ECO-PHYSIOLOGICAL RESPONSES OF TORTULA RURALIS UPON TRANSPLANTATION AROUND A POWER PLANT IN WEST HUNGARY

Abstract

  The moss Tortula ruralis was transplanted to six biomonitoring sites around the coal-fuelled power plant at Ajka (west Hungary), 27 November 1987-27 January 1988. After the period of exposure the amounts of Al, Cr, Fe, Ni and Pb in the transplants were distinctly elevated compared with the control. A clear gradient of decreasing contamination was visible from the spot nearest the power station towards the remote locations. The measured eco-physiological parameters did well correspond to this finding. While the photopigments (carotenoids + chlorophylls) amounted 2.14mg·g^-1 dry weight in the control, values of 0.78, 1.19 and 1.55 were detected for T. ruralis in the direct surroundings of the power plant. Net photosynthesis was reduced in all the transplants, ranging from -12% (Kislöd) to -48% (power station). Dark respiration was stimulated in five of the six transplants. Of particular interest were the changes in the resaturation responses. Mosses from the most polluted spots had significant lower rates of maximum dark respiration upon remoistening (“wetting burst”), and also reduced levels of net photosynthesis 24h within resaturation. The content of non-structural carbohydrates was decreased in all the transplants, apparently due to a much lower starch content. Thus, upon pollution starch is converted into soluble sugars to compensate the reduced production of photosynthates. It was concluded that eco-physiological parameters of T. ruralis are reliable to indicate environmental pollution, particularly those of photosynthesis and resaturation. By contrast, dark respiration responses proved to be doubtful for this purpose.