Main content

Relationships between silviculture, lichen diversity and woodland caribou (Rangifer tarandus caribou) in northern Ontario

Show simple item record

dc.contributor.advisor Newmaster, Steven McMullin, Richard Troy 2012-01-11T20:40:55Z 2012-01-11T20:40:55Z 2011-12 2011-12-20 2011
dc.description.abstract The number of forest dwelling woodland caribou (Ranger tarandus caribou) in Ontario is declining. One of the reasons believed to be causing this decline is a reduction in critical habitat due to harvesting and post-harvest management practices. Critical habitat for woodland caribou includes a large amount of lichen biomass, which is their primary winter forage. In this study, the environmental variables that are most important for explaining lichen diversity are determined and the influence that silvicultural practices have on these variables is assessed. A method for estimating lichen biomass at the stand level was developed so comparisons could be made between forest stands and different silvicultural practices. This method requires the identification of individual lichen species. Therefore, a key and species descriptions are provided for all the fruticose lichen species in Ontario, which is the form of all the species that occurred with a high biomass in the stands assessed. Using these tools and the method developed for estimating lichen biomass, the lichen richness and biomass in forest stands across northern Ontario were examined and compared. The variables that were most important for explaining lichen richness were the number of microhabitats, the variation in the amount of light coming through the canopy and the stand age. For lichen biomass, the most important explanatory variables were the total amount of light coming through the canopy, stand age and sandy soil. Silvicultural treatments were found to have an effect on lichen diversity in the short-term (1 yr) and the long term (25-40 yrs). Lichens exhibited different tolerances to herbicides ranging from no effect to 100% mortality one year post-treatment. The long-term effects of herbicides and planting were found to alter lichen communities. Stands with herbicide treatments also had less lichen biomass than the rest of the stands examined. The creation or conservation of mature forest stands on sandy soil with low canopy closure and high structural complexity should help preserve lichen richness and biomass in the eastern boreal forests of North America. If lichen diversity is not managed, consequences may include an increase in soil erosion, altered nutrient exchanges, or a decline in the organisms that rely on lichens, such as the woodland caribou. en_US
dc.description.sponsorship Funding for this study was provided by the Natural Sciences and Engineering Research Council of Canada, the Canadian Foundation for Innovation, the Ontario Ministry of Natural Resources’ Vegetation Management Alternatives Program, and the Forest Ecosystem Science Co-operative Inc. en_US
dc.language.iso en en_US
dc.rights.uri *
dc.subject Lichen en_US
dc.subject structural complexity en_US
dc.subject silviculture en_US
dc.subject sustainable forest management en_US
dc.subject woodland caribou habitat en_US
dc.title Relationships between silviculture, lichen diversity and woodland caribou (Rangifer tarandus caribou) in northern Ontario en_US
dc.type Thesis en_US Integrative Biology en_US Doctor of Philosophy en_US Department of Integrative Biology en_US
dc.rights.license All items in the Atrium are protected by copyright with all rights reserved unless otherwise indicated.

Files in this item

Files Size Format View Description
richardTroyMcMullin_phdThesis.pdf 41.89Mb PDF View/Open PhD Thesis_R.T.McMullin_Dec.23, 2011

This item appears in the following Collection(s)

Show simple item record Except where otherwise noted, this item's license is described as