Lichen communities in two old-growth pine (Pinus) forests

Abstract

AbstractMany lichen species have specific environmental requirements for colonization. Old-growth forests contain microhabitats required by a particular suite of lichens. In Ontario, Canada, old-growth forests are increasingly uncommon and the lichen communities within some of these forests are not well known. To better understand the lichen communities that inhabit old-growth forests in the province, we examined the lichen biota on coarse woody debris (CWD) and trees in a red pine (Pinus resinosa) and a white pine (Pinus strobus) dominated stand in northern Ontario. Lichen diversity was assessed on different forms of CWD and trees in each forest. Lichen diversity did not differ significantly between CWD types in the red pine forest, but was significantly different in the white pine forest. There was no significant difference in lichen diversity amongst different decay stages of CWD in either forest. In both forests, lichen communities on stumps, logs, and snags differed from lichen communities present on trees. A variety of CWD types is important for overall lichen species richness in the red pine forest. Our results demonstrate to land managers that different types of old-growth forests are ecologically unique, even those dominated by tree species in the same genus. Management of an old-growth forest should suit its individual ecology.