflua in remnants of cloud forest in Central Veracruz, Mexico. We studied whether or not the location of host trees on forest fragment edges has a direct effect on mistletoe infection, and explored among host tree variation in intensity of infection. In four 1 ha plots, we marked 200 L. styraciflua and recorded height, diameter at breast height (DBH), distance to fragment edge, distance to conspecific tree, and number of mistletoe adult plants per tree, or canopy area (upper or medium-low). Overall, tree densities varied among plots, but not the number of infected or non-infected L. styraciflua trees. Fifty-nine percent (118/200) of the L. styraciflua trees were infected. They were similar in the number of P. schiedeanus plants per tree, but not in height, DBH, or distance to conspecifics. The most severely infected trees were tall, located on fragment edges, and located near an infected conspecific. Trees located on fragment edges had more mistletoe plants per tree and medium-low area of the tree. Also individual tree features as height and distance to conspecific affected, but not DBH. We suggest that individual differences among host trees play an important role in explaining local abundance and distribution of mistletoe plants. Inside forest fragments, tree density of Liquidambar, and edges lengths are important factors in determining the presence and intensity of P. schiedeanus infection.