Nutrient returns in litterfall in two indigenous and two radiata pine forests, Westland, New Zealand

Abstract

Abstract Mean annual fluxes over a two-year period ofNa, K, Ca, Mg, P, Cl, S, and N in foliage, wood, and total litterfall were measured in a podocarp-hardwood, a hard beech (Nothofagus truncata), and two Pinus radiata (aged 9–10 years and 18–19 years) forests. Maximum monthly foliage litterfall occurred on the podocarp-hardwood plot during summer, and on the hard beech and 18–19 year-old radiata pine plots during spring and early winter. Seasonal cycles were observed for Cl and P concentrations in total litterfall at all plots; P concentration in foliage litterfaU on the 18–19 yearold radiata pine and hard beech plots. and in wood litterfall on the hard beech plot; and K concentrations in the 18–19 year-old radiata pine plot. Potassium and, to a lesser extent, P and Mg were removed relatively rapidly from senescing leaves either before or soon after abscission. Calcium levels were higher in foliage litterfall than in intact foliage.