Overview
The forecasts show the potential sustainable supply of wood available from New Zealand's planted production forests could rise from the current harvest of 18.3 million cubic metres in the year ended March 2000 to a little over 28 million cubic metres by 2003 and further increase to 30 million cubic metres by 2006. This increase assumes an average rotation length of 28 years for radiata pine.
In the year ended March 2000 New Zealand's total mix of forest products exports were produced from 12.1 million cubic metres of wood. With domestic demand relatively static the potential increase of up to 12 million cubic metres by 2006 would double the quantity of forestry exports New Zealand could produce.
Based on the forest estate currently planted New Zealand's long-run annual sustainable harvest should reach about 35 million cubic metres by 2020.
The volume of pruned logs is forecast to increase three-fold from 1.5 million cubic metres in 2000 to around 5 million cubic metres in 2006 assuming an average clear fell age of 28 years for radiata pine. Radiata pine makes up between 92 to 95 percent of the forecast wood supply over the forecast horizon.
It is important to note that the forecasts presented in this report are based solely on the available supply of wood. There has been no attempt to match this supply to the international demand for forest products. The report "Asia-Pacific Forestry Sector Outlook Study" (FAO, 1998) provides an overall description of the wood demand and supply situation for the Asia-Pacific region. This report is available on the FAO Internet Site:www.fao.org/forestry/fon/fons/outlook/Asia/apfsos/apfsos-e.stm
The forecasts were developed using models with the objective of maximising future volume harvested, subject to certain constraints.
This study uses six scenarios to show the outcome of a
range of options on the long-term, sustainable supply of wood. Three clearfell age
scenarios:
• base cut
• early cut
• late cut
are based on the age of harvesting and assume no new planting.
Three new planting scenarios:
• plant 20 000 ha/year
• plant 40 000 ha/year
• plant 60 000 ha/year
are based on a range of new planting levels. The primary assumptions for each of these
scenarios are shown in table 1.
Table 1: Primary Assumptions for Each Scenario
| Scenario | Target clearfell age for radiata pine (years) |
Area of national new planting (ha/year) |
||
|---|---|---|---|---|
| base cut | 28 | 0 | ||
| early cut | 25 | 0 | ||
| late cut | 35 | 0 | ||
| plant 20 000 ha/year | 28 | 20 000 | ||
| plant 40 000 ha/year | 28 | 40 000 | ||
| plant 60 000 ha/year | 28 | 60 000 | ||
Radiata pine was modelled on a non-declining yield basis in all scenarios, and all areas clearfelled are assumed to be replanted in the year following clearfelling.
The early and late cut scenarios provide estimates of upper and lower bounds within which the future level of harvest is expected to fall. These clearfell age scenarios show the effect of selecting different target clearfell ages on the long-run wood supply when it is managed on a sustainable yield basis. The current outlook suggests that the future harvest from New Zealand's planted forests is likely to fall between the base cut and late cut scenarios in the short to medium term. Market demand, labour and capital capacity constraints may make it difficult to lift the level of harvest as quickly as the early or base cut scenarios indicate is possible.
Graph 1: Actual and Forecast Harvest from New
Zealand's Planted Forests
Notes:
1. The vertical line indicates the beginning of the forecasts (2000).
2. Source of actual harvest volumes: 1997 New Zealand Forestry Statistics (1951 to 1996),
Ministry of Agriculture and Forestry, 1998. Statistical Release 17/2000 (1997 to 2000),
Ministry of Agriculture and Forestry, 2000
Graph 1 shows the wood supply forecasts in the context of historical levels of harvesting since 1951. This graph illustrates that the increase in the rate of harvesting that began in 1989 will continue until around 2005 under the base cut scenario. While there have been major structural changes in the ownership of planted forests during the 1990's, the primary reason for the increase in forecast harvest is due to the significant areas of forests planted from the early 1970s to the mid-1980s reaching harvestable age. During the 15-year period 1971 to 1986 an average 45,000 hectares of new forest was established each year.
Separate forecasts were carried out for each of the ten wood supply regions: Northland; Auckland; Central North Island; East Coast; Hawkes Bay; Southern North Island; Nelson & Marlborough; West Coast; Canterbury; and Otago & Southland. These were then aggregated to provide the national forecasts summarised in table 2.
Table 2: National Wood Supply Forecasts (Average Annual Recoverable Volumes Million Cubic Metres/Year)
| Year/ Lustrum |
Base cut | Early cut | Late cut | Plant 20 000 ha/year |
Plant
40 000 ha/year |
Plant
60 000 ha/year |
|---|---|---|---|---|---|---|
| 2000 | 18.4 | 18.4 | 18.4 | 18.4 | 18.4 | 18.4 |
| 2001 | 19.9 | 21.0 | 19.9 | 19.9 | 19.9 | 19.9 |
| 2002 | 25.2 | 31.0 | 20.2 | 25.4 | 25.4 | 25.4 |
| 2003 | 28.6 | 30.9 | 20.5 | 28.6 | 28.6 | 28.6 |
| 2004 | 28.8 | 30.9 | 20.5 | 28.7 | 28.7 | 28.7 |
| 2005 | 28.8 | 31.0 | 20.9 | 28.8 | 28.8 | 28.8 |
| 2006-10 | 30.8 | 31.8 | 24.4 | 30.8 | 30.8 | 30.8 |
| 2011-15 | 31.0 | 32.2 | 30.2 | 31.2 | 31.3 | 31.4 |
| 2016-20 | 33.1 | 33.2 | 32.3 | 33.4 | 33.7 | 34.0 |
| 2021-25 | 34.4 | 33.4 | 33.6 | 38.0 | 38.9 | 39.8 |
The forecast for each of the clearfell age scenarios rises steeply between 2000 and 2010. In the long term each scenario reaches a plateau where the annual recoverable volume becomes reasonably constant indefinitely. Table 3 summarises these levels and the years they are reached.
Table 3: Maximum Recoverable Volumes Forecast for the Clearfell Age Scenarios
| Scenario | Target age of radiata pine (years) |
Maximum recoverable volume (million m3/yr) |
Year available from |
|---|---|---|---|
| Base cut | 28 | 34.5 | 2020 |
| Early cut | 25 | 33.3 | 2018 |
| Late cut | 35 | 36.6 | 2036 |
The new planting scenarios show the outcome of different levels of new planting on the long-run forecast wood supply. The new planting scenarios are based on the results of a survey of new land planting intentions for the period 2000 to 2010 undertaken by the Ministry of Agriculture and Forestry in 1999. Graph 4 (see page 27) shows historical rates of new planting. The plant 40 000 ha/year scenario is the currently accepted best estimate of future new planting. The other two new planting scenarios provide likely estimates of lower and upper bounds.
The impact of future new planting does not begin to materially increase the wood supply until 2020.
The wood supply forecasts for the new planting scenarios do not reach a steady state plateau since new areas of forest are continuously established over the forecast horizon (see graph 2).
Graph 2: Forecast Wood Supply from New Zealand's
Forests Assuming Constant New Planting
The Central North Island is the dominant wood supply region in New Zealand, producing 57 percent of the national wood supply in 2000. The Central North Island will remain the dominant wood-producing region. Although the potential increase in wood supply is small relative to the current levels of harvest the annual cut is still forecast to increase by nearly two million cubic metres by 2010.
Based on the forests currently planted the forecasts show increases in potential wood supply in all parts of New Zealand. The largest increases are in Northland, the East Coast, Hawkes Bay, and the Southern North Island regions. These regions show very large increases in wood supply compared to current harvest levels. The large increases are forecast to occur over relatively short periods of time.
The regional forecasts are summarised in table 4 and graph 3.
Table 4: Actual (1999) and Base Cut Forecast (2000 to 2025) (Millions Cubic Metres/Year)
| Wood supply region | Actual harvest 1999 |
Base cut forecast 2000 |
Base cut forecast (5 year averages) | ||||
|---|---|---|---|---|---|---|---|
| 2001-05 | 2006-10 | 2011-15 | 2016-20 | 2021-25 | |||
| Northland | 1.0 | 1.2 | 3.5 | 4.1 | 4.1 | 4.1 | 4.0 |
| Auckland | 0.6 | 0.7 | 0.9 | 0.9 | 0.9 | 1.0 | 1.0 |
| Central North Island | 9.6 | 10.3 | 10.2 | 11.7 | 11.6 | 11.8 | 12.0 |
| East Coast | 0.6 | 0.7 | 1.6 | 2.6 | 2.8 | 3.4 | 3.4 |
| Hawkes Bay | 0.6 | 0.8 | 1.7 | 2.4 | 2.4 | 2.6 | 2.7 |
| Southern North Island | 0.5 | 0.6 | 2.0 | 2.5 | 2.3 | 3.0 | 3.4 |
| Nelson & Marlborough | 1.3 | 1.4 | 2.5 | 2.7 | 2.9 | 3.0 | 3.1 |
| West Coast | 0.2 | 0.2 | 0.3 | 0.4 | 0.4 | 0.4 | 0.4 |
| Canterbury | 0.5 | 0.6 | 1.2 | 1.2 | 1.2 | 1.3 | 1.5 |
| Otago & Southland | 1.5 | 1.8 | 2.2 | 2.3 | 2.4 | 2.6 | 3.0 |
| New Zealand total | 16.5 | 18.4 | 26.3 | 30.8 | 31.0 | 33.1 | 34.4 |
Note:
The sum of the regions may not exactly equal the New Zealand totals due to rounding.
Increased growth rates from using genetically improved planting stock have not been directly included in any of the forecast scenarios. The long-term wood supply forecasts presented are considered to be conservative without the inclusion of genetic improvement.
It should be recognised that the harvest from New Zealand's planted forests is not regulated by the artificial regional boundaries used in this study. Planted forests are managed to maximise the benefits to the enterprise that owns them.
The forecasts in this report are essentially resource-based forecasts of the level of harvest attainable given the assumptions on yields, areas and harvesting constraints. This is not a prediction of how forest owners will manage the cut from their forests, nor is it a prescription for how their cut should be managed.
