SPECIES: Ceanothus cuneatus
© Michael W. Tuma
Ceanothus cuneatus var. cuneatus (buckbrush)
Ceanothus cuneatus var. fascicularis (McMinn) Hoover (sedgeleaf buckbrush) [55,58]
Ceanothus cuneatus var. rigidus (Nutt.) Hoover (Monterey ceanothus) [55,58]
Hybrids: Ceanothus distribution shares a wide range of habitats and
distributions with other Ceanothus species and is thought to hybridize
frequently [55,78]. Several hybrids are recognized in older floras.
Current floras do not recognize any of these hybrids as separate species.
FEDERAL LEGAL STATUS:
Plants database provides a distributional
map of Wedgeleaf ceanothus and its infrataxa.
FRES21 Ponderosa pine
FRES28 Western hardwoods
FRES34 Chaparral-mountain shrub
STATES/PROVINCES: (key to state/province abbreviations)
In California wedgeleaf ceanothus is the dominant shrub species in the ceanothus chaparral vegetation type. Shrub species that may associate with wedgeleaf ceanothus include chamise (Adenostoma fasciculatum), hoaryleaf ceanothus (Ceanothus crassifolius), hairy ceanothus (C. oliganthus), blueblossom (C. thyrsiflorus), Nuttall's scrub oak (Q. dumosa), toyon (Heteromeles arbutifolia), and sugar sumac (Rhus ovata) .
Chamise chaparral is the most common type of chaparral in California occurring in the north and central Coast Ranges, Sierra Nevada foothills, southern California and northern Baja mountain ranges. This type of chaparral is usually dominated by chamise, although in many stands, wedgeleaf ceanothus codominates with chamise and/or whiteleaf manzanita (Arctostaphylos viscida) . Stands where chamise and wedgeleaf ceanothus codominate are sometimes referred to as mixed chaparral. Species that associate with wedgeleaf ceanothus in this cover type include trees such as blue oak (Q. douglasii) and California buckeye (Aesculus californica), shrubs such as red shank (Adenostoma sparsifolium), Nuttall's scrub oak, birchleaf mountain-mahogany (Cercocarpus betuloides), laurel sumac (Malosma laurina), white and black sage (Salvia mellifera, S. apiana), sugar sumac, Our Lord's candle (Yucca whipplei), and herbs such as giant wildrye (Leymus condensatus), and Eastern Mojave buckwheat (Eriogonum fasciculatum) [8,18,52,74].
The most diverse community where wedgeleaf ceanothus frequently occurs in is the montane chaparral of the lower elevations and xeric sites of the Cascade, Klamath, and Siskiyou mountains of southwestern Oregon and northern California, the Transverse and Peninsular ranges of southern California, and the Sierra San Pedro Mártir of northern Baja. Habitat types in this category are foothill woodlands, and mixed coniferous forest. Generally this cover type refers to occurrences of wedgeleaf ceanothus found in the understory of transmontane forested slopes of Jeffrey pine (Pinus jeffreyi) and gray pine (P. sabiniana) in California, and Pacific ponderosa pine (P. ponderosa var. ponderosa) and oak woodlands of California and Oregon. Characteristic species that associate with wedgeleaf ceanothus in this cover type include trees such as Oregon white oak (Q. garryana), blue oak, California black oak (Q. kelloggii), California shrub live oak (Q. turbinella var. californica), valley oak (Q. lobata), leather oak (Q. durata), interior live oak (Q. wislizenii), coast live oak (Q. agrifolia), canyon live oak (Q. chrysolepis), and California buckeye. Shrubs include whiteleaf manzanita, bigberry manzanita (Arctostaphylos glauca), yerba santa (Eriodictyon californicum), eastern redbud (Cercis canadensis), pointleaf manzanita (A. pungens), Klamath plum (Prunus subcordata), California buckthorn (Frangula californica ssp. cuspidata), common snowberry (Symphoricarpos albus), Mojave ceanothus (Ceanothus greggii var. vestitus), Mohave buckbrush (C. g. var. perplexans), birchleaf mountain-mahogany, thickleaf yerba santa (E. crassifolium), flannelbush (Fremontodendron californicum), California coffeberry (Rhamnus californica), yellowleaf silktassel (Garrya flavescens), and poison-oak (Toxicodendron diversilobum) [19,30,35,52,57,71,84,96]. Also in the montane chaparral, wedgeleaf ceanothus associates with less frequented stands of Baker cypress (Cupressus bakeri) in northern California and southern Oregon [31,101], Tecate cypress (C. forbesii) in southern California and Baja [5,32], and bigcone Douglas-fir (Pseudotsuga macrocarpa) in southern California mountains . In Siskiyou County, California, and on lava flows in eastern Shasta County, California, wedgeleaf ceanothus associates with small populations of western juniper (Juniperus occidentalis) .
The coastal sage scrub habitat type is dominated by California sagebrush (Artemisia californica) and includes wedgeleaf ceanothus in areas in or near low elevation coastal aspects. Other species that may associate with wedgeleaf ceanothus in this cover type include white, black, and purple sage (Salvia leucophylla), California brittlebush (Encelia californica), eastern Mojave buckwheat, and thickleaf yerba santa [34,52,75].
In California small populations of wedgeleaf ceanothus are found on inland dune locations which have minimal soil development. Species that commonly associate with wedgeleaf ceanothus in these communities include coast live oak, chamise, California buckeye, Santa Barbara ceanothus (Ceanothus impressus), California prickly phlox (Leptodactylon californicum), and black sage .
© 2002 Julie Kierstead Nelson
Wedgeleaf ceanothus is a native, perennial, evergreen shrub reaching heights of 3.3 to 11.5 feet (1-3.5 m) tall. The branches are rigid. Leaves are opposite, firm, flat, and 5 to 15 mm long, although considerable differences in leaf size have been observed, which is thought to be driven by water availability . There is evidence that wedgeleaf ceanothus can withdraw nutrients from senescing leaves . For more information see Seedling establishment/growth. Flowers are 5 to 6 mm broad with short erect horns near the top. Fruits are capsules that contain 2 to 3 seeds, round to oblong in shape, and 0.16 inches (4 mm) long [13,35,55,56,58,78,109]. Roots are many branched from a single tap root and can penetrate "deeply" into the soil .
Wedgeleaf ceanothus establishment is generally synchronous after burning so
wedgeleaf ceanothus stands are usually even-aged . Biswell  feels
substantial mortality of wedgeleaf ceanothus begins in stands more than 50 years
RAUNKIAER  LIFE FORM:
Wedgeleaf ceanothus regenerates from seed .
Breeding system: Wedgeleaf ceanothus is monoecious .
Pollination: Wedgeleaf ceanothus is cross-pollinated by insects .
Seed production: Wedgeleaf ceanothus seed production varies yearly .
Seed dispersal: occurs during the spring . The mature capsule bursts upon opening, making an audible pop, and seeds are cast up to a distance of 35 feet (10.7 m) . However, the majority of seeds fall near the parent shrub . Seed casting date and distance depend on phenology of fruit-ripening, temperature, and humidity. Hotter and drier conditions result in further casting which generally occurs during the hot and dry months of July and August .
Seed can also be dispersed by insects. California harvester ants are responsible for caching a considerable amount of wedgeleaf ceanothus seed below ground, which is thought to protect seeds from lethal temperatures during burning .
Seed banking: Seeds of wedgeleaf ceanothus are hard-coated, nearly impermeable, and may lie viable in the ground for many years [22,61]. Viable wedgeleaf ceanothus seed are commonly found buried in soils of chaparral . Exactly how long banked wedgeleaf ceanothus seed can remain viable needs to be investigated.
Germination: occurs during the spring following fire . Wedgeleaf ceanothus seeds require relatively high temperatures during burning (158 to 212 °F (70-100 °C) to facilitate germination . Germination rates are high after fire [33,96] which scarifies wedgeleaf ceanothus seed [87,102]. Heat from fire melts or cracks the cuticle of buried seeds  which is necessary for germination. Sweeney  investigated the effects of fire on seed, and found a majority of wedgeleaf ceanothus seed germinated after being exposed to varying degrees of temperature up to 176 °F (80 °C). The effects of higher temperatures are unknown . Germination rates are significantly (P<.01) enhanced when charate (chemical release from burnt wood) from chamise was used synergistically with heat in germination experiments . The mechanism behind charate-stimulated germination is unknown. While germination is stimulated by burning, in the absence of fire, wedgeleaf ceanothus can germinate in shrub overstory openings [18,22]. In a greenhouse environment germination of wedgeleaf ceanothus was most successful when seeds were planted at depths of 0.5 to 1 inch (1.3-2.5 cm) [2,13].
Seedling establishment/growth: Wedgeleaf ceanothus is widely considered an "obligate seeder" or "fire-recruiter." Regeneration depends almost entirely on germination from seed during postfire conditions [1,20,62,102]. During the spring after burning, varying numbers of wedgeleaf ceanothus seedlings appear. Very high mortality rates are common during the 1st year after establishment. This is believed to be caused by summer drought and interference from herbaceous competitors (see Plant Response To Fire) [33,96,102]. Schultz and others  reported the emergence of wedgeleaf ceanothus seedlings in the central California Sierra Nevada foothills occurred in mid-March and April. By mid-June, root depths may reach 30 to 40 inches (76-102 cm) while above ground stems and branches may reach 6 to 8 inches (15-20 cm) tall. Wedgeleaf ceanothus roots penetrate much further than those of herbaceous competitors. It is believed that wedgeleaf ceanothus' vigorous root growth beyond the maximum penetration of grass roots in the 1st year of growth is critical to obtaining enough moisture to establish . Wedgeleaf ceanothus in the absence of fire may become established in shrub openings . In their review of chaparral vegetation, Keeley and Keeley  point out that obligate-seeding shrubs, including wedgeleaf ceanothus, have more opportunities for genetic recombination than obligate-sprouting species. Recruitment of wedgeleaf ceanothus between fire intervals is very uncommon and rarely results in successful establishment under the canopy of mature shrubs, even in stands unburned for more than a century [60,61].
The ability of wedgeleaf ceanothus to regenerate vegetatively is unclear. One observation
from Biswell and Gilman  noted asexual regeneration of wedgeleaf ceanothus
through layering after a prolonged
period without fire and grazing.
Wedgeleaf ceanothus covers a wide array of geographic and topographic locations from valley floors to hillsides and foothill slopes. It generally occurs in elevations < 6000 feet (1800 m) in California and Oregon on dry mountain slopes and ridges within the Upper Sonoran Life Zone .
Climate of this region is considered "Mediterranean" with a majority of annual precipitation occurring in winter with long summer droughts. Typically wedgeleaf ceanothus occurs in areas where annual precipitation ranges from approximately 10 to 35 inches (250-900 mm) and where 80% of the annual total precipitation occurs in the fall, winter, and spring . Annual average precipitation ranges from north to south:
|State||Location||Mean Annual Precipitation||Citation|
|Oregon||Medford||16.5 inches (419 mm)|||
|California||Santa Rosa||35 inches (888.5 mm)|||
|California||Fresno||29.9 inches (760 mm)|||
|California||San Mateo County||25.7 inches (654 mm)|||
|California||Los Angeles||15.7 inches (400 mm)|
|California||San Diego||10 inches (250 mm)|||
Wedgeleaf ceanothus occurs in chaparral vegetation types in California and Oregon and
is commonly associated with poor, rocky soils [41,61]. Wedgeleaf ceanothus is more
frequently found growing on nonserpentine soils of sandstone origins than on
serpentine soils . However, wedgeleaf ceanothus can be found on both types of soils and is
considered an indicator species for field identification of serpentine soil conditions
in California and Oregon .
Wedgeleaf ceanothus stand development is not easily predicted and is dependent on a number of variables including plant association, habitat type, proximity to boundaries with other habitat types, geographic and topographic location, climate, fire intensity, and time since last fire . This is in contrast to early theories that outline succession in chaparral as an orderly progression of seral stages that reach a climax as originally defined by Clements .
Wedgeleaf ceanothus stands change rapidly during the first 1 to 4 years postfire. In areas where wedgeleaf ceanothus associates with sprouting shrub species postfire succession can typically be described in 3 stages: (1) During the 1st postfire year native and nonnative vegetation forms the dominant cover, while chaparral shrub seedlings and sprouts emerge. (2) During the 2nd postfire year, high mortality of shrub and subshrub seedlings takes place with decreased native and increased nonnative herbaceous plants. (3) In subsequent years, the remaining shrub seedlings and sprouts become well established while herbaceous vegetation gradually decreases. After 8 to 10 years, a relatively mature chaparral cover with little understory exists [52,102]. Very little is known about the average life span of wedgeleaf ceanothus, although many agree with Biswell's  observations that substantial mortality begins in stands >50 years old.
Stand development seems to be largely driven by water availability. While sometimes found in pure stands, wedgeleaf ceanothus often codominates or associates with other shrub species during stand development. The subsequent dominance of any one species is greatly influenced by water availability and can be a major contributor to the occurrence and frequency of wedgeleaf ceanothus in the resulting stand structure .
In most stands wedgeleaf ceanothus can form impenetrable thickets that may retard understory development of other plant species . However, in long disturbance-free periods, wedgeleaf ceanothus stands can undergo decline because of interference from introduced sprouting shrubs or overstory species from nearby stands . For example, suppression of fire in chaparral is thought to favor crown-sprouting species over obligate seeders. Research conducted in the southern coastal ranges of California found that fire suppression is primarily responsible for the conversion of large acreages of shrub lands where wedgeleaf ceanothus occurred to oak woodlands . Wedgeleaf ceanothus has shown significant decreases in areas susceptible to shading from overstory species, in particular by Nuttall's scrub oak and toyon on coastal ranges [63,106]. Generally wedgeleaf ceanothus declines in undisturbed stands that reach > 100 years old [53,60]. In unburned areas of the south coastal ranges of California , stands of wedgeleaf ceanothus that have not burned for over a century are replaced by longer lived species such as chamise .
Wedgeleaf ceanothus is an actinorrhizal plant that has the ability to fix
atmospheric nitrogen [24,28,29]. This gives wedgeleaf ceanothus a competitive
advantage over other non-nitrogen fixing shrubs herbs and grasses, especially on
nitrogen-deficient soils . Over a given year wedgeleaf ceanothus nodulates
nitrogen at an estimated rate of 54 pounds per acre .
Wedgeleaf ceanothus occurs in the Mediterranean-climate zone where annual summer drought is typical. The unpredictability of both intensity and duration of this drought has a major influence on the development strategies of wedgeleaf ceanothus. All plant growth must occur before water stress triggers dormancy. A 2-year study in the foothills of Sequoia National Park, California, found that wedgeleaf ceanothus begins phenological development in late winter and early spring and exhibits simultaneous branch elongation, leaf initiation, and flowering. This adaptation insures completion of all phenological stages before the onset of drought . Wedgeleaf ceanothus is able to survive extreme drought conditions as observed during the 1975-1977 drought in California .
Wedgeleaf ceanothus flowers from February to April depending on location . Leaf life span averaged 14.4 months in the eastern foothills of the Santa Cruz Mountains . Wedgeleaf ceanothus thrives in the cool, wet winter and withers during the dry summer. Wedgeleaf ceanothus is considered a sclerophyll which is characterized by small leaves, short internodes, thick cuticle, sunken stomates, high proportion of lignified cells, and leaves with a waxy coating. All of these traits help wedgeleaf ceanothus to survive water loss through transpiration .
Burning by Native Americans: Before European settlement, burning by Native Americans impacted fire intervals and vegetation structure, especially in areas where wedgeleaf ceanothus occurs . This is especially apparent in chaparral stands or oak woodlands where wedgeleaf ceanothus and other chaparral shrub species are common in the understory. In California, observations in oak woodlands in the mid-twentieth century found increasing densities of chaparral species, including wedgeleaf ceanothus, in the understory of oaks. This is believed to be due to suppression of native American burning practices and wildfire . Burning by aboriginals in California was thought to be primarily for maintenance of hunting grounds and prevention of large "devastating" fires in mature stands of wedgeleaf ceanothus, a species recognized by natives to be very important to wildlife. Native Americans probably ignited low-intensity grassfires during the spring in oak woodlands and winter range of regional ungulate species, to prevent wedgeleaf ceanothus from being consumed by intense, naturally-ignited fires that typically occurred during mid-summer [17,73]. The extent and rationale of burning in chaparral by natives is in need of further study, especially in the context of ecological restoration.
Fire regimes: Opinions among chaparral scientists conflict on the degree to which chaparral is dependent on fire . Historical fire intervals of 30 to 100 years appear most favorable for wedgeleaf ceanothus stand maintenance [77,82]. Theoretically, longer fire intervals favor wedgeleaf ceanothus by allowing larger quantities of annually-deposited, long-lived seed to accumulate. This provides better chances for postfire establishment . This is counter to many land management fire prescriptions, especially in wildland-urban interface areas, where hazardous fuel reduction is a priority. Human caused ignitions, intentional and unintentional, cause fire intervals of 20-30 years, especially in stands in close proximity to towns or cities . These intervals may be too short for sufficient seed accumulation.
The following table provides fire regime intervals for communities and ecosystems in which wedgeleaf ceanothus commonly occurs. For more information on fire regimes in these communities, see the FEIS review for the dominant species listed here. Find further fire regime information for the plant communities in which this species may occur by entering the species name in the FEIS home page under "Find Fire Regimes".
|Community or Ecosystem||Dominant Species||Fire Return Interval Range (years)|
|California chaparral||Adenostoma and/or Arctostaphylos spp.||< 35 to < 100|
|coastal sagebrush||Artemisia californica||< 35 to < 100|
|California montane chaparral||Ceanothus and/or Arctostaphylos spp.||50-100 |
|California steppe||Festuca-Danthonia spp.||< 35 [82,100]|
|western juniper||Juniperus occidentalis||20-70 |
|Jeffrey pine||Pinus jeffreyi||5-30|
|Pacific ponderosa pine*||Pinus ponderosa var. ponderosa||1-47|
|California oakwoods||Quercus spp.||< 35 |
|coast live oak||Quercus agrifolia||2-75 |
|coastal Douglas-fir*||Pseudotsuga menziesii var. menziesii||40-240 [6,54,91]|
|California mixed evergreen||Pseudotsuga menziesii var. menziesii-Lithocarpus densiflorus-Arbutus menziesii||<35|
|canyon live oak||Quercus chrysolepis||<35 to 200|
|blue oak-foothills pine||Quercus douglasii-P. sabiniana||<35|
|Oregon white oak||Quercus garryana||< 35 |
|California black oak||Quercus kelloggii||5-30 |
|interior live oak||Quercus wislizenii||< 35 |
Since wedgeleaf ceanothus establishment is synchronous after burning, wedgeleaf ceanothus typically forms even-aged stands . Wedgeleaf ceanothus stands can become very dense at maturity . Frequently during early stages of wedgeleaf ceanothus stand development, stands are densely crowded and allow few, if any, herbaceous species to occur under the canopy . As stands mature, self-thinning occurs; then stand structure, density, and composition stabilize. Stand thinning seems to result from intraspecific competition for moisture and is highly correlated with how close shrubs grow to one another. Clumped distributions tend to show the greatest rates of mortality during times of high moisture stress. This pattern of mortality is present in both juvenile and mature stands of wedgeleaf ceanothus and other ceanothus species .
Postfire establishment patterns at small scales: Wedgeleaf ceanothus stands can become very dense during maturity allowing few, if any, herbaceous species to occur under its canopy . In these areas postfire emergence and survival of seedlings is high due to a lack of interference from grasses and other herbaceous species . Florence and Florence's  observations from prescribed fire activities noted that postfire wedgeleaf ceanothus seedlings were frequently found near burned skeletons of wedgeleaf ceanothus or other sprouting shrubs. They assumed that the dead remains of the shrubs provided a better habitat for the wedgeleaf ceanothus seedlings by protecting the seedlings from browsing. Also the authors hypothesized that high temperatures or charate released during burning may have enhanced germination of wedgeleaf ceanothus by increasing mortality of other competing herbaceous and shrub species .
Fire and nodulation of wedgeleaf ceanothus:
In California an irrigation experiment during mid-summer investigated whether water
stress inhibits nodulation of postfire wedgeleaf ceanothus seedlings. The authors
found a significant (P< 0.05) increase in nodulation frequency in well-hydrated
sites, compared to adjacent xeric sites, which are typical of wedgeleaf ceanothus
habitat. Also noted in this study was an interesting delay in nodulation in 1st
year postfire seedlings. Nodulation of postfire seedlings did not occur at the
onset of spring immediately after germination when soil moisture values where high.
Pratt and others  suggested that wedgeleaf ceanothus might be able to suppress
nodulation by delaying nitrogen fixation until adequate carbohydrate reserves and
water availability are synchronously established.
FIRE MANAGEMENT CONSIDERATIONS:
Wildfire suppression: policies during the 20th century have interrupted the natural fire cycle of many types of chaparral including those where wedgeleaf ceanothus occurs. Current management of chaparral stands includes the use of prescribed fire to maintain natural fire regimes. However, large areas of continuous "decadent" wedgeleaf ceanothus chaparral exist where fire has not occurred for over a century. Fires in these areas burn with high intensity over large areas, potentially beyond historical levels of severity . Consequently, fire suppression's overall effects are thought to reduce the numbers of wildfires, but increase overall area burned [76,107]. Note that wedgeleaf ceanothus stems identified as "decadent" may not necessarily be dead; see .
Frequency of burning: Research conducted during the mid-20th century focused on using frequent fires to reduce wedgeleaf ceanothus and chamise stands for browse habitat improvements (see Importance To Livestock And Wildlife). Stands of wedgeleaf ceanothus can be decimated when fires are frequent enough to kill postfire seedlings that have not matured enough to produce a seed crop . One experimental burn conducted 3 years after burning on a young stand of wedgeleaf ceanothus resulted in 100% mortality of all stems and 0% postfire establishment of new wedgeleaf ceanothus seedlings the following spring . This phenomenon has been called "shock stagnation," a semipermanent degradation of the native vegetation in which exotic grasses and/or forbs dominate. This tactic was frequently used during the mid-1900s .
The duration of time that wedgeleaf ceanothus can exist without fire is unknown.
Seasonality of Burning: Wedgeleaf ceanothus seedlings must develop considerable root systems during the spring before the cessation of seasonal rains. Middle- to late-spring burns may result in very high wedgeleaf ceanothus seedling mortality [20,39].
Wedgeleaf ceanothus exhibited successful rates of establishment when burning was conducted before winter . The authors believe burning before the cool season allows seedlings of wedgeleaf ceanothus to establish before annual herbaceous species arrive, giving wedgeleaf ceanothus a competitive moisture advantage and subsequent higher rates of survival through the following dry season . However, low fire intensities commonly associated with prescribed fires during the cool season are also directly correlated with high coverages of herbaceous species during the 1st year postfire . Most prescribed fires occur during the cool season due to safety issues. It may be difficult to use prescribed fire for ecological restoration while addressing safety needs. Further research is needed on the effects of seasonality of burning and establishment wedgeleaf ceanothus.
Postfire establishment and interference: One concern following fire is possible interference from herbaceous species. Postfire mortality of wedgeleaf ceanothus seedlings suggests competition of water and nutrient resources from nearby herbaceous plants is an important factor influencing initial survival rates . This effect may be less common in areas with low rainfall. Schultz and others  in the Sierra Nevada of central California found the abundance and vigor of wedgeleaf ceanothus seedlings were negatively associated with increasing densities of herbaceous species, especially grasses. Postfire establishment of grasses in this area usually precedes wedgeleaf ceanothus, quickly creating a mass of roots difficult for shrub species to push young roots through. The authors believed competition between grasses and wedgeleaf ceanothus seedlings for moisture during establishment is responsible for dramatic reductions in numbers of wedgeleaf ceanothus seedlings 1 year postfire. In their study, 3 months after emergence, wedgeleaf ceanothus growing without interference from other species developed roots to a depth of 43 inches (109 cm) and had 26 inches (66 cm) of lateral growth. In contrast, under the same watering regime, wedgeleaf ceanothus seedlings growing along with Italian ryegrass (Lolium multiflorum) had a maximum root depth of 11.5 inches (29 cm) with very little lateral growth . Wedgeleaf ceanothus seedling mortality was highest when density of Italian ryegrass was >39% at maturity. Biswell  found that native herbaceous density > 65% severely affected survival of wedgeleaf ceanothus and other chaparral shrubs. Contrary to Schultz and others , Beyers and others  found no significant (P>0.05) differences in wedgeleaf ceanothus stem densities in plots in southern California that either had or had not been reseeded with Italian ryegrass 5 years postfire. However in this study grass densities were low and rainfall less than average .
Postfire competition for light often controls shrub species dominance in chaparral. In ecotonal regions between coastal sage and chaparral, stands 30 years postfire showed declining density of purple sage in mixed stands with wedgeleaf ceanothus. This was not caused by allelopathy but by competition for light. During stand maturity wedgeleaf ceanothus grows taller and shades purple sage . Similar results have been found from comparable research using different Ceanothus species. .
Fire intensity and postfire establishment: Wedgeleaf ceanothus establishment is associated with areas where the prefire canopy was dense and consequently high fire severity occurred. Soil heating is the primary trigger to end dormancy for wedgeleaf ceanothus (see Seedling establishment/growth). A study hypothesized that in the absence of fire, abnormally large accumulations of fuel over a period of time would result in extreme fire severities, reducing numbers of buried viable seed . However, the seed of wedgeleaf ceanothus was found to be very resistant to heat and high fire severity . Prescribed fires in chaparral types are conducted during the fall after the onset of the rainy season and generally exhibit lower fire intensity than typical wildfires during late summer or early fall . Effects of low intensity burns on germination rates of wedgeleaf ceanothus are not well known.
Most fire ecology studies conducted in chaparral vegetation have focused attention on the fire ecology of stands that exist on sandstone-derived soils, leaving the fire ecology of stands on serpentine soils largely uninvestigated. Wedgeleaf ceanothus is found in serpentine soils, though it is more common and more abundant on nonserpentine soils . This could be due to lower fire severities. Serpentine soils generally support lower densities of chaparral species, have lower concentrations of fuel, and burn with lower severity than fires on nonserpentine soils. These fires may not break seed dormancy in wedgeleaf ceanothus . For more information on serpentine flora ecology see .
Pre-and postfire grazing: Timing and intensity of cattle grazing can affect wedgeleaf ceanothus. Heavy browsing of wedgeleaf ceanothus lowers seed production and reduces the potential for future establishment of wedgeleaf ceanothus after burning. In areas where heavy grazing occurs, young wedgeleaf ceanothus seedlings may not produce sufficient seed before being grazed to regenerate after fire . The combined effects of burning and heavy grazing on wedgeleaf ceanothus have been used to convert stands of wedgeleaf ceanothus to pasture . Biswell and Gilman  recommended burning in areas susceptible to heavy grazing at intervals >20 years to allow for sufficient stand development and seed production.
Wedgeleaf ceanothus is especially sensitive to browsing by deer after fire. Light to heavy browsing on young wedgeleaf ceanothus seedlings has reduced abundance of seedlings following burning . In California, after an unknown amount of time after burning, "light" browsing by deer resulted in stunted seedlings averaging heights of 18 inches (46 cm). Seedlings protected from browsing by enclosures grew rapidly and averaged >27 inches (69 cm) in height. Mortality rates of stems from browsing were dramatically reduced after shrubs reached 5 years of age .
After fire, deer and other ungulates prefer grazing in postfire stands of wedgeleaf ceanothus. Peak browsing in these areas occurs for up to 3 years after burning [66,67].
Effects of cattle grazing in stands of wedgeleaf ceanothus along with manipulation of chaparral for "range improvement" and "improvement of wildlife habitat" are well documented. For more information please refer to [22,44,45,46,47,49,93,95,103].
Palatability/nutritional value: The foliage, twigs, and seedlings of wedgeleaf ceanothus are highly palatable to mule deer, black-tailed deer, and domestic sheep and goats [20,47,97]. Overall palatability to cattle is low . Seeds are highly palatable to many small mammals, birds, and insects .
Wedgeleaf ceanothus offers year around high-protein browse for black-tailed deer, mule deer and other wildlife species . Domestic sheep prefer wedgeleaf ceanothus for browse, while cattle will eat wedgeleaf ceanothus when other forage is scarce . The following table shows monthly fluctuations in crude protein content of wedgeleaf ceanothus . Values equal percentages of crude protein from oven-dried plant material. Crude protein peaks in spring and summer.
Wedgeleaf ceanothus provides high levels of nutrients important to ungulate species. Mineral concentrations of wedgeleaf ceanothus for healthy deer populations are reported by Scrivner and others . The following table shows mean percent mineral composition of oven-dry wedgeleaf ceanothus material sampled from June, 1985, to July, 1986, in California.
Gordon and Sampson  also provide nutritional information on wedgeleaf ceanothus.
Wedgeleaf ceanothus provides cover for many wildlife species including California quail,
black-tailed jackrabbit, brush rabbit, and mourning dove [20,26]. The preferred habitat
of the chaparral mouse is under the protective branches of wedgeleaf ceanothus . Many
other small rodents including the deer mouse, California mouse, house mouse, and California
pocket mouse, hide, feed, and nest beneath the canopy of wedgeleaf ceanothus . Plants
frequently grow tall enough, and with sufficient density, to furnish good hiding cover for
larger ungulates such as mule deer. Barrett  found that black-tailed deer preferred
wedgeleaf ceanothus chaparral over other adjacent cover types for browse in the foothill
region of Mt Lassen, California.
VALUE FOR REHABILITATION OF DISTURBED SITES:
Wedgeleaf ceanothus is well suited for use in rehabilitation because of rapid growth rates and an ability to improve soil fertility through nitrogen fixation. Some cultivars are now commercially available . Wedgeleaf ceanothus has been successfully planted onto many types of disturbed sites throughout southern California and the desert Southwest . It established well on disturbed sites near Lake Tahoe, California, but exhibited poor long-term survival due to cold winter temperatures . Properly treated seed can be hand-sown onto burned slopes as an emergency revegetation measure in southern California chaparral. Good seedling establishment has been reported following seeding of these sites . Wedgeleaf ceanothus can be used for stabilization of neutral and acid soils. However, transplanting from a nursery is recommended due to the difficulty and expense of harvesting seeds .
The Miwok Indians of the Sierra Nevada region of California used the young, straight shoots of wedgeleaf ceanothus for basketry material. The young shoots are so valuable that the Miwok have historically manipulated stands of wedgeleaf ceanothus by pruning, burning, or coppicing to induce rapid elongation of young growth . The Kawaiisu used straightened twigs of wedgeleaf ceanothus for arrows and also used the shrub for fire wood . The Mono tribe used stems of wedgeleaf ceanothus for basketry materials .
OTHER MANAGEMENT CONSIDERATIONS:
No information is available for this topic.
1. Ackerly, David. 2004. Functional strategies of chaparral shrubs in relation to seasonal water deficit and disturbance. Ecological Monographs. 74(1): 25-44. 
2. Adams, Lowell. 1962. Planting depths for seeds of three species of Ceanothus. Res. Note PSW-194. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 3 p. 
3. Anderson, Kat. 1991. Wild plant management: Cross-cultural examples of the small farmers of Jaumave, Mexico, and the southern Miwok of the Yosemite region. Arid Lands Newsletter. 31: 18-23. 
4. Anderson, M. Kat; Moratto, Michael J. 1996. Native American land-use practices and ecological impacts. 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: 187-206. 
5. Armstrong, Wayne P. 1966. Ecological and taxonomic relationships of Cupressus in southern California. Los Angles, CA: California State University. 129 p. Thesis. 
6. 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. 
7. Baker, G. A.; Rundel, P. W.; Parsons, D. J. 1982. Comparative phenology and growth in three chaparral shrubs. Botanical Gazette. 143(1): 94-100. 
8. Baker, Gail A.; Rundel, Philip W.; Parsons, David J. 1981. Ecological relationships of Quercus douglasii (Fagaceae) in the foothill zone of Sequoia National Park, California. Madrono. 28(1): 1-12. 
9. Barbour, Michael G.; Johnson, Ann F. 1977. Beach and dune. In: Barbour, M. G.; Major, J., eds. Terrestrial vegetation of California. New York: John Wiley and Sons: 223-261. 
10. Barrett, Reginald H. 1982. Habitat preferences of feral hogs, deer, and cattle on a Sierra foothill range. Journal of Range Management. 35(3): 342-346. 
11. Barrett, Reginald H. 1983. Food habits of coyotes, Canis latrans, in eastern Tehama County, California. California Fish and Game. 69(3): 184-186. 
12. Barro, Susan C.; Conard, Susan G. 1987. Use of ryegrass seeding as an emergency revegetation measure in chaparral ecosystems. Gen. Tech. Rep. PSW-102. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 12 p. 
13. Belcher, Earl. 1985. Handbook on seeds of browse -- shrubs and forbs. Technical Publication R8-TP8. Atlanta, GA: U.S. Department of Agriculture, Forest Service, Southern Region. 246 p. In cooperation with: Association of Official Seed Analysts. 
14. 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. 
15. Beyers, Jan L.; Wakeman, Carla D.; Conard, Susan G.; Wohlemuth, Peter M. 2002. Impacts of postfire grass seeding on vegetation recovery in southern California chaparral. In: Sugihara, Neil G.; Morales, Maria; Morales, Tony, eds. Fire in California ecosystems: integrating ecology, prevention and management: Proceedings of the symposium; 1997 November 17-20; San Diego, CA. Misc. Pub. No. 1. [Place of publication unknown]: Association for Fire Ecology: 318-324. 
16. 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. 
17. Biswell, H. H. 1956. Ecology of California grasslands. Journal of Forestry. 9: 19-24. 
18. Biswell, H. H. 1958. The use of fire in California chaparral for game habitat improvement. In: Proceedings: Society of American Foresters meeting; 1957 November 10-13; Syracuse, NY. Washington, DC: Society of American Foresters: 151-155. 
19. Biswell, H. H. 1959. Prescribed burning and other methods of deer range improvement in ponderosa pine in California. In: Proceedings, Society of American Foresters; 1959; San Francisco, CA. Bethesda, MD: Society of American Foresters: 102-105. 
20. Biswell, H. H. 1961. Manipulation of chamise brush for deer range improvement. California Fish and Game. 47(2): 125-144. 
21. Biswell, H. H. 1963. Research in wildland fire ecology in California. In: Proceedings, 2nd annual Tall Timbers fire ecology conference; 1963 March 14-15; Tallahassee, FL. No. 2. Tallahassee, FL: Tall Timbers Research Station: 63-97. 
22. Biswell, H. H.; Gilman, J. H. 1961. Brush management in relation to fire and other environmental factors on the Tehama deer winter range. California Fish and Game. 47(4): 357-389. 
23. 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. 
24. Bormann, Bernard T. 1988. A masterful scheme: Symbiotic nitrogen-fixing plants of the Pacific Northwest. University of Washington Arboretum Bulletin. 51(2): 10-14. 
25. Bowcutt, Frederica S. 1999. A floristic study of Sugarloaf Ridge State Park, Sonoma County, California. Aliso. 18(1): 19-34. 
26. 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. 
27. Corke, Robert Lyall. 1975. A biosystematic study of interpopulational variation in Ceanothus cuneatus (Rhamnaceae). Sacramento, CA: California State University. 39 p. Thesis. 
28. DeBano, L. F.; Conrad, C. E. 1978. The effect of fire on nutrients in a chaparral ecosystem. Ecology. 59(3): 489-497. 
29. Delwiche, C. C.; Zinke, Paul J.; Johnson, Clarence M. 1965. Nitrogen fixation by ceanothus. Plant Pathology. 40: 1045-1047. 
30. Detling, LeRoy E. 1961. The chaparral formation of southwestern Oregon, with considerations of its postglacial history. Ecology. 42(2): 348-357. 
31. Dodd, Richard S. 1992. Noteworthy collections: California. Madrono. 39(1): 79. 
32. Dunn, Anthony T. 1987. Population dynamics of the Tecate cypress. In: Conservation and management of rare and endangered plants: Proceedings of a conference on the conservation and management of rare and endangered plants; [Date unknown]; [Location unknown]. [Place of publication unknown]: [Publisher unknown]: 367-376. On file with: U.S. Department of Agriculture, Forest Service, Intermountain Research Station, Fire Sciences Laboratory, Missoula, MT. 
33. Dunne, Jim; Dennis, Ann; Bartolome, J. W.; Barrett, R. H. 1991. Chaparral response to a prescribed fire in the Mount Hamilton Range, Santa Clara County, California. Madrono. 38(1): 21-29. 
34. Epling, Carl; Lewis, Harlan. 1942. The centers of distribution of the chaparral and coastal sage associations. The American Midland Naturalist. 27: 445-462. 
35. Evans, Raymond A.; Biswell, Harold H.; Palmquist, Debra E. 1987. Seed dispersal in Ceanothus cuneatus and C. leucodermis in a Sierran oak-woodland savanna. Madrono. 34(4): 283-293. 
36. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. 
37. Fessenden, R. J. 1979. Use of actinorrhizal plants for land reclamation and amenity planting in the U.S.A. and Canada. In: Gordon, J. C.; Wheeler, C. T.; Perry, D. A., eds. Symbiotic nitrogen fixation in the management of temperate forests: Proceedings of a workshop; 1979 April 2-5; Corvallis, OR. Corvallis, OR: Oregon State University, Forest Research Laboratory: 403-419. 
38. Florence, Melanie. 1986. Plant succession on prescribed burn sites at Pinnacles National Monument. Fremontia. 14(3): 31-33. 
39. Florence, Scott F.; Florence, Melanie A. 1988. Prescribed burning effects in central California chaparral. Rangelands. 10(3): 138-140. 
40. 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. 
41. Gardner, Robert A. 1958. Soil-vegetation associations in the redwood - Douglas-fir zone of California. In: Proceedings, 1st North American forest soils conference; [Date of conference unknown]; East Lansing, MI. East Lansing, MI: Michigan State University, Agricultural Experiment Station: 86-101. 
42. 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. 
43. Gause, Gerald W. 1966. Silvical characteristics of bigcone Douglas-fir (Pseudotsuga macrocarpa). PSW-39. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 10 p. 
44. Gaylord, Vernon J.; Westfall, Stanley E. 1971. Wedgeleaf ceanothus canopy does not affect total herbage yield. Res. Note PSW-253. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 4 p. 
45. Gibbens, R. P.; Pieper, R. D. 1962. The response of browse plants to fertilization. California Fish and Game. 48(4): 268-281. 
46. Gibbens, R. P.; Schultz, A. M. 1962. Manipulation of shrub form and browse production in game range improvement. California Fish and Game. 48: 49-64. 
47. Gibbens, R. P.; Schultz, A. M. 1963. Brush manipulation on a deer winter range. California Fish and Game. 49(2): 95-118. 
48. 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. 
49. 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. 
50. Greenlee, Jason M.; Langenheim, Jean H. 1990. Historic fire regimes and their relation to vegetation patterns in the Monterey Bay area of California. The American Midland Naturalist. 124(2): 239-253. 
51. Hanes, Ted L. 1971. Succession after fire in the chaparral of southern California. Ecological Monographs. 41(1): 27-52. 
52. 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. 
53. Hedrick, Donald W. 1951. Studies on the succession and manipulation of chamise brushlands in California. College Station, TX: Texas Agricultural and Mechanical College. 113 p. Dissertation. 
54. Henderson, C. J. 1988. Managing aspen in the mixedwood forest. In: Samoil, J. K., ed. Management and utilization of northern mixedwoods: Proceedings of a symposium; 1988 April 11-14; Edmonton, AB. Inf. Rep. NOR-X-296. Edmonton, AB: Canadian Forestry Service, Northern Forestry Centre: 50-52. 
55. Hickman, James C., ed. 1993. The Jepson manual: Higher plants of California. Berkeley, CA: University of California Press. 1400 p. 
56. Hitchcock, C. Leo; Cronquist, Arthur. 1961. Vascular plants of the Pacific Northwest. Part 3: Saxifragaceae to Ericaceae. Seattle, WA: University of Washington Press. 614 p. 
57. Holmes, Tyson H. 1990. Botanical trends in northern California oak woodland. Rangelands. 12(1): 3-7. 
58. 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]. 
59. Keeley, Jon E. 1975. Longevity of nonsprouting Ceanothus. The American Midland Naturalist. 93(2): 504-507. 
60. Keeley, Jon E. 1982. Distribution of lightning- and man-caused wildfires in California. 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: 431-437. 
61. Keeley, Jon E. 1987. Role of fire in seed germination of woody taxa in California chaparral. Ecology. 68(2): 434-443. 
62. Keeley, Jon E. 1991. Seed germination and life history syndromes in the California chaparral. The Botanical Review. 57(2): 81-116. 
63. Keeley, Jon E. 1992. Demographic structure of California chaparral in the long-term absence of fire. Vegetation Science. 3(1): 79-90. 
64. Keeley, Jon E. 1992. Recruitment of seedlings and vegetative sprouts in unburned chaparral. Ecology. 73(4): 1194-1208. 
65. 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. 
66. Kie, John G. 1984. Deer habitat use after prescribed burning in northern California. PSW-369. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 3 p. 
67. Klinger, Robert C.; Kutilek, Michael J.; Shellhammer, Howard S. 1989. Population responses of black-tailed deer to prescribed burning. Journal of Wildlife Management. 53(4): 863-871. 
68. Kruckeberg, Arthur R. 1984. California serpentines: flora, vegetation, geology, soils and management problems. Publications in Botany Volume 48. Berkeley, CA: University of California Press. 180 p. 
69. 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. 
70. Kummerow, Jochen; Ellis, Barbara A.; Mills, James N. 1985. Post-fire seedling establishment of Adenostoma fasciculatum and Ceanothus greggii in southern California chaparral. Madrono. 32(3): 148-157. 
71. Larson, Frederic R.; Wolters, Gale L. 1983. Overstory-understory relationships: mixed conifer 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: 21-25. 
72. Lawrence, George E. 1966. Ecology of vertebrate animals in relation to chaparral fire in the Sierra Nevada foothills. Ecology. 47(2): 278-291. 
73. Lewis, Henry T., author; Bean, Lowell John, ed. 1973. Patterns of Indian burning in California: Ecology and ethnohistory. Ballena Press Anthropological Papers No. 1. Ramona, CA: Ballena Press. 101 p. 
74. Marion, Lois H. 1943. The distribution of Adenostoma sparsifolium. The American Midland Naturalist. 29(1): 206-116. 
75. McPherson, James K.; Muller, Cornelius H. 1967. Light competition between Ceanothus and Salvia shrubs. Bulletin of the Torrey Botanical Club. 94(1): 41-55. 
76. Minnich, Richard A. 1983. Fire mosaics in southern California and northern Baja California. Science. 219: 1287-1294. 
77. 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. 
78. Munz, Philip A. 1973. A California flora and supplement. Berkeley, CA: University of California Press. 1905 p. 
79. Odion, Dennis C. 2000. Seed banks of long-unburned stands of maritime chaparral: composition, germination behavior, and survival with fire. Madrono. 47(3): 195-203. 
80. Odion, Dennis C.; Davis, Frank W. 2000. Fire, soil heating, and formation of vegetation patterns in chaparral. Ecological Monographs. 70(1): 149-169. 
81. Parsons, David J.; Rundel, Philip W.; Hedlund, Richard P.; Baker, Gail A. 1981. Survival of severe drought by a non-sprouting chaparral shrub. American Journal of Botany. 68(7): 973-979. 
82. Paysen, Timothy E.; Ansley, R. James; Brown, James K.; [and others]. 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. 
83. Plummer, A. Perry. 1977. Revegetation of disturbed Intermountain area sites. In: Thames, J. C., ed. Reclamation and use of disturbed lands of the Southwest. Tucson, AZ: University of Arizona Press: 302-337. 
84. Powers, Robert F. 1990. Pinus sabiniana Dougl. digger 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: 463-469. 
85. Pratt, S. D.; Konopka, A.S.; Murray, M. A.; [and others]. 1997. Influence of soil moisture on the nodulation of post fire seedlings of Ceanothus spp. growing in the Santa Monica Mountains of southern California. Physiologia Plantarum. 99(4): 673-679. 
86. Pugnaire, Francisco I.; Chapin, F. Stuart, III. 1993. Controls over nutrient resorption from leaves of evergreen Mediterranean species. Ecology. 74(1): 124-129. 
87. Quick, Clarence R. 1935. Notes on the germination of ceanothus seeds. Madrono. 3: 135-140. 
88. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. 
89. Reed, Lois J.; Sugihara, Neil G. 1987. Northern oak woodlands--ecosystem in jeopardy or is it already too late? 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: 59-63. 
90. Reed, Merton J. 1974. Ceanothus L. ceanothus. 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: 284-290. 
91. Ripple, William J. 1994. Historic spatial patterns of old forests in western Oregon. Journal of Forestry. 92(11): 45-49. 
92. Safford, Hugh D.; Harrison, Susan. 2004. Fire effects on plant diversity in serpentine vs. sandstone chaparral. Ecology. 85(2): 539-548. 
93. Sampson, Arthur W.; Burcham, L. T. 1954. Costs and returns of controlled brush burning for range improvement in northern California. Range Improvement Studies No. 1. Sacramento, CA: California Department of Natural Resources, Division of Forestry. 41 p. 
94. Schlesinger, William H.; Gill, David S. 1980. Biomass, production, and changes in the availability of light, water, and nutrients during the development of pure stands of the chaparral shrub, Ceanothus megacarpus, after fire. Ecology. 61(4): 781-789. 
95. Schultz, A. M.; Biswell, H. H. 1952. Competition between grasses reseeded on burned brushlands in California. Journal of Range Management. 5: 338-345. 
96. Schultz, A. M.; Launchbaugh, J. L.; Biswell, H. H. 1955. Relationship between grass density and brush seedling survival. Ecology. 36(2): 226-238. 
97. 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. 
98. Shiflet, Thomas N., ed. 1994. Rangeland cover types of the United States. Denver, CO: Society for Range Management. 152 p. 
99. 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. 
100. Stomberg, Mark R.; Kephart, Paul; Yadon, Vern. 2001. Composition, invasibility, and diversity in coastal California grasslands. Madrono. 48(4): 236-252. 
101. Stone, Chester O. 1965. Modoc cypress, Cupressus bakeri Jeps., does occur in Modoc County. Aliso. 6(1): 77-87. 
102. Sweeney, James R. 1956. Responses of vegetation to fire: A study of the herbaceous vegetation following chaparral fires. University of California Publications in Botany. 28(4): 143-250. 
103. Talbot, M. W.; Biswell, H. H. 1942. The forage crop and its management. In: The San Joaquin Experimental Range. Bull. 663. Berkeley, CA: California Agricultural Experiment Station: 13-49. 
104. U.S. Department of Agriculture, Forest Service. 1937. Range plant handbook. Washington, DC. 532 p. 
105. U.S. Department of Agriculture, National Resource Conservation Service. 2005. PLANTS database (2004), [Online]. Available: http://plants.usda.gov/. 
106. Van Dyke, Eric; Holl, Karen D.; Griffin, James R. 2001. Maritime chaparral community transition in the absence of fire. Madrono. 48(4): 221-229. 
107. Vankat, John L.; Major, Jack. 1978. Vegetation changes in Sequoia National Park, California. Journal of Biogeography. 5: 377-402. 
108. White, C. David. 1967. Absence of nodule formation on Ceanothus cuneatus in serpentine soils. Nature. 215: 875. 
109. Wiggins, Ira L. 1980. Flora of Baja California. Stanford, CA: Stanford University Press. 1025 p. 
110. Zigmond, Maurice L. 1981. Kawaisu ethnobotany. Salt Lake City, UT: University of Utah Press. 102 p.