Index of Species Information

SPECIES:  Pinus washoensis


SPECIES: Pinus washoensis
AUTHORSHIP AND CITATION : Esser, Lora L. 1993. Pinus washoensis. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: [].

ABBREVIATION : PINWAS SYNONYMS : NO-ENTRY SCS PLANT CODE : PIWA COMMON NAMES : Washoe pine yellow pine TAXONOMY : The currently accepted scientific name of Washoe pine is Pinus washoensis Mason and Stockw. [3,8,9]. There are no recognized subspecies, varieties, or forms. Washoe pine origins are uncertain. Haller [29] proposed that Washoe pine resulted from hybridization between either Pacific ponderosa pine (P. ponderosa var. ponderosa) and Jeffrey pine (P. jeffreyi) or Pacific ponderosa pine and Rocky Mountain ponderosa pine (P. ponderosa var. scopulorum). Mirov [30] dismissed Jeffrey pine as a possible ancestor on chemical and morphological grounds, suggesting that Washoe pine is a variety or mutant of ponderosa pine. Critchfield [4] stated that Washoe pine is a Pleistocene derivative of Rocky Mountain ponderosa pine. Washoe pine sets more sound seed per cone in artificial crosses with Rocky Mountain ponderosa pine than in natural intraspecific crosses. This rare instance of heterosis for seed set in interspecific conifer hybrids establishes a strong and direct evolutionary relationship between Washoe pine and the Rocky Mountain ponderosa pine [17]. Washoe pine hybridizes with Pacific ponderosa pine [17,26] and rarely with Jeffrey pine [4]. LIFE FORM : Tree FEDERAL LEGAL STATUS : No special status OTHER STATUS : NO-ENTRY


SPECIES: Pinus washoensis
GENERAL DISTRIBUTION : Washoe pine occurs in three mountain ranges on the western rim of the Great Basin in northeastern California and northwestern Nevada [3,4,17]. It occupies a few square miles on the east slopes of Mount Rose, Nevada, and can be found in small stands in the southern Warner Mountains and in the Bald Mountain range of northeastern California [3,4]. Isolated stands have been reported in Oregon and British Columbia [4,16]. ECOSYSTEMS : FRES21 Ponderosa pine FRES23 Fir - spruce FRES26 Lodgepole pine STATES : CA NV OR BC BLM PHYSIOGRAPHIC REGIONS : 4 Sierra Mountains 5 Columbia Plateau KUCHLER PLANT ASSOCIATIONS : K005 Mixed conifer forest K007 Red fir forest K008 Lodgepole pine - subalpine forest SAF COVER TYPES : 207 Red fir 208 Whitebark pine 211 White fir 218 Lodgepole pine 237 Interior ponderosa pine 238 Western juniper 243 Sierra Nevada mixed conifer 247 Jeffrey pine SRM (RANGELAND) COVER TYPES : NO-ENTRY HABITAT TYPES AND PLANT COMMUNITIES : Washoe pine typically occurs in pure stands at higher elevations along the eastern slope of the Sierra Nevada. In the northern Sierra Nevada and into the southern Cascade Range, it forms mixed stands with Jeffrey pine, Pacific ponderosa pine, incense cedar (Libocedrus decurrens), white fir (Abies concolor), California red fir (A. magnifica), and western juniper (Juniperus occidentalis) [4,10,14,16,21]. Other common tree associates include sugar pine (Pinus lambertiana) and quaking aspen (Populus tremuloides var. aurea). Other associates include mountain sweetroot (Osmorhiza chilensis), white hawkweed (Hieracium albiflorum), greenleaf manzanita (Arctostaphylos patula), mountain big sagebrush (Artemesia tridentata ssp. vaseyana), antelope bitterbrush (Purshia tridentata), snowbrush ceanothus (Ceanothus velutinus), wooly wyethia (Wyethia mollis), snowberry (Symphoricarpos vaccinioides), Idaho fescue (Festuca idahoensis), Wheeler bluegrass (Poa nervosa), and Orcutt brome (Bromus orcuttianus) [1,10,14,18,20,21]. Publications listing Washoe pine as a dominant species are: Preliminary descriptions of the terrestrial natural communities of California [10] Symposium Proceedings--plant communities of southern California [13] Forest habitat types of the South Warner Mountains, Modoc County, California [20] Montane and subalpine vegetation of the Sierra Nevada and Cascade Ranges [21].


SPECIES: Pinus washoensis
IMPORTANCE TO LIVESTOCK AND WILDLIFE : The avian species composition of stands containing Washoe pine depends on the stage of succession. A fire burned 450,000 acres (18,000 ha) of a yellow pine (Washoe, Jeffrey, and ponderosa pines)-fir forest near Truckee, California, in 1960. At postfire years 6 to 8, nine species of birds were unique to the burned areas, six to the unburned area, and 17 were found on both sites. Shrub cover on the burned plot increased from about 20 percent to over 43 percent from postfire year 6 to 25, and birds that nest and feed in shrubs increased by over 500 percent. Throughout the study, bird numbers remained relatively stable in the unburned forest. On the burned plot, however, primary-cavity nesting birds declined over time. The decline probably resulted from a decrease in standing dead trees. Snag density declined from about 65 per acre (26/ha) in 1966 to less than 12.5 per acre (<5/ha) in 1985 [18]. PALATABILITY : NO-ENTRY NUTRITIONAL VALUE : NO-ENTRY COVER VALUE : NO-ENTRY VALUE FOR REHABILITATION OF DISTURBED SITES : NO-ENTRY OTHER USES AND VALUES : NO-ENTRY OTHER MANAGEMENT CONSIDERATIONS : On eastern-slope yellow pine forests of northeastern California, logging has decreased pines (ponderosa, Jeffrey, and Washoe pines) relative to white fir and western juniper [14].


SPECIES: Pinus washoensis
GENERAL BOTANICAL CHARACTERISTICS : Washoe pine is a native conifer which grows up to 115 feet (35 m) tall and 5 feet (1.5 m) in diameter. It has a conic or flat-topped crown [9]. The short, stout needles occur in bundles of three and are 4 to 6 inches (10-15 cm) long [4]. The seed cones are 2 to 3.2 inches (5-8 cm) long and have short-winged seeds [4]. The bark is shallowly furrowed [9]. The oldest Washoe pine is on Mount Rose, Nevada. Its estimated age in 1962 exceeded 300 years. Several other trees in the area have estimated ages of 100 to 250 years [4]. RAUNKIAER LIFE FORM : Phanerophyte REGENERATION PROCESSES : Literature specific to Washoe pine regeneration is sparse. In the Mount Rose population, Washoe pine exhibits low seed production and has low reproductive capacity [4,17]. SITE CHARACTERISTICS : Washoe pine is common on broad ridgetops and north-facing slopes [18,20]. It may occur on other aspects; on volcanic ridges south of the Warner Wilderness area, it comprises 50 to 75 percent of total stocking on gentle west- and southwest-facing slopes [21]. Best growth occurs on well-drained soils [9]. Washoe pine occurs from 5,500 to 8,500 feet (1,650-2,550 m) elevation [4,9,10]. An isolated population in British Columbia, Canada, occurs at 4,818 feet elevation (1,460 m) [4]. SUCCESSIONAL STATUS : Facultative Seral Species Washoe pine is a long-lived seral species in white fir communities [20]. It is plentiful in the community, with cover often equaling or exceeding white fir. Fir reproduction usually exceeds that of Washoe pine, however, unless fires are fairly frequent [20]. Washoe pine is dominant at higher elevations [14,20]. SEASONAL DEVELOPMENT : Washoe pine pollen is shed from June 24 to July 4 on Mount Rose [4]. Cones mature in August and September and open in September throughout its range [27]. Natural seedling dormancy begins when soil temperature is below 50 degrees Fahrenheit (10 deg C) [11]. In the nursery, Washoe pine seedlings cease visible top growth by mid-October and visible root growth by late November. In January top growth is evident. The first traces of renewed root growth appear in late February and bud swell begins in late March [11].


SPECIES: Pinus washoensis
FIRE ECOLOGY OR ADAPTATIONS : Before settlement, eastern-slope yellow pine communities of northeastern California generally consisted of either monotypic stands or mixtures of Washoe, ponderosa, and Jeffrey pines. Structurally, eastside pine forests usually consisted of widely scattered, large trees. Low-severity fires were frequent, but forests may have had occasional stand-replacing fires [14,28]. Canopy closures probably ranged from about 30 percent on dry sites to 80 percent in the most productive areas. A 1917 report stated that yellow pines of the area were often only four-log trees (a standard log was 16 feet long), suggesting that mature trees were shorter than 100 feet (30 m) [14]. Susceptibility to fire in mid-elevation Washoe pine stands has increased since 1850 because of fuel buildups and increased stocking of white fir. Juniper and shrub cover have replaced the typical shrub/grass understory at low elevations as a result of livestock grazing and fire suppression [14]. POSTFIRE REGENERATION STRATEGY : Tree without adventitious-bud root crown


SPECIES: Pinus washoensis
IMMEDIATE FIRE EFFECT ON PLANT : Literature concerning fire effects specific to Washoe pine is lacking. However, many of the yellow pines harvested in northeastern California during the early 1900's survived earlier fires. Stumps 16 to 36 inches (40.6-81.4 m) tall usually remained after harvest. The lowest portions of the trees were left because they were defective from fire scarring or accumulation of pitch from low-intensity fires [14]. DISCUSSION AND QUALIFICATION OF FIRE EFFECT : NO-ENTRY PLANT RESPONSE TO FIRE : Literature specific to Washoe pine's response to fire is lacking. DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : NO-ENTRY FIRE MANAGEMENT CONSIDERATIONS : Fire suppression in white fir habitat types in northeastern California leads to an increase in white fir, with a corresponding decrease in pine species (including Washoe pine) reproduction [20]. A yellow pine-fir forest in the eastern Sierra Nevada near Truckee, California, burned in a 1960 wildfire. In 1965, the burned plot had greater cover of shrubs, herbs, and grasses than an adjacent unburned plot. From 1966 to 1985 shrub cover increased while herbaceous cover decreased. In postfire year 15 yellow pines were the dominant trees, although white and California red fir were present. Yellow pines codominated with the firs in nearby unburned stands. Data are shown below [18]: postfire year 15 density/ha basal area (sq.m/ha) burned plot yellow pine complex 97.4 3.1 white and California red fir 4.5 1.7 unburned plot yellow pine complex 335.5 24.2 white and California red fir 448.8 15.1 The responses of small birds to succession after this wildfire demonstrates the potential effectiveness of increasing habitat diversity, spatially and temporally, on breeding bird populations [22]. In the eastside yellow pine forests of northeastern California, fuel loading has increased over time. Early logging operations increased slash and fire hazards. Invasion of eastside pine lands by cheatgrass (Bromus tectorum) and increases of woody shrubs, dense thickets of young trees, and accretion of woody debris have increased the probability of stand-replacing fires [14].


SPECIES: Pinus washoensis
REFERENCES : 1. Allen-Diaz, Barbara H. 1991. Water table and plant species relationships in Sierra Nevada meadows. American Midland Naturalist. 126: 30-43. [16149] 2. 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] 3. 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] 4. Critchfield, William B. 1984. Crossability and relationships of Washoe pine. Madrono. 31(3): 144-170. [21749] 5. Duffield, J. W. 1953. Pine pollen collection dates--annual and geographic variation. For. Res. Notes No. 85. Berkeley, CA: U.S. Department of Agriculture, Forest Service, California Forest and Range Experiment Station. 9 p. [17970] 6. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. [905] 7. 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] 8. 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] 9. Hickman, James C., ed. 1993. The Jepson manual: Higher plants of California. Berkeley, CA: University of California Press. 1400 p. [21992] 10. Holland, Robert F. 1986. Preliminary descriptions of the terrestrial natural communities of California. Sacramento, CA: California Department of Fish and Game. 156 p. [12756] 11. Jenkinson, James L. 1980. Improving plantation establishment by optimizing growth capacity and planting time of western yellow pine. Res. Pap. PSW-154. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 22 p. [17966] 12. 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] 13. Latting, June, ed. 1976. Symposium proceedings--plant communities of southern California. Special Publication No. 2. Berkeley, CA: California Native Plant Society. 164 p. [1414] 14. Laudenslayer, William F., Jr.; Darr, Herman H.; Smith, Sydney. 1989. Historical effects of forest management practices on eastside pine communities in northeastern California. In: Tecle, Aregai; Covington, W. Wallace; Hamre, R. H., technical coordinators. Multiresource management of ponderosa pine forests: Proceedings of the symposium; 1989 November 14-16; Flagstaff, AZ. Gen. Tech. Rep. RM-185. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station: 26-34. [11305] 15. 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] 16. Munz, Philip A. 1973. A California flora and supplement. Berkeley, CA: University of California Press. 1905 p. [6155] 17. Niebling, Charles R.; Conkle, M. Thompson. 1990. Diversity of Washoe pine and comparisons with allozymes of ponderosa pine races. Canadian Journal of Forest Research. 20(3): 298-308. [15841] 18. Raphael, Martin G.; Morrison, Michael L.; Yoder-Williams, Michael P. 1987. Breeding bird populations during twenty-five years of postfire succession in the Sierra Nevada. Condor. 89: 614-626. [6873] 19. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. [2843] 20. Riegel, Gregg M.; Thornburgh, Dale A.; Sawyer, John O. 1990. Forest habitat types of the South Warner Mountains, Modoc County, California. Madrono. 37(2): 88-112. [11466] 21. Rundel, Philip W.; Parsons, David J.; Gordon, Donald T. 1977. Montane and subalpine vegetation of the Sierra Nevada and Cascade Ranges. In: Barbour, Michael G.; Major, Jack, eds. Terrestrial vegetation of California. New York: John Wiley & Sons: 559-599. [4235] 22. Severson, Kieth E.; Rinne, John N. 1990. Increasing habitat diversity in Southwestern forests and woodlands via prescribed fire. In: Krammes, J. S., technical coordinator. Effects of fire management of Southwestern natural resources: Proceedings of the symposium; 1988 November 15-17; Tucson, AZ. Gen. Tech. Rep. RM-191. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station: 94-104. [11277] 23. 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. 7 p. [20090] 24. 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] 25. Vasek, Frank C.; Thorne, Robert F. 1977. Transmontane coniferous vegetation. In: Barbour, Michael G.; Major, Jack, eds. Terrestrial vegetation of California. New York: John Wiley & Sons: 797-832. [4265] 26. Wells, Osborn O. 1964. Geographic variation in ponderosa pine. I. The ecotypes and their distribution. Silvae Genetica. 13(4): 89-103. [15928] 27. 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] 28. Vale, Thomas R. 1977. Forest changes in the Warner Mountains, California. Annals of the Association of American Geographers. 67(1): 28-45. [20226] 29. Haller, John R. 1962. Variation and hybridization in ponderosa and jeffrey pines. University of California Publications in Botany. Berkeley, CA: University of California Press; 34(2): 129-166. [1064] 30. Mirov, N. T. 1961. Composition of gum turpentines of pines. Tech. Bull. No. 1239. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 158 p. [22164]

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