Responses of the Lichen Cladonia convoluta to High CO2 Level and Heavy Metal Treatment

Abstract

Despite of the downward acclimation of photosynthesis in C. convoluta, increased net photosynthesis and carbon balance can be anticipated in response to elevated atmospheric CO2 level. CO2 exchange measurement seems to be more indicative when detecting heavy metal stress than fluorescence parameters. Among these, the relative fluorescence decrease ratio (RFd690) shows damage first, suggesting that the primary attack site for heavy metal ions is CO2 fixation and reaction centres are harmed last. Long-term elevated CO2 ameliorates partly this damage by improving C-balance to a greater extent in the heavy-metal stressed lichens. © 1999, Verlag der Zeitschrift für Naturforschung. All rights reserved.