Effect of nitrogen supply on nutrients in litter fall and crown leaching in a stand of Corsican pine.
Nitrogen fertilizer applied over three years to Corsican pine in Moray Forest increased the weight of needle fall, increased the levels of nitrogen and potassium in needle-litter and decreased the levels of phosphorus, calcium and magnesium. Litter fall accounted for nearly all the nitrogen and phosphorus released by the trees. Rainwater gained considerable quantities of potassium, calcium, magnesium and sodium on passing through the canopy but only 30-60% of this gain was derived from crown leaching, the remainder being washed-down aerosols. Crown leaching represented 89% of the sodium, 48% of the magnesium, 44% of the potassium and 8% of the calcium released by the trees. Only the leaching of potassium was affected by nitrogen fertilizer. Variations in the annual and seasonal patterns of nutrient release are discussed.