15

Chapter 2

Chapter 2 – Mountain and Foothills

Ecosystems

Key Questions

• What are the major ecological

communities in the coastal

mountains of southern California?

• What is known about the status and

distribution of each?

• How have they changed in the last

100 to 200 years?

• What rare communities exist and

what are their status and trends?

This chapter provides a large-scale overview of landscape patterns and ecological

communities within the assessment area. A

more detailed description of the specific ecological processes and human land uses affecting

these ecosystems is presented in chapter 3.

Here we focus on the extent and distribution

of each type, its current condition, and its representation on public lands across the different

mountain ranges. Much of this information

is based on our GIS vegetation data. However, first we describe the coarse-filter analysis

approach that is a major component of this

assessment.

The Coarse-Filter, HabitatBased Approach

According to the California Wildlife Habitat Relationships System (CWHR, version

5.2) and the California Flora Database

(CALFLORA), the mountains and foothills

of southern California are inhabited by 18

amphibian, 61 reptile, 299 bird, 104 mammal, and 2,900 vascular plants species (CDFG

1996; Dennis 1995). Added to that is an unknown multitude of invertebrate animals and

nonvascular plants. We know very little about

the specific habitat needs of the majority of

these species. So how do we address all of this

biological diversity in a feasible manner?

Until recently, wildlife management

tended to focus on the needs of a few, highprofile species (mostly game animals and

endangered species). Now the potential importance of all members of an ecosystem has

been recognized and the focus has shifted away

from single-species management and towards

ecosystem-based conservation (Hansen et al.

1993; Manley et al. 1995; Haufler et al. 1996).

The idea that conserving broad ecological

communities may be the most efficient way

to maintain species diversity has gained widespread acceptance and is implicit in the

so-called coarse-filter approach (Noss 1987).

Originally developed by The Nature Conservancy, the coarse-filter approach assumes that

a representative array of ecological communities

will sustain the vast majority of species, including many of the ones we know little about (fig

2.1)(Hunter et al. 1988). By relying on retention of community types and providing an array

of structures and compositions, we hope to “capture” most of the diversity in the system.

However, we know that some species, subspecies, and rare communities have characteristics

that make them “fall through the mesh” of the

coarse filter and these need special attention (i.e.,

a finer filter). The fine-filter approach focuses

on learning the specific needs of individual species and then providing for those needs,

potentially through intensive management.

To understand the fashion of any life, one must know the land it is

lived in and the procession of the year.

 — Mary Austin (1903)
16

In this assessment we employed a combined coarse-filter/fine-filter approach.

Fine-filter criteria were used to identify species that would receive individual

consideration (fig 2.2). The criteria primarily

target species that are rare and vulnerable.

However, we also identified species that have

a heightened status due to the high public interest that they generate. Thus, the fine-filter

list is really divided into two distinct categories: (1) species potentially at risk and (2)

species of high public interest. Each species

identified in the fine-filter list does not necesSpecies Potentially at Risk:

• A Threatened, Endangered, or Proposed

Species (federal and state)

• A former USFWS Candidate (C1 or C2) Species

• A Forest Service, Region 5 Sensitive Species

• A California Species of Special Concern

• A Riparian Obligate Species of Concern (as

defined by California Partners in Flight)

• A species determined to have viability concerns

at a local level

Species of High Public Interest:

• A major game animal

• A species that has particular public interest (e.g.,

mountain lion)

Based on the fine-filter screening criteria,

184 animals and 256 plants made the focal

species list. These species are addressed in

chapters 4 and 5, “Species at Risk,” and chapter 6, “Species of High Public Interest.” All

other plants and animals occurring within the

assessment area will only be addressed indirectly, via the coarse-filter, community-level

analysis.

The coarse-filter analysis procedure is

quite simple: Current conditions are compared

to reference conditions (based on how the

landscape would look and function if people

were not altering it), differences between the

two are identified, the significance of the

change is analyzed, and this information is fed

into the decision-making process. However,

the application of these ideas can be quite complicated (Sampson et al. 1997).

The reference conditions represent our

best attempt to describe the ecological conditions, including their variability over space and

time, under which native species evolved. If

sarily require specific management attention.

Rather, it suggests that their status and needs

warrant individual consideration before deciding on a course of action.

Figure 2.1. The coarse-filter approach to

maintaining biological diversity focuses on

protecting a representative array of communities

and is based on the assumption that these

communities will encompass the vast majority of

species. The fine-filter approach focuses on saving

individual species that slip through the coarse filter.

As illustrated here, the coarse filter has been used

to save a tract of Zaire’s forest, while the fine-filter

approach has been employed for the pygmy

chimpanzee and Congo peafowl (from Hunter et al.

1988).

Figure 2.2. Fine-filter criteria used to identify

species that should receive individual consideration

in this assessment. A species or subspecies made

the list if it met one or more of the criteria.
17

Chapter 2

today’s conditions are similar to the reference

conditions, we are confident that adequate habitat is present for most species. The greater the

deviation from the reference conditions, the more

species may be at risk. (Sampson et al. 1997).

An inherent difficulty with this approach

is that it is usually difficult to determine the

“true” reference conditions and the natural

range of variability. They must be inferred

based on our knowledge of historic habitat

conditions and on our understanding of key

ecological processes such as fire, succession,

and flooding. Since the historic record is frequently sketchy and inconclusive, there are

usually several plausible theories on how the

historic landscape might have looked and

functioned.

These problems are compounded by the

fact that we will often be managing outside

the range of conditions that native species

encountered in the past. In some places, the

ecological systems are so altered that we will

typically be outside the range of conditions

that occurred historically (e.g., in dammed

river systems or in grasslands that are now

dominated by non-native species). Social considerations (e.g., reducing fire hazards near

towns) and economic factors also affect our

ability to remain in (or move toward) more

“natural” landscapes. The farther we move

from those conditions, the less successful we

can expect the coarse-filter approach to be

(Sampson et al. 1997).

Despite these difficulties, the coarse filter

can be an effective approach for (1) retaining

biological diversity in its broadest sense, (2)

retaining critical but little understood processes (such as roles played by soil microbes),

and (3) sustaining species that we currently

know little about.

Broad-Scale Landscape

Mosaics

From an airplane, land usually appears as

a mosaic of patches, corridors, and matrix

(Forman 1995). Woodlands, fields, and housing tracts often stand out as conspicuous

patches. Rivers form equally striking corridors.

In between the patches and corridors is the

surrounding matrix — a dominant vegetation

or land type, such as chaparral in the foothills

or urbanized land in the Los Angeles Basin.

Across the southern California mountains

and foothills region there are a few broad-scale

landscape mosaics that are clearly recognizable

and repeatedly encountered. In the coastal

foothills the matrix is coastal scrub and chaparral interspersed with riparian corridors, oak

woodlands, and grasslands. Above the foothills on often-steep lower mountain slopes, the

mosaic shifts to patches of mixed hardwood/

conifer forest scattered between large expanses

of chaparral. As you move into the upper

mountain region, pine and fir forests dominate the landscape and are punctuated with

patches of black oak woodland, montane

meadows, and chaparral. On the desert side

of the mountain crest is another distinct landscape, dominated by sparse pinyon forests,

juniper woodlands, desert scrub, and extensive areas of bare rock.

Key physical factors that seem to trigger

broad-scale changes in the vegetation mosaic

are elevation, distance from the coast, topography, and position on either the coastal or

desert side of the mountain crest. These factors have a strong influence on precipitation

amounts and temperature regimes, which in

turn greatly influence the type of vegetation

that grows. Today, human land use also plays

a key role in shaping these land mosaics.

Below we describe and present a map (fig.

2.3) of the six large-scale vegetation mosaics

that characterize the mountains and foothills

of southern California. In reality these mosaics, or “landscapes” as we refer to them here,

do not have distinct boundaries but rather have

broad transition zones where different vegetation assemblages intergrade. However, each

landscape has unifying characteristics that have

important implications for resource management. These characteristics transcend the

particulars of which mountain range or watershed the landscape may be found in. There

are clear differences in the way each landscape

type has historically been affected and shaped
18

Coastal Foothills Landscape

The foothills range from approximately

800 to 3,000 feet in elevation on the coastal

side of the mountains. In San Diego County,

foothill vegetation patterns extend up to 4,000

feet in some places. Although topographically

varied, the foothills are distinguished by many

miles of relatively gentle hilly terrain. Rolling

hills, plateaus, and broad valleys are common.

Chaparral is the most common vegetation, but

the foothills are also characterized by oak savannas and woodlands (fig. 2.4), coastal sage

scrub, and corridors of riparian hardwood forFigure 2.4. Looking south from Palomar Mountain, Cleveland National Forest, you see a typical foothill

landscape: oak woodlands and savannas surrounded by chaparral-covered hills. CNF FILE PHOTO

by fire, human habitation (both Native American and early European), and other natural

processes. There are also differences in the way

each landscape has been affected by recent

activities, such as the last eighty to one hundred years of active fire suppression and rapid

human population growth. Because of the

unique vegetation patterns in each landscape

there are also clear distinctions in the land use

activities that take place today in each of them.

est (table 2.1). Oak woodlands and savannas

become increasingly abundant in the foothills

as you move north. This landscape is most extensive in the Coast Ranges (southern Santa

Lucia Range, southern Los Padres region), and

the southern Peninsular Ranges (Santa Ana

Mountains, San Diego region).

Table 2.1. The mix of dominant vegetation types

in the foothills landscape.

Chaparral 1,407,079 55%

Grassland/

 oak savanna 351,930 14%

Coastal scrub 323,250 13%

Oak woodland 268,542 11%

Development/

 agriculture 112,099 4%

Other 81,890 3%

Total: 2,544,790

Vegetation Type Acres % of Foothills
19

Chapter 2

Figure 2.5. The Agua Tibia Wilderness, Cleveland National Forest, is a typical lower montane landscape.

Dense patches of bigcone Douglas-fir occupy steep canyons surrounded by chaparral. CNF FILE PHOTO

Lower Montane Landscape

The lower montane landscape encompasses mountain slopes from approximately

3,000 to 5,000 feet elevation on the coastal

side of the ranges. This mosaic is characterized by frequently steep and rugged

topography. Chaparral dominates the hillsides

but is interspersed with patches of forest, primarily in canyons and on north-facing slopes

(table 2.2). Forest types are typically a conifer/hardwood mix. The most prevalent

conifers are bigcone Douglas-fir, Coulter pine

(fig 2.5), and incense-cedar, all of which occur primarily in mixed stands with canyon or

coast live oak. Stands of black oak also occur,

particularly at the upper elevations. Most of

the conifer trees in this landscape are endemic

to southern California and northern Baja (i.e.,

Coulter pine, bigcone Douglas-fir, Tecate cypress, Cuyamaca cypress and Sargent cypress).

Chaparral

 or scrub 1,181,995 72%

Bigcone Douglas-fir/

 Coulter pine/

 canyon oak 272,649 17%

Oak woodland 102,979 6%

Grassland/savanna 35,159 2%

Mixed conifer 28,966 2%

Other 25,560 2%

Total: 1,647,308

Table 2.2. The mix of dominant vegetation types in

the lower montane landscape.

Vegetation Type Acres % of Lower

Montane
20

Figure 2.6. This view from Brush Mountain looking towards Mount Abel, Los Padres National Forest,

shows several types of montane conifer forest. The open Jeffrey pine stand on Brush Mountain is

typical of arid, high-country forests on the desert side of the mountains. The dense forest blanketing

the north slope of Mount Abel is typical of upper elevation mixed conifer. J.D. BITTNER

Vegetation Type Acres % of Montane

Conifer

Montane Conifer Landscape

The montane conifer landscape (fig. 2.6)

extends from approximately 5,000 to 8,500

feet in elevation and is dominated by pine and

fir forests (table 2.3). Stands of black oak are

also interspersed. In some areas near the lower

elevational limit, oaks are as abundant as conifers. As the elevation rises, dominance in the

conifer overstory shifts from ponderosa pine

to Jeffrey pine to white fir. Black oak declines

in abundance as elevation increases and as you

move from the coastal side to the desert side

of the mountains. Sugar pine and incense-cedar are secondary components in many stands.

Montane meadows and chaparral are also interspersed. Towards the desert side of the

mountains, western juniper becomes a component of pine and mixed conifer stands all

the way up to 8,500 feet.

Table 2.3. The mix of dominant vegetation types

in the montane conifer landscape.

Pine or fir forest 379,304 76%

Montane chaparral 77,338 16%

Oak woodland 20,919 4%

Meadows/sagebrush 15,434 3%

Other 6,121 1%

Total: 499,116
21

Chapter 2

Figure 2.7. This view to the northeast of Baldwin Lake, San Bernardino National Forest, shows pinyon

pine woodlands and sagebrush flats that are characteristic of the desert-side montane landscape. LYNN

LOZIER

Desert Montane Landscape

The desert montane landscape covers a

wide elevation range (approximately 3,000 to

7,000 feet) but is often a narrow transition

zone between the mountains and the desert.

Pinyon pine and juniper woodlands (fig. 2.7),

scrub oak chaparral (e.g., Tucker oak), red

shank chaparral, and desert scrub are the predominant vegetation types (table 2.4). In this

arid landscape, plant communities generally

provide sparse cover with a lot of bare ground

in between. This mosaic is most extensive in

the lower elevations surrounding Mount

Pinos, along the northern slopes of the San

Gabriel and San Bernardino mountains, and

along the eastern slopes of the San Jacinto

Mountains.

Vegetation Type Acres % of Desert

 Montane

Table 2.4. The mix of dominant vegetation types in

the desert montane landscape.

Pinyon or

 juniper woodland 346,594 36%

Semi-desert

 chaparral/scrub 219,658 23%

Mixed and red shank

 chaparral 130,391 14%

Buckwheat, grass,

 barren 122,926 13%

Conifer or oak forest 29,904 3%

Other 27,709 3%

Total: 955,592
22

Figure 2.8. Sparse stands of limber pine on the

upper slopes of Mount Baden-Powell, Angeles

National Forest, are characteristic of subalpine

forests near timberline. ANF FILE PHOTO

Table 2.6. The mix of dominant vegetation types in

the Monterey coast landscape.

Vegetation Type Acres % of Monterey

Coast

Subalpine/Alpine Landscape

The subalpine/alpine landscape occurs at

elevations above 8,500 feet. It covers a very

small portion of the southern California

mountains found only on the summit of

Mount Pinos and in the highest reaches of

the San Gabriel, San Bernardino, and San

Jacinto ranges. Subalpine and alpine habitats

are most extensive on the high slopes of

Mount San Gorgonio and Mount San Jacinto

(fig. 2.8). The primary plant community is

subalpine forest (table 2.5) that consists of

white fir, lodgepole pine, and limber pine.

These are often relatively sparse forests characterized by small diameter trees. A rare and

fragile alpine cushion plant community occurs above treeline.

Monterey Coast Landscape

The Monterey coast landscape (fig. 2.9)

occurs only along the coastal slopes of the

northern Santa Lucia Range. It is characterized by the southernmost occurrence of coastal

redwood forest, and the southernmost concentrations of Douglas-fir and Pacific

madrone (table 2.6). Santa Lucia fir is also

endemic to this region. These are low-elevation (sea level to 4,500 feet), mesic forests

similar in composition and structure to forests along the northern California coast. They

are distinctly different from the montane conifer forests found at higher elevations in the

rest of the assessment area.

Chaparral/scrub 35,264 35%

Redwood/

 conifer forest 32,369 32%

Oak or bay forest 25,466 25%

Grassland/

 savanna 6,751 7%

Other 22 <1%

Total: 99,872

Vegetation Type Acres % of

Subalpine

Table 2.5. The mix of dominant vegetation types

in the subalpine/alpine landscape.

Subalpine conifer

 forest 8,229 53%

Mixed conifer–fir 2,504 16%

Montane chaparral/

 scrub 2,890 19%

Alpine or barren 1,913 12%

Other 68 0%

Total: 15,604
23

Chapter 2

Figure 2.9. The northern Santa Lucia Range rises dramatically above terraces along the Monterey

coast. The coastal slopes of these mountains support the southernmost stands of coast redwood

forest. JEFF KWASNY

Foothill Oak Woodlands

Foothill woodlands tend to occur in two

distinct forms: as closed-canopy stands in canyons or along streams, and as open savannas

in broad valleys and rolling hills. Closedcanopy stands have a dense overstory of trees

with little space between the crowns (fig.

2.10). Coast live oak is usually the dominant

tree in these dense woodlands. Closed-canopy

coast live oak woodlands are widely distributed in the foothills and better represented

on public lands than the open savanna woodlands (table 2.8).

Savanna woodlands are characterized by

widely scattered trees with grass or coastal

scrub in between (fig. 2.11). These savannas

contain coast live oak but are more typified

by blue or valley oak in the north and Engelmann oak in the south. Savanna woodland

types are less extensive and more concentrated

on private lands (table 2.8). Engelmann oak,

valley oak, and California walnut woodlands

are considered rare communities in our assessment area because of limited distribution and

poor representation on public lands (Scott

1990).

Major Ecological

Communities

Many different vegetation types occur

along the southern and central California coast

(table 2.7). Most of these extend into the

mountains and foothills to some degree. In

this section, we describe the distribution, characteristics, and status of the dominant

vegetation communities.

Livestock production has long been the

principal economic activity in foothill woodlands (Pavlik et al. 1991). Most of the private

land is consolidated in ranches that vary in

size from less than a hundred to many thousands of acres. Grazing allotments have been

in place for many years on national forest system lands and are particularly common in oak

savanna types. On national forest system lands,

60 percent of Engelmann oak woodlands and
Table 2.7. The vegetation types occurring along the southern and central California coast and associated

series-level plant communities as described and numbered in Sawyer and Keeler-Wolf (1995). The

primary types are crosswalked from CWHR and CALVEG calssifications.

Hardwood Forests and Woodlands

Valley–foothill woodlands

From sea-level to ~3,600 ft.

Oak woodland

Usually open, savanna-like woodlands with grass

below. Or along streams or north slopes.

Blue oak 230

Coast live oak 241

Engelmann oak 253

Valley oak 312

Walnut woodland

California walnut 238

Valley–foothill riparian

From sea-level to ~4,500 ft. in canyons and flood plains.

Stands usually denser than upland woodlands, but narrow.

Riparian forest

Black cottonwood 226

Black willow 229

California bay 234

California sycamore 237

Coast live oak 241

Fremont cottonwood 259

Mixed oak 277

Red willow 299

Red alder (north central coast only) 295

White alder 319

Riparian scrub

Arroyo willow 219

Buttonbush 119

Mexican elderberry 171

Mixed willow 279

Mulefat 179

Narrowleaf willow 180

Pacific willow 287

Sitka willow 307

Tamarisk 203

Montane upland hardwoods

From ~3,000-8,000 ft. Occur in pure stands, but more often

associated with conifers. Upland live oak stands often consist

of low, shrubby trees.

Black oak 227

California buckeye 235

Canyon live oak 239

Interior live oak 264

Mixed oak 277

Montane riparian hardwoods

From ~3,600-8,000 ft. In canyons and along streams. Riparian

live oak stands consist of tall trees with spreading crowns.

Aspen (1 grove, San Bernardino Mts) 220

California bay 234

Canyon live oak 239

Interior live oak 264

White alder 319

Conifer and Conifer/ Hardwood Forests

North Central Coast Range forests

These occur only in the northern portion of the Central Coast

Ecoregion, including the Monterey District of Los Padres NF.

Douglas-fir 246

Douglas-fir/ponderosa pine 249

Douglas-fir/tan oak 250

Redwood 300

Santa Lucia fir 302

Cypress and coastal pine

From sea-level to 5,500 ft. Uncommon, localized habitats.

Cypress forest

Cuyamaca cypress 333

Gowen cypress 337

Monterey cypress 340

Sargent cypress 303

Tecate cypress 345

Coastal pine forest

Bishop pine 225

Monterey pine 280

Torrey pine 346

Lower montane conifer/hardwood

From ~3,000 to 5,500 ft. Stands frequently patchy and

surrounded by chaparral. They intermix with montane conifer

at upper elevations. Live oak understory is common.

Foothill pine/oak forest

Usually open stands, conifers even-aged, shrubs or

grass below.

Coulter pine 243

Coulter pine/canyon live oak 244

Foothill pine (grey, foothill,digger) 257

Knobcone pine 269

Bigcone Douglas-fir forest

Usually dense, multi-layered stands on steep slopes in

canyons.

Bigcone Douglas-fir 222

Bigcone Douglas-fir/canyon live oak 223

Montane conifer

From ~5,000 to 8,500 ft.

Mixed conifer – pine/oak phase

Jeffrey/ponderosa/sugar pines, live oak, black oak and

incense cedar. White fir present, but seldom dominant.

Oaks common in most of this type and are the dominant

stand component in some areas (e.g. the southern

Peninsular ranges).

Jeffrey pine/ponderosa pine 268

Incense-cedar 263

Mixed conifer 275

Jeffrey pine

Open Jeffrey pine stands with few associated species.

Black oak, white fir and western juniper can be present.

In cold, dry, high-elevation sites. Mostly eastern slopes.

Jeffrey pine 266

Mixed conifer – white fir phase

White fir codominate with sugar and Jeffrey pine. Black

oak or live oak common in some stands. Occurs in

mesic, high-elevation sites.

Mixed conifer 275

White fir 321

Subalpine conifer forests

From 8,500 to >10,000 ft.

Limber pine 270

Lodgepole pine 271

Mixed subalpine forest 278

Pinyon/juniper woodlands

From ~3,000 to 8,500 ft. on arid desert-facing slopes.

California juniper 236

Mountain juniper 283

Parry pinyon (four needle) 288

Singleleaf pinyon 304

Western juniper 316

Vegetation types

 Series

(from Sawyer & Keeler-Wolf 1995)
Shrublands and Chaparral

Coastal scrub

From sea-level to ~3,600 ft. “Soft chaparral.” Shrubs not very

woody and stands more open than in chaparral types.

Black sage 109

California buckwheat 120

California buckwheat/white sage 122

California encelia 123

California sagebrush 124

Calif. sagebrush/black sage 126

Calif. sagebrush/Calif. buckwheat 127

Coast prickly-pear 141

Coyote brush 142

Mixed sage 172

Purple sage 184

Salal-black huckleberry 191

Scalebroom 193

Chaparral

From sea-level to 5,000 ft. Woody shrubs in stands that

usually become very dense when mature (>10 yrs old).

Coastal maritime chaparral

Chamise/black sage 133

Leather oak 169

Woollyleaf manzanita 211

Sumac 202

Chamise chaparral

Chamise 130

Chamise/black sage 133

Chamise/white sage 139

Southern mixed chaparral

Chamise/mission manzanita/

 Woollyleaf ceanothus 137

Northern mixed chaparral

Bigberry manzanita 102

Bigpod ceanothus 103

Bigpod ceanothus–

 birchleaf mt. mahogany 104

Bigpod ceanothus–hollyleaf redberry 105

Birchleaf mt mahogany/CA buckwheat 106

Blue blossom 112

Chamise/bigberry manzanita 132

Chamise/cupleaf ceanothus 134

Chamise/eastwood manzanita 135

Chamise/hoaryleaf ceanothus 136

Chamise/wedgeleaf ceanothus 138

Eastwood manzanita 151

Chaparral whitethorn 140

Hoaryleaf ceanothus 157

Wedgeleaf ceanothus 206

Holly leaf cherry 339

Redshank chaparral

Redshank 185

Redshank–birchlf. mt. mahogany 186

Redshank–chamise 187

Scrub oak chaparral

Scrub oak 194

Scrub oak–birchleaf mt. mahogany 196

Scrub oak–chamise 197

Scrub oak–whitethorn 198

Mixed scrub oak 174

Montane chaparral

From 4,000 to 10,000 ft. Characterized by absence of chamise

and presence of species found only in the mountains. Usually

dense and woody.

Bush chinquapin 117

Canyon live oak shrub 128

Deerbrush 148

Greenleaf manzanita 155

Mountain whitethorn 178

Huckleberry oak 160

Tobacco brush 205

Live oak scrub

Int. live oak scrub 161

Int. live oak/cyn. live oak scrub 163

Int. live oak/whitethorn scrub 164

Int. live oak-scrub oak scrub 165

Interior/desert scrub

From ~3,000 to 7,000 feet on desert-side of the mountains.

These shrublands are generally sparser than those on coastal

slopes.

Big sagebrush 100

Black bush 108

Black sagebrush (Big Bear pebble plains) 110

Bladderpod-CA ephedra-

 narrowleaf goldenbush 111

Brittlebush 114

CA buckwheat-white sage 122

Creosote bush 144

Creosote bush-white bursage 145

Cupleaf ceanothus/fremontia/oak 146

Fourwing saltbush 153

Joshua tree 168

Mohave yucca 175

Nolina 181

Rubber rabbitbrush 189

Scrub oak 194

Shadscale 199

White sage 208

Grasslands, Meadows & Herbaceous Types

Grasslands

Alkali sacaton 30

Creeping ryegrass 47

Desert needlegrass 50

Foothill needlegrass 55

Nodding needlegrass 67

California annual grassland 40

One-sided bluegrass 68

Purple needlegrass 75

North central coastal prairie

Cal. oat grass 42

Idaho fescue 59

Introduced perennial grassland 61

Pacific reedgrass 69

Tufted hairgrass 88

Meadows

Alkali sacaton 30

Montane meadow 353

Nebraska sedge 65

Sedge, shorthair sedge 82,85

Subalpine meadow 356

Alpine

Alpine habitat 349

Sedge 82

Subalpine upland scrub 357

Seeps/bogs/marsh/vernal pools

Bulrush, bulrush-cattail 35, 37

Bur-reed 39

Cattail 43

Ditch-grass 52

Duckweed 53

Montane wetland scrub 355

Mosquito fern 63

Pondweeds 73, 74

Quillwort 76

Saltgrass 78

Spikerush 86

Subalpine wetland shrub 358

Vernal pools

Montane vernal pools (not in Sawyer)

San Diego Mesa vernal pools 369

San Jacinto Valley vernal pools 370

Santa Rosa Plateau vernal pools 371
26

Other factors affecting ecosystem condition in foothill savanna woodlands include the

spread of non-native species (particularly

Mediterranean annual grasses) and oak regeneration problems. Introduced annual grasses

grow rapidly during spring and deplete surface water much earlier in the season than the

displaced native perennial grasses (Pavlik et al.

1991). This diminishes water supplies to oak

seedlings. Blue, valley, and Engelmann oak are

not regenerating well in many savanna woodlands (Holland 1976; Scott 1990). This does

not appear to be the result of one single factor

but rather the combined effect of non-native

grasses, grazing, and an unnatural abundance

of acorn-eating animals such as gophers and

ground squirrels (Borchert et al. 1989;

Schoenherr 1992).

The closed-canopy coast live oak woodlands are less threatened. Regeneration does

not appear to be a problem and coast live oak

is a vigorous crown sprouter after fires.

Cismontane Scrub and Chaparral

Coastal scrub and chaparral are the dominant ecological communities on the coastal

side of the mountains below 5,000 feet.

Coastal sage scrub occurs primarily at elevations below 2,500 feet and is most widespread

in coastal valleys and plains west of the foothills. Chaparral occurs across a broad

elevational range but is particularly abundant

in lower montane and foothill areas.

Coastal sage scrub consists of droughtdeciduous, soft-leaved shrubs, frequently

dominated by California sagebrush, buckwheat, and several sage species (fig 2.12)

(Mooney 1977). The extent of coastal sage

scrub has been greatly reduced by conversion

to agricultural, industrial, and residential land

Figure 2.11. This blue oak stand on the Los Padres

National Forest is characteristic of the oak savannas

and woodlands found in broad valleys, rolling hills

and mesa tops. MARK BORCHERT

87 percent of blue oak woodlands are within

grazing allotments.

Over the past twenty years, an increasing

number of large foothill ranches have been

subdivided and converted into ranchette-style

housing developments. This trend is expected

to continue and perhaps intensify in the coming decade, particularly in the southern

counties where demand is greatest (i.e., San

Diego, Riverside, Ventura, and Santa Barbara

counties).

The trend towards increased development

of foothill woodlands has several clear implications for public land management. As the

urban interface expands and increasingly surrounds public wildlands, demand for

recreation and other facilities increase and the

Figure 2.10. This coast live oak stand in the San

Mateo Wilderness, Cleveland National Forest, is

characteristic of dense foothill woodlands frequently

found in canyons and along streams. ANNE FEGE

ability to manage fire on the landscape becomes more constrained. Second, the decline

of high-quality oak woodlands on private lands

increases the significance of such habitats on

public lands. Finally, the decline of ranching

in this region, particularly in the southern

counties, is gradually reducing the amount of

livestock grazing on public land.
27

Chapter 2

Figure 2.12. Coastal sage scrub, like this area in

Riverside County, is dominated by soft-leaved

shrubs. JAN BEYERS

use (Davis et al. 1994; O’Leary 1990). It is

now found in only about 15 percent of its

former range in southern California (Westman

1981; O’Leary 1990). The remnant stands of

coastal sage scrub are habitat for a growing

number of endangered taxa such as the California gnatcatcher (Davis et al. 1994).

Table 2.8. Acres of foothill oak woodland by mountain range. Values in parentheses are the percentage of

those acres occurring on public lands. These figures represent land area where the specified vegetation type

is dominant. They are derived from a large-scale GIS vegetation layer that combines data from several

different mapping efforts (see “Information Sources” section, chapter 1.)

Cleveland NF Los Padres NF San Bernardino NF Angeles NF

San

Diego

 Ranges

Santa

Ana

Mts

San

Jacinto

Mts

San

Bernardino Mts

San

Gabriel

Mts

Castaic

Ranges

S. Los

Padres

Ranges

S. Santa

Lucia

Rng

N. Santa

Lucia

Rng TOTAL

Acres of Foothill

Woodland

Vegetation Types

Blue oak woodland 1,483

(22%)

31,487

(45%)

88,409

(33%)

9,104

(63%)

130,483

(38%)

Engelmann oak woodland 4,029

(45%)

21,083

(12%)

17,054

(5%)

Valley oak woodland 410

(3%)

388

(8%)

7,699

(8%)

8,497

(8%)

CA walnut woodland 30

(100%)

3,896 3,926

(1%)

Alvord oak woodland 1,617

(4%)

1,617

(4%)

TOTAL 14,210

(53%)

2,313

(52%)

18 11,207

(66%)

6,071

(48%)

121,844

(48%)

184,492

(31%)

87,697

(84%)

489,082

(45%)

61,297

(23%)

Coast live oak woodland 10,181

(56%)

2,153

(52%)

18 11,177

(66%)

4,178

(62%)

86,073

(51%)

88,384

(30%)

76,976

(89%)

323,476

(52%)

44,243

(30%)

However, our assessment area encompasses

only the upper elevational limits of coastal

scrub where some of the associated rare species, including the gnatcatcher, are less

abundant or absent.

Chaparral consists of evergreen, woody

shrubs (e.g., chamise, manzanita and

ceanothus) (fig. 2.14). There are many types

of chaparral (table 2.7) and they vary widely

in species composition (Gordon and White

1994). In general, chaparral is abundant in the

A major factor affecting ecosystem health

in coastal sage scrub is fire frequency. This type

of vegetation burns easily and is capable of

reburning only one or two years after a previous fire. Frequent reburns result in the

conversion of these shrublands to annual, nonnative grasslands (Zedler et al. 1983) (fig 2.13).

Since this ecosystem is increasingly adjacent

to or surrounded by the urban interface, it is

becoming more difficult to prevent frequent

fires and subsequent habitat degradation.
28

Fire regimes are the primary ecosystem

health issue in chaparral and much has been

written on the subject (see Keeley and Scott

1995). The frequency, seasonality, size, and intensity of fires are all important. There are a

variety of different life history strategies that

assessment area and well represented on public lands (table 2.9). Only a few chaparral

associations are considered relatively rare and

poorly represented on public lands: southern

mixed chaparral, ceanothus chaparral, and serpentine chaparral.

shrub species use to survive in a fire-prone environment. Some species are short-lived, others

long-lived. Some rely primarily on resprouting

after fire; others regenerate primarily from seed

(Keeley 1986; Zedler 1995). These strategies

affect a species’ resilience to changing fire regimes. However, studies suggest that most

chaparral shrubs appear to be resilient to firereturn intervals of anywhere from twenty-five to

one hundred years (Keeley 1986; Zedler 1995).

The natural fire-return interval in chaparral is a widely debated issue, but recent research

Table 2.9. Acres of cismontane chaparral and scrub by mountain range. Values in parentheses are the percent

of those acres occurring on public lands. These figures represent land area where the specified vegetation

type is dominant. They are derived from a large-scale GIS vegetation layer that combines data from several

different mapping efforts (see “Information Sources” section, chapter 1.)

Cleveland NF Los Padres NF San Bernardino NF Angeles NF

San

Diego

 Ranges

Santa

Ana

Mts

San

Jacinto

Mts

San

Bernardino Mts

San

Gabriel

Mts

Castaic

Ranges

S. Los

Padres

Ranges

S. Santa

Lucia

Rng

N. Santa

Lucia

Rng TOTAL

Coastal sage scrub 28,174

(33%)

2,664

(2%)

18,091

(14%)

31,397

(51%)

65,714

(19%)

91,028

(52%)

21,181

(37%)

22,418

(58%)

313,627

(38%)

32,960

(25%)

Buckwheat/white sage 5,891

(90%)

7,706

(58%)

23.044

(55%)

5,058

(69%)

33,707

(68%)

105,082

(78%)

353

(84%)

209,108

(69%)

28,267

(52%)

Northern mixed chaparral 103,172

(80%)

41,092

(80%)

81,654

(79%)

253,302

(90%)

136,663

(86%)

635,929

(89%)

132,205

(78%)

184,195

(88%)

1,785,649

(83%)

217,080

(60%)

Southern mixed chaparral 5,994

(15%)

77,544

(36%)

71,550

(38%)

Chamise chaparral 54,112

(61%)

39,979

(51%)

33,735

(54%)

32,183

(84%)

57,994

(63%)

64,040

(66%)

68,286

(42%)

53,988

(63%)

534,463

(57%)

130,146

(49%)

Scrub oak chaparral 7,016

(89%)

384

(92%)

15,999

(62%)

443

(86%)

5,317

(9%)

18,003

(84%)

5,482

(89%)

3,267

(55%)

89,357

(69%)

33,446

(67%)

Montane chaparral 121

(100%)

3,928

(73%)

28,163

(90%)

23,416

(99%)

17,944

(99%)

86,824

(88%)

13,252

(52%)

Redshank chaparral 106,576

(61%)

213,654

(63%)

107,078

(66%)

Ceanothus chaparral 1,147 409 333 14,932

(18%)

3,830 2,583

(52%)

23,234

(18%)

Serpentine chaparral 7,473

(17%)

7,473

(17%)

TOTAL 204,480

(68%)

202,329

(62%)

201,903

(66%)

346,316

(86%)

299,728

(63%)

946,958

(82%)

231,337

(62%)

273,924

(78%)

3,340,754

(71%)

633,779

(54%)

Acres of Cismontane

Chaparral and Scrub

Vegetation
29

Chapter 2

Figure 2.13. Coastal sage scrub that reburns several

times in rapid succession becomes degraded and

dominated by non-native, annual grasses. JAN BEYERS

Figure 2.14. Northern mixed chaparral along the

upper San Diego River, Cleveland National Forest.

Chaparral is much denser than coastal scrub and

the shrubs have hard, woody stems. ANNE FEGE

suggests a typical interval of fifty to seventy

years (Minnich 1995; Zedler 1995; Conard

and Weise 1998). Across most of the landscape, current fire-return patterns in chaparral

appear to be either within or near this fifty to

seventy year interval. Only in fire-prone areas

adjacent to the urban interface are burns occurring more frequently.

Another widely debated issue is whether

the average size and intensity of chaparral fires

have increased as a result of fire suppression.

Some evidence suggests it has (Minnich 1989,

1995), while other evidence suggests that large

conflagrations have always dominated chaparral fire regimes (Byrne et al. 1977; Moritz

1997). This subject is addressed in detail in

the chapter 3 section on fire. Whether they

represent a change from historic conditions

or not, large fires tend to create a homogeneous vegetation pattern, with large tracts of

brush in a single age class. This simplified ageclass mosaic, while not a problem for the

shrubs themselves, reduces habitat diversity,

which generally leads to a reduction in wildlife diversity. Game animals like quail and deer,

which tend to be habitat edge species, generally avoid large, unbroken tracts of chaparral.

The continuous fuels also may make large fires

more likely to recur.

Lower Montane Forests

Bigcone Douglas-fir, Coulter pine, canyon

and coast live oak, and black oak are the primary tree species on lower mountain slopes

between 3,000 and 5,500 feet elevation in

central and southern portions of the assessment area (table 2.10). In the northern ranges,

lower montane forests can extend down to

1,000 feet elevation and contain California

bay, Pacific madrone, gray pine, and knobcone

pine (Griffin and Critchfield 1976). Often

described as mixed evergreen forests (Munz

and Keck 1973), they are typically found in

small, scattered patches (roughly 50 to 800

acres in size) surrounded by large expanses of

chaparral (fig 2.15). Thus, they are highly influenced by chaparral fire regimes.

Bigcone Douglas-fir and Coulter pine are

essentially endemic to the coastal mountains

of central and southern California (Coulter

pine extends a ways into Baja California,

Mexico) (Minnich 1987; Griffin and

Critchfield 1976). These conifer species are

rarely found together, but both are frequently

associated with canyon live oak. Both are

highly influenced by chaparral fire regimes,

but their life history strategies for responding

to fire are very different.

Bigcone Douglas-fir/canyon live oak forests frequently occur near streams in moist,

shaded canyons and draws, where aspects are

mostly north and east. At the upper end of

their elevation range these forests appear on

other aspects and become less restricted to

canyons (McDonald and Littrell 1976). They
30

Figure 2.15. Scattered patches of Coulter pine

surrounded by chaparral in American Canyon, Los

Padres National Forest. MARK BORCHERT

are evidently not well adapted to withstanding

fires and persist primarily by clinging to steep,

fire-resistant terrain (Minnich 1988;

McDonald 1990). Their ability to escape fires

sweeping through the surrounding chaparral

is due to their occurrence on precipitous slopes

and the formation of a dense, arboreal canopy

that limits understory fuel accumulation.

These stands typically have few understory

shrubs or flammable ground cover.

Bigcone Douglas-fir forests are believed to

be negatively affected by changing fire patterns

(Minnich 1988). Although there has not been

a rangewide quantitative evaluation of habitat losses, it is widely believed that bigcone

Douglas-fir has declined significantly over the

last ninety years as a result of crown fires and

poor post-fire recovery. Minnich (1999) has

documented an 18 percent decline in the extent of bigcone Douglas-fir in the San

Bernardino Mountains since 1938.

The increase in crown fires is attributed to

higher fire intensities in the surrounding chaparral, although there is little data to substantiate

this possibility (see discussion in chapter 3 section on “Fire”). The most vulnerable stands are

those on gentler slopes: Minnich (1980) observed

37 percent survival of bigcone Douglas-fir following wildfires on slopes less than 20 degrees,

Table 2.10. Acres of lower montane forest types by mountain range. Values in parentheses are the percentage

of those acres occurring on public lands. These figures represent land area where the specified vegetation

type is dominant. They are derived from a large-scale GIS vegetation layer that combines data from several

different mapping efforts (see “Infromation Sources” section, chapter 1).

Acres of Lower

Montane Forest

Types

Cleveland NF Los Padres NF San Bernardino NF Angeles NF

San

Diego

 Ranges

Santa

Ana

Mts

San

Jacinto

Mts

San

Bernardino Mts

San

Gabriel

Mts

Castaic

Ranges

S. Los

Padres

Ranges

S. Santa

Lucia

Rng

N. Santa

Lucia

Rng TOTAL

Bigcone Douglas-fir/

canyon live oak

2,650

(95%)

1.115

(95%)

12,931

(85%)

46,882

(98%)

1,872

(97%)

14,274

(98%)

88,063

(92%)

8,339

(59%)

Coulter pine/

canyon live oak

68

(100%)

12,416

(81%)

562

(100%)

19,459

(91%)

1,446

(100%)

37,200

(86%)

83,235

(77%)

12,084

(23%)

Canyon live oak woodland 2,940

(45%)

2,425

(80%)

14,346

(77%)

38,728

(95%)

15,395

(91%)

45,669

(92%)

119,515

(91%)

12

Foothill and knobcone

pine woodland

710

(63%)

170

(73%)

12,961

(18%)

10,690

(20%)

24,624

(21%)

California bay forest 197

(76%)

23,072

(77%)

23,269

(77%)

Broadleaved upland forest 91 161 45 1,596 5,332

(2%)

22,117

(7%)

36,874

(5%)

7,532

(1%)

TOTAL 5,749

(95%)

16,117

(81%)

27,415

(81%)

86,172

(97%)

17,977

(90%)

81,365

(91%)

19,739

(19%)

93,079

(57%)

375,580

(74%)

27,967

(28%)
31

Chapter 2

Table 2.11. Acres of montane and subalpine conifer forest types by mountain range. Values in parentheses

are the percentage of those acres occurring on public land. These figures represent land area where the

specified vegetation type is dominant. They are derived from a large-scale GIS vegetation layer that combines

data from several different mapping efforts (see “Information Sources” section, chapter 1).

Montane and Subalpine Conifer

Forests

Montane conifer forests consist of varying combinations of ponderosa pine, Jeffrey

pine, white fir, black oak, canyon live oak,

sugar pine, incense-cedar, and western juniper (table 2.11). These forests are the

dominant land cover type between the elevations of 5,000 and 8,500 feet in the southern

California mountains and above 3,000 feet

along the Monterey coast. Subalpine conifer

forests occur above 8,000 feet and consist of

lodgepole pine, limber pine, white fir, and

western juniper (fig. 2.16).

but more than 90 percent survival on slopes

greater than 40 degrees.

Coulter pine persists in a chaparral-dominated environment by being adapted for rapid

regeneration after fires. It has adapted to periodic crown fires by having a relatively short

life span (fifty to one hundred years) and semiserotinous cones that favor its re-establishment

after fire (Vale 1979; Borchert 1985). As a result it appears to be more resilient to today’s

fire regime than bigcone Douglas-fir.

The biggest threat to Coulter pine is multiple fires in short succession (e.g., less than

twenty-five years), that kill overstory trees before an adequate seed crop has developed. In

such cases stands can fail to regenerate and

convert to chaparral. Extreme insect or disease outbreaks can also threaten Coulter pine.

During the height of the drought in the late

1980s, a major bark beetle epidemic killed approximately 70 percent of overstory Coulter

pines on Palomar Mountain (T.White, Cleveland NF, pers. comm.). Re-establishment has

been poor in some areas, due to brush cover.

Coulter pines need openings for successful regeneration. When overstory trees die without

an accompanying fire to clear a seed bed, seedling establishment can be impaired.

Cleveland NF Los Padres NF San Bernardino NF Angeles NF

San

Diego

 Ranges

Santa

Ana

Mts

San

Jacinto

Mts

San

Bernardino Mts

San

Gabriel

Mts

Castaic

Ranges

S. Los

Padres

Ranges

S. Santa

Lucia

Rng

N. Santa

Lucia

Rng TOTAL

Mixed conifer–pine 40,082

(78%)

98,062

(76%)

20,494

(99%)

852

(99%)

159,490

(80%)

Acres of

Montane Conifer

Forest Types

Mixed conifer–fir 26,590

(85%)

53,889

(96%)

37,001

(95%)

152,863

(78%)

35,383

(26%)

Jeffrey/ponderosa pine 2,351

(43%)

58,526

(81%)

5,515

(96%)

43,507

(96%)

16,210

(68%)

141,604

(84%)

15,485

(75%)

Black oak 3,771

(88%)

4,550

(70%)

369

(96%)

1,248

(89%)

1,538

(1%)

1,014

(78%)

21,070

(60%)

8,580

(46%)

Redwood/Santa Lucia fir 16,658

(69%)

16,658

(69%)

Subalpine conifer 2,090

(100%)

5,916

(100%)

10

(100%)

234

(100%)

8,250

(100%)

TOTAL 0 48,304

(78%)

193,644

(79%)

80,277

(97%)

2,100

(93%)

80,742

(96%)

1,538

(1%)

33,882

(69%)

499,935

(79%)

59,448

(42%)
32

To validate these predictions we examined

existing and newly collected data on vegetaFigure 2.16. Continuous stands of mixed conifer

forest give way to alpine habitats on Mount San

Gorgonio, San Bernardino National Forest. JOHN

STEPHENSON

Some montane conifer stands have

changed dramatically since the early 1900s,

largely due to long-term fire exclusion

(Minnich et al. 1995). Fire suppression has

been extremely effective in upper mountain

forests. Low- to moderate-intensity understory

fires, which were historically frequent occurrences in these forests (i.e., every fifteen to

thirty years) (McBride and Lavin 1976), have

been virtually eliminated over the last sixty to

eighty years. Resulting problems include (1) a

large increase in the number of understory

trees (particularly shade-tolerant white fir and

incense-cedar); (2) increased risk of stand-replacing crown fires due to fuel buildup; and

(3) increased mortality and reduced recruitment of large trees (due to increased

understory competition).

These problems are occurring primarily in

mesic forests where understory trees develop

rapidly. Stand densities in arid, desert-side forests do not appear to be experiencing

significant change. To estimate the spatial extent of the problem, we developed a GIS-based

model to predictively map areas likely to be

experiencing overcrowded forest conditions

and associated crown fire risk. Spatial data on

vegetation type, canopy cover, annual precipitation, elevation, and slope were used to

predict potential problem areas (table 2.12)

(fig. 2.17).

tion changes at plot locations established during the Vegetation Type Map (VTM) Survey

(Weislander 1935). Approximately 18,000

VTM plots were initially surveyed from 1929

to 1934 as part of a project to map the vegetation of California (Minnich et al. 1995). They

provide a valuable record of what the vegetation structure and composition was over sixty

years ago.

Minnich et al. (1995) revisited sixty-eight

VTM plots located in montane conifer forests

in the San Bernardino Mountains. Using different methods, Savage (1994) studied this

same issue in the San Jacinto Mountains. To

obtain data from additional mountain ranges,

we revisited thirty-two VTM plots in the

Mount Pinos/Mount Abel area, the San

Gabriel Mountains, and the mountains of San

Diego County.

The results from each area were very similar: Mid-elevation mixed conifer forests have

experienced (1) substantial increases in the

number of small diameter trees (fig. 2.18), (2)

reductions in the number of large trees, and

(3) shifts in species composition towards more

white fir and incense-cedar and fewer Jeffrey/

ponderosa pine and black oak. In contrast,

plots in Jeffrey pine forests on the more arid,

desert side of the mountains showed little

change.

Subalpine forests in southern California

occur only in the highest ranges: the San

Jacinto, San Bernardino, and San Gabriel

mountains and small patches on the summit

of Mount Pinos and Mount Abel. Most of

these areas are within designated wilderness

areas, including the largest stands on the slopes

of Mount San Gorgonio. In general, these

small subalpine/alpine ecosystems are intact,

stable, and little disturbed (with the exception

of some heavy recreation use in the vicinity of

mountaintop trails). Trees grow very slowly in

these upper elevation forests and stands tend

to be open.

Fires are naturally infrequent in subalpine

forests and thus return intervals have not been

significantly altered by suppression activities.

When they do burn, it is usually in a standreplacing crown fire during severe weather
33

Chapter 2

conditions (Minnich 1988). Several crown

fires have occurred in recent decades in subalpine forests in the San Gabriel Mountains.

While the result of human-caused ignitions,

it is unclear if these fires were abnormally severe or frequent. The extremely steep terrain

in the San Gabriels may make these forests

more vulnerable as human-caused fire ignitions increase.

Figure 2.18. A look at how stem densities by size class have changed in mixed conifer stands over the

last sixty years. The left graph comes from VTM plots done in the early 1930s and the right graph comes

from those same locations in 1997 (n = 7). Each bar represents +/- one standard deviation from the

mean; the mean is indicated by the horizontal line through each bar. Pronounced increases in stem

densities have occurred in the small diameter size classes, while the number of large diameter (>90

cm) trees has slightly declined. These results are from the mountains of San Diego County, but the

same trend is seen in plot data from the San Bernardino Mountains (Minnich et al. 1995), the San

Gabriel Mountains and Mount Pinos.

Areas predicted to be experiencing high stand densification meet all of the following

conditions:

1. Vegetation type is a conifer forest (but not bigcone Douglas-fir or pinyon/juniper)

2. Elevation is at or below 7,500 feet

3. Average annual precipitation is greater than 65 centimeters (25.6 inches)

4. Canopy cover is greater than 60 percent

5. Slope is less than 60 percent

Table 2.12. Description of the model conditions used to predict areas of montane conifer forest

with overcrowded stand conditions. The map of predicted areas is shown in figure 2.17.

Desert Montane Communities

Arid slopes on the desert side of the mountains are occupied by sparse pinyon-juniper

woodlands, semi-desert chaparral, sagebrush,

and desert scrub (table 2.13). Single-leaf pinyon pine generally dominates the higher

elevation slopes, while California juniper is

prevalent at lower elevations, often on gentle

slopes or alluvium. Parry or four-needle pinyon pine occurs in the San Jacinto Mountain

region’s desert transition zone near Thomas

Mountain.

1997

0

100

200

300

400

500

600

10-2930-5960-89

<90

Diameter at breast height (cm)

Stems per hectare

Grand Total 

1930s

0

100

200

300

400

500

600

10-2930-5960-89

<90

Diameter at breast height (cm)

Stems per hectare

Grand Total
34

Bernardino Mountains (Fenn 1991a; Merrill

et al. 1992).

Semi-desert chaparral is more open than

chaparral found on coastal slopes and has a

different mix of species. Flannel bush, bitterbrush, Tucker or Miller scrub oak, birchleaf

mountain mahogany, and cupleaf ceanothus

are characteristic components of semi-desert

chaparral (Sawyer and Keeler-Wolf 1995).

Basin sagebrush is common in dry alluvial

fans, meadows, and washes. Basin sagebrush

is particularly prevalent in the low elevations

surrounding Mount Pinos and in the Garner

Valley region south of Mount San Jacinto.

There is no evidence that fire regimes in these

vegetation types are outside the range of natural variability.

Common land uses in desert-side habitats

are mining, off-highway vehicle (OHV) recreation, and target shooting. Large limestone

deposits in the northeastern portion of the San

Bernardino Mountains have resulted in the

development of several major open-pit mines.

Exploratory drilling for oil and gas deposits is

a major activity in the southern Los Padres.

These activities have caused habitat losses and

are affecting sensitive resources in some

Pinyon-juniper woodlands are generally

open-canopy stands with sparse understory

vegetation. It is not a vegetation structure that

carries fire well and pinyon pine is not adapted

to frequent fire. Fire-return intervals of several hundred years are considered typical in

these woodlands (Minnich 1988).

There have recently been several large fires

in pinyon stands in the San Bernardino Mountains. One area even reburned several years

after a crown fire (S. Loe, San Bernardino NF,

pers. comm.), which is very unusual in such

sparsely vegetated habitat. This has raised concern about whether the spread of introduced

grasses (primarily cheatgrass) is providing the

fuels needed for fire to carry more effectively

and frequently in these stands. If this is occurring, it would only be in years of high

precipitation when there is sufficient moisture

for the grass to become widespread. It is unclear if this is actually happening, but the issue

warrants further study because pinyon-juniper woodlands are extremely slow to recover

from fire and would be negatively affected by

shortened fire-return intervals. Black stain root

disease is also a significant problem for pinyon pine, particularly in portions of the San

Table 2.13. Acres of desert-side montane vegetation types by mountain range. Values in parentheses are the

percentage of those acres occurring on public lands. These figures represent land area where the specified

vegetation type is dominant. They are derived from a large-scale GIS vegetation layer that combines data

from several different mapping efforts (see “Information Sources section, chapter 1).

Cleveland NF Los Padres NF San Bernardino NF Angeles NF

San

Diego

 Ranges

Santa

Ana

Mts

San

Jacinto

Mts

San

Bernardino Mts

San

Gabriel

Mts

Castaic

Ranges

S. Los

Padres

Ranges

S. Santa

Lucia

Rng

N. Santa

Lucia

Rng TOTAL

Pinyon woodland 13,225

(83%)

57,776

(89%)

26,065

(79%)

17,029

(12%)

236,780

(86%)

351,337

(82%)

444

(91%)

Semi-desert chaparral

and Tucker scrub oak

37,354

(67%)

50,021

(83%)

48,569

(70%)

5,332

(20%)

78,632

(86%)

160

(57%)

247,182

(78%)

27,114

(83%)

Basin sagebrush 15,416

(30%)

8,282

(76%)

2,856

(37%)

1,678 15,373

(54%)

50,466

(43%)

6,861

(25%)

Desert scrub 26,170

(52%)

4,466

(47%)

54 35,658

(58%)

4,968

(100%)

TOTAL 92,165

(59%)

120,545

(84%)

77,544

(72%)

24,039

(13%)

330,785

(85%)

160

(57%)

0 684, 643

(77%)

39,387

(75%)

Acres of Desertside Montane

Vegetation Types

0
35

Chapter 2

locations, but from a broad ecosystem perspective they are relatively localized.

Target shooters and OHV enthusiasts tend

to concentrate in desert-side habitats because

the sparsely vegetated terrain is conducive to

these activities. Uncontrolled target shooting

has raised safety and pollution (particularly

from lead accumulation) concerns and several

of the national forests are currently reviewing

their policies on this activity.

Monterey Coast Communities

The northern Santa Lucia Range along

the Monterey coast receives substantially

higher amounts of precipitation than the rest

of the assessment area and thus contain plant

communities that are more similar to those

found in northern California. Along the immediate coast, narrow stands of redwood trees

occur in deep canyons surrounded by coastal

scrub, chaparral, and grassland.

On the inland side of the mountain crest,

stands of ponderosa pine, the endemic Santa

Lucia fir, and true Douglas-fir (a different

species than bigcone Douglas-fir) occur at the

highest elevations. Below the conifer belt on

the inland side of the mountains is a mosaic

of chaparral, mixed evergreen forest, and oak

woodland. California bay, Pacific madrone,

and live oak are common components of the

evergreen forest. This is the only place in the

assessment area where Douglas-fir and madrone are common trees.

Although fires are generally smaller and

less frequent in this mesic area, a single event

(the approximately 180,000-acre Marble

Cone fire) burned much of the region in the

late 1970s (Griffin 1982; Moritz 1997). It is

unclear if this is a typical historic pattern, but

there is little evidence to suggest that the area

is experiencing vegetation changes as a result

of shifting fire regimes.

Rugged terrain in the area historically limited road development and led to the

establishment of the Ventana Wilderness,

which encompasses the majority of the northern Santa Lucia Range. Land use in this region

is relatively limited and strongly recreation oriented. The Big Sur coastline receives most of

the recreation activity.

Aquatic and Riparian

Communities

Freshwater aquatic habitats are uncommon in coastal southern California and most

have been substantially modifed by altered

stream flow regimes. Essentially all the large

rivers are to some extent dammed or diverted

(figs. 2.19–20), thereby significantly altering

the extent and character of riverine habitats

(see section on “The Influence of Water Regulation and Withdrawal” in chapter 3).

Deep-water reservoirs formed by dams are a

new and entirely different type of aquatic habitat that didn’t exist historically in the region.

The aquatic fauna found in these reservoirs

tends to be dominated by non-native species.

Given the dominant role that impoundments have in determining a drainage’s habitat

potential, we partitioned streams into analysis watersheds based on whether they occurred

above or below major impoundments. A database was developed that provides baseline

information on each analysis watershed and the

major streams occurring within them. Information compiled for each stream includes linear

miles by elevation intervals, percent on public

land, occurrence of roads along the stream corridor, land use intensity, degree of stream flow

alteration, and level of non-native species infestation. Information on each watershed includes

the percent of the entire watershed that is on

public land, road densities in the watershed, and

occurrences of both species of concern and invasive non-native species. A complete table of

the data compiled for each watershed and stream

is provided in appendix C.

Streams and Rivers

Most streams in southern California have

very low flow during the summer months and

in many cases dry up in the lower and uppermost portions. However, streams that flow

through rock canyons often have perennial

flow because deep pools are fed by groundwater recharge. This pattern of low flow in
36

Figure 2.19. The primary rivers and streams in the southern portion of the assessment area with the underlying

public lands. Shown in red are locations of dams (circles) and major diversions (triangles). Baldwin Lake, the

only large natural lake in the region, can be seen in the upper right, just west of Arraste Creek.

summer, which reflects the Mediterranean climate, results in an interesting situation in

which the headward parts of streams may be

dry, the middle portion wet, and the low portion dry during the summer months (Faber et

al. 1989).

The middle and lower portions of these

streams, typically found at elevations below

3,000 feet, support a higher number of aquatic

and riparian species. Perhaps because habitat

loss has been so extensive there, low-elevation

streams also have a much higher number of
37

Chapter 2

Figure 2.20. The primary rivers and streams in the northern portion of the assessment area with the underlying

public lands. Shown in red are locations of dams (circles) and major diversions (triangles).

associated threatened, endangered, and sensitive (TES) animal species (table 2.14).

Landownership patterns and threat factors also differ dramatically by elevation.

Seventy-four percent of stream miles above

3,000 feet elevation are on public lands, but

this proportion drops to 50 percent between

1,000 and 3,000 feet, and down to 17 percent below 1,000 feet (fig 2.21). The lowelevation rivers also face greater threats.

Water flows are much more likely to be diverted or altered, the adjacent terraces are

commonly farmed or developed, and there is

a greater abundance of invasive non-native

species.
38

Given the significance and rarity of hydrologically intact low-elevation streams, those

occurring on public lands should be given

special attention. Of particular import are the

sections of these streams that are in a relatively

unmodified state. These are the areas where

historic disturbance regimes and the natural

range of variability may still be possible to

maintain. To identify these areas we used GIS

data to select the low-elevation streams best

represented on public lands and the sections

of them that do not contain upstream dams

or diversions. Then we considered information on land use intensity, invasive species, and

landownership patterns in the upstream watershed (table 2.15).

The streams listed in table 2.15 are not

necessarily the most important ones in terms

of TES species populations. However, the hydrologically unregulated sections of these

streams are likely to be the best remaining examples of intact low-elevation aquatic

ecosystems in the central and southern California coastal region. Thus, they represent our

best opportunities for maintaining intact

aquatic ecosystems.

Next to alteration of stream flow, the biggest factor threatening the health of native

aquatic ecosystems is the spread of invasive

Figure 2.21. Bars show the miles of all streams

along the central and southern California coast by

elevation group. The shaded portion is the

proportion that occurs on public land, with the

percent value shown above it. The occurrence of

streams on public lands increases dramatically with

elevation.

non-native species. Invasive aquatic animals

that are causing problems in many streams

include green sunfish, bluegill, bullfrogs, crayfish, mosquitofish, brown trout, bass,

bullheads, red-eared sliders, and African

clawed frogs. The invasive plants arundo and

tamarisk are also spreading, displacing native

vegetation and causing a decline in surface

Table 2.14. Threatened, endangered, and sensitive (TES) aquatic and semi-aquatic animal species that

are associated with either low- or high-elevation streams.

Aquatic TES animals found primarily in

low-elevation streams (<3,000 ft)

California red-legged frog

Foothill yellow-legged frog

Coast range newt

Southwestern arroyo toad

Santa Ana sucker

Santa Ana speckled dace

Arroyo chub

Southern steelhead

Unarmored threespine stickleback

California red-sided garter snake

Southwestern pond turtle

Aquatic TES animals found primarily in

high-elevation streams (>3,000 ft)

Mountain yellow-legged frog

Shay Creek stickleback

50% 74%

17%

0

500

1000

1500

2000

2500

Streams

below

1,000 ft

Streams

1,000 to

3,000 ft

Streams

above

3,000 ft

miles of stream

on private land

on public land
39

Chapter 2

water availability in some streams (Rieger and

Kreager 1989). Collectively, these introduced

species are causing a serious decline in the capability of aquatic habitats to support native

species.

Table 2.15. The most significant low-elevation (below 3,000 feet) streams from the standpoint of

linear miles on public lands. Those in bold are identified as having relatively high potential for maintaining

aquatic ecological integrity, due to a high amount of unregulated streamflow (i.e., not dammed or

diverted).

Lakes

Almost all lakes in the assessment area are

man-made reservoirs formed by dams. However, a few small natural basins exist that hold

water all or most of the time. The majority of

these straddle the San Andreas Fault: Jackson

 * These streams are predominately on military lands.

** The flow on the Santa Margarita is partially diverted by a dam on Temecula Creek.

San Antonio River* No. Santa Lucia 56.0 47.7 64% Mod ?

Nacimiento River* No. Santa Lucia 34.6 25.1 48% Mod ?

Piru Creek So. Los Padres 26.6 7.3 80% High High

Sisquoc River So. Los Padres 26.4 26.4 87% Low Low

Santa Ynez River So. Los Padres 26.1 0 High High

Big Sur River (S & N fks) No. Santa Lucia 25.7 25.7 93% Low Low

Sespe Creek So. Los Padres 23.9 23.9 91% Mod Mod

San Mateo Creek Santa Ana Mts. 22.8 22.8 92% Low Mod

Santa Margarita River** San Diego Ranges 21.4 21.1** 38% Mod High

Santa Ana River San Bernardino Mts. 17.6 0 87% Mod High

San Gabriel River San Gabriel Mts. 17.6 12.5 95% High Mod

Arroyo Seco No. Santa Lucia 16.5 16.5 60% Mod Mod

West Fk, San Gabriel R. San Gabriel Mts. 15.7 6.0 100% Mod Mod

Cuyama River So. Los Padres 14.8 4.5 70% Mod ?

Manzana Creek So. Los Padres 14.3 14.3 100% Low Low

Carmel River No. Santa Lucia 14.0 5.0 49% Mod Low

Elizabeth Lake Liebre Mtn. Area 13.4 13.4 84% High Mod

Salinas River N&S Santa Lucia 13.1 2.2 22% High High

San Diego River San Diego Ranges 13.0 7.9 42% Low/Mod Mod

Mono Creek So. Los Padres 13.0 13.0 96% Low Low

San Juan Creek Santa Ana Mts. 12.2 12.2 52% High Mod

Big Tujunga Creek San Gabriel Mts. 11.4 0 87% High High

Pine Valley Creek San Diego Ranges 10.3 10.3 81% Low Mod

Indian Creek So. Los Padres 9.5 9.5 100% Low Low

Santa Cruz Creek So. Los Padres 9.4 9.4 58% Mod ?

Invasive

Species

Infestation

Stream Miles below 3,000ft

Stream Mountain Range

Subarea

On

Public

Land

(Total mi)

Flow

Undiverted

on Public

Land

% Public

Land in

Watershed

Land Use

Intensity
40

Riparian habitats have declined dramatically at low elevations, where they historically

were most extensive. It is estimated that

channelization and diversion of streams in the

last century have reduced the extent of riparian habitats in southern California by over 90

percent (Faber et al. 1989). More recently,

strong regulatory policies on “no net loss” of

wetlands have helped to check this decline.

The extent of riparian habitats on public

lands is relatively stable. So too is the structural condition of these habitats. Livestock

grazing in riparian areas within the national

forests has been substantially reduced, resulting in some dramatic improvements in

vegetation condition. Concentrated recreation

use is causing localized habitat damage in some

areas. Foothill riparian areas are cool, pleasant places in the vicinity of large urban

populations so recreation pressure is inevitable.

Low-Elevation Riparian Habitats

Riparian habitats reach their peak as distinct ecological communities along mid- to

large-order streams below 4,000 feet in the

foothills and valleys. There are many different riparian plant associations (table 2.7), but

foothill riparian woodlands generally fall into

one of three broad categories: (1) Fremont cottonwood/willow, (2) California sycamore/

coast live oak and (3) white alder (Borchert

unpubl. manuscript). They are extremely productive and important habitats for wildlife (see

Faber et al. 1989 for an excellent overview of

southern California riparian habitats).

Figure 2.22. Linear riparian woodlands like this one

in San Francisquito Canyon, Angeles National Forest,

contrast sharply with the surrounding arid

shrublands. SHAWNA BAUTISTA

Lake, Elizabeth Lake, Lake Hughes, and Lost

Lake. In addition, Crystal Lake in the San Gabriel

Mountains, Dollar Lake in the San Bernardino

Mountains, and Hidden Lake in the San Jacinto

Mountains are small natural lakes.

There is one large natural, ephemeral lake

in the mountains: Baldwin Lake in the eastern San Bernardino Mountains. This large

shallow basin fills with water during wet periods. It can retain water year-round for several

years when conditions are right. When full,

its shallow waters attract large numbers of waterfowl and also provide habitat for the rare

Shay Creek stickleback fish. The watershed

that feeds Baldwin Lake is also the primary

water supply for the community of Big Bear

City. This may be resulting in reduced flows

into the lake.

The large, man-made lakes are essentially

distinct ecosystems, with an aquatic fauna that

bears little resemblance to what naturally occurs in the streams that formed them. Almost

all support fisheries and are stocked with various species of bass, trout, catfish, and sunfish.

Fishing is a very popular recreational activity

at many of these lakes, attracting far more anglers than do the streams. The lakes have also

attracted species such as bald eagle and osprey

that were formerly very rare in these mountains. These lakes also facilitate the

introduction of a wide variety of invasive nonnative species into the surrounding streams

(see “Invasive Species” section, chapter 3).

Riparian ecosystems are linear and often

narrow features on the landscape (fig. 2.22).

For that reason, they are difficult to accurately

map across large areas using air photos or satellite imagery. Our existing vegetation maps

do not fully capture the distribution of riparian habitats; thus, we have not attempted to

provide acreages for them. A detailed map of

riparian plant communities would be extremely useful for management purposes.

Related information on the extent of rivers and

streams in the region is provided in the section on aquatic ecosystems.
41

Chapter 2

However, habitat degradation tends to be localized in a few popular, easily accessible areas.

A more insidious and widespread problem is the spread of invasive, non-native

species. The brown-headed cowbird, which

parasitizes the nests of native birds, and European starlings, which displace native

cavity-nesting birds, are causing declines in

habitat capability in many areas. Bullfrogs,

African clawed frogs, and green sunfish are

spreading in many drainages, causing large

impacts on native amphibians, aquatic reptiles, and fish. Arundo (giant cane) and

tamarisk are invasive plants that are

outcompeting native riparian vegetation in

some areas. Arundo in particular is spreading

rapidly in low-elevation riparian areas.

Twelve rare ecological communities were

identified in the assessment area. Communities

fall into this category if there is some concern

over their ability to persist in the region. Four

are defined by unusual soils and eight are plant

communities either narrowly distributed within

the assessment area or threatened in a portion of

their natural range. Acreage estimates for the

twelve communities are summarized in table

2.16 and brief descriptions follow.

Valley Oak Woodlands

Valley oak (Quercus lobata) is endemic to

California, occurring in areas with relatively

mild winters west of the Sierra Nevada Mountains (Axelrod 1977). The species forms

extensive woodlands, some of which occur in

the northern half of our assessment area.

Table 2.16. The extent and distribution of rare community types on public lands. Acreages are derived

from GIS coverages of vegetation, species, and soils distributions.

Valley oak woodlands unknown <20% 8% (680)

Engelmann oak woodlands 53,8102 82% 12% (6,461)3

Black walnut woodlands 23,5694 17% 12% (2,828)

Cuyamaca cypress groves 230 100% 100%

Tecate cypress groves 6,758 15% 85% (5,744)

Gabbro outcrops 81,680 55% 41% (33,489)

Montane meadows 55,446 100% 38% (21,070)

Pebble plains 379 100% 60% (227)

Limestone/carbonate 20,893 90% 87% (18,177)

 outcrops

Serpentine outcrops unknown (31,470)

Sargent cypress groves 1,585 100% 74% (1,173)

Santa Lucia fir forests 7,576 100% 95% (7,197)

1

 based on bioregions as defined by the California Bioregional Council

2

 calculated using top four cover classes (3, 4, 5, and 6) from Scott (1990)

3

 includes private reserves (e.g., portions of the Santa Rosa Plateau)

4 from mapped polygons by Weislander (1935)

Rare Communities

Total Mapped

Acres in Central

and South Coast

Bioregions1

Percent within

Assessment

Area

Percent on Public

Lands within

Assessment Area

(acres)

Rare Communities
42

Figure 2.23. Valley oak woodland at Wagon Caves

Candidate Research Natural Area, Los Padres National

Forest. MARK BORCHERT

Valley oak frequently forms open woodlands with a grass-dominated understory.

These oak savannas are often the dominant

plant community in broad valleys that surround the mountains of Santa Barbara, San

Luis Obispo, and Monterey counties. Along

drainages the species forms denser riparian

forests (Holland 1986) and is often found

with blue oak, black oak, coast live oak, sycamore, and black walnut (Sawyer and

Keeler-Wolf 1995).

Valley oak woodlands are poorly represented on public lands, although a more

detailed mapping effort is needed to better

quantify the exact amount. On private lands,

the rapid expansion of agriculture and urban

development along the central coast is causing a serious reduction in the extent of these

woodlands (R. Cowan, The Quercus Group,

in litt. 1998). For example, the clearing of

oak savannas for large vineyard operations is

occurring in the foothills and valleys of Santa

Barbara County. More than 2,500 oaks in the

Santa Ynez and Los Alamos valleys have been

felled during the last two years and county

officials predict vineyard acreage to triple

within ten years (Cannon 1998). These areas

are outside the assessment area but illustrate

the importance of valley oak conservation on

public lands.

Tree regeneration is also considered a problem in valley oak woodlands. Many stands are

reported to be especially devoid of trees established in the last 75 to 125 years (Pavlik et al.

1991). Factors cited as contributing to this lack

of regeneration include consumption of acorns

and seedlings by livestock, tilling of cropland

around mature trees, lowering of the water

table through groundwater pumping, and

competition from non-native grasses and other

exotic species (C. Blair, CNPS, in litt. 1998).

The presence of non-native annual grasses in

native grasslands has been shown to increase

oak seedling mortality by limiting the availability of soil moisture (Danielsen and

Halvorson 1991). Non-native annual grasses

grow and utilize soil moisture faster than native perennial grasses. Oak seedlings exposed

to rapid declines in soil moisture experience

water stress and display reduced growth. In

controlled experiments, Danielsen and

Halvorson (1991) found that valley oak seedlings were significantly larger when growing

in association with native purple needlegrass

(Stipa pulchra) than when grown with wild oats

(Avena fatua).

Engelmann Oak Woodland

Engelmann oak (Quercus engelmannii)

woodlands are distributed from the San

Gabriel Mountains south to Baja California,

Mexico; however, most occur in the foothills

Valley oaks are most prevalent at low elevations in the Santa Lucia Ranges but also extend

into portions of the southern Los Padres and

Castaic regions, and the northern flank of the

San Gabriel Mountains (Hickman 1993; Griffin and Critchfield 1972). The southernmost

occurrences of valley oak woodland are found

in Los Angeles County in the San Fernando

and Santa Clarita valleys and the Santa Monica

Mountains (Pavlik et al. 1991).

True to its name, this tree typically occupies valley floor and lower foothill

communities where there are deep soils (fig.

2.23). Its distribution also appears to be associated with shallow water tables (Griffin 1977).

Valley oaks do extend up the mountain slopes

in places. They occur at 5,000 feet on Chews

Ridge in the northern Santa Lucia Range and

extend up to 5,600 feet in the Tehachapi

Mountains.
43

Chapter 2

of San Diego and southwestern Riverside

counties (fig. 2.24). Populations also occur on

Santa Catalina Island. The greatest concentration of these woodlands is found in the

foothills of San Diego County between

Palomar Mountain and Cuyamaca Peak. Another major occurrence is located on the Santa

Rosa Plateau on the southeastern flank of the

Santa Ana Mountains. The species is the only

representative of subtropical white oaks in

California and represents the northwestern

extent of their range (Scott 1990).

Figure 2.24. The distribution of Engelmann oak and black walnut in southern California.

Engelmann oaks are found at elevations

ranging from 160 to 4,500 feet on valley floors,

foothill slopes, and raised stream terraces

within riparian corridors (Scott 1989; Sawyer

and Keeler-Wolf 1995). They commonly form

open savannas (less than 10 percent canopy

closure) and woodlands (greater than 10 percent canopy closure) with grassland

understories (R. Cowan, The Quercus Group,

in litt. 1998)(fig. 2.25). In riparian areas the

species can occur in dense stands with other

hardwoods (Holland 1986).

Some of the most successful stands of

Engelmann oak grow on clay soils formed

from a gabbro or basalt substrate (St. John

1992). In San Diego County the species is

sometimes found on rocky, north-facing slopes

with an understory of coastal sage scrub or

chaparral. In these instances it often hybridizes with scrub oak or Muller’s oak.
44

Acreage estimates for this woodland type

vary depending on whether Engelmann oak

is mapped everywhere it occurs or just where

it is the dominant tree. Based on our GIS vegetation layer, Engelmann oak woodland is the

dominant vegetation type over an estimated

21,083 acres—17,054 acres in San Diego

County and 4,029 acres in the Santa Rosa Plateau region. In contrast, Tom Scott used aerial

photographs and ground-truthing to map approximately 78,000 acres that contain at least

some Engelmann oak (it was subdominant to

coast live oak in over half of this area)(Scott

1989). Rarely does the species occur in pure

stands (over less than 1,300 acres based on

Scott’s map). Seventy-eight percent of the Engelmann oak mapped by Scott occurs within

the assessment area, with the remaining acres

located to the west in more coastal areas of

San Diego County.

Engelmann oak woodlands are declining

primarily due to habitat loss on private lands.

Eighty-eight percent of Engelmann oak habitat in the assessment area is located on private

land (Scott 1989). The tree inhabits the smallest natural range of any oak species in

California and is located next to the fastest

growing urban landscape in the country (Scott

1990). Encouraging private landholders to

protect this species on their properties is key

to conserving Engelmann oak (T. Scott, UC

Riverside, in litt. 1998). In addition, it is important for public land management agencies

Figure 2.25. A mix of Engelmann and coast live

oak form a relatively open woodland on the

Rutherford Ranch, Cleveland National Forest. STAN

CALHOUN

to pursue acquisition of lands containing Engelmann oak when they come up for sale. In

recent years, major progress has been made in

conserving this species through the purchase

of key areas by Riverside County (on the Santa

Rosa Plateau), San Diego County (on Volcan

Mountain), CalTrans, and the Cleveland National Forest (Roberts and Rutherford

ranches).

The primary management concern for

Engelmann oak woodlands on public lands is

maintaining sufficient regeneration. The longterm viability of Engelmann oak appears to

be hampered by sporadic regeneration combined with unnatural rates of disturbance.

Livestock grazing and competition for soil

moisture from introduced annual grasses both

appear to cause low recruitment rates for the

species and there is a noticeable absence of

young trees in many woodlands (Lathrop and

Osborne 1990; Pavlik et al. 1991).

Walnut Woodland

Black walnut (Juglans californica var.

californica) woodlands are an uncommon foothill habitat that is distributed from Santa

Barbara County south to northern San Diego

County (fig. 2.24). The easternmost stands

occur in southwestern San Bernardino County

in Day, Etiwanda, and San Sevaine canyons

at the foot of the San Gabriel Mountains.

Large stands also occur in Ventura, Los Angeles, and northern Orange counties (Quinn

1989; Keeley 1990). Woodlands are scattered

in low foothills surrounding the Santa Clara

River drainage (including the Santa Susana

and Sulphur mountains), in the Santa Ynez

Mountains, along the north side of the Santa

Monica Mountains, along the base of the San

Gabriel Mountains, and in the Simi, San Jose,

Puente, and Chino hills. Other stands occur

within the lower foothills of the southern Los

Padres and Castaic regions.

Black walnut can be the dominant tree in

the canopy or occur in mixed stands with other

hardwoods such as coast live oak (fig. 2.26).

At Los Pinetos Spring in the western San

Gabriel Mountains, walnut grows with

bigcone Douglas-fir and canyon live oak
45

Chapter 2

(S. Boyd, Rancho Santa Ana Botanic Garden,

pers. comm.). Some isolated stands occur

within chaparral and coastal sage scrub (Esser

1993). Walnut usually occupies mesic areas

(i.e., riparian corridors, floodplains, and

north-facing slopes) and prefers soils with a

high clay content.

Figure 2.26. Southern California black walnut

woodland at California State Polytechnic University,

Pomona. JANET NICKERMAN

Walnut woodlands are considered a declining plant community due to habitat loss

on private lands and low representation on

public lands. Small populations are located on

the Angeles, San Bernardino, and Los Padres

national forests but quantitative data is available only for the Los Padres National Forest.

This data is based on Weislander maps developed in the 1930s and probably represent

rough acreage estimates (Weislander 1935). A

better determination of the current distribution of this community is needed. Of the

23,569 acres mapped in southern California,

only 12 percent are located on public lands.

The great majority of walnut woodlands

are found in urban interface areas.

Devegetation of private lands for development

appears to be the primary threat to this community. The tree has high horticultural

potential, however, sometimes being incorporated into urban forestry projects, and private

landowners are being encouraged to retain

these woodlands as part of their landscaping.

Lack of sufficient regeneration is another

problem observed in some walnut woodlands.

It is unclear whether the regeneration problem is caused by livestock grazing, invasion of

non-native annual grasses, seedling predation,

Cuyamaca Cypress Groves

In the strict sense, Cuyamaca cypress

(Cupressus stephensonii) is known only from

the Cuyamaca Mountains of San Diego

County and is the most narrowly distributed

cypress in California. Some taxonomists believe, however, that the tree is really an Arizona

cypress variant (C. arizonica ssp. arizonica).

This variant also occurs in the southern Sierra

Juarez east of Santa Catarina (R. Minnich, UC

Riverside, in litt. 1998). In this sense

Cuyamaca cypress may be part of a larger species range that includes occurrences in Arizona,

neighboring Sonora, and the Sierra Juarez.

Cuyamaca cypress forms several groves in

the Cuyamaca Peak/King Creek area in the

mountains of San Diego County (fig. 2.27).

The groves represent a single population that

occurs naturally over an estimated 230 acres

on both the Cleveland National Forest and

Cuyamaca Rancho State Park (Winter 1994).

In 1991 the Cleveland National Forest established the King Creek Research Natural Area

to protect the cypress and its habitat. An apparently introduced population occurs in the

Agua Tibia Wilderness near Palomar Mountain.

or disease, and it may prove to be a combination of factors. Intensive livestock grazing in

walnut woodlands has been shown under certain conditions to lower the survival rates of

walnut seedlings by direct herbivory and by

the introduction of non-native taxa into the

understory (Esser 1993). Conversion from a

native perennial grass understory to one dominated by non-native annual grasses is believed

to be a primary cause of low regeneration in

walnut woodlands much the same way it has

affected oak woodlands (L. Merrill, San Bernardino NF, in litt.). A walnut woodland at

Hopper Mountain on the Los Padres National

Forest contains a large amount of Avena but

very little if any walnut seedlings.

The effects of existing fire regimes on walnut are poorly understood. The variety is

top-killed by most fires but reproduces vegetatively from the root crown and trunk after

burning (Esser 1993).
46

Like all native cypress in California,

Cuyamaca is adapted to fire and produces serotinous or closed cones at maturity (Zedler

1986). These cones require the intense heat

generated by fire to open and disperse their

The tree usually grows in gabbro-derived

clay soils, on steep slopes along drainages. It

can be dominant in the canopy or co-dominant with Coulter pine. Groves are typically

surrounded by chaparral vegetation composed

of chamise, manzanita, and scrub oak (fig.

2.28). Two other rare plants, Dunn’s mariposa

lily (Calochortus dunnii) and Orcutt’s brodiaea

(Brodiaea orcuttii), are found with Cuyamaca

cypress.

Figure 2.27. The distribution of gabbro soils, Cuyamaca cypress, and Tecate cypress in southern California.

seed as well as to prepare the soil for enhancement of germination. While periodic fires are

therefore necessary for regeneration, short firereturn intervals (e.g., less than every forty years)

appear to gradually decrease stand densities by

preventing trees from reaching maturity and

producing seed (Winter 1994). The species has

relatively thin, exfoliating bark that provides

little protection from fire and is usually killed

in wildfire events (Sullivan 1993b). Since trees

typically reach maturity and begin to produce

viable seed at approximately forty years, a firefree interval of greater than forty years is

needed to maintain the seed pool/bank.
47

Chapter 2

Figure 2.28. Cuyamaca cypress and chaparral at King

Creek, Cleveland National Forest. These young trees

germinated after the 1970 Boulder Fire. MOZE MOSSAY

R. Minnich, UC Riverside, in litt. 1998).

Usually found on mesic east- or north-facing slopes, Tecate cypress grows in alkaline,

clay soils derived from ultramafic gabbroic

rocks or metavolcanics (Zedler 1981)(fig.

2.29). The tree was once more widespread but

is now restricted to these unusual soils where

it lacks competition (Schoenherr 1992). Like

Cuyamaca cypress, Tecate can be the defining

component of southern interior cypress forest—a dense, fire-maintained low forest that

forms even-aged stands surrounded by chaparral (Esser 1994a). Ceanothus, scrub oak, and

chamise species are commonly found with

Tecate cypress, and the trees may also be

viewed as a phase of chaparral vegetation

(Zedler 1981).

Tecate cypress is strongly influenced by

fire; seeds remain in the cones until fire causes

them to be dispersed and the trees themselves

are killed. Environmental conditions present

after fire induce the seeds to germinate and

re-establish the population. Despite this adaptation to fire, the species is vulnerable to

either excessively short or long fire-return intervals (Zedler 1981). Under current

conditions, overly frequent fire is the much

greater threat. Tecate cypress trees begin to

produce cones after about ten years but take

about fifty years to reach maximum cone production (Zedler 1977). If they reburn at

intervals less than fifty years, reduced amounts

of viable seed for regeneration would be expected.

Cuyamaca cypress is an increasingly rare

species within the assessment area. The Cleveland National Forest has developed a species

management guide that summarizes approaches to fire management and provides

guidelines for the use of fire in enhancing cypress stands on the forest (Winter 1994).

Tecate Cypress Groves

Tecate cypress (Cupressus forbesii) occurs

at elevations as low as 65 feet in Baja California, Mexico, and up to 4,200 feet in the San

Diego and Santa Ana mountains (J. Gibson,

San Diego Natural History Museum, pers.

comm.). Its distribution is centered in Baja;

however, some significant colonies are found

north of the border. A 50-acre grove on Guatay

Mountain in San Diego County and a 960-

acre occurrence in the Sierra Peak/Coal

Canyon area of the northern Santa Ana Mountains are located in the assessment area (fig.

2.27). Groves in the Sierra Peak/Coal Canyon area represent the northern limit of Tecate

cypress distribution and its only Orange

County locality (White 1990). The largest

stand of Tecate cypress in California (over

5,000 acres) is south of the assessment area at

Otay Mountain along the border with Mexico.

Most of that occurrence is situated on land

managed by the BLM. Numerous groves of

Tecate cypress occur on the Mexico side of

Otay and Tecate peaks and in the coastal

mountains of Baja California, extending about

150 miles down the peninsula (Esser 1994a;

Eighty-five percent of Tecate cypress

within the United States is located on public

lands yet the species is becoming increasingly

rare in these areas (K. Winter, Cleveland NF,

unpubl. notes). Reduced stand densities are

attributed mainly to increases in fire frequency.

Data collected at both Tecate Peak and Otay

Mountain suggests that some of the groves

there are diminishing in size. Using fire history records, ring counts, and aerial

photographs, Paul Zedler was able to determine the burn intervals at Tecate Peak from

approximately 1800 through 1975, and at

Otay Mountain from 1943 to 1976 (Zedler
48

A potential threat to gabbro habitat on

national forest system lands is the construction of communication sites on mountaintops.

Impacts to the habitat in other areas are largely

unknown. Strip mining of gabbro-derived clay

deposits has occurred on private lands in the

northern and eastern Santa Ana Mountains

(Esser 1994a) and there is potential for increased mining to occur.

Montane Meadows

Montane meadows are found throughout

the assessment area, typically at elevations

above 3,200 feet, and are represented on all

Figure 2.29. Mature Tecate cypress on Otay

Mountain, San Diego County. MILAN MITROVICH

(Mitoura thornei) are found exclusively with

Tecate cypress; however, the butterflies have

only been observed in the grove on Otay

Mountain, outside the assessment area

(Murphy 1990).

Gabbro Outcrops

Gabbroic rock exposures are found in the

foothills and mountains of San Diego County

and the Santa Ana Mountains (fig. 2.27). In

the San Diego region the substrate is known

from Cuyamaca, Guatay, McGinty, Potrero,

Viejas, Poser, Los Pinos, Corte Madera, and

Iron mountains (Beauchamp 1986). An estimated 81,680 acres of gabbro-derived soils

occur in southern California. Forty-one percent of those acres are found on public lands,

most within the Cleveland National Forest.

Commonly called gabbro, the igneous

rock is highly erodable and weathers into a

dark reddish, iron- and magnesium-rich soil

(Schoenherr 1992)(fig. 2.30). The soil is sometimes characterized as a poorly draining clay.

Soil series formed from gabbro include Las

Posas, Boomer, and Auld. They form ecological islands within more common substrates,

such as granodiorite, and support unique plant

communities including Cuyamaca and Tecate

cypress groves (Gordon and White 1994).

Several herbaceous plants are also endemic to

gabbro-derived soils, including two federally

listed species: San Diego thorn-mint

(Acanthomintha ilicifolia) and Mexican

flannelbush.

1981). Sampling after the most recent (i.e.,

1975 and 1976) fires showed that stands at

least fifty-two years old at the time of a fire

produced a greater number of seedlings per

pre-burn tree, and that these stands reestablished at densities several times higher than

pre-fire densities (Zedler 1981). Conversely,

stands thirty-three years old or younger at the

time of a fire established fewer seedlings than

there were mature trees before the fire and experienced significant decreases in stand

densities.

Mining activities have also adversely affected Tecate cypress in the assessment area.

Strip mining of underlying clay deposits destroyed some groves on private lands in the

Sierra Peak/Coal Canyon area of the Santa Ana

Mountains (Esser 1994a).

A species management guide for Tecate

cypress was developed by the Cleveland National Forest that summarizes approaches to

fire management and provides guidelines for

the use of fire in enhancing cypress stands on

the forest (Winter 1991a). The Guatay Mountain occurrence is proposed for designation as

a Research Natural Area (RNA). An estimated

64,000 trees occur at this site (Winter 1991a).

A large portion of the Coal Canyon population (540 acres) was recently purchased by the

CDFG and designated as an ecological reserve.

Two federally listed plants, Braunton’s

milk-vetch (Astragalus brauntonii) and Mexican flannelbush (Fremontodendron

mexicanum), are found with Tecate cypress.

Larvae of the rare Thorn’s hairstreak butterfly
49

Chapter 2

Figure 2.30. Rocky gabbro soil and chaparral at

King Creek, Cleveland National Forest. The soil is

rich in iron and recognized by its reddish color. MOZE

MOSSAY

four of the southern California national forests (fig. 2.31) (fig 2.32). The habitat type

covers an estimated 55,446 acres in southern

California, 38 percent (21,070 acres) occurring on public lands.

Meadows can be characterized as wet, dry,

or alkaline but are usually mesic, even in late

summer. Due to rainfall patterns they tend to

occur at lower elevations in the northern parts

of California and shift to higher elevations in

the southern areas of the state (Holland 1986).

Two physical conditions characterize meadows: 1) a shallow water table usually within

two feet of the soil surface in mid-summer and

2) surface soil material that is fine-textured

(i.e., a clay) and richly organic (Wood 1975).

Meadow soils are poorly draining relative to

the coarser soils of adjacent forest vegetation

(Holland 1986).

Meadows tend to form where there are

gentle gradients and relatively impervious bedrock occurring in combination with

appropriately sized upstream drainage basins.

Where basins are large and produce high volumes of water, fine soil materials are washed

away, preventing the establishment of meadow

habitat. Stable meadows are those with shallow slopes and smaller drainage basins where

fine materials are allowed to accumulate.

Meadows that occur narrowly along streams

and creeks are referred to as “stringer meadows.” Meadows often form on or in close

proximity to fault zones. The availability of

subsurface waters may be locally increased by

these subterranean impoundments (H. Gordon, Remote Sensing Lab, in litt. 1998).

A mix of hardwood and conifer species

typically encompasses meadows at lower elevations. At higher elevations the surrounding

forest shifts to mixed conifer and fir species.

Jeffrey pine, white fir, incense-cedar, and black

oak are frequent components of surrounding

vegetation in the mountains of San Diego

County (Winter 1991b). Montane meadows

are dominated floristically by sedges and

rushes, with perennial herbs and grasses also

well represented. Four federally listed plants,

San Bernardino blue grass (Poa atropurpurea),

bird-footed checkerbloom (Sidalcea pedata),

slender-petaled mustard (Thelypodium

stenopetalum), and California dandelion

(Taraxacum californicum), are found in

meadow habitat in the San Bernardino Mountains. The San Bernardino blue grass also

occurs in montane meadows within San Diego County.

A survey of sixty-two meadows on the

Cleveland, San Bernardino, and Angeles national forests and three state parks was

conducted in 1994 and 1995 (H. Gordon, Remote Sensing Lab, unpubl.data). Some of the

meadows sampled are shown in table 2.17.

The largest meadows in the assessment

area are found in the mountains of San Diego

County, but the majority of these are located

on private lands (e.g., Cuyamaca, Mendenhall,

French, and Dyche meadows). Other expansive
50

Figure 2.31. The distribution of montane meadows in southern California.

meadow systems are found in the San Jacinto

Mountains, with the largest located in Garner Valley. There are many meadows in the

San Bernardino Mountains, but most are small

in size. The San Gabriel Mountains contain very

few meadows due to their steep topography, although Big Pines Meadow is significant as the

primary location for the San Gabriel Mountains

blue butterfly (Plejebus saepiolus aureolus). In the

Castaic region, Knapp Ranch Meadow is estimated to cover almost two hundred acres.

Montane meadows on the Los Padres

National Forest include Toad Springs, Thorn,

and Chula Vista meadows, Yellow Jacket Creek

(a series of stringer meadows), and several unnamed meadows near Lockwood, Grade, and

Cuddy valleys, Mount Abel, and the San

Emigdio Mesa area (J. O’Hare, Angeles NF,

in litt. 1998).

All meadow habitats are sensitive to activities and disturbances that affect stability

of the surface soil, especially during the winter and spring when the ground is most

saturated. Meadow systems, particularly those

on steeper slopes, can develop gullies in response to disturbance. The best examples of

this are associated with road and trail systems

that increase the amount of runoff a meadow

receives and cause soil erosion. Eroded areas

convey water at a higher rate, eventually leading to the formation of gullies, which in turn
51

Chapter 2

Figure 2.32. Montane meadow habitat at Bluff Lake,

adjacent to the San Bernardino National Forest. An

endangered plant, the bird-footed checkerbloom, is

found here. LYNN LOZIER

channel water away from the meadow, effectively lowering the water table and removing

increasing amounts of topsoil (J. O’Hare,

Angeles NF, in litt. 1998; M. Bearmar, Cleveland NF, pers. comm.).

When the water table of a meadow is lowered, it allows for the steady encroachment and

establishment of nonmeadow flora. Runoff

from road and trail systems appears to be one

of the greatest impacts to meadow habitats

within the assessment area. Recurrent trampling by livestock, vehicles, or people can also

introduce soil erosion and cause gullying. Over

time gully systems may become stabilized and

form riparian habitat, much like what has occurred at Knapp Ranch on the Angeles

National Forest and Thorne Meadow on the

Los Padres National Forest (J. O’Hare, Angeles NF, in litt. 1998). The plains appear as distinct open patches

within forest and woodland vegetation often

dominated by Jeffrey pine, pinyon, and juniper species (fig. 2.34). Remnants of a huge

ice-age lake bottom (Krantz 1983), the plains

are part of the Mohave crustal block uplifted

during Quaternary time (Derby and Wilson

1979). They are treeless, deep clay deposits

that support a rare assemblage of plants reminiscent of an alpine flora. This flora consists

of small cushion-forming plants, tiny annuals, grasses, and succulents. The plants are all

well spaced, low growing, and sun tolerant,

yet exact floral composition varies between

sites. The substrate consists of clay soil (up to

Many montane meadows on national forest system lands have historically been

impacted by the overgrazing of livestock

(Krantz 1983; M. Borchert, Los Padres NF,

pers. comm; J. O’Hare, Angeles NF, pers.

comm.). Excessive grazing is believed to shift

floral composition from native perennials to

non-native annual species (Winter 1991b) and

the current trend on national forest system

lands has been to reduce the number of cattle

in these areas or remove them completely from

especially sensitive locations. However, the invasion of alien taxa appears to be a greater

problem in lower elevation meadows rather

than at higher elevations, where the habitat

seems to be in better condition overall (R.

Minnich, UC Riverside, in litt. 1998).

The Cleveland National Forest has developed a habitat management guide for four

sensitive plants that grow in riparian montane

meadows: Cuyamaca larkspur (Delphinium

hesperium ssp. cuyamacae), lemon lily (Lilium

parryi), Parish’s meadowfoam (Limnanthes gracilis var. parishi) and San Bernardino blue grass

(Winter 1991b).

Pebble Plains

Pebble plains have a very limited distribution in the northeastern San Bernardino

Mountains, occurring between elevations of

6,000 and 7,500 feet. They are found only

within a 92-square-mile area near the city of

Big Bear, on the San Bernardino National

Forest and on adjacent private lands (fig 2.33)

(Neel and Barrows 1990). Some well-known

sites include the Big Bear Lake complex, the

Sawmill complex, Gold Mountain, North

Baldwin Lake, Arrastre Flat/Union Flat,

Holcomb Valley, south Baldwin Ridge/Erwin

Lake, Onyx Ridge/Broom Flat, and Coxey

Meadow. Three hundred and seventy-nine

acres of pebble plain habitat are mapped in

our GIS database, 60 percent located on public lands. The Pebble Plain Habitat

Management Guide and Action Plan cites 546

acres of pebble plain habitat with 94 percent

occurring on public lands (Neel and Barrows

1990).
Table 2.17. A partial list of montane meadows on the Cleveland, San Bernardino, and Angeles national

forests and Palomar Mountain State Park. The assessment of meadow condition is based on notes taken by H.

Gordon during her field surveys in 1994 and 1995. Acreages reported are visual estimates.

Meadow Name Water Source Date of Assessment of Meadow

 Sampling Characteristics and Condition

Cleveland NF

Guatay runoff from Guatay Mtn. 5/95 upper area type converted?, drainage

channel, structures; 10-50 acres

Laguna Big and Little Laguna 7/95 some erosion in the channeled area of

lakes, Boiling Springs, the check dam, Prado area has cattle;

Escondido, Chico, and 500-600 acres

Los Rasalies ravines,

Agua Dulce Creek

Lost Valley Caliente Creek, spring 5/95 horses, portion of meadow in private

ownership, dispersed camping; 50-100

acres

Love Valley upland runoff 7/94 50-100 acres

Mendenhall Iron Springs Creek 6/95 historic and recent cattle grazing; 100-

200 acres

Organ Valley spring-fed 6/95 RNA for Engelmann oak; 5-10 acres

Roberts Ranch upland runoff 5/95 gullies caused by runoff from I-8, cattle,

recent acquisition; 100-200 acres

Tenaja upland runoff, springs 5/95 type conversion from chaparral? 100-

200 acres

San Bernardino NF

Baldy Mountain unknown 7/95 jeep trail, horse-holding structures,

cattle, adjacent to fire break; 50-100

acres

Big Meadow Santa Ana River 8/95 lower portion of meadow affected by

upstream gullying, the encroachment of

Great Basin sagebrush, and non-native

species; 50-100 acres

Broom Flat Arrastre Creek, runoff 7/95 cattle; 50-100 acres

Coxey springs, Coxey Creek 8/95 non-native species in northern area of

meadow; 10-50 acres

Garner Valley South Fork of San 7/95 some soil erosion, cattle; >300 acres

Jacinto River

Holcomb Valley Holcomb and Caribou 8/95 historic gold mining and ranching in the

creeks Belleville area; 50-100 acres

South Fork South Fork of Santa 9/95 irrigation ditch in upper meadow area;

Ana River 10-50 acres

Tahquitz Tahquitz Creek 9/95 Jeffrey pine encroaching on lower

meadow, trail; 10-50 acres

Angeles NF

Big Pines seasonal Mescal Creek 6/95 wet meadow easily accessible, retreating

system due to expansion of Mountain High Ski

area parking lots, presence of San

Gabriel Mtns. blue butterfly; <5 acres

Brown’s Flat overland flow 6/95 in the San Dimas Experimental Forest;

50-100 acres

Knapp Ranch seasonal Castaic Crk system 5/95 100-200 acres

Palomar State Park

Lower French French Creek 5/95 some channelization, adjacent forest

burned

Upper Doane Doane Creek 6/95 not grazed regularly since 1940s, some

erosion, small channel; 50-100 acres
53

Chapter 2

53 percent) mixed with quartzite pebbles and

gravel that are continually pushed to the surface through frost action (Holland 1986; Neel

and Barrows 1990). The combination of clay

soil, frost heaving, extreme annual and daily

temperature fluctuations, high light intensity,

and dessicating winds is thought to prevent

the establishment of tree species onto the

plains (Derby and Wilson 1979). Three federally listed plants, Big Bear Valley sandwort

(Arenaria ursina), ash-gray Indian paintbrush

(Castilleja cinerea), and southern mountain

buckwheat (Eriogonum kennedyi var.

austromontanum), are found on pebble plains.

Figure 2.33. Occurrences of pebble plains and carbonate outcrops in the eastern San Bernardino Mountains.

An estimated 150 acres of pebble plain

habitat are believed to have been lost by creation of the Big Bear Lake reservoir in the

1800s. More recently the habitat has declined

in amount and quality primarily from vehicle

activity on the sites (Neel and Barrows 1990).

Some pebble plains have been completely

devegetated (e.g., upper Sugarloaf). The habitat is especially vulnerable to damage from

vehicles when the ground is saturated. Deep

ruts are created in the soil that directly affect

the vegetation and alter the surface hydrology

of the plains.

The Pebble Plain Habitat Management

Guide and Action Plan was developed by the

San Bernardino National Forest to provide

management direction for long-term conservation of pebble plains and the rare plants
54

assocated with them. Closure of unauthorized

vehicle routes through pebble plain habitat (including walk-throughs that discourage

motorcycle access and barriers to prevent vehicle access), signage, increased patrol, mineral

withdrawal, habitat acquisition, removal of

non-native grasses, and public education are

actions being taken to protect and enhance

the habitat. Conserving pebble plain habitat

over a broad geographic range, reducing

fragmention, and encouraging compatible uses

are Forest Service goals for this habitat.

Limestone/Carbonate Outcrops

Carbonate outcrops are found along the

desert-facing slopes of the San Bernardino

Mountains. Located mainly within the San

Bernardino National Forest, these soil deposits extend for approximately twenty miles

along an east-west axis and occupy an estimated 21,000 acres. Over 18,000 acres of these

unique soils are within the assessment area, of

which 87 percent are on public lands (fig.

2.33). Disjunct outcrops occur just south of

Sugarlump Ridge and to the east as far as the

Sawtooth Hills (USFWS 1997b). The U.S.

Fish and Wildlife Service Draft Recovery Plan

reports a higher amount of total carbonate

habitat (32,620 acres) though subsurface deposits may account for the additional acres

(USFWS 1997b).

Figure 2.35. Carbonate habitat north of Holcomb

Valley in the San Bernardino Mountains. A lowgrowing plant, the endangered cushenbury

buckwheat, can be seen in the foreground. TIM KRANTZ

High-grade carbonate deposits in the San

Bernardino Mountains are mined for commercial use; the carbonate in these mountains

is one of just three high-quality deposits in

the western United States (Krantz 1983,

1990). Limestone is used in a number of commercial applications and almost all of the

habitat on public land is under mining claims.

Mining activities such as the direct removal

of soil, road development, and dumping of

overburden rock, have led to an overall decline in the amount and quality of carbonate

habitat. Plant communitites associated with

this habitat are slow to recover from disturbance due to the low productivity, thin soils,

and very dry climate on the desert side of these

mountains (Rowlands 1980).

The high levels of ground disturbance associated with mining, the potential for

additional claims to become active, and insufficient protection mechanisms necessitated

Figure 2.34. Pebble plain habitat at Gold Mountain,

San Bernardino National Forest. Plants in this habitat

type are diminutive and alpine-like. Despite their

appearance, pebble plains have high floral diversity.

MAILE NEEL

Carbonate is named for its primary constituent, calcium carbonate. The substrate is

an alkaline, sedimentary rock type that weathers into limestone and dolomite soils. A

number of plants are endemic to these carbonate soils (see carbonate plant group,

chapter 5). On a broader scale, carbonate outcrops support desert montane plant

communities such as blackbush scrub, pinyonjuniper woodlands, Jeffrey pine-western

juniper woodlands, and Joshua tree woodlands

(USFWS 1997b) (fig. 2.35).
55

Chapter 2

the federal listing in 1994 of five rare plants

endemic to carbonate (Neel 1997). This law

created a rare situation where two very prominent laws (the 1872 Mining Law and the 1973

Endangered Species Act) appear to conflict

with one another.

To resolve this issue, a collaborative effort

has been initiated among the San Bernardino

National Forest, the Bureau of Land Management, the U.S. Fish and Wildlife Service, mine

operators, researchers, and other affected parties, to design a reserve system for these plants

and their habitat (G. Zimmerman, San Bernardino NF, in litt. 1998). The Carbonate

Endemic Plant Conservation Strategy is being designed to incorporate many large

occurrences of the five listed plants over a wide

range of habitat mosaics throughout their geographic ranges. Buffers to minimize conflicts

and to ensure defensible areas, connections

between populations and habitats, and inclusion of sites that contain more than one listed

species are other important elements being

considered in the reserve design. Genetic research through patterns of isozyme variation

(Neel 1997), results of soil sampling, and a

detailed vegetation classification combined

with field studies of individual plant occurrences are being completed and will provide

information necessary for the reserve design.

GIS coverages of plant locations, carbonate

rock locations, proposed and approved future

mining activities, land use conflicts, and other

resource values have been developed in the

Conservation Study for Five Carbonate Plant

Species: a study of land use conflict in the San

Bernardino National Forest (USDA Forest Service 1996).

Serpentine Outcrops

Serpentinite rock outcrops occur within

the assessment area in the Santa Lucia Ranges,

the southern Los Padres region, and at one

locality in the Santa Ana Mountains. Within

the boundaries of the Los Padres Natonal Forest are an estimated 31,470 acres of

serpentinite-derived soil (fig. 2.36).

This soil, commonly called serpentine, is

recognized by its waxy texture and colors that

range from green to blue to red. Generally high

in magnesium (consisting mainly of hydrated

magnesium silicate) and low in calcium, nitrogen, and phosphorous, the soil is considered

impoverished and supports only those plants

adapted to or tolerant of its unique chemistry. It contains varying amounts of heavy

metals (e.g., cobalt, nickel, and iron) that contribute to its color (J. O’Hare, Angeles NF,

pers. comm.).

In its favor, serpentine often has a higher

water-holding capacity than adjacent soils (i.e.,

it forms clay soils). Grassland, chaparral, oak

woodland, and conifer forest may all form on

a serpentine substrate, but species richness and

density is always much lower than on adjacent nonserpentine soils (Kruckeberg 1984).

Extreme serpentine habitats are referred to as

“barrens” because they support little or no

vegetation. Less toxic sites can support up to

215 species and varieties of plants and at least

nine species and subspecies of butterflies

(Schoenherr 1992). Sargent cypress and

knobcone pine are reliable indicators of a serpentine soil. Twelve of the plant species

addressed in this assessment are indicators of

or endemic to serpentine soils. Of these, ten are

classified by the regional forester as forest service

sensitive on the Los Padres National Forest (see

serpentine plant group in chapter 5).

The Cachuma Saddle area and Figueroa

Mountain, both in the San Rafael Range, contain serpentine chaparral and woodland,

including groves of Sargent cypress. Serpentine woodland and Sargent cypress occur again

at Cuesta Pass and West Cuesta Ridge in the

southern Santa Lucia Range. Further north,

the Chew’s Ridge area in the Santa Lucia

Ranges contains good examples of serpentine

grassland and woodland. Serpentine grassland

is also found in the Pine Ridge area of the Santa

Lucia Ranges (Kruckeberg 1984).

Serpentine is an indicator of economic

metals; quicksilver (mercury), chromium,

nickel, magnesite, asbestos, talc, soapstone,

and jadeite are all found in association with

serpentine and other ultramafic outcrops. A

number of historic and active mines occur in
56

Three substantial groves occur on the forest at Zaca and Alder peaks and in the Cuesta

Ridge Botanical Area (fig. 2.38). At least six

additional sites are also located in the Santa

Lucia Ranges (D. Wilken, Santa Barbara

Botanic Garden, in litt. 1998).The grove at

Cuesta Ridge in the southern Santa Lucias is

the southernmost large occurrence and one of

several isolated groves ranging from northern

Mendocino County south to Zaca Peak in

Figure 2.36. The distribution of serpentine outcrops on the Los Padres National Forest.

the Santa Lucia Ranges and potential exists

for mining activities to adversely impact serpentine habitat on the forest (Kruckeberg

1984).

Sargent Cypress Groves

Sargent cypress (Cupressus sargentii) groves

are scattered within the assessment area in the

Santa Lucia Ranges and southern Los Padres

region. Groves are distributed from 650 to

3,300 feet elevation. The species is considered

the most wide-ranging cypress in California

(fig. 2.37). Based on Clare Hardham’s mapping effort, an estimated 1,585 acres of Sargent

cypress habitat occur in central and southern

California, with 74 percent located on public

lands (Hardham 1962). A small amount is

found on U.S. Army Fort Hunter Liggett

Military Reservation and 880 acres are reported on the Los Padres National Forest (Los

Padres NF 1988a).
57

Chapter 2

Figure 2.37. The distribution of Santa Lucia fir forest and Sargent cypress groves in central and southern

California.

Santa Barbara County. The Zaca Peak site, located near the San Rafael Wilderness Area, is

much smaller than the occurrence at Cuesta

Ridge (Jenkins 1981). In the Santa Lucia

Ranges, the majority of groves are located

along the main ridgeline at about 2,500 feet.

The tree may be more prevalent at these sites

due to heavy fog occurrence (Hardham 1962).

Sargent cypress is also located along a ridge

formed by the King City Fault near Bryson

and at lower elevations in the Los Burros Creek

drainage.

Sargent cypress is an indicator of serpentine soils and tends to occur with other

sensitive plant species (Los Padres NF 1988a).

Factors other than soil affect the distribution

of Sargent cypress, however, as it occupies less

than three percent of serpentine habitat on the

forest. The tree grows on rocky slopes, ridges,

and raised stream benches and terraces (Sawyer and Keeler-Wolf 1995). Throughout most

of its range Sargent cypress occurs with gray

pine, Coulter pine, scrub oak, leather oak, and

buck brush (Johnston 1994). It also frequently

grows with California bay, interior live oak,

and knobcone pine. Muir’s hairstreak butterfly is strongly allied with Sargent cypress.

Like other cypress, Sargent is adapted to

and dependent on fire for seed dispersal and

enhancement of germination. Fires that are
58

Occurrences range from a low point at

Big Sur Gorge to the top of Cone Peak but

greater than half of the fir’s distribution is

above 3,200 feet (Talley 1974). The southernmost stands occur at lower elevations in

San Luis Obispo County. These stands are

found along coastal drainages sometimes

adjacent to redwood (Sequoia sempervirens).

Occupied drainages include Marmolejo

Creek, Jackson Creek, the Big Sur River, the

west and main forks of Limekiln Creek,

Hare Canyon, and Villa Creek. The species

is also found along north- and east-flowing

drainages including the Carmel River, Miller

Fork, Anastasia Canyon, Church Creek, Zig

Zag Creek, Higgins Creek, the Arroyo Seco

River, the San Antonio River, the Negro

Fork of Nacimiento River, and San Miguel

Creek.

Based on physical characteristics of the

sites it occupies (rocky areas with low fuel

loads), Santa Lucia fir is generally regarded as

intolerant of fire, yet some mature stands have

survived wildland fires (J. Kwasny, Los Padres

NF, pers. comm.). Talley looked at the fire

history of Santa Lucia fir and determined that

there were few differences between past and

present fire intensities within stands, despite

changing fire regimes in California overall. Fire

suppression activities such as fire lines and

scale map of all known Santa Lucia fir stands

(Talley 1974). Based on this map there are an

estimated 7,576 acres of Santa Lucia fir forest, with 95 percent located on public lands.

The Los Padres Forest Plan however, cites

1,400 acres of Santa Lucia fir within the forest boundary (Los Padres NF 1988).

Stands occur in relatively inaccessible areas: on steep north- or east-facing slopes, along

ridges, in canyon bottoms, and on raised

stream benches and terraces (fig. 2.39) (Sawyer and Keeler-Wolf 1995). The tree may be

dominant in stands or co-dominant with canyon live oak. At lower elevations it occupies

the same habitats as coast live oak, Pacific

madrone, and coast redwood. At higher elevations it grows with tan oak, interior live

oak, and incense-cedar (Johnston 1994).

Figure 2.38. Sargent cypress and chaparral growing

on serpentine soil at Cuesta Ridge Botanical Area,

Los Padres National Forest. MALCOLM MCLEOD

too frequent, however, prevent adequate seed

production and can extirpate entire groves

(Esser 1994b). South of an existing Waterdog

Creek grove, a cypress “swamp” is believed to

have been extirpated by fires in 1953 and 1960

(Hardham 1962). The tree has a low-branching habit that makes it susceptible to crown

fire and is often killed in wildfires. Required

fire-free time intervals are not well defined for

the species but might be consistent with other

cypress in California (Esser 1994b).

Sargent cypress is generally not considered

a rare tree and has no legal status. However,

because it is localized on serpentine soil and

because some groves, particularly on the

Monterey Ranger District, have been reduced

in size by short fire-return intervals, Sargent

cypress communities are considered rare on

forest system lands (M. Borchert, Los Padres

NF, pers. comm.).

Santa Lucia Fir Forest

Santa Lucia fir (Abies bracteata), also

known as bristlecone fir, is found in the northern Santa Lucia Mountains of Monterey

County. The tree is narrowly distributed in

an area about thirteen miles wide and fiftyfive miles long in the Ventana Wildernes area

of the Los Padres National Forest and a portion of U.S. Army Fort Hunter Liggett,

bordering the forest on the east (fig.

2.37)(Schoenherr 1992). As part of his

master’s thesis, Steve Talley produced a coarse-
59

Chapter 2

fuelbreaks are not currently allowed in stands

on the Los Padres National Forest. Fire is not

prevented from burning through stands nor

is it directed toward stands.

Several naturalists, beginning with Sargent

in 1898, have recognized Santa Lucia fir as a

species at risk due to its narrow endemism and

susceptibility to cone parasites (Talley 1974).

Occurrences of Santa Lucia fir appear stable

at this time; however, a recently recognized

threat is the invasion of non-native species into

the understory. The rhizomatous shrub French

broom (Genista monspessulana) is particularly

invasive and difficult to eradicate once established. It directly competes with seedlings of

Santa Lucia fir and other native understory

species (J. Kwasny, Los Padres NF, pers.

comm.)

Figure 2.39. A stand of Santa Lucia fir at Cone Peak,

Monterey Ranger District, Los Padres National Forest.

JEFF KWASNY

Disjunct (Locally Rare)

Communities

Two disjunct plant communities were

identified in the assessment area. These communities are relatively common in other areas,

but are rare or highly localized within the assessment area. They are briefly described

below.

Aspen Groves

Quaking aspen (Populus tremuloides) is a

wide-ranging tree in North America, but its

distribution is patchy in the Californias. It is

widespread in the Sierra Nevada and there are

substantial stands in the White Mountains and

in Baja California’s Sierra San Pedro Martir.

However, aspen is essentially absent in the

southern California mountains with the exception of two small groves in the San

Bernardino Mountains: one on Fish Creek in

the San Gorgonio Wilderness Area and the

other on upper Arrastre Creek (Thorne 1977).

These two occurrences combined cover less

than fifty acres, all of which are located on

national forest system land. A third grove, reportedly mapped in 1935 by D. Axelrod, may

still exist west of Lake Arrowhead (Jones

1989). The groves are found on decomposed

granite at the bottom of canyons and on slopes

along creeks.

The Arrastre Creek aspen grove occurs

along a seasonal watercourse. It is found

mainly with xeric plants (i.e., sagebrush scrub,

pinyon, Jeffrey pine forest) and endures a dry

summer climate. Aerial photographs from

1972 and 1983 indicate that the grove is decreasing in size (Jones 1989). The Fish Creek

aspen grove also occurs along a drainage in

what is otherwise a Jeffrey pine and subalpine

forest. Beavers were introduced into the habitat and subsequently reduced this grove by an

estimated 25 to 50 percent (Jones 1989).

Evidence indicates that the tree was once

more common in the mountain ranges of

southern California and migrated into northern Baja during prehistoric times (Oberbauer

1986). Aspen is a clonal organism and the San

Bernardino Mountain populations were
60

Figure 2.40. Knobcone pine near Cuyama Grade,

Los Padres National Forest. JANET NICKERMAN

analyzed and found to be almost genetically

identical to each other (Zona 1989).

Knobcone Pine Stands

Disjunct stands of knobcone pine (Pinus

attenuata) occur naturally in the assessment

area at just a few locations: in the northern

Santa Lucia Range of Monterey County, in

San Luis Obispo County at Cuesta Pass, in

the western San Bernardino Mountains, and

in the Santa Ana Mountains (Vogl et al. 1977).

There are approximately 1,233 acres of

knobcone pine habitat mapped at these locations, 85 percent of which is located on public

lands. The species is more common throughout northern California and also grows near

Ensenada, Mexico.

Knobcone pine has been reported from

sea level to over 5,500 feet, though stands usually occupy a transitional zone between lower

chaparral/woodland and higher elevation conifer forest (Vogl et al. 1977). Talley and

Griffin (1980) and Griffin (1982) report on

the fire ecology of knobcone pine in the northern Santa Lucia Range. Similar to Coulter

pine, knobcone pine has serotinous cones and

is dependent on fire for seed dispersal (Vogl

1976).

In the San Bernardino Mountains, stands

of knobcone pine cover approximately 990

acres between City Creek and Government

Canyon. In the Santa Ana Mountains, small

stands of this pine occur in otherwise chaparral-dominated areas on the slopes of Sugarloaf,

Pleasants, and Santiago peaks (Thorne 1977;

F. Roberts, USFWS, pers. comm.). The stand

at Pleasants Peak grows on serpentine soils (EA

Engineering, Science, and Technology 1995).

Usually restricted to dry, rocky sites with shallow soils, knobcone pine is typically associated

with infertile substrates that limit competition

from other conifers (Holland 1986) (fig. 2.40).