2 Overview

New Zealand's planted production forests covered an estimated 1.81 million hectares as at 1 April 2005. This area is estimated to be accurate to plus or minus 5 percent. That is, the total area (net stocked) is estimated to be between 1.72 and 1.90 million hectares. For further information refer to Chapter 5, "Reliability of Data".

The total standing timber volume (growing stock) is estimated to be 400 million cubic metres with an average forest stand age (area weighted) of 13.9 years.

Table 2.1 provides key national forest resource statistics as at 1 April 2005 and compares these with statistics for 2004.

Seventy percent of the forest area is in the North Island and 30 percent is in the South Island. Thirty-one percent of the entire planted forest estate is in the Central North Island wood supply region.

Figures 8.1 and 8.2 show the location of New Zealand's planted forests as identified in the New Zealand Land Cover Database version 2 (NZLCDB2). Figures 9.1 and 9.2 show the ownership of the major forests in New Zealand. Further forest ownership information is available on the New Zealand Ministry of Agriculture and Forestry's website (www.maf.govt.nz).

Figure 2.1 shows the age structure of the New Zealand planted forest estate. Very little of the forest area is planted in trees older than 32 years, a reflection of the economic rotation age of the dominant species, radiata pine. Radiata pine is typically harvested between 26 and 32 years old. The figure shows that the areas of forest planted from the late-1970s to the mid-1980s are now approaching harvest age. Also, the large areas of forest planted between 1992 and 1998, now seven to 13 years old, are very apparent. Harvesting of these areas will begin around 2020.

Species and Silviculture

Radiata pine is the dominant species, making up 89 percent of the planted forest area. Douglas-fir is the next most common species, making up 6 percent. The remainder of the area is planted in cypresses, eucalypts, other softwood and hardwood species.

About 63 percent (just over one million hectares) of the radiata pine planted forest estate is, or is expected to be, pruned to a height of at least four metres. Approximately 10 percent (100 000 hectares) of pruned radiata pine is older than 25 years, while 16 percent (168 000 hectares) of pruned radiata pine is between 21 and 25 years old. Seventy-four percent (751 000 hectares) of the pruned radiata pine is 20 years old or under.

Figure 2.1: Total Estimated Planted Production Forest Area by Age Class, as at 1 April 2005¹

Total Estimated Planted Production
Forest Area by Age Class, as at 1 April 2005

1. The area is shown for each age in single years up to 35 years. After this, five-year age classes are shown.

The area of production thinned forest has declined in recent years. Approximately 17 percent of the radiata pine planted forest currently is, or is expected to be, production thinned. In 1995, 28 percent of the radiata pine forest was, or was intended to be, production thinned. Production thinning of the radiata resource has decreased in the Central North Island region from 65 percent in 1995 to 22 percent in 2005.

Figure 2.2: Species Distribution - 2005

Species Distribution - 2005

New information collected in the 2005 survey indicates that 52 percent of the forest resource is first rotation forest, 28 percent is second or subsequent rotation, while information is incomplete for 20 percent of the estate. Of the identified first rotation forest, 53 percent is aged 15 years or under.

Planting

An estimated 10 600 hectares of new forest were established in 2004. It is provisionally estimated that 6000 hectares of new planting occurred during 2005.

The average new planting rate over the last 30 years has been 43 000 hectares per year. In the period 1992 to 1998 new planting rates were high - averaging 69 000 hectares per year. Since 1998 new planting has declined. At 6000 hectares in 2005, new planting is at its lowest level since 1960.

Figure 2.3: Radiata Pine by Tending Regime - 2005

Radiata Pine by Tending Regime -
2005

It is estimated that between 1990 and 2004, 671 000 hectares of new forest were established. New entrants to forestry have carried out much of this new planting. While these new owners have planted a significant area of forest during the 1990s, 70 percent (1.3 million hectares) of the entire forest resource is still currently owned by growers with more than 1000 hectares of forest.

Figure 2.4: New Forest Planting - 2005

New Forest Planting - 2005

Deforestation

The relatively new trend of not replanting forest after harvesting, and in a few cases converting immature forest to pasture, started on a larger scale in 2004. New Zealand has always had a relatively dynamic landscape, so changes in land-use are not unusual. However, historically little conversion of planted production forest land has occurred. The 2005 survey indicates that approximately 7000 hectares of forest clear felled in the year ended 31 March 2005 will not be replanted. This area represents 18 percent of the area harvested, and compares with historical information indicating that only about 2 to 3 percent of the area harvested has not been replanted in the past.

Table 2.1: National Exotic Forest Estate Statistics

Area and standing volume statistics	As at 1 April 2004 ¹		As at 1 April 2005
Net stocked forest area
Total area (ha)	1 822 000		1 811 000
Growth characteristics
Standing volume (000 m³)	398 000		400 000
Average standing volume (m³/ha)	219		221
Area-weighted average age (years)	13.7		13.9

Area by species
Radiata pine (ha)	1 626 000		1 611 000
Douglas-fir (ha)	112 000		115 000
Cypress species (ha)²	na		6 000
Other softwoods (ha)	33 000		28 000
Eucalyptus species (ha)³	na		33 000
Other hardwoods (ha)	51 000		18 000

Radiata pine area by tending regime
Pruned with production thinning (ha)	256 000		226 000
Pruned without production thinning (ha)	798 000		793 000
Unpruned with production thinning (ha)	40 000		40 000
Unpruned without production thinning (ha)	532 000		551 000

Planting statistics	Year ended 31 December 2003¹		Year ended 31 December 2004
New planting
Total estimated new planting (ha)⁴	19 900		10 600
Restocking (ha)	38 200		39 600
Harvested area awaiting restocking (ha)	54 600		42 700

Harvesting statistics	Year ended 31 March 2004¹		Year ended 31 March 2005
Harvesting
Area clear felled - all species (ha)	40 800		39 000
Area clear felled - radiata pine (ha)	38 100		36 200

Volume clear felled - all species (TRVIB5, 000 m³)	18 550		17 580
Volume clear felled - radiata pine (TRVIB, 000 m³)	17 541		16 725
Volume production thinned - all species (TRVIB, 000 m³)	826		719
Total volume removed - all species (TRVIB, 000 m³)	19 376		18 299

Average clear fell yield - all species (m³/ha)	455		450
Average clear fell yield - radiata pine (m³/ha)	460		462

Area-weighted average clear fell age for radiata pine (years)	27.6		27.9

Estimated planted forest roundwood removal (000 m³)⁶	20 854	^R	19 234

Notes

1. Source: A National Exotic Forest Description as at 1 April 2004, Ministry of Agriculture and Forestry, 2005.
2. In the 2004 NEFD survey, "Cypress species" were included in the "Other softwoods" category.
3. In the 2004 NEFD survey, "Eucalyptus species" were included in the "Other hardwoods" category.
4. The method used to estimate new planting is described on page 6 of this report.
5. Total recoverable volume inside bark.
6. Source: Ministry of Agriculture and Forestry, February 2006. This is an indirect estimate based on the application of conversion factors to the various forestry products and is included here as a comparison with the direct estimate of the total volume removed from the 2005 NEFD Survey.

Symbols

na not available
R revised

Harvesting

An estimated 18.3 million cubic metres of roundwood were harvested from New Zealand's planted production forests in the year ended 31 March 2005. An estimated 17.6 million cubic metres came from clear felling 39 000 hectares of planted forest, and 0.7 million cubic metres from production thinning.

The radiata pine harvest comprised approximately 68 percent unpruned logs, 21 percent pulp and chip logs and 11 percent pruned logs. About 39 600 hectares of previously clear felled planted forest were replanted in 2004.