Warm-Temperate Scrublands
86
133.2 Californian
Coastalscrub
Californian coastal scrub is composed mainly of low 10.2m), shallow-rooted, often aromatic, shrubs. Many species
are drought deciduous, with soft mesomorphic leaves that
2.5
desiccate and
readily
the
drought pro­
drought is severe. In
northerly, less arid communities, a tendency toward increas­
are
cast as
summer
gresses. Stem terminals may die back if
evergreenness is apparent
The major occurrence of coastalscrub is cismontane, on
low hills, foothills and valleys from sea level to the lower edge
of the chaparral at ca 300-600 m 1 Fig. 42). Much of this
former distribution is now cultivated or urbanized. Coastal­
scrub also occurs on the lower, hotter slopes of the Transverse
and Peninsular Ranges and in the inner coastal valleys and
ing
Charles P. Pase
USDA Forest Service
and David E. Brown
Arizona Game and Fish
Department
foothills 1 e.g., Perris
Valley). There coastalscrub may reach
higher, occupying a position immediately below the
chaparral (Fig. 43). Its intergradation and contact with
Californian valley grassland is frequently distinct and marked
by a narrow, nonvegetated band (Muller et a1., 1964; Halligan,
1974). Southward it merges gradually with the Vizcaino
subdivision of the Sonoran Desert Its only other major
800
m or
with the Sonoran Desert is with the Lower Colorado
subdivision in the Banning-Cabazon vicinity where the
transformation in San Gorgonio Pass just east of Cabazon is
contact
abrupt
Examination of
precipitation data from stations within
of Californian coastalscrub shows mean annual totals as
high: as 400 mm in one of the higher intermountain localities
to as low as 125 mm near its southern limit, along the coast of
Baja California Norte (Table 9). Most coastalscrub receives
less than 300 mm per annum, and is significantly drier than
the higher chaparral communities. All localities receive 90%
or more of their precipitation during the October- April period
and, except for lower precipitation and higher summer
temperatures, climatographs of coastalscrub stations are
similar to those of Californian chaparral 1 Figs. 44, 45).
Characteristic species include California Sagebrush
(Artemisia californica), White and Black Sage (Salvia apiatia, S.
mellifera), Whiteleaf Sage ISalvia leucophylla), California
Buckwheat (Eriogonum fasciculatum), California Encelia
(Encelia californica), Lemonade Sumac (Rhus integrifolia),
Southern Monkey Flower (Mimulus longiflorus), Sawtooth
and Damiana Goldenweed (Haplopappus squarrosus and H.
venetus), Our Lord's Candle (Yucca whipplei) and Golden
Yarrow (Eriophyllum confertiflorum) [Munz and Keck, 1949;
Horton, 1960). Many herbaceous species are present, particu­
larly after fires. Occasional widely-spaced individuals more
characteristic of the higher, moister chaparral may be found­
Sugarbush (Rhus ovata), California Scrub Oak (Quercus
dumosa), Hollyleaf Cherry (Prunus ilicifolia), and Mountain­
mahogany (Cercocarpus betuloides), but these add little to the
generally short (0.3-1 m) crown cover of the type (Fig. 46).
areas
Southward toward El Rosario (and to a lesser extent
eastward), an increasing number of basically desert species
become important in the makeup. Especially noticeable are
Burbush IAmbroisia chenopodifolia), Coffeeberry or Ioioba
(Simmondsia chinensis), Desert Apricot (Prunus fremontii),
Maguey (Agave shawii), Silver Cholla (Opuntia echinocarpa),
Beavertail Prickly Pear IOpuntia basilaris) and Pitaya Agria
(Stenocereus gummosus). The passage from coastalscrub to
Sonoran desertscrub is a gradual one, but becomes increas­
ingly evident south of Ensenada (Shreve 1936b). This transi­
region in northern Baja California also contains a
number of endemics such as Parry Buckeye IAesculus parryi),
tion
Figure 42. Californian coastalscrub just north of Dana Point, Orange County, California, ca. 15 m
elevation. High bluffs here separate the coastalscrub of sage, buckwheat, sumac (right center), and other
species from the coastal strand, minimizing the usual integration between these two California biomes.
Figure 43. Californian coastalscrub near Sage, Riverside County, California, ca. 640 m elevation.
Eriogonum fasciculatum, Simmondsia chinensis, Rhus ovata, Salvia apiana, and a host of herbaceous
annuals and perennials in this xeric "interior" [asciatioti reminiscent of Sonoran desensctub-semidesett
grassland transition.
Warm-Temperate·Scrublands
88
Table 9. Precipitation data from 15 stations in the Southwest in
(in m)
Newport Beach, CA
adjacent
Californian Coastal scrub.
to
M_e_a_n_m_o_n_t_hl_y_p_re_c_ip_it_a_tio_n_in_m_m
Elevation
Station
or
F
M
A
M
A
_
S
o
N
D
Total
Total
Oct. thru
Percent
April
of total
3
53
55
41
33
4
0.3
0.8
4
7
39
44
282
272
96
4
48
38
39
21
4
.8
2
3
9
32
44
242
231
95
3
49
54
41
20
5
0.8
.3
3
4
12
22
54
265
252
95
186
60
55
43
27
5
.5
2
5
7
38
46
290
276
96
256
46
44
39
26
5
.8
3
5
8
30
43
252
236
94
343
79
73
62
41
11
3
3
8
13
49
66
409
383
94
402
59
52
53
34
9
2
2
4
8
12
39
50
324
299
93
392
56
49
42
22
3
.5
.5
3
4
7
36
50
273
262
96
468
51
49
50
30
6
3
6
8
13
36
44
297
273
92
515
78
28
47
25
10
2
3
3
12
16
41
267
247
93
150
52
29
35
23
2
8
23
38
213
208
98
105
45
26
25
21
2
0.1
2
6
22
32
183
177
97
100
26
25
13
0.3
.3
6
6
21
34
134
126
95
El Socorro, BCN
115°49'
10
47
22
13
7
0.3
7
15
25
138
136
99
Santa Maria
30
27
25
14
11
.2
7
8
36
134
138
98
117°53'
33°36'
San
Diego, CA
117°10'
32°44'
Chula Vista, CA
117°06'
3r36'
Corona,
CA
33°53'
117°33'
Riverside,
San
CA
Bernardino,
CA
117°16'
34°08'
Redlands,
CA
117°11'
34°08'
Elsinore,
CA
33°40'
117°20'
San
Jacinto, CA
116°58'
33°47'
Tecate, BCN
3r35'
116°38'
Santo
Tomas, BCN
31°32'
116°25'
San
Vicente, BCN
30°59'
San
2
117°23'
33°57'
116°06'
Telmo,
30°59'
2
BCN
.3
116°06'
30°20'
.3
del Mar, BCN
30°26' 115°54'
25.0
(,J
20.0
(,J
o
o
w
a::
:J
w
�
ffi
a::
:J
l­
e
15.0
ffi
a..
:E
w
I-
w
I-
January
�
�
10.0
�
z
10.0
January
z
o
o
:E
:E
z
e
e
z
w
:E
15.0
a..
:E
;:
20.0
w
5.0
:E
2
3
4
:s
6
7
MEAN MONTHLY
8
9
PPT
(em)
10
II
12
Figure 44. Monthly precipitation-temperature polygon for
Californian coastalscrub (six stations).
51l
2
3
4
5
MEAN
6
7
MONTHLY
8
9
PPT
(em)
10
II
12
45. Monthly precipitation-temperature polygon for
Californian chaparral (seven stations).
Figure
46. Californian coastalscrub near lulian, San Diego County, California, ca. 825 m elevation. The
"patterning" effect with chaparral and woodland is due to variations in available plant moisture,
evapotranspiration rates, and possibly fire history. The primary coastalscrub species here is Eriogonum
Figure
fasciculatum.
a wild rose (Rosa minutifolia), Chaparral Ash (Fraxinus trifol­
iatal, Siemprevivos (Dudleya spp.1 and the Velvet Cactus
(Bergerocactus emoryi, Fig. 471. The appearance of a buckeye
desert scrub.
in such
the Great Basin and these of Californian derivation.
Among the vertebrates, reptiles best distinguish this biome
an arid region is surprising.
species readily sprout after burning, and this, coupled
with the general abundance of herbaceous plants, permits
rapid recovery after fires. On better sites, complete recovery
Most
may take
as little as 10 years, but on poor sites recovery may
take much longer. After fires at higher elevations, coastal­
scrub is often a successional stage to chaparral.
The cover in mature stands is generally more open than in
the adjacent chaparral, owing to the generally poorer site
conditions and lower rainfall in coastalscrub. Ground cover
of less than about 50% is common and may not exceed 25%
on steep or unstable slopes.
Although Californian coastal scrub can be considered as the
ecological center for several mammals and birds- e.g., the
Nimble Kangaroo Rat (Dipodomys agilisl, San Diego Pocket
(Perognathus fallaxl, and California Valley Quail
(Lophortyx californicusl- it also provides suitable habitats for
a number of species adapted to both open chaparral and
Mouse
Also, as an expression of vegetational affinities,
sagebrush species, such as the Sage Sparrow (Amphispiza
bellil do not differentiate between sagebrush communities of
some
evolutionary center, although a relatively recent one.
Centered here are the: California Side-blotched Lizard (Uta
stansburiana elegansl, San Diego Coast Horned Lizard (Phry­
nosoma corona tum blainvilleil, Coastal Whiptail (Cnemi­
dophorus tigris rnunzius], Orange-throated Whip tail (Cnemi­
dophorus hyperythrus], Coastal Rosy Boa (Lichanura ttivitgata
roseofuscel, California Striped Racer (Masticophis lateralis
lateralisl, Coast Patch-nosed Snake (Salvadora hexalepis vitgul­
teal, San Diego Gopher Snake (Pituophis melanolecus annec­
tans I, California Glossy Snake (Arizona elegans occidentalisl,
San Diego Night Snake (Hypsiglena torquata klauberil, South­
ern Pacific Rattlesnake (Crotalus viridis helleri), and the Red
Diamond Rattlesnake (Crotalus ruber). The fact that these
taxa are mostly of sub specific rank further attests to the
recent differentiation of Californian coastal scrub, contem­
porary with the Southwest's deserts.
as an
Warm-Temperate Scrublands
90
Californian coastalscrub on Isla Todos Santos, Baja California Norte, ca. 6 m elevation, April,
profusion of herbaceous vegetation makes the term "soft chaparral" seem especially appropriate
here in this southern fasciation after the wet winter of 1978-79. The perennial shrubs, principally Encelia
californica and Salvia spp., are actually rather widely spaced with several=desert" species now
inconspicuously present- Bergerocactus emoryi, Opuntia prolifera, and Dudleya, spp.
Figure
47.
1979. The