title: Lichen conservation in heavily managed boreal forests.
abstract: Lichens are an important component of the boreal forest, where they are long lived, tend to accumulate in older stands, and are a major food source for the threatened woodland caribou (Rangifer tarandus caribou). To be fully sustainable, silvicultural practices in the boreal forest must include the conservation of ecological integrity. Dominant forest management practices, however, have short-term negative effects on lichen diversity, particularly the application of herbicides. To better understand the long-term effects of forest management, we examined lichen regeneration in 35 mixed black spruce (Picea mariana) and jack pine (Pinus banksiana) forest stands across northern Ontario to determine recovery following logging and postharvest silvicultural practices. Our forest stands were 25-40 years old and had undergone 3 common sivilcultural treatments that included harvested and planted; harvested, planted, and treated with N-[phosphonomethyl] glycine (glyphosate); and harvested, planted, and treated with 2,4-dichlorophenoxyacetic acid (2,4-D). Forest stands with herbicide treatments had lower lichen biomass and higher beta and gamma diversity than planted stands that were not treated chemically or control stands. In northwestern Ontario, planted stands that were not treated chemically had significantly greater (p < 0.05) alpha diversity than stands treated with herbicides or control stands. Our results show that common silvicultural practices do not emulate natural disturbances caused by wildfires in the boreal forest for the lichen community. We suggest a reduction in the amount of chemical application be considered in areas where lichen biomass is likely to be high and where the recovery of woodland caribou is an objective.
authors.affiliation: Department of Integrative Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada. rmcmulli@uoguelph.ca.
authors.forename: Richard Troy
authors.initials: RT
authors.lastname: McMullin
authors.forename: Ian D
authors.initials: ID
authors.lastname: Thompson
authors.forename: Steven G
authors.initials: SG
authors.lastname: Newmaster
mesh_terms: D000818:Animals; D044822:Biodiversity; D003247:Conservation of Natural Resources; D016468:Forestry; D008011:Lichens / Q000502:physiology*; D015999:Multivariate Analysis; D009864:Ontario; D011157:Population Dynamics; D012053:Reindeer / Q000502:physiology; D014197:Trees
keywords: 2; 4-D; caribú; community structure; diversidad de líquenes; ecological integrity; estructura de la comunidad; estructura del bosque; forest structure; glifosfato; glyphosate; integridad ecológica; lichen diversity; silvicultura sustentable; sustainable silviculture; woodland caribou