DIVERSITY AND SIMILARITY OF LICHEN FLORAS OF COUNTRIES ALONG A SOUTH-NORTH GRADIENT FROM ITALY TO GREENLAND

Abstract

Species diversities and similarities of lichen floras from Italy via Austria, Germany, Denmark, Finland, Sweden and Norway to Greenland are compared for the complete floras and separately for bark, wood, rock and soil, the latter two also for acidic and calcareous. Lichen species diversity declines about 15% from Italy to Norway but 50% from Italy to Greenland, a much lower percentage than for vascular plants (92%!). The Sørensen coefficient and an NMDS-ordination display geographic groups well: Italy, Austria and Germany, Finland, Sweden and Norway and finally Greenland. Denmark as the only country without mountains lacks saxicolous species and differs from the other countries. About half of the lichen species grow on rock, followed by bark, except for Greenland, there soil. Diversity and composition of lichen floras on bark and wood are rather homogeneous from Italy to Scandinavia, on soil even from Italy to Greenland. Diversity is higher on acidic than calcareous rock and soil, a contrast to observations from vascular plants. The diversity loss in “southern” calciphytic species in the northern countries is compensated by additional “nordic” species on acidic substrate. From Greenland even more acidophytic terricolous lichen species are known than from Italy. The reasons for the pH dependent diversity patterns are, same as for vascular plants, not known.