BOTANICAL RESOURCES
THE FLORA
There are 512 vascular plant entities documented from Hollister Ranch (see Appendix 1,
Annotated Catalogue of Vascular Plants), including various subspecies, varieties, and
several hybrids. These entities represent 7 families of ferns and fem allies; 66 families of
dicots, and 66 families of monocots. There are at least 304 genera represented in the flora,
and 497 species. The total of 84 plant families found here is an impressive 49% of the 173
plant families found in the California flora. Twenty-five percent of the plant genera found
in California are represented on the ranch by one or more members, and 8% of the species
found in California occur here. These figures reflect the botanical richness of the Ranch,
given that the land area of the ranch is only about 1/100 of 1% of the total land area of the,
state.
The plant families represented by the greatest number of entities are the Aster Family
(Asteraceae), with 90 taxa; the Grass Family (Poaceae), with 60 taxa; and the Legume
Family (Fabaceae) with 39 taxa. Of the 497 species that are known to occur on the ranch,
352 (72%), are native to California. The overall proportion of natives in the California
flora, according to the Jepson Manual (Hickman 1993) is 83% of the 5862 species reported
for the state. Species endemic to California make up ca 24% of the total for the state. The
high proportion of exotic species at Hollister Ranch (26%), compared to California as a
whole (17%), reflects the numbers of weedy species generally confined to the disturbed
coastal plain, annual grasslands, and disturbance sites and corridors such as residential
areas and roadside margins.
Species of Special Interest. Species of special interest (Table 1) are those plants
listed as threatened or endangered by the U.S. Fish and Wildlife Service, the State of
California, or the California Native Plant Society, or are considered of interest or
biologically sensitive because they are declining in occurrence or abundance, are at or near
the limits of their geographic range, or are endemic to the general region in which Hollister
Ranch occurs (see Wiskowski 1988). Thirty-eight plant taxa at Hollister Ranch are
considered to be species of special interest (Table 1). Refer to Biogeographic Analysis
for information regarding those species of special interest that occur at or near the limits of
their range.
Representative Botanical Areas of Note. With the assistance of the Hollister Ranch
Conservancy, we have developed a map of the Ranch's "Representative Botanical Areas of
Note" (see Table 2 at the end of this section, and Fig. 7). The forty-seven areas are
referenced because one or more of the following attributes: (1) importance for individual
species of special interest; (2) association of various species of special interest; or (3) rarity,
importance, or representative aspect of particular habitats (e.g., wetlands and riparian corridors).
The map and accompanying tabular explanation are provided for use regarding
conservation, management, and research opportunities at the Ranch.
VEGETATION
Upland Plant Communities of Hollister Ranch
The number and variety of plant communities are a key element in the botanical
diversity of Hollister Ranch. There are eleven distinct plant communities or vegetation
types (plus a few mixed types) delineated on the vegetation map prepared for this study
(Fig. 6). In addition, there are some important plant communities, particularly wetland
types, that could not be mapped either because they are very small in area or do not show
up on the aerial photographs. An example is the perennial grassland type, which is included
under the general "grasslands" vegetation on the map. We will describe both the mapped
vegetation units and the equally important plant communities that do not appear on the
vegetation map.
Even the casual observer will notice that transitions from one type of vegetation to
another quite different type can be surprisingly abrupt. This is due to the complex geology
of the Ranch, as can be seen from a comparison of the geology (Fig. 4), soils (Fig. 5) and
vegetation (Fig. 6) as well as in the aerial photographs (Fig. 3). Undulating grasslands run
into a wall of chaparral, marking the change in the underlying bedrock. More subtle
transitions also occur however, such as the change from a coastal scrub community
dominated by California Sagebrush and Bush Sunflower in the lower eastern canyons, to
one dominated by Purple Sage in the canyons from San Augustin and to the west. We will
explore some of the factors that may be at work in causing these shifts in dominance type
within plant communities.
It is worth noting that, although the terms "vegetation type" and "plant community" are
used here interchangeably, there is an underlying subtle distinction. "Vegetation type" is a
descriptive term regarding plants structure and composition. "Plant community", on the
other hand, is more evocative of the interactions between the plants and their environment,
and of the ecological functions of the communities. In the following descriptions, the "community"
aspects are highlighted.
Annual Grassland. Annual grasslands are generally found on south-facing slopes or
terraces with clay soils. There are several annual grassland types on the Ranch, depending
on the soil type, slope, and grazing intensity. Probably the largest in area is the type found
on clay loams of the Rincon formation. Total grassland acres are estimated to be 5312
acres, or about 36% of the total acreage of the ranch.
Rincon formation grasslands are typically dominated by one or two introduced annual
grasses such as Soft Chess (Bromus hordeaceus), Ripgut Brome (Bromms diandrus),
Foxtail Barley (Hordeum murinum), or Wild Oats (Avena spp.). These grasslands provide
important forage for grazing, but are relatively uninteresting from a botanical point of view.
They are the least diverse habitats on the Ranch, with the highest percentage of non-native
species. Some slopes, for example in Alegria Canyon, can be dominated by dense Black
Mustard (Brassica nigra). The brilliant-yellow springtime floral display may be pretty, but
black mustard is nonetheless a weed that often excludes native plants.
Grasslands that are less grazed, such as those near the ridges, typically support more
diversity and a higher proportion of native annuals and perennials. Associated plants
include Owl's Clover (Castilleja exerta), California
Filago (Filago californica), Narrow-
leaved Filago (Filago gallica), Bishop's Lotus (Lotus strigosus), California Plantain
(Plantago erecta), Catalina Mariposa Lily (Calochortus catalinae), Purple Needlegrass
(Nassella pulchra), Golden Stars (Bloomeria crocea), Holly-leaved Navarretia
(Navarretia atractyloides), Sharp-toothed Sanicle (Sanicula arguta), Blue-eyed Grass
(Sisyrinchium bellum), Blue Dicks (Dichelostemma capitatum), and Brodiaea (Brodiaea
jolonensis).
Another diverse annual grassland type is found on the sandy loam soils of the marine
terrace. Take a closer look at the brilliant wildflower displays that sometimes appear under
optimum spring rainfall conditions. The aptly named
Goldfields (Lasthenia californica
can turn the fields bright-yellow along Rancho Real near Panochas. Also conspicuous are
Tidytips (Layia platyglossa) with yellow petals tipped by white, Purple Owl's Clover
(Castilleja exserta), Red Maids (Calandrinia ciliata), and Bird's Foot
Trefoil (Lotus
salsuginosus). Lupines (Lupinus nanus and L. bicolor) poke their blue spikes above the
green grasses. Other native annuals found in the common areas along the road include
White Popcorn Flower (Plagiobothrys californicus), Fiddleneck (Amsinckia menziesii),
Golden Stars (Bloomeria crocea), and Blue Dicks (Dichelostemniacapitatum).
In the past (see Land Use History), fire was used on the Ranch as a
management tool to increase the extent of grasslands and improve grazing. With reduced
fire incidence and lower grazing intensity, some grasslands are undergoing a successional
change towards a coastal scrub community. These types have increasing densities of Coast
Goldenbush (Isocoma menziesii), Saw-toothed
Goldenbush (Hazardia squarrosa), and
California Sagebrush (Artemisia californica). Such areas are indicated on the vegetation
map as a grassland/coastal scrub community (Fig. 6).
Perennial grasslands. We will never know what a native perennial grassland looked
like prior to the settlement of Europeans in California. Almost all grasslands in California
have been invaded to a greater or lesser extent by Mediterranean annual species; the ones
we call "native perennial grasslands" are those that support a significant cover of native
bunch grasses along with the annual non-native species. Because native grasslands could
not be distinguished from annual grasslands on the aerial photos, we could not determine
their current extent on the Ranch. Perennial grasslands typically occur at higher elevations
and along the ridges, on moderate to gentle slopes with good topsoil development. An
excellent example of a native grassland is located on the slope above Del Norte, near the De
la Cresta intersection. Coastal terrace examples do occur, however, such as west of the
Bulito Cabana and east of Honda Canyon. These perennial grasslands are often a mix of
Purple Needle Grass (Nassella pulchra) and California Barley (Hordeum brachyantherum
ssp. californicum). In April and May the tall, graceful flowering stems of the grasses
move with the wind, bearing slender, long-awned seeds.
Perennial grasslands typically support a high diversity of native perennial and annual
species, including those found in annual grasslands (see above). Cover of perennial grasses
is usually between 20% and 50%. The most common dominant native grass is Purple
Needlegrass, although Foothill Needlegrass (Nassella lepida) is common at some sites
such as grasslands in Bulito Canyon. Other species typical of perennial grasslands include
Soaproot (Chlorogalum pomeridianum), Chocolate Lily (Fritillaria biflora), Bluegrass
(Poa secunda), Coast Range Melic (Melica imperfecta), Big Grindelia (Grindelia
camporum), Death Camas (Zigadenusfremontii), Blue-eyed Grass (Sisyrinchium bellum),
Winecup Clarkia (Clarkia purpurea), and Checkerbloom (Sidalcea malva@flora).
Heavy grazing and cultivation practices in the past are thought to have contributed to the
decline of perennial grasses throughout California. However, these grasslands appear to be
increasing on the Ranch with improved grazing management (see section V, Management
Opportunities). Perennial grasslands are considered a sensitive vegetation type due to their
relative rarity (Fig. 7), and should be protected whenever possible.
Coastal Scrub. Coastal scrub vegetation (i.e., coastal sage scrub) occurs on dry slopes
with poor, often rocky soils. In some cases it may be a "successional" community; that is
to say, an intermediate phase, following fire or some other disturbance, that eventually
leads to the development of chaparral or oak woodlands. In other areas it is simply the only
vegetation that will survive, given the local environmental conditions. Coastal scrub
vegetation is common on the Ranch, covering about 2250 acres or about 15% of the land
area. If we include those areas that are transitional between grassland and coastal scrub
(shown as grassland/coastal scrub) the figure rises to 3466 acres, or about 24 % of the
land area (Fig. 6).
You will be able to distinguish coastal scrub vegetation by its color and texture, which
are different from another shrub community on the ranch: chaparral. Coastal scrub species
are often partly deciduous during the dry part of the year, and as a result of this and other
drought adaptations the vegetation has a soft texture and muted colors of gray and gray-
greens. At the Ranch, it is often less than three feet high, and despite its diversity of
dominance types, richness of associated plant species, and function as habitat for wildlife,
the importance of coastal scrub is often overlooked.
There are many variations on the coastal scrub theme that occur on the Ranch; we will
attempt to mention a few of the major ones here. A common denominator is California
Sagebrush (Artemisia californica), whose soft, aromatic gray foliage is as ubiquitous as it
is overlooked in the California coastal landscape. Associated species can vary with soil type
and/or slope aspect. The effect of slope aspect is noticeable at Panochas, for example,
where the cast-facing slope at the canyon mouth is dominated by Giant Wild Rye (Leymus condensatus)
and Poison Oak (Toxicodendron diversilobum); whereas the corresponding
west-facing (hotter and drier) slope has more Bush Sunflower (Encelia californica) and
Coyote Brush (Baccharis pilularis).
Substrate (rock or soil type) is a major factor in determining the species composition of
all vegetation types. Species on the harder, less eroded Alegria formation, for example, are
different from those on the softer, weathered Rincon or Sisquoc shales. The rockier sites
tend to have a sparser cover, with species such as California Buckwheat (Eriogonum
fasciculatum), Bricklebush (Brickellia californica), Lemonadeberry (Rhusintegrifolia),
and the Succulent Live-forever (Dudleya lanceolata), in addition to California
Sagebrush
Also observe the change in coastal scrub species as you travel from east to west along
Rancho Real. In the vicinity of San Augustin, the vegetation color changes as the dominant
species change from the green-gray of the plants typical at Panochas and other eastern
canyons California Sagebrush, Poison Oak, Giant Wild Rye, and Bush Sunflower
- to a
community dominated by the whitish aromatic foliage of Purple Sage (Saivia leucophylla).
In Gato Canyon, you may notice the yellow flowers or inflated pods of
Bladderpod (Isomeris arboreal),
a shrub of the caper family that on the Ranch occurs only in the
western canyons. The abrupt change in coastal scrub composition is not explained by rock
formation or soil type in this case, because these are the same for both dominance types.
Climate may provide a clue, however, because the more westerly canyons are apparently
somewhat drier.
A subtype of the coastal scrub is Coyote Brush (Baccharis pilularis) scrub. It consists
almost entirely of this one species, with little understory development in the denser stands.
There are about 27 acres of Coyote Bush scrub on the Ranch. It favors coastal sites with
high soil moisture, as along drainages and near estuaries. The higher flood plain habitat at
the Santa Anita Estuary is covered by dense Coyote Bush Scrub.
Another type of coastal scrub vegetation is present on the Ranch, although restricted in
area. This is the coastal bluff scrub, which clings to the cliffs above the beaches and
estuaries. The relatively unstable cliffs do not allow much of this vegetation to develop, and
the patches are too small to map. Plants in this community are adapted to a harsh
environment of desiccating winds, salt, and intense sun. Quail Bush or Coastal Saltbush
(Atriplex lentiformis) is often a dominant shrub along the immediate coast. Woolly
Scablite (Suaeda taxifolia), a species of special interest (Table 1) is restricted to this
community and is rare at Hollister Ranch.
Chaparral. Chaparral is the general name for the evergreen shrub vegetation that
blankets many California slopes. This tough community thrives on steep, rocky sites with
poor or no topsoil, and its often dense shrub cover permits little understory development.
There are about 3011 acres of this vegetation type on the Ranch; covering about 20% of the
land area (Fig. 6).
From February to April is one of the best times to observe chaparral, when the masses
of delicate, fragrant ceanothus and manzanita blossoms appear early in the year. Bees are
attracted to the sweet-smelling flowers (another name for ceanothus is "mountain lilac").
At other times of year the vegetation can appear strikingly homogeneous, dominated by a
few species that seem to merge into a continuous dark green canopy of even height.
A deeper appreciation of the chaparral can be gained by learning about its ecology,
which includes a cycle of periodic destruction and rebirth. Shrubs compete with one
another for light and moisture, so older stands become very tall with lots of dead branches
under the canopy. The dry, resinous wood of chaparral is readily flammable, and familiar
to many Californians is the sight of flames roaring up chaparral-covered slopes. The fires
seem catastrophic to the casual observer; however, fire is a part of the natural cycle for this
community. Chaparral plants have evolved adaptations to fire, including storage burls
which resprout within a matter of weeks, and seeds that require heat and/or leachate from
charred wood in order to germinate. The chaparral community will recover from fire
astonishingly quickly -- within a few years the cover is complete.
Meanwhile, the diversity that is not apparent in the mature chaparral stands bursts forth
after a fire, as seeds of annual and perennial herb species that have lain dormant in the soil
for decades germinate and grow. After a fire is the time to look for plants such as Sticky
Phacelia (Phacelia viscida), Golden Eardrops (Dicentra ochroleuca) and other flowering
plants that appear following a fire.
The fire cycle benefits chaparral by removing old, senescent shrubs and allowing
recruitment of new ones. Wildlife habitat is also improved as the structural and species
diversity of the habitat increases following a fire. Controlled bums have often been used as
a fuel management technique in chaparral; however, residential development limits the use
of this toot where there is a potential for property damage from a bum that escapes control.
Chaparral on Hollister Ranch is dominated by a few shrub species, which vary in their
relative importance according to the rock substrate and other less obvious factors. Some
areas are heavily dominated by Bigpod Ceanothus (Ceanothus megacarpus); these seem to
be primarily in the eastern canyons (Alegria and Agua Callente) on sandstones of the
Vaqueros and Gaviota formations. Chamise (Adenostomafasciculatum) is often the
dominant shrub in chaparral on the Alegria Formation. Matilija sandstones appear to favor
manzanitas, the two most interesting species (see Table 1) being Purisima Manzanita
(Arctostaphylos purissima) and Refugio Manzanita (A. refugioensis). These species are
difficult to distinguish, and the Hollister Ranch populations need additional consideration
(see section V, Management Opportunities). Other common chaparral species include
Buckbrush (Ceanothus cuneatus), Chaparral Pea (Pickeringia Montana), Black Sage
(Salvia mellifera), and Toyon (Heteromeles arbutifolia). Scattered Coast Live Oaks are a
frequent component of the chaparral community, as are Bush Poppy (Dendromecon
rigida),
Coffeeberry (Rhamnus californica), Woolly Coffeeberry (Rhamnus tomentella),
Redberry (Rhamnus crocea) and Mountain Mahogany (Cercocarpus betuloides).
In the chaparral along De la Cresta, you can observe several of the "special" ranch plants
such as Summer Holly (Comarostaphylis diversifolia), Santa Cruz Island Oak (Quercus parvula),
Zaca Manzanita (Arctostaphylos glandulosa var. zacaensis), Salal (Gaultheria shallon),
Lompoc Monkeyflower (Mimulus aurantiacus ssp. lompocensis) and the
endangered Lompoc Yerba Santa (Eriodictyon capitatum). Several sensitive species of
ceanothus occur sporadically in chaparral on the Matilija sandstone: Dwarf Ceanothus
(Ceanothus dentatus), Warty-leaved Ceanothus (Ceanothus papillosus var. papillosus),
and Blue Brush (Ceanothus thyrsiflorus). We include this chaparral within the Ranch's
"Botanical Areas of Note" (Fig. 7).
Openings and disturbances in chaparral allow annual and perennial herbs to thrive.
Along De la Cresta, look for the annual Saint's Daisy (Erigeron sanctarum); it is a regional
endemic species with yellow central disk flowers and violet rays. Showy yellow flowers of
the gumplant Big Grindelia (Grindelia camporum) are easy to spot in early summer; so are
the red and yellow spikes of Woolly Indian Paintbrush (Castilleja foliolosa), Red Indian
Warrior (Pedicularis densifora), and the silvery-gray foliage of Cudweed Aster
(Lessingia filaginifolia).
Oak Woodland/Oak Forest. Oak woodlands and forests occur mainly on the
protected sides and floors of canyons and on north-facing slopes with deep, loamy soils.
There are about 597 acres of oak woodland and 86 acres of oak forest on the Ranch, along
with 283 acres of mixed coastal scrub/woodland, and 340 acres of chaparral/woodland.
The total oak habitat thus comprises about 1306 acres of Hollister Ranch, or about 9% of
its land area (Fig. 6). The two types (woodland and forest) differ mainly in the amount of
tree canopy cover. Forests have continuous canopy cover, whereas woodlands vary in their
canopy cover from very open to almost complete cover. Both are dominated by Coast Live
Oak (Quercus agrifolia). Understory vegetation varies depending on the amount of
sunlight that gets through the oak canopy. Flat, relatively open sites on valley floors tend to
have an annual grassland understory that may be maintained by grazing, whereas steeper
slopes with greater canopy closure support various shrubs, ferns and grasses, sometimes
in a very dense understory. For an example of the latter type of understory, look to the
slopes of upper Bulito Canyon. The twisted trunks of the oaks and the filtered sunlight
produce a cathedral-like effect.
One of the most common plants in this community is one that everyone should be able
to recognize: Poison Oak (Toxicodendron diversilobum). Its three-part leaves are green in
spring, then turn to shades of yellow and red in late summer and fall, but the irritating oil
they contain is present at all times, and even contact with the bare stems during winter can
produce a rash in susceptible persons. Poison oak can be distinguished from blackberry
(Rubus ursinus), which also has three-parted leaves and occurs in the same habitat, by the
thorns that blackberry has on its stems. Other understory species are Sword Fern
(Polystichum munitum), Hummingbird Sage (Salvia spathacea), Humboldt Lily (Lilium
humboldtii ssp. ocellatum), Wood Fern (Dryopteris arguta), Mugwort (Artemisia
douglasiana), Snowberry (Symphoricarpos mollis), Bedstraw (Galium spp.), Giant Wild
Rye (Leymus condensates), and Miner's Lettuce (Claytonia perfoliata). In addition to
Poison Oak and Blackberry, few shrubs do well in the shady understory; among those that
occur here are Coffeeberry (Rhamnus californica) and Toyon (Heteronwles arbutifolia).
Oaks in general are valuable for their functions such as wildlife habitat and their values
such as their aesthetic beauty. In many cases, various species of oak are in decline in
California. Even at Hollister Ranch, few young trees and saplings occur at some sites,
particularly in the open, grassy type of woodlands on the canyon bottoms. This lack of
reproduction has been attributed to various factors in California, including impacts from
feral animals such as pigs, grazing by cattle, competition for resources among oak
seedlings and annual grasses, climate changes, and other factors. Protection and
enhancement of oak habitats is an important priority for the preservation of the natural
environment of the Ranch.
Tanbark Oak Forest. There are about 84 acres of Tanbark Oak forest on the Ranch,
plus about 28 acres of mixed chaparral/tanbark oak; less than 1% of the total land area (Fig.
6). Still, it is one of the most interesting communities from a biogeographical standpoint,
and is included as a Hollister Ranch "Botanical Area of Note" (Fig. 7). Most of the stands
are on the north-facing crest of the Matilija formation, along De la Cresta.
Many plants in this community are ones that are common in northern California and
even southern Oregon forests, reaching their southern distribution limit in the Santa
Barbara area. Entering the forest, one feels suddenly transported more than a hundred
miles north, to the moist, lush coastal forests of the Santa Lucia Mountains in Monterey
County. The dominant tree, Tanbark Oak (Lithocarpus densiflorus), and many of the
understory shrubs and herbs such as Sword Fern (Polystichum munitum), Huckleberry
(Vaccinium ovatum), Thimbleberry (Rubus parviflorus), Alum Root (Heuchera
pilosissima), Salal (Gaultheria shallon), Wake Robin (Trillium angustipetalum),
Wax Myrtle (Myrica californica), and Blue Brush (Ceanothus thyrsiflorus) are unexpected, and
more common to the northern and central coast than to our area. Other understory plants
are those of our local oak woodlands, such as Blackberry (Rubus ursinus), Bracken Fern
(Pteridium aquilinum), Poison Oak (Toxicodendron diversilobum), and Hedge Nettle
(Stachys bullata). This is the only place on the Ranch where we found Barberry (Berberis pinnata),
which is also most common to the north of here, although it ranges down to Baja
California (apparently at higher elevations).
Beach and Dune Vegetation. Although almost 80 acres are mapped as Beach/Dune
vegetation (Fig 6), most of Hollister Ranch's sandy shoreline is so shifting and narrow that
stable dunes don't have an opportunity to form. Several species typical of foredune
vegetation can be found in limited areas at Augustin, Bulito, and Drakes, including Sticky
Sand Verbena (Abronia maritima), Sea Rocket (Cakile maritima), Beachbur (Ambrosia
chamissonis), and Sea-scale (Atriplex leucophylla).
Many dune plants are notable for their ability to colonize bare sand habitat, adapting to
the various stressful conditions, such as high salt of beach sands, reflected heat, and the
blowing sand that tends to bury their leaves. Given time these pioneering species colonize
bare beach sand and create dunes. You can observe the beginnings of this process as sand
accumulates around the clumps of vegetation, which then produce more growth that will be
covered with more sand, and so on. The Ranch's sandy beaches are relatively small, so
these nascent dunes generally are washed out by storms before they develop to stabilized
due habitat.
Wetlands at Hollister Ranch
Four of the five major wetland systems (Marine, Estuarine, Riveline, and Palustline)
are represented at Hollister Ranch. Lacustrine wetlands, or those associated with shallow
margins and shorelines of lakes, do not occur at Hollister Ranch. Although generally
limited in size and occurrence, wetlands at the Ranch are diverse in types and rich in
composition. Eighteen riparian corridors (Fig. 6) and their associated streams drain
watersheds at the Ranch (see section 1, Fig. 3), providing a major contribution to the
frequency of wetland occurrences and types.
Hetcher (1983) provided an overview of the various wetland types. A classification
methodology for wetlands of central and southern California has been developed by Ferren
et al. (1995, 1996), and they included selected examples from Hollister Ranch. The many
wetland habitats resulting from site differences in bedrock geology, exposure, hydrology,
and water chemistry support a rich wetland flora and vegetation. However, much
additional work on the classification, inventory, and mapping of the Ranch's wet land
heritage is warranted (see section V, Management Opportunities).
Marine Wetlands. Marine wetlands occur along intertidal zones where the open ocean
overlies the continental shelf and the adjacent coastline. Water regimes are determined by
oceanic tides and salinities from sodium chloride exceed
30% (parts per thousand). Along
the nearly 20 mile coast of Hollister Ranch, marine wetlands are well represented by four
classes: Marine Rocky-Shore Wet land, Marine Unconsolidated-Shore Wetland, Marine
Aquatic-Bed Wetland, and Marine Reef Wet land, which is dominated by attached
invertebrate animals. The aquatic-bed class is the only marine wetland type dominated by
vegetation. Subclass rooted-vascular is characterized by flowering plants, whereas subclass
algal is characterized by various green, brown, and red algae.
At various sites, such as exposed bedrock from eroded headlands at the Ranch, Marine
Aquatic-Bed Rooted-Vascular Wetlands occur, which are dominated by Surf Grasses
(Phyllospadix torreyi and P. scouleri). Eel Grass (Zostera marina) is commonly found
washed up along the beaches, but in this marine environment it is typically attached to
substrates that are subtidal, and thus the species occurs in deepwater habitats rather than
intertidal wetlands. Representative examples of vegetated marine wetlands occur within the
Hollister Ranch Shoreline Preserve, which extends from the eastern boundary of the
Ranch, westward to about 0.5 miles west of Alegria Beach. We include various
biologically rich examples of marine wetland as "Representative Botanical Areas of Note"
(Fig. 7).
Estuarine Wetlands. Estuarine wetlands include intertidal zones in coastal
embayments (estuaries) that have at least occasional access to the ocean, and thus water
with ocean-derived salts enter with tide waters, and in which the saline ocean water is at last
occasionally diluted by freshwater runoff from the adjacent land.
Emergent portions of the southern California coastline are often characterized by a
series of incised, parallel canyons that drain watersheds from the adjacent landscapes.
These canyons empty into the ocean through small estuaries that are quite variable in size,
frequency of tidal flushing, salinity regimes, and biota. Other types of estuaries in the
region include, for example, river mouths, structural basins, and bay estuaries. There are
ten estuarine wetland classes, some of which do not occur at Hollister Ranch (e.g., class
forested wetlands which is dominated by mangroves). Classes of wetlands dominated by
vascular plants in estuaries at Hollister Ranch include Estuarine Aquatic-Bed Wetlands,
Estuarine Emergent Wetlands, and Estuarine Scrub-Shrub Wetland.
Along the coast of Hollister Ranch, several of the canyon-mouth estuaries (e.g., Aqua
Caliente, Alegria, and Santa Anita estuaries) contain small lagoons that are at least
seasonally-impounded at their mouths by sandbars. They are generally characterized by
brackish water conditions because of relatively perennial stream flows or groundwater
seepage. Indicators of the prevailing brackish-water condition at the Santa Anita Estuary
are a rooted-vascular plant, Spiral Ditchgrass (Ruppia cirrhosa) that forms aquatic-bed
wetlands; and an estuarine-endemic fish, Tide Water Goby (Eucyclogobius newberryi),
which is an endangered species. These two species generally occur in the same types of
estuaries, but are not found in estuaries characterized by extensive salt marshes, where
salinities tend to approximate marine conditions most of the year.
Estuarine Emergent Wetlands in regularly-flooded to irregularly-exposed channel
habitats are generally dominated by bulrushes such as California Bulrush (Scirpus
californicus) and Salt Marsh Bulrush (Scirpus maritimus). Estuarine Emergent Wetlands
associated with high marsh habitats are often dominated by a series of persistent,
rhizomatous perennials such as Salt Grass (Distichlis spicata) and Alkali Ryegrass
(Leymus triticoides). Nonpersistent emergent vegetation, which can occur in Estuarine
Unconsolidated-Shore and Unconsolidated-Bottom Wetlands (e.g., exposed mud flats and
sandbars), are often characterized by annual species such as Spear Oracle Saltbush
(Atriplex triangularis). At Hollister Ranch, Estuarine Scrub-Shrub Wetland is infrequent
because of the lack of well-developed habitat. However, examples can develop and are
usually characterized by Salt Marsh Baccharis (Baccharis douglasii) and Coast Saltbush
(Atriplex lentifornus).
Riverine Wetlands. Riverine wetlands occur within channels that are influenced
strongly by the energy of flowing water. Riverine wetlands do not include stands of
persistent vegetation such as trees, shrubs, and some forms of emergent (i.e. emergent
herbaceous or non-woody) vegetation. They also exclude wetlands in channels (e.g.,
intertidal estuarine channels) with ocean-derived salinity in excess of 0.59%. Seven classes
of riverine wetland occur in southern California. Although vascular plants can occur in all
of them, biotic classes dominated by plants include Riveiine Aquatic-Bed Wetlands and
Riverine Nonpersistent Emergent Wetlands.
Riverine wetlands at Hollister Ranch occur in streambeds, canyon bottoms, and washes
and are among the types of freshwater wetlands that characterize the area. However, some
of these types are characterized by water-chemistry (e.g., alkali and sulfur-affected) that
reflects soil and bedrock conditions of their watersheds. Upper perennial riverine wetlands
(e.g., in Santa Anita Canyon) generally have rocky beds and shores, occur in montane
settings, and support sparse vegetation characterized by Water Cress (Rorippa nasturium-
aquaticum), rushes such as Iris-leaved Rush (Juncus xiphioides), and other nonpersistent
species. Unconsolidated beds and shores containing sandbars, benches, and shorelines are
more typical of lower perennial and intermittent riverine wetlands.
Lower perennial riverine wetlands occur in some coastal streams with a perennial flow
and can support dense stands of sedges, rushes, cattails, and various forbs that tend to be
more accurately classified as palustrine wetlands if they are persistent enough and
withstand the energy of flowing water. Intermittent riverine wetlands occur in streams
with seasonal flow and generally support nonpersistent weeds, including many non-hydrophytic exotic species.
Because of their extensive and rich riverine wetlands and
adjacent riparian habitats, we consider Cojo, Bulito, Santa Anita, and Agua Caliente
riparian corridors to be among the Ranch's "Representative Botanical Areas of Note"
(Table 2 and Fig. 7).
Palustrine Wetlands. Vegetated palustrine wetlands are dominated by trees, shrubs,
and persistent or nonpersistent emergents, mosses, or lichens, and such wetlands in tidal
areas where salinity from ocean-derived salts in less than
0.5%. At Hollister Ranch, they
include various types of vegetation at habitats such as seeps and springs, water falls, fault
sags, cattle ponds, small reservoirs, and riparian corridors. Eight classes of palustrine
wetlands occur in southern California and most are found at Hollister Ranch. Abiotic-
dominated types include Palustrine Rock-Bottom Wetlands (not observed on the Ranch),
and Palustrine Unconsolidated-Bottom and Unconsolidated-Shore Wetlands such as those
at permanently or seasonally-flooded ponds, which can also be characterized by
nonpersistent emergent plants. Biotic-dominated classes include Palustrine Aquatic-Bed
Wetlands, Palustrine Moss-Lichen Wetlands, Palustrine Emergent Wetlands, Palustrine
Scrub-Shrub Wetlands, and Palustrine Woodland and Forested Wetlands.
Palustrine Aquatic-Bed Wetlands occur in artificial ponds and reservoirs and are
characterized by the rooted-vascular species Fennel-leaved Pondweed (Potamogeton
pectinatus) and Homed Pondweed (Zannichellia palustris). The floating-vascular subclass
is characterized by species of Duckweed (Lemna spp.). Algae-dominated subclasses also
occur in ponds and reservoirs at the Ranch. Palustrine Moss-Lichen Wetlands can occur in
streambeds and at waterfalls.
Palustrine Emergent Wetlands are numerous at Hollister Ranch and occur at seeps and
springs such as those along Del Norte, at waterfalls, in fault-sag wetlands (see Table 2 and
Fig. 7), as persistent forms in streambeds (e.g., Santa Anita and Alegria canyons), along
margins of ponds and reservoirs (e.g., Alegria), and adjacent to intertidal wetlands of
estuaries (e.g., Santa Anita Estuary). The diverse habitats that support Palustrine Emergent
Wetlands are a result of the many contrasts in bed rock, structure, and soils, as well as in
hydrology, water chemistry, and proximity to the coast. The rich vascular flora represented
in these wetlands is a reflection of the Ranch's landscape, as well as its geographic location.
Seeps and springs often support a rich association of sedges, rushes, grasses, and many
forbs, particularly if they are exposed rather than in a dense riparian canopy. Waterfalls
created by differential erosion between the Rincon and Vaqueros formations such as at
Bulito Falls provide permanently wet habitat for Venus Hair Fern (Adiantum capillis-
veneris) and Stream Orchid (Epipactis gigantea). Flooded pond margins (e.g. at Alegria)
often are dominated by aquatic grasses such as Dallis Grass (Paspalum distichum),
whereas seasonally-flooded margins support many hydrophytes and upland pioneer and
weedy species. Rare fault-sag wetlands are generally rush-dominated (e.g., Juncus
phaeocephalms), and are seasonally-flooded or saturated basins that occur in contrast to the
north-south trending canyons, and the east-west trending rock formations. A well-
developed example occurs on the ridge crest in the vicinity of the intersection of Del Norte
and De la Cresta. Palustrine Emergent Wetlands in the vicinity of estuaries are
characterized by salt-tolerant species such as Salt Grass
(Distichlis spicata) and Alkali
Ryegrass (Leymus triticoides).
Palustrine Scrub-Shrub Wetlands on the Ranch generally occur along riparian corridors
and are dominated by deciduous and evergreen subclasses. Along reaches of upper
perennial streams, saturated soils often support stands of Creek Dogwood
(Cornus sericea). Along reaches of intermittent streams, the wetlands typically consist of Arroyo
Willow (Salix lasiolepis), which forms dense thickets with little understory. This riparian
community is found in the lower, flatter reaches of the streams, on clay soils such as occur
with the Rincon Formation. Larger, taller stands of Arroyo Willow also can be classified
as Palustrine Forested Wetland. About 27 acres of "riparian scrub" are found on the Ranch
(Fig. 6), which is less than two-tenths of a percent of the land area. Other shrubs
characteristic of this class include Coyote Brush (Baccharis pilularis), Mule Fat
(Baccharis salicifolia), Elderberry (Sambucus mexicana),
California Rose (Rosa califomica), Blackberry (Rubus ursinus), and Poison Oak
(Toxicodendron diversilobum).
Palustrine Woodland and Forested Wetlands also are generally found along riparian
corridors throughout much of the Ranch. However, they are usually limited to the narrow
stream corridors of canyons and often occur as interrupted stands. Approximately 758
acres occur at Hollister Ranch, or about one-half of one percent of the land area (Fig 6.).
The vegetation is dominated by hydrophytic trees such as Western
Sycamore (Platanus
racemosa), Black Cottonwood (Populus balsamifera ssp. trichocarpa), Arroyo Willow
(Salix lasiolepis), Red Willow (Salix laevigata), Wax Myrtle (Myrica californica), White
Alder (Alnus rhombifolia), and Box Elder (Acer negundo), as well as Coast Live Oak
(Quercus agrifolia) in phreatophytic types with at least seasonally available water tables,
but infrequent or no flooding. Some species, such as White Alder, arc limited to the
moister sites where there is perennial surface water. Understory vegetation is often a dense
thicket of Blackberry, Snowberry, and Poison oak.
A particularly notable form of subclass broadleaved-evergreen is located in the
northwestern portion of the Ranch, and is dominated by Tanbark Oak (Lithocarpus
densiflorus). This wetland includes a small stand of large trees at a spring along the north-
facing slope south of Del Norte (see cover of this report), within a Tanbark Oak Forest
characterized by drier conditions and smaller trees. This type of Palustrine Forested
Wetland has an understory of mosses and Sword Ferns. It is unique in the region, and we
include it as a "Representative Botanical Area of Note" (Table 2, Fig. 7).
Riparian wetland areas are some of the most beautiful plant communities on the Ranch,
in both their architecture and coloration. In spring and summer, a multi-layered filtering
canopy of leaves illuminates tranquil streamsides. Sycamore, Box Elder, and willows turn
yellow and loose their leaves in fall, providing native "fall color". Riparian areas are
important wildlife habitats, providing nesting areas for many birds as well as forage, water,
and cover for other animals. These deserve protection from human impacts where
possible.
BIOGEOGRAPHIC ANALYSIS
One of the most interesting aspects of the Hollister Ranch flora is the biogeographical
diversity unique to this area. The diversity of habitats and the geographical location of the
Ranch produce a rich and varied flora with links to northern and southern California, as
well as to wider geographical areas.
Of the 369 plant taxa native to Hollister Ranch, 70 are defined as cosmopolitan natives,
meaning that they are native to California and to other regions outside of the western states.
An additional 111 are Western, meaning that they are native to the area west of the Rocky
Mountain, and are not confined to the California Floristic Province. The remaining 188
native plants (37.3%) are endemic to the California Floristic Province (as defined in the
Jepson Manual, this includes parts of southern Oregon and northern Baja California). Of
these, 69 are limited to the central and south coast region; 25 are mainly found in areas
north of Point Conception, and 12 are mainly southern in their distribution (south of Pt.
Conception). There are 15 plants that are considered regional endemics, with their main
distribution within coastal Santa Barbara and Ventura counties. Even more limited,
Lompoc Yerba Santa (Eriodictyon capitatum) is known from only a few isolated locations
within northern Santa Barbara county; the Hollister population is the only south coast
location for this state-listed rare plant. Appendix II contains lists the flora with associated
biogeographic and habitat data.
Habitats and regional affinities. The range of microclimatic habitats on the ranch
increases the diversity of its flora. Plants with northern California affinities (including the
regional endemics whose distribution lies mainly in northern SB County) tend to be those
that occupy higher, wetter habitats such as foggy ridgelines and north-facing slopes; for
example the wild lilacs (Ceanothus spp.), manzanitas (Arctostaphylos spp.), Tanbark Oak
(Lithocarpus densiflorus), and Salal (Gaultheria shallon). Southern plants tend to be found
at the lower elevations, on drier slopes with coastal scrub vegetation; these include purple
sage (Salvia leucophylla), California sunflower (Encefia californica), small-leaved cliff
aster (Malacothrix saxatilis var. tenuifolia), and Lemonadeberry (Rhus integrifolia).
A non-native naturalized species typically occupies a range of habitats, unlike most
native plants that tend to be more specialized. An example of the widespread non-native is
Filaree (Erodium cicutarium, from Eurasia), which is found in almost every habitat on the
ranch, from damp shaded forest to dry sandy ridges. From the same family, Geraniaceae,
the native Carolina Geranium (Geranium carolinianum) is limited to relatively moist and
shaded locations or north-facing slopes. Naturalized non-native plants on the ranch tend to
be of Mediterranean or European origin, probably because of historical human
immigration, from those areas as well as the similarity of climate. Exotics from other areas
with Mediterranean-type climates have more recently been very successful in establishing
themselves and are some of our most troublesome weed species. These include Veldt Grass
(Ehrharta calycina, S. Afr.), Kikuyu Grass (Pennisetum clandestinum, S. Afr.), Blue Gum
(Eucalyptus globulus, Aust.), Hottentot Fig (Carpobrotus edulis, S. Afr.), Pepperberry
Tree (Schinus molle, Chile), and others.
Cosmopolitan natives are species whose natural distribution includes areas outside the
western states, and in some cases are found almost worldwide. Interestingly, most of the
cosmopolitan natives are typically plants of wetland or riparian habitats; for example, there
are five bulrushes (Scirpus spp.) on the ranch, all of which are cosmopolitan; the cattails
(Typha spp.) are all in this group, as are many of the other plants that are typical of
wetlands and streams on the ranch (Appendix 11).
Table 2. Hollister Ranch: Representative Botanical Areas of Note. Refer to Figure 7 for
location of representative areas. Species are organized alphabetically.
Areas of Note for Plant Species
1. Acer negundo var. califomicum, Box Elder (e.g., Parcel 7; rare on HR)
2. Antirrhinum nuuallianum ssp. subsessile Nuttall's Snapdragon (e.g., Parcel 94; Species of Special Interest)
3. Arbutus menziesii, Madrone (e.g., Parcel 61; rare on HR)
4. Brodiaea jolonensis, Brodiaea (e.g., Parcels 1 15, 116, 117; uncommon on HR and South Coast)
5. Calochoilus catalinae, Catalina Mariposa Lily (e.g., Parcel 129; large population; Species of Special Interest)
6. Calochortus weedi var. vestus, Weed's Mariposa Lily (e.g., Parcel 81; Species of Special Interest)
7. Calystegia nzacrostegia var. macrostegia (e.g., Parcels 70,104; Channel Islands endemic except for HR)
8. Castilleja affinis, Indian Paintbrush (e.g., Parcel 81; yellow-flowered form rare; similar to
Santa Cruz Island plants)
9. Castilleja exerts ssp. exerts, Purple Owl's Clover (yellow-flowered form uncommon on South Coast)
1O. Ceanothus papillosus var. papillosus, Warty-Leaved Ceanothus (Parcel 45; Species of Special Interest)
11. Comarostaphylis diversifolia ssp. planifolia, Summer Holly (Species of Special Interest)
12. Coreopsis gigantea, Giant Coreopsis (between Alegria and Agua Caliente canyons; rare on HR)
13. Cornus sericea, Creek Dogwood (e.g., Parcel 61; uncommon on HR; generally restricted to perennial streams)
14. Deschampsia danthonioides, Annual Hairgrass (e.g., Parcels 63, 104; rare on HR; Species of Special Interest)
15. Epipactisgigantea, Stream Orchid (Bulito Falls; rare on HR)
16. Erigeron sanctarum, Saint's Daisy (e.g., Parcel 43; Species of Special Interest)
17. Eriodictyon capitatum, Lompoc Yerba Santa (e.g., Parcels 1, 21, 22, 43, 45, 46; regional endemic; Species of
Special Interest)
18. Fritillaria biflora, Chocolate Lily (e.g., extensive colonies on Parcels 46, 81)
19. Gaultheria shallon, Sala (e.g., Parcels 4, 81; southern limit; Species of Special Interest)
20. Hemizonia increscens ssp. increscens, Tarweed (e.g., Parcel 98; perhaps similar ssp. villosa, an endangered
regional endemic at nearby Gaviota)
2 1. Heuchera pilosissima, Alum Root (Parcel 46; rare on HR; Species of Special Interest)
22. Horkelia cuneata ssp. sericea, Kellogg's Horkelia (e.g., Parcels 96, 113; Species of Special Interest)
23. Lilium humboldtii ssp. ocellatum, Humboldt Lily (Species of Special Interest)
24. Malacothrix saxatilis var. saxatilis, Cliff Aster (regional endemic; Species of Special Interest)
25. Monardella hypoleuca, Penny Royal (e.g., Parcel 81; rare on HR)
26.Orobanche californica ssp. grandis,
Large-flowered Broomrape (e.g.,ParceII17;SpeciesofSpeciallnterest)
27. Phacelia cicutaria var. hubbyi, Caterpillar Phacelia (e.g., Parcel 9; uncommon on HR)
28. Piperia elegans, Rein Orchid (e.g., Parcels 46, 47; rare on RR)
29. Potanwgeton foliosus, Leafy Pondweed (rare on HR; generally in perennial streams)
30. Quercusparvula var.parvula, Santa Cruz Island Oak (e.g., Parcels 43,46; regional endemic;
Species of Special Interest)
31. Quercus parvula X Q. kelloggii, Oracle Oak (Parcel 1; rare hybrid oak)
32. Rubus parviflorus, Thimbleberry (Parcel 46; rare on HR; Species of Special Interest)
33. Solanum xanti var. hoffmannii, Hoffmann's Nightshade (e.g., Parcel 70; regional endemic;
Species of Special Interest)
34. Trillium angustipetalum, Wake Robin (Parcel 46; rare on HR; Species of Special Interest)
35. Vicia gigantea, Giant Vetch (e.g., Parcel 61; rare on HR and southern limit; Species of Special Interest)
Sites of Note for Vegetation or Habitat
Wetlands:
36. Marine Aquatic-Bed Rooted-Vascular Wetland (characterized by Phyllospadix torreyi, Surf Grass; e.g., Parcels
49, 70, 104, and Alegria Preserve)
37. Estuarine Aquatic-Bed Rooted-Vascular Wetland (e.g., Parcel 104, Santa Anita Estuary; characterized by Ruppia
cirrhosa, Ditch Grass; estuary also supports a population of Tidewater Gobi, an endangered fish)
38. Riverine Wetlands, perennial streamflow (e.g. Bulito Canyon and Bulito Falls)
39. Palustrine Emergent Wetland (e.g., a fault sag wetland)
40. Palustrine Scrub-Shrub Wetland (e.g., Bulito Canyon)
41. Palustrine Forested Broadleaved Evergreen Wetland (dominated by Lithocarpus densiflorus, Tanbark Oak)
Uplands:
42. Native Perennial Grasslands (e.g., Parcels 49, 81, 104, characterized by Hordeum californicum, California
Barley, and/or Nassella pulchra, Purple Needlegrass)
43. Coastal Sage Scrub (locally unique sand substrate type with rich native flora)
44. Maritime Chaparral (examples rich in species and with various regional endemic shrubs)
45. Coast Live Oak Forest (Bulito Canyon is most extensive example)
46. Tanbark Oak Forest
Corridors:
47. Riparian Corridors, including upland and wetland habitats, such as Riverine Wetlands and Palustrine
Scrub-Shrub and Forested Wetlands (e.g., Cojo, Bulito, San Anita, and Agua Caliente canyons)