Research Branch Report No. 181

Biomass and nutrient distribution in radiata pine.  H. T. L. Stewart, D. W. Flinn and J. M. James.  September 1981.  14 pp.  (unpubl.)

SUMMARY

Information on the quantities of nutrients in the above-ground biomass of radiata pine stands is essential if the effects of harvesting on nutrient removal are to be determined. If information is also available on the quantities of nutrients in the root systems and soil, the immediate effects of harvesting on the total nutrient pool can be estimated.

This report discusses a case study of the above-ground biomass and distribution of nine nutrients in a 15-year-old Pinus radiata D. Don (radiata pine) stand in south-eastern Victoria and, on the basis of this case study, examines biomass and nutrient research for the species.

Results were compared with published data for stands aged 10 to 26 years in other localities, and it was concluded that total tree analysis provides a precise estimate of biomass. Furthermore, there was close agreement between the various studies in proportions of biomass components. On the basis of these results, further biomass sampling appears to be unjustified, except in mature stands where data are incomplete, and existing data should now be pooled to construct generalised models for biomass prediction.

On the other hand, the comparisons showed that nutrient concentrations in biomass components varied substantially between sites. Therefore, nutrient concentrations, particularly in the major biomass components, need to be measured at a given site to avoid large errors in estimating nutrient contents.

There is still very little information available on the biomass and nutrient content of root systems, and this aspect, together with more detailed knowledge of natural accretion, natural loss and cycling of nutrients in radiata pine stands remain important areas for further study.

Also published:

Stewart, H. T. L., Flinn, D. W. and James, J .M.  (1981)  Biomass and nutrient distribution in radiata pine.  Proc. Nutr. Workshop, Prod. In Perpetuity, Canberra, Aug. 1981, pp. 173-85.