Pinus radiata

Pinus radiata Monterey Pine
Conservation status
Conservation Dependent (IUCN 2.3)
Scientific classification
Kingdom:	Plantae
Division:	Pinophyta
Class:	Pinopsida
Order:	Pinales
Family:	Pinaceae
Subfamily:	Pinoideae
Genus:	Pinus
Subgenus:	(Pinus)
Species:	P. radiata
Binomial name
Pinus radiata D.Don

The Monterey Pine, Pinus radiata, family Pinaceae, also known as the Insignis Pine^[1] or Radiata Pine is a species of pine native to the Central Coast of California.

It is the most widely planted pine in the world, valued for rapid growth and desirable lumber and pulp qualities.

Although Pinus radiata is extensively cultivated as a plantation timber in many temperate parts of the world,^[2] it faces serious threats in its natural range.^[3]

Distribution

Pinus radiata is a species of pine native to Central Coast of California, in three very limited areas located in Santa Cruz, Monterey Peninsula (Monterey), and San Luis Obispo Counties. It is also found as the variety Pinus radiata var. binata or Guadalupe Pine on Guadalupe Island, and a possibly separable P. radiata var./subspecies—ssp. cedrosensis on Cedros Island, both in the Pacific Ocean off the west coast of the northern Baja California Peninsula in Mexico.

In Australia, New Zealand, and Spain it is the leading introduced tree^{[citation needed]} and in Argentina, Chile, Uruguay, Kenya, and South Africa it is a major plantation species.

Description

Pinus radiata grows to between 15–30 m (49–98 ft) in height in the wild, but up to 60 m (200 ft) in cultivation in optimum conditions, with upward pointing branches and a rounded top. The leaves ('needles') are bright green, in clusters of three (two in var. binata), slender, 8–15 cm (3.1–5.9 in) long and with a blunt tip. The cones are 7–17 cm (2.8–6.7 in) long, brown, ovoid (egg-shaped), and usually set asymmetrically on a branch, attached at an oblique angle. The bark is fissured and dark grey to brown.

It is closely related to Bishop Pine and Knobcone Pine, hybridizing readily with both species; it is distinguished from the former by needles in threes (not pairs), and from both by the cones not having a sharp spine on the scales.

The modern tree is vastly different from the native tree of Monterey. In plantations the tree is commonly planted at 3m x 3m spacing on a wide variety of landscapes from flat to moderatly steep hills.Because of selective breeding and more recently the extensive use of Growth Factor seedlings, forests planted since the 1990s are of superior wood with very straight tall trunks without the problem of twin leaders. The trees are pruned in 3 lifts so that the lower 2/3 of a mature tree is branch- ( and hence knot-) free. In its natural state, the wood is poor quality: twisted, knotty and full of sap/resin only really suitable for fire wood, but the modern product is very different.

Ecology

Monterey Pine is a species adapted to cope with stand-killing fire disturbance. Its cones are serotinous, i.e. they remain closed until opened by the heat of a forest fire; the abundant seeds are then discharged to regenerate on the burned forest floor. The cones may also burst open in hot weather.^[4]

In its native range, Monterey Pine is associated with a characteristic flora and fauna. It is the co-dominant canopy tree together with Cupressus macrocarpa which naturally occurs only in coastal Monterey County.^[5] Furthermore, one of the pine forests in Monterey, California, was the discovery site for Hickman's potentilla, an endangered species. Piperia yadonii, a rare species of orchid is endemic to the same pine forest adjacent to Pebble Beach. In its native range, Monterey Pine is a principal host for the dwarf mistletoe Arceuthobium littorum.^[6]

A remnant Monterey Pine stand in Pacific Grove is a prime wintering habitat of the Monarch butterfly.^[7]

Conservation status

California

The three remaining wild stands of var. radiata (Monterey Pine proper) are infected and under threat of extirpation from Pine Pitch Canker caused by Fusarium circinatum, a fungal disease native to the southeast United States and found (in 1986) to have been introduced to California. When trees begin to die of the disease, they attract bark beetles which provide a pathway for infection of other trees. In some stands, 80–90% of trees are infected. If the disease is introduced in agroforestry areas dependent upon Monterey Pine, such as New Zealand, it could have catastrophic effects in those countries as well.^[2]

Baja California

On Guadalupe Island, var. binata is critically endangered. Most of the population was destroyed as tens of thousands of feral goats ate each and every seedling that germinated from the mid-19th century until just a few years ago. The older trees gradually died off until by 2001–2002 the population stood at only one hundred. With a program to remove the goats essentially complete by 2005, hundreds of young Guadalupe Pines have started to grow up in habitat fenced after 2001, the first significant new growth in about 150 years. Possible accidental introduction of Pine Pitch Canker is considered the biggest threat at present to the survival of the Guadalupe Island pine population.^[8]

Cultivation

Australia

Australia has large P. radiata plantations (though they are less than 1% of the total forested area); so much so that many Australians are concerned by the resulting loss of native wildlife habitat. A few native animals, however, thrive on them, notably the Yellow-tailed Black Cockatoo which, although deprived of much of its natural diet by massive habitat alteration through clearing for agriculture, feeds on P. radiata seeds. They are also the most common tree used for Christmas trees in Australia.

Chile

P. radiata has also been introduced to the Valdivian temperate rain forests, where vast plantations have been planted for timber, again displacing the native forests.^[9]

New Zealand

The Monterey Pine (always called Pinus radiata in New Zealand) was first introduced into New Zealand in 1859^[10][11] and today 89% of the country's plantation forests are of this species.^[12] This includes the Kaingaroa Forest on the central plateau of the North Island which is the largest planted forest in the world. Mass plantings became common from 1900 in the Rotorua area where prison labour was used. In some areas it is considered an invasive species (termed a wilding conifer) where it has escaped from plantations. It is the most extensively used wood in New Zealand.

United States

The Monterey Pine is widely used in private gardens and public landscapes in temperate California, and similar climates around the world. It is a fast-growing tree, adaptable to a broad range of soil types and climates, though does not tolerate temperatures below about −15 °C (5 °F). Its fast growth makes it ideal for landscapes and forestry; in a good situation, P. radiata can reach its full height in 40 years or so.

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  Detail of bark on a Pinus radiata tree

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  Needles and spikes on a branch

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  Pinus radiata Pine cone on forest floor

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  Monterey Pine plantation, Australia

Uses

The majority is treated with chemical salts by either dipping or pressure treatment. It is used in house construction, fencing, retaining walls, for concrete formers and to a limited extent in boat building either as weatherboards, posts, beams or plywood. For boat building, untreated ply is sometimes used but must be encased in epoxy resin to exclude moisture.

The wood is normally kiln dried to 12% moisture in 6m long, clear lengths. It is available treated with a range of chemical salts, or untreated. Chemical salt treatment is well proven and such timber is frequently used in the ground as posts and poles as part of structures such as retaining walls and pole houses. The name applied to this treatment is tanalized wood. H1 and H2 treatment is suited to indoor use. H3 is the standard house timber and this grade is used for fence palings. H4 and H5 are the standard for inground use. Lower grade timber is converted to pulp to make newsprint. Higher grade timber is used in house construction. Radiata is used chipped to make make particle board sheets, commonly used in flooring. Other sheet products are hardboard, softboard and ply. Plywood is peeled from logs in long sheets. Most ply is structural and available in 7-22mm sizes. A small amount of higher grade ply is used to produce thinner (4 and 7mm) ply suitable for furniture, cabinet work and boat building. This is knot and crack free and glued with resorcinal waterproof glue. Since the 1990s finger jointed joinery grade wood has become available in up to 6m lengths in a wide range of profiles.

Radiata holds screws and nails well and takes paint without difficulty. Modern kiln dried timber is easy to work. Young timber (under 18 years) is lighter and weaker. It is about 1/3 heavier than dried western Red cedar and about the same weight as New Zealand and Fijian Kauri. It is brittle when bent, so does not have the same load bearing features as Oregon pine (Douglas fir, Pseudotsuga).

See also

• Point Lobos Ranch

References

1. ^ Moore, Gerry; Kershner, Bruce; Craig Tufts; Daniel Mathews; Gil Nelson; Spellenberg, Richard; Thieret, John W.; Terry Purinton; Block, Andrew (2008). National Wildlife Federation Field Guide to Trees of North America. New York: Sterling. p. 84. ISBN 1-4027-3875-7. 
2. ^ ^{a b} Pinus radiata (D. Don 1836), Gymnosperm Database
3. ^ "Status of Native Monterey Pine (Pinus radiata) Ecosystems"
4. ^ [Little, Elbert L. Jr. 1980. The Audubon Society field guide to North American trees. New York: Alfred A. Knopf.]
5. ^ Hogan, C. Michael; Frankis, Michael P. (2009). "Monterey Cypress (Cupressus macrocarpa)". GlobalTwitcher.com. http://www.globaltwitcher.com/artspec_information.asp?thingid=62524. Retrieved 14 January 2011. 
6. ^ Hawksworth, F.G. and D. Wiens. 1996. Dwarf mistletoes: Biology, pathology and systematics. Agriculture Handbook 709. Washington, DC: U.S.D.A. Forest Service.
7. ^ Monarch Grove Sanctuary
8. ^ Junak, S.; Keitt, B.; Tershy, B.; Croll, D. & Sánchez, J.A. (2003). Recent conservation efforts and current status of the flora of Guadalupe Island, Baja California, Mexico. Presentation at Taller sobre la Restauración y Conservación de Isla Guadalupe ["Workshop on restoration and conservation of Guadalupe Island"]. Instituto Nacional de Ecología, November 13–14, 2003. HTML abstract
9. ^ "TEMPERATE RAIN FOREST of Chile "
10. ^ "...he first NZ introduction of British seedlings in 1859..."
11. ^ "Radiata pine", Te Ara
12. ^ "Situation and outlook for New Zealand agriculture and forestry" (PDF). NZ Ministry of Agriculture and Forestry. 2007. http://www.maf.govt.nz/mafnet/rural-nz/statistics-and-forecasts/sonzaf/archive/sonzaf-2007.pdf. Retrieved 2010-10-19. 

Further reading

• Conifer Specialist Group (1998). Pinus radiata. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 11 May 2006.
• León de la Luz, José Luis; Rebman, Jon P. & Oberbauer, Thomas (2003). On the urgency of conservation on Guadalupe Island, Mexico: is it a lost paradise? Biodiversity and Conservation 12(5): 1073–1082. doi:10.1023/A:1022854211166 (HTML abstract)

External links

• Pinus radiata at the United States Department of Agriculture
• conifers.org - Pinus radiata
• Pinus radiata at the United States Forest Service