Current issue: 54(2)
The ultrastructure of Hypogymnia physodes (L.) Nyl. and Alectoria capillaris (Bryoria capillaris (Ach.) Brodo & D. Hawksw.) grown or transplanted near a fertilizer plant and a pulp mill was compared to normal ultrastructure of these lichen species. The ultrastructural changes observed were highly similar in the symbionts of both species and near both the factories although the emissions are different. In the lichens grown near the factories the number of algae had clearly increased. The appearance of the chloroplasts was roundish compared to controls. The pyrenoglobuli and cytoplasmic storage bodies were smaller than normally and the number of polyphosphate bodies had increased. Also, in mycobionts storage droplets were very small or absent and many vacuoles and dark inclusions appeared to hyphae in contrast to controls. In transplanted lichen there existed mainly the same ultrastructural changes as in the lichen grown near factories. Near the fertilizer plant the damage was, however, more severe because all the lichens died during 6–7 months after transplantation. Near the pulp mill part of the lichens survived and seemed to adapt to air pollution.
Air-borne Cu and Zn from a brass foundry at Gusum, SE Sweden, have considerably disturbed the lichen and bryophyte vegetation in the coniferous forest environment. The occurrence of lichens on Norway spruce twigs decreased rapidly with increasing Cu concentrations in Hypogymnia physodes above 90 ppm (background value 10–15). The epiphytic vegetation is reduced within 2–3 km from the foundry. Only stunted individuals occur in the close vicinity of the pollution source.
The cover of one of the quantitatively most important mosses, Hylocomnium splendens, is greatly reduced by the heavy-metal deposition. Cover values of 20–50% are not uncommon in distant sites (Cu concentration 15–35 ppm). There is a significant negative correlation between Cu concentration in the moss and its cover. The moss cannot survive much more than ca. 130 ppm Cu (and 360 ppm Zn). Live individuals are no more found within 1.5 km from the foundry.