More info for the terms: shrub, tree
Plant Communities and Associates:
Snowbrush ceanothus is common in ponderosa pine (Pinus ponderosa) communities
[53,80,174,191,203,275,276,285,291]. Plant associates in these communities
include bitterbrush (Purshia tridentata) [19,53,114,191,203,276,291],
willow (Salix spp.), common snowberry (Symphoricarpos
albus), ninebark (Physocarpus malvaceus),
oceanspray (Holodiscus discolor), smooth sumac (Rhus glabra) [291], rose (Rosa spp.), serviceberry (Amelanchier
spp.) [174,291], quaking aspen (Populus
tremuloides) [174], giant chinquapin (Chrysolepis
chrysophylla), prince's pine (Chimaphila umbellata) [20,203], Gambel oak
(Quercus gambelii) [53], curlleaf mountain-mahogany (Cercocarpus ledifolius)
[114], manzanitas
(Arctostaphylos spp.) [19,53,191,203,276],
bittercherry (Prunus emarginata), white spirea (Spiraea
betulifolia), redstem ceanothus (Ceanothus sanguineus) [291], Ross' sedge (Carex rossii)
[19], Idaho fescue (Festuca idahoensis) [114,276], and western needlegrass [191,276]
In the intermountain ponderosa pine region, snowbrush ceanothus forms extensive
shrubfields with bush chinquapin (Chrysolepis sempervirens), greenleaf
manzanita (Arctostaphylos patula), menziesia (Menziesia ferruginea), Rocky Mountain
maple (Acer glabrum), ninebark, and willows [105].
In lodgepole pine communities (Pinus
contorta) [226,276,285], snowbrush ceanothus occurs with ponderosa pine [226,276], white fir
(Abies concolor) [276],
white spruce (Picea glauca), paper birch (Betula papyrifera), limber pine (Pinus flexilis), common juniper (Juniperus communis), quaking
aspen, bearberry (Arctostaphylos uva-ursi), Oregon-grape (Mahonia repens),
rose, red raspberry (Rubus idaeus), western
snowberry (Symphoricarpos
occidentalis), grouse whortleberry (Vaccinium scoparium) [226], greenleaf manzanita, pinemat manzanita
(Arctostaphylos nevadensis), and bitterbrush [276]
In Douglas-fir forests (Pseudotsuga menziesii)
[80,124], snowbrush ceanothus occurs with lodgepole pine, grand fir
(Abies grandis),
western redcedar (Thuja plicata), western hemlock (Tsuga heterophylla)
[4], vine
maple (Acer circinatum) [93], ninebark [11],
Oregon boxwood (Paxistima myrsinites) [4,93,124], bearberry [4,93], mountain snowberry,
chokecherry, currant, big sagebrush, Rocky Mountain maple, mountain-mahogany
(Cercocarpus montanus), russet buffaloberry (Shepherdia canadensis), common
snowberry [65,210], willow [65,124], Oregon-grape, Wood's rose (Rosa woodsii), white spirea [65], big
huckleberry (Vaccinium membranaceum), dwarf Oregon-grape
(Berberis nervosa), and trailing blackberry (Rubus ursinus) [93].
In mixed conifer communities [130,145,275], snowbrush ceanothus occurs with sugar pine (Pinus lambertiana)
[76,145], ponderosa pine [24,76,130,145,275], lodgepole pine [24,275], Douglas-fir
[24,76,130], incense-cedar (Calocedrus
decurrens), white fir [76,130,145], grand fir [24,145], western hemlock, western
redcedar, California red fir (Abies
magnifica),
tanoak (Lithocarpus densiflorus), Jeffrey pine
(Pinus jeffreyi), and California black oak (Quercus kelloggii) [145]. Understory associates include willow
[24,76], Oregon boxwood [130], bitterbrush,
needlegrass (Achnatherum spp.), sedge (Carex spp.) [275], common
snowberry [76], bearberry (Arctostaphylos uva-ursi) [130], manzanita [76,145,275],
chinquapin [76,130,145,275], bittercherry,
deerbrush (Ceanothus
integerrimus), mountain whitethorn (C. cordulatus) [145], mahala mat (C. prostratus) [76,145], redstem ceanothus, and pinegrass (Calamagrostis rubescens)
[24].
Snowbrush ceanothus occurs in white fir-California
red fir forests [5,88] with ponderosa pine [88,122],
Jeffrey pine [122], bush chinquapin [88],
greenleaf manzanita [88,122], mahala mat [5,122],
snowberry [5], rubber rabbitbrush, and wax currant (Ribes cereum) [122].
Snowbrush ceanothus occurs in Jeffrey pine-white fir forests
[14,34,35] with sugar pine [34], lodgepole pine [34,35], golden
currant (Ribes aureum), incense-cedar [34], mahala mat, bush chinquapin,
greenleaf manzanita [34,35], wax currant, and bittercherry [35].
Snowbrush ceanothus is a common or dominant component
in seral shrubfields of the northern Rockies [21,208,237].
Plant associates in these communities include Scouler willow (Salix
scouleriana), Rocky Mountain maple, Saskatoon serviceberry (Amelanchier alnifolia)
[21,51,120,166,208], currant
(Ribes spp.), mountain whitethorn [170], redstem ceanothus
[21,51,208],
Oregon boxwood [21,51,120,208], red
elderberry (Sambucus racemosa), russet buffaloberry [237], white spirea, common
snowberry [21,208], menziesia [21], ninebark [21,51,166,208], thimbleberry (Rubus parviflorus), bittercherry
[120,208], oceanspray [51,208], Pacific dogwood (Cornus nuttallii),
red-osier dogwood (Cornus sericea), big huckleberry, and Utah honeysuckle (Lonicera utahensis) [208].
Snowbrush ceanothus may comprise up to 80% of the shrub volume in these
communities [51].
In quaking aspen communities [16,49,50,134,285],
snowbrush ceanothus occurs with chokecherry (Prunus virginiana), mountain snowberry
[49,50], serviceberry, and
Oregon boxwood [49,50,134].
In pinyon-juniper (Pinus spp.-Juniperus
spp.) woodlands [80,147],
snowbrush ceanothus occurs with serviceberry, big sagebrush (Artemisia tridentata),
rubber rabbitbrush, green rabbitbrush (C.
viscidiflorus), green
ephedra (Ephedra viridis), bitterbrush, desert gooseberry (Ribes
velutinum), blue elderberry (Sambucus cerulea), and mountain
snowberry (Symphoricarpos oreophilus) [147].
In mountain brush communities [14,15,42,221,285], snowbrush ceanothus commonly occurs with Rocky Mountain maple
[202],
bigtooth maple [42], big sagebrush [15,42,221],
black sagebrush (Artemisia nova) [42], bearberry [14,42], ceanothus (Ceanothus spp.) [42], serviceberry
[15,42,42,44,202,221], Stansbury
cliffrose (Purshia mexicana var. stansburiana) [42], bitterbrush [15,42], snowberry [15,42,44,202,221], Oregon boxwood
[15], curlleaf mountain-mahogany [42,119], true mountain-mahogany [42], ninebark
[15,221], rubber rabbitbrush [202], oaks (Quercus spp.) [42,202,221], New Mexico locust (Robinia neomexicana) [42],
Wood's rose [202], currant [44,202],
Prunus spp. [14,15,42,44,202,221], quaking aspen [44,202], and Idaho fescue [44].
In montane chaparral communities [36,119], snowbrush ceanothus commonly occurs with manzanita
[31,36,60,119], bush chinquapin [31,36,60,119], ceanothus (Ceanothus spp.)
[31,36,119], currant [44,202], curlleaf mountain-mahogany, rubber rabbitbrush [119], silktassel (Garrya
spp.) [36], quaking aspen [44,202], oaks (Quercus spp.) [31,36,60], and Prunus
spp. [36,60,119]. Common tree species that may be present in these communities include
white fir, California red fir, sugar pine, ponderosa pine, Jeffrey
pine, and incense-cedar [36].
Plant Community Dominance:
Classifications in which snowbrush ceanothus is
identified as a plant community dominant are:
Colorado [16]
Idaho [242,243,244,245,246,247,248,249]
Nevada [162]
Oregon [130,276]
Washington [93]
Snowbrush ceanothus forms "layer groups",
or early seral shrub layers, in grand fir habitat types, co-dominating these
layers with Sitka alder (Alnus viridis ssp. sinuata), sticky
currant (Ribes viscosissum),
Scouler willow, white spirea, Utah honeysuckle, thimbleberry, Rocky Mountain maple, or
big huckleberry [242,245,247]. In Douglas-fir habitat types, snowbrush ceanothus shrub
layers are formed with pinegrass, currant, Scouler willow,
Prunus spp., serviceberry, mountain snowberry, white spirea, ninebark, or
Rocky Mountain maple [243,244,246,248,249].