Pinus radiata (syn. Pinus insignis), the Monterey pine, insignis pine
Pinus radiata is a versatile, fast-growing, medium-density softwood, suitable for a wide range of uses and valued for rapid growth (up to two meters (6.5 feet) in one year), as well as desirable lumber and pulp qualities.
Although P. radiata is extensively cultivated as a plantation timber in many temperateness parts of the world, it faces serious threats in its natural range, due to the introduction of a fungal parasite, the pine pitch canker ( Fusarium circinatum). The pine shoot moth Rhyacionia buoliana is another serious problem. In cultivation in New Zealand, Pinus radiata has grown as much as in 41 years, an average of per year.
The specific epithet radiata refers to the cracks which radiate from the umbo of the cone scales.
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 plantation tree is vastly different from the native tree of Monterey.
In Mexico, it is found on two islands in the Pacific Ocean, Guadalupe Island and Cedros Island. On Guadalupe Island, located off the mainland coast, the pines are found on the steep northern end of the island, at elevations of around , where they follow the ridgetops and steep slopes. On Cedros Island, the pines are more abundant, being found in far greater numbers partly due to the lack of . They are found at lower elevations than on Guadalupe, at around , on the windward ridges and canyons of the north and central parts of the island. In both cases, the pines seem to be heavily dependent on locations with a high frequency of fog.
In Australia, New Zealand, and Spain it is the leading introduced treeScott, C. W. 1960. Pinus radiata. Food and Agriculture Organization of the United Nations, Forestry and Forest Products Study 14. Rome, Italy. 328 p. cited in . and in Argentina, Chile, Uruguay, Kenya, and South Africa it is a major plantation species. It is also an introduced tree on the world's most remote inhabited island, Tristan da Cunha.
On both islands it is the only pine species, and one of the few tree species. Compared to the mainland species, which are mostly three-needled, the insular varieties have their needles in bundles of two. Their cones are also smaller, and they show greater wind resistance in regards to wind-induced toppling.
In its native range, P. radiata is associated with characteristic flora and fauna. It is the co-dominant canopy tree, together with Cupressus macrocarpa, which also naturally occurs only in coastal Monterey County. 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, P. radiata is a principal host for the dwarf mistletoe Arceuthobium littorum.
The habitat of the pines on Cedros Island contrasts greatly with the desert scrub on other parts of the island, forming Ecotone of abrupt transition. The numerous groves form a mostly-monotypic forest of the species, with very few other plants besides seedlings emerging in the understory. In some areas, the edges of the forest form a zone that supports chaparral species, including Malosma, Diplacus stellatus, and the endemic Eriogonum molle. With their large surfaces to Condensation fog, the pines create irrigation for themselves and their associates. Towards the far northern end of the island, a Succulent plant community mostly consisting of Dudleya is found, and the endemic Dudleya pachyphytum can sometimes be found growing under the pines in the ecotone.
A remnant P. radiata stand in Pacific Grove, the Monarch Grove Sanctuary, is a prime wintering habitat of the monarch butterfly.
In South Africa, the tree is a threat to already scarce water resources. The tree has remarkable roots. Monterey pine roots will reach downward as far as physically permitted by subterranean conditions. Roots have been discovered up to long. Efforts to remove large quantities of the non-native tree in areas of South Africa have resulted in significant increases in accessible water.
Sphaeropsis blight ( Diplodia pinea) infects P. radiata in California and causes serious damage to plantations of the species in New Zealand, Australia and South Africa, especially after hail damage to growing tips.
Use of pine in construction did not become widespread until forced by wartime shortages. It had been used in Southland from about 1920, but doubts were being expressed about it as late as 1945, when at least one MP considered it only suitable for interior studding. Experiments in pressure treatment with water-soluble preservatives were made from 1943.
Pinus radiata forests have a negative effect on local ecology. In its plantations there are usually no other tree species, while its shady undergrowth does not allow the existence of a rich stratum of scrub. 13% of the wood cut annually in Spain comes from this pine. Los pinares de pino radiata Los pinares de pino radiata Ministerio de Medio Ambiente. Gobierno de España.
Pinus radiata is used in house construction as weatherboards, posts, beams or plywood, in fencing, retaining walls, for concrete formers. It is also used to a limited extent in boat building where 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 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. In New Zealand, a 1995 change to no longer require borate treatment in house framing timber was a key factor in the leaky homes crisis, but since 2003 a series of changes have now improved the regulations.
Lower grade timber is converted to pulp to make newsprint. Higher grade timber is used in house construction. P. radiata is used chipped to make particle board sheets, commonly used in flooring. Other sheet products are hardboard, softboard and ply. Most ply is structural and available in sizes. A small amount of higher grade ply is used to produce thinner () ply suitable for furniture, cabinet work and boat building. This is knot and crack free and glued with Resorcinol glue. Since the 1990s finger jointed joinery-grade wood has become available in up to lengths in a wide range of profiles.
In 1958, New Zealand boat designer Des Townson started building 186 , cold-moulded Zephyr-class dinghies, using P. radiata. In 2011 these hand-built boats fetched very high prices and were generally in excellent condition.
The bark is used as a substrate for potting and re-potting orchids.
Pinus radiata is the most common species of Christmas tree in Australia and New Zealand.
In California, P. radiata is commonly planted to block wind or noise, or for ornamental reasons.
Taxonomy
Subdivisions
Ecology
Conservation status
Fungal disease
Baja California
Cultivation
Australia
Chile
New Zealand
Spain
United Kingdom
United States
Uses
Bibliography
External links
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