Effects of soil acidification on foliar leaching and retranslocation of metals in vascular plants

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