EFFECTS OF SOIL ACIDIFICATION ON FOLIAR LEACHING AND RETRANSLOCATION OF METALS IN VASCULAR PLANTS

This paper reports on the seasonal patterns in leaf metal concentratio ns as influenced by artificial acidification and acidification due to acid precipitation at ambient levels in Southern Norway. The effects o f change in soil nutrient availability can be concealed for a long tim e because of ability of plants to retranslocate mobile nutrients inclu ding Cu, Mg, K, and Zn. Exceptions are, e.g., Ca and Mn which are rela tively immobile in the indigenous plant species studied. It appears fr om this work that long-term exposure to episodes of artificial rainfal l of pH 3.2, or to acid precipitation at ambient pH levels, may alter the seasonal patterns in tissue metal concentrations of vascular plant s. An enhanced retention of Mg and Zn in senescent leaves of deciduous species was observed. Foliar leaching of K on exposure to acid deposi tion may not be adequately compensated by root uptake.