The Arboretum at the University of Guelph, Ontario: An urban refuge for lichen biodiversity

Abstract

Southern Ontario is the most densely populated region in Canada and urbanization is extensive. As a result, a large number of natural areas have been set aside in the cities, such as parks and conservation areas. The value of these areas for conserving lichen biodiversity has not been investigated in Ontario. Therefore, between 2008 and 2014, we systematically examined the lichens and allied fungi in the Arboretum at the University of Guelph, a 165 hectare park and nature reserve centrally located in the City of Guelph, Ontario. One hundred and four species in 55 genera were recorded and several are considered rare. Caloplaca soralifera is recorded for the first time in Canada. Provincially, Acarospora moenium is recorded for the second time, Bacidina egenula and Strangospora moriformis are reported for the third time, and Evernia prunastri was collected for the second time in southern Ontario in over a century. An undescribed species of Chaenotheca with distinctive brown-orange pruina on the capitulum and mazaedium was also discovered along with nine species that have a provincial status rank of S1 (critically imperilled), S2 (imperilled), or S3 (vulnerable). The native old-growth forests contained the greatest number of lichen species, particularly the largest one, which borders the wetland in the Nature Reserve. Investigations for lichens throughout Guelph revealed two species that were not found in the Arboretum. However, a substantial number of species were discovered in the park that were not found anywhere else in the city. Our results show that the Arboretum is a refuge for many lichen species within this urban landscape.