Post-fire recolonization of dominant epiphytic lichen species on Quercus hypoleucoides (Fagaceae)

Following a forest fire (27 500 ha) in 1994, post-fire recolonization of Qu ercus hypoeleucoides by epiphytic lichens was documented as changes in lich en cover, number of small thalli, specific factors that affected reestablis hment of lichens, and modes of dispersal. Three sites in the Chiricahua Mou ntains (Arizona, USA) were chosen according to the severity of fire damage- unburned, moderately burned, and severely burned. From 1994 through 1997, t he amount of dead lichen cover significantly increased at the moderately bu rned site. For the same time period, the amount of live lichen cover signif icantly increased at the severely burned site. Numbers of new thalli increa sed significantly at the severely burned site each year but only in the las t year (1996-1997) for the moderately burned site. Bark texture and proximi ty to trees with lichens were among the most important physical factors for recolonization. The most important means of dispersal for Flavopunctelia p raesignis was fragmentation. For Punctelia hypoleucites, the primary means of dispersal was spores. Increases in live lichen cover and numbers of new thalli occur faster in severely burned areas probably due to the loss of li chens on tree trunks, which provides space and a lack of competition.