Forest Co-op Lichens & Caribou VMAP Project
The third and final field season was completed during the summer of 2010 resulting in a complete data set for analyzing the explanatory variables of lichen community structure in boreal forests of Ontario. A new technique for measuring lichen biomass has been fully developed and tested. It is based on mathematical calculations of known factors that contribute to biomass for specific species of lichens and can be used to estimate lichen biomass using abundance data. The science team has used this method to elucidate cryptic patterns in lichen community structure. For example Cladonia stygia, often confused with C. rangiferina, is a species that is uncommon in the literature, but has the highest biomass of any lichen species across the landscape of northeastern Ontario. Four lichen genera grow with enough biomass to serve as forage for woodland caribou in the winter. The arboreal genera include Bryoria (eight species), Evernia (one species, E. mesomorpha), and Usnea (eight species). The terrestrial species all belong to the genus Cladonia, (six species) of which most belong to the subgenus Cladina, which are known as the reindeer lichens. Preliminary results indicate that lichen dominated stands have low tree stem density, because lichens require exposure to light. The lichen biomass in these stands can range between 7,000 and 10,000 kg/ha, which, in some cases, can be comparable to the biomass of the low density trees more biomass in lichens than trees! A positive relationship was found between lichen diversity and both stand age and canopy closure.