Lichen 40 and 24

These lichens are extremely slow growing and their lifespan is unknown. A long-term study is underway to photographically document a group of marked lichens at this site. Photogrammetry is being used to generate quantitative data to describe rates of establishment, growth, dieback, mortality and succession. The hope is that this information may lead to improvements in the lichenometric dating method. Lichenometric dating has often used spurious assumptions about lichen growth and ecology to “indirectly calibrate” growth rates that can be used to estimate the size-age of lichen colonized surfaces. If you wish to assist in this research, please contact D. P. McCarthy at the Dept. of Earth Sciences, Brock University, St. Catharines ON. Canada.Repeated photographs of Rhizocarpon geographicum agg. lichens #40 and 24 on quartzite rocks at the Illecillewaet Glacier, BC, Canada show changes that occurred between 1996 and 2014