Southern North Island wood availability forecasts for the period 2008–2040
Data
Method used to obtain forest areas
The forest area was obtained from the NEFD as at 1 April 2006 (MAF 2007). The small-scale owners’ estate was reduced by 15 percent (apart from some investment syndicates including those managed by Forest Enterprises). This was done because the area in this ownership category is often reported on the basis of gross area rather than net stocked area (which excludes unplanted areas, areas not successfully established, streams, wetlands, and so on).
Method to develop yield tables
In 2007 new yield tables for both the Western and the Eastern SNI were developed in the following way:
- large-scale owners (and Forest Enterprises) provided yield tables for their estate;
- these were averaged on an area-weighted basis to get regional yield tables for each croptype;
- yield tables for old (age 17+ years, planted in 1989 and earlier) radiata pine and Douglas-fir were then calibrated to match the harvest intentions data provided by large-scale owners (and Forest Enterprises); that is, the assumption is that the harvest intentions data is the most accurate information available as it is based predominantly on detailed inventory;
- yield tables for young radiata pine croptypes (planted in 1990 and later) were also adjusted in consultation with large-scale owners;
- the yield tables developed for the large-scale owners’ estate were also applied to the small-scale owners’ estate.
Large-scale owners harvest intentions
Large-scale owners were asked to provide details of planned harvest volume by log grade and area from 2006 to 2015. These harvest intention values were then included at the beginning of the forecasts to provide the most realistic wood availability forecasts over this period.
Small-scale owners harvest intentions
The major companies and consultants involved with the small-scale owners were asked to provide details of harvest volumes from 2006 to 2008. The actual grade breakdown was not available, so the breakdown derived from the large-scale owners was used. No predictions beyond 2008 were available for these owners.
Presentation of results
This report is structured to present the western side of the region separately from the eastern side, before presenting the forecasts for the whole SNI region.
Contact for Enquiries
Policy Adviser
Pastoral House
MAF Policy
PO Box 2526
Wellington 6140
NEW ZEALAND
Fax: +64 4 894 0741
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