Australian plantation inventory: ownership changes, availability and policy

Summary

The Australian National Plantation Inventory has collected and collated plantation information since 1993 and has periodically published forecasts of availability based on those data. This paper outlines the past methodology and summarises updates of the most recent forecasts. The failures of some managed investment scheme (MIS) forestry companies have drawn attention to the risks and difficulties involved in forecasting plantation wood yields for species and areas where few data are available. These issues have important implications for forecasts of availability but several unknowns still exist, especially in relation to future replanting. The accuracy of prospectus forecasts of yields from several MISs is examined. The methods used in national and selected regional forecasts are reviewed and some of the underlying policy issues for Australian plantations and forestry are critically examined.

Keywords:

• plantations
• inventories
• availability
• forecasts
• growth
• yields
• investment
• policy

Acknowledgements

Special thanks go to Claire Howell, Mark Parsons and Stuart Davey and Blair Freeman for their comments. The work of these four and of others in ABARES in maintaining the present form of the NPI merits special recognition. The participants of the plantation growing and management sector also merit thanks for their significant ongoing commitment and contribution to the NPI since its establishment in the mid-1990s.

A preliminary version of this paper was presented at the 2011 ANZIF conference in Auckland. In the course of this revision, data errors were discovered in MIS data supplied by a confidential source. Most of the results still hold but reporting of some results with low sample numbers could no longer be justified. The author takes sole responsibility for the views expressed and acknowledges a vested interest as a director of a major softwood plantation company.

Notes

1. This section draws heavily on Ferguson et al. (2011).

2. The Independent Forester’s Report (p. 34) of the Timbercorp (2005) Product Disclosure Statement states that ‘Timbercorp Forestry advises that only land that in aggregate with all other land in the Project will continue to provide the target weighted average yield of 275 m³ of pulpwood per hectare between 8 and 12 years after planting will be included in the Project’.

3. In subsequent correspondence, Knott estimated the following function for merchantable volume (y) at age 10 years based on average annual rainfall following planting (Rf) and 1612 plots: y = –1084.5 + 184.74*log(Rf). This is substantially lower than Equation (1), but somewhat closer to Equation (2) for lower rainfall. Unlike those equations it shows diminishing returns for high rainfall.

4. Experimental sites are generally better than average and more uniform in site productivity than a large plantation estate. Local geographic or temporal variations in climate, treatment, and the depredations of pests and diseases all contrive to lower yields in the latter relative to the former.

5. The distinction between ‘new planting’ (i.e. planting of land previously in other uses) and ‘replanting’ (i.e. planting of land previously under plantations) is important, as later discussion will show. For simplicity, coppice regeneration is included under the heading of planting.

6. Former students of Dr Max Jacobs may be prompted to remember his cautionary tale of why tropical coastal forests in North Queensland fail to attain the height of their southern counterparts, despite generally better growing conditions.

7. This and all subsequent figures are based directly on data from Gavran et al. 2012.

8. September 2012 press reports suggest that total Western Australian exports for the past year were equivalent to about 2.5 million m³ log volume, while those for the Green Triangle were about 1.8 million m³.