Accession and cycling of elements in a coastal stand ofPinus radiata D. Don in New Zealand

Summary The accession and cycling of elements in a 14-year-old coastal stand ofPinus radiata D. Don was measured for one year. The element contents (mg m^–2 year^–1) of bulk precipitation and throughfall respectively were: NO₃–N 41, 12; NH₄–N 133, 154; organic-N 157, 396; Na 4420, 9700; K 387, 2900; Ca 351, 701; Mg 486, 1320. Of the increase in element content of rainwater beneath the forest canopy 20% (NH₄–N), 70% (organic-N), 3% (Na), 90% (K), 20% (Ca) and 30% (Mg) was attributed to leaching; the remainder to washing of aerosols filtered from the atmosphere by the vegetation. The canopy absorbed approximately 40 mg m^–2 year^–1 of NO₃–N. Litterfall was the major pathway for the above-ground biogeochemical cycle of N (93%), Ca (96%) and Mg (74%), and leaching was the major (73%) pathway for K.