Litterfall nitrogen and phosphorous fluxes in two Tasmanian Eucalyptus nitens plantations

Knowledge of N and P fluxes in litterfall is essential to understanding N and P cycling in plantations. Rates of litterfall and N and P concentrations were measured for one year in two Eucalyptus nitens plantations of ages three and ten years. Measurements were in unfertilised treatments at both sites and in a fertilised treatment at the three-year-old site. Sampling positions within and between rows were compared in the younger plantation. For annual rates of litterfall and concentrations of N and P, leaves were ranked much greater than bark which was approximately equal to branches. Daily rates of litterfall and litter N and P fluxes were highest during February–March and lowest during September to November. Conversely, concentrations of N and P in leaf litter were highest during July to September and lowest during January to May. Annual litterfall and N and P fluxes were unaffected (P < 0.05) by fertiliser, sampling position or plantation age. However, fluxes in litterfall ranked higher in N-fertilised treatments than in unfertilised treatments and in within-row regions than in between-row regions of a three-year-old plantation. The average rate of litterfall was 5.1 Mg/ha/yr, the N flux was 52 kg/ha/yr, and