Nutrient Concentrations in Foliage of Species Within a New South Wales Sub-Tropical Rainforest

Abstract

Sub-tropical rainforests in New South Wales are complex, often with more than 30 tree species ha−1. Estimation of nutrient contents involves obtaining information on the range of nutrient concentrations both in different species and in different forest strata. The foliage from the tree and shrub components of an undisturbed forest were analyzed chemically together with the small tree and shrub component of an area logged two years previously. The site had high nutrient availability. All nutrients analyzed (nitrogen, phosphorus, calcium, magnesium, potassium, manganese, aluminium, sodium, zinc, iron, boron and chloride) varied between species. Some individuals accumulated high concentrations of specific nutrients, but an accumulator of one nutrient was not necessarily an accumulator of any other. Assessment of nutrient concentrations on the basis of forest strata showed major differences. Nutrients were accumulated in higher concentrations on a disturbed site than on an undisturbed site. This has been discussed in relation to nutrient conservation mechanisms after disturbance. Within the undisturbed stand, the large shrub stratum had the highest concentrations of nitrogen, phosphorus, potassium and boron. Mean concentrations of aluminium, sodium and chloride were highest in the small shrub stratum, mainly because several species accumulate these elements.