The relative incidence of mistletoes found in pinyon-juniper woodlands is estimated for the Coconino National Forest, Arizona, using a roadside survey. Approximately 50% of the pinyon-juniper woodlands surveyed were infested with juniper mistletoes (Phoradendron juniperinum or P. capitellatum). In contrast, only about 12% of the areas surveyed were infested with pinyon dwarf mistletoe (Arceuthobium divaricatum). In these infested woodlands, 70% with juniper mistletoes and 44% with pinyon dwarf mistletoe were lightly infested. Most areas where pinyon dwarf mistletoe populations were observed (90%) also had juniper mistletoe (P. juniperinum) present, but many juniper mistletoe populations observed had no pinyon dwarf mistletoe (50%), although pinyon pine was common at those locations. Therefore, pinyon dwarf mistletoe is frequently co-distributed with juniper mistletoe as has been suggested by other investigators, but juniper mistletoe frequently occurs where there is no pinyon dwarf mistletoe present.
Daugherty, Carolyn M. and Mathiasen, Robert L.
"Estimates of the incidence of mistletoes in pinyon-juniper woodlands of the Coconino National Forest, Arizona,"
Western North American Naturalist: Vol. 63
, Article 13.
Available at: http://scholarsarchive.byu.edu/wnan/vol63/iss3/13