Fig. 4.

Usnea antarctica deterioration inside OTCs on Signy Island. a The picture of 2003 shows the cover of U. antarctica on a boulder inside an OTC. The picture from 2006 shows the same boulder with an obviously lower lichen cover 3 years later. The distance between the metal pins on the right hand side of each picture is 30 cm. b Chlorophyll content (a and b) of U. antarctica in control plots and OTCs during the summer of 2006. Bars are means of n = 5, *Significant (P < 0.01) difference in chlorophyll (a and b) content between control plots and OTCs