Mahonia nervosa

License:

Distribution

Dwarf Oregon-grape occurs west of the Cascade Ranges and the Sierra
Nevada from southern British Columbia through Washington and Oregon to
central California [47].

References:

47. Hitchcock, C. Leo; Cronquist, Arthur. 1973. Flora of the Pacific Northwest. Seattle, WA: University of Washington Press. 730 p. [1168]

Source:

License:

Regional Distribution in the Western United States

This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):

    1 Northern Pacific Border
    2 Cascade Mountains
    3 Southern Pacific Border

Source:

License:

Localities documented in Tropicos sources

Berberis nervosa Pursh:
Canada (North America)
United States (North 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.

References:

Anonymous. 1986. List-Based Rec., Soil Conserv. Serv., U.S.D.A. Database of the U.S.D.A., Beltsville.
Hickman, J. C. 1993. Jepson Man.: Higher Pl. Calif. i–xvii, 1–1400. University of California Press, Berkeley.
Munz, P. A. & D. D. Keck. 1959. Cal. Fl. 1–1681. University of California Press, Berkeley.
Flora of North America Editorial Committee, e. 1997. Magnoliidae and Hamamelidae. 3: i–xxiii, 1–590. In Fl. N. Amer. Oxford University Press, New York.
Whittemore, A. T. 1993. Berberis (Berberidaceae). 20 pp.

Source:

License:

Rights Holder:

Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO 63110 USA

Distribution

B.C.; Calif., Idaho, Oreg., Wash.

Source:

License:

Rights Holder:

Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO, 63110 USA

National Distribution

Canada

Origin: Unknown/Undetermined

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

United States

Origin: Unknown/Undetermined

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

Source:

License:

Rights Holder:

NatureServe

Global Range: Mahonia nervosa ranges from British Columbia, Canada, and south through California, U.S.

Source:

License:

Rights Holder:

NatureServe

Dwarf Oregon-grape is a low-growing rhizomatous evergreen shrub which
typically reaches 4 to 24 inches in height [28,69]. On exceptional
sites, plants may grow to 7 feet (2.1 m) [81]. The simple stems are
ascending to erect and generally occur in loose colonies of several
stems [69,46,71]. Compound leaves are borne in terminal tufts [66,69].
Coarsely serrate to spinose, ovate to lance-ovate or acute leaflets
occur in groups of 7 to 21 [46,69,95]. Leaflets are dark green, thick,
and leathery [71,95]. Yellow flowers are borne in erect clusters or
racemes up to 8 inches (21 cm) in length [66,69,71]. The fruit is a
large, dark blue, globose berry with grayish or whitish bloom
[28,69,71,95]. Berries are 0.3 to 0.4 inch (8-10 mm) in diameter, occur
in clusters [35], and contain a number of black seeds [95].

References:

28. Green, R. N.; Courtin, P. J.; Klinka, K.; [and others]
35. Halverson, Nancy M., compiler. 1986. Major indicator shrubs and herbs on National Forests of western Oregon and southwestern Washington. R6-TM-229. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Region. 180 p. [3233]
46. Hitchcock, C. Leo; Cronquist, Arthur. 1964. Vascular plants of the Pacific Northwest. Part 2: Salicaceae to Saxifragaceae. Seattle, WA: University of Washington Press. 597 p. [1166]
66. Minore, Don. 1972. A classification of forest environments in the South Umpqua Basin. Res. Pap. PNW-129. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 28 p. [1660]
69. Munz, Philip A. 1973. A California flora and supplement. Berkeley, CA: University of California Press. 1905 p. [6155]
71. Ossinger, Mary C. 1983. The Pseudotsuga-Tsuga/Rhododendron community in the northeast Olympic Mountains. Bellingham, WA: Western Washington University. 50 p. Thesis. [11435]
81. Smith, Nevin. 1987. Growing natives: the mahonias, Part II. Fremontia. 15(1): 27-28. [10402]
95. Ahrendt, Leslie Walter Allan. 1961. Berberis and Mahonia. A taxonomic revision. Journal of the Linnean Society of London. 57(369): 1-410. [9098]

Source:

License:

Description

Shrubs , evergreen, 0.1-0.8(-2) m. Stems monomorphic, without short axillary shoots. Bark of 2d-year stems brown or yellow-brown, glabrous. Bud scales (13-)20-44 mm, persistent. Spines absent. Leaves 9-21-foliolate; petioles 2-11 cm. Leaflet blades thin and ± flexible; surfaces abaxially rather dull, smooth, adaxially dull, somewhat glaucous; terminal leaflet stalked, blade 2.9-8.4 × 1.2-4.8 cm, 1.8-3.2 times as long as wide; lateral leaflet blades lance-ovate to ovate, 4-6-veined from base, base rounded to cordate, margins plane, toothed, each with 6-13 teeth 1-2(-3) mm tipped with spines to 1-2.4 × 0.1-0.2 mm, apex acute or broadly acuminate. Inflorescences racemose, dense, 30-70-flowered, 6-17 cm; bracteoles membranous, apex acute, obtuse, or rounded. Flowers: anther filaments without distal pair of recurved lateral teeth. Berries blue, glaucous, oblong-ovoid or globose, 8-11 mm, juicy, solid. 2 n = 56.

Source:

License:

Rights Holder:

Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO, 63110 USA

Diagnostic Description

Synonym

Berberis nervosa Pursh var. mendocinensis Roof; Mahonia nervosa (Pursh) Nuttall; M. nervosa var. mendocinensis (Roof) Roof

Source:

License:

Rights Holder:

Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO, 63110 USA

Habitat

Habitat characteristics

More info for the terms: fern, shrub, vine

Dwarf Oregon-grape occurs across a wide range of habitats in submontane
to montane forests of the Pacific Northwest [35,54]. It is a
characteristic shrub of spruce-fir forests [14] but also occurs in
northern coastal coniferous forests and in redwood, mixed evergreen, and
bottomland forests [30,69,78]. In Pacific silver fir communities, dwarf
Oregon-grape is generally restricted to warm, dry sites. In old-growth
Douglas-fir stands of northwestern Oregon, it reaches greatest abundance
on relatively dry sites [82]. This shrub occurs on dry to fairly moist
sites in western hemlock types but reaches greatest abundance on warmer
sites [42,85]. Dwarf Oregon-grape is also common in the warmer
Port-Orford-cedar communities [3].

Dwarf Oregon-grape commonly grows as scattered, or abundant, individuals
but can dominate the understory of semiopen forests [54]. It frequently
forms "lush carpets" in open meadows bordering coniferous stands [71]
and commonly persists in coastal brushfields created by timber harvest
[33,43,51]. Dwarf Oregon-grape grows well in sun or shade [54,87].

Plant associates: Common overstory associates in addition to those
mentioned above include Pacific yew (Taxus brevifolia), Sitka spruce
(Picea sitchensis), and tanoak (Lithocarpus densiflora)
[2,31,42,74,84,89]. In spruce-fir forests, dwarf Oregon grape grows
with understory species such as twinflower, rhododendron (Rhododendron
spp.), and queencup beadlily (Clintonia uniflora). Beargrass
(Xerophyllum tenax) occurs on drier sites [23]. Common associates in
Douglas-fir or western hemlock forests include oceanspray, trailing
blackberry (Rubus ursinus), red huckleberry (Vaccinium parvifolium),
Alaska huckleberry, salal, Pacific rhododendron, vine maple, broadleaf
starflower (Trientalis latifolia), and mosses such as Kindbergia oregana
[21,32,44,54,67]. Old-growth stands are often characterized by a
depauperate understory [48]. In redwood (Sequoia sempervirens)
communities, western sword fern, salal, Oregon oxalis, and redwood violet
(Viola sempervirens) are common associates [60].

Soils: Dwarf Oregon-grape grows well on a variety of soil types [70]
including coarse, shallow rocky soils, coarse alluvium, or glacial
outwash [39]. Soils are well drained to poorly drained, and dry to
fresh [28,54,70]. Soils are derived from a wide range of parent
material including basalt and metavolcanics, sandstone, siltstone,
diorite, and gabbro [3,7,44,90]. Good growth has been reported on
acidic to moderately alkaline or even somewhat saline soils [70].

Climate: Dwarf Oregon-grape grows in maritime to submaritime climates.
Growing seasons are fairly long [35]. Some sites experience summer
drought [43].

Elevation: Dwarf Oregon-grape grows at low to middle elevations
[35,90]. In California, it is restricted to sites below 6,000 feet
(1,829 m) [69].

References:

2. Agee, James K.; Kertis, Jane. 1987. Forest types of the North Cascades National Park Service Complex. Canadian Journal of Botany. 65: 1520-1530. [6327]
3. 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]
7. Bailey, Arthur Wesley. 1966. Forest associations and secondary succession in the southern Oregon Coast Range. Corvallis, OR: Oregon State University. 166 p. Thesis. [5786]
14. Clary, Warren P. 1983. Overstory-understory relationships: spruce-fir forests. In: Bartlett, E. T.; Betters, David R., eds. Overstory-understory relationships in Western forests. Western Regional Research Publication No. 1. Fort Collins, CO: Colorado State University Experiment Station: 9-12. [3310]
21. Franklin, Jerry Forest. 1966. Vegetation and soils in the subalpine forests of the southern Washington Cascade Range. Pullman, WA: Washington State University. 132 p. Thesis. [10392]
23. Franklin, Jerry F. 1983. Ecology of noble fir. In: Oliver, Chadwick Dearing; Kenady, Reid M., eds. Proceedings of the biology and management of true fir in the Pacific Northwest symposium; 1981 February 24-26; Seattle-Tacoma, WA. Contribution No. 45. Seattle, WA: University of Washington, College of Forest Resources: 59-69. [7783]
28. Green, R. N.; Courtin, P. J.; Klinka, K.; [and others]
30. Habeck, James R. 1961. The original vegetation of the mid-Willamette Valley, Oregon. Northwest Science. 35: 65-77. [11419]
31. Hall, Frederick C. 1984. Ecoclass coding system for the Pacific Northwest plant associations. R6 Ecol 173-1984. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Region. 83 p. [7650]
32. Halpern, C. B. 1989. Early successional patterns of forest species: interactions of life history traits and disturbance. Ecology. 70(3): 704-720. [6829]
33. Halpern, Charles B.; Franklin, Jerry F. 1989. Understory development in Pseudotsuga forests: multiple paths of succession. In: Ferguson, Dennis E.; Morgan, Penelope; Johnson, Frederic D., compilers. Proceedings--land classifications based on vegetation: applications for resource management; 1987 November 17-19; Moscow, ID. Gen. Tech. Rep. INT-257. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 293-297. [6961]
35. Halverson, Nancy M., compiler. 1986. Major indicator shrubs and herbs on National Forests of western Oregon and southwestern Washington. R6-TM-229. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Region. 180 p. [3233]
39. Christensen, Norman L.; Muller, Cornelius H. 1975. Relative importance of factors controlling germination and seedling survival in Adenostoma chaparral. American Midland Naturalist. 93(1): 71-78. [9689]
42. 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]
43. 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]
44. Hines, William Wester. 1971. Plant communities in the old-growth forests of north coastal Oregon. Corvallis, OR: Oregon State University. 146 p. Thesis. [10399]
48. Huff, Mark Hamilton. 1984. Post-fire succession in the Olympic Mountains, Washington: forest vegetation, fuels, and avifauna. Seattle, WA: University of Washington. 235 p. Dissertation. [9248]
51. Kelpsas, B. R. 1978. Comparative effects of chemical, fire, and machine site preparation in an Oregon coastal brushfield. Corvallis, OR: Oregon State University. 97 p. Thesis. [6986]
54. Klinka, K.; Krajina, V. J.; Ceska, A.; Scagel, A. M. 1989. Indicator plants of coastal British Columbia. Vancouver, BC: University of British Columbia Press. 288 p. [10703]
60. Lenihan, James M. 1990. Forest ass. of Little Lost Man Creek, Humboldt Co., CA: reference-level in the hierarchical structure of old-growth coastal redwood vegetation. Madrono. 37(2): 69-87. [10673]
67. Mitchell, John E. 1983. Overstory-understory relationships: Douglas-fir forests. In: Bartlett, E. T.; Betters, David R., eds. Overstory-understory relationships in western forests. Western Regional Res. Publ. No. 1. Fort Collins, CO: Colorado State University Experiment Station: 27-34. [3314]
69. Munz, Philip A. 1973. A California flora and supplement. Berkeley, CA: University of California Press. 1905 p. [6155]
70. Norton, H. H.; Hunn, E. S.; Martinsen, C. S.; Keely, P. B. 1984. Vegetable food products of the foraging economies of the Pacific Northwest. Ecology of Food and Nutrition. 14(3): 219-228. [10327]
71. Ossinger, Mary C. 1983. The Pseudotsuga-Tsuga/Rhododendron community in the northeast Olympic Mountains. Bellingham, WA: Western Washington University. 50 p. Thesis. [11435]
74. Roberts, Catherine Anne. 1975. Initial plant succession after brown and burn site preparation on an alder-dominated brushfield in the Oregon Coast Range. Corvallis, OR: Oregon State University. 90 p. Thesis. [9786]
78. Sawyer, John O.; Thornburgh, Dale A.; Griffin, James R. 1977. Mixed evergreen forest. In: Barbour, Michael G.; Major, Jack, eds. Terrestrial vegetation of California. New York: John Wiley and Sons: 359-381. [7218]
82. Sonnenfeld, Nancy L. 1987. A guide to the vegetative communities at the Valley of the Giants, Outstanding Natural Area, northwestern Oregon, USA. Arboricultural Journal. 11: 209-225. [7453]
84. Thornburgh, Dale. 1990. Picea breweriana Wats. Brewer spruce. 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: 181-186. [13383]
85. Topik, Christopher; Halverson, Nancy M.; Brockway, Dale G. 1986. Plant association and management guide for the western hemlock zone: Gifford Pichot National Forest. R6-ECOL-230A. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Region. 132 p. [2351]
87. Van Dersal, William R. 1938. Native woody plants of the United States, their erosion-control and wildlife values. Washington, DC: U.S. Department of Agriculture. 362 p. [4240]
89. Waring, R. H. 1969. Forest plants of the eastern Siskiyous: their environment and vegetational distribution. Northwest Science. 43(1): 1-17. [9047]
90. Whittaker, R. H. 1960. Vegetation of the Siskiyou Mountains, Oregon and California. Ecological Monographs. 30(3): 279-338. [6836]

Source:

License:

Key Plant Community Associations

More info for the terms: association, fern, series, succession, vine

Dwarf Oregon-grape is an understory dominant in montane to submontane
coniferous and mixed evergreen forests of the Pacific Northwest.
Oceanspray (Holodiscus discolor), Alaska huckleberry (Vaccinium
alaskaense), salal (Gaultheria shallon), pachistima (Pachistima
myrsinites), western sword fern (Polystichum munitum), Pacific
rhododendron (Rhododendron macrophyllum), Sadler oak (Quercus
sadleriana), twinflower (Linnaea borealis), deerfoot vanillaleaf (Achyls
triphylla), Oregon oxalis (Oxalis oregana), and vine maple (Acer
circinatum) occur as codominants within the forest understory. Dwarf
Oregon-grape is listed as an indicator or dominant in the following
publications:

Forest types of the North Cascades National Park Service Complex [2]
The tanoak series of the Siskiyou region of southwest Oregon (Part 2) [6]
Preliminary plant associations of the Siskiyou Mountain Province [5]
Plant association and management guide for the Pacific silver fir zone:
Gifford Pinchot National Forest [11]
Natural vegetation of Oregon and Washington [24]
Understory development in Pseudotsuga forests: multiple paths of
succession [33]
Forest succession on alluvial landforms of the MacKenzie River Valley,
Oregon [39]
Plant communities in the old-growth forests of north coastal Oregon [44]
Forest ecosystems of Mount Rainier National Park [68]
Mixed evergreen forest [78].

References:

5. 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]
2. Agee, James K.; Kertis, Jane. 1987. Forest types of the North Cascades National Park Service Complex. Canadian Journal of Botany. 65: 1520-1530. [6327]
6. Atzet, Tom; Wheeler, David; Smith, Brad; [and others]
11. Brockway, Dale G.; Topik, Christopher; Hemstrom, Miles A.; Emmingham, William H. 1985. Plant association and management guide for the Pacific silver fir zone: Gifford Pinchot National Forest. R6-Ecol-130a. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Region. 122 p. [525]
24. Franklin, Jerry F.; Dyrness, C. T. 1973. Natural vegetation of Oregon and Washington. Gen. Tech. Rep. PNW-8. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 417 p. [961]
33. Halpern, Charles B.; Franklin, Jerry F. 1989. Understory development in Pseudotsuga forests: multiple paths of succession. In: Ferguson, Dennis E.; Morgan, Penelope; Johnson, Frederic D., compilers. Proceedings--land classifications based on vegetation: applications for resource management; 1987 November 17-19; Moscow, ID. Gen. Tech. Rep. INT-257. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 293-297. [6961]
39. Christensen, Norman L.; Muller, Cornelius H. 1975. Relative importance of factors controlling germination and seedling survival in Adenostoma chaparral. American Midland Naturalist. 93(1): 71-78. [9689]
44. Hines, William Wester. 1971. Plant communities in the old-growth forests of north coastal Oregon. Corvallis, OR: Oregon State University. 146 p. Thesis. [10399]
68. Moir, W. H.; Hobson, F. D.; Hemstrom, M.; Franklin, J. F. 1979. Forest ecosystems of Mount Rainier National Park. In: Linn, Robert M., ed. Proceedings, 1st conference on scientific research in the National Parks: Vol I; 1976 Nov. 9-12; New Orleans, LA. National Park Service Transactions and Proceedings Series No. 5. Washington, DC: U.S. Department of the Interior, National Park Service: 201-207. [1674]
78. Sawyer, John O.; Thornburgh, Dale A.; Griffin, James R. 1977. Mixed evergreen forest. In: Barbour, Michael G.; Major, Jack, eds. Terrestrial vegetation of California. New York: John Wiley and Sons: 359-381. [7218]

Source:

License:

Habitat: Ecosystem

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):

   FRES20 Douglas-fir
   FRES21 Ponderosa pine
   FRES22 Western white pine
   FRES23 Fir - spruce
   FRES24 Hemlock - Sitka spruce
   FRES27 Redwood
   FRES28 Western hardwoods

Source:

License:

Habitat: Cover Types

This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):

   207 Red fir
   211 White fir
   213 Grand fir
   215 Western white pine
   221 Red alder
   224 Western hemlock
   225 Western hemlock - Sitka spruce
   226 Coastal true fir - hemlock
   227 Western redcedar - western hemlock
   228 Western redcedar
   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
   244 Pacific ponderosa - Douglas-fir
   246 California black oak
   247 Jeffrey pine
   249 Canyon live oak

Source:

License:

Habitat: Plant Associations

This species is known to occur in association with the following plant community types (as classified by Küchler 1964):

   K002 Cedar - hemlock - Douglas-fir forest
   K003 Silver fir - Douglas-fir forest
   K005 Mixed conifer forest
   K006 Redwood forest
   K007 Red fir forest
   K013 Cedar - hemlock - pine forest
   K026 Oregon oakwoods
   K029 California mixed evergreen forest
   K030 California oakwoods

Source:

License:

Habitat

Open or shaded woods, often in rocky areas; 0-1800m.

Source:

License:

Rights Holder:

Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO, 63110 USA

Comments: An understory plant in western North American coniferous forests, typically growing only on the western side of the Cascades Range below 2200 m. Relatively shade tolerant and common in second-growth Douglas-fir forests (Vance et al in press).

Source:

License:

Rights Holder:

NatureServe

General Ecology

Fire Management Implications

More info for the term: shrubs

Dwarf Oregon-grape and others shrubs are more likely to dominate early
seral stages after fires of low intensity. Damage or destruction of
underground regenerative structures is more probable after severe fires
and can result in a slow recovery. Shrubs in general are less severely
harmed by fires in early spring or late fall when carbohydrate reserves
are still concentrated in the roots than by fires occurring during
growth periods.

Source:

License:

Site Description

Elevation - 500 feet (152 m).
Parent materials - bedrock was composed of quartz diorite and diorite,
                overlain with glacial till, outwash, and minor
                lacustrine and aeolian deposits.
Soils - mixture of colluvium, loess, and ablation till; loamy with mixed
                gravel throughout.
Climate - marine and cool. no distinct dry season.
                average of 203 frost-frees days per year.

Source:

License:

Fire Management Considerations

More info for the terms: cover, fire intensity, fuel, prescribed fire, severity, shrub, succession

Timber harvest: Dwarf Oregon-grape commonly exhibits dramatic
reductions soon after timber harvest and subsequent slash fires in
western hemlock-western redcedar-Douglas-fir forests of the Cascade
Ranges, but then often undergoes a dramatic recovery [32]. In some
areas, dwarf Oregon-grape cover has tripled during the first 5 years
after logging and slash fires [17]. However, initial recovery may be
fairly slow on some sites [91]. Posttreatment cover is presumably
related to a number of factors including fire intensity and severity,
season of fire, and site characteristics. Dwarf Oregon-grape commonly
reaches greatest abundance during secondary succession [49]. Abundance
peaked at 30 to 40 years after clearcutting, broadcast burning, and
planting in western hemlock-Douglas-fir forests of the western Cascades
[79]. Posttreatment recovery was as follows [79]:

years since treatment
(percent cover)

2 5 10 15 20 30 40 undisturbed old growth

1.88 5.04 4.22 9.48 6.98 22.18 20.97 11.52

Posttreatment response of dwarf Oregon-grape has been documented in a
number of other studies [7,16,17,27,79,91].

Fuels: Many dwarf Oregon-grape communities are characterized by low to
medium fuel levels [4].

Prescribed fire: Prescribed fire in Pacific rhododendron-dwarf
Oregon-grape communities can greatly increase herb and shrub production
[26].

References:

4. Atzet, Thomas; Wheeler, David L. 1982. Historical and ecological perspectives on fire activity in the Klamath Geological Province of the Rogue River and Siskiyou National Forests. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Region. 16 p. [6252]
7. Bailey, Arthur Wesley. 1966. Forest associations and secondary succession in the southern Oregon Coast Range. Corvallis, OR: Oregon State University. 166 p. Thesis. [5786]
16. Dyrness, C. T. 1965. The effect of logging and slash burning on understory vegetation in the H. J. Andrews Experimental Forest. Res. Note PNW-31. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 13 p. [4939]
17. Dyrness, C. T. 1973. Early stages of plant succession following logging and burning in the western Cascades of Oregon. Ecology. 54(1): 57-69. [7345]
26. Garrison, George A.; Smith, Justin G. 1974. Habitat of grazing animals. In: Cramer, Owen P., ed. Environmental effects of forest residues management in the Pacific Northwest: A state-of-knowledge compendium. Gen. Tech. Rep. PNW-24. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station: P-1 to P-10. [7164]
27. Gashwiler, Jay S. 1970. Further study of conifer seed survival in a western Oregon clearcut. Ecology. 51(5): 849-854. [13081]
32. Halpern, C. B. 1989. Early successional patterns of forest species: interactions of life history traits and disturbance. Ecology. 70(3): 704-720. [6829]
49. Ingram, Douglas C. 1931. Vegetative changes and grazing use on Douglas-fir cut-over land. Journal of Agricultural Research. 43(5): 387-417. [8877]
79. Schoonmaker, Peter; McKee, Arthur. 1988. Species composition and diversity during secondary succession of coniferous forests in the western Cascade Mountains of Oregon. Forest Science. 34(4): 960-979. [6214]
91. Yerkes, Vern P. 1960. Occurrence of shrubs and herbaceous vegetation after clear cutting old-growth Douglas-fir. Res. Pap. PNW-34. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 12 p. [8937]

Source:

License:

Broad-scale Impacts of Plant Response to Fire

Recovery of dwarf Oregon-grape after July, 1970 wildfires in North
Cascades National Park was as follows [65]:

1971 1972 1974
freq. cover freq. cover freq. cover

site 1      44        --          40      .1        32        .6
site 2      82.6     1.6          82.6   2.3        82.6     3.4
site 3      90.3      .16         83.9   2.2        83.9     4.9.

References:

65. Miller, Margaret M.; Miller, Joseph W. 1976. Succession after wildfire in the North Cascades National Park complex. In: Proceedings, annual Tall Timbers fire ecology conference: Pacific Northwest; 1974 October 16-17; Portland, OR. No. 15. Tallahassee, FL: Tall Timbers Research Station: 71-83. [6574]

Source:

License:

Plant Response to Fire

More info for the terms: cover, fire intensity, severity

Dwarf Oregon-grape often sprouts from underground rhizomes after
aboveground portions of the plant are killed [74,91]. However, response
varies with fire intensity, severity [33,58], and season. Atzet and
Wheeler [4] noted sprouts after light-severity fires but did not observe
sprouting after moderate-severity fires. Seedling establishment after
fire has not been documented [32] and may be insignificant.

Postfire recovery: Postfire reestablishment and growth of dwarf
Oregon-grape is often rapid [74]. In western Washington, sprouts are
commonly observed soon after fire [53]. Under some circumstances cover
may equal or exceed that of prefire levels within several years [65].
Dwarf Oregon-grape cover 9 years after slash burning near Oakridge,
Oregon, surpassed that of adjacent unburned plots [83].

Dwarf Oregon-grape abundance may not peak until mid- to late seral
stages, particularly after hot fires [32]. Recovery can be slow after
moderate to hot fires that damage or kill portions of underground
rhizomes. Few dwarf Oregon-grape were present by the third growing
season after a moderate fire in coastal British Columbia [58].

References:

4. Atzet, Thomas; Wheeler, David L. 1982. Historical and ecological perspectives on fire activity in the Klamath Geological Province of the Rogue River and Siskiyou National Forests. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Region. 16 p. [6252]
32. Halpern, C. B. 1989. Early successional patterns of forest species: interactions of life history traits and disturbance. Ecology. 70(3): 704-720. [6829]
33. Halpern, Charles B.; Franklin, Jerry F. 1989. Understory development in Pseudotsuga forests: multiple paths of succession. In: Ferguson, Dennis E.; Morgan, Penelope; Johnson, Frederic D., compilers. Proceedings--land classifications based on vegetation: applications for resource management; 1987 November 17-19; Moscow, ID. Gen. Tech. Rep. INT-257. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 293-297. [6961]
53. Kienholz, Raymond. 1929. Revegetation after logging and burning in the Douglas-fir region of western Washington. Illinois State Academy of Science. 21: 94-108. [8764]
58. Lafferty, R. R. 1972. Regeneration and plant succession as related to fire intensity on clear-cut logged areas in coastal cedar-hemlock type: an interim report. Internal Report BC-33. Victoria, BC: Department of the Environment, Canadian Forestry Service, Pacific Forest Research Centre. Unpublished report on file with: U.S. Department of Agriculture, Forest Service, Intermountain Research Station, Fire Sciences Lab, Missoula, MT. 129 p. [9985]
65. Miller, Margaret M.; Miller, Joseph W. 1976. Succession after wildfire in the North Cascades National Park complex. In: Proceedings, annual Tall Timbers fire ecology conference: Pacific Northwest; 1974 October 16-17; Portland, OR. No. 15. Tallahassee, FL: Tall Timbers Research Station: 71-83. [6574]
74. Roberts, Catherine Anne. 1975. Initial plant succession after brown and burn site preparation on an alder-dominated brushfield in the Oregon Coast Range. Corvallis, OR: Oregon State University. 90 p. Thesis. [9786]
83. Steen, Harold K. 1966. Vegetation following slash fires in one western Oregon locality. Northwest Science. 40(3): 113-120. [5671]
91. Yerkes, Vern P. 1960. Occurrence of shrubs and herbaceous vegetation after clear cutting old-growth Douglas-fir. Res. Pap. PNW-34. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 12 p. [8937]

Source:

License:

Post-fire Regeneration

More info for the terms: rhizome, shrub

Rhizomatous shrub, rhizome in soil

Source:

License:

Fire Ecology

Dwarf Oregon-grape persists in closed forest stands with
long fire-free intervals. However, as a residual survivor, it is also
well-adapted to a regime of "relatively frequent surface fires" such as
those common in certain Douglas-fir-western hemlock/dwarf Oregon-grape
types of Oregon [43]. Fire intervals in Douglas-fir-western hemlock
forest inhabited by dwarf Oregon-grape commonly range from 137 to 320
years [1,71]. Fire intervals in other forest types occupied by dwarf
Oregon-grape have been estimated as follows in Desolation Peaks,
Washington [1]:

      ponderosa pine-Douglas-fir          52 years
      lodgepole pine-Douglas-fir          76 years
      Douglas-fir-grand fir               93 years
      Douglas-fir-Pacific silver fir      108 years

Fire can produce gaps in old-growth redwood forests which are conducive
to dwarf Oregon-grape growth [60].

Dwarf Oregon-grape commonly sprouts and grows vigorously after fire [74].
Reestablishment through seed may occur, although vegetative regeneration
is the dominant mode of postfire establishment [32].

References:

1. Agee, James K.; Finney, Mark; DeGouvenain, Roland. 1990. Forest fire history of Desolation Peak, Washington. Canadian Journal of Forest Research. 20: 350-356. [11035]
32. Halpern, C. B. 1989. Early successional patterns of forest species: interactions of life history traits and disturbance. Ecology. 70(3): 704-720. [6829]
43. 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]
60. Lenihan, James M. 1990. Forest ass. of Little Lost Man Creek, Humboldt Co., CA: reference-level in the hierarchical structure of old-growth coastal redwood vegetation. Madrono. 37(2): 69-87. [10673]
71. Ossinger, Mary C. 1983. The Pseudotsuga-Tsuga/Rhododendron community in the northeast Olympic Mountains. Bellingham, WA: Western Washington University. 50 p. Thesis. [11435]
74. Roberts, Catherine Anne. 1975. Initial plant succession after brown and burn site preparation on an alder-dominated brushfield in the Oregon Coast Range. Corvallis, OR: Oregon State University. 90 p. Thesis. [9786]

Source:

License:

Successional Status

More info for the terms: climax, cover, eruption, succession

Dwarf Oregon-grape is an important component of both seral and climax
communities of the Pacific Northwest. It occurs in recent clearcuts as
well as in stands 300 to 600 years or older [20,82]. It is a woody
survivor or residual colonizer, generally increasing dramatically after
low intensity disturbances such as light fires [32,91]. It commonly
persists on cutover [54] or lightly burned sites. Residual survivors
sprouted soon after the eruption of Mount St. Helens [34] and were
particularly evident in protected microsites such as near the bases or
rootwads of trees. The intensity of disturbance, and of fires in
particular, exerts a great influence on dwarf Oregon-grape [33,58]. In
many areas, it codominates a site soon after light-severity disturbance
but may decline in early seral stages when it is overtopped by rapidly
growing conifer seedlings [33,49].

Annuals and weedy invaders commonly dominate early seral stages where
disturbance has been intense [58]. Fireweed and wood groundsel (Senecio
sylvaticus) assume dominance during the first 1 to 3 years on many
intensely disturbed sites [71]. Perennials such as dwarf Oregon-grape
may not become prominent on intensely burned sites until midsuccessional
stages. In some areas, 30 to 40 years or more may be required before
maximum abundance of dwarf Oregon-grape is reached [79]. It does not
attain maximum cover until later seral stages in many western
redcedar-western hemlock-Douglas-fir forests of thge Cascade Ranges of
Oregon and Washington [18,49].

Dwarf Oregon-grape can assume importance in shrub-dominated stages which
develop 4 to 5 years after disturbance in western hemlock forests of the
Pacific Northwest [24], and can achieve peak abundance within 5 to 10
years after fire in many parts of this region [32]. In the central
Oregon Coast Ranges, is exhibits rapid regrowth and shares understory
dominance in 7- to 50-year-old forests [7].

Dwarf Oregon-grape is tolerant of shade and can complete its life cycle
even in dense forests of the Pacific Northwest [73]. In the Coast
Ranges of central Oregon, it dominates many old-growth western
hemlock-western redcedar forest understories [7]. It is also an
important component of many climatic or topoedaphic climax western
hemlock communities [4,38,39]. Many seral Douglas-fir/dwarf
Oregon-grape communities ultimately give rise to climax western hemlock
types [38,39] as Douglas-fir declines late in succession [7]. Late
seral Douglas-fir/vine maple-dwarf Oregon-grape communities become
climax western hemlock-Pacific rhododendron-dwarf Oregon-grape
communities [24].

References:

20. Fonda, R. W. 1979. Fire resilient forests of Douglas-fir in Olympic National Park: a hypothesis. In: Linn, Robert M., ed. Proceedings, 1st conference on scientific research in the National Parks, Vol. 2; 1976 November 9-12; New Orleans, LA. NPS Transactions and Proceedings No. 5. Washington, DC: U.S. Department of the Interior, National Park Service: 1239-1242. [6698]
4. Atzet, Thomas; Wheeler, David L. 1982. Historical and ecological perspectives on fire activity in the Klamath Geological Province of the Rogue River and Siskiyou National Forests. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Region. 16 p. [6252]
7. Bailey, Arthur Wesley. 1966. Forest associations and secondary succession in the southern Oregon Coast Range. Corvallis, OR: Oregon State University. 166 p. Thesis. [5786]
18. Dyrness, C. T.; Franklin, J. F.; Moir, W. H. 1974. A preliminary classification of forest communities in the central portion of the western Cascades in Oregon. Bulletin No. 4. Seattle, WA: University of Washington, Ecosystem Analysis Studies, Coniferous Forest Biome. 123 p. [8480]
24. Franklin, Jerry F.; Dyrness, C. T. 1973. Natural vegetation of Oregon and Washington. Gen. Tech. Rep. PNW-8. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 417 p. [961]
32. Halpern, C. B. 1989. Early successional patterns of forest species: interactions of life history traits and disturbance. Ecology. 70(3): 704-720. [6829]
33. Halpern, Charles B.; Franklin, Jerry F. 1989. Understory development in Pseudotsuga forests: multiple paths of succession. In: Ferguson, Dennis E.; Morgan, Penelope; Johnson, Frederic D., compilers. Proceedings--land classifications based on vegetation: applications for resource management; 1987 November 17-19; Moscow, ID. Gen. Tech. Rep. INT-257. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 293-297. [6961]
34. Halpern, Charles B.; Harmon, Mark E. 1983. Early plant succession on the Muddy River mudflow, Mount St. Helens, Washington. American Midland Naturalist. 110(1): 97-106. [8870]
38. Hawk, Glenn M. 1979. Vegetation mapping and community description of a small western Cascade watershed. Northwest Science. 53(3): 200-212. [8677]
39. Christensen, Norman L.; Muller, Cornelius H. 1975. Relative importance of factors controlling germination and seedling survival in Adenostoma chaparral. American Midland Naturalist. 93(1): 71-78. [9689]
49. Ingram, Douglas C. 1931. Vegetative changes and grazing use on Douglas-fir cut-over land. Journal of Agricultural Research. 43(5): 387-417. [8877]
54. Klinka, K.; Krajina, V. J.; Ceska, A.; Scagel, A. M. 1989. Indicator plants of coastal British Columbia. Vancouver, BC: University of British Columbia Press. 288 p. [10703]
58. Lafferty, R. R. 1972. Regeneration and plant succession as related to fire intensity on clear-cut logged areas in coastal cedar-hemlock type: an interim report. Internal Report BC-33. Victoria, BC: Department of the Environment, Canadian Forestry Service, Pacific Forest Research Centre. Unpublished report on file with: U.S. Department of Agriculture, Forest Service, Intermountain Research Station, Fire Sciences Lab, Missoula, MT. 129 p. [9985]
71. Ossinger, Mary C. 1983. The Pseudotsuga-Tsuga/Rhododendron community in the northeast Olympic Mountains. Bellingham, WA: Western Washington University. 50 p. Thesis. [11435]
73. Roach, A. W. 1952. Phytosociology of the Nash Crater lava flows, Linn County, Oregon. Ecological Monographs. 22: 169-193. [8759]
79. Schoonmaker, Peter; McKee, Arthur. 1988. Species composition and diversity during secondary succession of coniferous forests in the western Cascade Mountains of Oregon. Forest Science. 34(4): 960-979. [6214]
82. Sonnenfeld, Nancy L. 1987. A guide to the vegetative communities at the Valley of the Giants, Outstanding Natural Area, northwestern Oregon, USA. Arboricultural Journal. 11: 209-225. [7453]
91. Yerkes, Vern P. 1960. Occurrence of shrubs and herbaceous vegetation after clear cutting old-growth Douglas-fir. Res. Pap. PNW-34. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 12 p. [8937]

Source:

License:

Regeneration Processes

More info for the terms: layering, natural

Dwarf Oregon-grape can reproduce from seed or by vegetative means.

Seed: Seed of most Oregon-grapes exhibit internal dormancy and require
cold stratification for germination. However, in certain laboratory
tests, dwarf Oregon-grape seed did not germinate after 90 days of cold
stratification [75]. Results of other studies indicate that seed will
germinate if sown immediately or if stratified and planted in the spring
[15]. Maximum germination capacity in laboratory tests was estimated at
77 percent [75]. Under natural conditions, seeds of most species within
the genus germinate during the spring [15]. The role of sexual
reproduction on disturbed sites is poorly known [32].

Vegetative regeneration: Dwarf Oregon-grape is rhizomatous [47] and
gradually expands laterally in the absence of disturbance. Layering has
also been reported [15]. Plants generally sprout from rhizomes or
"creeping rootstocks" after aboveground portions of the plant are
destroyed [47,74,87,91]. Vegetative regeneration appears to be the
dominant mode of regeneration after fire or other disturbances [32].

References:

15. Durand, Herbert K. 1972. Texas mahonia - a neglected economic plant. Economic Botany. 26(4): 319-325. [10483]
32. Halpern, C. B. 1989. Early successional patterns of forest species: interactions of life history traits and disturbance. Ecology. 70(3): 704-720. [6829]
47. Hitchcock, C. Leo; Cronquist, Arthur. 1973. Flora of the Pacific Northwest. Seattle, WA: University of Washington Press. 730 p. [1168]
74. Roberts, Catherine Anne. 1975. Initial plant succession after brown and burn site preparation on an alder-dominated brushfield in the Oregon Coast Range. Corvallis, OR: Oregon State University. 90 p. Thesis. [9786]
75. Rudolf, Paul O. 1974. Berberis L. barberry, mahonia. 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: 247-251. [7423]
87. Van Dersal, William R. 1938. Native woody plants of the United States, their erosion-control and wildlife values. Washington, DC: U.S. Department of Agriculture. 362 p. [4240]
91. Yerkes, Vern P. 1960. Occurrence of shrubs and herbaceous vegetation after clear cutting old-growth Douglas-fir. Res. Pap. PNW-34. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 12 p. [8937]

Source:

License:

Growth Form (according to Raunkiær Life-form classification)

More info for the term: phanerophyte

Phanerophyte

Source:

License:

Life Form

More info for the term: shrub

Shrub

Source:

License:

Immediate Effect of Fire

Dwarf Oregon-grape is moderately damaged by light- to moderate-severity
fires [4]. Underground regenerative structures often survive even if
aboveground portions are consumed by fire [74,91].

References:

4. Atzet, Thomas; Wheeler, David L. 1982. Historical and ecological perspectives on fire activity in the Klamath Geological Province of the Rogue River and Siskiyou National Forests. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Region. 16 p. [6252]
74. Roberts, Catherine Anne. 1975. Initial plant succession after brown and burn site preparation on an alder-dominated brushfield in the Oregon Coast Range. Corvallis, OR: Oregon State University. 90 p. Thesis. [9786]
91. Yerkes, Vern P. 1960. Occurrence of shrubs and herbaceous vegetation after clear cutting old-growth Douglas-fir. Res. Pap. PNW-34. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 12 p. [8937]

Source:

License:

Season/Severity Classification

Plot 6 - May 22, 1969/high
Plot 7 - September 9, 1968/moderate

Source:

License:

Berries and leaves are browsed by ungulates and rodents (Tilford1998). Also, provides significant forage for the white-footed vole in coastal Oregon (Vance et al. in press). This plant aerates and stabilizes soils.

Source:

License:

Rights Holder:

NatureServe

Cyclicity

Phenology

Plants flower in early to late spring. Fruit ripens during July and
August [87]. Generalized flowering and fruiting dates are as follows
[35,46,69,75,95]:

location flowering fruit ripe

            Northwest                March-June            --
            CA                       April-June            --
            OR (300 ft [91 m])       early April       mid-August
            OR (3,250 ft [991 m])    mid-May           late August
            w OR, sw WA              March-June            --
            WA                       May                September

References:

35. Halverson, Nancy M., compiler. 1986. Major indicator shrubs and herbs on National Forests of western Oregon and southwestern Washington. R6-TM-229. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Region. 180 p. [3233]
46. Hitchcock, C. Leo; Cronquist, Arthur. 1964. Vascular plants of the Pacific Northwest. Part 2: Salicaceae to Saxifragaceae. Seattle, WA: University of Washington Press. 597 p. [1166]
69. Munz, Philip A. 1973. A California flora and supplement. Berkeley, CA: University of California Press. 1905 p. [6155]
75. Rudolf, Paul O. 1974. Berberis L. barberry, mahonia. 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: 247-251. [7423]
87. Van Dersal, William R. 1938. Native woody plants of the United States, their erosion-control and wildlife values. Washington, DC: U.S. Department of Agriculture. 362 p. [4240]
95. Ahrendt, Leslie Walter Allan. 1961. Berberis and Mahonia. A taxonomic revision. Journal of the Linnean Society of London. 57(369): 1-410. [9098]

Source:

License:

Flowering/Fruiting

Flowering winter-spring (Mar-Jun).

Source:

License:

Rights Holder:

Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO, 63110 USA

Molecular Biology

Statistics of barcoding coverage: Mahonia nervosa

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Specimens with Barcodes: 1
Species With Barcodes: 1

Source:

http://creativecommons.org/licenses/by/3.0/

License:

Rights Holder:

Barcode of Life Data Systems

Statistics of barcoding coverage: Berberis nervosa

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Specimens with Barcodes: 3
Species With Barcodes: 1

Source:

http://creativecommons.org/licenses/by/3.0/

License:

Rights Holder:

Barcode of Life Data Systems

Conservation Status

National NatureServe Conservation Status

Canada

Rounded National Status Rank: NNR - Unranked

United States

Rounded National Status Rank: NNR - Unranked

Source:

License:

Rights Holder:

NatureServe

NatureServe Conservation Status

Rounded Global Status Rank: G5 - Secure

Reasons: Mahonia nervosa ranges from British Columbia south through California in coniferous forests typically only on the western side of the Cascades Range. It is relatively abundant throughout its range. This species is traded in the medicinal, herbal, and landscaping markets, but to a lesser degree than Mahonia aquifolium, because its roots are relatively smaller. However, it may be threatened by increased demand as it is considered to be interchangeable with Mahonia aquifolium by some sources familiar with the medicinal plants industry.

Source:

License:

Rights Holder:

NatureServe

Threats

Comments: Mahonia species are reportedly used as a substitute for goldenseal (Tilford 1998). Some experts in the medicinal plant industry have suggested that trade is medium to large and demand has increased over the past ten years (Robbins 1999). Thus, although current demand is modest, increased interest is possible. Therefore, trends in commercial interest and collecting activities should be monitored even though it is relatively common in its native range. This species is traded in the medicinal, herbal, and landscaping markets, however it may be less viable for large-scale commercial harvest than Mahonia aquifolium because its roots are relatively smaller (Vance et al. in press). Disturbance reduces this species' ability to spread through rhizomes (Vance et al. in press). See Vance et al. (in press) for suggested guidelines for sustainable harvesting techniques.

Source:

License:

Rights Holder:

NatureServe

Management

Management considerations

More info for the terms: fern, frequency

Timber harvest: Dwarf Oregon-grape commonly persists on cutover sites
[54,58]. In many parts of British Columbia and the Pacific Northwest, it
assumes prominence in brushfields made up of such species as salal,
bracken fern (Pteridium aquilinum), blackberries and raspberries (Rubus
spp.), fireweed (Epilobium angustifolium), huckleberries (Vaccinium
spp.), and willows (Salix spp.) [43,54]. Brushfield species may compete
with conifer regeneration in some locations [43].

Biomass: The green weight of dwarf Oregon-grape has been estimated at
130 pounds per acre (145 kg/ha) in certain western hemlock types of
Oregon [43].

Grazing: Grazing by domestic sheep apparently has little effect on
dwarf Oregon-grape [49].

Chemical control: Percent frequency following herbicide applications
combined with mechanical treatment or fire in central coastal Oregon was
as follows [51]:

glyphosate spray and burn spray and crush

pretreatment 13 13 9
posttreatment -- 3 --

The effects of various herbicides on Berberis spp. have been considered
in detail [10].

References:

10. Bovey, Rodney W. 1977. Response of selected woody plants in the United States to herbicides. Agric. Handb. 493. Washington, DC: U.S. Department of Agriculture, Agricultural Research Service. 101 p. [8899]
43. 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]
49. Ingram, Douglas C. 1931. Vegetative changes and grazing use on Douglas-fir cut-over land. Journal of Agricultural Research. 43(5): 387-417. [8877]
51. Kelpsas, B. R. 1978. Comparative effects of chemical, fire, and machine site preparation in an Oregon coastal brushfield. Corvallis, OR: Oregon State University. 97 p. Thesis. [6986]
54. Klinka, K.; Krajina, V. J.; Ceska, A.; Scagel, A. M. 1989. Indicator plants of coastal British Columbia. Vancouver, BC: University of British Columbia Press. 288 p. [10703]
58. Lafferty, R. R. 1972. Regeneration and plant succession as related to fire intensity on clear-cut logged areas in coastal cedar-hemlock type: an interim report. Internal Report BC-33. Victoria, BC: Department of the Environment, Canadian Forestry Service, Pacific Forest Research Centre. Unpublished report on file with: U.S. Department of Agriculture, Forest Service, Intermountain Research Station, Fire Sciences Lab, Missoula, MT. 129 p. [9985]

Source:

License: