Index of Species Information
SPECIES: Pinus torreyana
Introductory
SPECIES: Pinus torreyana
AUTHORSHIP AND CITATION :
Esser, Lora L. 1993. Pinus torreyana. In: Fire Effects Information
System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain
Research Station, Fire Sciences Laboratory (Producer). Available:
https://www.fs.usda.gov/database/feis/plants/tree/pintor/all.html [].
ABBREVIATION :
PINTOR
SYNONYMS :
NO-ENTRY
SCS PLANT CODE :
PITO
COMMON NAMES :
Torrey pine
Santa Rosa Island Torrey pine
Del Mar pine
Soledad pine
TAXONOMY :
The currently accepted scientific name of Torrey pine is Pinus torreyana
Parry. There are no recognized varieties or forms. There are two
recognized subspecies [14,34]:
Pinus torreyana ssp. insularis Haller
Pinus torreyana ssp. torreyana.
LIFE FORM :
Tree
FEDERAL LEGAL STATUS :
No special status
OTHER STATUS :
Both subspecies of Torrey pine are listed in Category 1B by the
California Native Plant Society: rare or endangered in California [41].
DISTRIBUTION AND OCCURRENCE
SPECIES: Pinus torreyana
GENERAL DISTRIBUTION :
Torrey pine is the rarest pine in North America [9]. The natural
distribution of Torrey pine consists of two disjunct populations. The
mainland population, in and near the Torrey Pines State Reserve (TPSR),
is confined to the low coastal bluffs flanking the Soledad Valley in San
Diego County, California. It consists of approximately 7,000 trees
[7,22]. The other population occurs on Santa Rosa Island off the coast
of southern California, 175 miles (280 km) northwest of the mainland
population [7,13,22]. This population consists of approximately 2,000
trees [20].
ECOSYSTEMS :
FRES34 Chaparral - mountain shrub
STATES :
CA
BLM PHYSIOGRAPHIC REGIONS :
3 Southern Pacific Border
KUCHLER PLANT ASSOCIATIONS :
K033 Chaparral
K035 Coastal sagebrush
SAF COVER TYPES :
NO-ENTRY
SRM (RANGELAND) COVER TYPES :
NO-ENTRY
HABITAT TYPES AND PLANT COMMUNITIES :
The Torrey pine forest is the only southern California coastal pine
forest [26,33]. Torrey pine part of the California closed-cone pine
forests [37,41]. These forests merge with coastal sage scrub,
chaparral, dune scrub, and coastal salt marsh [37]. On Santa Rosa
Island, Torrey pine is a member of the Torrey pine woodland. This
community ranges from a monotypic assemblage of Torrey pine with a
litter understory to more open stands that resemble woodlands mixed with
California scrub oak (Quercus dumosa) and shrubs [5].
Torrey pine is listed as a codominant or dominant species in the
following publications:
Plant communities of Santa Rosa Island, Channel Islands National Park [5]
The closed-cone pines and cypress [37]
Preliminary descriptions of the terrestrial natural communities of
California [41]
Plant communities of southern California [42].
Some species commonly associated with Torrey pine include chamise
(Adenostoma fasciculatum), California sagebrush (Artemesia californica),
toyon (Heteromeles arbutifolia), lemonadeberry (Rhus integrifolia),
California scrub oak, mule fat (Baccharis viminea), bush poppy
(Dendromecon rigida), California encelia (Encelia californica), white
sage (Salvia apiana), black sage (S. mellifera), saw-toothed goldenbush
(Haplopappus squarrosus), Costa Baja manzanita (Arctostaphylos
glandulosa ssp. crassifolia), Santa Rosa Island manzanita (A.
confertiflora), California buckwheat (Eriogonum fasciculatum),
warty-stem ceanothus (Ceanothus verrucosus), feltleaf ceanothus (C.
arboreus), western yarrow (Achillea millefolium), sea fig (Carpobrotus
chilensis), iceplant (Mesembryanthemum spp.), Indian paintbrush
(Castilleja spp.), monkeyflower (Mimulus spp.), California poppy
(Eschscholzia californica), sedge (Carex globosa), oniongrass (Melica
imperfecta), bent grass (Agrostis spp.), slender wild oat (Avena
barbata), and purple cudweed (Gnaphalium purpureum).
MANAGEMENT CONSIDERATIONS
SPECIES: Pinus torreyana
IMPORTANCE TO LIVESTOCK AND WILDLIFE :
Seeds of Torrey pine are eaten by birds, rodents, and other mammals.
The dusky-footed and desert woodrats consume large quantities of Torrey
pine seeds and may greatly reduce their numbers in the seedbank [26].
PALATABILITY :
NO-ENTRY
NUTRITIONAL VALUE :
NO-ENTRY
COVER VALUE :
NO-ENTRY
VALUE FOR REHABILITATION OF DISTURBED SITES :
Torrey pines are planted on wildlands and disturbed sites in San Diego,
California. Near Point Loma, San Diego, they provide wildlife habitat
and protect existing coastal sage scrub shrubs [19].
OTHER USES AND VALUES :
Torrey pine is widely planted as an ornamental and has been evaluated as
a commercial species in Kenya, Australia, and New Zealand [26].
OTHER MANAGEMENT CONSIDERATIONS :
The Torrey pine population in TPSR consists of large, mature
individuals; seedlings and saplings are infrequent [40]. Given the low
rate of seedling establishment and survival in the recent past, stand
age of Torrey pine will continue to increase within the TPSR [26].
Cattle grazing has significantly reduced the amount of native shrub
cover within Torrey pine stands on Santa Rosa Island. The average
amount of open ground on four transects on Santa Rosa Island is about 78
percent compared to 30 percent on the mainland. Seedling establishment
is higher on Santa Rosa Island than on the mainland [26].
Because of low genetic variability, Torrey pine has little capacity to
respond to change through natural selection. Native populations should
be managed to maintain the maximum number of trees possible to minimize
the chance of catastrophic loss [21].
Both the island and mainland populations of Torrey pine are threatened
by air pollution. The mainland population is adjacent to densely
populated areas that generate extreme amounts of air pollution. The
island population is threatened by seasonal easterly Santa Ana winds
carrying air with high concentrations of ozone and other pollutants from
the Los Angeles Basin [8,22].
In 1988, a bark beetle (Ips paraconfusus) infestation occurred at TPSR.
By 1990, 12 percent of the adult trees had been killed. In 1991, the
U.S. Forest Service utilized synthetic pheromones to lure ips beetles
into traps placed on trees. Nine weeks after placement of the traps
130,000 beetles were captured [2]. Only one additional tree was
attacked after the trapping began. The number of trapped beetles
eventually fell to about 100 per week [2].
BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Pinus torreyana
GENERAL BOTANICAL CHARACTERISTICS :
Torrey pine is a native, slow-growing tree endemic to California
[25,30]. It grows from 25 to 60 feet (7.5-18 m) tall, but is usually
around 40 feet (12 m) in height [17,33]. The mature crown is open and
rounded with many large branches [14]. The needles are in fascicles of
5 and are 8 to 12 inches (20-30 cm) long [16]. The bark is rough and
flaky [16]. Cones are large, 4 to 6 inches (10.2-15.2 cm) wide, and
long. They are harder and heavier than most other pine cones [33].
Torrey pine taproots may reach 25 feet (7.5 m) into sandstone, and
lateral roots can extend up to 225 feet (67.5 m) from the trunk [9].
The oldest Torrey pines are about 150 years old [21].
RAUNKIAER LIFE FORM :
Phanerophyte
REGENERATION PROCESSES :
Torrey pine regenerates sexually. It does not reproduce naturally by
vegetative methods.
Seed production and dissemination: Torrey pines begin to produce seed
when they are 12 to 18 years old. Torrey pine exhibits delayed seed
dispersal, a pattern of seed release intermediate between open- and
closed-cone species. In the TPSR, Torrey pine cones begin to open when
seeds are mature, but seed fall continues for up to 13 years after cone
maturity. Over 76 percent of available seeds were in cones 1 or more
years after seed maturity [27]. Seed release accelerates through the
fourth year when cones retain 22 percent of seeds, and then levels off
or slowly declines [27]. Over 15 percent of the original seed is
retained 11 years following cone maturity [26]. At age 14, cones are
mostly open but still retain about 10 percent of seed [14]. Torrey
pines on Santa Rosa Island may release seed more rapidly than those in
the TPSR [26].
Seed viability decreases with cone age, but seeds at least partially
exposed for 10 years remain viable [27]. Predispersal loss of seed is
high in Torrey pine. Before dispersal, 6.8 percent of seed is lost to
arthropod seed predators within the cone and 4.6 percent of seed has
already germinated. Germination of seed in the cone is unique to Torrey
pine in the genus Pinus [26,27]. The seed of Torrey pine is nearly
wingless; wind dispersal is negligible. Birds such as scrub jays aid in
seed dissemination [9,20].
Seedling development: Cold stratification periods of 30 to 90 days at
33 to 41 degrees Fahrenheit (.56-5 deg C) are recommended for rapid and
complete germination [17]. Seedling mortality is largely a function of
water stress and is highest in July and August. Seedling establishment
increases with disturbance such as fire. Very few seedlings are
currently survive to reproductive age [26].
SITE CHARACTERISTICS :
Torrey pine has adapted to a harsh environment of poor soils and little
moisture [33]. The climate is maritime with low winter rainfall and
frequent fog [40]. The species occurs in scattered groves or is widely
dispersed on ridgetops, slopes, and gullies. It is also found in
coastal highlands, canyons, and mesas [4,16]. It grows in open,
shallow, humus-poor, sandy soils [33,40]. Torrey pine is found at
elevations of 200 to 500 feet (60-150 m) [13].
SUCCESSIONAL STATUS :
Facultative Seral Species
Torrey pine is shade tolerant. Approximately 90 percent of Torrey pine
seedlings are found under adult trees [26].
SEASONAL DEVELOPMENT :
Torrey pine is monoecious. Cones are pollinated from January to March
and reach maturity in the summer two and a half years later [26]. Cone
opening initiates when seeds are mature [14]. Seed dispersal begins in
September after cone-ripening [16,17].
FIRE ECOLOGY
SPECIES: Pinus torreyana
FIRE ECOLOGY OR ADAPTATIONS :
Torrey pine exhibits delayed seed dispersal which is beneficial in the
event of fire [11,28]. Some seeds are released immediately after fire
and exploit postfire conditions such as sterilized soil, reduced
competition from other species, and the absence of seed-eating rodents
[11]. Other seeds are released gradually and increase Torrey pine
stocking. Cones can be retained on trees and release viable seed for up
to 15 years [28].
McMasters [27] stated that delayed seed dispersal of Torrey pine and
reduced serotiny of other coastal and insular conifers may arise form
the same cause: a fire pattern in which large scale, intense crown
fires have alternated with long intervals in which ther were no fires at
all or in which there were only low-severity surface fires.
FIRE REGIMES :
Find fire regime information for the plant communities in which this
species may occur by entering the species name in the FEIS home page under
"Find Fire Regimes".
POSTFIRE REGENERATION STRATEGY :
Tree without adventitious-bud root crown
Crown residual colonizer (on-site, initial community)
Secondary colonizer - off-site seed
FIRE EFFECTS
SPECIES: Pinus torreyana
IMMEDIATE FIRE EFFECT ON PLANT :
Torrey pine is fire-intolerant [40]. Low-severity fires will kill trees
up to 21 inches (52 cm) dbh even if no crown damage is sustained [40].
Severe fires kills trees of all sizes [26].
DISCUSSION AND QUALIFICATION OF FIRE EFFECT :
NO-ENTRY
PLANT RESPONSE TO FIRE :
Seed drop is substantial after crown fires [26,40]. Establishment of
seedlings from stored seeds released by fire-killed trees has been
confirmed after both wildfires and prescribed fires [39].
An arson fire in TPSR occurred on July 12, 1972. Ninety-three mature
trees were killed on 11.3 acres (4.8 ha). Seedling establishment
occurred in postfire year 1 [27]. In May of 1979, 220 saplings and
seedlings were found in the burned area. Juvenile tree density was two
and a half times greater than the prefire mature tree density [26,27].
On November 6 and 7, 1978, 31,204 square feet (2,900 sq m) were burned
in the TPSR under controlled conditions. Results on Torrey pine
regeneration were inconclusive. However, prescribed fires in the spring
of 1984 and winter of 1985, which killed 19 trees and 17 saplings, did
promote seedling establishment. In January 1986, a total of 201
seedlings were found in the burned area [40].
DISCUSSION AND QUALIFICATION OF PLANT RESPONSE :
NO-ENTRY
FIRE MANAGEMENT CONSIDERATIONS :
Torrey pine may be declining in the TPSR because past fire-exclusion
policies have created an unnatural setting. Infrequent, severe fires
are best for Torrey pine seedling establishment, although disturbance is
not essential to seedling establishment [26]. According to Zedler and
others [40], maintaining a natural system in the TPSR may require that
it be allowed to burn to the ground every century [40]. If fires occur
in a Torrey pine population at intervals shorter than 12 to 18 years,
(when saplings begin to produce cones), they could seriously impair the
ability of the population to survive [26].
References for species: Pinus torreyana
1. Bernard, Stephen R.; Brown, Kenneth F. 1977. Distribution of mammals, reptiles, and amphibians by BLM physiographic regions and A.W. Kuchler's associations for the eleven western states. Tech. Note 301. Denver, CO: U.S. Department of the Interior, Bureau of Land Management. 169 p. [434]
2. Berson, David Ross. 1992. Pheromones help save Torrey pines. Forestry Research West. Fort Collins, CO: U.S. Department of Agriculture, Forest Service; September: 17-20. [20647]
3. Borchert, Mark. 1985. Serotiny and cone-habit variation in populations of Pinus coulteri (Pinaceae) in the southern Coast Ranges of California. Madrono. 32(1): 29-48. [5997]
4. Brown, David E. 1982. Relict conifer forests and woodlands. In: Brown, David E., ed. Biotic communities of the American Southwest--United States and Mexico. Desert Plants. 4(1-4): 70-71. [8888]
5. Clark, Ronilee A.; Halvorson, William L.; Sawdo, Andell A.; Danielsen, Karen C. 1990. Plant communities of Santa Rosa Island, Channel Islands National Park. Tech. Rep. No. 42. Davis, CA: University of California at Davis, Institute of Ecology, Cooperative National Park Resources Studies Unit. 93 p. [18245]
6. Clements, Frederic E. 1934. The relict method in dynamic ecology. Journal of Ecology. 22: 39-68. [11632]
7. Critchfield, William B.; Little, Elbert L., Jr. 1966. Geographic distribution of the pines of the world. Misc. Publ. 991. Washington, DC: U.S. Department of Agriculture, Forest Service. 97 p. [20314]
8. Davis, Gary E. 1989. Design of a long-term ecological monitoring program for Channel Islands National Park, California. Natural Areas Journal. 9(2): 80-89. [9743]
9. Dusek, Karen H. 1985. Update on our rarest pine. American Forests. 91: 26-29, 61, 63. [21996]
10. El-Kassaby, Y. A. 1992. Domestication and genetic diversity--should we be concerned? Forestry Chronicle. 68(6): 687-700. [20683]
11. Evarts, Bill. 1986. Torrey pines: resurrection or remission. Environment Southwest. 514: 3-8. [5602]
12. Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; [and others]. 1977. Vegetation and environmental features of forest and range ecosystems. Agric. Handb. 475. Washington, DC: U.S. Department of Agriculture, Forest Service. 68 p. [998]
13. Griffin, James R.; Critchfield, William B. 1972. The distribution of forest trees in California. Res. Pap. PSW-82. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 118 p. [1041]
14. Hickman, James C., ed. 1993. The Jepson manual: Higher plants of California. Berkeley, CA: University of California Press. 1400 p. [21992]
15. Keeley, Jon E.; Keeley, Sterling C. 1988. Chaparral. In: Barbour, Michael G.; Billings, William Dwight, eds. North American terrestrial vegetation. Cambridge; New York: Cambridge University Press: 165-207. [19545]
16. Krochmal, Arnold; Krochmal, Connie. 1982. Uncultivated nuts of the United States. Agriculture Information Bulletin 450. Washington, DC: U.S. Department of Agriculture, Forest Service. 89 p. [1377]
17. Krugman, Stanley L.; Jenkinson, James L. 1974. Pinaceae--pine family. In: Schopmeyer, C. S., technical coordinator. Seeds of woody plants in the United States. Agric. Handb. 450. Washington, DC: U.S. Department of Agriculture, Forest Service: 598-637. [1380]
18. Kuchler, A. W. 1964. Manual to accompany the map of potential vegetation of the conterminous United States. Special Publication No. 36. New York: American Geographical Society. 77 p. [1384]
19. La Rosa, Ronald. 1982. Coastal sage environmental conservation--the Navy's experience at Point Loma. In: Conrad, C. Eugene; Oechel, Walter C., technical coordinators. Proceedings of the symposium on dynamics and management of Mediterranean-type ecosystems; 1981 June 22-26; San Diego, CA. Gen. Tech. Rep. PSW-58. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station: 614. [6086]
20. Ledig, F. Thomas; Conkle, M. Thompson. 1983. Gene diversity and genetic structure in a narrow endemic, Torrey pine (Pinus torreyana Parry ex Carr.). Evolution. 37(1): 79-85. [21754]
21. Ledig, F. Thomas. 1984. Gene conservation, endemics, and California's Torrey pine. Fremontia. 12(3): 9-13. [21828]
22. Little, Elbert L., Jr. 1975. Rare and local conifers in the United States. Conservation Research Rep. No. 19. Washington, DC: U.S. Department of Agriculture, Forest Service. 25 p. [15691]
23. Little, Elbert L., Jr. 1979. Checklist of United States trees (native and naturalized). Agric. Handb. 541. Washington, DC: U.S. Department of Agriculture, Forest Service. 375 p. [2952]
24. Mason, Herbert L. 1927. Fossil records of some West American conifers. Publications of the Carnegie Institute. 346: 139-159. [10707]
25. McCune, Bruce. 1988. Ecological diversity in North American pines. American Journal of Botany. 75(3): 353-368. [5651]
26. McMaster, Gregory Scott. 1980. Patterns of reproduction in Torrey pine (Pinus torreyana). San Diego, CA: San Diego State University. 112 p. Thesis. [21982]
27. McMaster, Gregory S.; Zedler, Paul H. 1981. Delayed seed dispersal in Pinus torreyana (Torrey pine). Oecologia. 51: 62-66. [21615]
28. McMaster, Gregory S. 1982. Fire in the ecology and management of Torrey pine (Pinus torreyana) populations. In: Conrad, C. Eugene; Oechel, Walter C., technical coordinators. Proceedings of the symposium on dynamics and management of Mediterranean-type ecosystems; 1981 June 22-26; San Diego, CA. Gen. Tech. Rep. PSW-58. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station: 618. [6089]
29. Millar, Constance I.; Marshall, Kimberly A. 1991. Allozyme variation of Port-Orford cedar (Chamaecyparis lawsoniana): implications for genetic conservation. Forest Science. 37(4): 1060-1077. [18336]
30. Munz, Philip A. 1973. A California flora and supplement. Berkeley, CA: University of California Press. 1905 p. [6155]
31. Owens, John N. 1986. Cone and seed biology. In: Shearer, Raymond C., compiler. Proceedings--conifer tree seed in the Inland Mountain West symposium; 1985 August 5-6; Missoula, MT. Gen. Tech. Rep. INT-203. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 14-31. [12782]
32. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. [2843]
33. Remeika, Paul. 1976. Torrey pines. Environment Southwest. 475: 10-12. [21830]
34. Smith, James Payne, Jr.; Berg, Ken. 1988. Inventory of rare and endangered vascular plants of California. 4th ed. Special Publication No. 1. Sacramento, CA: California Native Plant Society. 168 p. [7494]
35. Stickney, Peter F. 1989. Seral origin of species originating in northern Rocky Mountain forests. Unpublished draft on file at: U.S. Department of Agriculture, Forest Service, Intermountain Research Station, Fire Sciences Laboratory, Missoula, MT; RWU 4403 files. 10 p. [20090]
36. U.S. Department of Agriculture, Soil Conservation Service. 1982. National list of scientific plant names. Vol. 1. List of plant names. SCS-TP-159. Washington, DC. 416 p. [11573]
37. Vogl, Richard J.; Armstrong, Wayne P.; White, Keith L.; Cole, Kenneth L. 1977. The closed-cone pines and cypress. In: Barbour, Michael G.; Major, Jack, eds. Terrestrial vegetation of California. New York: John Wiley and Sons: 295-358. [7219]
38. Waters, Elizabeth R.; Schaal, Barbara A. 1991. No variation is detected in the chloroplast genome of Pinus torreyana. Canadian Journal of Forest Research. 21: 1832-1835. [21745]
39. Zedler, Paul H. 1986. Closed-cone conifers of the chaparral. Fremontia. 14(3): 14-17. [18648]
40. Zedler, Paul H.; Scheid, Gerald; Scheidlinger, Carla. 1987. Fire in the ecology and management of Torrey pine (California). Restoration & Management Notes. 5(2): 88-89. [3844]
41. Holland, Robert F. 1986. Preliminary descriptions of the terrestrial natural communities of California. Sacramento, CA: California Department of Fish and Game. 156 p. [12756]
42. Thorne, Robert F. 1976. The vascular plant communities of California. In: Latting, June, ed. Symposium proceedings: plant communities of southern California; 1974 May 4; Fullerton, CA. Special Publication No. 2. Berkeley, CA: California Native Plant Society: 1-31. [3289]
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