Epilithic lichen communities in High Arctic Greenland: Physical, environmental, and geological aspects of their ecology in Inglefield Land (78°–79°N)

The present investigation of High Arctic epilithic lichens and their substrate is based on field observations in Inglefield Land, North-West Greenland, mainly in 1999, with subsidiary observations from 1995. Eighteen rock samples, all glacial erratics, were specifically selected on the basis of macroscopic mineralization features such as iron and copper staining, vein and breccia structures, and ore minerals. The samples are representative of the crystalline shield, and their lithologies can be matched with exposures in Inglefield Land. Seven lichen communities are recognized, viz. Pleopsidium chlorophanum c., Xanthoria elegans var. splendens c., Dimelaena oreina–Physcia caesia–Xanthoria elegans c., Xanthoria elegans–Umbilicaria virginis c., Orphniospora moriopsis c., Porpidia flavicunda c., and Tremolecia atrata c. The studied material on the 18 samples reveals no conspicuous correlation between metal concentrations in the rock samples and the lichen communities and, broadly speaking, it can be stated that the lichens reflect more the properties of the rock surface, such as, for example, nitrogen- and iron-bearing weathering crusts, than the mineralogical composition of the rocks. However, there is a very close affinity between the Orphniospora moriopsis community and one variety of syenitic rocks with elevated magnetite and phosphorus.