Index of Species Information

SPECIES:  Toxicodendron diversilobum

Introductory

SPECIES: Toxicodendron diversilobum
AUTHORSHIP AND CITATION : Howard, Janet L. 1994. Toxicodendron diversilobum. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ [].
ABBREVIATION : TOXDIV SYNONYMS : Rhus diversiloba Torr. & A. Gray [46] NRCS PLANT CODE : TODI COMMON NAMES : Pacific poison-oak Pacific poison oak TAXONOMY : The currently accepted scientific name of Pacific poison-oak is Toxicodendron diversilobum (Torr. & Gray) E. Greene (Anacardiacae) [31]. Pacific poison-oak and western poison-ivy (Toxicodendron rydbergii) hybridize in the Columbia River Gorge area [38]. LIFE FORM : Vine, Shrub FEDERAL LEGAL STATUS : NO-ENTRY OTHER STATUS : NO-ENTRY

DISTRIBUTION AND OCCURRENCE

SPECIES: Toxicodendron diversilobum
GENERAL DISTRIBUTION : Pacific poison-oak is distributed from Baja California north to British Columbia [31,45,58].  It occurs west of the Cascade Range in Washington, Oregon, and California [32] and is ubiquitous in California west of the Sierra Nevada and the Mojave Desert [38]. ECOSYSTEMS :    FRES20  Douglas-fir    FRES21  Ponderosa pine    FRES24  Hemlock - Sitka spruce    FRES27  Redwood    FRES28  Western hardwoods    FRES34  Chaparral - mountain shrub STATES :      CA  OR  WA  MEXICO  BC BLM PHYSIOGRAPHIC REGIONS :     1  Northern Pacific Border     2  Cascade Mountains     3  Southern Pacific Border     4  Sierra Mountains KUCHLER PLANT ASSOCIATIONS :    K001  Spruce - cedar - hemlock forest    K002  Cedar - hemlock - Douglas-fir forest    K005  Mixed conifer forest    K006  Redwood forest    K009  Pine - cypress forest    K010  Ponderosa shrub forest    K026  Oregon oakwoods    K028  Mosaic of K002 and K026    K029  California mixed evergreen forest    K030  California oakwoods    K033  Chaparral    K034  Montane chaparral    K035  Coastal sagebrush SAF COVER TYPES :    213  Grand fir    222  Black cottonwood - willow    224  Western hemlock    229  Pacific Douglas-fir    230  Douglas-fir - western hemlock    231  Port Orford-cedar    232  Redwood    233  Oregon white oak    234  Douglas-fir - tanoak - Pacific madrone    235  Cottonwood - willow    243  Sierra Nevada mixed conifer    244  Pacific ponderosa pine - Douglas-fir    245  Pacific ponderosa pine    246  California black oak    247  Jeffrey pine    248  Knobcone pine    249  Canyon live oak    250  Blue oak - Digger pine    255  California coast live oak SRM (RANGELAND) COVER TYPES : NO-ENTRY HABITAT TYPES AND PLANT COMMUNITIES : Pacific poison-oak occurs in mixed evergreen forests [29,30,32,59], woodlands, chaparral, [25,26,27], coastal sage scrub [39], and riparian zones [25,26,27,39,58].  It is the most widespread shrub in California [7]. Holland [33] described a Pacific poison-oak chaparral community type that may be maintained by frequent fire.  Because it is dominated by Pacific poison-oak, little is known of its community composition. Many of the plant species commonly associated with Pacific poison-oak were previously listed under DISTRIBUTION AND OCCURRENCE information.  Other common associates follow, listed by community type. Associates in mixed evergreen forests include Pacific madrone (Arbutus menziesii), sugar pine (Pinus lambertiana), bigleaf maple (Acer macrophyllum), tanoak (Lithocarpus densiflorus), California bay (Umbellularia californica), and chinquapin (Chrysolepsis chrysophylla) [11,17,18,43]. Woodland associates include valley oak (Quercus lobata), interior live oak (Q. wislizenii), Monterey pine (Pinus radiata) [42], Coulter pine (P. coulteri) [9], bigcone Douglas-fir (Pseudotsuga macrocarpa) [8,64], and California walnut (Juglans californica) [48]. Chaparral associates include toyon (Heteromeles arbutifolia), chamise (Adenostoma fasciculatum), and California scrub oak (Quercus dumosa). Coastal sage scrub associates include California sagebrush (Artemisia californica), coyote brush (Baccharis pilularis), and sugar sumac (Rhus ovata) [6,26,27,47,65]. Pacific poison-oak associates in riparian zones include bigleaf maple, California sycamore (Plantus racemosa), white alder (Alnus rhombifolia), [17], boxelder (Acer negundo), willow (Salix spp.), California blackberry (Rubus vitifolius), toyon, and wild grape (Vitis spp.)  [69]. Published classifications naming Pacific poison-oak as a dominant part of the vegetation are: Description and classification of the forests of the upper Illinois    River drainage of southwestern Oregon [1] Preliminary plant associations of the Siskiyou Mountain Province [2] Coast redwood ecological types of southern Monterey County, California [10] Plant communities of Santa Rosa Island, Channel Islands National Park [14] Plant association and management guide: Siuslaw National Forest [29] Plant association and management guide: Willamette National Forest [30] The community composition of California coastal sage scrub [39] Plant associations within the Interior Valleys of the Umpqua River    Basin, Oregon [55] The vascular plant communities of California [59] An introduction to the plant communities of the Santa Ana and San    Jacinto Mountains [65].

MANAGEMENT CONSIDERATIONS

SPECIES: Toxicodendron diversilobum
IMPORTANCE TO LIVESTOCK AND WILDLIFE : Black-tailed deer and all classes of livestock browse Pacific poison-oak [53]. It is the most important black-tailed deer browse in some areas of California [5,6].  Birds eat Pacific poison-oak fruits [53]. PALATABILITY : Pacific poison-oak palatability is rated good to fair for horses and deer; and fair to poor for cattle, sheep, and goats [53]. NUTRITIONAL VALUE : Percent crude protein in Pacific poison-oak foliage collected throughout California averaged 24.2 in March, 20.6 in May, 10.1 in July, and 6.5 in September [5].  Pacific poison-oak is relatively high in phosphorus, sulfur, and calcium as compared to other browse species [24].  The following mineral content (percentage basis) was reported for the foliage [54]:                    Ca     P     K     Mg     S                  1.00   0.23  1.13  0.59   0.19 COVER VALUE : The federally endangered least Bell's vireo uses Pacific poison-oak for nest sites in oak woodlands [25].  Fremont cottonwood (Populus fremontii)/Pacific poison-oak woodlands contribute to bird diversity and density in California [28].  A rare colony of ringtail was found inhabiting a Fremont cottonwood/Pacific poison-oak woodland on the Sacramento River [3]. VALUE FOR REHABILITATION OF DISTURBED SITES : Pacific poison-oak has been recommended for use in restoration projects. Information on propagation and handling methods to "minimize risks" to planting crews is available [23].  Having worked on field crews in the Sierra Nevada foothills, however, this author recommends using native shrubs other than Pacific poison-oak for restoration. OTHER USES AND VALUES : Urushiol has been found to mediate DNA strand scission.  This activity may have application in DNA sequence studies [70]. Native Americans used the stems to make baskets and the sap to cure ringworm [15,60].  Chumash Indians used Pacific poison-oak sap to remove warts, corns, and calluses; to cauterize sores; and to stop bleeding.  They drank a decoction made from Pacific poison-oak roots to treat dysentery [60]. OTHER MANAGEMENT CONSIDERATIONS : Safety/Medical:  The entire Pacific poison-oak plant is covered with oily resin. Human dermatitis results when skin comes in direct contact with the oil, either by touching the plant or touching something that has contacted it, such as clothing or firewood.  Urushiol is the poison present in the oil [46].  Pacific poison-oak does not cause dermatitis in wildlife or livestock, but pets may react to it [53]. (See FIRE MANAGEMENT.) American folklore holds that drinking the milk of Pacific poison-oak-fed goats bolsters the immune system against Pacific poison-oak because the poison is present in the milk in trace amounts.  Drinking the milk probably does not grant immunity, however.  Analysis of milk from does fed a straight Pacific poison-oak diet for 3 days showed no trace of urushiol.  Some urushiol was present in the does' urine, but most was apparently catabolized [40]. Control:  Pacific poison-oak is controlled by glyphosate, triclopyr, or 2,4,5-T. Used alone, 2,4-D is ineffective.  Goats are an effective biological control [40,50]. Other:  Pacific poison-oak vines sometimes kill their support plant by smothering or breaking it [46]. Pacific poison-oak blossoms are a source of good honey [46].

BOTANICAL AND ECOLOGICAL CHARACTERISTICS

SPECIES: Toxicodendron diversilobum
GENERAL BOTANICAL CHARACTERISTICS : Pacific poison-oak is a many-stemmed, deciduous, native shrub or woody vine. Shrubs are erect with stems from 2 to 6 feet (1-2 m) tall.  Vine stems commonly reach 10 to 30 feet (3-10 m), but may be as long as 100 feet (30 m) [22].  As a vine, Pacific poison-oak climbs trees or other support by adventitious roots and/or wedging stems within grooves or crevices of the support [7,22,62].  The bright green leaves have three (sometimes five) round to ovate, diversely lobed or toothed leaflets that usually resemble oak leaves [45,62].  Small flowers occur in leaf axils, with male and female flowers on separate plants [38,53].  The fruits are white drupes [45].  Rhizomes are at or just below the soil surface, and are extensive [46]. RAUNKIAER LIFE FORM :    Phanerophyte    Hemicryptophyte REGENERATION PROCESSES : Pacific poison-oak reproduces vegetatively by sprouting from the rhizomes and root crown after disturbance such as fire or browsing has removed topgrowth [15,44,53].  It also reproduces by layering when vine stems contact the ground [46]. Pacific poison-oak seeds are dispersed by birds [53].  Seedlings occur both before and after fire, suggesting that the seeds do not depend upon fire for scarification.  The seeds have a gummy seedcoat which leaches off very slowly, resulting in delayed germination [37]. Pacific poison-oak is propagated by stem cuttings [23]. SITE CHARACTERISTICS : Pacific poison-oak generally grows in acid soils, and is not limited to any particular soil texture or drainage pattern.  It occurs on well-drained slopes and in riparian zones [1,39,64].  It is found at elevations of less than 5,000 feet (1,524 m) west of the Sierra Nevada, growing on all aspects [45].  In the Siskiyou Mountains it is found at up to 4,400-foot (1,340-m) elevations on steep southern exposures [66]. SUCCESSIONAL STATUS : Facultative Seral Species Pacific poison-oak is a somewhat shade-tolerant species commonly occurring in seral woodland and mixed evergreen forest understories [51,56].  It is considered a climax species on south-slope Douglas-fir forests of the Willamette Valley foothills, Oregon [51].  In climax oak woodland, Pacific poison-oak cover may reach 25 to 50 percent [17]. SEASONAL DEVELOPMENT : Pacific poison-oak leaf buds open from February to March, and stems elongate from March to April [37].  Flowering occurs from March to June [15].  Leaves drop from late July to early October [22], and fruits disperse in summer and fall [37,53].

FIRE ECOLOGY

SPECIES: Toxicodendron diversilobum
FIRE ECOLOGY OR ADAPTATIONS : Pacific poison-oak's primary postfire regeneration strategy is vigorous sprouting from the root crown and/or rhizomes [16,46,68]. Fire is not required for Pacific poison-oak seed germination.  Keeley [37], however, reported a significant (p<0.001) increase in germination when seeds were exposed to charate.  Postfire seedlings probably originate from both soil-stored seed and fresh seed dispersed by birds. POSTFIRE REGENERATION STRATEGY :    Tall shrub, adventitious-bud root crown    Rhizomatous shrub, rhizome in soil    Ground residual colonizer (on-site, initial community)    Secondary colonizer - off-site seed

FIRE EFFECTS

SPECIES: Toxicodendron diversilobum
IMMEDIATE FIRE EFFECT ON PLANT : Fire top-kills Pacific poison-oak [13,16].  Wirtz [68] reported that an October, 1953, wildfire in a coastal sage scrub/grassland community near Berkeley, California, top-killed all Pacific poison-oak present, leaving only large branches and stumps. Rhizomes on the soil surface are probably killed by all but light-severity fire, and shallowly buried rhizomes are probably killed by moderate to severe fire.  More deeply buried rhizomes are probably not killed. DISCUSSION AND QUALIFICATION OF FIRE EFFECT : NO-ENTRY PLANT RESPONSE TO FIRE : Pacific poison-oak sprouts vigorously from the root crown and/or rhizomes after fire [13,15,43,46,52].  It sprouts in the first postfire growing season, and for several years thereafter [13,16,52].  Pacific poison-oak sprouts were noted the September following the July, 1985, Wheeler Fire on the Los Padres National Forest, California.  The wildfire had spread into a riparian zone containing Pacific poison-oak; prefire Pacific poison-oak density was unknown.  By postfire year 3, Pacific poison-oak sprouts dominated most burn plots in the riparian zone [18]. Westman and others [67] estimated that Pacific poison-oak fails to sprout when fire reaction intensity exceeds 200 kcal/sec/sq m.  Their estimate was derived by modelling fire behavior of a backfire set in coastal sage scrub in the Santa Monica Mountains of California, and observing sprouting the following year.  The coastal sage scrub had not burned for 20 to 22 years. Pacific poison-oak also establishes from seed after fire, although this response is not well documented in the literature.  Pacific poison-oak seedlings were observed following site preparation and prescribed burning of an interior live oak-blue oak woodland in Madera County, California. Prefire Pacific poison-oak seedling density was 0 percent; seedling density at postfire year 1 was 42 per 8,712 square feet [20]. Response of vegetation to prescribed burning in a Jeffrey pine-California black oak woodland and a deergrass meadow at Cuyamaca State Park, California provides information on prescribed fire use and postfire response of many mixed-conifer woodland species including Pacific poison-oak. DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : Fire response is probably related to Poison oak's successional role in the plant community.  Dense Pacific poison-oak thickets may develop in chaparral that is control burned several times [12].  Pacific poison-oak may become locally extinct in Douglas-fir forest, however, that is burned every 4 years for 20 years or more [53]. FIRE MANAGEMENT CONSIDERATIONS : Urushiol volatilizes when burned, and human exposure to Pacific poison-oak smoke is extremely hazardous [40].  The smoke often poisons people who think they are immune to the plant [46]. Pacific poison-oak vines are a ladder fuel [61]. Goats can be used as an alternative to prescribed fire for fire hazard reduction at urban-wildland interfaces.  Near Oakland, California, goats were put on a Monterey pine-redgum (Eucalyptus camaldensis) forest with a heavy shrub understory and on an adjacent site where the forest was managed as a fuelbreak and had less shrub cover in the understory.  Goat utilization of Pacific poison-oak was in the fuelbreak 67 percent, somewhat lower than utilization of toyon, California blackberry, and coyote brush. Annual production of Pacific poison-oak biomass before goat browsing in the fuelbreak was 99 kilograms per hectare; it was 33 kilograms per hectare afterwards.  Total biomass of forage species was significantly (p<0.05) reduced [61]. A stocking rate of 600 goats per hectare on the Oakland site broke the vertical live fuel continuity in the dense shrub stand.  Initial goat browsing to reduce biomass and vertical fuel continuity could be followed up by prescribed fire [61].

REFERENCES

SPECIES: Toxicodendron diversilobum
REFERENCES :  1.  Atzet, Thomas. 1979. Description and classification of the forests of        the upper Illinois River drainage of southwestern Oregon. Corvallis, OR:        Oregon State University. 211 p. Dissertation.  [6452]  2.  Atzet, Thomas; Wheeler, David L. 1984. Preliminary plant associations of        the Siskiyou Mountain Province. Portland, OR: U.S. Department of        Agriculture, Forest Service, Pacific Northwest Region. 278 p.  [9351]  3.  Belluomini, Linda; Trapp, Gene R. 1984. Ringtail distribution and        abundance in the Central Valley of California. In: Warner, Richard E.;        Hendrix, Kathleen M., eds. California riparian systems: Ecology,        conservation, and productive management. Berkeley, CA: University of        California Press: 906-914.  [5880]  4.  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]  5.  Bissell, Harold D.; Strong, Helen. 1955. The crude protein variations in        the browse diet of California deer. California Fish and Game. 41(2):        145-155.  [10524]  6.  Biswell, H. H. 1961. Manipulation of chamise brush for deer range        improvement. California Fish and Game. 47(2): 125-144.  [6366]  7.  Bolsinger, Charles L. 1989. Shrubs of California's chaparral,        timberland, and woodland: area, ownership, and stand characteristics.        Res. Bull. PNW-RB-160. Portland, OR: U.S. Department of Agriculture,        Forest Service, Pacific Northwest Experiment Station. 50 p.  [7426]  8.  Bolton, Robert B., Jr.; Vogl, Richard J. 1969. Ecological requirements        of Pseudotsuga macrocarpa in the Santa Ana Mountains, California.        Journal of Forestry. 67: 112-116.  [10807]  9.  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] 10.  Borchert, Mark; Segotta, Daniel; Purser, Michael D. 1988. Coast redwood        ecological types of southern Monterey County, California. Gen. Tech.        Rep. PSW-107. Berkeley, CA: U.S. Department of Agriculture, Forest        Service, Pacific Southwest Forest and Range Experiment Station. 27 p.        [10225] 11.  Bowler, Peter A. 1990. Riparian woodland: an endangered habitat in        southern California. In: Schoenherr, Allan A., ed. Endangered plant        communities of southern California: Proceedings, 15th annual symposium;        1989 October 28; Fullerton, CA. Special Publication No. 3. Claremont,        CA: Southern California Botanists: 80-97.  [21321] 12.  Burcham, L. T. 1974. Fire and chaparral before European settlement. In:        Rosenthal, Murray, ed. Symposium on living with the chaparral:        Proceedings; 1973 March 30-31; Riverside, CA. San Francisco, CA: The        Sierra Club: 101-120.  [4669] 13.  Christensen, Norman L.; Muller, Cornelius H. 1975. Effects of fire on        factors controlling plant growth in Adenostoma chaparral. Ecological        Monographs. 45: 29-55.  [4923] 14.  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.  [18246] 15.  Conrad, C. Eugene. 1987. Common shrubs of chaparral and associated        ecosystems of southern California. Gen. Tech. Rep. PSW-99. Berkeley, CA:        U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest        and Range Experiment Station. 86 p.  [4209] 16.  Cook, Sherburne F., Jr. 1959. The effects of fire on a population of        small rodents. Ecology. 40(1): 102-108.  [230] 17.  Davis, Frank W.; Hickson, Diana E.; Odion, Dennis C. 1988. Composition        of maritime chaparral related to fire history and soil, Burton Mesa,        Santa Barbara County, California. Madrono. 35(3): 169-195.  [6162] 18.  Davis, Frank W.; Keller, Edward A.; Parikh, Anuja; Florsheim, Joan.        1989. Recovery of the chaparral riparian zone after wildfire. In:        Protection, management, and restoration for the 1990's: Proceedings of        the California riparian systems conference; 1988 September 22-24; Davis,        CA. Gen. Tech. Rep. PSW-110. Berkeley, CA: U.S. Department of        Agriculture, Forest Service, Pacific Southwest Forest and Range        Experiment Station: 194-203.  [13883] 19.  Eyre, F. H., ed. 1980. Forest cover types of the United States and        Canada. Washington, DC: Society of American Foresters. 148 p.  [905] 20.  Frost, William E. 1989. The Ellis Ranch project: a case study in        controlled burning. No. 891002. Fresno, CA: California Agricultural        Technology Institute and the San Joaquin Experimental Range. 11 p.        [13817] 21.  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] 22.  Gartner, Barbara L. 1991. Relative growth rates of vines and shrubs of        western poison oak, Toxicodendron diversilobum (Anacardiaceae). American        Journal of Botany. 78(10): 1345-1353.  [16703] 23.  Gartner, Barbara L; Thomas, Donald E. 1988. Vegetative propagation of        poison oak (California). Restoration & Management Notes. 6(1): 48-49.        [5474] 24.  Gordon, Aaron; Sampson, Arthur W. 1939. Composition of common California        foothill plants as a factor in range management. Bull. 627. Berkeley,        CA: University of California, College of Agriculture, Agricultural        Experiment Station. 95 p.  [3864] 25.  Gray, M. Violet; Greaves, James M. 1984. Riparian forest as habitat for        the least Bell's vireo. In: Warner, Richard E.; Hendrix, Kathleen M.,        eds. California riparian systems: Ecology, conservation, and productive        management: Proceedings of a conference; 1981 September 17-19; Davis,        CA. Berkeley, CA: University of California Press: 605-611.  [5862] 26.  Hanes, Ted L. 1976. Vegetation types of the San Gabriel Mountians. 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: 65-76.  [4227] 27.  Hanes, Ted L. 1977. California chaparral. In: Barbour, Michael G.;        Major, Jack, eds. Terrestrial vegetation of California. New York: John        Wiley and Sons: 417-469.  [7216] 28.  Hehnke, Merlin; Stone, Charles P. 1979. Value of riparian vegetation to        avian populations along the Sacramento River Sy. In: Johnson, R. Roy;        McCormick, J. Frank, technical coordinators. Strategies for protection        and management of floodplain wetlands & other riparian ecosystems: Proc.        of the symposium; 1978 December 11-13; Callaway Gardens, GA. General        Technical Report WO-12. Washington, DC: U.S. Department of Agriculture,        Forest Service: 228-235.  [4363] 29.  Hemstrom, Miles A.; Logan, Sheila E. 1986. Plant association and        management guide: Siuslaw National Forest. R6-Ecol 220-1986a. Portland,        OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest        Region. 121 p.  [10321] 30.  Hemstrom, Miles A.; Logan, Sheila E.; Pavlat, Warren. 1987. Plant        association and management guide: Willamette National Forest. R6-Ecol        257-B-86. Portland, OR: U.S. Department of Agriculture, Forest Service,        Pacific Northwest Region. 312 p.  [13402] 31.  Hickman, James C., ed. 1993. The Jepson manual: Higher plants of        California. Berkeley, CA: University of California Press. 1400 p.        [21992] 32.  Hitchcock, C. Leo; Cronquist, Arthur. 1973. Flora of the Pacific        Northwest. Seattle, WA: University of Washington Press. 730 p.  [1168] 33.  Holland, Robert F. 1986. Preliminary descriptions of the terrestrial        natural communities of California. Sacramento, CA: California Department        of Fish and Game. 156 p.  [12756] 37.  Keeley, Jon E. 1987. Role of fire in seed germination of woody taxa in        California chaparral. Ecology. 68(2): 434-443.  [5403] 38.  Kingsbury, John M. 1964. Poisonous plants of the United States and        Canada. Englewood Cliffs, NJ: Prentice-Hall, Inc. 626 p.  [122] 39.  Kirkpatrick, J. B.; Hutchinson, C. F. 1977. The community composition of        Californian coastal sage scrub. Vegetatio. 35(1): 21-33.  [5612] 40.  Kouakou, Brou; Rampersad, David; Rodriguez, Eloy; Brown, Dan L. 1992.        Dairy goats used to clear poison oak do not transfer toxicant to milk.        California Agriculture. 46(3): 4-6.  [19691] 41.  Kuchler, A. W. 1964. United States [Potential natural vegetation of the        conterminous United States]. Special Publication No. 36. New York:        American Geographical Society. 1:3,168,000; colored.  [3455] 42.  McDonald, Philip M.; Laacke, Robert J. 1990. Pinus radiata D. Don        Monterey pine. In: Burns, Russell M.; Honkala, Barbara H., technical        coordinators. Silvics of North America. Volume 1. Conifers. Agric.        Handb. 654. Washington, DC: U.S. Department of Agriculture, Forest        Service: 433-441.  [13401] 43.  McKee, Arthur. 1990. Castanopsis chrysophylla (Dougl.) A. DC.  giant        chinkapin. In: Burns, Russell M.; Honkala, Barbara H., technical        coordinators. Silvics of North America. Vol. 2. Hardwoods. Agric. Handb.        654. Washington, DC: U.S. Department of Agriculture, Forest Service:        234-239.  [13962] 44.  McKell, Cyrus M.; Blaisdell, James P.; Goodin, Joe R., eds. 1972.        Wildland shrubs--their biology and utilization: An international        symposium; 1971 July; Logan, UT. Gen. Tech. Rep. INT-1. Ogden, UT: U.S.        Department of Agriculture, Forest Service, Intermountain Forest and        Range Experiment Station. 494 p.  [1612] 45.  Munz, Philip A. 1974. A flora of southern California. Berkeley, CA:        University of California Press. 1086 p.  [4924] 46.  Pacific Northwest Extension Service. 1983. Poison oak and ivy. PNW 108.        Corvallis, OR; Pullman, WA; Moscow, ID. 2 p.  [6613] 47.  Pase, Charles P. 1982. Californian (coastal) chaparral. In: Brown, David        E., ed.  Biotic communities of the American Southwest--United States and        Mexico. Desert Plants. 4(1-4): 91-94.  [8891] 48.  Quinn, Ronald D. 1990. The status of walnut forests and woodlands        (Juglans californica) in southern California. In: Schoenherr, Allan A.,        ed. Endangered plant communities of southern California: Proceedings,        15th annual symposium; 1989 October 28; Fullerton, CA. Special        Publication No. 3. Claremont, CA: Southern California Botanists: 42-54.        [21319] 49.  Raunkiaer, C. 1934. The life forms of plants and statistical plant        geography. Oxford: Clarendon Press. 632 p.  [2843] 50.  Rice, Carol. 1990. Restoration plays an integral role in fire hazard        reduction plan for the Berkeley Hills Area. Restoration & Management        Notes. 8(2): 125-126.  [13792] 51.  Sabhasri, Sanga ; Ferrell, William K. 1960. Invasion of brush species        into small stand openings in the Douglas-fir forests of the Willamette        Foothills. Northwest Science. 34(3): 77-89.  [8652] 52.  Sampson, Arthur W. 1944. Effect of chaparral burning on soil erosion and        on soil-moisture relations. Ecology. 25(2): 171-191.  [16841] 53.  Sampson, Arthur W.; Jespersen, Beryl S. 1963. California range        brushlands and browse plants. Berkeley, CA: University of California,        Division of Agricultural Sciences, California Agricultural Experiment        Station, Extension Service. 162 p.  [3240] 54.  Scrivner, Jerry H.; Vaughn, Charles E.; Jones, Milton B. 1988. Mineral        concentrations of black-tailed deer diets in California chaparral.        Journal of Wildlife Management. 52(1): 37-40.  [3055] 55.  Smith, Winston Paul. 1985. Plant associations within the interior        valleys of the Umpqua River Basin, Oregon. Journal of Range Management.        38(6): 526-530.  [2179] 56.  Stein, William I. 1980. Oregon white oak. In: Eyre, F. H. ., ed. Forest        cover types of the United States and Canada. Washington, DC: Society of        American Foresters: 110-111.  [9857] 57.  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] 58.  Thilenius, John F. 1968. The Quercus garryana forests of the Willamette        Valley, Oregon. Ecology. 49(6): 1124-1133.  [8765] 59.  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] 60.  Timbrook, Jan. 1990. Ethnobotany of Chumash Indians, California, based        on collections by John P. Harrington. Economic Botany. 44(2): 236-253.        [13777] 61.  Tsiouvaras, C. N.; Havlik, N. A.; Bartolome, J. W. 1989. Effects of        goats on understory vegetation and fire hazard reduction in coastal        forest in California. Forest Science. 35(4): 1125-1131.  [9767] 62.  U.S. Department of Agriculture, Forest Service. 1937. Range plant        handbook. Washington, DC. 532 p.  [2387] 63.  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] 64.  Vogl, Richard J. 1973. Ecology of knobcone pine in the Santa Ana        Mountains, California. Ecological Monographs. 43: 125-143.  [4815] 65.  Vogl, Richard J. 1976. An introduction to the plant communities of the        Santa Ana and San Jacinto Mountains. 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: 77-98.  [4230] 66.  Waring, R. H. 1969. Forest plants of the eastern Siskiyous: their        environment and vegetational distribution. Northwest Science. 43(1):        1-17.  [9047] 67.  Westman, W. E.; O'Leary, J. F.; Malanson, G. P. 1981. The effects of        fire intensity, aspect and substrate on post-fire growth of Californian        coastal sage scrub. In: Margaris, N. S.; Mooney, H. A., eds. Components        of productivity of Mediterranean climate regions--basic and applied        aspects. The Hague, Netherlands: Dr W. Junk Pulishers: 151-179.  [13593] 68.  Wirtz, W. O., II. 1982. Postfire community structure of birds and        rodents in southern California chaparral. 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: 241-246.  [6025] 69.  Zembal, Richard. 1990. Riparian habitat and breeding birds along the        Santa Margarita and Santa Ana Rivers of southern California. In:        Schoenherr, Allan A., ed. Endangered plant communities of southern        California: Proceedings, 15th annual symposium; 1989 October 28;        Fullerton, CA. Special Publication No. 3. Claremont, CA: Southern        California Botanists: 98-114.  [21322] 70.  Wasser, Charles; Silva, F.; Rodriquez, E. 1990. Urushiol components as        mediators in DNA strand scission. Experientia. 46(5): 500-502.  [22399]


FEIS Home Page