Bigberry Manzanita

bigberry manzanita
great-berried manzanita

More info for the terms: lignotuber, sclerophyllous, shrub

Bigberry manzanita is a native, evergreen, sclerophyllous shrub 3.3 to
19.8 feet (1-6 m) in height [39]. In coastal regions plants are
upright, sometimes arborescent, with a rounded to irregular crown. Both
varieties display this growth form. On desert borders plants are low,
compact, and spreading; this is the habit of A. glauca forma eremicola
[39,52]. Bigberry manzanita is distinguished from other manzanitas by
its large, viscid fruits containing three to six nutlets fused to form a
single large stone [26,52]. Unlike some manzanitas, this species does
not have a lignotuber [23]. It is shallow-rooted [36]. The root habit
is radially spreading, with coarse lateral roots exceeding the length of
vertical roots [33]. Bigberry manzanita can live more than 100 years
[30].

Bigberry manzanita is distributed from Mount Diablo in Contra Costa
County, California south through the South Coast, Transverse, and
Peninsular ranges and interior regions of the Sierra Juarez and Sierra
San Pedro Martir to central Baja California [6,37,52].

More info for the terms: competition, fire frequency, fire regime, frequency, natural, seed, shrubs

Adaptations: Bigberry manzanita is an obligate postfire seeder
[37,38,51]. It is best adapted to high-intensity, long-interval (100+
years) fires [19,28,29]. Long periods between fires allow plants to
reach arborescent proportions, appropriating a large amount of space and
holding it until fire [30]. The greatly increased seed production of
older shrubs helps assure that large numbers of seed will break dormancy
when fire occurs [29]. Fuels accumulated over a 100-year time span
result in a high-intensity fire, which is probably most effective in
cracking the hard seedcoat of this species [8]. High-intensity fire
also results in higher mortality rates of sprouting species, therefore
reducing competition [3].

Southern California chaparral undergoes both short and long intervals
between fire, with longer fire intervals favoring bigberry manzanita.
Frequency of lightning-ignited fire in California decreases greatly from
north to south and from high elevation to low elevation. Natural fire
frequency in low-elevation southern California chaparral is therefore
more irregular than in more northerly or higher elevation chaparral,
where lightning-ignited fires are frequent [30,32].

FIRE REGIMES :
Find 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".

More info for the terms: fire cycle, forest, prescribed fire

Bigberry manzanita populations are destroyed by repeated short-interval
fires [5]. Bigberry manzanita has been eliminated from areas of the San
Dimas Experimental Forest subjected to burning at 15-year intervals
[43]. With the present man-made fire cycle of 20 to 30 years, bigberry
manzanita is expected to regenerate, but over long periods of time
sprouting species may gain an advantage [30].

Fire in summer or fall, with the wet season still to come, favors
bigberry manzanita seedling establishment over mid- to late-spring
burning because in the latter case, summer drought occurs soon after
burning [9].

Twenty percent of bigberry manzanita fuels in mixed chaparral of Camp
Pendelton, San Diego County were dead prior to a May 15 prescribed fire.
During the fire, temperatures of 1,250 degrees Fahrenheit (676 deg C)
were recorded 31 inches (79 cm) above the soil surface. All dead and
desiccated fine bigberry manzanita fuels were consumed, and 75 percent
of green fuels were consumed [11].

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More info for the term: phanerophyte

Phanerophyte

More info for the term: association

Bigberry manzanita grows in a mediterranean-type climate, with hot, dry
summers and wet, mild winters. Santa Ana foehn winds blow over
mountains from deserts in late summer and fall [15,40]. Bigberry
manzanita grows in soils derived from granite, limestone, quartz
diorite, or serpentine and that range in texture from sandy loam with
considerable coarse fragment to loam [11,16,17,21,41,46]. Bigberry
manzanita has no statistically significant association with aspect or
degree of slope [13]. Populations in the Sierra San Pedro Martir are
restricted to sites bordering water courses [37]. Bigberry manzanita
grows at elevations below 4,500 feet (1,372 m) [39].

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

239 Pinyon - juniper
255 California coast live oak

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This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):

More info for the term: shrub

FRES28 Western hardwoods
FRES34 Chaparral - mountain shrub
FRES35 Pinyon - juniper

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

More info for the term: woodland

K023 Juniper - pinyon woodland
K033 Chaparral

More info for the terms: seed, wildfire

Fire kills bigberry manzanita [3,9,21,30]. High-intensity fire may kill
some seed, but merely cracks the seedcoat of most seeds without harming
propagules [14].


Fire-killed bigberry manzanita, 13 months after the 2002 Wolf Creek Wildfire.

Birds, rodents, and coyote eat bigberry manzanita fruits and various
seed-eating rodents consume the seeds [22,26,28].

More info for the terms: herbaceous, natural, woodland

Bigberry manzanita occurs in four communities of the chaparral
formation: manzanita (Arctostaphylos spp.), chamise (Adenostoma
fasciculatum), mixed, and desert chaparral [18,20,37,52]. It is usually
not a dominant chaparral species except in mixed chaparral of the San
Gabriel and San Bernardino mountains [37]. It occasionally forms dense,
pure stands or codominates with Eastwood manzanita in manzanita
chaparral [14].

Bigberry manzanita also occurs in singleleaf pinyon (Pinus
monophylla)-Utah juniper (Juniperus osteosperma) communities bordering
the Sonora and Mojave deserts [52].

Bigberry manzanita associates by plant community are as follows:

Chamise chaparral associates include chamise, Eastwood manzanita, white
sage (Salvia apiana), black sage (S. mellifera), California buckwheat
(Eriogonum fasciculatum), California scrub oak (Quercus dumosa),
sugarbush (Rhus ovata), and laurel sumac (Malosma laurina) [40].

Mixed chaparral associates are chamise, hoaryleaf ceanothus (Ceanothus
crassifolius), chaparral whitethorn (C. leucodermis), Eastwood manzanita,
California scrub oak, and interior live oak (Q. wislizenii) [37].

Desert chaparral associates include turbinella oak (Quercus turbinella),
Dunn oak (Q. dunnii), birchleaf mountain-mahogany (Cercocarpus
betuloides), desert ceanothus (Ceanothus greggii), redberry (Rhamnus
crocea), and hollyleaf cherry (Prunus ilicifolia) [37].

Pinyon-juniper woodland associates are singleleaf pinyon, Utah juniper,
turbinella oak, canyon live oak (Q. chrysolepis), California buckwheat,
and narrowleaf goldenbush (Haplopappus linearifolius) [52].

Herbaceous fire-followers common to the above plant communities include
golden yarrow (Convolvulus occidentalis), common deerweed (Lotus
scoparius), foxtail brome (Bromus rubens), and cheatgrass (Bromus
tectorum) [21].

Publications describing plant communities dominated or codominated by
bigberry manzanita are as follows:

Vegetation and floristics of Pinnacles National Monument [12]
Chaparral [14]
Terrestrial natural communities of California [18]
Vegetation types of the San Bernardino Mountains [20]

More info for the term: shrub

Shrub

More info for the term: litter

Bigberry manzanita leaves and litter contain toxic amounts of arbutin
and phenolic acids [50]. These compounds allelopathically inhibit
germination and growth of annuals for a distance of 3.3 to 6.6 feet (1-2
m) from the edge of the canopy drip line [38].

Bigberry manzanita is susceptible to the fungus Botrysphaeria, which
spots leaves and kills branches [44].

CA MEXICO

Bigberry manzanita is valued for native ornamental landscaping because
it is resistant to heat, drought, and cold [1,44].

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More info for the terms: fruit, scarification, seed

Flora primordia develop in late spring of the year prior to flowering.
Bigberry manzanita flowers from mid-February to mid-March in chaparral
and from mid-February to early April in pinyon-juniper woodlands.
Plants flower sporadically after these times, but later flowers do not
set fruit. Fruit ripens from late February to mid-May in chaparral and
from late February through May in pinyon-juniper woodlands. Seeds are
dispersed in late summer. Germination occurs from mid-March to
mid-April following fire scarification of seed [1,9,26,52].

More info for the terms: cover, density, forest, seed, shrubs, wildfire, woodland

Chaparral Populations: Bigberry manzanita propagules germinate during
the first postfire growing season [4]. Keeley and Zedler [30] reported
a live seedling density of 280 per acre (700/ha) at postfire year 2
following the Laguna Fire in San Diego County. Fifty-five percent of
all seedlings observed at that time were dead. Seedlings grow rapidly
when environmental conditions are favorable. Plants on the San Dimas
Experimental Forest in the San Gabriel Mountains attained heights of 3
to 6 feet (1-2 m) by postfire year 3 [49]. Bigberry manzanita on the
Barranca Canyon Burn near San Bernardino, California grew more slowly,
probably because precipitation was below normal during most of the first
postfire decade. These plants were 1 inch (2.5 cm) in height at
postfire year 1 and 15.5 inches (39.4 cm) in height at postfire year 10.
Average height at postfire year 25 was 3 feet (1 m). Many seedlings
died during a 5-year drought that began at postfire year 20 [21].

Keeley [26] reported that for plants beyond seedling size, mortality is
generally low for the first few postfire decades. Hanes [13] stated
that by postfire year 20, bigberry manzanita has attained maximum
population size. By the third and fourth postfire decades populations
decrease in numbers but increase in canopy cover by growth of remaining
shrubs.

Desert-edge Populations: Seedling establishment in chaparral desert or
pinyon-juniper woodland is typically lacking or sparse following fire.
No seedling recruitment occurred following a wildfire in chaparral
desert of Anza-Borrego State Park. Desert populations, which primarily
reproduce vegetatively, may depend upon plants in adjacent unburned
areas as important sources for postfire seed dispersal [45]. Bigberry
manzanita seedling recruitment in such communities is thusly dependent
upon animal seed dispersal followed by fire. Fires are infrequent in
such communities, occurring approximately every 100 years [37,52].

Ground residual colonizer (on-site, initial community)

More info for the terms: fruit, layering, scarification, seed

Sexual: Bigberry manzanita begins abundant sexual reproduction at
approximately age 20 [19]. Fifty-nine percent of filled seed collected
at widely separated locations was viable [31]. Fruit and seed
production increases with age. Keeley and Keeley [29] found that
90-year-old bigberry manzanita stands in San Diego County yielded over
15 times more fruits than did 23-year-old stands.

Soil-stored propagules* germinate following fire scarification of the
stone [38]. One propagule usually outcompetes the others, resulting in
establishment of one seedling per seed. Seedlings do not compete well
with annuals or sprouting species [8,30] but generally establish in
greater numbers than other obligate seeders. Its large seed apparently
gives this species a competitive advantage over other obligate seeders
[30]. Seedling mortality is high: most seedlings are outcompeted or
die from summer drought. Surviving seedlings grow rapidly, and
mortality of adult plants is extremely low until the next fire [13].

*Since several bigberry manzanita nutlets are fused into a single stone,
some ecologists refer to the stones as "seed" and the individual nutlets
as "propagules" [26]. The terms "seed" and "propagule" will be so used
in this paper.

Vegetative: Bigberry manzanita can reproduce by layering, although
plants in coastal populations rarely do so because of their upright
growth form [1,52]. Decumbent, desert-edge populations, however,
reproduce primarily by layering; sexual reproduction in these
populations is sparse [52].

Bigberry manzanita will grow epicormic sprouts following minor stem
damage [43].

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

3 Southern Pacific Border

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More info for the terms: climax, seed

Bigberry manzanita colonizes from seed in postfire plant communities and
remains a component of the community through climax [13].

The currently accepted scientific name of bigberry manzanita is
Arctostaphylos glauca Lindl. [6,39,48]. Recognized varieties and forms
are as follows:

A. glauca var. puberula J. T. Howell [39]
A. glauca var. glauca
A. glauca forma eremicola (Jeps.) Wells [48] (formerly A. glauca var.
eremicola Jeps.) [39]

Arctostaphylos glauca var. puberula is distinguished by pubescent
branchlets; branchlets of the typical variety are glabrous [39].
Arctostaphylos glauca forma eremicola is a decumbent form of bigberry
manzanita [48].

Bigberry manzanita may hybridize with pointleaf manzanita (A. pungens)
and Eastwood manzanita (A. glandulosa) [24,25].

More info for the terms: scarification, seed

Bigberry manzanita is of value for rehabilitation of disturbed
watersheds because the widespreading roots bind surface layers of soil
[17]. Plants can be established from stem cuttings or from seed. Seeds
require mechanical scarification or immersion in sulfuric acid for 6 to
15 hours to break seedcoat dormancy. Seeds should be sown in the fall,
and cuttings planted in the spring [1,44].