Philip M. McDonald and Robert J. Laacke
Monterey pine (Pinus radiata) is the most widely planted pine in the world (9). Rapid growth and desirable lumber and pulp qualities cause it to be the leading introduced species in Australia, New Zealand, and Spain (34), and a major species in plantations of Argentina, Chile, Uruguay, Kenya, and the Republic of South Africa. In these countries, Monterey pine is a mainstay of the forest economy, serving internal markets, generating valuable foreign exchange reserves as an export, and reducing cutting pressure on native forests.
Pinus radiata was first noted by Thomas Coulter at Monterey, CA, in 1830. The scientific name refers to the strong markings on the cone scales, and the common name to the peninsula on which it grows extensively. Other common names are insignis pine and radiata pine. Radiata pine is a common name increasingly used worldwide; pino insigne is the Spanish equivalent.
General: Pine family (Pinaceae). Monterey pines are native to California and Baja California where they occur in only a few small populations. Mature Monterey pines can reach 38 m in height with trunks up to 2 m in diameter. The young trees begin as compact pyramids but age into varied shapes. The adult canopy is usually rounded to flat-topped. Along the Pacific coast, the winds sculpt Monterey pine canopies into picturesque shapes. The bark is red-brown to blackish brown and has deep furrows. The leaves are glossy, dark green needles, 6-15 cm long that grow in bundles of three. Needles on older trees are sometimes a bluish green. Flowers appear in late winter or early spring. The trees are monoecious; having both male and female flowers (McDonald & Laacke 1990). The yellow male catkins are 12mm long and are generally found on the lateral branches. Female flowers grow throughout the entire canopy. The grayish brown cones are asymmetrically oval, 6 to 15 cm long, and are born on short stalks in clusters of 3 to 7 cones. The scales are smooth and rounded. Each cone contains from 120 to 200 dark brown to black, bumpy winged seeds that are 6-7mm long. The cones remain closed on the tree until the second year or sometimes longer. Cones generally ripen and open from late winter to early spring of the second year. Thereafter, they may remain on the tree where they can open and close several times depending on temperature and moisture. The close-grained wood is light and soft. Although it is not considered an important lumber tree in California, it has been widely planted in areas with Mediterranean climates throughout the world for use as lumber and pulp.
Distribution: Monterey pines are native to California and Baja California. Native Monterey pine forests occupy a small portion of their historical range and are currently restricted to five coastal locations: Año Nuevo in the north, the Monterey Peninsula, Cambria, and on Guadalupe and Cedros islands off the coast of Baja, California in the south.
For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site.
Habitat: Monterey pines grow below 1200 meters in closed cone pine forests and oak woodlands. The species is one of the 18 California species of pines and cypresses that bear closed cones (Dallman 1998:27). The remaining stands of Monterey pine are threatened by numerous factors including urbanization, recreational development, and fire suppression, pests and diseases. Fire suppression has resulted in very old stands of forest, which are more susceptible to attacks from pests and diseases. In the Monterey area, the trees are seriously threatened by an epidemic of “pine pitch canker”, a fungal disease caused by Fusarium subglutans pini. This fungus was recently introduced to California from the southeastern United States and is carried from tree to tree by several native insects including the Monterey pine cone beetle (Conophthorus radiatae), twig beetles (Pitophthorus spp.) and engraver beetles (Ips spp.). Indigenous stands of Monterey pine are also threatened by genetic contamination, which results from crossbreeding with planted trees that were brought in from other areas.
Insignias pine, radiata pine, Cambria pine
Regularity: Regularly occurring
Regularity: Regularly occurring
Global Range: Occurs natively in a small area of California (Monterey Peninsula) and on two islands offshore of Baja California, Mexico. Widely cultivated, and often escaped, in other areas of the world, especially in the Southern Hemisphere.
State - Kerala, District/s: Idukki"
California in three disjunct populations in San Mateo and Santa Cruz
counties, Monterey County, and San Luis Obispo County. Pinus radiata
var. binata occurs on Guadalupe Island, Mexico [12,32,33,35,42]. Pinus
radiata var. cedrosensis is found on Cedros Island, Mexico [10,12,38].
Monterey pine is cultivated for timber in Maui, Hawaii . It is also
widely planted for timber in Australia, New Zealand, South Africa,
Chile, Spain, and the British Isles [33,35,41,46,51].
Regional Distribution in the Western United States
This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):
3 Southern Pacific Border
Occurrence in North America
The area occupied by natural stands of Monterey pine on the United States mainland was once well defined, even though estimates of the total area ranged from 4860 to 6480 ha (12,000 to 16,000 acres) (28). Precise natural limits, however, are now difficult to determine because of conspicuous amounts of new regeneration. The southern part of the forest at Año Nuevo, for example, is estimated to have increased by as much as 95 ha (235 acres) in recent decades (14). Additional trees have been planted, and these also have produced seed that led to many acres of new reproduction. Nevertheless, the total area currently occupied probably is no more than 8000 ha (19,770 acres) (21).
- The native range of Monterey pine.
Monterey pines are adapted to soils of medium to heavy texture. Monterey pines have serotinous cones that do not release the seeds unless subjected to high temperatures. Superheating may occur on very hot days or during fire events. Because hot days do not often occur in the Central Coast of California, replenishment of the seed bank is highly dependant on fire (Hillyard 1997).
49.5 to 115.5 feet (15-35 m) and a d.b.h. of 24 to 36 inches (60-90 cm)
. The outer bark is narrowly ridged and the inner bark is resinous
[33,43]. The needles occur in clusters of three and are 4 to 6 inches
(10-15 cm) long. They persist for approximately 3 years [11,33,43].
Cones are 3 to 5.5 inches (7.5-14 cm) long and occur in one or more
clusters of three to five around the branch [16,33,43,54]. Monterey
pine lives a maximum of 80 to 90 years .
Monterey pine has a low frost tolerance .
California Montane Chaparral and Woodlands Habitat
This taxon can be found in the California montane chaparral and woodlands, a near coastal ecoregion in Central and Southern California, USA. This ecoregion is disjunctive, with a major element in Southern California and another along the Monterey County coast. The ecoregion encompasses most of the Transverse Range that includes the San Bernardino Mountains; San Gabriel Mountains; portions of the Santa Ynez and San Rafael Mountains; Topatopa Mountains; San Jacinto Mountains; the Tehachapi, Greenhorn, Piute, and Kiavah Mountains that extend roughly northeast-southwest from the southern Sierra Nevada; and the Santa Lucia Range that parallels the coast southward from Monterey Bay to Morro Bay.
The California montane chaparral and woodland ecoregion consists of a complex mosaic of coastal sage scrub, lower chaparral dominated by chamise, upper chaparral dominated by manzanita, desert chaparral, Piñon-juniper woodland, oak woodlands, closed-cone pine forests, yellow pine forests, sugar pine-white fir forests, lodgepole pine forests, and alpine habitats. The prevalence of drought-adapted scrub species in the flora of this ecoregion helps distinguish it from similar communities in the Sierras and other portions of northern California. Many of the shared Sierra Nevadan species typically are adapted to drier habitats in that ecoregion, Jeffrey Pine (Pinus jeffreyi) being a good example.
Oak species are an important component of many chaparral and forest communities throughout the ecoregion. Canyon Live Oak, Interior Live Oak, Tanbark Oak (not a true Quercus species), Engelmann Oak, Golden-cup Oak, and Scrub Oak are some examples. Mixed-conifer forests are found between 1371 to 2896 meters elevation with various combinations and dominance of incense cedar, sugar pine, and white fir, Jeffrey Pine, Ponderosa Pine, and mountain juniper. Subalpine forests consist of groves of Limber Pine (Pinus flexilis), Lodgepole Pine, and Jeffrey Pine. Very old individual trees are commonly observed in these relict subalpine forests. Within this zone are subalpine wet meadows, talus slope herbaceous communities, krumholz woodlands, and a few small aspen groves.
In addition to these general vegetation patterns, this ecoregion is noted for a variety of ecologic islands, communities with specialized conditions that are widely scattered and isolated and typically harbor endemic and relict species. Examples include two localities of Knobcone Pine (Pinus attenuata) on serpentine soils, scattered vernal pools with a number of endemic and relict species, and isolated populations of one of North America’s most diverse cypress floras, including the rare Gowen Cypress (Cupressus goveniana goveniana) restricted to two sites on acidic soils in the northern Santa Lucia Range, Monterey Cypress (Cupressus macrocarpa) found only at two coastal localities near Monterey Bay, and Sargent Cypress (Callitropsis sargentii LR/LC) restricted to serpentine outcrops. Monterey Pine (Pinus radiata) is also restricted to three coastal sites near Monterey Bay.
The ecoregion is also home to a few endemic or near-endemic mammalian vertebrates, such as the White-eared Pocket Mouse (Perognathus alticolus EN), a mammal known only to two disjunct mountain ranges in southern California: San Bernardino Mountains in San Bernardino County (ssp. alticolus), and the Tehachapi Mountains, in Kern, Ventura, and Los Angeles counties. The near-endemic fossorial Agile Kangaroo Rat (Dipodomys agilis) is found in the southern disjunctive unit of the ecoregion, and is known only to the Los Angeles Basin and foothills of San Gabriel and San Bernardino mountains in Ventura, Los Angeles, and Riverside counties north to Santa Barbara County and through the southern Sierra Nevada, including Mount Pinos, Tehachapi and San Gabriel mountains, and northern San Fernando Valley. Non-endemic mammals found in the ecoregion include Botta's Pocket Gopher (Thomomys bottae) and Trowbridge's Shrew (Sorex trowbridgii). Some larger vertebrate predators can be found in the ecoregion, including Puma (Puma concolor), Bobcat (Lynx rufus), Coyote (Canis latrans), and Ringtails (Bassariscus astutus).
The ecoregion boasts five endemic and near-endemic amphibians, largely Plethodontid salamanders. Some specific salamander taxa found here are the endemic Tehachapi Slender Salamander (Batrachoseps stebbinsi VU), known from isolated sites in the Caliente Creek drainage, Piute Mountains, and Kern County, California along with scattered populations in the Tehachapi Mountains to Fort Tejon, Kern County; the near-endemic Blackbelly Slender Salamander (Batrachoseps nigriventris); the Monterey Ensatina (Ensatina eschscholtzii); the Channel Islands Slender Salamander (Batrachoseps pacificus), endemic to a narrow range restricted solely on Anacapa, Santa Cruz, Santa Rosa, and San Miguel islands; and the Arboreal Salamander (Aneides lugubris), found only in California and Baja California. A newt found here is the Coast Range Newt (Taricha torosa). Anuran taxa in the ecoregion include the Foothill Yellow-legged Frog (Rana boylii NT); the Southern Mountain Yellow-legged Frog (Rana muscosa EN), a California endemic occurring in several disjunctive populations; and the Northern Red-legged Frog (Rana aurora).
The California montane chaparral and woodlands ecoregions contains a number of reptiles such as the Coast Horned Lizard (Phrynosoma coronatum), who ranges from Northern California to Baja California. Also found here is the Sagebrush Lizard (Sceloporus graciosus); the Western Fence Lizard (Sceloporus occidentalis); the Southern Alligator Lizard (Elgaria multicarinata); and the Side-blotched Lizard (Uta stansburiana). The Two-striped Garter Snake (Thamnophis hammondii) is a restricted range reptile found near-coastally from Monterey County, California southward to Baja California.
The California Condor once inhabited much of the ecoregion, with the western Transverse Range acting today as a refuge for some of the last wild populations, after considerable conservation efforts, especially in the Los Padres National Forest. The Heermann's Gull (Larus heermanni NT) is found in coastal areas of the ecoregion.
Habitat and Ecology
Comments: Thrives on almost pure sand, sandy loam, gravelly and sandy clays. Rainfall is 330-457 mm, taking place in winter and early spring. Frequent summer fogs. (FAO, 1986)
Closed-cone coniferous forest, cismontane woodland; elevation 25-185m (California Native Plant Society 2001)
The climate where Monterey pine occurs is humid with mild year-round
temperatures. Winters are wet. Rain does not usually fall in July and
August, but tree crowns collect moisture from summer fog moving inland
. On Guadalupe and Cedros islands the climate is mediterranean
Soils in which Monterey pine grows are often deep, sandy loams with a
clay layer 20 to 33 inches (50-80 cm) below the surface. Good sites
have a top layer of organic soil. Soils are generally acidic .
Slopes are typically gentle and often north facing .
Key Plant Community Associations
Monterey pine is part of the coastal closed-cone coniferous woodland
. It is named as a dominant canopy member in the following
Terrestrial natural communities of California 
A vegetation classification system applied to southern California 
Vascular plant communities of California 
The closed cone pines and cypress 
Associated trees not mentioned in distribution and occurrence are Gowen
cypress (Cupressus goveniana var. goveniana), Monterey cypress (C.
macrocarpa), Santa Cruz cypress (C. goveniana var. abramsiana), Tecate
cypress (C. guadalupensis var. forbesii), bishop pine (Pinus muricata),
and Pacific madrone (Arbutus mensiesii) [23,36,50,52]. Understory
associates include woolyleaf manzanita (Arctostaphylos tomentosa),
California huckleberry (Vaccinium ovatum), poison-oak (Toxicodendron
diversiloba), El Dorado bedstraw (Galium californicum), thingrass
(Agrostis diegoensis), and blue wildrye (Elymus glaucus) [23,52].
This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):
FRES28 Western hardwoods
FRES34 Chaparral - mountain shrub
Habitat: Cover Types
This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):
255 California coast live oak
Habitat: Plant Associations
This species is known to occur in association with the following plant community types (as classified by Küchler 1964):
K009 Pine - cypress forest
K030 California oakwoods
Soils and Topography
Monterey pine is found on soils of four orders. Mollisols are the most prominent and include four Haploxerolls (Santa Lucia, Ben Lomond, Catelli, and Baywood soil series) (36) and four Argialbolls (San Simeon, Conception, Watsonville, and Chamise series). Ultisols are next in extent and are represented by an Albaquult (Narlon series). The Entisol order is represented by one soil series, a Xeropsamment (Tangair series), and the Alfisol order by a Palexeralf (Tierra series).
At all three locations-Año Nuevo, Monterey, and Cambria-the soils have a number of similarities. Most soils are deep sandy loams, often derived from marine sediments. A thick accumulation of organic material is common beneath Monterey pine stands on good sites. The 8- to 15-cm (3- to 6-in) layer of organic material stores many times its weight in water and is a modest reservoir for nutrients. Most soils are found on sloping ground and are reasonably well drained, at least down to a clay layer at the 50- to 85-cm (20- to 33-in) depth. The clay layer is of critical importance. Pine roots generally do not extend far into this layer, but many penetrate for a short distance. Such roots have been observed to be well inoculated with mycorrhizae (10). Another common attribute of soils supporting Monterey pine is that soil pH generally is acid, even extremely acid. Acidity often is high at or just above the clay layer. The combination of poor drainage and high acidity seems to enhance mycorrhizal formation. The clay layer, then, intercepts winter rains and forms a reservoir of water that is available for most of the year. Mycorrhizae on roots at or in the clay layer enhance the nutrient- and water-gathering capability of the pines. Of the seven most common mycorrhizal species that colonize the roots of Monterey pine seedlings in nurseries, Rhizopogon rubescens and R. luteolus enhanced height growth and nutrient uptake the most (6).
In general, the topography on which Monterey pine grows is hilly and gently to moderately sloping. With one possible exception in the Santa Lucia Mountains, elevations range from sea level to about 305 m (1,000 ft). At the three mainland elevations, the most extensive stands are found on modest slopes or gently rolling terrain between the ocean and steeper inland hills. The pine is found on north aspects at all locations and shifts from all aspects at Año Nuevo, through presence only in sheltered canyons on south aspects at Monterey, to complete absence on all other aspects at Cambria. On Guadalupe and Cedros Islands, stands are found on gentle to steep slopes at elevational ranges of 300 to 1100 m (980 to 3,610 ft) on Guadalupe, and 275 to 640 m (900 to 2,100 ft) on Cedros (21).
Limitations in habitat at each location probably contribute to the areal extent of the Monterey pine stands. At Año Nuevo, shallow soil near the coast could be limiting. At Monterey, lower rainfall together with differences in soil depth, texture, and location of clay layer could govern distribution. At Cambria, climate and soil mandate a shift from trees to grass and shrubs. Among the three mainland areas, where genetically controlled differences in tolerance to cold have been noted, the tolerance decreases from north to south (16). Recently, analyses of satellite photos taken over several years have shown that the present groves of closed-cone pines "are all at centers of high fog concentrations" (3). For the three mainland areas, the factor limiting the natural range of Monterey pine at its eastern boundary could be fog, but fog does not sufficiently explain the abrupt northern and southern termination of the pines' natural range. Farther south on Guadalupe and Cedros Islands, absence of fog appears to limit the distribution of the species. In spite of these evident limitations, the causes of restrictions on the range of Monterey pine are not clear.
Temperatures tend to be mild, although extremes range from about -5° to 41° C (23° to 106° F). Mean monthly temperatures show a relatively even climate with a difference between the coldest and warmest month of about 6.5° C (12° F) in the range of 9° to 11° C (48° to 52° F) in winter and 16° to 18° C (61° to 64° F) in summer. Mean temperatures during the growing season, February through June, range from 11° to 16° C (52° to 61° F), with maximums of 17° to 24° C (63° to 75° F) (34). Frost-free days number about 300 each year.
Annual precipitation ranges from about 380 to 890 mm (15 to 35 in) and varies from year to year. From December to March, precipitation averages 300 to 510 mm (12 to 20 in), with less than 50 mm (2 in) per month for the remaining months. Rain usually does not fall in July and August. During these months, however, the tree crowns collect moisture from fog that moves inland. Fog drip can amount to as much as 15 mm (0.59 in) per week at higher elevations on the Monterey Peninsula (25). No snow falls in the natural range of Monterey pine. Año Nuevo is the wettest of the three mainland locales; Cambria, the driest; and Monterey, the foggiest (3).
Wind is, at best, a minor climatic influence, averaging only 7.6 km/h (4.7 mi/h) on an annual basis. May is the windiest month, August the least windy (23).
The climate of Guadalupe and Cedros Islands is Mediterranean-like, possibly with less rainfall and greater temperature extremes than for mainland stands. Fog is a critical factor and, on both islands, pine stands are restricted to foggy ridges and windward slopes, or occasionally to the moist slopes of deep canyons. On Cedros Island, fog was most frequent and of maximum concentration where the pines grew, and each pine grove tended to be covered with fog while the desert between was exposed to clear sky (22).
Habitat & Distribution
Monterey pines are ornamental as well as useful. This species is the most widely cultivated pine in the world (Templeton et al. 1997). Monterey pines are also the most widely planted trees for choose-and-cut Christmas tree farms in California. They are excellent shade trees, act as effective wind and sound barriers, and have been used for erosion control.
Be careful to select a proper place to plant these fast growing trees. Monterey pines are the most rapid growing pine of over 90 species that occur in the world (Labadie 1978). Young trees can grow up to 2 meters per year, generally reaching from 12 to 18 meters within 25 years. The trees have an average life span of 80 to 90 years.
These trees require deep, well drained, medium to course textured soils of medium fertility. Trees that are planted on shallow or waterlogged soils may be unstable because of shallow vertical roots. Monterey pines can be damaged or killed in areas where temperatures reach below freezing.
Monterey pines are usually transplanted from containers or bare rootstock grown by commercial nurseries. However, these plants usually come from New Zealand stock. Even though the New Zealand stock originated from California populations, crossbreeding with native populations is considered a threat to the native population’s conservation because of genetic contamination (Cope 1993).
Seed may propagate Monterey pine trees. Handpick mature cones from the trees or from the ground. Air-dry opened cones by spreading them in a sunny, dry place. To open closed cones, drop them into boiling water for 1 to 2 minutes or more, if needed. Remove the seeds from the cones by shaking them out. Although the cones require heat in order to release the seeds, the seeds do not generally require pretreatment in order to germinate. One to three weeks of cold-moist stratification may improve germination, especially for seeds that have been stored (Emery 1988). Monterey pines are not generally propagated by cuttings as, even with bottom heat, the cuttings may take four or more months to form roots.
thinly subiculate apothecium of Arachnopeziza obtusipila is saprobic on dead twig of Pinus radiata
Remarks: season: 11-3
In Great Britain and/or Ireland:
Foodplant / saprobe
fruitbody of Basidiodendron pini is saprobic on dead, decayed wood of Pinus radiata
Fungus / saprobe
erumpent pycnidium of Camarosporium coelomycetous anamorph of Camarosporium pini is saprobic on fallen cone of Pinus radiata
Foodplant / saprobe
erumpent, solitary apothecium of Cistella acuum is saprobic on dead, especially still attached to cut off branches needle of Pinus radiata
Remarks: season: 9-3
Foodplant / saprobe
superficial perithecium of Coniochaeta malacotricha is saprobic on dead branch of Pinus radiata
Remarks: season: 3-6
Fungus / saprobe
subepidermal, then exposed apothecium of Cyclaneusma minus is saprobic on fallen needle of Pinus radiata
Remarks: season: 11-5
Foodplant / saprobe
colony of Dendrodochium anamorph of Dendrodochium citrinum is saprobic on dead cone of Pinus radiata
Remarks: season: 8-4
Other: minor host/prey
Foodplant / saprobe
apothecium of Dennisiodiscus pinicola is saprobic on cone of Pinus radiata
Remarks: season: 10-11
Other: minor host/prey
Foodplant / saprobe
fruitbody of Diplomitoporus flavescens is saprobic on fallen, dead trunk of Pinus radiata
Foodplant / saprobe
fruitbody of Exidia saccharina is saprobic on dead, fallen branch of Pinus radiata
Foodplant / saprobe
fruitbody of Exidiopsis effusa is saprobic on dead, decayed wood of Pinus radiata
Other: minor host/prey
Foodplant / pathogen
Brunchorstia anamorph of Gremmeniella abietina infects and damages live twig of Pinus radiata
Foodplant / saprobe
apothecium of Hyaloscypha aureliella is saprobic on wood of Pinus radiata
Remarks: season: 7-11
Foodplant / saprobe
erumpent, often clustered apothecium of Lachnellula subtilissima is saprobic on fallen twig of Pinus radiata
Remarks: season: 1-7
Foodplant / saprobe
thyriothecium of Lichenopeltella pinophylla is saprobic on dead, fallen needle of Pinus radiata
Remarks: season: 2-7
Foodplant / saprobe
thyriothecium of Microthyrium pinophyllum is saprobic on decaying needle of Pinus radiata
Remarks: season: 2-4
Foodplant / saprobe
toadstool of Mycena seynesii is saprobic on dead, fallen, decayed cone of Pinus radiata
Foodplant / pathogen
Dothistroma coelomycetous anamorph of Mycosphaerella pini infects and damages live needle of Pinus radiata
Foodplant / saprobe
stromatic, in large groups perithecium of Nectria fuckeliana is saprobic on dead twig of Pinus radiata
Remarks: season: 3-5, 9-12
Foodplant / saprobe
apothecium of Orbilia xanthostigma is saprobic on decorticate wood of Pinus radiata
Remarks: season: 1-12
Other: minor host/prey
Foodplant / parasite
fruitbody of Phellinus pini parasitises live trunk of Pinus radiata
Other: minor host/prey
Foodplant / mycorrhiza / ectomycorrhiza
fruitbody of Russula insignis is ectomycorrhizal with live root of Pinus radiata
Remarks: Other: uncertain
Other: minor host/prey
Foodplant / pathogen
erumpent pycnidium of Sphaeropsis coelomycetous anamorph of Sphaeropsis sapinea infects and damages live cone of Pinus radiata
Remarks: season: 10-4
Foodplant / saprobe
pycnidium of Sirothyriella coelomycetous anamorph of Stomiopeltis pinastri is saprobic on dead, fallen, rotting needle of Pinus radiata
Foodplant / secondary infection
erumpent pycnidium of Sclerophoma coelomycetous anamorph of Sydowia polyspora secondarily infects gall-midge infected needle of Pinus radiata
Foodplant / saprobe
fruitbody of Trechispora clancularis is saprobic on dead, decayed litter of Pinus radiata
Foodplant / saprobe
Tubulicrinis accedens is saprobic on dead, decayed wood of Pinus radiata
Foodplant / saprobe
Tubulicrinis chaetophorus is saprobic on dead, decayed wood of Pinus radiata
Foodplant / saprobe
Tubulicrinis subulatus is saprobic on dead, decayed wood of Pinus radiata
Other: minor host/prey
Associated Forest Cover
The fossil record, although somewhat limited, indicates that this pine once occupied a larger range during the late Pleistocene epoch, extending almost continuously along the outer coastal strip and California islands. Fossil remains have been found at Tomales Bay, Little Sur, Carpinteria, Rancho La Brea, and Santa Cruz Island. The evidence suggests that present-day pines are survivors of an ancient oak-laurel, pine, and palm forest that grew well in a mild climate (2).
Fire is a major influence affecting the extent and makeup of Monterey pine stands. Fire is frequent, sometimes of natural causes, often accidental, and sometimes deliberately set. Graziers at Cambria, for example, burned the woods to obtain more grass. At Año Nuevo, frequent fires have helped to maintain the pine forest. Without fire, the taller and longer-lived coast Douglas-fir (Pseudotsuga menziesii var. menziesii) would usurp land occupied by pines. Much regeneration and a number of even-aged stands at all three mainland locations can be traced directly to the influence of fire.
Many of the plant species associated with Monterey pine have been listed (32). Such lists are subject to change because undisturbed stands are scarce; nearly all have been grazed, burned, or logged.
At Año Nuevo, tree associates of Monterey pine are coast Douglas-fir, redwood (Sequoia sempervirens), knobcone pine (Pinus attenuata), ponderosa pine (P. ponderosa var. ponderosa), coast live oak (Quercus agrifolia), and Pacific madrone (Arbutus menziesii). Some portions of the Monterey pine forest are pure and almost fully stocked with 370 to 740 trees per hectare (150 to 300/acre). Width of tree crowns varies with age, but rarely are crowns interlocking. Monterey pine also intermingles with Douglas-fir on middle slopes and with knobcone pine and an occasional ponderosa pine on upper drier slopes, especially where the soil is shallow and rocky. On lower slopes, redwood and an occasional madrone are present. Coast live oak, usually in the understory, also is an associate species. In some places, natural regeneration of Monterey pine is prominent, particularly where disturbance has bared the soil.
Understory associates generally are not particularly diverse nor abundant at Año Nuevo. In places, however, understory vegetation fully occupies the ground. In addition to young coast live oak, the most common species are bracken (Pteridium aquilinum), poison-oak (Toxicodendron diversilobum), coyotebrush (Baccharis pilularis), blueblossom (Ceanothus thyrsiflorus), California buckthorn (Rhamnus californica), blackberry (Rubus spp.), coast sagebrush (Artemisia californica), and several grasses.
At Monterey, tree associates are coast live oak, Monterey cypress (Cupressus macrocarpa), Gowen cypress (C. goveniana), and bishop pine (Pinus muricata). Coast live oak is the most common tree associate of Monterey pine. Seldom taller than 9 m (30 ft), the oak usually is relegated to the understory. White alder (Alnus rhombifolia) and a species of willow (Salix sp.) are occasional associates in riparian zones. At least one species of willow is scattered throughout the forest on higher ground.
Shrubs and forbs in the Monterey forest vary with time after disturbance and general quality of the habitat. Successionally, young stands of pines, shrubs, and forbs often become established after fire.
At age 45, Monterey pine has a stand density of 160 to 200 trees per hectare (65 to 81/acre). Shaggy-bark manzanita (Arctostaphylos tomentosa) and California huckleberry (Vaccinium ovatum) are prominent with an average cover of about 50 percent. By the time Monterey pine reaches age 65, competition, disease, and slow growth reduce its density to 80 to 120 trees per hectare (32 to 49/acre). In stands of this age, poison-oak, bush monkeyflower (Mimulus aurantiacus) and California blackberry (Rubus ursinus) are present and, along with the shrubs mentioned earlier, contribute to a shrub cover of about 40 percent. Openings form in the pine stand as the trees grow older but density remains about as before because younger age classes of pines contribute. Shrub cover continues at about 40 percent with poison-oak and creeping snowberry (Symphoricarpos mollis) becoming the understory dominants. In old stands where tree diameters are over 100 cm (39 in), one or more age classes of pine are present. Coast live oak sometimes constitutes 25 to 50 percent of the trees in such stands (37).
At Cambria, tree associates of Monterey pine are limited to one hardwood: coast live oak. On better sites, understory vegetation near the typically open pine stands includes coast live oak, bracken, California blackberry, and poison-oak. On drier sites, coast sagebrush, coyotebrush, and bush monkeyflower are present. At the edge of the pine's natural range, grasses often are the only understory plants.
On Guadalupe and Cedros Islands, vegetation associated with Monterey pine is poorly known. That reported for Guadalupe Island is island live oak (Quercus tomentella), Guadalupe Island palm (Erythea edulis), and grasses; for Cedros, bishop pine, yucca (Yucca spp.), and at least two species of cactus (Opuntia spp.).
Diseases and Parasites
Fire is a particular hazard to young, thin-barked trees and can be disastrous in dense plantations where persistent lower limbs become festooned with dead needles, resulting in an ideal situation for crowning fires. Pruning to a height of 2.1 to 2.4 m (7 to 8 ft) helps keep a fire on the ground and is a desirable measure for protection (32).
Pathogens of significance in the natural range of Monterey pine include a dwarf mistletoe, two gall rusts, and two root diseases. Digger pine dwarf mistletoe (Arceuthobium occidentale) infects trees of all ages and is found in native stands except at Aho Nuevo (32). Western gall rust (Peridermium harknessii) and coastal gall rust (P. cerebroides) are found in the three stands in the United States and cause significant damage to young trees. Cedros and Guadalupe Island populations of Monterey pine have higher resistance to western gall rust than mainland populations (29). A widespread pathogen of particular virulence is annosus root disease (Heterobasidion annosum). Armillaria root disease (Armillaria mellea) is found where oaks are present, but damage to Monterey pine is minor.
Outside its natural range, Monterey pine is attacked by several pathogens in addition to those in native stands. Of these, the red band needle blight (Scirrhia pini) is the most damaging. This worldwide pathogen is not found in native stands but has caused serious damage and is a major concern for plantations in British Columbia, Washington, Oregon, and north-coastal California. Western gall rust is a pest in plantations from central California to British Columbia and can be damaging to Christmas tree plantations. As many as 35 other pathogens cause negligible to minor damage in exotic stands of Monterey pine (5,32).
Furniss and Carolin (12) list 56 insects from 44 genera that feed on Monterey pine foliage, twigs, branches, and boles. Relatively few of these cause significant damage and only five can kill trees, especially those weakened by other agents. Four are bark beetles and one is a weevil; all are cambium feeders.
Bark beetle larvae mine the cambium of all but young trees. Once the trunk is girdled, the tree dies. All four species produce broods in stumps or fresh cut limbs and logs and commonly work in concert on individual trees. The Monterey pine ips (Ips mexicanus) is seldom a primary killer except in young plantations. The California four-spined ips (I. plastographus) and pinyon ips (I. confusus) attack large and small trees. The red turpentine beetle (Dendroctonus valens) killslarge, mature trees.
The Monterey pine weevil (Pissodes radiatae) is primarily a threat to young trees where the larvae mine cambium in tops, stems, bases, and even portions below ground.
Various other insects, including aphids, borers, caterpillars, and moths, cause minor damage. Probably the most serious of these is the Monterey pine cone beetle (Conophthorus radiatae) that attacks maturing cones in central California but does not damage the more southerly population.
Animal damage to ornamental plantings can be a problem but generally is not serious. On Guadalupe Island, however, chronic overgrazing by goats has virtually eliminated Monterey pine regeneration.
Fire Management Considerations
of flammable fuels . Crown scorch and cambium damage are reduced
when slash is mechanically reduced before burning .
Plant Response to Fire
Monterey pine cones open and release seed after fire . In
California, White [in 52] reported a seedling density of 196 per acre
(490/ha) the January following a spring wildfire. Seedlings were 12 to
22.4 inches (30-56 cm) tall.
Immediate Effect of Fire
Monterey pine is killed by severe surface or crown fire. Trees survive
crown scorch unless it is extensive. In South Africa Monterey pine
survived a surface wildfire except where crown scorch was greater than
90 percent [13,14]. Trees are damaged by direct heat. Exposure to a
temperature of 424 degrees Fahrenheit (200 deg C) for more than half a
minute resulted in cambium death wherever heat was applied [13,52].
Such localized burning or scorching of bark of mature trees causes
scarring but may not result in tree death .
Young, thin-barked Monterey pine are often killed by fire, particularly
when stands are dense and crown fire occurs .
Tree without adventitious-bud root crown
Crown residual colonizer (on-site, initial community)
Monterey pine cones are serotinous; seeds are released when cones are
exposed to heat such as fire or high air temperature [19,31,37,53].
Fire is particularly effective for opening cones and releasing seeds.
It also creates a favorable seedbed. Reproduction rates are greatest
after surface fire in which the parent trees survive .
The foliage of Monterey pine is low in volatile terpenes .
Facultative Seral Species
Monterey pine normally invades dry sites with poor, shallow soils. It
also invades oldfields after land clearance, grazing, fire, or logging
. Trees establish in even-aged stands .
Monterey pine has intermediate shade tolerance [6,35]. As it matures it
becomes even less tolerant of shade, and shows optimal growth in full
years. Maximum seed production beings at 15 or 20 years of age if trees
are open-grown, and later if stands are dense [11,25,35]. Cones are
produced annually, with good cone crops produced every other year .
Mature cones remain attached to the branch. They may remain closed for
several years, depending upon temperature and humidity. Cones open and
release seed during warm, dry periods and close rapidly when temperature
drops and relative humidity increases. This results in a constant but
meager seed rain . The cones of native populations open
infrequently because their habitat is typically cool and moist.
Seedfall is heaviest in warm, dry years . Unreleased seed remains
viable for decades. Seeds from cones up to 24 years of age have
germinated; however, germinative capacity appears to fall off with
progressing years . Seeds can be exposed to a temperature of 203
degrees Fahrenheit (95 deg C) before germination is significantly
reduced . Seedling recruitment is best on mineral soil .
Details of growth are discussed in the literature .
Monterey pine does not reproduce by sprouting [14,35].
Growth Form (according to Raunkiær Life-form classification)
Reaction to Competition
The species is regarded as moderately windfirm on deeper soils but less so on shallow soils. Trees growing in soils saturated with moisture are vulnerable to windthrow, particularly in exposed places (24).
Life History and Behavior
Pollination occurs from January to February but may be extended due to
high temperatures [15,25,35]. Cones open and seeds are dispersed in the
first warm, moist days of late winter and early spring. Cones may open
and close several times as moisture and temperature conditions fluctuate
Reproduction from artificially rooted propagules of this pine has been successful in many trials in several countries. Hedging is one method for successfully mass-producing large numbers of symmetrical and straight cuttings and maintaining the juvenile nature of propagules (22). Plantlets from embryos and cotyledons are another (1).
Cuttings, or other means of vegetative propagation, offer a number of advantages over seedlings, not the least of which is closer control of genotype. Cuttings from mature planting stock show a reduced incidence of retarded leaders, excessive branching, crooked internodes, and frost susceptibility. Vegetative propagules also tend to have straighter boles, less forking, fewer and smaller branches, less bole taper, and thinner bark (22). Height growth of cuttings generally is similar to that of seedlings, although extremes of environment and age of ortet can cause lower growth than from seedlings. Cuttings also develop a higher frequency of cones on the bole-a negative factor. This can be mitigated by pruning, however.
Germination is epigeal New germinants bear a whorl of five to nine cotyledons that are succeeded by primary needles. Secondary needles in fascicle bundles form when the seedling is a few months old. After age 3, the seedling produces only secondary needles. The root system of most seedlings consists of a slender taproot, aimed straight down.
Mycorrhizal associations with root tips in the upper 10 cm (4 in) of soil probably increase nutrient and water intake and enhance the growth of Monterey pine seedlings. At least 16 mycorrhizal fungi associated with Monterey pine have been identified in the United States and several others noted in other countries (28).
The seedbed required for natural regeneration of Monterey pine is highly variable. The best seedbed is moist mineral soil free of competing vegetation. Numerous seedlings, however, are found where the seedbed consists of several inches of pine needles over mineral soil (23). Although unknown, these seedlings could be the survivors of a great many seedlings and they could be much older than similar-sized, free-to-grow counterparts on bare mineral soil.
Seedlings develop best in full sunlight. Soil disturbed by logging and fire is conducive to seedling establishment and rapid growth. Dense slash decreases seedling density, although light slash can improve the seedling "catch."
Optimum conditions for regeneration, however, are produced by fire; maximum numbers of cones are opened, and at least a temporarily competition-free and receptive seedbed is prepared (37). As a result, dense stands often are formed after burning. In fire-killed stands in foreign countries, Monterey pine seedlings were reported to number 1,235,500/ha (500,000/acre) and more than 2,471,000/ha (1,000,000/acre) (32).
On Guadalupe Island, seedlings and saplings are scarce. "Very dense reproduction," however, was recorded in places on Cedros Island (21).
Pines also become established in grassland vegetation and beneath live oaks, the latter providing shade during the critical establishment period. In most instances, the pines eventually grow through the oak canopy and dominate (23). Some pines reproduce naturally under the canopies of older trees. Number and vigor of pine seedlings and saplings relate directly to the spacing of the older trees; the more dense the overstory, the fewer and slower growing the seedlings. Dense thickets often are formed in small openings.
Naturally established Monterey pine seedlings are fairly large initially and grow larger quickly. Seedlings 30 to 56 cm (12 to 22 in) tall after one growing season are common. Rapid shoot growth usually starts in February and continues until September. Monterey pine apparently begins growth at colder soil temperatures than associated conifers. Lack of soil moisture limits growth in the fall. The period of growth is variable, differing from tree to tree and from season to season (23). By age 5, trees are about 6.6 cm (2.6 in) in d.b.h. and 6 m (20 ft) tall (19). By this age, seedling roots have expanded much more laterally than vertically and have formed a lateral, rather than a taproot, system.
Artificial regeneration of Monterey pine in California is usually for horticultural rather than timber-growing purposes; however, several large plantations have been established for a variety of reasons. The most successful and long-lasting plantations are in central California near the Pacific Ocean (28).
Monterey pine grows readily in California nurseries. Its only problem is rapid growth and stock too large for field planting. At one nursery, average seedling height was 41 cm (16 in), accumulating from the normal seeding date in April to lifting in January.
Seedling size and growth are affected by seed size, soil temperature, and soil moisture. After 32 weeks, Monterey pine seedlings were taller and heavier from seeds retained by a 0.39 cm (0.15 in) mesh screen than from seeds passing through a 0.33 cm (0.13 in) screen (13).
Seedling root growth was greatest at 15° C (59° F), a value 5° C (9° F) lower than the optimum soil temperature reported for other pines. Monterey pines with a predawn water potential of -1.5 MPa (-15 bars) were unable to open stomates, a phenomenon also noted at a similar value for ponderosa and lodgepole (Pinus contorta) pines (17).
Seed Production and Dissemination
Cones remain attached to the trees for many years and open and close several times, depending on temperature and humidity. Because the habitat of the species is typically cool and moist, cone opening is infrequent and of short duration, so that seeds are often retained and then disseminated over a longer period than in warmer and drier climates.
Although cones and seeds are produced almost every year, seedfall varies. A relatively small number of seeds dribble out of the cones each year. In warm and dry years, seedfall can be heavy. Fire is particularly effective for opening cones and releasing large quantities of stored seeds.
Several species of birds and small mammals depend in part for sustenance on the seeds of Monterey pine. Principal bird species are the scrub jay, Stellar jay, and common crow. Important small mammals are deer mice, chipmunks, and ground squirrels (7). Numerous other creatures eat the seeds of this pine, but their effect usually is insignificant.
Flowering and Fruiting
Growth and Yield
Branches of Monterey pine saplings die when shaded but persist on the bole for many years. In dense stands, the trunks clean themselves well (35). Mature trees often have clear boles for 8 to 15 m (26 to 49 ft).
Height growth of pole-sized trees on poor sites may slow down appreciably after 15 years, but on better sites, it continues at a good rate until trees are about age 50 (19). At Monterey, pole-sized trees less than 30 cm (12 in) in d.b.h. average about 20 years old and 20 m (64 ft) tall. Height of mature trees ranges from 9 to 38 m (30 to 125 ft) but generally is 21 to 30 m (69 to 98 ft), with the tallest trees often found in small gullies. Diameters vary widely and, on a good site, average just under 64 cm (25 in) in d.b.h. A few trees reach an exceptional diameter of 122 cm (48 in) in d.b.h. At Cambria, Monterey pines are a little taller, averaging 30 to 37 m (98 to 121 ft) at maturity (23).
On Guadalupe Island, the tallest tree was 33 m (108 ft); the largest d.b.h. recorded was 211 cm (83 in). On Cedros Island, the tallest tree measured 32 m (105 ft); the tree with the largest d.b.h. was 77 cm (30 in) (21).
Crown development of Monterey pine is a function of age and spacing. In crowded conditions, the species has a narrow pointed crown. Vigorous trees continue to have pointed crowns until 35 to 45 years of age, after which the crown becomes flat and irregular. Trees 30 to 46 cm (12 to 18 in) in, d.b.h. have crowns 5 to 6 m (16 to 20 ft) wide, but much narrower if crowded, and those larger than 76 cm (30 in) in d.b.h. have crowns 9 to 12 m (30 to 39 ft) wide. Trees taller than 30 m (98 ft) have a live crown one-third to one-sixth of this length (23).
Monterey pine is short lived. It attains full size in 80 to 100 years and rarely lives beyond 150 years (35).
Yield of Monterey pine in natural stands is lowered by the characteristically open spacing of the trees. Pine volume averages less than 281 m³/ha (4,011 ft³/acre). As stocking increases, so does productivity. A stand with better than average stocking, for example, averaged 490 m³/ha (7,003 ft³/acre). Trees were about 50 years old, 39 cm (15 in) in d.b.h., and numbered 408/ha (165/acre). The best stocked stand at Monterey contained 482 trees and 1681 m³/ha (195 trees and 24,009 ft³/acre). These trees averaged 52 cm (20 in) in d.b.h. and 29 m (95 ft) in height (19).
In other countries, the yield of Monterey pine in plantations that are thinned and pruned and sometimes fertilized is much higher than that of natural stands. In New Zealand, stands 35 to 40 years old yield about 770 m³/ha (11,004 ft³/acre). On a productive site in Chile, trees 20 years old produce about 500 m³/ha (7,145 ft³/acre). They number about 270 trees per hectare (109/acre) after three thinnings, average about 48 cm (19 in) in d.b.h., and have been pruned three times (30).
Molecular Biology and Genetics
Hybrids No evidence of widespread introgression from knobcone or bishop pine has been found, although hybridization is occurring locally between Monterey and knobcone pines at Año Nuevo (11). The hybrid is designated Pinus attenuata x radiata Stockwell & Righter. The two-needled pine found on Guadalupe and Cedros Islands is currently named P. radiata var. binata.
The unique characteristics of rapid growth, large genetic variability, and ease of vegetative propagation have made Monterey pine the subject of intensive genetic improvement programs in several countries, notably Australia and New Zealand.
Barcode data: Pinus radiata
Statistics of barcoding coverage: Pinus radiata
Public Records: 7
Specimens with Barcodes: 24
Species With Barcodes: 1
IUCN Red List Assessment
Red List Category
Red List Criteria
Based on the assessments of the two varieties, it is considered that although the large subpopulation on Cedros Island (var. binata) appears stable, the situation on the mainland (var. radiata) is more severe and in total the population is in continuing decline. There are no more than five locations and the population is severely fragmented. With a combined area of occupancy of less than 30 km² the species meets B2 for Endangered.
National NatureServe Conservation Status
Rounded National Status Rank: N1 - Critically Imperiled
Rounded National Status Rank: N1 - Critically Imperiled
NatureServe Conservation Status
Rounded Global Status Rank: G1 - Critically Imperiled
Reasons: Five natural populations of the species are known: Three on the coast of Califonia in the USA, and two island populations off the coast of Baja California in Mexico (Food and Agriculture Organization 1986). The Guadalupe Island population is becoming extinct due to grazing of seedlings by goats, with all regeneration there effectively precluded. Monterey and Cambria populations are threatened by urbanization. The Cedros Island and ANuevo populations are not presently endangered. Occurs naturally in foggy areas. The timber is highly regarded and plantations have been established in a number of countries (Food and Agriculture Organization 1986). The tree prefers to grow on slopes, in coarse soils, usually sandy loams, and is often found in pure stands (Tree Talk 1994).
United States and Canada is available at NatureServe.
The California Native Plant Society considers Monterey pine rare in its native range. Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status (e.g. threatened or endangered species, state noxious status, and wetland indicator values).
Comments: Threatened by development, genetic contamination, pine pitch canker disease, forest fragmentation, and feral goats (California Native Plant Society 2001). Also threatened by invasive exotic plants and past logging and fire suppression.
Pests and potential problems
Western dwarf mistletoe, western gall rust, various needle blights, pitch moth, red turpentine beetle, pitch canker, Monterey pine scale, irregular pine scale, pine leaf scale, aphids, mites, pine tip borer, pine tip moth.
Cone processing and nursery practices are discussed in the literature
Monterey pine is affected by many pests such as western dwarf mistletoe,
western gall rust, various needle blights, and moths [2,35,44].
Monterey pine is moderately windfirm on deep soils .
Goats have nearly eradicated all natural regeneration of Montery pine on
Gudalupe Island [27,35].
Much of the Monterey pine planted as ornamentals comes from New Zealand
stock. This stock originated from native California populations several
generations ago. In Cambria and Monterey, California, this imported
stock is crossbreeding with native individuals. The genetic effects of
this crossbreeding on native trees is unknown, and preserving genotypes
of native individuals is a point of management concern . Monterey
pine is the subject of a genetic conservation program .
Cultivars, improved and selected materials (and area of origin)
These plants are readily available from commercial sources. Request plants established from native California rather than New Zealand stock. If you are planting trees in areas near native stands, be sure the seeds or seedlings are from the same genetic stock as those stands.
Contact your local Natural Resources Conservation Service (formerly Soil Conservation Service) office for more information. Look in the phone book under ”United States Government.” The Natural Resources Conservation Service will be listed under the subheading “Department of Agriculture.”
Although Monterey pines are threatened in their present native habitat, they have been considered a weedy pest in some areas of California where they have escaped cultivation. Millar (1998) uses fossil evidence to support an alternate view: that Monterey pine populations have historically shifted in size and location along the California and Baja coasts in response to changing climate. She suggests, that in order to allow for the continued survival of Monterey pines, establishment of new stands of native stock within the pine’s historical range should be considered as opportunities for their conservation and not as a threat to other native species.
Established trees require occasional deep watering accompanied by a light fertilization to remain healthy. To control the size of the tree, and to increase bushiness, the new growth, called candles, may be pruned in the spring as they appear. Remove dead or dying branches.
This plant may become weedy or invasive in some regions or habitats and may displace desirable vegetation if not properly managed. Please consult with your local NRCS Field Office, Cooperative Extension Service office, or state natural resource or agriculture department regarding its status and use. Weed information is also available from the PLANTS Web site.
Relevance to Humans and Ecosystems
Uses: FIBER, Building materials/timber
Comments: Fast growing trees produce wood of excellent commercial quality. Wood variously used for pulp, plywood, building and packaging materials (Food and Agriculture Organization 1986). The species is cultivated on a commercial scale in New Zealand, Australia, Chile and South Africa (Tree Talk 1994).
Other uses and values
provides a barrier to wind and noise [35,53]. It is also used for
Christmas trees .
Wood Products Value
little commercial value in the United States except as fuelwood .
In other parts of the world it is used for general construction,
flooring, furniture, joinery, plywood, reconstituted panel products, and
paper. When treated with preservatives it cab be used for siding,
decking, external trim, poles, piles, fencing, and railroad ties .
Value for rehabilitation of disturbed sites
establishment and a widespreading root system make it a good species for
stabilizing soils on steep slopes .
Importance to Livestock and Wildlife
also eat the bark [27,30,35]. Birds and small mammals consume the seeds
A major use of this pine is as an ornamental in parks and urban areas. The species often is planted in areas devoid of trees where its rapid growth and attractive foliage quickly provide variety and contrast to the landscape. The pine also is planted extensively to help establish vegetative control of eroding and blowing soils. Prized as a living screen against wind, noise, and traffic, Monterey pine graces many a boulevard and backyard in urban areas. It also has been asexually propagated for Christmas trees (33).
In its native habitat and particularly near the ocean, the rugged, picturesque, wind-battered trees deserve special mention for their esthetic appeal. Stands near Carmel, CA, are among the most photographed in the world.
Ethnobotanic: The seeds of all pine species are edible and pine nuts have historically been an important food utilized by many Native American tribes (Strike 1994). Pines were also valued for their wood, sap, and pine needles. Because of its restricted range, few tribes used Monterey pine. The Costanoan and probably the Salinan relied on the seeds as a source of food in coastal areas of their territory. Pedro Fages (1937) describes the California Indians in the Monterey area as using many kinds of pine nuts and among them those of Monterey pine. He writes, “the cones of the pine tree are small, and the nuts are extremely so, but very good and pleasing to the taste. The method of gathering them is to build a fire at the foot of the tree, which in a few hours falls, making the fruit available without difficulty” (Fages 1937; 68-69). Many bedrock mortars are found adjacent to Monterey pine forests, which may be additional evidence of their use by both tribes (Leonard 1963). The closed cones of Monterey pines were probably a particularly valuable resource because they remain on the tree and can therefore be harvested all through the year. The closed cones open in response to heat and could be easily opened by placing them on or near a fire. Pine nuts were eaten whole or pounded into flour that was made into porridge or mixed with other foods. The young, male catkins are edible and said to have a nice flavor either raw or cooked (Couplan 1998). During heavy winters or times of scarcity the inner bark of pine trees would serve as an emergency food.
The needles of pines, which contain vitamin C, were brewed into a tea that was drunk to treat headaches (Heinsen 1972). The Costanoan and others chewed pine resin to treat rheumatism. This resin or pitch was used as a salve that was applied to burns and sores. Pine resins were useful as glue or sealant. Pine resin was also chewed as gum. Pine nuts were burned into charcoal, crushed, and then applied to both sores and burns. Various Native American tribes used the split roots of many pine species as the foundation to make fish traps, seed beaters, burden and many other types of baskets (Murphey 1959). The inner portions of slender new pine twigs could be processed into sewing materials (Barrett & Gifford 1933).
Livestock: Goats browse on Monterey pines.
Wildlife: Black-tailed deer browse the leaves and branches of Monterey pine. Porcupines are known to browse on leaves and branches as well as eat the bark. Small mammals including deer mice, chipmunks, and ground squirrels eat the seeds. Among the birds that eat the seeds are scrub jays, Stellar jays, and crows. Nesting chestnut-backed chickadees have been observed to obtain almost 80% of their insect diet from foraging in Monterey pine trees (Kleintjes & Dahlsten 1994).
Other: Monterey pine is used for erosion control and stabilization of steep slopes because it is fast growing and has a wide spreading root system. The trees are sometimes used as Christmas trees.
Pinus radiata is a versatile, fast-growing, medium-density softwood, suitable for a wide range of uses. Its silviculture is highly developed, and is built on a firm foundation of over a century of research, observation and practice. Radiata pine is often considered a model for growers of other plantation species. It is the most widely planted pine in the world, valued for rapid growth and desirable lumber and pulp qualities.
It is native to three very limited areas located in Santa Cruz, Monterey Peninsula, 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./subsp. 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 and in Argentina, Chile, Uruguay, Kenya, and South Africa it is a major plantation species.
Pinus radiata is a coniferous evergreen tree growing 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 moderately 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 firewood, but the modern product is very different.
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.
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. 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.
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.
On Guadalupe Island, var. binata is critically endangered. Most of the population was destroyed as tens of thousands of feral goats ate binata seedlings and caused soil erosion 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. The University of California's Russell Reservation forestry research station hosts an orchard planted with 73 Pinus radiata seedlings from Guadalupe Island and plays an important role in conserving the binata variety.
Australia has large plantations of (though they are less than 2% 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.
P. radiata has greatly replaced the Valdivian temperate rain forests, where vast plantations have been planted for timber, again displacing the native forests. In 2001, this species produced 5,580,724 cubic meters of lumber, or 95% of Chile's total lumber production.
The Monterey pine (always called Pinus radiata in New Zealand) was first introduced into New Zealand in 1859 and today 89% of the country's plantation forests are of this species. 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 or more commonly wilding pine) where it has escaped from plantations. It is the most extensively used wood in New Zealand.
A 1995 change to the New Zealand building regulations no longer required boron treatment of radiata pine to be used for framing houses, a key factor in the subsequent expensive leaky homes crisis. From 2003 onward a series of changes have now improved the regulations.
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.
As timber radiata is suitable for a wide variety of uses. It holds screws and nails well and takes paint and stain without difficulty - and modern kiln dried timber is very easy to work. 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).
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 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. Radiata timber has a resinous fragrance while being worked. 
Lower grade timber is converted to pulp to make newsprint. Higher grade timber is used in house construction. 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 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 resorcinol waterproof glue. Since the 1990s finger jointed joinery-grade wood has become available in up to 6m lengths in a wide range of profiles.
In 1958, New Zealand boat designer Des Townson started building 186 eleven-foot, cold-moulded Zephyr-class yachts, using Pinus radiata. In 2011 these hand-built boats fetched very high prices and were generally in excellent condition.
The bark is also used as a substrate for potting and re-potting orchids.
Pinus radiata is the most common species of Christmas tree in New Zealand.
- Farjon, A. 2013. Pinus radiata. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1. <www.iucnredlist.org>. Downloaded on 13 July 2013.
- "BSBI List 2007" (xls). Botanical Society of Britain and Ireland. Archived from the original on 2015-02-25. Retrieved 2014-10-17.
- 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.
- Mead, D (2013). Sustainable management of Pinus radiata. Rome: Food and Agriculture Organization of the United Nations. ISBN 978-92-5-107634-7.
- Pinus radiata (D. Don 1836), Gymnosperm Database
- "Status of Native Monterey Pine (Pinus radiata) Ecosystems"
- Scott, 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 www.na.fs.fed.us/pubs/silvics_manual/Volume_1/pinus/radiata.htm, Philip M. McDonald and Robert J. Laacke. "Monterey Pine" accessed 2013-09-14
- [Little, Elbert L. Jr. 1980. The Audubon Society field guide to North American trees. New York: Alfred A. Knopf.]
- Hogan, C. Michael; Frankis, Michael P. (2009). "Monterey Cypress (Cupressus macrocarpa)". GlobalTwitcher.com. Retrieved 14 January 2011.
- Hawksworth, F.G. and D. Wiens. 1996. Dwarf mistletoes: Biology, pathology and systematics. Agriculture Handbook 709. Washington, DC: U.S.D.A. Forest Service.
- Monarch Grove Sanctuary
- 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, 13–14 November 2003. HTML abstract
- Rogers, Deborah L. "Status of Conservation of Monterey Pine". University of California Division of Agriculture and Natural Resources, Genetic Resources Conservation Program. Retrieved 17 March 2012.
- "TEMPERATE RAIN FOREST of Chile "
- "...he first NZ introduction of British seedlings in 1859..."
- "Radiata pine", Te Ara
- "Situation and outlook for New Zealand agriculture and forestry" (PDF). NZ Ministry of Agriculture and Forestry. 2007. Retrieved 2010-10-19.
- "Background note: Information briefing for members of Parliament:Leaky buildings". NZ Parliamentary Library. 6 November 2002.
- "Leaky homes will cost $11.3b to fix - report". The New Zealand Herald. 22 December 2009. Retrieved 26 February 2012.
- "Changes to Acceptable Solution B2/AS1 - Timber Durability 23 Dec 2003", archived entry, dbh.govt.nz
- "Radiata pine", Primary Industries and Fisheries, QLD
- "Radiata pine", nzwood.co.nz
- "Annual paper production is now over 300,000 tonnes.", Norske Skog Tasman
- 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)
|Wikimedia Commons has media related to Pinus radiata.|
Pinus radiata is a much better-formed tree and of greater silvicultural value within its introduced range (Africa, Australia, Europe, and New Zealand, where it is a principal timber tree) than in its native range. It hybridizes naturally with P . attenuata ( P . ´ attenuiradiata Stockwell & Righter).
Names and Taxonomy
Comments: By some (e.g., Perry, 1979) considered to include two varieties (var. radiata in California and var. binata in Mexico), but Little (1979), FNA (1993), and Kartesz (1994) do not maintain this distinction.
Guadalupe Island pine
Cedros Island pine
Pinus muricata D. Don var. cedrosensis Howell
D. Don [12,31,32,33,43]. There are three recognized varieties [10,38]:
Pinus radiata var. radiata
Pinus radiata var. binata Lemmon
Pinus radiata var. cedrosensis (Howell) Axelrod.
Monterey pine hybridizes with knobcone pine (Pinus attenuata) and bishop
pine (Pinus muricata) [12,32,25].
EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.
To request an improvement, please leave a comment on the page. Thank you!