Pinaceae -- Pine family

    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

The typical variety of Monterey pine occurs along the coast of
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 [33]. It is also
widely planted for timber in Australia, New Zealand, South Africa,
Chile, Spain, and the British Isles [33,35,41,46,51].

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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

CA HI MEXICO

Native stands of Monterey pine are found in three distinct areas  of central-coastal California in San Mateo, Santa Cruz, Monterey,  and San Luis Obispo Counties. The northernmost stand is east of  point Año Nuevo, the central stand 48 km (30 mi) to the  south near Monterey and Carmel, and the southernmost stand about  105 km (65 mi) away in the Pico Creek-Cambria area (15). Seldom  is the pine found more than 11 km (7 mi) from the sea. The  north-south range is about 209 km (130 mi). A close relative of  Monterey pine also inhabits the northeastern portion of Guadalupe  Island and the northern and central parts of Cedros Island-both  of which are Mexican possessions. Guadalupe Island is 740 km (460  mi) south of Cambria, and Cedros Island is 908 km (564 mi)  south-southeast of Cambria. Although trees on these islands  differ in morphology from those in the United States, they have  now been shown to be most closely related to P. radiata (21).

    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.

Pinus radiata D. Don:
Venezuela (South America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

The typical variety of Monterey Pine occurs along the coast of 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 and Cedros islands, Mexico. Although trees on these islands differ in morphology from those in the United States, they have been shown to be most closely related to P. radiata.

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.

Mexico

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

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.

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).

Trees to 30m; trunk to 0.9m diam., contorted to straight; crown broadly conic, becoming rounded to flattened. Bark gray, deeply V-furrowed, furrow bases red, ridges irregularly elongate-rectangular, their flattened surfaces scaly. Branches level to downcurved or ascending, poorly self-pruning; twigs slender, red-brown, sometimes glaucous, aging gray, rough. Buds ovoid to ovoid-cylindric, red-brown, ca. 1.5cm, resinous. Leaves (2--)3 in a fascicle, spreading-ascending, persisting 3--4 years, (8--)9--15(--20)cm ´ 1.3--1.8(--2)mm, straight, slightly twisted, deep yellow-green, all surfaces with fine stomatal lines, margins serrulate, apex conic-subulate; sheath (1--)1.5--2cm, base persistent. Pollen cones ellipsoid-cylindric, 10--15mm, orange-brown. Seed cones maturing in 2 years, shedding seeds soon thereafter, but often serotinous and persistent 6--20 years, solitary to whorled, spreading to recurved, curved, very asymmetric, ovoid before opening, broadly ovoid when open, 7--14cm, pale red-brown and lustrous, scales rigid, stalks to 1cm; apophyses toward outer cone base increasingly mammillate, those on inward cone side and middle and apex of cone more level; umbo central, mostly depressed, with small central boss or occasionally with slender, deciduous prickle. Seeds compressed-ellipsoid; body ca. 6mm, dark brown; wing 20--30mm. 2 n =24.

Monterey pine is a native, evergreen conifer. It attains a height of
49.5 to 115.5 feet (15-35 m) and a d.b.h. of 24 to 36 inches (60-90 cm)
[43]. 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 [49].

Monterey pine has a low frost tolerance [35].

Tree, Evergreen, Monoecious, Habit erect, Trees without or rarely having knees, Tree with bark rough or scaly, Young shoots 3-dimensional, Buds resinous, Leaves needle-like, Leaves alternate, Needle-like leaf margins finely serrulate (use magnification or slide your finger along the leaf), Leaf apex acute, Leaves > 5 cm long, Leaves < 10 cm long, Leaves yellow-green above, Leaves yellow-green below, Leaves not blue-green, Needle-like leaves triangular, Needle-like leaves twisted, Needle-like leaf habit erect, Needle-like leaves per fascicle mostly 3, Needle-like leaf sheath persistent, Twigs glabrous, Twigs viscid, Twigs not viscid, Twigs without peg-like projections or large fascicles after needles fall, Berry-like cones orange, Woody seed cones > 5 cm long, Seed cones bearing a scarlike umbo, Umbo with missing or very weak prickle, Bracts of seed cone included, Seeds brown, Seeds winged, Seeds unequally winged, Seed wings prominent, Seed wings equal to or broader than body.

Pinus insignis Douglas ex Loudon

More info for the term: tree

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
[35]. On Guadalupe and Cedros islands the climate is mediterranean
[23,35].

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 [35].
Slopes are typically gentle and often north facing [35].

More info for the term: natural

Monterey pine is part of the coastal closed-cone coniferous woodland
[23]. It is named as a dominant canopy member in the following
publications:

Terrestrial natural communities of California [23]
A vegetation classification system applied to southern California [44]
Vascular plant communities of California [50]
The closed cone pines and cypress [52]

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].

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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

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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

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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

In spite of a small and narrow natural range, Monterey pine grows  on soils that are derived from a variety of parent materials. At  Año Nuevo, for example, the underlying rocks are shales  and marine sandstones. At Monterey, these rocks and granite are  present, and at Cambria, parent materials are limestones,  sandstones, cherts, and slates.

    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.

The Monterey pine habitat is strongly influenced by its proximity  to the Pacific Ocean from which the cold waters of  southward-flowing currents result in high humidity, low  temperatures, and summer fogs. The minimum relative humidity at  Monterey in July, for example, averages between 60 and 70 percent  (23). At least one-third of the days each year are foggy (35).

    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).

Coastal fog belt; of conservation concern; 30--400m; Calif.; Mexico in Baja California [600--1200 m].

Habitat and Ecology

Systems

• Terrestrial

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)

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.

Foodplant / saprobe
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

Monterey pine has been listed in at least two vegetation  classifications: the Closed-Cone Pine Forest Community of  California (27) and the Closed-Cone Pine and Cypress Californian  Floristic Province (31).

    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.).

Within its restricted range, few abiotic  factors cause significant damage except pollution, especially  ozone. Because of its rapid growth, Monterey pine has been  planted widely along the western coast of North America. In these  plantings and even in the Central Valley of California, the pine  technically is an introduced species because it is exposed to  environmental conditions rare in its native range. Temperatures  below freezing for only a few hours seriously damage and kill  trees of all ages. Trees that are rapidly growing or newly  planted are susceptible to windthrow during winter storms. Sudden  increases in temperature to 38° C (100° F) or greater  cause needle scorch and damage to new growth (5).

    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.

Thinning and pruning in Monterey pine plantations result in accumulation
of flammable fuels [8]. Crown scorch and cambium damage are reduced
when slash is mechanically reduced before burning [8].

More info for the terms: density, wildfire

Monterey pine cones open and release seed after fire [19]. 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.

More info for the terms: crown fire, tree, wildfire

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 [52].

Young, thin-barked Monterey pine are often killed by fire, particularly
when stands are dense and crown fire occurs [52].

More info for the terms: crown residual colonizer, root crown

Tree without adventitious-bud root crown
Crown residual colonizer (on-site, initial community)

More info for the terms: serotinous, surface fire

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 [52].

The foliage of Monterey pine is low in volatile terpenes [10].

More info on this topic.

Facultative Seral Species

Monterey pine normally invades dry sites with poor, shallow soils. It
also invades oldfields after land clearance, grazing, fire, or logging
[48]. Trees establish in even-aged stands [52].

Monterey pine has intermediate shade tolerance [6,35]. As it matures it
becomes even less tolerant of shade, and shows optimal growth in full
sunlight [5].

The minimum seed-bearing age for Monterey pine is between 5 and 10
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 [25].
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 [52]. The cones of native populations open
infrequently because their habitat is typically cool and moist.
Seedfall is heaviest in warm, dry years [35]. 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 [52]. Seeds can be exposed to a temperature of 203
degrees Fahrenheit (95 deg C) before germination is significantly
reduced [29]. Seedling recruitment is best on mineral soil [52].
Details of growth are discussed in the literature [11].

Monterey pine does not reproduce by sprouting [14,35].

More info on this topic.

More info for the term: phanerophyte

Phanerophyte

More info for the term: tree

Tree

Because Monterey pine exists both  as an overstory and an understory tree, it is classed as  intermediate in tolerance to shade (4)- that is, at least as  tolerant as any other pine in western North America. Age and site  quality, however, affect this assessment. As a sapling or  seedling, the species tolerates shade but becomes less tolerant  in the pole stage and is intolerant when mature (19). When  overtopped, young pines can withstand a considerable amount of  suppression, struggling along for 30 years or more before they  die.

After age 5, the roots of pine seedlings  grow downward as far as soil depth or the clay layer permit. Main  support roots, however, develop in the top 61 cm (24 in), even in  deeper soils (23). Studies at Monterey and Cambria showed at  least a few pine roots penetrated to 1.7 m (5.5 ft) in deeper  soils (8,10). The root system becomes extensive laterally and  roots of mature pines extend from 9 to 12 m (30 to 39 ft) from  the tree (19). Where a layer of organic matter covers the soil,  large numbers of small pine roots exploit the layer for moisture  and nutrients.

    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).

More info on this topic.

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
[35].

Monterey pine does not reproduce  naturally from sprouts, and no record of sprouting in natural  stands is known.

    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.

Although the seeds of Monterey pine  do not require stratification for good performance, germination  is enhanced by it. Cold-moist stratification of 0 to 7 days is  recommended for fresh seed and 7 to 20 days for stored seed. In  one test with no pretreatment of seed, germinative energy was 16  percent in 7 days and germinative capacity 81 percent after 25  days at a controlled temperature of 20° C (68° F). In  another test, again with no pretreatment, but where the day  temperature was held at 30° C (86° F) and the night  temperature at 20° C (68° F), germinative capacity was  67 percent after 28 days (18).

    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).

Fertile cones are  produced as early as 5 to 10 years, but substantial crops are not  yielded until age 15 or 20 if the trees are open-grown, and  considerably later if the stands are dense. Cones mature in the  autumn of the second season and most open during the first warm  days of late winter and early spring. They range in color from  lustrous nut brown to light brown when ripe, and in length from 8  to 18 cm (3 to 7 in). The ellipsoid seeds, jet black and pimpled,  average about 2 cm (0.8 in) long. Monterey pines at Cambria have  the largest cones and seeds; those at Monterey the smallest (11).  Each cone contains from 120 to 200 seeds.

    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.

In its native habitat, Monterey  pine "flowers" in late winter and early spring. The  species is monoecious; the numerous yellow male strobili are  produced on side branches, and female flowers are produced in all  parts of the crown. Monterey pine is multi-nodal and female  strobili occasionally are found at a secondary whorl position  (18).

On good sites, pine saplings that are  free to grow and have at least moderate spacing enlarge rapidly:  an increase in height of 1.2 to 2.4 m (4 to 8 ft) per year has  been observed (23). By age 15, trees are 24 cm (9.4 in) in d.b.h.  and 16 m (53 ft) tall (19). These values indicate a growth rate  for the first 15 years that places Monterey pine among the most  rapidly growing of American conifers. Although reproduction can  be very dense, stands seldom, if ever, stagnate. A few saplings  grow faster than their counterparts, quickly establish dominance,  and eventually form the well-spaced, relatively open stands  typical of older Monterey pine forests.

    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).

Population Differences    The three mainland populations of Monterey pine, although  disjunct, grow where climate and soil are similar. A large  proportion of the total phenotypic variation in several branch,  needle, and cone characteristics, however, is observed between  individual trees at each location. The Cambria population,  although less variable than the other two, differs from them in  several cone, branch, and needle characteristics. In Australia  these differences, plus a slower growth rate and a different  pattern of seasonal growth, suggest that the Cambria population  differs genetically from the northern populations (11). A recent  study, however, indicates little genetic differentiation among  the native populations. Most of the genetic variation is located  within each stand (26).

    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.

The following is a representative barcode sequence, the centroid of all available sequences for this species.


No available public DNA sequences.

Download FASTA File

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 7
Specimens with Barcodes: 24
Species With Barcodes: 1

Information on state- and province-level protection status of plants in the
United States and Canada is available at NatureServe.

Mexico

Rounded National Status Rank: N1 - Critically Imperiled

United States

Rounded National Status Rank: N1 - Critically Imperiled

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).

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).

Major Threats

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.

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.

More info for the term: natural

Cone processing and nursery practices are discussed in the literature
[11,25].

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 [35].

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 [39]. Monterey
pine is the subject of a genetic conservation program [27].

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.

Monterey pine is valued for shade and as an ornamental [33,35]. It
provides a barrier to wind and noise [35,53]. It is also used for
Christmas trees [35].

Monterey pine wood is light, soft, and coarse grained [35,43]. It is of
little commercial value in the United States except as fuelwood [35].
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 [4].

Monterey pine is planted for erosion control [35]. Ease of
establishment and a widespreading root system make it a good species for
stabilizing soils on steep slopes [28].

Goats, black-tailed deer, and porcupine browse Monterey pine. Porcupine
also eat the bark [27,30,35]. Birds and small mammals consume the seeds
[35].

The wood of Monterey pine is light, soft, brittle, and  coarse-grained. The trunk is characterized by a large amount of  crook and other irregularities, a small percentage of clear bole,  and frequent presence of disease. These characteristics cause the  species to be of little commercial value for lumber and wood  products in the United States. Past commodity use has been for  coarse lumber in a localized market and for fuelwood. In marked  contrast, the species is valued for wood products in many other  countries.

    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.

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).

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 has an extremely narrow natural range: three coastal areas in California (one in San Mateo and Santa Cruz counties, one in Monterey County, and one in San Luis Obispo County) and off the coast of Baja California, Mexico (Guadalupe Island and debatably also on Cedros Island). Some natural populations of the species are under protection. Along the California coast it has escaped from cultivation, and from there into southern coastal Oregon it shows signs of naturalizing. 

 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).

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.