Pinus Radiata once an obscure botanical oddity clinging to existence on the California coast has become New Zealand's great timber tree.

Also known as Monterey, Insignis and New Zealand Pine is a fast growing softwood tree that responds well to intensive management. Its versatility makes it useful for a wide range of applications and processes.

Radiata pine is native to a small coastal area of central California, where it is now a threatened species. However it is now widely spread throughout the Southern Hemisphere, with greatest concentrations in New Zealand, Australia, Chile and South Africa. It is commercially cultivated in each of these countries, as well as Spain, France, Argentina, Greece and India.

The tree grows in a variety of conditions but especially suits well-drained slopes with soils of medium fertility.

New Zealand and Chile have the largest Radiata resources, with both countries having estates approaching 2 million hectares (5 million acres) or renewable, environmentally sustainable, plantation forests.

Both countries enjoy favourable growing conditions for the species, with growing cycles of 25 to 30 years, from planting to maturity. Harvesting of immature trees is common depending on economic returns.

New Zealand tends to manage its plantation trees more intensively, pruning trees to produce a high proportion of higher value clearwood timber.

New Zealand plantation forests have benefited from genetic improvements through selective breeding programmes since the 1960's. Early improvements focussed on developing growth and form characteristics. Today the programmes concentrate on specific traits including disease resistance, straight grain and internodal distance.

Germination

Science can offer the forest industry many new ways of improving the quality of the trees, as well as improving the efficiency of the production cycle. These new technologies give us many advantages but still ensure we retain a broad genetic diversity in our forest estate.

Radiata pine trees have not always been the tall, elegant specimens we see in the forest today. Similar to human beings, they tend to grow in all shapes and sizes, depending on their inherited genetic blueprint. Foresters, however, want to make sure that they are growing only the best quality trees, with the most desirable features. The features that qualify as desirable depend a great deal on the market or end use the wood is destined for, but generally include straight grain, small branches, fast growth rate and disease resistance. Fortunately radiata pine has a high degree of genetic variability which allows for successful genetic breeding to enhance these features.

Controlled pollination allows seeds to be germinated from known parent trees with desirable qualities. The immature cones from selected trees in special seed orchards are sealed in plastic bags. Pollen from other trees is introduced by hand, cones form and after two years the seed is ready to harvest.

Every year the New Zealand industry plants as many as 90 million new seedlings to replace those trees that have been harvested and to extend the area of forest. The seeds are sown during the spring in specially prepared beds. They will remain there for up to nine months before they are hand lifted and transplanted in the forest.

Not all seedlings are grown from seeds. Pinus radiata can be grown from cuttings. This method is used to extend the scarce high quality seed by as many as a 100 times.

Planting & Establishment

Planting occurs during the winter months from May to August. All harvested areas will be replanted within 12 months. Our forests are hand planted to ensure careful handling of the seedlings and because of the often hilly and uneven terrain where the forests are situated. It is skilled work planting anywhere between 500 and 1,000 seedlings per day.

The seedlings are still only very young, about nine months old, and vulnerable to the hazards of life in the forest. Pests such as rabbits and possums, weeds such as gorse, broom and pampas, and diseases can threaten the young seedlings before they have had the chance to establish themselves

Prior to planting, the site will be prepared to assist the seedling survival rate and promote early growth. This may involve clearing, cultivation, or weed control. The ground and weeds around the young seedling are cleared at intervals during the first two years to keep the competing vegetation at bay.

Between 600 and 1500 seedlings are planted on each hectare depending on the planned use of the mature trees, the genetic quality of the seedlings and planting site conditions.

Pruning and Thinning

Silviculture is the term used to cover the tending of the forest to produce the types of tree required for various end uses. The silvicultural regime will differ depending on the expected use of the tree. The two main tree-tending operations are pruning and thinning.

Pruning occurs when the tree is between four and seven years old and is done by hand. By cutting off the lower branches at a young age, the tree will grow to produce high-value, knot-free timber in that part of the stem. After pruning, the new wood grows over the stubs of the removed branches to produce clearwood, or knot-free wood. The pruning contractor needs to remove the branches as close to the tree stem as possible. Tree stems are pruned to 6.5 metres from the ground but the pruning height will vary depending on the height and diameter of the tree. Pruning aims to leave 3-4 metres of green crown foliage on each young tree each time it is pruned - sufficient to maintain tree growth.

Pruning also improves disease control, helps with forest access and reduces the spread of fire. Thinning is the process of cutting out some of the trees in the forest to reduce competition and allow the larger or better formed trees to grow to maturity. Thinning is generally carried out at the same time as the pruning stage. Trees are thinned if they have defects that will reduce the final value of the tree, or if they are too small.

Harvesting

Harvesting certainly is one of the most visible operations and requires the most machinery and manpower to complete. But it is just another element in the cycle of a plantation forest.

It is the logger's job to safely and efficiently harvest the forest to produce the logs to the required volumes and quality specifications to meet the customer's demands. To do this a variety of different methods are used to move the felled trees to log landings with specially constructed access for logging trucks . Tractors and wheeled skidders are used to pull the trees out on to flatter ground and cable hauling machines are used on steeper country. At the central processing area the trees are cut into logs for the mills. It is a skilled job to ensure that the most value is cut from each tree. The use of these central processing areas, or log landings, during harvesting concentrates activity and reduces forest disturbance.

Logging requires a highly skilled and professional workforce to ensure that operations are carried out safely. Loggers work to national standards and contractor qualifications are actively encouraged.

Harvesting has the potential to affect the natural environment through soil disturbance and erosion, but these are kept to a minimum by professional forest management, good planning and adherence to strict environmental standards. Vegetation surrounding streams and water courses is preserved where possible and the size of felled areas is controlled to reduce erosion.

All harvested land is replanted within 12 months of felling, starting the forest cycle all over again.


Some Common Uses

Radiata has become appreciated for its suitability for a wide range of uses. In the past, before harvest of pruned trees began providing clearwood on a significant scale, the lower grade, unpruned timber was most suitable for low grade applications including: construction, form work, packing cases, panelling, pulp / paper products, pulpwood, building materials, housing construction, fibre board and MDF and plywood veneers.

More recently as clearwood has become available the range of uses has expanded into higher end uses, including furniture, veneer and mouldings. Accordingly perception and use of radiata has improved and continues to improve.

Applied technological processes have also provided an extended range of uses. A process developed by Forest Research to harden radiata is being used to make it ideal for flooring and furniture.

Summary of Key Points

Radiata pine is reported to be steadily growing as a replacement for the more expensive Ponderosa pine and Douglas fir in the United States and Japan.

Radiata pine timber seasons easily and rapidly at high temperatures (commercially up to 120 degrees C) with medium shrinkage. The use of kilns for drying is common practice in New Zealand, particularly for drying clearwood timber.

The timber is susceptible to staining and decay unless treated promptly. Timber for use in wet or external conditions needs to be chemically treated with preservatives. New Zealand Forest Research has made significant advances in developing environmentally acceptable treatments.

Strength Comparison

WEIGHT HARDNESS COMPARISON STRENGTH (MCS) BENDING STRENGTH (MDR) STIFFNESS (MDE) WHEN COMPARED TO THE FOLLOWING SPECIES 31% lighter 54% softer 23% weaker 19% weaker 23% less stiff Pecan 20% lighter 18% softer 20% weaker 19% weaker 13% less stiff Teak 50% lighter 75% softer 55% weaker 50% weaker 45% less stiff Ekki 34% lighter 46% softer 25% weaker 13% weaker 24% less stiff Iroko 3% heavier 2% harder 6% weaker 4% weaker 6% less stiff Honduras mahogany 31% lighter 39% softer 18% weaker 27% weaker 25% less stiff White oak 58% lighter 81% softer 47% weaker     Lignumvitae 50% lighter 68% softer 53% weaker 56% weaker 61% less stiff Greenheart 48% lighter 77% softer 54% weaker 57% weaker 57% less stiff Lapacho 190% lighter 842% harde 77% stronger 50% stronger 43% stiffer Balsa

 

Typical Log Out-turn

• HOME

• ABOUT US

• NZ FORESTRY

• THE SPECIES

• AS AN INVESTMENT

• ENVIRONMENT

• PARTNERS

• PHOTOGRAPHS

• LINKS

TRUSTWOOD FORESTS
(NZ) LIMITED

Peninsula Road, Onemana
New Zealand.

PO Box 21, Whangamata
New Zealand

 Phone +64 7 865 6944