Whitethorn ceanothus is not an indicator species for any specific habitat types, but is listed as a "moderate site indicator" in forested communities of the upper montane in the southern and central Sierra Nevada .
Other overstory species commonly associated with whitethorn ceanothus are California black oak (Quercus kelloggii), bitter cherry (Prunus emarginata), and Brewer oak (Q. garryana var. breweri).
Common understory associates of whitethorn ceanothus include: huckleberry oak (Q. vacciniifolia), bush chinquapin (Chrysolepis sempervirens), pinemat manzanita (Arctostaphylos nevadensis), greenleaf manzanita (A. patula), creeping snowberry (Symphoricarpos mollis), redflower currant (Ribes sanguineum), Sierra gooseberry (R. roezlii), California hazel (Corylus cornuta var. californica), deerbrush (Ceanothus integerrimus), prostrate ceanothus (C. prostratus), snowbrush ceanothus (C. velutinus), Sierra mountain misery (Chamaebatia foliolosa), salal (Gaultheria shallon), Pacific rhododendron (Rhododendron macrophyllum), and Saskatoon serviceberry (Amelanchier alnifolia) [21,24,52,60,63,69,98].
Whitethorn ceanothus is a native, evergreen shrub. It has a low-lying, flat-topped growth habit, especially at higher elevations, and generally reaches heights between 2 and 5 feet (0.6-1.5 m). Whitethorn ceanothus can form a continuous ground cover up to 12 feet (3.7 m) in diameter. The many short, rigid, intricately-branched stalks end in sharp spines. The numerous leaves are alternate and distinctly 3-ribbed from the base. They are small, elliptic to egg-shaped, and blunt at the tip. The leaf margins are entire or finely toothed. Flowers are in dense clusters borne on a panicle-like inflorescence. The fruit is a capsule that is slightly crested or horned and somewhat sticky at maturity. It is small, tipped by a threadlike 3-forked appendage, and 3-lobed. Each lobe has a ridge on its back and is 3-celled with each cell bearing 1 hard, round seed or nutlet. [13,25,26,47,73,74, 78,98]
Whitethorn ceanothus has high nitrogen concentrations in its foliage and soil beneath the plant due
to the nitrogen-fixing bacteria Frankia spp., suggesting that it may enhance nitrogen availability
for the surrounding area [75,76].
RAUNKIAER  LIFE FORM:
Whitethorn ceanothus regenerates by seed and vegetative means. Germination from seeds stored in the soil is the primary mode of reproduction for whitethorn ceanothus and generally takes place after fire [40,54]. Prolific sprouting occurs from a lignotuber when damage is done to the top of the plant [40,50]. Whitethorn ceanothus is an obligate sprouter in moderate fuel-consumption burns and a facultative seeder following high fuel-consumption burns .
Pollination: Whitethorn ceanothus is an insect-pollinated species .
Breeding system: Outcrossing is the most common breeding system in Ceanothus spp., with limited autogamy .
Seed production: Ceanothus spp. are prolific seed producers. Thousands of viable seeds can be produced per hectare and remain dormant in the soil and duff layer until disturbance stimulates germination [38,48]. At approximately 4 years of age, whitethorn ceanothus is capable of seed production and reaches a maximum seed load of approximately 4,500 seeds per plant by the age of 20 to 25. Seed production remains high until the plant is senescent, around 40 years of age, or where the plants are inhibited by shade .
Seed dispersal: Whitethorn ceanothus seeds are autochorus, meaning that the main mode of seed dispersal is by the plant itself . The seeds are small and tend to stay where they fall, unless they are carried off by birds, rodents, or ants [22,67]. Ceanothus seeds can also be forcibly ejected from the seed pods when they ripen [22,55].
Seed banking: Because of the large number of seeds produced by whitethorn ceanothus, substantial seed reservoirs exist in the soil and duff layer. The number of seeds in the soil can be expected to vary from year to year depending on the amount of seeds produced and seeds utilized by consumers . Keeley  notes a relationship between the seed bank size and stand age where whitethorn ceanothus is found; the older the stand the larger the seed bank will be. Seed quantities of whitethorn ceanothus combined with littleleaf ceanothus (Ceanothus parvifolius) in over-mature mixed coniferous forests can number up to 1.9 million/acre .
Germination: Whitethorn ceanothus is heavily dependent upon fire for germination . The seeds of whitethorn ceanothus are refractory: they require a heat stimulus alone or in conjunction with other conditions such as cold stratification . Fire, or similar heat treatment, is necessary to crack the seed coat to allow for absorption of water and subsequent germination. Maximum germination occurs with the sequence of fire and a natural stratification period of 10 to 16 weeks [10,17,38,55,80,82]. Whitethorn ceanothus was observed to be germinating profusely on logged areas, perhaps because of heat from insolation .
Fire aids in the germination of seeds but can also destroy them. High intensity or high frequency fires can be detrimental to the seed bank and can result in lower rates of germination [22,68,80,82]. Overall, fire appears to be beneficial in promoting seed numbers, germination, and seedling population [52,68].
The initiation of germination depends on the following: how long the seeds had been dormant; length of time since the last soil disturbance; heat of previous fires; amount of moisture in the soil; persistence of the winter snow pack; soil temperatures; sun exposure; and how deeply the seed was buried .
Seedling establishment/growth: Gratkowski  notes that whitethorn ceanothus seedling establishment is much higher in burned areas than in nonburned areas, where it is almost nonexistent. Biswell  states that seedlings are seldom seen except where there has been fire. Nevertheless, the mortality of Ceanothus spp. seedlings is high during the first 2 postfire years . Environmental factors that affect the growth and survival of these seedlings include insects and other animal browsing, damping-off fungus, soil moisture, exposure, and soil temperature. The first 2 weeks after emergence are the most critical for survival .
Layering is common in whitethorn ceanothus at higher elevations
where the weight of snow forces branches and stems down to the ground . Stump-sprouting from a
lignotuber is also common after the top of the shrub is damaged
Whitethorn ceanothus grows best in open situations [10,17]. Dry, open flats, pine forests, rocky ridges, and washes that have well-drained soils are common sites where whitethorn ceanothus is found [23,47,52,74,98]. Areas that have been burned or logged are very favorable for populations of whitethorn ceanothus [2,27,71]. It can also survive and thrives in the shade of coniferous timber .
Whitethorn ceanothus is known to occur between 2,100 to 11,000 feet (650-3,350 m) in elevation [7,14,23,47,52,74,
Whitethorn ceanothus can be classified as both an early- and late-successional species. It is considered a pioneer species most commonly associated with early successional stages because of its ability to germinate from seed and sprout after disturbance [15,81]. Since whitethorn ceanothus is one of the 1st plants to become established on denuded soils, it has immediate value in soil protection and later serves as a nurse crop for coniferous species . It is possible that whitethorn ceanothus plays an important role in succession by providing a more favorable microclimate of nutrient rich microsites in otherwise harsh growing conditions .
In normal seral conditions whitethorn ceanothus is overtopped and killed by the conifer species that become established in their shade. The brushfields can, however, significantly hinder conifer regeneration and slow the rate of forest succession. If there is repeated fire, whitethorn ceanothus brushfields can become semipermanent communities . Where fire is lacking, it does not establish and populations decrease, and in some cases are eliminated, in the shade of dense tree canopies .
A study by Fernau and others  along the west face of the central Sierra Nevada classified whitethorn
ceanothus as a late-successional species, with populations peaking 26-32 years after disturbance. Findings
published by Minnich  also provide evidence that it is capable of existing in later successional stages.
He states that chronosequences of postsuccession show the establishment of seedlings of whitethorn ceanothus
without fire, apparently from seed caches.
Seasonal development of whitethorn ceanothus begins with emergence and extends through a growing season ranging from 75 to 95 days depending on emergence date and elevation at which it is found. Germination of seedlings begins in late May and June, and they are usually well established by 4 weeks of age. The seedlings were observed to grow at a rate of 0.2 inches (0.5 cm) per week until late August when they began to go dormant. After the 1st growing season whitethorn ceanothus grow very rapidly. In mature whitethorn ceanothus new growth and flower bud swelling occur at the same time, ranging from late May to mid-June depending on elevation. Blossoming is expected about 10 days later and continues for approximately 23 days .
Whitethorn ceanothus flowers between May and August dependent on where location [23,52,74,78]. Seed maturity is reached in the late summer, generally in August or September.
Fire regimes: Whitethorn ceanothus occurs in a mixed fire regime. The presettlement fire regime for communities where whitethorn ceanothus occurs consisted of frequent, low-severity burns and larger stand-replacing fires. Postsettlement, this trend has changed and produced more lethal fires with higher severities and longer intervals . The fire return intervals in the montane chaparral, where whitethorn ceanothus most often occurs, are "probably quite variable" due to the influence of poor growing conditions . Fire in the subalpine forest habitats where whitethorn ceanothus occurs is infrequent due to limited productivity and fuel accumulation in association with short growing season and heavy snow cover .
The following table provides fire return intervals for plant communities and ecosystems where whitethorn ceanothus is important. For further information, see the FEIS review of the dominant species listed below. If you are interested in plant communities or ecosystems that are not listed below, see the complete FEIS Fire Regime Table.
|Community or ecosystem||Dominant species||Fire return interval range (years)|
|California montane chaparral||Ceanothus and/or Arctostaphylos spp.||50-100|
|pinyon-juniper||Pinus-Juniperus spp.||<35 |
|Sierra lodgepole pine*||Pinus contorta var. murrayana||35-200|
|Jeffrey pine||Pinus jeffreyi||5-30|
|Pacific ponderosa pine*||Pinus ponderosa var. ponderosa||1-47 |
|interior ponderosa pine*||Pinus ponderosa var. scopulorum||2-30 [4,5,64]|
|coastal Douglas-fir*||Pseudotsuga menziesii var. menziesii||40-240 [4,72,84]|
|California mixed evergreen||Pseudotsuga menziesii var. menziesii-Lithocarpus densiflorus-Arbutus menziesii||<35|
|canyon live oak||Quercus chrysolepis||<35 to 200 |
|California black oak||Quercus kelloggii||5-30 |
Fire removes most of the above ground whitethorn ceanothus biomass, leaving nitrogen-rich, bare mineral soil. Following fire, patches of whitethorn ceanothus maintain higher amounts of available nitrogen for up to 6 months on both low- and high-intensity burn plots. If these areas continue to have more available nitrogen than other patch types, this long-term effect may enhance tree seedling growth .
The Research Project Summary Plant response to prescribed burning with varying season, weather, and fuel moisture in mixed-conifer forests of California provides information on prescribed fire and postfire response of many plant community species including whitethorn ceanothus.FIRE MANAGEMENT CONSIDERATIONS:
The evolution of whitethorn ceanothus and fire together suggests that the use of prescribed burning is a viable management option in areas to promote whitethorn ceanothus. The use of fire to promote whitethorn ceanothus is suitable because of the fire-stimulated germination of seeds and stump-sprouting in moderate fuel consumption burns. The species adds nitrogen to the soil, possibly enhancing conifer regeneration.
Conversely, overstocked or well-established stands of whitethorn ceanothus add significantly to fuel loading. Extensive stands of whitethorn ceanothus and montane chaparral patches exhibited the greatest mean fire spread/minute and the greatest flame lengths compared to forested types . Snyder  notes that during succession, brush cover is still significant even as the basal area of trees doubles. If these populations persist as noted they could act as ladder fuels, increasing the possibility of a stand replacing fire.
Fuel loading becomes an important factor to recognize when using prescribed fire as a land management tool. The changing fire regime in communities where whitethorn ceanothus becomes established, to infrequent, high-severity fires , suggests that using fire to manage whitethorn ceanothus should be done with caution.
Palatability/nutritional value: Whitethorn ceanothus is an important browse species for deer because of its high crude protein content and palatability [9,22,25,49]. It does not, however, provide sufficient nutrients for optimum growth and development in mule deer and is more valuable when consumed along with other species . It is considered as a poor to fair browse species for livestock such as cattle, domestic sheep, and goats [22,25,73].
No information is available on this topic.
VALUE FOR REHABILITATION OF DISTURBED SITES:
Whitethorn ceanothus has considerable value when used for site amelioration. It is used for erosion control on slopes, terraces, and steep banks [78,89,90]. Whitethorn ceanothus is very important for rehabilitation because of nitrogen-fixing and other soil-building attributes. It is tolerant of severe sites and can play a soil building role on these sites [22,49]. It has successfully been used for these purposes in the Lake Tahoe Basin and Lost Canyon, California [15,19,89,90].
A list of available/potential seed sources can be acquired in the USDA, NRCS Commercial
Sources of Conservation Plant Material, available online .
No information is available on this topic.
OTHER MANAGEMENT CONSIDERATIONS:
There a few main points to consider when managing whitethorn ceanothus. It increases with disturbance and forms very dense, difficult to penetrate brushfields. It is regarded as a very strong competitor that can hinder tree seedling growth and subsequent conifer regeneration [22,57,94]. Whitethorn ceanothus may compete with tree seedlings, but it also provides ongoing nitrogen that may improve the site for conifer establishment and growth after establishment. Soil nitrogen, however, probably becomes most important for tree seedlings after they have cleared the initial hurdle of establishment [49,76]. In the past, herbicide treatments and allowing livestock grazing in whitethorn ceanothus brushfields were used as management options to open the dense shrub canopy. This increased the amount of light reaching the young conifers in the understory and decreased brush competition for soil moisture and nutrients. Initial applications of herbicide resulted in 100% top kill and 20% whitethorn ceanothus mortality with plant mortality reaching 90% after the 3rd application [35,39,40,43,92,103]. A study done by Hobbs and Radosevich  concluded that the control of evergreen woody species such as whitethorn ceanothus in young conifer plantations improved tree seedling growth and in some cases survival.
Conversely, whitethorn ceanothus is valuable as a browse species and if populations decrease, the amount of available forage for wildlife and livestock is also decreased . Prescribed burns are often used in land management to encourage the establishment of whitethorn ceanothus because of its importance as a browse species . It is also beneficial as a nurse plant for conifer and Sierra gooseberry seedlings, providing shade and available nitrogen .
Tappeiner  reported the average size of open-grown whitethorn ceanothus plants on ungrazed, 9-year-old tree plantations in the Sierra Nevada and Klamath Mountains. Average crown diameter was 5.7 feet (1.7 m) and average height was 3.2 feet (.98 m). This information may be useful in predicting shrub development.
1. Adams, Lowell; Stefanescu, Eugene; Dunaway, David J. 1961. Gibberellin and thiourea break seed dormancy in California ceanothus. Res. Note No. 178. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 4 p. 
2. Allen, Barbara H.; Bartolome, James W. 1989. Cattle grazing effects on understory cover and tree growth in mixed conifer clearcuts. Northwest Science. 63(5): 214-220. 
3. Anderson, R. Scott. 1990. Modern pollen rain within and adjacent to two giant sequoia (Sequoiadendron giganteum) groves, Yosemite and Sequoia National Parks, California. Canadian Journal of Forest Research. 20: 1289-1305. 
4. Arno, Stephen F. 2000. Fire in western forest ecosystems. In: Brown, James K.; Smith, Jane Kapler, eds. Wildland fire in ecosystems: Effects of fire on flora. Gen. Tech. Rep. RMRS-GTR-42-vol. 2. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 97-120. 
5. Baisan, Christopher H.; Swetnam, Thomas W. 1990. Fire history on a desert mountain range: Rincon Mountain Wilderness, Arizona, U.S.A. Canadian Journal of Forest Research. 20: 1559-1569. 
6. Barbour, M. G.; Fernau, R. F.; Benayas, J. M. Rey; Jurjavcic, N.; Royce, E. B. 1998. Tree regeneration following clearcut logging in red fir forests of California. Forest Ecology and Management. 104(1-3): 101-111. 
7. Barbour, Michael G. 1988. Californian upland forests and woodlands. In: Barbour, Michael G.; Billings, William Dwight, eds. North American terrestrial vegetation. Cambridge; New York: Cambridge University Press: 131-164. 
8. 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. 
9. 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. 
10. Biswell, H. H.; Buchanan, H.; Gibbens, R. P. 1966. Ecology of the vegetation of a second-growth sequoia forest. Ecology. 47(4): 630-634. 
11. Biswell, Harold H. 1974. Effects of fire on chaparral. In: Kozlowski, T. T.; Ahlgren, C. E., eds. Fire and ecosystems. New York: Academic Press: 321-364. 
12. Bolsinger, Charles L. 1989. California's western juniper and pinyon-juniper woodlands: area, stand characteristics, wood volume, and fenceposts. Res. Bull. PNW-RB-166. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 37 p. 
13. 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. 
14. Botti, Stephen. 1979. Natural, conditional, and prescribed fire management plan. Washington, DC: U.S. Department of the Interior, National Park Service, Yosemite National Park. 51 p. 
15. Bowcutt, Frederica. 1990. Native herbaceous species used in mitigation project in Lake Tahoe basin. Restoration & Management Notes. 8(1): 38. 
16. Brown, James K.; Smith, Jane Kapler, eds. 2000. Wildland fire in ecosystems: Effects of fire on flora. Gen. Tech Rep. RMRS-GRT-42-vol. 2. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 257 p. 
17. Buchanan, Hayle; Biswell, Harold H.; Gibbens, Robert P. 1966. Succession of vegetation in a cut-over Sierra redwood forest. Utah Academy Proceedings. 43(Part 1): 43-48. 
18. Bullock, Scarlett. 1982. Reproductive ecology of Ceanothus cordulatus. Fresno, CA: California State University. 66 p. Thesis. 
19. Chan, Franklin J.; Wong, Raymond M. 1989. Reestablishment of native riparian species at an altered high elevation site. In: Abell, Dana L., technical coordinator. Proceedings of the California riparian systems conference: Protection, management, and restoration for the 1990's; 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: 428-435. 
20. Clark, Edwin C. 1955. Observations on the ecology of a polyhedrosis of the Great Basin tent caterpillar Malacosoma fragilis. Ecology. 36(3): 373-376. 
21. Clark, Harold W. 1932. Breeding range of the Yolla Bolly fox sparrow. The Condor. 34(3): 113-117. 
22. Conard, Susan G.; Jaramillo, Annabelle E.; Cromack, Kermit, Jr.; Rose, Sharon, compilers. 1985. The role of the genus Ceanothus in western forest ecosystems. Gen. Tech. Rep. PNW-182. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 72 p. 
23. Conard, Susan G.; Reed, Merton J. 2003. Ceanothus L. ceanothus, [Online]. In: Bonner, Franklin T., tech. coord. Woody plant seed manual. Washington, DC: U.S. Department of Agriculture, National Tree Seed Laboratory (Producer). Available: http://www.nsl.fs.fed.us/wpsm/index.html [2006, May 3]. 
24. Concilio, Amy; Ma, Siyan; Li, Qinglin; LeMoine, James; Chen, Jiquan; North, Malcolm; Moorhead, Daryl; Jensen, Randy. 2005. Soil respiration response to prescribed burning and thinning in mixed-conifer and hardwood forests. Canadian Journal of Forest Research. 35: 1581-1591. 
25. 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. 
26. Countryman, Clive M. 1982. Physical characteristics of some northern California brush fuels. Gen. Tech. Rep. PSW-61. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 8 p. 
27. Eberlein, Gary P. 1982. Estimating growth of young mountain whitethorn shrubs. PSW-357. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 3 p. 
28. Everett, Richard L.; Meeuwig, Richard O.; Robertson, Joseph H. 1978. Propagation of Nevada shrubs by stem cuttings. Journal of Range Management. 31(6): 426-429. 
29. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. 
30. Fernau, R. F.; Benayas, J. M. Rey; Barbour, M. G. 1998. Early secondary succession following clearcuts in red fir forests of the Sierra Nevada, California. Madrono. 45(2): 131-136. 
31. 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. 
32. Fried, Jeremy S.; Bolsinger, Charles L.; Beardsley, Debby. 2004. Chaparral in southern and central coastal California in the mid-1990s: area, ownership, condition, and change. Resource Bulletin PNW-RB-240. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 86 p. 
33. Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; Lewis, Mont E.; Smith, Dixie R. 1977. Vegetation and environmental features of forest and range ecosystems. Agric. Handb. 475. Washington, DC: U.S. Department of Agriculture, Forest Service. 68 p. 
34. Gordon, Donald T. 1970. Natural regeneration of white and red fir...influence of several factors. Research Paper PSW-58. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 32 p. 
35. Gratkowski, H. J.; Philbrick, J. R. 1965. Repeated aerial spraying and burning to control sclerophyllous brush. Journal of Forestry. 63(12): 919-923. 
36. Gratkowski, H. 1961. Brush problems in southwestern Oregon. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 53 p. 
37. Gratkowski, H. 1961. Brush seedlings after controlled burning of brushlands in southwestern Oregon. Journal of Forestry. 59(12): 885-888. 
38. Gratkowski, H. 1974. Origin of mountain whitethorn brushfields on burns and cuttings in Pacific Northwest forests. Proceedings of the Western Society of Weed Science. 27: 5-8. 
39. Gratkowski, H. 1975. Silvicultural use of herbicides in Pacific Northwest forests. Gen. Tech. Rep. PNW-37. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 44 p. 
40. Gratkowski, H. 1978. Herbicides for shrub and weed control in western Oregon. Gen. Tech. Rep. PNW-77. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 48 p. 
41. Gratkowski, Henry John. 1962. Heat as a factor in germination of seeds of Ceanothus velutinus var. laevigatus T. & G. Corvallis, OR: Oregon State University. 122 p. Dissertation. 
42. Greenlee, John M. 1973. A study of the fire ecology of the Emigrant Basin Primitive Area: Stanislaus National Forest. [Project No. 14]. Sonora, CA: U.S. Department of Agriculture, Forest Service, Stanislaus National Forest, Summit Ranger District, Pinecrest Ranger Station. 64 p. 
43. Greiman, Harley L. 1988. Sheep grazing in conifer plantations. Rangelands. 10(3): 99-101. 
44. Hallin, William E. 1957. Silvical characteristics of Jeffrey pine. Tech. Pap. No. 17. Berkeley, CA: U.S. Department of Agriculture, Forest Service, California Forest and Range Experiment Station. 11 p. 
45. Hartesveldt, Richard J.; Harvey, H. Thomas; Shellhammer, Howard S.; Stecker, Ronald E. 1975. The giant sequoia of the Sierra Nevada. [NPS 120]. Washington, DC: U.S. Department of the Interior, National Park Service. 180 p. 
46. Harvey, H. Thomas; Shellhammer, Howard S.; Stecker, Ronald E. 1980. Giant sequoia ecology: Fire and reproduction. Scientific Monograph Series No. 12. Washington, DC: U.S. Department of the Interior, National Park Service. 182 p. 
47. Hickman, James C., ed. 1993. The Jepson manual: Higher plants of California. Berkeley, CA: University of California Press. 1400 p. 
48. Hobbs, Stephen D.; Radosevich, Steven R. 1987. Nonchemical control of evergreen hardwood competition in new conifer plantations. In: Plumb, Timothy R.; Pillsbury, Norman H., technical coordinators. Proceedings of the symposium on multiple-use management of California's hardwood resources; 1986 November 12-14; San Luis Obispo, CA. Gen. Tech. Rep. PSW-100. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station: 114-121. 
49. Husari, Susan. 1980. Fire ecology of the vegetative habitat types in the Lassen Fire Management Planning Area. In: Swanson, John R.; Johnson, Robert C.; Merrifield, Dave; Dennestan, Alan, compilers. Lassen Fire Management Planning Area: Lassen Volcanic National Park-Caribou Wilderness Unit. Mineral, CA: U.S. Department of the Interior, National Park Service, Lassen Volcanic National Park; Susanville, CA: U.S. Department of Agriculture, Forest Service, Lassen National Forest: Appendix 3: 1-23. 
50. James, Susanne. 1984. Lignotubers and burls--their structure, function and ecological significance in Mediterranean ecosystems. Botanical Review. 50(3): 225-266. 
51. Kartesz, John T.; Meacham, Christopher A. 1999. Synthesis of the North American flora (Windows Version 1.0), [CD-ROM]. Available: North Carolina Botanical Garden. In cooperation with: The Nature Conservancy, Natural Resources Conservation Service, and U.S. Fish and Wildlife Service [2001, January 16]. 
52. Kartesz, John Thomas. 1988. A flora of Nevada. Reno, NV: University of Nevada. 1729 p. [In 2 volumes]. Dissertation. 
53. Kauffman, J. B.; Martin, R. E. 1990. Sprouting shrub response to different seasons and fuel consumption levels of prescribed fire in Sierra Nevada mixed conifer ecosystems. Forest Science. 36(3): 748-764. 
54. Kauffman, John Boone. 1986. The ecological response of the shrub component to prescribed burning in mixed conifer ecosystems. Berkeley, CA: University of California, Berkeley. 235 p. Dissertation. 
55. Keeley, Jon E. 1991. Seed germination and life history syndromes in the California chaparral. The Botanical Review. 57(2): 81-116. 
56. Keeley, Jon E.; Keeley, Sterling C. 1988. Chaparral. In: Barbour, Michael G.; Billings, William Dwight, eds. North American terrestrial vegetation. Cambridge; New York: Cambridge University Press: 165-207. 
57. Kie, John G. 1985. Production of deerbrush and mountain whitethorn related to shrub volume and overstory crown closure. Res. Note PSW-377. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 4 p. 
58. Kie, John G. 1986. Nutritive quality of Ceanothus shrubs in California mixed conifer forest. Journal of Range Management. 39(6): 521-526. 
59. Kilgore, Bruce M. 1971. The role of fire in managing red fir forests. In: Transactions, 36th North American wildlife and natural resources conference; 1971 March 7-10; Portland, OR. Washington, DC: Wildlife Management Institute: 405-416. 
60. Kinloch, Bohun B., Jr.; Scheuner, William. 1990. Pinus lambertiana Dougl. sugar pine. In: Burns, Russell M.; Honkala, Barbara H., tech. coords. Silvics of North America. Volume 1. Conifers. Agricultural Handbook 654. Washington, DC: U.S. Department of Agriculture, Forest Service: 370-379. 
61. Kozlowski, T. T. 2002. Physiological ecology of natural regeneration of harvested and disturbed forest stands: implications for forest management. Forest Ecology and Management. 158(1-3): 195-221. 
62. 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. 
63. Lanini, W. T.; Radosevich, S. R. 1986. Response of three conifer species to site preparation and shrub control. Forest Science. 32(1): 61-77. 
64. Laven, R. D.; Omi, P. N.; Wyant, J. G.; Pinkerton, A. S. 1980. Interpretation of fire scar data from a ponderosa pine ecosystem in the central Rocky Mountains, Colorado. In: Stokes, Marvin A.; Dieterich, John H., tech. coords. Proceedings of the fire history workshop; 1980 October 20-24; Tucson, AZ. Gen. Tech. Rep. RM-81. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station: 46-49. 
65. Ma, Siyan; Chen, Jiquan; Butnor, John R.; North, Malcolm, Euskirchen, Eugene S.; Oakley, Brian. 2005. Biophysical controls on soil respiration in the dominant patch types of an old-growth, mixed-conifer forest. Forest Science. 51(3): 221-232. 
66. Ma, Siyan; Chen, Jiquan; North, Malcolm; Erickson, Heather E.; Bresee, Mary; Le Moine, James. 2004. Short-term effects of experimental burning and thinning on soil respiration in an old-growth, mixed-conifer forest. Environmental Management. 33(Supplement 1): S148-S159. 
67. McArthur, E. Durant. 1989. Breeding systems in shrubs. In: McKell, Cyrus M., ed. The biology and utilization of shrubs. San Diego, CA: Academic Press, Inc.: 341-361. 
68. McDonald, Philip M. 1981. Adaptations of woody shrubs. In: Hobbs, S. D.; Helgerson, O. T., eds. Reforestation of skeletal soils: Proceedings of a workshop; 1981 November 17-19; Medford, OR. Corvallis, OR: Oregon State University, Forest Research Laboratory: 21-29. 
69. Minnich, R. A.; Barbour, M. G.; Burk, J. H.; Sosa-Ramirez, J. 2000. California mixed-conifer forests under unmanaged fire regimes in the Sierra San Pedro Martir, Baja California, Mexico. Journal of Biogeography. 27(1): 105-129. 
70. Minnich, Richard A. 1999. Vegetation, fire regimes, and forest dynamics. In: Miller, P. R.; McBride, J. R., eds. Oxidant air pollution impacts in the montane forests of southern California: a case study of the San Bernardino Mountains. Ecological Studies: Analysis and Synthesis. Vol. 134. New York: Springer-Verlag: 44-80. 
71. Minnich, Richard A.; Franco-Vizcaino, Ernesto. 1997. Protecting vegetation and fire regimes in the Sierra San Pedro Martir of Baja California. Fremontia. 25(3): 13-21. 
72. Morrison, Peter H.; Swanson, Frederick J. 1990. Fire history and pattern in a Cascade Range landscape. Gen. Tech. Rep. PNW-GTR-254. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 77 p. 
73. Mozingo, Hugh N. 1987. Shrubs of the Great Basin: A natural history. Reno, NV: University of Nevada Press. 342 p. 
74. Munz, Philip A. 1974. A flora of southern California. Berkeley, CA: University of California Press. 1086 p. 
75. North, Malcolm; Oakley, Brian; Chen, Jiquan; Erickson, Heather; Gray, Andrew; Izzo, Antonio; Johnson, Dale; Ma, Siyan; Marra, Jim; Meyer, Marc; Purcell, Kathryn; Rambo, Tom; Rizzo, Dave; Roath, Brent; Schowalter, Tim. 2002. Vegetation and ecological characteristics of mixed-conifer and red fir forests at the Teakettle Experimental Forest. Gen. Tech. Rep. PSW-GTR-186. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 52 p. 
76. Oakley, Brian B.; North, Malcolm P.; Franklin, Jerry F. 2003. The effects of fire on soil nitrogen associated with patches of the actinorhizal shrub Ceanothus cordulatus. Plant and Soil. 254: 35-46. 
77. Paysen, Timothy E.; Ansley, R. James; Brown, James K.; Gottfried, Gerald J.; Haase, Sally M.; Harrington, Michael G.; Narog, Marcia G.; Sackett, Stephen S.; Wilson, Ruth C. 2000. Fire in western shrubland, woodland, and grassland ecosystems. In: Brown, James K.; Smith, Jane Kapler, eds. Wildland fire in ecosystems: Effects of fire on flora. Gen. Tech. Rep. RMRS-GTR-42-volume 2. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 121-159. 
78. Post, R. L. 1989. Mountain whitethorn (Ceanothus cordulatus). Fact Sheet 89-64. Reno, NV: University of Nevada, College of Agriculture, Nevada Cooperative Extension. 2p. 
79. Potter, Donald A. 1998. Forested communities of the upper montane in the central and southern Sierra Nevada. Gen. Tech. Rep. PSW-GTR-169. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 319 p. 
80. Quick, Clarence R. 1935. Notes on the germination of ceanothus seeds. Madrono. 3: 135-140. 
81. Quick, Clarence R. 1944. Effects of snowbrush on the growth of Sierra gooseberry. Journal of Forestry. 42: 827-832. 
82. Quick, Clarence R.; Quick, Alice S. 1961. Germination of ceanothus seeds. Madrono. 16: 23-30. 
83. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. 
84. Ripple, William J. 1994. Historic spatial patterns of old forests in western Oregon. Journal of Forestry. 92(11): 45-49. 
85. Robinson, Cyril S. 1937. Plants eaten by California mule deer on the Los Padres National Forest. Journal of Forestry. 35(3): 285-292. 
86. Schimke, Harry E.; Green, Lisle R. 1970. Prescribed fire for maintaining fuel-breaks in the central Sierra Nevada. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 9 p. 
87. Shiflet, Thomas N., ed. 1994. Rangeland cover types of the United States. Denver, CO: Society for Range Management. 152 p. 
88. Skinner, Carl N.; Chang, Chi-ru. 1996. Fire regimes, past and present. In: Status of the Sierra Nevada. Sierra Nevada Ecosystem Project: Final report to Congress. Volume II: Assessments and scientific basis for management options. Wildland Resources Center Report No. 37. Davis, CA: University of California, Centers for Water and Wildland Resources: 1041-1069. 
89. Slayback, Robert D. 1987. Vegetative solutions to erosion control in the Tahoe Basin (California). Restoration & Management Notes. 5(2): 102-103. 
90. Slayback, Robert D.; Clary, Raymond F., Jr. 1988. Vegetative solutions to erosion control in the Tahoe Basin. In: Rieger, John P.; Williams, Bradford K., eds. Proceedings of the second native plant revegetation symposium; 1987 April 15-18; San Diego, CA. Madison, WI: University of Wisconsin Arboretum, Society for Ecological Restoration & Management: 66-69. 
91. Snyder, Bill. 1996. Future fire hazard--implications of site preparation, planting and release decisions. In: Proceedings, 17th annual forest vegetation management conference; 1996 January 16-18; Redding, CA. [Redding, CA]: [Forest Vegetation Management Conference]: 133-136. 
92. Stewart, R. E. 1978. Site preparation. In: Cleary, Brian D.; Greaves, Robert D.; Hermann, Richard K., eds. Regenerating Oregon's forests: A guide for the regeneration forester. Corvallis, OR: Oregon State University Extension Service: 99-129. 
93. Stickney, Peter F. 1989. FEIS postfire regeneration workshop--April 12: Seral origin of species comprising secondary plant succession in Northern Rocky Mountain forests. 10 p. Unpublished draft on file at: U.S. Department of Agriculture, Forest Service, Intermountain Research Station, Fire Sciences Laboratory, Missoula, MT. 
94. Strothmann, R. O.; Roy, Douglass F. 1984. Regeneration of Douglas-fir in the Klamath Mountains Region, California and Oregon. Gen. Tech. Rep. PSW-81. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 35 p. 
95. Tappeiner, John C., II. 1981. Estimating potential hardwoods and shrub cover and plantation development. In: Hobbs, S. D; Helgerson, O. T., eds. Reforestation of skeletal soils: Proceedings of a workshop; 1981 November 17-19; Medford, OR. Corvallis, OR: Oregon State University, Forest Research Laboratory: 97-101. 
96. Teipner, Cynthia Lea; Garton, Edward O.; Nelson, Lewis, Jr. 1983. Pocket gophers in forest ecosystems. Gen. Tech. Rep. INT-154. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 53 p. 
97. Tevis, Lloyd, Jr. 1952. Autumn foods of chipmunks and golden-mantled ground squirrels in the northern Sierra Nevada. Journal of Mammalogy. 33(2): 198-205. 
98. U.S. Department of Agriculture, Forest Service. 1937. Range plant handbook. Washington, DC. 532 p. 
99. U.S. Department of Agriculture, Natural Resources Conservation Service, Tucson Plant Materials Center. 2001. Commercial sources of conservation plant materials, [Online]. Available: http://plant-materials.nrcs.usda.gov/pubs/azpmsarseedlist0501.pdf [2003, August 25]. 
100. U.S. Department of Agriculture, Natural Resources Conservation Service. 2006. PLANTS database (2006), [Online]. Available: http://plants.usda.gov/. 
101. van Wagtendonk, Jan W.; Botti, Stephen J. 1984. Modeling behavior of prescribed fires in Yosemite National Park. Journal of Forestry. 82(8): 479-484. 
102. Vankat, John L.; Major, Jack. 1978. Vegetation changes in Sequoia National Park, California. Journal of Biogeography. 5: 377-402. 
103. Washington State Cooperative Extension Service. 1982. Herbicides in forestry. Pullman, WA: Washington State University, College of Agriculture, Cooperative Extension Service. 13 p. 
104. Weatherspoon, C. Phillip. 1986. Silvics of giant sequoia. In: Weatherspoon, C. Phillip; Iwamoto, Y. Robert; Piirto, Douglas D., technical coordinators. Proceedings of the workshop on management of giant sequoia; 1985 May 24-25; Reedley, CA. Gen. Tech. Rep. PSW-95. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station: 4-10. 
105. Williams, Daniel F.; Verner, Jared; Sakal, Howard F.; Waters, Jeffrey R. 1992. General biology of major prey species of the California spotted owl. In: Verner, Jared; McKelvey, Kevin S.; Noon, Barry R.; Gutierrez, R. J.; Gould, Gordon I., Jr.; Beck, Thomas W., tech. coords. The California spotted owl: a technical assessment of its current status. Gen. Tech. Rep. PSW-GTR-133. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station: 207-221. 
FEIS Home Page