California State University, Northridge Vegetation Of

CALIFORNIA STATE UNIVERSITY, NORTHRIDGE

VEGETATION OF WILSON CANYON, I\ LOS ANGELES COUNTY, CALIFORNIA

A thesis submitted in partial satisfaction of the requirements for the degree of Master of Arts in

Geography

by Rodger Vance -Johnson

May, 1975 The thesis of Rodger Vance Johnson is approved:

California State University, Northridge

:.ray, 1975

ii DEDICATION

To Mom and Dad

iii ACKNOWLEDGEMENTS

Numerous contributions important to the progress and ultimate completion of this thesis were made by several individuals gracious enough to take the time and effort to do so. The writer would like to acknowledge and, at the same time, gratefully thank these people. First of all, special recognition is due two individ

uals: Dr. John F. Gaines, who first interested the writer in vegetation geography and who provided firm guidance throughout all phases of research and writing; and Sally Hooper, who illustrated Figure 8 and, more importantly, encouraged and affirmed the research endeavors of the writer. Many thanks to the following: Dr. Gary Lobb and Dr. Jean Pedersen for reading and editing of the manuscript; Dr. Ross Dick for his interest in the progress of this thesis and his suggestion and demonstration of the Point Centered Quarter Method; Mr. Marshall Chrostowski for a summer of experience, learning, and fun; Tom Gordon, Mike Grayurr", and Dr. Kenneth Wilson of the California State Uni versity, Northridge, Department of Biology, for assistance in identification of many species; and Greg Poseley of the California State University, Northridge, Department of Geography-Cartography Laboratory, for assistance in pre-

iv paration of the figures and for his excellent photographic work. The writer is indebted to Vern Tryon for aerial views of the study area and to Robert Hagen, a fellow graduate student, who spent numerous hours in the field to aid in transect measurements. Others taking time to go into the field include Greg Gaddis, Sandra Bierk, and the writers' brother, Forrest Johnson. Thanks to a number of individuals who offered timely advice, listened with a patient ear, or shared past experi ences of research and writing. These include: Jan Harwell, Gary Rees, Mike Taugher, Liisa Kald, and Laird Hendricks. Thanks also to Robert Provin and Larry Miyaki for their light-hearted banter--it really helped!

v TABLE OF CONTENTS

DEDICATION. . . • . • ...... • . iii

ACKNOWlEDGEMENTS ••..•....•.••.•...•. ~...... iv

LIST OF FIG URE_S .. I ••••••••••••••••••• I •••••••••••• viii

LIST OF TABLES ...... •...... ix

ABSTRACT . ...•...... II •••• I •••••••••••••••••••••••• X

Chapter

I . I!~TR ODUC TI ON. I ••••••••••••• I ••••••••• ·- •••••• 1

Objectives Location and Size Topography Geology Climate Vegetative Setting

II. fdETHODOLOGY ...... I •••••••••••••••••• ~ • • • • • • 19

Mapping of Vegetation Units Collection of Transect Data Preparation of the Final Map

III. PHYSIOGNOMIC TYPES AND ASSOCIATIONS.. . . . • . . . 39

Woodland Chaparral Sagebrush-Chaparral Sagebrush Mixed Lifeform Annual Grass Sparsely Vegetated Surfaces

IV. AREAL RELATIONSHIPS ...... • ...... 82 General Observations Specific Observations Summary

vi APPENDIX I. LIST OF SPECIES •••••••••••••••••••• 98

APPENDIX I I. ASSOCIATIONS AND COMPONENT STANDS •• 103

APPENDIX III. SUMMARIES OF TRANSECT DATA ••••••••• 116

BIBLIOGRAPHY CITED. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 120

vii FIGURES

1. Location of Wilson Canyon, Los Angeles County, California ...... •...... 6 2. Topography of Wilson Canyon, Los Angeles County, California ...... 8 3. Geology of Wilson Canyon ...... •.. 11 4. Monthly Temperature Regimes, 1957-1973, San Fernando, Calif0rnia ...... 13 5. Annual Precipitation, 1955-1973 ...... 15 6. Mean Monthly Precipitation, 1955-1972 ...... 15 ?. Illustration of Point Centered Quarter Method ...... ' ...... 29 8.' Diagram of a Line Intercept Showing Details of Intercept along one 15 foot Interval .. 32 9. Location of Transects ..•...... 33 10. Plant Associations of Wilson Canyon, Los Angeles County, California ...... ••. pocket

viii. TABLES

1. Physiognomic Types and Associations ...... 40 2. Occurrence and Relative Dominance of Species in Plant Associations in Wilson Canyon ......

ix ABSTRACT

VEGETATION OF WILSON CANYON, LOS ANGE.LES COUNTY, CALIFORNIA by Rodger Vance Johnson Master of Arts in Geography May, 1975 Differences in the floristic composition and physiog nomy of vegetation in montane southern California occur within small continuous areas and between areas widely sep arated by intervening mountain ranges and broad valleys.

An area of 2.52 square miles in Wilson Canyon in the west ern San Gabriel Mountains was studied to describe, record, and interpret variations in vegetation stands within a con tinuous area characterized by great variations in terrain. The objectives of this field study were: (1) to iden tify the species, (2) to map and describe the vegetation,

(3) ~o test the results of fi9ld mapping by quantitative measures of selected stands, (4) to record observable habi tat factors related to vegetative distributions, and (5) to attempt to account for observed vegetative-habitat relation-

X ships, especially affects of fire and cultural factors on vegetation.

Using a mapping and classifying system based on spe cies dominance, 355 stands were mapped and described; five categories of species dominance being recognized: dominants, co-dominants, associated dominants, subdominants, and asso ciated species. These stands were consolidated into 6 physiognomic types: Woodland, Chaparral, Sagebrush

Chaparral, Sagebrush, Mixed Lifeform, and Annual Grass.

One additional category was recognized--sparsely vegetated surfaces. Within the physiognomic types are 19 associations as follows: Woodland--Pinus coulteri, Pseudotsuga macrocarpa,

Quercus agrifolia-Q. chrysolepis, Salix spp.; Chaparral-

Arctostaphylos spp.-Ceanothus spp.-Quercus spp., Ceanothus crassifolius, C. crassifolius-Adenostema fasciculatum, A. fasciculatum, Cercocarpus betuloides, Eriodictyon crassifo lium-Heteromeles arbutifolia; Sagebrush-Chaparral--Ceano thus crassifolius-Salvia mellifera, Adenostema fasciculatum

Salvia mellifera, Ceanothus crassifolius-Adenostema fascicu latum-Salvia mellifera, Rhus laurina; Sagebrush--Salvia mellifera, ~· mellifera-Artemisia californica; Mixed Life form--Artemisia californica-Eriogonum fasciculatum-Annual grass, Adenostema fasciculatum-Eriodictyon crassifoliurll

Eriogonum fasciculatum-Annual grass; and Annual grass.

The slopes of Wilson Canyon are overwhelmingly domi nated by shrubby sclerophyllous vegetation varying consid-

xi erably in composition, height, and density. Chaparral domi nates upper canyon slopes generally above J,OOO feet and intergrades downslope into sagebrush-chaparral and sagebrush.

Woodlands dominated by broadleaf sclerophyllous live-oaks are restricted to narrow bands along streamcourses or form small groves within shrub-dominated areas on north-facing slopes and on areas of recent alluvium. The mixed lifeform type and annual grass dominate eastern portions of the can yon.

The major vegetative distributions appear to be related to the Mediterranean climatic regime of southern

California and to recurrent fires. With increasing altitude, increasing precipitation, and decreasing temperature, the vegetation increases in height, density, and in number of sclerophyllous, evergreen'species. Minor variations in vegetative distributions are related to variations in ter rain and geology.

Fire and cultural factors strongly affect the vegeta tion, resulting in its degeneration to seral forms, out right destruction, or replacement by weedy or introduced species,

xii CHAPTER I

INTRODUCTION

Vegetation mapping in California, especially southern

California, has been marked by periods of relative inactiv- ity and others of intense protracted effort.

Early mapping efforts of governmental agencies or individual researchers were largely piecemeal, focusing on specific areas for particular purposes. Maps of the forest reserves of southern California at scales of 1:321,000 and

1:352,000 were produced about the turn of the century by the United States Geological Survey. 1 In 1911, brushland areas of southern California were mapped at a scale of 2 1:2,700,000 by the United States Forest Service. Outside efforts of researchers such as Shantz, Cooper, and Shreve,3 produced vegetation maps of areas under study which were of large to medium scale, 1:32,000 to 1:200,000.

Not until the 1930's was an ambitious, comprehensive mapping program initiated. The Vegetative Type Map Survey of the United States Forest Service under the supervision of A.E. Wieslander, originally intending to map all the vegetation of California and part of Nevada, succeeded in mapping nearly forty million acres.4 During a fifteen year period the Vegetative Type Map Survey produced maps at

1 2

scales cf 1:62,500 and 1:125,000 which provided a record of major vegetative types and subtypes defined by dominant species. For example, on the Vegetation Type Map of the

San Fernando Quadrangle, 1:62.500, miscellaneous, shrub, and woodland types were delimited. Shrubs were subdivided into subtypes of sagebrush, chamise-chaparral, chaparral, and desert chaparral; woodlands into juniper, bigcone spruce, and live-oak; miscellaneous into barren, semi-barren, grassland, and cultivated. Dominants of these subtypes were indicated directly on the map by letter symbols.

The maps and accompanying literature of the Vegeta tive Type Map Survey were useful for a variety of purposes.

The maps provided base line data for evaluating potential timber utilization, watershed value, recreational uses, and potential fire hazard of the various vegetative types mapped, ~.g., fire hazard distinctions were made between semi-desert chaparral and chaparral, the former of lesser fire hazard because of lesser density. These maps also provide historical vegetative records useful in assessing changes in the plant cover.

Application of the large scale maps of the Vegetative

Type Map Survey for research and management purposes is presently met by three obvious limitations.

(1) Though adequate in portraying broad vegetative patterns as related to habitats, and useful in affording glimpses of the flora of an area, the maps of the Vegeta tive Type Map Survey are limited by the scales used. J ) \_ Areas mapped at the scales of 1:62,500 and 1:125,000 orig-

inally contained vegetation patterns and floristic compos-

ition much more varied and diverse than recorded map data

indicate. Because of the limitations of scale, the maps do

not reveal much of the intricate vegetative patterns and

diverse floristic composition of an area--details which can

. be displayed on larger scale maps and which are potentially

more useful in studying interrelationships of vegetation

with other physical and cultural phenomena. (2) At present the maps of the Vegetative Type Map

Survey are no longer available in quantities to warrant

their use by various researchers or agencies.

(J) The maps of the Vegetative Type Map Survey are

inadequate for vegetative-land resource management purposes

because of changes in the vegetative cover resulting from

land use, natural undisturbed succession, and fire.

To the writer's knowledge, the only large scale maps

of the San Gabriel Mountains are those of the Vegetative

Type Map Survey produced more than three decades ago,

though later efforts have produced maps at small scales in

excess of 1:2,JOO,OOO portraying the vegetation of the San

Gabriel Mountains and other portions of California inbroad

categories.5

Increasing emphasis upo11 the conservation of dwin-

dling resources in the coming years will require up-to-date

detailed vegetation maps of areas such as the San Gabriel

Mountains to plan adequately for the utilization of vegeta- 4

tive resources in as rational a manner as possible. Map data obtained today and in the future can be compared with that of forty years ago to provide useful measures of vegetative change.

Objectives

Wilson Canyon, the area selected for this study, is representative of many locales in montane southern Cali fornia. Within a relatively small area Wilson Canyon exhib its differences in floristic composition and physiognomy attributable to physical and cultural factors. Climate, topography, and lithology interacted to produce a variety of habitats to which plant cover responded, resulting in diverse vegetative patterning. Plant cover was further affected by other factors, especially repeated fires, which drastically altered or destroyed previous vegetative pat terns or induced patterns which effectively mask the effects of other habitat factors.

Most of Wilson Canyon is under the supervision of the

United States Forest Service but certain parcels in the southern end of the canyon are either in private control or are managed by the Los Angeles County Flood Control Dis trict. Implementation of management decisions of the above agencies or actions of indivi0uals affect the vegetative cover in significant ways, whether through clearance pro grams for fire suppression, construction and maintenance of roads and debris dams, or for economic utilization. 5

Specific objectives of this study were designed to provide base line vegetative data for one small portion of the San Gabriel Mountains on a map ofmuch larger scale than those of the Vegetative Type Iviap Survey which W01J.ld be useful for effective, planning of vegetative-land resources and which would contribute to an understanding of the interrelationships of vegetation and habitat. In future years the data provided by this study may be of value in appraising changes in the plant cover. The specific objectives of this study were: (1) to map and describe the vegetation of Wilson Canyon, (2) to test the effectiveness of field mapping by quantitative sampling of selected vegetatj_ve stands, (J) to provide an appraisal of as wide a range of species as possible, (4) to record observable habitat factors as related to vegetative distributions and to attempt to account for some of the ob served habitat-vegetation relationships, and (5) to eval uate the role of fire and cultural phenomena in altering vegetative patterns.

Location and Size

Wilson Canyon is located 22 miles north of the Los

Angeles Civic Center at approximately 34°20' North latitude and t18°27' West longitude(Figure 1). Wilson Canyon is bounded on the south by populus San Fernando Valley and on the north by the crest of the Bear Mountain Divide, a western extension of the San Gabriel Mountains. Lying predomi- 6

LOCATION OF WILSON CANYON, LOS ANGELES COUNTY, CALIFORNIA

0 5 Miles t Scale 1:250,000 N 7

nantly within the western Tujunga District, Angeles Nation- al Forest, the canyon is 2.52 square miles in area.

Topography

Wilson Canyon is similar to many other drainagebasins on the south side of the San Gabriel Mountains, consisting of numerous narrow, steep walled, deeply incised smaller canyons and ravines issuing abruptly onto relatively level, flanking alluvial fans. Steep slopes interrupted by cliff scarps together with narrow, rock strewn ridges produce a predominantly rugged, mountainous relief(Figure 2).

Steep mountainous terrain is interrupted by a relatively flat upland in the west-central portion of the study area at an elevation of approximately 2600 feet. The upland is level to irregular, punctuated at intervals by intermittent stream beds and sandstone outcrops. Because of the decrease in gradient, streams issuing onto the upland deposit alluvial material; those exiting onto abruptly steepening terrain downslope incise the margins of the upland into V-shaped ravines. South of Hospital Fault

(Figure J) however, the relief abruptly lessens, ridges become more subdued, and watercourses merge into relatively wide, flat bottomed, alluvial-filled valleys carved from clastic sediments. Total relief in the canyon is nearly 2J88 feet with the lowest elevation of 1560 feet located at the canyon outlet and the highest elevation of 3948 feet located in FIGURE 2 TOPOGRAPHY OF WILSON CANYON / LOS ANGELES COUN1Y, CALIFORNIA

t N

Scale 1 :24,000

0 Y. Mile

Contour Interval 40 Feet

OJ 9

the extreme northeastern corner of the canyon. These two points are 9400 feet apart, resulting in a gradient of 25.4 percent, or equivalent to a rise of approximately 1J42 feet per mile.

Geology The lense shaped mountain mass into which Wilson

Canyon is carved is in a geologically active aiea which experienced intermittent and frequent uplift during the

Cenozoic Era.6 The study area is near the epicenter of the

1971 San Fernando Earthquake which produced heavy damage in nearby communities of Sylmar, San Fernando, Newhall, and

Saugus, and resulted in substantial vertical displacement.

Numerous slip scarps which resulted from the quake are vis ible in the study area.

The San Gabriel Fault Zone of right lateral strike slip faulting is located a few miles northward. The Sierra

Madre Fault Zone, a series of discontinuous reverse faults, of which Hospital Fault is part, bounds this mountain mass on the south.

Seven lithologic units in the study area range from unconsolidated recent sediments near the canyon outlet to pre-Tertiary crystalline-metamorphic basement rocks. A westward extension of the plutonic massif of the San Gabri el Mountains, represented by a complex mixture of granite gneisses, underlies at least 80 percent of the study area north of Hospital Fault. Masses of granodiorite composed 10 of gray, medium to coarse grained granitic rocks and close ly related quartz diorite predominate towards the northern and eastern rims of the study area.7 South and west are areas underlain by diorite gneiss composed of metamorphics including dark gneisses, metadiorites, massive hornblende . 8 diorite, amphibole, and biotite schlst. A dotted line across the upper portion of the study area(Figure 3) delin eates the contact of these interdigitating rock types. Two remnant exposures of the Placerita Formation, a metasedimentary rock composed predominantly of crystalline limestone and dolomite overlie diorite gneiss in the far eastern portion of the canyon.9 Lower Pliocene sediments coincide with the upland described earlier in the western portion of the canyon.

Named the Elsmere Member of the Repetto Formation, this unit lies unconformably upon diorite gneiss and is bounded on the north and west by an inferred fault. The Elsmere

Member is composed of interbedded marine fossiliferous sed iments including pebble conglomerate, coarse to very fine sandstone, siltstone, silty shale, and well stratified arkose.10 As will be seen later, this formation coincides closely, but not exclusively, with the Adenostema fascicu- ---latum-Salvia mellifera Association South of Hospital Fault lies the Pacoima Formation, a strongly folded sedimentary deposit of poorly sorted fan- glomerate or sedimentary breccia laid down in middle to early upper Pleistocene time. The Pacoima formation is FIGURE 3 GEOLOGY OF WILSON CANYON

Scale 1:24,000

Explanation ~ Alluvium [§!] Terrace Deposits

[§E] Pacoima Formation ~ E I smere Member ~ Granodiorite ~Cl Diorite Gneiss ~ Placerita Formation Symbols

-- -- Inferred Contact Well Defined Fault Inferred Fault ---- Strike and Dip ~ Foliation Source: G. B. Oakshott, Fernando

p p 12

sharply delimited along the Hospital Fault from adjoining diorite gneiss which thrusts southward ever the formation at angles of 45 to 60 degrees,11 Quaternary terrace depos its composed of poorly consolidated unsorted detritus over lie the Pacoima Formation in two places, forming distinct terraces.

Recent sediments occur in several stream valleys near the southern outlet of the canyon, behind earth catchment basins, or at 11 nickpoints" along upper drainages. In ad dition, significant amounts of stream deposited material are found on the upland previously described. Alluvial deposits in all areas consist of predominantly coarse ac cumulations of boulders, gravels, and sand of varying thick ness.

Climate

Wilson Canyon lies within the summer dry-subtropical or Mediterranean climatic regime of coastal southern

California and experiences warm, dry summers and cool, moist winters.

The nearest temperature data available are from San Fernando, California at an elevation of 965 feet, 500 feet lower than the lowest elevation of Wilson Canyon, and a little more than 2 miles distant. Temperature data are shown in Figure 4. Mean annual temperature is 6J.JOF,

Highest mean maximum monthly temperatures for July and

August are 76.1°F and 77.0°F, respectively; lowest minimum 1J

115,------~~==~~----~~~------y 110 100

80 ! ..:) D .70 Q. E II 1- 60

so Mean Minimum

Absolute Minimum 30

May Jun Jul Aug Sep Oct FIGURE 4.-MONTHLY TEMPERATURE REGIMES, 1957·1973 SAN FERNANDO, CALIFORNIA

Source: U.S. Weather Bureau Climatolo ical Data Volumes 61•78. 14

monthly temperatures for December and January are 45.1°F and 44.JOF, respectively. Highest absolute temperature recorded is 1140F; the lowest is 27°F. Since no reliable temperature data are available from Wilson Canyon, one might expect temperatures at elevations equivalent to those of the study area to be from 2 to 10 degrees lower. Precipitation data are available from two stations maintained by the Flood Control District at Wilson Canyon, one at an elevation of 1425 feet just outside the canyon outlet, the other at an elevation of 3175 feet near the northern canyon rim. Data in Figures 5 and 6 are computed and listed for a hydrologic year, October through September. At Station A, the higher station, the mean annual precipi tation for an 18 year period (1955-1972) is 24.1", with a high of 46.7" and a low of 10.J". At Station B, the lower station, the mean annual precipitation for the same 18 year period is 18.9", with a high of J4.8" and a low of 9.0". As shown by Figure 5, the annual precipitation varies con siderably from year to year. In all of the years of record more rainfall was received at the higher station than at the lower. Average monthly precipitation is portrayed in Figure 5. Approximately 90 percent of all precipitation is received during the cool months of November through April and is mostly in the form of rain, though infrequent snow fall does occur at the highest elevations during the winter months. 15

50 --Station A@ 3175' 45 ---Station 8@ 1425'

..e .s:. 35 u ..: c 30 c .i0 ~ 25 ·ua. , ! D. 20 I I 15 I

55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 Year FIGURE 5.·-ANNUAL PRECIPITATION, 1955·1973

6~------r --Station A@ 3175' ---Station 8@ 1425'

VI e 4 .s:. u ..: c

Jan Feb Mar Apr May Jun J u I Sep 0 ct Nov Dec

FIGURE 6.·aMEAN MONTHLY PRECIPITATION, 1955~1972

Source: Los Angeles County Flood Control District 16

Vegetative Setting

The vegetation of Wilson Canyon is comprised of four basic types characteristic of the Upper Sonoran Life Zone of California, 12 including live-oak woodlands, chaparral, sagebrush, and annual grass, as well as mixtures of sagebrush-chaparral, and a mixed lifeform type of shrubs, subshrubs, and annual grass.

The diversity of vegetation in Wilson Canyon, with four basic physiognomic types and 33 species assigned some degree of dominance is perhaps surprising, considering the small size of the canyon--2.52 square miles. One hundred and eighteen species, representing 48 botanical families, were collected and identified during the course of this study. The classification scheme used in this study further elaborates the diversity of basic types and is presented in

Chapter III. 17

NOTES

1uni ted States Geological Survey, "San Jacinto Forest Reserves Showing Distribution of Species," 1:352,000, in The San Jacinto Forest Reserve, by J.B. Leiberg, Annual Report No. 20 ( 1898-1899), pt. 5, following p. 4 56; "San Bernardino Forest Reserves Showing Distribution of Species," 1:321,000, in The San Bernardino Forest Reserve, by J.B. Leiberg, Annual Report No. 20 (1898-1899), following p. 450.

2united States Department of Agriculture, "Chaparral Regions of Southern California," 1:2,700,000, in Chaparral Studies in the Dwarf Forest, or Elfemvood of Southern California, by C. Plummer, Forest Service Bulletin No. 85 (1911), facing p. 48.

3H.L. Shantz, "Map Showing the Plant Communities in Coachella Valley," 1:318,000, in "Indicator Significance of the Natural Vegetation of the Southwestern Desert Regions," Journal of Agricultural Research 28 (1924): 728; W.S. Cooper, "Distribution of the Two Oaks, Valley Oak (Quercus lobata) and Coast Live Oak (Quercus agrifolia)," 1:200,000, in "Vegetational Development upon Alluvial Fans in the Vicinity of Palo Alto, California," Ecology 7 (1926): 7; F. Shreve, "Map Showing Distribution of Types of Vegetation in a Representative Area of the Santa Lucia Mountains, 12 Miles South of Carmel," 1:32,500, in "The Vegetation of a Coastal Mountain Range," Ecology 8 (1927): 42.

4united States Forest Service, Pacific Southwest Forest and Range Experiment Station, Profiles of California Vegetation, by William B. Critchfield, Research Paper PSW- 76 (Washington, D.C.: United States Government Printing Office, 1971), p. 1.

5Herbert A. Jensen, "Vegetation Types of California," 1:2,400,000, in "A System for Classifying Vegetation in California," California Fish and Game 33 (1947): facing p. 200.

6California Department of Natural Resources, Division of Mines, Geology and Mineral Deposits of San Fernando Quadrangle, Los An eles Count , California, by Gordon B. Oakeshott, Bulletin 172 San Francisco, 1958), p. 89.

7rbid. , p. 54. 18

Br bid. , p. 52 . 9rbid. , p. 51 . lorbid., p. 77. 11rbid., p. 86. 12w. Jepson, A Manual of the Flowering Plants of California (Oakland: Goodhue Printing Co., 1923), p. 6. CHAPTER II

METHODOLOGY

. / ) Three distinct phases in the mapping and description of the vegetation of Wilson Canyon were: (1) mapping of vegetation units in the field, (b) collection of transect data, and (c) preparation of the final map.

Mapping of Vegetation Units The field map resulted from the recognition and delimitation of vegetative units based on subjective evalua tions of selected vegetative criteria. The procedures necessary to prepare for and to produce this map were: (1) identification of species, (2) selection of criteria for the recognition of units to be mapped in the field, (3) determination of a minimal mappable field unit, (4) the preparation of a base map, (5) field observations, and (6) delimitation of vegetative boundaries on the field map.

Identification of Species Identification of species proceeded in an initial phase in which certain obvious dominant species were iden-

------tified during their periods o~ inflorescence prior to field mapping and a continuing phase throughout the entire period of field mapping as newly recognized dominant and other less important species came into flower. 1 The initial

19 20

phase was essential to provide adequate knowledge for map-

ping to commence; the'latter to fill gaps in information in

earlier mapping and to enrich the description of vegetative

·units. 2 Species recognized early as important but which

were not identified at that time were labeled tentatively

as unknowns. When subsequently identified, their labels

were replaced by their respective identifications.3

Criterion for the Recognition of Field Units v/

The criterion for the recognition of units mappable

in the field was species dominance which was subjectively

estimated by combining two physiognomic characters, height

and coverage, and a sociologic character, numerical abun-

dance.

Dominant species are ecological successes, so preval-

ent in a stand of vegetation that they suppress or reduce

the numbers and vitality of other species by effectively

controlling the local enviroP~ental conditions under which 4 the latter must live. The obvious dominants of any stand

are of greatest height, most extensive coverage, and great-

est abundance. However in grasslands and some types of

savannas herbaceous grasses dominate the upper stratum or

may be areally dominant in a lower stratum if exceeded 1n

height by shrubby or arboreal species which are less sig

nificant areally.

Mapping vegetation on the basis of species dominance

was particularly suitable for Wilson Canyon. (1) The criterion of dominance is representative of observable, lim

ited vegetative characters, i.e., height, coverage, and

abundance. (2) Subjective evaluation of ·these characters

allows for relatively rapid description and mapping of

field units in a variety of terrain. (3) The criterion of dominance may be consistently applied to all field units by

the use of clearly defined descriptions reflecting degrees

of dominance which provide data suitable for comparisons of floristic differences between field units. (4) The cri terion of dominance requires a botanical knowledge suffi

cient to identify dominant species in a vegetative unit.

_Not all species present need be identified, especially

those which are insignificant for mapping purposes. Thus

an exhaustive, time-consuming identification of the entire

flora of the numerous habitats in a study area is not nec

essary.

A vegetative analysis of species dominance is inter mediate to that of a detailed floristic analysis emphasiz ing identification of all species in a vegetative unit, and a simplified physiognomic, descriptive analysis utilizing little, if any, floristic criteria. A detailed floristic analysis defines vegetative units by all floristic members, regardless of the status of each member within the unit, i.~.. , floristic criteria may emphasize small, herbaceous indicator species which are non-essential from the stand point of dominance. Purely physiognomic criteria differ from dominance criteria because the former criteria define 22

vegetative units by physical attributes, ~.g., height,

layering~ coverage, and so on, little emphasis being placed

on identification of component species. Application of the

criterion of dominance requires the identification of vege

tative units by species that are preeminent because of

height, coverage, and abundance, i.~., species which

visually characterize a unit.

Determination of a Minimal Mappable Field Unit

Vegetative field units, hereafter referred to as

Stands, were determined in the field on the basis of one or

more dominant species. A stand was the smallest concrete

·unit of vegetation recognized, each stand being composed of

vegetative segments more closely resembling one another in

composition and growthform than those of adjacent stands.

The minimal mappable area of the stand recognized in

the field was determined by the scale of the base map. At

1:5,500 most of the stands whose smallest dimension on the

map was less than one-eight inch were not recorded because

the map space delimited was inadequate for the writing of

2 or 3 numbers necessary to make appropriate entrees on the

base map. Exceptions were long linear stands, ~.g., Rhus

laurina stands which because of their distinctive growth

form in comparison with that of neighboring stands were

difficult to ignore and small stands on steep slopes which

planimetrically were small but were too visually signifi-

cant to be ignored. 2J

Preparation of a Base.Map A base map at an approximate scale of 1:5,500 was prepared on an enlarged overlay of an aerial photograph of Wilson Canyon at an average scale of 1:22,000. Ridge and valley lines were transferred to the overlay to facilitate location of boundaries of stands. The resultant base map, approximately 2 by 2 feet, was cut into four sections for field use. Topographic distortions resulting from varia tions in terrain, photographic tilt, and outward displace ment on the photograph were corrected later.

Field Observations Field observations were made intermittently from September 1973 until completion of mapping of the entire drainage basin of Wilson Canyon in July 1974. During field observations each stand was numbered, described, and re corded, two types of field observations being taken: (1) description of the vegetative stands based on the domi nance of species, and (2) observations on visual aspects of habitats of the stands.

Descriptions Based On Dominance As previously indicated, each stand was recognized by the criterion of dominance. Five categories of speciJs dominance used in this research were: (1) dominant species or dominants; single species which occupied at least 50 percent of a stand. (2) co-dominants; two or more species 24 which in combined area occupied at least 65 percent of a stand. (J) associated.dominants; important elements of a stand, locally conspicuous, but not of sufficient areal coverage or abundance to be regarded as dominants. r.ollec tively associated dominants commonly occupied the majority of the area not occupied by dominants. (4) subdominants: species which dominated lower strata and were recognized only in obviously stratified communities such as woodlands. Recognition of stratification in shrubby areas was not necessary for mapping purposes and would have been too time consuming to determine. Subdominants were as abundant relatively in their strata as dominants of the upper strata. (5) assaciated species: species present in a stand but occupying relative small portion thereof, each species individually occupying less than 5 percent of a stand. Vegetative descriptions were recorded by a stratified formula as follows:

Dominants or Co-dominants - -Associated Dominants Subdominants -- Associated-Species-

In stands where subdominants or associated species were not recognized, a zero was recorded in the appropriate stratum of the formula. Most of the species were listed by the first letter of .the genus and the first letter of the specific epithet of their scientific names. If two plants had the same 25

,first letter symbols, the first letter of the genus and the

~first and second lett~rs of the specific epithet of these-

cond species were recorded, e.g., Arctostaphylos glauca as

Ag, ~rctostaphylos glandulosa having been recorded as Agl.

In one instance the first and second letters of the genus

and the first letter symbols of the specific epithet were

:used to clearly distinguish one species from another, e.g.,

Paeonia californica as Pc, Polypodium californicum as Pea,

and Pinus coulteri as Pic.

Observations of Habitats of Stands

Observations on various habitat factors for each

stand included some or all of the following; slope angle;

slope aspect; presence of rock types, e.g., crystalline or

sedimentary; faulting patterns; gullying or slip scars;

presence of cultural disturbances such as landfill, road-

cuts, and debris basins; and presence of introduced species,

~.g., Nicotiana glauca. A general description of the stand

including height and density were recorded along with loca

tion of the stand. Examples of stands described are as

follows. Species have been indicated by scientific name in

examples (1) through (J) below. In actual field work, the

symbols in Appendix I were used.

( 1) Stand Ac Sm Artemisia californica 70% coverage. #24 -Af Ef- Eriogonuni fasciculatum locally co11spic __o __ uous near roadside. Nicotiana glauca Mv Ng Rl on outwash area of sandy substrate. Sm Yw Height of stand 3 feet except emergent Rhus laurina. Stand merges into #2~ as Adenostema fasciculatum coverage increases. 26

~-·-·------·-·------····------·-·. ·--·- ·-·····-·· .. ----·····-·-·-···· ··-·---·----·--··--·--- ' (2) Stand Qa Discontinuous oak woodland with #119 - ijcli - arboreal-like Ceanothus oliganthus Elc Gr and Heteromeles arbutifolia. Af-Ag Ccr Cb-Cl Other shrubs lightly scattered as Co Ha Jc Ll Pi understory; annual grasses(Gr) and Qd Ri Td Rl Sm Elymus condensatus subdominant, Uc Yw providing dense, complete cover.

( 3) Stand Stand on conglomerate-sandstone-- #20a .along ridgelines and cliff-like 0 margins. Average height of stand Agl Ccr Ec-Eco is 3 feet. Agl to 6 feet, espe~ Gr Ha Ls Rl Sd cially on rocky outcrops. Absence Sm Tl of Ccr as dominant or associated dominant noteworthy.

Delimitation of Vegetative Boundaries.Q.!::! the Field Map

i Sketching from major vantage points, ~.g., roads, I ridges, and hilltops, stands were delimited and numbered on

the base map. Problems encountered in field mapping were:

: (1) observations of limits of stands, (2) field decisions

on the representation of transitional and interdigitating

stands, and (3) field decisions on areas composed of a

mosaic of small distinct stands.

Observations of Limits of Stands

Individual stands were often delimited from several

vantage points because their boundaries were not always

visible from the observation point from which they were

initially recognized and described. Obtaining vantage

points to determine the boundaries of some stands involved

:with accuracy the boundaries of some stands as other stands L~=-~=--~~=-~ch_=~-~~-t-~---~-~~:_:__~-~~~~~---~~=~-·-···------·--·------~ 27

Transitional and Interdigitating Stands Areas of transition or interdigitation between clearly defined stands were either combined to form a separate stand, or an arbitrary boundary was drawn through these areas where the vegetational gradient was judged to cross from one stand to the next.

Small Distinct Stands Areas significantly larger than the minimal mappable area which were composed of many reasonably distinct stands, many of which were smaller than a minimal mappable area were treated in either of two ways: (a) the area was divid ed into smaller stands if these stands were sharply dif- ferentiated from each other and exceeded the minimal mappable area. The smaller the area mapped, the more distinctive were its dominant species and growthform compared with those of adjacent stands. (b) the area was mapped as one stand in which the relative abundance of dominant species and growthform were recorded. No attempt was made to map the component stands which were smaller than the minimal mappable area.

- Collection of Transect Data

Quantitative sampling of stands was used to test the effectiveness of field mapping. Because of the time re- \ quired to conduct these tests all individual stands delim- 28

ited on the map were not tested. A representation of diverse types was included by Sfu~pling the fol+owing stands: 125, 164, 128, and 15 by the Point Centered Quarter Method 'and 25, 29a, 29, and 28 by the Line Intercept Method. The location and nQ~ber of each transect is shown on Figure 9 and tabulated results are listed in Appendix III. The methods utilized were the Point Centered Quarter· Method and the Line Intercept Method.5

The Point Centered Quarter Method The Point Centered Quarter Method, as employed in this research, consisted of the establishment of quadrants (quarters) at points spaced at intervals of 25 feet along an azimuth which was the greatest diagonal within the sam pled stand, the initial observation point being established 10 feet from the point at which the azimuth was determined. Quadrants were demarcated by a line perpendicular to the transect line(see Figure 7) and were numbered and recorded clockwise. For each quadrant the three plants near- ' est the observation point were recorded by species. The height of the nearest individual and its distance from the observation point were also recorded. Only shrubs with exposed canopies were recorded, all plants of shorter stature being juvenile or subdominant. Additional notes on other species in the area, clinometer readings from point to point, and gullies or other marked terrain irregularities were recorded. This procedure was repeated for each succeeding A. Po;ni1 + + + + + +

B. I 2 0 Figure 7. Illustration of Point Centered Quarter Method A. Observation points at 25 foot intervals along a selected azimuth 0 CJ from Point 1. The first observation point was located 10 feet from Point 1. 0 ~ B. Planimetric view of an observation point. For each quadrant the o, C0 three plants nearest an observation point were recorded by species. 0 0 The height of the nearest individual and its distance from the o· observation point were also recorded. 4 I 3

N \0 30

point, the number of points proportional to the length of the diagonal. Individuals of a species which exhibited stump i sprouting were counted only once although individual stems arising from a common root platform were present in different quadrants and separated by as much as 3 feet of intervening stump material and soil. Only the largest stem was recorded regardless of the number and position of other stems arising from the root platform. Difficulties in determining with precision the limits of root platforms may have resulted in some instances in a biased sampling favor- ' . . ing the count of stump sprouters, l.~., dlfferent stems of one individual may have been confused with and recorded as separate individuals, and in other instances of favoring non-stump sprouting species. Analysis of vegetative data following field sampling yielded measures of the relative abundance of individual species in a stand, the relative frequency of the most important species, the average height of all individuals sam-

pled along the transect, and the area density, i.~., the number of individuals of all species per unit area. 6 Application of the Point Centered Quarter Method to selected stands substantiated the use of subjective evalua tion of dominance in the preparation of the field map. 31

The Line Intercept Method The Line Intercept Method consisted in the measure ment of the vertical intercept of the tallest growthform projected onto a tape stretched over the vegetation of a stand(Figure 8). The line intercept azimuth was carefully established beforehand to avoid landslips or cliffs which were common in the stands measured. The length of intercept qf each shrub, its scientific name, and the total intercept distance were recorded for alternating 15 foot sections. By measuring only alternat ing sections the total length of line intercept was "stretched" over a larger distance resulting in sampling of a larger variety of vegetation. All herbaceous species were grouped within the category "grasses". Barren areas were also recorded. Slope angles, terrain irregularities, and notes on species present in sampled stands but not intercepted were recorded. Measures of absolute coverage, relative abundance, and relative frequency? were obtained by analysis following field sampling. Accounting for 2 of the 3 qualities of dominance, 1·£·, coverage and numerical abundance, results of limited sampling confirmed field estimates of species domi~ance in the preparation ~f the field map. A B c D E F G H ·----- ~-----~- ~------~--1

Figure 8. Diagram of a Line Intercept Showing Details of Intercept Along One 15 foot Interval, D-E.

Measurements of plant intercepts were taken along alternate 15 foot segments on a selected azimuth. Measured 15 foot segments indicated by solid line. Azimuth determined at point A. First measured intercept initiated at Point B, ten feet from point A.

\..;.) !'\) 33

CIO 0 N z gf Cl It) CIO It) N ~ q- cO 'J) z N Ol ~ <{ N t;; ..n 8 N Ol z b 0 w ~ q-" a: 0 N ::::> ~ l!) f-4 ~ u:: 0 < ell"' z I- u w q- It) ~ en N M z ~ <{ a: I- 34

Preparation of the Final Map

One glance at the completed field map containing 355 stands made it obvious that a reader could grasp the 5ross distribution of plant associations only with difficulty. To ameliorate this situation, the detailed field map was transformed to a generalized final map(Figure 10) by the determination of associations and physiognomic types and by the construction of the final map.

Determination of Associations and Physiognomic Types Two levels of classification, associations and physiognomic types, each level portraying larger spatial affinities of the vegetation, were established by abstrac tion of the concrete stands in the following manner. The data on each stand in the field notebook were placed on individual cards to facilitate sorting into ten tative groupings. Thirty-three dominant, co-dominant, and associated dominant species were used to describe all 355 stands. Stands of similar dominant or co-dominant species were consolidated into 19 larger units, designated as Associations which were named according to their dominant or co-dominant species. Of the 19 associations recognized, 8 were named for one species, 6 for 2 species, one for 3 species, and 4 for more than 3 species. For the sake of brevity, the generic names Arctostaphylos-Ceanothus-Quercus 35 were used to name an association of 6 co-dominant species of the above genera. 'The generic name Salix was used in naming one other association. Areas without significant vegetative cover were recorded as sparsely vegetated; species on these surfaces were largely ephemeral.

Because vegetation varies almost infinitely, several stands did not fit precisely into any one of the 19 associa tions which had to be recognized because of the frequent reoccurrence of areas with similar dominant and co-dominant species. Each of these remaining stands was placed within the association which it most closely resembled in composi tion and growthform. Thus some stands do not fit precisely the description of associations as represented in Table 2.

A stand placed in an association because of its general similarity to other stands of that association may contain a stand dominant which is not listed as an association domi nant.

Associations were consolidated to form Physiognomic

Types defined by growthform and leaf texture. These are woodland(arboreal), chaparral(hardleaf shrub), sagebrush chaparral(softleaf-hardleaf shrub), sagebrush(softleaf shrub), mixed lifeform(hardleaf-softleaf shrub, softleaf subshrub, annual grass), and herbaceous(annual grass).

Construction of the Final Map

Construction of the final map proceeded as follows.

On a copy of the field map individual stand numbers were replaced by the number of their respective associations into which they had been classified. Associations were then transferred to an overlay on a topographic base map en~arged from 1:24,000 to 1:8,500 to correct distortion on the original field map. One zip-a-tone pattern common to each physiognomic type was oriented in different compass directions to repre sent each component association. Beginning with the dark~ est pattern to represent woodland, zip-a-tone patterns became progressively lighter for successive physiognomic types, i.e., chaparral, sagebrush-chaparral, and so on. 37

NOTES

1Beecher Cramptons' Grasses of California was partic ularly helpful in identifying perennial and annual grasses. Howard McMinns' An Illustrated Manual of California Shrubs aided in the identification of several important shrubs, The texts of greatest importance were the floras of Phillip Munz, A Flora of Southern California and A California Flora and Supplement, which provided the most up-to-date nomen clatural revisions generally available.

2The identification of approximately 118 species, listed in Appendix I, resulted from the interest of the writer in obtaining as thorough a knowledge possible of the floristics of Wilson Canyon. This was made possible by course work undertaken in Systematic Botany. 3A herbarium has been prepared and is available in the Geography Department of California State University, Northridge. 4s.A. Cain & G.M. Castro, Manual of Vegetation Analysis (New York: Harper and Brothers., 1959), p. 30.

5G, Cottam & J.T. Curtis, "The Use of Distance Mea sures in Phytosociological Sampling," Ecology 37 (1956): 451-460; R.H. Canfield, "Application of the Line Intercep tion Method in Sampling Range Vegetation," Journal of For estry 39 (1941): )88-394. 6G. Cottam, J.T. Curtis, & B.W. Hale, "Some Sampling Characteristics of a Population of Randomly Dispersed In dividuals," Ecology 34 (1953): 741-757. Relative abundance is used in lieu of relative density, which the above writers define as the "number of individuals of the species" divided by the "number of individuals of all species", this value then multiplied by 100 to obtain a percentage. Relative abundance has been suggeated by Dr. Ross Dick (Professor of Geography, University of Queensland, Brisbane, Australia), because the value obtained is a percentage measure of the total number of individuals oi a species present, not ~ density value as the original term, relative density, im plies; Relative frequency is the "number of points of occur rence of a species" divided by the "number of points of occurrence of all species", this value then multiplied by 100 to obtain a percentage; Area density is calculated per acre as follows: 38

where: 43560 square feet equals one acre and "d" equals average distance of all shrubs to the center point. 7Absolute cover is calculated as follows: the "-t:otal cover of a species'' divided by the "total cover of all species", this value then multiplied by 100 to obtain a percentage. Absolute cover may be established assuming that the proportion of line intercepted by a species is propor tional to its actual coverage; the term relative abundance was substituted for relative density because the value obtained is not a true density value and the use of the latter term is misleading; relative frequency is calculated as follows: the "number of line sections in which a species occurs" divided by the "number of line sections in which any species occurs", this value then multiplied by 100 to obtain a percentage. CHAPTER III

PHYSIOGNOMIC TYPES AND ASSOCIATIONS

Physiognomic types and associations established for

Wilson Canyon are outlined in Table 1. The distribution of

plant associations are shown on Figure 10 as mapp~d from September 1973 to July 1974. Some areas were cleared by the United States Forest Service subsequent to mapping, but resultant changes have not been recorded. In particular,

some areas recorded as sparsely vegetated are now develop ing herbaceous growth of annual grass and forbs, occasional

subshrubs ,. and resprouts of chaparral shrubs. As previously stated in chapter 1, there are 4 basic physiognomic types in Wilson Canyon, i.e., woodland, chapar- . -- ral, sagebrush, and annual grass. These types were elabo- rated into two additional categories: (1) sagebrush-chaparral in which sagebrush and chaparral species are mixed, and (2) mixed lifeforrn in which annual grass, chaparral, and sagebrush, or both, are mixed. Areas without significant vegetated cover were mapped as sparsely vegetated surfaces. Within each physiognomic type, except sparsely vegetated surfaces, are one or more associations defined and nam~d by dominant species, co-dominant species, or by dominant genera. Each association has been described in this

39 40

TABLE 1

PHYSIOGNOMIC TYPES AND ASSOCIATIONS

Physiognomic ~ Association A. Woodland 1 . Pinus coulteri 2. Pseudotsuga macrocarpa 3 .. Quercus agrifolia- Q. chrysolepis 4. Salix spp. B. Chaparral 5. Arctostaphylos spp.-Cean othus spp. -Quer.cus spp. 6. Ceanothus crassifolius 7. Ceanothus crassifolius- Adenostema fas~iculatum 8. Adenostema fasciculatum 9. Cercocarpus betuloides 10. Eriodictyon crassifolium Heteromeles arbutifolia c. Sagebrush-Chaparral 11. Ceanothus crassifolius Salvia mell1fera 12. Adenostema fasciculatum Salvia mellifera 13. Adenostema fasciculatum Ceanothus crassifolius Salvia mellifera 14. Rhus laurina D. Sagebrush 15. Salvia mellifera 16. Salvia mellifera Artemisia californica E. Mixed Lifeform 17. Artemisia calif6rnica Eriogonum fasciculatum Annual grass 18. Adenostema fasciculatum Eriodictyon crassifolium Eriogonum fasciculatum Annual grass F. Annual Grass 19. Annual grass G. Sparsely Vegetated Surfaces

j . 41

chapter.

Woodlands Woodlands, occupying small parts of the study area, are scattered throughout the canyon, many in isolated clumps too small to map, but forming significant stands along watercourses, on north-facing slopes, and on deep alluvial soils at canyon outlets. The four woodland associations are: (1) Pinus coulteri, (2) Pseudotsuga macrocarpa, (J) Quercus agrifolia-Q. chrysolepis, and (4) Salix spp.

Pinus coulteri Association A small woodland of young coulter pine (Pinus coul teri) was planted by the United States Forest Service in the northeast portion of the canyon in a slightly bowl-shaped depression at an elevation of approximately 3500 feet. Surrounding chaparral stands were cleared for at least 200 feet to provide protection from fire. Most of the trees are less than 20 feet tall, appear to be thriving, and provide a coverage in excess of 80 percent. Shrub species, mostly stump sprouters, include chamise (Adenostema fasciculatum), * Eastwood. manzanita (Arctostaphylos glandulosa), mountain mahogany (Cercocarpus betuloides), and scrub interior live oak (Quercus wislizenii var. frutescens). *Each species is listed initially by common and sci entific name; all subsequent references are by scientific name only. Common and scientific names of all species mentioned in this report are listed in Appendix I. 42

These widely scattered shrubs provide little ground cover and display the effects of recently sprayed herbicides to retard their growth. Prominent herbaceous species are annual grasses such as slender oat (Avena barbata), redbrome (Bromus rubens), ripgut grass (Bromus diandrus), and hare barley (Hordeum leporinum) and a ligneous forb, Penstemon grinellii.

Pseudotsuga macrocarpa Association Two stands dominated by bigcone spruce (Pseudotsuga macrocarpa) occur on steep, mostly barren, deeply eroded north-facing slopes, most of which exceed 35 degrees. Big cone spruce trees, 80 to 100 feet tall, form an open, dis continuous canopy. These trees grow out of solid rock, their roots twisting into crevices to provide anchorage in a granitic substrate. Fire scars of dead and blackened branches and charred bark mar many of the trees. Associated dominant tree species of coast live-oak (Quercus agrifolia), canyon live-oak (Q. chrysolepis), and sycamore (Platanus racemosa) are lower in stature. Associated shrub species clinging to rock are widely scattered and nowhere form a continuous cover. Among these are Cercocarpus betuloides, hoaryleaf ceanothus (Ceanothus crassifolius), hairy ceanothus (Q. oliganthus), toyon (Heteromeles arbutifolia), thickleaf yerba santa (Eriodic tyon crassifolium), Adenostema fasciculatum, laurel sumac (Rhus laurina), and black sage (Salvia mellifera). Rosettes of two succulent live-forever (Dudleya)

species cling to rock'walls. Poison sumac (Toxicodendron

diversilobum) lianas with stem diameters of one to 2 inches

climb as high as 50 feet up the trunks of bigcone spruce. Herbaceous cover of annual grass is confined to small

facets containing accumulations of soil. Stands of bigcone

spruce merge downslope into live-oak dominated stands along

the canyon bottoms.

Quercus agrifolia-Q. chrysolepis Association

Quercus agrifolia and Q. chrysolepis dominate the

largest, most extensive, and most variable woodland associ

ation. Best developed along streamsides at the bottom of

canyons and ravines, stands of this association also occur

at seepage points where differing lithologies are in con

tact and on north-facing slopes.

Though named for two broadleaf evergreen sclerophyl

lous trees, this association also contains broadleaf deci

duous tree species including white alder (Alnus rhombifolia),

bigleaf maple (Acer macrophyllum), California Walnut

(Juglans californica), and Fremont cottonwood (Populus fre montii) as prominent associated dominants or as associated species, especially along watercourses where water is avail able throughout the year.

California laurel (Umbellularia californica), another broadleaf sclerophyll, is confined almost completely to shady streamside locations where it occurs as an important 44

associated dominant in one stand. Tree heights range from 15 feet on steep, south facing slopes to 50 feet where trees 20 to JO feet apart form park-like stands on deep alluvial soil. Coverage ranges from open to closed, the openness of some stands re sulting from repeated burning, with live growth restricted to the central trunks of trees, their lateral branches hav ing been burnt and fallen. Subdominant lifeforms and associated species are ex tremely variable from stand to stand but the following types were recognized: (1) annual grasses understory, (2) mixed lifeform understory, (J) shrub understory, and (4) riparian understory.

Annual Grasses Understory An understory dominated by annual grasses including Avena barbata, Bromus rubens, and Bromus diandrus is common in several stands. Shrubs and subshrubs, uncommon in such stands, usually appear only on the margins. Other herbaceous species interspersed among the annual grasses are the ferns polypody (Polypodium californicum) and bracken (Pteridium aquilinum), giant wild rye (Elymus condensatus), lupine (Lupinus latifolius), miners' lettuce (Claytonia perfoliata), and wallflower (Erysimum capitatum), all being common on sites of nearly continuous water seep age. Wild mustard (Brassica geniculata) and filaree (Ero dium ciculatium) are common annuals in drier portions of 45

these stands.

Mixed Lifeform Understory Several stands contain an understory of shrubs, sub shrubs, and annual grasses in1;ermixed in varying amoun·Gs. For example, one stand displays 5 distinct subcanopy types. In sunny locations between constituent oaks, annual grass dominates the substratum; herbaceous subshrubs including horehound (Marrubium vulgare), chaparral nightshade (Sola

~ xanti), and Toxicodendron diversilobum form distinct substrata, the first species occurring in shady sites. Periwinkle (Vinca major), an escape, forms dense mats 2 feet in height. Preferring shady locations, this species appears to be expanding into Toxicodendron diversilobum, Marrubium vulgare, and Solanum xanti. Along margins of this woodland, Heteromeles arbutifolia, redberry (Rhamnus ilicifolia), and Rhus laurina form dense subdominant strata 10 feet in height. In other portions of this woodland the ground layer is covered by a dense leaf litter with little shrubby or herbaceous growth. In one stand is a variable understory dominated by an extremely dense mat-like growth of thorny blackberry (Rubus sp.) amid which are patches of annual grass and Toxicodendron diversilobum. 46

Shrub Understory In woodlands adjacent to chaparral, the understory is comprised of a dense growth of shrubs with very little her baceous growth. This subcanopy merges with surrounding chaparral as the dominant arboreal canopy disappears.

Riparian Understory Riparian species in areas of yearlong water supply including seep willow (Baccharis glutinosa), willow (Salix spp.), and Artemisia douglasiana form conspicuous subdomi nant shrub canopies restricted to stream beds beneath wood-. land stands. Associated species in this and succeeding associa tions are numerous but are not all listed in the text. They are listed in Table 2 along with dominant, associated dominant, and subdominant species of each association.

Salix ~· Association The Salix association occurs in riparian habitats where a plentiful water supply is available yearlong. Sandwiched between live-oak woodlands, Salix stands are gallery-like and attain heights of 20 feet. Quercus agri folia, Platanus racemosa, and Populus fremontii are pre sent, but infrequent, occurring as outliers of adjacent woodlands. Baccharis glutinosa and Artemisia douglasiana form a dense undergrowth scarcely passable except along estab- sa,oads paonpoJlUI 1 sa,oads palepossv v sa,oads lUeu!wopqns ... sa,oads lueu,woa pale!oossv o sa,oads lUeu!woa e

V_l V_l_ V w n .J o lJ!i""i'iluo~ 1ii1l [fl.1[ilo? .J 3 VlV"fe wn1vzn~1~sv VI V 1e1 0 I 0 I 0 I 0 IV I 0 I 0 IV IV I 0 J 0 J 0 J 0 J V J J V J J tllnflo]?ssv.J~ uol.P?P 0 ?.J3 VI VI IV I I I I I I I I I I I I I I I I I vnoJ?u?t~vn/~':l:."ilJJ',?~;J;J3 vlvlvlvl I lvl jVIVIVI_•Iolvlolvl lvlv v sapfofnfat[S'iid.Jv~o~.Ja;) v v vI v v OTOTv o • v v jouvaJ VIOivl I I lvlvlvlvlvlolololel lvl 1 1 s?wlapo.>naz sn'l1ouvaJ v I o I vI v I o I o I e I o I e I v I o I 0 I el e I o I I vI vI I -nr'!10JfrfliJ-:JSfiT(fOuv a :r v t151tllO)Jlbj V~Pfi1! v •dss s1.JV7n??"J''&1'f3ljJ!J~ VIVI lVI I lVI I I I I I I I I 1•1•1 I I vsolf)Tnzlis?.JV'I~~vg

:1v1•1•1vlvl: v VI I I lVI lVI lVI IVIOIOIOIOIIvl TvTnsoznpuvzll sozTi{ifVjSOj:j.JV v lei vI 0 I 0( vieT. ro rv ro Jerel 51 6T lvl I vI W1ljvzn~?:JSV] VW<>jsouapv ~ 0 v~?u.Joj?Zv~ vpvtnzzaqwlJ I s u aJ]aJ :iCTwa-s n·? ofi"lia s v VIV VI IVIV e1o SJdazosl..J'I~ sn~.Jan 0 v VIV v VI VIV VIVI IV v1e1o nJzoJpllv sn:>.Jano vdJb:JoJ.:JVW vBns~optrasJ I • V:JJsJad snun·i-(1 VIV J?lUOWa.Jj snzndo;J VIV v v v VIV VIVIO VSOl:lTaYVTSlf!IVjV/ d ?.J <>lf'f0 "S1i!I! d I • varnnuna vazo v V 31 U.J Oj? 1V 3 8UiffJ!1f[ r "71"ssnfdTfvan 3 I sua.J.Jn:>ap sfl.Jpa5ozilJ v VJfo]?qwo'/.J snuzv 0 wnff:t"i[iro.J:>vw .Ja:>v ll'•Av'IAV )>. )>. 0 sa,:>ads ~ Q"" ~ IJ> .. -· c: :} n ;:, ~ < 0' ;:, c:" c: .. ::!r .. Q...,~., Ill .. ~-~l~~.g Q .. 0 !!. n n Ill o n " -.Q .. ... 0 R" ;·10 g "'<~ ...... c: ...:::: " c: Q 0 c: 3 c: :;:- - .. ;:, " ~ - ;:,-· .. Q .....- .... n .,..... jj'-· Q fa ~. ~ no- c: Q 0' .. 0' 3 Q" Q ~() o- ... Ill ': Ill - Q c:" ..._ .. -· n - -· Q ;; !!. Q.. 0' I Q.. 'n ·0 n a c: n iO 3 Q.. ;:," - .0 -· 0 c:-· . c:"" ~. . " ...0 .. n ~ .. " 3 .. c: ;; .. 0' - ~I 3 R lo n ~- 3 .. .. Q 0 .." Q 0' j i "" n.. ..-· 3 1-· • n c: r -Q c: 'o~ 3 I~ suo! Jopossv

uoAue::> UOSJ!M U! suorJ.e!oossv l.UeJd U! sa,oads JO aoueu,woa a/\!letaH pue aouaJJnooo Z 318V.l

Lt{ 48

("Table 2, Continued")

Assia ~ .. llif.. ra t:.. t:.. t:.. t:.. 0 0 0 0 0 t:.. 0 t:.. Salix ssn t:.. • • • t:.. • • t:.. t:.. t:.. Sambucus mexicana t:.. •t:.. t:.. t:.. t:.. t:.. t:.. t:.. t:.. t:.. ll. t:.. t:.. Senecio doul!lasii t:.. t:.. t:.. t:.. t:.. t:.. t:.. t:.. t:.. t:.. t:.. t:.. Solanum xanti t:.. t:.. t:.. ll. t:.. Symphoricarvos mollis t:.. Toxicodendron diversilnhnm t:.. ... t:.. t:.. t:.. Ttichostema lanatum t:.. t:.. ll. t:.. t:.. t:.. t:.. Yucca whivvlei t:.. t:.. t:.. t:.. t:.. t:.. t:.. t:.. t:.. t:.. Herbaceous Amaranthus albus t:.. Ambrosia ac n.nth · ,nrnn t:.. Artemisia dou11lasiana ll. ll. t:.. t:.. t:.. ("Table 2, Continued")

..0 ~ Ci E

.. 3 i: 0 6 tl Scecies Ll Avena barbata b. Brassica f!eniculata b. b. •••b. b. b. b. Bromus diandrus - b. Bromus mollis Bromus rubens - b. Chaenactis f!labriuscala b. b. Chenopodium album ChloroJZalum oomeridianum b. Clarkia unf!uiculata b. Claytonia oerfoliata b. b. Convovulus arvensis Croton cali/~rnicus b. b. Datura meteln:.Jp. b. Dudleva son. b. b. Elvmus condensatus b. b. b. b. b. ErioJZonum elonf!atum Erodium cicutarium b. b. b. Erysimum caoitatum E schscholzia caesnitosn Cilia solendens b. b. Hemizonia fa.sciculata Heterotheca f!randiflora b. b. Hordeum leoorinum Lathvrus sv. b. Lotus strif!osus b. Luoinus hirsuitissimus Luoinus lati{olius b. Luoinus truncatus l~e~/tligfi~rix saxatihs var. Marah macrocarvus Marrubium vuluare lw I I I Melica imperfecta b. b. b. Mimulus brevioes Mimulus cardinalis Nemoohila sv b. Oenothera sv. 50

("Table 2, Continued")

Soecies 0 xalis 1> e s•c aorae I Paeonia californica Penstemon grinellii Phacelia sJJ. Pitvrostrama trianllularis IPoa .

Salvia colum bariae Solidatlo cali(ornica Stachvs albens SteJJhanomeria viruata Tvoha latifolia Vinca ma "or lw Zauschneria californica 51

lished trails. Associated species including Eriodictyon crassifo lium, California sagebrush (Artemisia californica), Cali

fornia buckwheat (Eriogonum f~sciculatum), scalebroom (Lepi dospartum sguamatum), bush groundsel (Senecio douglasii), Salvia mellifera, and annual grass species are prominent along drier margins of this riparian association. Herba ceous species include Mimulus cardinalis, hedge-nettle (Staehys albens), goldenrod (Solidago californica), cattail

(Typha latifolia), and PolypodiQ~ californicum.

Chaparral Chaparral is extensively developed on the uppermost slopes, ridges, and ravines on the west, north, and east parts of Wilson Canyon, and is composed primarily of numer ous broadleaf evergreen sclerophyllous species. Chaparral associations mingle or merge downslope with sagebrush-chaparral and sagebrush associations, becoming increasingly restricted to northerly slope aspects and ravines as sagebrush associations increase in dominance. Chaparral stands in ravines are increasingly interrupted by and eventually replaced with woodlands further downvalley. Scattered chaparral outliers occur on flat, mesa-like ridges or on north-facing aspects within sagebrush and annual grass communities. Except for interruptions by roads, numerous rock out crops, burned areas and occasional emergent oaks, chaparral 52 cover is nearly continuous, varying considerably in height, density, and composition of component shrub species. Aden- ostema fasciculatum-dominated stands are stunted, their widely spaced individuals ranging from 2 to 5 feet in height. The best developed communities, containing several co-dominant species, grow to 10 to 12 feet forming dense, nearly impenetrable thickets. The chaparral associations are: (5) Arctostaphylos spp.-Ceanothus spp.-Quercus spp., (6) Ceanothus crassifolius, (?) Ceanothus crassifolius-Adenostema fasciculatum, (8) Adenostema fasciculatum, (9) Cercocarpus betuloides, and (10) Eriodictyon crassifolium-Heteromeles arbutifolia.

Arctostaphylos ~.-Ceanothus ~.-Quercus ~· Association The Arctostaphylos-Ceanothus-Quercus association is the tallest and densest association in the chaparral with heights commonly from 6 to 12 feet and occasionally up to 15 feet. Canopies are usually closed but interruptions occur, especially where rock outcrops protrude through the canopy shrubs. This association occurs primarily in ravines and on steep to moderate north to northwest-facing slopes where it is usually sharply delimited from other chaparral associations on contrasting exposures or upslope crests of ridges. Characterized by the co-dominance of numerous woody evergreen species, most of which are stump-sproutersdensely intertwined, this association has the most abundant and di- 53 verse number of dominant or associated dominant species of all associations in the canyon. Six species of the 3 genera used to name this association are of greatest importance: Arctostaphylos glandul~, Ceanothus crassifolius, C. oliganthus, chaparral whitethorn (C. leucodermis), Quer cus wislizenii var. frutescens, and scrub oak (Q. dumosa). Ceanothus oliganthus and C. leucodermis are the two most widespread species, both beingdominants or co-dominants in 4) percent of all stands. The remaining major species are dominants or co-dominants or a lesser number of stands, at most 16 percent, and are associated dominants in more stands than those in which they are dominants. Species dominant in less than 20 percent of all stands of this association were listed as associated dominants in Table 2. The tendency of Arctostaphylos glandulosa to form dense thickets excluding other species is pronounced within this association. Distinct stands were segregated on the basis of this sole dominant, but more often Arctostaphylos glandulosa was dominant within portions of larger stands. Because of the dense, closed canopy, subshrub and herbaceous species are uncommon but do occur, especially near breaks in the canopy. Two of the most common sub shrubs are Eriodictyon crassifolium and rush rose (Helian themkffi scoparium), the former in some areas growing as high as shrubs of the upper canopy. Other elements are conspicuous here and there in the association. Wild cucumber (Marah macrocarpus), a climbing 54

vine, is especially prominent in the canopy during spring

and early summer~ Southern honeysuckle (Lonicera subspi cata var. johnstonii) occurs as a clambering shrub along

ravines. Spanish bayonet (Yucca whipplei) is promine~t on . rocky sites but is nowhere abundant.

Ceanothus crassifolius Association The Ceanothus crassifolius association is one of the most extensive, its single largest tract occurring on steep slope facets in the north-central portion of the canyon. Other significant areas are located in central and west- central portions. All locations have a predominant southeast to southwest exposure. Isolated representative stands occur at lower canyon elevations on plateau-like ridges. Density and height of the association vary from stand to stand. On steep, cliff-like, partially barren slopes with extensive erosional scars, discontinuous, widely spaced Ceanothus crassifolius individuals grow to J or 4 feet in height with annual grasses interspersed. Other stands are dense, having continuous coverage by shrubs 6 to 10 feet in height which are strongly intertwined 4 to 5 feet above the ground surface. Ceanothus crassifolius dominates JO of the J2 stands comprising this association and is co-dominant with annual grass and Rhus laurina in one each. Salvia mellifera and Adenostema fasciculatum are the most abundant associated dominants, occurring separately or 55

together in 84 percent of all stands. Eriodictyon crassi folium is locally abundant in 23 percent of all stands, and is listed as an associated dominant in Table 2. Other less 'frequent associated dominants are Ceanothus oliganthus, Cercocarpus betuloides, Ceanothus leucodermis, Quercus du

~, Q. wislizenii var. frutescens, Rhus laurina, and Arctostaphylos glandulosa. Elderberry {Sambucus mexicana), Platanus racemosa, Quercus agrifolia, and g. chrysolepis protrude sporadically along ravines. Subshrubs are abundant to sparse, depending on the density of the dominant shrub canopy. Two perennial bunch grasses, coastrange melic (Melica imperfecta) and pine bluegrass (Poa scabrella), are conspicuous on rocky, cliff sites. Annual grasses are abundant in canopy openings.

Ceanothus crassifolius-Adenostema fasciculatum Association Co-dominated by Adenostema fasciculatum and Ceanothus crassifolius, stands of this association are often transitional between those dominated by Adenostema fasciculatum and those dominated by Ceanothus crassifolius and occur predominantly on south-facing and east-facing slopes near crests of the highest ridges flanking the canyon. Most slopes are steeper than JO degrees, many being heavily dissected by rill and gullies. Soils are loose, thin, and stony, and show evidence of much erosion. Rock outcrops are common. Shrub canopies vary from discontinuous to closed. Where canopies are discontinuous because of gully dissec tion, admixtures of annual grass and subshrubs are abundant. Other stands have shrub coverages estimated in excess of 90 percent and are characterized as closed, with few annual or subshrub species present. Heights of the association range from 2 to 10 feet, the former height from aggregations of low subshrubs, the latter from aggregations of associated dominants such as .Arctostaphylos glandulosa or Ceanothus leucodermis in gullies or areas with accumulations of soil. Adenostema fasciculatum and Ceanothus crassifolius co-dominate all 18 stands of this association. Five other species occur as associated dominants. Salvia mellifera, the most abundant, is present in 50 percent of all stands. The remaining associated dominants, occurring in less than 18 percent of all stands, are: Arctostaphylos glandulosa, Ceanothus leucodermis, Eriogonum fasciculatum, and Erio dictyon crassifolium, the latter prominent on rocky, dis turbed sites along with Eriogonum fasciculatum, and an associated species, Yucca whipplei.

Adenostema fasciculatum Association The Adenostema fasciculatum association is probably adapted to one of the most adverse habitats in the canyon, its most notable development occurring along narrow ridges, spurs flanking ridges, or on nearly precipitous, rocky 57

slopes in the northwest and northeast portions of the can yon. Several small distinctive stands dominated by Adeno stema fasciculatum are located in the southern portion of the ,:;anyon on flat ridges surrounded by coastal sagebrush and stands dominated by annual grass. Soils of this association are formed from loose, de composed granodiorite or poorly indurated sandstone conglomerate and are extremely stony. Soils on the steeper slopes are often discontinuous because of heavy erosion and gullying, resulting in barren ground which is common throughout much of this association. The association is characteristically xerophytic. Adenostema fasciculatum, a sole dominant in 72 percent of the 36 stands, is one of the hardiest chaparral shrubs, having tiny, fascicled, linear leaves, and extensive root systems. Average height of the association is 4 feet. Stands most strongly dominated by Adenostema fasciculatum are low in stature, reaching from 2 to 4 feet and having discontinuous canopies. Some stands are 6 to 7 feet in height. The most striking characteristics of most stands of this association compared with those of other associations are the openness of the canopy and the exposed, predomi nantly barren soil, nearly devoid of herbaceous growth. Certain stands which contain Ceanothus crassifolius as an associated dominant are dense, being located in slightly more favorable ravine locations. 58

Adenostema fasciculatum is co-dominant with Eriodic tyon crassifolium and'Rhus laurina in 2 stands each and with annual grass and Artemisia californica in one each. Ceanothus crassifolius is an associated dominant in 30 per cent of all stands, Salvia mellifera in 25 percent, and Eriogonum fasciculatum, Ceanothus leucodermis, and annual grass in 14 percent. Other associated dominants are Cerco carpus betuloides, Quercus dumosa, Q. wislizenii var. fru tescens, Ceanothus oliganthus, Helianthemum scoparium, and deerweed (Lotus scoparius). Associated shrub species are scattered throughout the association but are generally much less common than in other chaparral associations. These include bigberry man zanita (Arctostaphylos glauca), Heteromeles arbutifolia, wild tree tobacco (Nicotiana glauca), golden yarrow (Erio phyllum confertiflorum), and wooly blue curls (Trichostema .lanatum). Quercus agrifolia and Sambucus mexicana are un common, but conspicuous, along with Yucca whipplei.

Cercocarpus betuloides Association The Cercocarpus betuloides association is one of the most limited in the canyon, occurring predominantly on the steepest slopes capable of supporting vegetation, many portions of which are precipituous, partially barren, and eroded to bedrock. Five of the 7 stands comprising this association are open, their component shrubs giving sparse coverage to the 59

underlying bedrock. Two exceptional stands are dense shrub aggregations estimated to exceed 80 percent in coverage with much of this coverage accounted for by associated dom- •inants. Heights of the dominant canopy shrubs range from 4 to 10 feet with an average of 6 feet. Tall and loosely spreading with greyish-white bark, Cercocarpus betuloides exhibits a distinctive appearance visible from a considerable distance. Subshrubs in the association are lightly scattered between the dominants and cling to the rocky slopes in much the same manner. Cercocarpus betuloides dominates 4 of the 7 stands comprising this association and is co-dominant in the re maining 3 along with Ceanothus crassifolius in one, Hetero meles arbutifolia and Rhus laurina in another, and Salvia mellifera in the third. Associated dominants are Artemisia californica, Aden ostema fasciculatum, annual grass, Ceanothus oliganthus, sugarbush (Rhus ovata), and Quercus wislizenii var. frutes cens. Associated shrub species are listed in Table 2, being too numerous to mention here.

Eriodictyon crassifolium-Heteromeles arbutifolia Association Comprised of 3 separate stands in close proximity, the Eriodictyon crassifolium-Heteromeles arbutifolia asso ciation is located on slopes similar to those of the Cerco carpus betuloides association but with exposures from north- 60

east to northwest. Extensive rock outcropping and gullying produce interrupted shrub cllliups intermixed with patches of annual grass and barren ground. Heights of the dominant canopy shrubs in these localized dense shrub aggregations range from 6 to 12 feet. The Eriodictyon crassifolium-Heteromeles arbutifolia association has close floristic affinities with the Arcto staphylos-Ceanothus-Quercus association which it closely resembles, containing several of the latter's dominants as associated dominants or associated species. Eriodictyon crassifolium and Heteromeles arbutifolia are the only co dominants common to all stands. Other co-dominants are Rhus ovata, R. laurina, Quercus dumosa, and Ceanothus cras sifolius. Associated shrub species are Adenostema fasciculatum, Ceanothus leucodermis, C. oliganthus, Cercocarpus betu loides, and Rhamnus ilicifolia. Subshrub species scattered between clumps of dominant shrubs include Eriogonum fasci culatum and Mimulus longiflorus. Marah macrocarpus is present as a clambering vine. Quercus agrifolia and Q. chrysolepis are prominent downslope where these stands merge into live-oak-dominated woodlands.

Sage brus h-C haparral Sagebrush-chaparral is composed of 4 associations, 3 of which contain different combinations of Salvia mellifera, an important member of the sagebrush community, and 2 im- 61 portant members of chaparral, Adenostema fasciculatum and

Ceanothus crassifoliu~, as co-dominants. The fourth asso ciation is dominated by Rhus laurina, an arboreal-like ·shrub characteristic of California's sagebrush which is also found in chaparral. Sagebrush-chaparral occupies large tracts on predom inantly south-facing slopes dissected by ravines with barren cliff slopes along their margins. Sagebrush chaparral is most strongly developed at elevations ranging from 2500 to JOOO feet intergrading upslope with chaparral. Transitions between chaparral and sagebrush-chaparral are often gradual, necessitating arbitrary divisions between stands in which Salvia mellifera co-dominates(sagebrush chaparral), and stands in which Salvia mellifera is, at most, an associated dominant(chaparral). Individual stands of sagebrush-chaparral are scat tered throughout the chaparral at elevations above and isolated from areas of maximum development of sagebrush chaparral and also in annual grass and mixed lifeform areas in the eastern portion of the canyon. Stands of Rhus laurina are most common in ravines, alluvial areas or on the steepest south-facing slopes in areas dominated by sagebrush. Sagebrush-chaparral associations are: ( 11) Ceano·chus crassifolius-Salvia mellifera, (12) Adenostema fasciculatum Salvia mellifera, (1J) Adenostema fasciculatum-Ceanothus crassifolius-Salvia mellifera, and (14) Rhus lau~ina. 62

Ceanothus crassifolius-Salvia mellifera Association

The Ceanothus crassifolius-Salvia mellifera associa-

tion is located on slopes sim~lar to those of chaparral

associations but generally at lower elevations. Heights of

the association average 5 feet with Ceanothus crassifolius

generally exceeding Salvia mellifera. Emergent associated shrub species aggregating in gullies are from 7 to 9 feet

in height. Densities vary within the association. Some stands are closed, forming a continuous dense canopy; others are discontinuous to open with abundant annual grass and rock

outcrops in canopy openings.

Ceanothus crassifolius and Salvia mellifera co-dominate all 12 stands of this association.

Adenostema fasciculatum is an associated dominant in

83 percent of these stands, occurring predominantly on drier, rockier spurs. Other associated dominants are Erio- dictyon crassifolium, Heteromeles arbutifolia, and Rhus laurina, the first species in rocky sites associated with

Adenostema fasciculatum, the second and third in gullies.

·Associated shrub and subshrub species are intermixed throughout the association, subshrubs being especially abundant. Quercus agrifolia and Platanus racemosa are co~only found in association with Heteromeles arbutifolia and Rhus laurina in adjacent stands. Yucca whipplei is 6J

conspicuous.

Adenostema fasciculatum-Salvia mellifera Association The most extensive development of the Adenostema fas

c~culatum-Salvia mellifera association occurs in the western upland portion of Wilson Canyon, an area underlain by sandstone-conglomerate (Elsmere Member), the distributions of which correlate closely, but not exclusively. Scattered stands are also located at lower elevations in proximity to stands dominated by Salvia mellifera and in eastern portions of the canyon surrounded by annual grass and mixed lifeform communities. Soils are shallow or in many places non-existent, as shown by numerous shrubs rooted directly in the rocky substrate. Slope exposures vary but a predominant southward trend is apparent. Height and density of the association average 5 feet. Occasional Adenostema fasciculatum and Salvia mellifera shrubs emerge at 6 to 7 feet. Density is relatively higher than in stands dominated purely by Adenostema fasciculatum ·(see transect data for stands 125 and 248 in Appendix III). Annual grasses are abundant in numerous canopy openings. Adenostema fasciculatum and Salvia mellifera co-dominate 94 percent of the 16 stands comprising this assocla- tion; annual grass is co-dominant with Adenostema fascicu latum and Salvia mellifera in the remaining 6 percent. Ceanothus crassifolius is an associated dominant in 37 per- 64

cent of all stands, usually locally dominant in the steeper, rockier portions along with Eriodictyon crassifoli~~, a~ associated dominant in 31 percent of the stands. One interesting herbaceous species in this associa tion is soap plant (Chlorogalum pomeridianum), a member of the lily family, which was found predominantly along ridges in sandstone-conglomerate areas.

Adenostema fasciculatum-Ceanothus crassifolius Salvia mellifera Association The Adenostema fasciculatum-Ceanothus crassifolius-

Salvia mellifera association occurs predominantly along ridges and spurs in the north-central portion of the can yon. The association is generally downslope from stands dominated by Adenostema fasciculatum and Ceanothus crassifolius and is closely associated with the Ceanothus crassifolius-Salvia mellifera association with which it interdig itates and with the Adenostema fasciculatum-Salvia mellifera association with which it is transitional.

The Adenostema fasciculatum-Ceanothus crassifolius-

Salvia mellifera association was segregated because of

(1) the importance of Adenostema fasciculatum as a co-domi nant on ridg.elines, and ( 2) shifting dominance by Adeno- sterna fasciculatum, Ceanothus crassifolius, and Salvia mel lifeia in areas too small to map individually necessitated description of larger stands by co-dominance of all three species. The density of this association averages less than that of the Ceanothus crassifolius-Salvia mellifera association because of the inclusion of scatte~ed and

stunted Adenostema fasciculatum individuals. Heights vary,

ranging from Adenostema fasciculatum shrubs 3 feet in 'height to Salvia mellifera shrubs 5 feet in height, and Ceanothus crassifolius shrubs to 6 or 7 feet. Adenostema fasciculatum, Salvia mellifera, and Cean-

othus crassifolius co-dominate all six stands of this

association. Annual grass is an associated dominant in one

stand which has the appearance of a shrubby savanna.

Rhus laurina Association

The Rhus laurina association was placed in the

sagebrush-chaparral physiognomic type because Rhus laurina

is common in both sagebrush and chaparral communities. In addition, several chaparral species are present in the Rhus

laurina association. The Rhus laurina association is composed of nine

stands in three distinctive sites at lower elevations of

the canyon: (1) ravines, (2) semi-cliffs, (J) alluvial

flats.

Ravines

Linear stands form in ravines which are dominated by

Rhus laurina with Ceanothus crassifolius and Salvia melli-

fera as associated dominants. Stands are 10 feet in height

and are extremely dense. Because of the dense canopy,

associated species are restricted to upslope margins or

rare interstices in the canopy. Associated shrub species -- - k - '----', 66 are Cercocarpus betuloides on upslope cliff margins, Baccharis glutinosa, Salix spp., Artemisia douglasiana, and an occasional fern, Polypodium californicurn. Eriogonum fasciculaturn and Yucca whipplei are scattered throughout these stands, mostly along the upslope margins.

Semi-Cliffs Semi-cliff sites are the most numerous in the association. Slopes are southerly in aspect, with the exception of one stand, and are characterized by prominent Rhus laurina shrubs scattered over a partially barren, loose soil surface. Rhus laurina dominated four association stands and was co-dominant with Heteromeles arbutifolia in one. Erio- gonurn fasciculaturn is an important associated dominant in J of these south-facing standsf its appearance being one of a small subshrub 2 to J feet in height betweeri areas of Rhus laurina and partially barren ground. Associated dominants are Salvia mellifera, Ceanothus crassifolius, and Eriodictyon crassifoliurn. Conspicuous subshrubs and shrubs are Salvia apiana, Lotus scoparius, and Artemisia californica. Chia (Salvia colurnbariae) and Erodiurn cicutariurn are abundant annual species in spring months on sparsely vegetated sites along with wild mustard (Brassica geniculata). Alluvial Flats Stands on alluvial flats are dense aggregations of Rhus laurina to 10 or 12 feet in height. Associated shrub species are Heteromeles arbutifolia, Rhamnus ilicifolia, and hollyleaved cherry (Prunus ilicifolia). Accompanying these stands are overhanging Quercus agrifolia trees of adjoining woodland stands.

Sagebrush Sagebrush is dominated by softleaved, predominantly marcescent shrubs and subshrubs common to the sagebrush areas of coastal southern California. Though annual grass is abundant in canopy openings, it only occasionally at- tains co-dominance in stands of this physiognomic type. Broadleaf evergreen chaparral shrubs are present but are uncommon, usually appearing along ravines or hollows. Scattered stands of sagebrush are intermixed with chaparral and sagebrush-chaparral at elevations in excess of 2000 feet but the largest core area of sagebrush is below 2000 feet in the south-central portion of the canyon. Canopy heights are generally more uniform and lower in stature than those of sagebrush-chaparral and chaparral. Subshrubs occupy significant areas within this type, especially in stands marginal to those of mixed lifeform with which they strongly interdigitate on their eastern boundary and share similar species.

. . . ~. ,., 1.-G-...,.;.;:.. ·~··•' #_" :. ·•·· ..·'·. 68

The two sagebrush associations are: (15) Salviamelli fera, and (16) Salvia'mellifera-Artemisia californica.

Salvia mellifera Association

The Salvia mellifera association comprises 40 s~ands, some of which are isolated within and strongly delineated from surrounding grass-dominated slopes in the eastern por tion of the canyon or are interspersed with and in places transitional to sagebrush-chaparral and chaparra+. At intermediate elevations of 1600 through 2000 feet in the south-central portion of the canyon is the largest, nearly continuous tract of sagebrush. Except for inter ruptions by live oak-dominated woodlands or grass and mixed lifeform-dominated stands on steeper, rockier sites, slopes of this area are dominated by a relatively even shrub cover ranging from 4 to 6 feet in height. Rhus laurina, con spicuous because of its dark green foliage and greater height, frequently to 12 feet, sporadically dots the slopes of this association or aggregates in ravines with other uncommon chaparral shrubs. The dominant shrub canopy is broken by masses of sub shrubs 2 to 3 feet in height accompanied by abundant annual grass. Rock outcrops are abundant on slopes which steepen to the point where shrub growth becomes discontinuous or patchy and no longer obscures the underlying substrate. Salvia mellifera is a sole dominant in 65 percent of all stands and is co-dominant with Eriodictyon crassifolium in 13 percent and with annual grass in 10 percent. Other lesser co-dominants are Rhus laurina and Eriogonum fasciculatum. Adenostema fasciculatum and Ceanothus crassifolius are the most common associated dominants, particularly in stands transitional to chaparral and sagebrush-chaparral, occurring in 42 and 28 percent, respectively, of all stands. Adenostema fasciculatum dominates ridges within stands domi nated by Salvia mellifera; Ceanothus crassifolius· dominates locally along ravines. Eriodictyon crassifolium is conspic uously dominant on the rockiest sites and forms dense colonies practically excluding Salvia mellifera and other chaparral shrubs.

Salvia mellifera-Artemisia californica Association The Salvia mellifera-Artemisia californica association occurs in four distinct stands on moderate to steep hillside slopes of southerly aspect and on alluvial bottom land. All stands are at elevations below 2000 feet and in close proximity to stands of the Salvia mellifera association or stands of the mixed lifeform physiognomic type. Variation in densities and heights of stands range from continuous shrub growth with little herbaceous undergrowth to open stands with numerous subshrubs and abundant herbaceous growth. Canopy heights range from 2.5 feet where localized aggregations of subshrubs occur to 5 or 6 feet where Salvia mellifera and Artemisia californica grow 70

densely intertwined. Occasional Rhus laurina shrubs pro trude above the general shrub canopy with heights of 10 feet.

Artemisia californica and Salvia mellifera co-d')mi nate all stands of this association and are accompanied by

Adenostema fasciculatum, Eriogon~~ fasciculatum, Eriodic tyon crassifolium, Lotus scoparius, and annual grass as associated dominants, especially on disturbed sites or ridges.

Mixed Lifeform

Areas of mixed lifeform are centered in the southern and eastern portions of Wilson Canyon and are closely associated with areas dominated by annual grass. Varying combinations of shrubs, subshrubs, and herbaceous annual grass lifeforms dominate, the latter being especially prom inent in most stands. Scattered stands occur along ridge lines and south-facing, partially barren slopes in chapar ral and sagebrush-chaparral areas and along roadsides.

Two associations appear very similar but differ slightly in dominant shrub elements: (17) Artemisia cali fornica-Eriogonum fasciculatum-Annual grass, and

(18) Adenostema fasciculatum-Eriodictyon crassifolium-Erio gonum fasciculatum-Annual grass. 71

Artemisia californica-Eriogonum fasciculatum Annual grass Association The Artemisia californica-Eriogonum fasciculatum- annual grass association is composed of shrub, subshrub, and herbaceous lifeforms and is closely related to the Salvia mellifera-Artemisia californica association because of similarity of species and geographical proximity but contains greater coverage by annual grass. Almost all of the JO stands of this association are in the southeastern portion of the canyon below 1900 feet. Centered on a series of three northeast-southwest trending parallel ridges and valleys, this association is most fully devel oped on northwest-facing slopes and on alluvial canyon bot toms. It interdigitates with grass-dominated stands on south-facing slopes, with live-oak woodlands on valley alluvial sites, and contains scattered outliers of chaparral along ridges. Three distinctive stand types were delineated on the basis of site location and on height and density of compo nent shrub and herbaceous species. These are: (1) stands on northwest-facing slopes, (2) stands on alluvial valley bottoms, and (J) stands on southeast and southwest-facing slopes.

Northwest-Facing Slopes Stands on northwest-facing slopes varying from 28 to 45 degrees in slope but often approaching 50 degrees ex- 72

hibit a relatively continuous, even shrub cover 3 to 5 feet ·in height dominated by Artemisia californica. Annual grass occupies the steepest portions, which are in many places 'partjally barren; Eriogonum fasciculatum is prevalent on drier spurs and Adenostema fasciculatum tends to predominate on the uppermost portion of the slopes on which these stands are located. Downslope the stands become denser as they merge into stands on level alluvial land. Chaparral shrubs such as Ceanothus crassifolius, C. oliganthus, and Rhamnus ilicifolia are at the base of undercut slopes or in small gullies along the face of the slopes.

/ ~Alluvial Valley Bottoms ~ Stands on alluvial valley bottoms are closed to discontinuous, forming an interrupted shrub cover dominated by Artemisia californica and Eriodictyon crassifolium varying from 5 to 7 feet in height. Within this shrub matrix, dense clumps of Rhus laurina 8 to 10 feet high are present. Partially barren areas resulting from repeated stream out wash interrupt the shrub canopy frequently. Such areas are occupied characteristically by scattered shrubs of Palmer goldenbush (Haplopappus palmeri ssp. pachylepis), Lepido- spartum sguamatum, Senecio douglasii, and numerous her-

i baceous species listed in Table 2. Elymus condensatus is conspicuous in these stands, heights of 5 to 8 feet being common. Platanus racemosa, Baccharis glutinosa, and Salix spp. are usual constituents of these stands. 73

Southeast- and Southwest-Facing Slopes Stands on southeast- and southwest-facing slopes characterized by discontinuous shrub clumps 2.5 to 3.5 feet high dominated by Eriogonum fasciculatum are much less dense than most areas of this association. Annual grasses such as Avena barbata, Bromus diandrus, soft chess (B. mollis), B. rubens, and Hordeum leporinum cover the intervening ground. Artemisia californica is much less abundant in these stands, usually being restricted to small notches within these south-facing slopes. Adenostema fasciculatum is more abundant on the upslope margins of these stands as well as along ridges of the association.

Artemisia californica is the most characteristic and widespread shrub of the association, being dominant in 30 percent and co-dominant in 83 percent of the 30 stands

comprising the association. Eriogont~ fasciculatum is domi nant in less than 3 percent of all stands but is co-domi nant in 27 percent. Annual grass is co-dominant in 30 per cent; Eriodictyon crassifolium in 20 percent of all stands, most notably on alluvial areas where this species forms dense clumps to 7 feet in height. A surprisingly large number of shrubs characteristic of chaparral grow in this association as associated species. Subshrub species are more prevalent on the grassier slopes of the association. Of the herbaceous species, Brassica geniculata is the most conspicuous, forming in many places 74

a yellow carpet during spring and early summer. Scattered throughout the association, especially on north-facing slopes and on valley bottoms, are Quercus agrifolia and Platanus racemosa.

Adenostema .fasciculatum-Eriodictyon crassifolium Eriogonum fasciculatum-Annual grass Association The Adenostema fasciculatum-Eriodictyon crassifolium- Eriogonum fasciculatum-annual grass association consists of J4 stands varying considerably in the proportion 'of area dominated by mixed lifeforms. Some stands are of open, low scrubby, scattered shrubs and subshrubs 2.5 to J.5 feet tall surrounded by abundant annual grass; other stands contain dense shrub clumps 5 to 7 feet high with little, if any, herbaceous growth. Though similar in appearance to the Artemisia californica-Eriogonum fasciculatum-annual grass association, this association was segregated because of the absence of Artemisia californica as a dominant and because of a relative increase in dominance by Adenostema fasciculatum and Eriodictyon crassifolium. Four stand types were delineated on the basis of

site: (1) roadsides, (2) alluvial flats, (J) ravines and adjacent slopes, and (4) ridges in chaparral areas.

Roadsides Stands along all roadsides are the result of continued vegetative interference by construction and maintenance 75 of United States Forest Service access roads and are dis tinct from surrounding undisturbed vegetative stands. Adjacent roadcut and landfill material are co-dominated by annual grass and subshrubs, Eriogonum fasciculatum and Eriodictyon crassifolium being the most important dominants. Occasional shrub members appear from adjacent chaparral stands. Two subshrubs found here but not recorded else where in the canyon were cudweeds (Gnaphalium californicum and G. microcephalum). Herbaceous species not found else where include bindweed (Convovulus arvensis), farewell-to spring (Clarkia unguiculata), lupine (Lupinus truncatus), bird's foot trefoil (Lotus strigosus), and Mimulus brevipes.

Alluvial Flats Stands on alluvial flats surrounded by the Artemisia californica-Eriogonum fasciculatum-annual grass association in the lower portion of the canyon are subject to repeated disturbances by stream outwash, the destructive effects of hikers and off-road motorcycle enthusiasts, and mechanical grading. Eriodictyon crassifolium dominates these stands, apparently as a stoloniferous, weed-like invader. Rhus laurina protrudes above the open canopy with abundant annual grass and subshrubs in the lower stratum.

Ravines and Adjacent Slopes Interdigitating with grass-dominated ridgeline stands are scrubby mixed grass-subshrub-shrub stands in ravines and adjacent slopes in the eastern portion of the canyon. 76

Slopes adjacent to deeply incised ravines are steep to precipitous, deeplJ eroded facets with conspicuous rock outcrops. Eriodictyon crassifolium is locally dominant, forming dense colonies 4 to 6 feet high clustering on the rockiest sites or in areas of recent soil slippage. Annual grass provides the most uniform coverage on non-barren sur faces. Eriogonum fasciculatum and other--subshrubs are lightly scattered, occasionally forming low, prostrate mats 1.5 to 2.5 feet high. Adenostema fasciculatum is. sporadi cally dispersed as an upright shrub 3 to 6 feet tall. Ravine bottoms are most conspicuously occupied by Rhus laurina and Ceanothus crassifolius, the former reaching to 12 feet.

Ridges in Chaparral Areas Surrounded by chaparral stands are stands dominated by annual grass and scattered subshrubs and shrubs, grass providing the most cover. These stands occur along ridges as well as on steep south-facing slopes of 40 to 50 degrees in the southwestern portion of the canyon. Eriogonum fas ciculatum and Adenostema fasciculatum are the most preva lent subshrubs and shrubs, but others including Salvia mellifera, S. apiana, and Lotus scoparius are abundant enough to be considered associated dominants. Perennial bunchgrass is prominent.

Adenostema fasciculatum, Eriodictyon crassifolium, Eriogonum fasciculatum, and annual grasses dominate the 77

association, each occurring respectively in 42, 38, 65, and

56 percent of all stands as dominants or co-dominants.

Eriodictyon crassifolium is a sole dominant in 18.percent

of all stands. The most important associated dominants are

Ceanothus crassifolius, C. leucodermis, and Helianthemum

scoparium, a low prostrate subshrub 1.5 to 2 feet tall.

Annual Grass

Areas of annual grass were separated from a.reas of mixed lifeform, even though individual shrubs or small shrub aggregations are present, because the overwhelming majority of area is occupied by annual grass. Difficulties arose in delimiting stands of annual grass because no area exceeding a minimal mappable area was devoid of shrubs or subshrubs.

Boundaries were drawn to enclose as many stands of annual grass or of mixed lifeform as possible, provided these were of the minimal mappable area. If shrub clumps were scat tered such that no reasonable unit could be delimited, they were ignored as mappable units but were described in field notes, Such compromises were necessary if effective field mapping and description of grasslands were to proceed. The result was the delimitation of the field map and on the final map(Figure 10) of reasonable stands defined by domi nance of annual grass.

Annual Grass Association

The annual grass association comprises JO stands occupying extensive areas in the eastern half of the 78

canyon and scattered patches on steep south-facing slopes within sagebrush and chaparral areas. Stands also occur along margins of firebreaks on major ridges. In the eastern portion of the canyon, ridges are occupied by the annual grass association which grades down slope into or interdigitates with stands of mixed lifeform developed in ravines and on their adjacent slopes. At lower elevations the annual grass association appears on south-facing slopes interdigitating with the Artemisia cali fornica-Eriogonum fasciculatum-annual grass association. Coverage by annual grass is estimated to exceed 80 percent in all stands, the remainder of ground being pre dominantly barren because of soil slippage and rock out cropping or occupied by scattered shrubs and subshrubs. Grass heights vary from 6 inches to 3 feet. Annual grasses include Avena barbata, Bromus diandrus, B. mollis, B. rubens, and Hordeum leporinum. Because of the wide range of this association through out all elevations of the canyon and in proximity to many shrub stands, the list of associated shrub and subshrub species is extensive and is found in Table 2. Brassica geniculata is an annual species common in all stands of this association, especially in late spring and early summer. Several other herbaceous species of interest are listed in Table 2. 79

Sparsely Vegetated Surfaces Numerous sparsely vegetated surfaces are found throughout Wilson Canyon on a variety of terrain and occupy considerable amounts of area. These predominantly barren surfaces are not without sparingly distributed species, some perennial, the majority ephemeral. For much of the year these surfaces appear lifeless, but spring and summer months produce a profusion of annual species, many of which are weedy in nature. Twenty-five units were mappable as sparsely vegetated surfaces and many smaller units of pre dominantly barren surface in other associations were too small to be recorded on the map. Sparsely vegetated surfaces occur in three basic type sites, each of which is associated with a particular terrain feature or resulted from management programs of the United States Forest Service and the Los Angeles County Flood Control District. The sites are (1) cliffs, (2) firebreaks, and (3) outwash areas.

Cliffs Predominantly barren cliffsites are visually dominant in many areas of the canyon and constitute a majority of units mapped. Planimetrically they do not occupy large areas because of their location on steep, precipitous slopes, Slope surfaces are mostly of barren rock outcrops and shallow, incised ravines. Soils, if present, are in scattered pockets usually occupied by annual grass and sub- 80

shrubs such as Lotus scoparius, Eriogonum fasciculatum, and Salvia apiana. Yucca 'whipplei and shrubs of Rhus laurina, Heteromeles arbutifolia, and Cercocarpus betuloides are the most conspicuous members but Hre widely scattered, covering little area.

Firebreaks Predominantly barren areas result from shrub clear ance by the United States Forest Service along major ridges or on relatively flat upland areas, e.g., on the Elsmere Member, Many areas mapped as sparsely vegetated are now developing a thick cover of annual grass seeded for cover age or contain resprouts of shrub species such as Adena sterna fasciculatum, Quercus dumosa, and Arctostaphylos glandulosa present prior to clearance. Subshrubs, among them Lotus scoparius, Eriogonum fasciculatum, and Helian themum scoparium, are common.

Outwash Areas Numerous earth catchment dams constructed by the Los Angeles County Flood Control District have created flat basins of sand, boulders, and other depris that are sparsely vegetated. These basins commonly contain par tially buried, dead Quercus agrifolia trees. Upstream are areas which have been scoured by rushing waters and are incised by numerous interfingering dry creek beds contain ing large boulders piled upon one another and abundant, deep sand. 81

A characteristic set of shrub and herbaceous species

are found in these areas, many of which are weedy annuals.

Salix spp. and Baccharis glutinosa form bands of riparian

growT.h restricted to immediate streamside locations. Wide

ly scattered individuals of Lepidospartum sguamatum, Erio

dictyon crassifolium, Nicotiana glauca, Haplopappus palmeri

ssp. pachylepis, and Senecio douglasii sporadically dot the surface, often in narrow bands adjacent to dry creek beds.

The most common and characteristic weedy herbaceous species are tumbleweed (Amaranthus albus), sand-bur (Ambrosia acan

thicarpa), pigweed (Chenopodium album), croton (Croton californicus), and telegraph weed (Heterotheca grandiflora).

In one area are introduced species including Bermuda but tercup (Oxalis ~-caprae), and an Oenothera species. In the vicinity of an old dwelling, jimsonweed (Datura meteloides) is an uncommon weedy species. A dense colony of cattail (Typha latifolia) is near the dam at the canyon outlet, surrounded by Salix spp. and Baccharis glutinosa. CHAPTER IV

AREAL RELATIONSHIPS Vegetation is, in part, a product of its environment and simultaneously is a factor which modifies its habitat. Interrelationships of vegetation and habitat are exceed ingly complex and have been analyzed only for relatively minute portions of the earth's surface. The intricacies of vegetation-habitat data for Wilson Canyon are not known. Nevertheless, certain very general relationships between vegetation and environment can be observed almost anywhere and at the time of observation may be regarded merely as areal coincidence subject to further investigation and explanation. The observations which have been made in Wilson Canyon provide a partial record of areal coincidence of vegetation and selected habitat factors. Inferences of some interrelationships of vegetation and habitat in Wilson Canyon have been drawn from literature available on the vegetation and broad habitat categories in the shrub commu nities of southern California and from personal observation of the study area.

General Observations Climatic and pyric influences are responsible for the major distributions of chaparral, sagebrush-chaparral,

82 sagebrush, mixed lifeform, and annual grass physiognomic types in Wilson Canyon. Special edaphic conditions of year round surface or groundwater availability coincide with occurrence of the woodland physiognomic type. Chaparral in the study area is a successional scrub vegetation represented by at least three indistinct stages resulting from three separate fires in the last twenty years. Sagebrush elements are strongly represented in nearly all areas of chaparral dominance and form many stands in co dominance with chaparral species, i.~., sagebrush-chaparral. Sagebrush-chaparral appears to be a seral formation result ing from continued and repeated burning which maintains sagebrush elements as dominants. With the exception of the Arctostaphylos-Ceanothus Quercus association, large areas of the chaparral are characterized by varying proportions of a few dominant species and an essentially similar complement of associated species of relatively equal proportions. Stands of the Arctostaphylos-Ceanothus-Quercus association do not fit this observation above, being composed of numerous dominant or co-dominant species, many of which are associated species in the other chaparral associations. Though specific climatic data are not correlated with specific plant associations, a general trend of vegetative change is apparent with increasing altitude, increasing precipitation, and decreasing temperature. These trends 84 are: (1) increasing shrub height and density, and (2) increasing abundance of evergreen, sclerophyllous shrub species.

Specific Observations Superimposed upon the broad vegetative patterns are variations in composition and physiognomy associated with specific or secondary habitat factors. The secondary factors related to vegetative distributions are physical and cultural; the former with aspects of terrain and geo logy; the latter with fire and various land uses.

Terrain and Vegetation Vegetative distributions are related to four aspects of terrain. These are (1) slope orientation, (2) slope angle, (J) drainage, and (4) ridges.

Slope Orientation Differences in vegetative communities are observed between contrasting ~lope aspects, particularly those of a north-south orientation. Within the chaparral are a number of stands illustrat ing differences between north- and south-facing slopes.

Stands of the Arctostaphylos~Ceanothus-Quercus association, the densest and tallest chaparral association, occur on north- and northwest-facing slopes. Typically dense and composed of numerous species, these stands contrast strongly with stands on adjacent south-facing slopes which are much 85

less dense and are dominated by one or two major species. In the southeast portion of the canyon, differences.in vegetative composition and height are evident from compar isons of contrasting north- and south-facing slopes. North facing slopes within the Artemisia californica-Eriogonum fasciculatum-Annual grass association are covered predomi nantly by a uniform growth of Artemisia californica 3 to 5 feet high. South-facing slopes are occupied by a mixture of scattered subshrubs and annual grass of much lower sta ture and greater openness.

SlopeoAngle Slope angle was observed to have little effect on vegetative distributions except where slopes became precip itous. On such slopes vegetation disappeared as a contin uous cover, usually being restricted to small pockets of soil accumulating on ledges or lodging in crevices. Occa sional large chaparral shrubs were observed to cling to rock walls. Stands of the Cercocarpus betuloides association were associated with steep, precipitous slopes aswereboth stands of the Pseudotsuga macrocarpa association.

Drainage Drainage channels and areas receiving constant water seepage are occupied by woodland vegetation or scrub vegeta tion taller and denser than that surrounding on drier mar gins upslope. Almost all oak-dominated woodlands with con stituent deciduous trees are found within drainage channels. 86

Areas receiving large amounts of outwash material at the mouths of canyons·contain species, both shrub and her baceous, not generally found within well developed sage brush and chaparral stands. Shrub species found on th~se outwash areas include Lepidospartum squamatum, Nicotiana glauca, Haplopappus palmeri ssp. pachylepis, and Senecio douglasii. Herbaceous species include Amaranthus albus, Ambrosia acanthicarpa, Chenopodium album, Croton califor nicus, Datura meteloides, and Heterotheca grandiflora. Vegetation along waterways was usually distinct from surrounding vegetation in all areas of the canyon and is shown by the recognition of many linear stands on the vege tation map.

Ridges Vegetation on ridges and spurs flanking major ridges often strongly contrasted with the vegetation of downslope margins. Numerous examples shaw the distinctiveness of the ridgeline vegetation. In the eastern portion of the canyon, ridgelines were dominated by annual grass. Intervening ravines and adjoining slopes were occupied by a shrub subshrub-annual grass mixture appearing to be developing into shrub dominated stands. In chaparral areas, stands dominated almost purely by Adenostema fasciculatum contrast with stands downslope domi nated by other shrub species such as Ceanothus crassifolius, C. leucodermis, C. oliganthus, or Quercus wislizenii var. 87 frutescens. In sagebrush areas in the central portion of the can yon, stands of the Salvia mellifera association occupy hol lows and areas downslope from ridges, Ridges are occupied by subshrubs such as Eriogonum fasciculatum, Salvia apiana, and Lotus scoparius, and annual grass.

Geology and Vegetation

Closely related patterns of lithology and ~aulting are associated with distinctive vegetative patterns in two areas of the canyon. These occur (1) along Hospital Fault, and (2) along the inferred fault trace on the north and west margin of the Elsmere Member.

Hospital Fault Artemisia californica is a dominant or associated dominant in stands south of the Hospital Fault but occurs in only one small stand north of the fault. The absence of Artemisia californica on granite-diorite north of the fault becomes more striking where abrupt transitions of stands dominated by Artemisia californica into stands without this shrub are viewed across the fault trace. South of the fault are sediments of the Pacoima Formation. Terrain on both sides of the fault were burned in the Loop Canyon Fire of 1966, resulting in simultaneous oppor tunity for re-colonization by numerous shrubs. In the ensuing years many shrubs, with the exception of Artemisia californica, have re-colonized both sides of the fault with- 88

out apparent preference. These shrubs include Eriogonum fasciculaturn, Salvia mellifera, Adenostema fasciculatum, Eriodictyon crassifolium, Lotus scoparius, and Ceanothus crassifolius. The absence of Artemisia californica north of the fault may be related to the abruptly increased gradient north of the fault resulting in more rapid water runoff; coupled with shallower, stonier soil profiles which further lessen water retention. These shallow profiles, resulting from the hardness of the underlying granite-diorite probably restrict penetration of water-seeking roots of Artemisia californica. Deeper soils available south of the fault on sediments of the Pacoima Formation are apparently adequate to sustain life of this shrub during the dry season.

Elsmere Member A distinctive plant association in which Salvia mel lifera and Adenostema fasciculatum dominate is closely associated with the Elsmere Member. The inferred fault trace on the north and west, corresponding to the upslope margin of this sedimentary formation, is correlated with an abrupt transition of the Adenostema fasciculatum-Salvia mel lifera association to stands of the Ceanothus crassifolius association, or into stands of the Arctostaphylos-Ceanpthus Quercus association on granite-diorite. Though exceptions are seen in the field, for example stands of the Adenostema fasciculatum-Salvia mellifera association occurring outside 89 limits of the Elsmere Member, the close coincidence of the Adenostema fasciculatlim-Salvia mellifera association and the deposits of the Elsmere Member is apparent. Downslope margins of the Elsmere Member, though not demarcated by a fault line, are revealed by relatively abrupt transitions into stands dominated by Ceanothus cras sifolius on different lithology. The Adenostema fasciculatum-Salvia mellifera associa tion appears to be more xerophytic than surrounding asso ciations on different lithology. Stands of this association are much shorter and more open grown than those stands of adjacent associations previously mentioned. An explanation may be lessened water retentive capacities of the sediments and light soils of the Elsmere Member, which is composed of sandstones, siltstones, and conglomerates, or in mineral deficiencies of these sediments. Another explanation may be that runoff of upper slopes to the west submerge along the fault trace, flow beneath the formation, and emerge on its downslope margins to the east. Along the fault trace are scattered Quercus agrifolia trees and several herba~ ceous species, among them Artemisia douglasiana, Lupinus latifolius, Claytonia perfoliata, and Elymus condensatus, which appear to be indicative of moist conditions. Away from the fault these species Eapidly disappear as water availability diminishes, their place being taken by annual grass. 90

Fire and Vegetation

Fire produces both immediate, obvious effects on the

vegetation well known to all, and extended, subtle effects

less well known. Immediate effects include destruction of

the vegetative cover with consequent, striking patterns of

burned and non-burned areas, rapidly altered floristic com

position, and physical evidence of charred shrub and arbo

real forms prior to fire.

When viewed aerially,one of the most striking con

trasts in the canyon is between shrub and grass dominated

areas. In the eastern portion of the canyon is a patchwork

shrub-subshrub-annual grass complex of the mixed lifeform

physiognomic type-annual grass association which has emerged

in an area burned off in the 1966 Loop Canyon Fire. The western margins of this complex are easily decipherable

from shrub dominated areas unburned by this particular fire.

Differences in floristic composition between this

burned area and shrub areas further west are striking. The

burned area supports a distinctive set of dominant and

associated species, distinctive because of their unusual

abundance when compared with unburned shrub areas. Shrub

and subshrub species dominant here, including Lotus scopar

ius, Eriogonum fasciculatum, a~d Eriodictyon crassifol~.um.

are apparently relic in unburned areas, being restricted as local dominants on some of the rockiest ridges and slopes available or present as subshrubs beneath an overtopping 91

shrub canopy. In the 1966 burn areas the above species form scattered, dense mats'interspersed among areas of annual grass dominance. In addition several herbaceous species occur in this area which were not found nor collected from shrub areas. In 1919 Wilson Canyon was completely denuded by a fire which blackened much of the western San Gabriel Mountains. 1 Five subsequent fires have occurred in different portions of the canyon, their passing recorded by the blackened remainders of Quercus agrifolia and Pseudotsuga macrocarpa trees and stumps, by skeletal remnants of various shrub species live with resprouting stems, or by charred and decaying snags and branches on the ground surface. Such evidence is present throughout the canyon. Secondly and much subtler, is the influence of fire on the composition and successional status of apparently "undisturbed" shrub stands long after most outward signs of the passing of fire have disappeared. Effects such as these are not readily apparent by a casual inspection of the vege tation. In Wilson Canyon are a number of shrubby associations undisturbed by the 1966 Loop Canyon Fire which are clearly seral, having developed in the last 1J'to 20 years, a period in which all of the canyon has been denuded by 3 separate and closely spaced fires, 1956, 1960, and 1962, each destroy ing a major portion of watershed. Nine associations, all of them chaparral, sagebrush-chaparral, and sagebrush, and 92 representing large expanses of the canyon, contain as domi nants or co-dominants; at least J, and probably 4 species considered seral. These are Salvia mellifera, Ceanothus crassifolius, C. oliganthus, and Adenostema fasciculatum, all of which have been reported to reproduce from abundant seedlings following fire. 2 In addition, Salvia mellifera and Ceanothus crassifolius are associated dominants, respec tively, in 6 and 7 other shrub associations. It is obvious from examination of the spatial impor tance of these dominant, seral species that much of the present vegetation patterning and composition is in an early to moderate age of succession, resulting from the fires of the last twenty years. This vegetation will undergo con tinuing changes in the future years, probably as a seral vegetative type responding to repeated patterns of fire at different time intervals. The occurrence of Pseudotsuga macrocarpa is an area of chaparral dominance at first appears to be an anomaly. However, this conifer owes its existence here to the occur rence of fire and the ability of this species to occupy dif ferent habitats from those of chaparral. Pseudotsuga macro carpa is adapted to fire nearly as well as most chaparral species, being able to resprout vigorously, and at times requiring fire to aid in its regeneration. This is ac~om plished because burning establishes conditions optimal for sprouting of Pseudotsuga macrocarpa seedlings by eliminating competitive understory shrubs and preparing the seedbed.J 93

Pseudotsuga macrocarpa experiences fires neither as intense nor as frequent as does chaparral because this conifer occupies steep, unstable, rocky sites. Intense fires would certainly eliminate Pseudotsuga macrocarpa. Thus an equilibrium is established between habitats of Pseudotsuga 'macrocarpa and chaparral species, one in which a certain, limited amount of burning promotes the exis tence of this tree.

Land Use and Vegetation Various aspects of land use affecting the distribution of vegetation are represented in the canyon either from for mal management programs of government agencies, economically related activities of individuals, past settlement, or from incidental activities of recreationists. These aspects are: (1) access roads, (2) firebreaks, (3) conifer planta tions, (4) flood control dams, (5) shrub clearance by pri vate parties, (6) former occupance sites, and (7) hiking and motorcycle trails.

Access Roads The construction of access roads by the United States Forest Service has resulted in the destruction of natural vegetation and its replacement by a seral vegetation of sub shrubs and annual grasses and forbs immediately adjace.1t to the roadsides. A distinctive strip on both sides of the roads is shown on the vegetation map. 94

Firebreaks

Clearance programs by the Forest Service resulted in

the destruction of natural vegetation and its replacement

by sparsely vegetated surfaces. Seeding prescriptions administered to these areas of annual and perennial grasses and forbs assures a regrowth to reduce erosion and because

of lower biomass, reduce fire intensity.

Conifer Plantations

One plantation of Pinus coulteri referred to in chap

ter III has been successfully established in an area from which chaparral was cleared. Successful implantation of

this conifer could possibly lead to further planting of similar plantations in other high altitude portions of the

canyon deemed satisfactory for its growth.

Flood Control Dams

Flood control dams are present in several places in the lower reaches of the canyon. Their construction has resulted in flat, debris-filled basins which have buried shrubs and trees present prior to construction and conse quent earth fill and which are presently occupied by scat tered weedy annual species or seedlings and shrubs of var ious riparian species.

Shrub Clearance by Private Parties

In the vicinity of one large woodland dominated by 95

Quercus agrifolia in the southern portion of the canyon are several areas cleared by mechanical equipment. These areas serve as sites for several commercial beehive colonies. Little vegetation occupies these sites and is comprised chiefly of scattered weedy annuals such as Brassica genicu lata, Erodium cicutarium, Ambrosia acanthicarpa, Amaranthus albus, and occasional sagebrush seedlings.

Former Occupance Sites Sites of former occupance are marked by weedy annuals as well as introduced species, the latter including euca lyptus (Eucalyptus sp.), peach (Prunus persica), periwinkle (Vinca major), an Oenothera species of probable Mexican origin, Bermuda buttercup (Oxalis ~-caprae), redwood (Sequoia sempervirens), incense cedar (Calocedrus decurrens), and olive (Olea europaea).

Hiking and Motorcycle Trails Snakelike patterns of coalescing and crisscrossing lines along ridges and through heavy brush are hiking and motorcycle trails. The most apparent result of trails such as these is the destruction of shrub vegetation along the right-of-way and its replacement by barren ground and scat tered weedy annuals. Motorcycle trails established by "dir.;bike" enthusiasts are of particular severity, often being banked in an obstacle course fashion and resulting in severely eroded ground on steeper portions. Destruction of vegetation is total on these particular routes. 96

Summary Physical factors of climate, terrain, and lithology interacted to produce varied habitats which were responded to by the developing plant cover. Environmental conditions of the Mediterranean climatic regime of coastal southern California produced broad patterns of vegetation dominated by broadleaf, sclerophyllous trees and shrubs and marcescent subshrubs. Subtler differences in composition and physiog nomy mapped during the course of this study are associated with observed variations in terrain and geology. The vegetation of Wilson Canyon has been strongly affected by fire and cultural factors which result in the degeneration of the vegetation to seral forms, outright destruction, or in some cases, replacement by introduced species. Much of the destruction is merited for fire and flood control purposes. In other cases, especially with a recreational activity such as motorcycle riding, the destruction of vegetation is unwarranted and should be con trolled as stringently as possible. Though experiencing drastic cultural affects, the vegetation of Wilson Canyon may be considered as "wildland" vegetation, one which appears to be resilient and able to sust2in itself under various land use pressures and the effects of repeated fires. 97

NOTES

1united States Forest Service, Angeles National Forest-Tujunga District Headquarters, Fire Atlas. 2Ted Hanes, "Succession After Fire in the Chaparral of Southern California," Ecological Monographs 41 ( 1971): 27-52. )Richard Vogl, "Fire Adaptations of Some Southern California Plants," Proceedings of the Tall Timbers Fire Ecology Conference 7 ( 1967): 93. APPENDIX I

LIST OF SPECIES Botanical Name Family Common Name Symbol Arboreal

Acer macrophyllum 1 Bigleaf Maple Am Alnus rhombifolia 6 White Alder Ar Calocedrus decurrens 13 Incense Cedar Cd Eucalyptus sp. 27 Eucalyptus Esp. Juglans californica 22 California Walnut Jc Olea europaea 28 Olive Oe Pinus coulteri 33 Coulter Pine Pic Platanus racemosa 34 Sycamore Pr Populus fremontii 43 Fremont Cottonwood Pf Prunus persica 42 Peach Pp Pseudotsuga macrocarpa 33 Bigcone Spruce Pm Quercus agrifolia 19 Coast Live Oak Qa Quercus chrysolepis 19 Canyon Live Oak Qch Sequoia sempervirens 47 Coastal Redwood Ss Umbellularia californica 24 California Laurel Uc Shrub Adenostema fasciculatum 42 Chamise Af Arctostaphylos glandulosa 16 Eastwood Manzanita Agl Arctostaphylos glauca 16 Bigberry Manzanita Ag Artemisia californica 5 California Sagebrush Ac Baccharis glutinosa 5 Seep Willow Bg Baccharis pilularis ssp. 5 Coyote Brush Bpc consanguine a Brickellia californica 5 California Brickell- Be Brush Ceanothus crassifolius 41 Hoaryleaf Ceanothus Ccr

98 99

Ceanothus leucodermis 41 Chaparral Whitethorn Cl Ceanothus oliganthus 41 Hairy Ceanothus Co Cercocarpus betuloides 42 Mountain Mahogany Cb Corethrogyne filaginifolia 5 Cudweed-Aster Cfp var. peirsonii Eriodictyon crassifolium 21 Thickleaf Yerba Ec Santa Eriogonum fasciculatum 37 California Buckwheat Ef Eriophyllum confertiflorum 5 Golden Yarrow Eco var. confertiflorum Gnaphalium californicum 5 Cudweed Gc Gnaphalium microcephalum 5 Cudweed Gm Gutierrezia bracteata 5 Matchweed Gb Haplopappus parishii 5 Parish Goldenbush Hpa Haplopappus palmeri ssp. 5 Palmer Goldenbush Hp pachylepis Haplopappus squarrosus 5 Sawtooth Goldenbush Hsq Helianthemum scoparium 11 Rushrose Hs Heteromeles arbutifolia 42 Toyon Ha Lepidospartum squamatum 5 Scalebroom Lsq Lonicera subspicata var. 9 Southern Honeysuckle Lsj ,johnstonii Lotus scoparius 18 Deerweed Ls Malocothamnus fasciculatus 26 Bush Mallow Mf Mimulus longiflorus 45 Southern Monkey Ml Flower Nicotiana glauca 46 Wild Tree Tobacco Ng Keckiella cordifolius 45 Climbing Penstemon Kc Prunus ilicifolia 42 Holly-Leaved Cherry Pi Quercus dumosa 19 Scrub Oak Qd Quercus wislizenii var. 19 Scrub Interior Live Qwf frutescens Oak Rhamnus ilicifolia 41 Red berry Ri Rhus laurina 3 Laurel Sumac Rl Rhus ovata 3 Sugarbush Ro Ribes malvaceum 44 Chaparral Currant Rm Rubus sp. 42 Blackberry Rsp. Salvia apiana 23 White Sage Sa 100

Salvia mellifera 23 Black Sage Sm Salix spp. 43 Willow Sx. Sambucus mexicana 9 Elderberry Sme Senecio douglasii 5 Bush Groundsel Sd Solanum xanti 46 Chaparral Nightshade Sxa Symphoricarpos mollis 9 Spreading Snowberry Smo Toxicodendron diversilobum 3 Poison Sumac(Oak) Td Trichostema lanatum 23 Wooly Blue Curls Tl Yucca whipplei 25 Spanish Bayonet Yw Herbaceous

Amaranthus albus 2 Tumbleweed Aa Ambrosia acanthicarpa 5 Sand-Bur Aca Artemisia douglasiana 5 Ad Avena barbata 35 Slender Oat Ab Brassica geniculata 8 Wild Mustard Bge Bromus diandrus 35 Ripgut Grass Bd Bromus mollis 35 Soft Chess Bm Bromus rubens 35 Red Brome Br Chaenactis glabriuscala 5 Cg Chenopodium album 10 Pigweed Ca Chlorogalum pomeridianum 25 Soap Plant Cp Clarkia unguiculata 29 Farewell-to-Spring Cu Claytonia perfoliata var. 39 Miners' Lettuce Cpe perfoliata Convovulus arvensis 12 Bindweed Car Croton californicus 17 Croton Cc Crypthantha muricata var. 7 White Forget-Me-Not Cm jonesii Datura meteloides 46 Jimsonweed Dm Dudleya spp. 14 Live-Forever Dsp. Elymns condensatus 35 Giant Wild Rye Elc Eriogonum elongatum 37 Ee Erodium cicutarium 20 Filaree Eci Erysimum capitatum 8 Wallflower Eca Eschscholzia caespitosa 32 California Poppy Esc 101

Gilia splendens 36 Gilia Gs Hemizonia £asciculata· 5 Tarweed Hf Heterotheca grandiflora 5 Telegraph Weed Hg Hordeum leporinum 35 Hare Barley Hl Lathyrus sp. 18 Pea Lsp. Lotus strigosus 18 Birds' Foot Trefoil Lst Lupinus hirsuitissimus 18 Lupine Lh Lupinus latifolius var. 18 Lupine Ll latifolius Lupinus truncatus 18 Lupine Lt Malocothrix saxatilis var. 5 Cliff Aster Mst tenulfolla Marah macrocarpus 15 Wild Cucumber Mm Marrubium vulgare 23 Horehound Mv Melica imperfecta 35 Coastrange Melic Mi Mimulus brevipes 45 Mb Mimulus cardinalis 45 Me Nemophila sp. 21 Nsp. Oenothera sp. 29 Osp. Oxalis pes-caprae 30 Bermuda Buttercup Op Paeonia californica 31 Peony Pe Penstemon grinellii ssp. 45 Pg grlnellll Phacelia sp. 21 Psp. Pityrograma triangularis 40 Goldenback Fern Pt var. triangularis Poa scabrella 35 Pine Bluegrass Ps Polypodium californicum 38 Polypody Pea Pteridium aquilinum var. 40 Bracken Pap pubescens Salvia columbariae 23 Chia Se Solidago californica 5 Goldenrod Sea Stachys albens '23 Hedge-Nettle Sal Stephanomeria virgata 5 Milk Aster Sv Typha latifolia 48 Cat-Tail Tla Vinca major 4 Periwinkle Vm 102

Zauschneria californica 29 California Fuchsia Zc ssp. californica

--List of Families 1. Aceraceae 25. Liliaceae 2. Amaranthaceae 26. Malvaceae 3. Anacardiaceae 27. Myrtaceae 4. Apocynaceae 28. Oleaceae 5. Asteraceae 29. Onagraceae 6. Betulaceae 30. Oxalidaceae 7. Boraginaceae 31. Paeoniaceae 8. Brassicaceae 32. Papaveraceae 9. Caprifoliaceae 33. Pinaceae 10. Chenopodiaceae 34. Platanaceae 11. Cistaceae 35. Poaceae 12. Convovulaceae 36. Polemoniaceae 13. Cupressaceae 37. Polygonaceae 14. Crassulaceae 38. Polypodiaceae 15. Cucurbitaceae 39. Portulaceae 16. Ericaceae 40. Pteridiaceae 17. Euphorbiaceae 41. Rhamnaceae 18. Fabaceae 42. Rosaceae 19. Fagaceae 43. Salicaceae 20. Geraniaceae 44. Saxifragaceae 21. Hydrophyllaceae 45. Scrophulariaceae 22. Juglandaceae 46. Solanaceae 23. Lamiaceae 47. Taxodiaceae 24. Lauraceae 48. Typhaceae APPENDIX II

ASSOCIATIONS AND COMPONENT STANDS The following is a list of the 19 associations and the stands which have been included in each association. The category of sparsely vegetated surfaces and its component units are also listed. Each species is represented by its letter symbols found in Appendix I alongside its scientific and common name. Ba, a category representing barren or sparsely vegetated surfaces, and listed in much the same manner as species, was used extensively during field mapping

,_ to represent sparsely vegetated surfaces present within vegetative stands. Slash marks were used to separate the categories of dominants and co-dominants, associated dominants, subdominants, and associated species. Within woodland stands, the first species listed on the left are dominants or co~ dominants; species to the right of one slash are associated dominants; species to the right of two slashes are subdomi nants; all species to the right of three slashes are asso ciated species. Within shrub, mixed lifeform, and grass stanJs, subdominants were not recognized. Dominants and co-dominants are listed on the far left; species to the right of one slash are associated dominants; all species to the right of three slashes are associated species.

10J 104

Numbers refer to individual stands which were mapped in the field and which have been retained in field notes. ·

Pinus coulteri Association

L50. Pic/// Af Agl Cb Gr Pg Qwf Pseudotsuga macrocarpa Association

96. Prn Qa/ Qch Pr// Cb Ha Rl 131. Pm/ Qa Qch/// Am Cb Co Dsp. Gr Ha Sm Uc Quercus agrifolia-Q. chrysolepis Association 39. Qa// Ac/// Af Ef Elc Gr Ls Qd Ri Rl Sa Sd Sm Yw J1. Qa// Ac Ef Gr/// Agl Cb Ls Mv Ri Sme Sxa 239. Qa// Cl/// Af Ccr Pi Qd Ro Sm 144. Qa// Co Ha Ri/// Af Cb Cp Ec Eco Elc Gr Ha Hsq Mm Qd Ri Ro Sxa 18. Qa// Gr/// Elc Ha Ls Mm Rl Sm 32. Qa// Gr Td Vm///Ad Ha Mv Ng Op Pp Pr Ri Rl Sme Ss Sxa 23a. Qa// Gr Rl/// Ac Af Eco Ef Ls Sm 153· Qa// Gr Rl/// Ec Eco Elc Ha Kc Ml Pea Sx. Sxa Td 58. Qa// Ha Ri Rl Sx./// Ac Ad Af Be Bd Br Ccr Ec Eco Ef Ml Ng Qd Sm Sme Sxa Td Yw 52. Qa// Ha Rl 20. Qa// Ha Rl Ro/// Ad Ag Agl Ccr Co Ec Eco Ef Elc Ls Ml Mm Ng Qd Sm Sme Sxa Td 73a. Qa/// Ad Ll Ng Pap Pr Rl Sx. 1. Qa// Rsp./// Ac Ad Bpc Ec Ef Elc Lsq Mv Ng Pf Pr Rl Sm Sx. Td 119. Qa/ Qch// Elc Gr/// Af Ag Cb Ccr Cl Co Ha Jc Ll Pi Qd Ri Rl Ro Sm Td Uc Yw 117. Qa/ Co Ha Sme/// Af Agl Br Ccr Cpe Eca Eco Ef Ll J.lf.m Sa Sx. Td Yw 42. Qa Esp.// Ac Ec Ef/// Ls Mv Ri Ro 75. Qa Qch/// Ac Ad Am Ar Ec Ha Me Rl Sal Sea Sme Td 225b. Qc Qch/// Af Ccr Elc Pr Sd Uc 87. Qa Qch/ Am/// Ad Af Be Bd Ccr Ec Eco Ef Me Ng Rl Rsp. Sal Sea Sd Td 105

8?a. Qa Qch/ Am Uc/// Ac Bd Br Ng Rsp. Td 33. Qa/ Rl///.Ac Gr Mv Ng Sm 12a. Qa// Ha Rl/// Ccr Ro Sm Sme Sx, 15b. Qch// Cb Ha Rl/// Af Ccr Ef Elc Sm Sx. Td 129. Qch Qd/ Ha Qa/// Af Cb Co Ri Rl Ro Sm

Salix ~· Association 32a. Sx./ Bg/// Ac Ad Me Pf Sal Sea Sd 49b. Sx./// Ad Bg Ec Gr Me Pr Qa Sal Sea Sme

Arctostaphylos ~.-Ceanothus ~.-Quercus ~· Association 165a. Agl/// Af Ccr Cl Ef Hs Yw 180b. Agl Af/ Ba Ccr Ec/// Ag Cl Co Ls Qwf Yw 214. Agl Ccr Cl/ Af/// Ag Ec Eel Mm Pi Ro Ro Yw 168b. Agl Ro/// Af Ccr Co Ec Sm Tl Yw 242. Ccr Cl/ Ba Ec Sm/// Cb Qd Ml 246. Ccr Cl/ Af Sm/// Ha Pi Qwf Ro Yw 179. Ccr Cl Co/ Af Ro Sm/// Ag Ec Ha Qd Qwf Ri 108. Ccr Co/ Af Sm/// Cl Ec Eco Ef Ha Mm Pc Qd Ro Sme Tl Yw 14. Ccr Co Qch/ Qa/// Af Ag Agl Ha Ri Ro Sm 140. Cl/ Co Qd Qwf Ro/// Af Agk Ccr Qa Sm 217. Cl/ Af Agl Ccr Qwf// Ag Ec Qd Ri Ro Sme Td 236. Cl/ Ccr Ha Qa Ro/// Af Cb Eco Ml Qwf Sm 108a. Cl Co/ Ccr Ec/// Ml Mm Qa Qd Qwf Td 148. Cl Co/ Af Qwf/// Ag Agl Ls j Qd Ri Ro 143. Cl Co Af/// Ag Ccr Ha Qa Qd Qwf Ri Ro Sm Yw 139. Cl Co Ro/ Qc Qch Sx./// Af Ccr Elc Lsj Pr Qd Sm Sme Smo Yw 219a. Cl Qwf/// Af Ccr Ec Ro 168. Co/ Ccr Ha Qd/// Af Ec Mm Pi Ri Ro Td 171. Co/ Agl Ccr/// Af Cl Ec Hs Qd Ro Sm Yw 11J. Co Ha/ Cb Qa Qd/// Af Ccr Ec Ef Mm Ri Rl Ro Sm 164. Co/ Af Qwf/// Ag Agl Ccr Cl Ec Ha Hpa Hs Qd Rm 175. Co Qd/ Cl/// Af Agl Ec Ha Qa Ro Sm 184. Co Qwf/// Af Ec Ha Ml Ro Sme 123. Co Sm/ Af Ccr/// Cl Ha Rl Ro Sme 106

238. Co Sx./ Ccr Cl Hall/ Af Pr Qa Qch Ro Sm 128. Qa Rol Co. Qd/// Af Ag Ccr Cl Ec Elc Ls liJT_m Sm 170. Qdl Cl Co Rolli Af Ec Mm Sm 180a. Qwf Ro/ Aflll Agl Ccr Cl Co Qd Sm 148a. Qwf Af/ Cl Co/I I Ag Agl Qd Ri Td Ceanothus crassifolius Association 6. Ccrl Ac SmlI I Cb Ec Ef Ha Qd Ri Rl Ro 147. Ccr/ AflI I Ag Agl Cb Cl Ec Ha Qd Qwf Ri Ro Sm Yw 178. Ccrl Af Agl Clll/ Ba Co Ec Qd Ro Yw 218. Ccrl Af Agl Cl Qd Qwfl// Ec Eco Ef Mm Rm Ro 189. Ccrl Af Ba Ec/11 Ef Ls Qa Rl Sm Yw 249. Ccrl Af Ba Ec//1 Ag Agl Cl Qwf Ri Ro Sm Yw 138. Ccrl Af Cl Co Smlll Ec Qd Ro 231. Ccrl Af Cl Sm/1/ Ag Cb Ha Mm Qa Rl Ro Yw 243. Ccrl Af Cl Smlll Agl Ha Qa 213. Ccrl Af Ec//I Ag Agl Cl Ef Ml Qwf Ro Sm Tl 191. Ccrl Af Ba Cb Ec/11 Ec Gr Rl Ro Sm Yw 105. Ccrl Af Ec Sm//I Agl Ef Ls Ml Rl Ro Sc Yw ?d. Ccrl Af RllI/ Ef Sm Yw 8b. Ccrl Af RllI I Ef Sm Yw 15. Ccrl Af Rl Sm/I I Agl Cb Ec Eco Ef Qa Ro Tl Yw 90a. Ccr/ Af Sm/I I Ec Ef Rl Ro Sm Yw 115. Ccrl Af Sm/I/ Agl Cl Co Ec Ef Rl Ro Yw 125a. Ccri.Af Smlll Cl Co Yw 132. Ccr/ Af Sm/1/ Cl Co Ec Ha Mm Rl Ro Sme 135. Ccr/ Af SmlI I Ag Br Cl Ml Mm Qd Ro 142. Ccrl Af Smll/ Ag Cl Co Qd Qwf Ro 187. Ccrl Af Sml// Ec Ef Ls Rl Sme Yw 235. Ccr/ Af Sml/I Agl Cl Ec Ef Qa Qd Tl Yw 221. Ccrl Cl Ec Qwfl// Ro Sd Sm Yw 191 b. Ccr/ Ec Sm/// Af Ha Ro Sme 192. Ccrl Gr Sm/// Af Ec Ef Mm Rl Ro Sme Yw 233- Ccrl Rl SmlI I Af Ag Cb Ha Qch 227. Ccrl Sml// Af Ec Ef Cl Pi Pr Qa Rl Ro Yw 223. Ccr Ba/ Af Sm/I/ Agl Ec Ef Qwf Ro Yw 107

6b. Ccr Bal RllI I Af Cb Ec Ef Ha Sm Yw 227a. Ccr Gr/ Smlll Af Agl Ls Ml Ro 11a. Ccr Rl/11 Af Ec Ef Ha Sm Sme Adenostema fasciculatum-Ceanothus crassifolius Association 182. Af Ccrlll Ag Agl Cb Cl Co Ec Ls Qd Qwf Sm Yw 172a. Af CcrlI I Ag Agl Cl Co Ec Sm Yw 176. Af Ccrl AgllI I Cl Ec Ro Sm Yw 219. Af Ccrl Agllll Cl Ec Ls Qd Qwf Ro Yw 215. Af Ccrl Agl Cll I I Ag Ef Qwf Ro Yw 106. Af Ccrl I I Agl Ec Ef Ls Sm Yw 222. Af Ccrl Ba Cl Eclll Agl Ml Ro Sd Sm Yw 195. Af Ccrl Ba Ec SmlI I Ag Agl Cl Ec Ha Ls Pi Rl Yw 206. Af Ccrl Cllll Ag Cb Ec Ha Qd Sme Td Yw 210. Af Ccrl Ecl I I Ag Agl Cl Ef Hpa Ls Qwf Ro Sm Yw 204. Af Ccrl Ec EflI I Ag Agl Gr Hpa Ls Pr Ri Sm 8. Af Ccrl SmlI I Cb Ec Ef Ha Pi Ro Yw 8a. Af Ccrl Smlll Rl Yw 14a. Af Ccrl Smlll Agl Ccr Ha Ls Qa Sd Sxa Tl 95. Af Ccrl Smlll Agl Cb Ef Ha Qa Qd Rl 104. Af Ccrl Sml I I Agl Ec Ef Ha Rl Yw 173· Af Ccrl Smlll Agl Cl Qd Ro 2JJa. Af Ccrl Smlll Ag Cb Ha Qch Rl Adenostema fasciculatum Association 67. Afl Ac EflI I Hsq Rl Sm Yw 180. AflI I Ag Agl Cb Ccr Cl Ec Ef Ha Ls Ml Qd Qwf Ri Ro Sm Yw 127. A£111 Ag Ccr Cl Ls Mm Qd Qwf Ro Sc Ri 214a. Afl Ag CliiiEc Eco Mm Pi Ro Yw 2J5a. Afl Ba Ccrlll Cl Eco Qd Sd Yw 149. Afl Ba Cl Co Qwflll Ccr Qa Sm Yw 176a. Afl Ba Cl QwflI I Agl Ccr Co Ec Hs Ro Sxa Yw 20a. Afl Ba E£111 Agl Ccr Ec Eco Ha Ls Rl Sd Sm Tl 172. Afl Ba E£111 Agl Ccr Cl Ec Hs Sm Yw 146. Afl Ba GrlI I Agl Ccr Ec Ef Ro Sm Yw 212. Afl Grill Ag Agl Ccr Cl Ec Eco Ef Hpa Ls Sm Sme 108

174. Afl Ba HslI I Agl Ccr Cl Co Ec Ef Ls Qd Ri Ro Sm Tl Yw 165. Afl Ba Hs. Qctlll Ccr Cl Ec Ef Ls Sm Yw 169. Afl Ccrlll Cl Co Qd Ro Sm Yw 185. Afl Ccr Cllll Ag Co Ec Qwf Ro 191a. AfI I I C cr E c E f Gr R 1 S d Sm 93. Afl Ccr Rl SmlI I Ec Ef Gr Ng Rl Sa Yw 22. Afl Ccr Smlll Ac Cb Ef Ha Qd Ri Yw 136. Afl Ccr SmlI I Cl Co Ef Ha Qd Ri Rl 141. Afl Ccr Smlll Agl Cl Co Ef Qa Qwf Ro Yw 84b. Afl Ef Grill Rl Sm Yw 85. Afl Ef Grill Ccr Ha Qa Rl Yw 141a. Afl Qalll Cl Co 69. Afl Sm/I I Ef Hsq Ls Tl Yw 115a. Afl Smlll Agl Ba Ccr Hs Qd Yw 137. Afl Smlll Ccr Cl Co Qd Yw 43a. Af Acl Gr Ls Smlll Ef Rl Yw 7. Af Balli Cb Ccr Ec Ef Rl Sa Sm Yw 216. Af Bal CcrlI I Agl Cb Ec Eco Ml Yw 232. Af Bal CcrlI I Cb Ef Rl Sm Yw 247. Af Bal Ccr Smlll Cl Ro Yw 180c. Af Eel Agl Ba Cll/1 Co Qd Qwf Yw 168a. Af Eel Co QdlI I Cb Ccr Ha Ro 248. Af Grl Cb CcrlI I Ag Agl ClEf Qd Qwf Ri Ro Sm Yw 41. Af Rllll Ac Ls Sm Sme Yw 43. Af Rll/1 Ac Ls Sm Sme Yw Cercocarpus betuloides Association 25c. Cbl Ac AfllI Ef Gr Sm Yw 3· Cbl/I Ac Af Ef Ng Sa 102c. Cbl Ccr Gr Rllll Af Pi Qd Sm 164a. Cbl Co Qwf HoiI I .\f Ccr Cl Ec Ha Hs 19J. Cb Ccrl Af Sm Qdl/1 Ag Agl Ec Ha Mm Qa Qch Ri Rl Ro Sme Yw 191c. Cb Ha Rllll Af Ccr Ec Qa Qch Sm Sme 229. Cb Smlll Af Ccr Ec Ef Ls Rl Yw 109

Eriodictyon crassifolium-Heteromeles arbutifolia Association

130. Ec Ha Qd Rl/// Af Agl Cb Ccr Cl Co Qch Ri Ro 121. Ec Ha Ro/// Af Ccr Cl Co Qch Ri Ro 91. Ha Ccrl Af Ec Sml// Cb Qa Ri Rl Ceanothus crassifolius-Salvia mellifera Association

225. Ccr Sm/// Af Cl Ec Pi Pr Qa Rl Ro Yw 8d. Ccr Sm/ Af//I Agl Ef Ha Rl Ro Yw 16. Ccr Sm/ Af/// Agl Ef Ha Rl Ro Yw 111. Ccr Sml Af//I Cl Ec Ef Ha Mm Qd Rl Ro Yw 112. Ccr Sm/ Af//I Co Ec Ef Ha Mrn Qch Rl Ro Yw 234. Ccr Sm/ Af//I Cl Ec Ef Pi Yw 190. Ccr Sm/ Af Ec/// Ha Qch Ro Sd Sme Yw 199. Ccr Sm/ Af Grl// Agl Ec Ef Elc Ls Pi Rl Ro 237. Ccr Sm/ Af Gr/// Cl Ec Ef Pi Yw 91. Ccr Sm/ Af Ha//1 Cb Qa Ri Rl 13. Ccr Sm/ Af Ha Rl/// Agl Ec Ef Ng Pi Rl Ro Adenostema fasciculatum-Salvia mellifera Association 188. Af Gr Sm/ Ec/11 Ccr Eco Qa Rl Yw 181. Af Sm/// Ag Agl Cb Ccr Cl Ec Ha Qd Qwf Ro 167. Af Sm/// Agl Ccr Cl Co Ls Qd Qwf Ro Sc Yw 107. Af Sm/ Ba/// Agl Ccr Co Ec Ef Ha Rl Ro Yw 5c. Af Sm/// Cb Ec Ha Rl 4b. Af Sml Ccr/// Ef Rl Yw 124. Af Sm/ Ccr/// Agl Cl Co Mm Qd Rl Ro Sme 177. Af Sml Ccr/I/ Agl Ec Qwf Ro Yw 126. Af Sm/ Ccr Ec/11 Agl Cl Co Mm Qa Rl Ro Yw 211. Af Sm/ Ccr Eclll Ag Cl Ls Pi Ro Sd Yw 8c. Af Sm/ Ccr Rll// Ec Ef Pi Ro Yw 18c. Af Sm/ Ec//1 Agl Ccr Co Ha Qch Rl Ro Yw 84a. Af Sml Ec/// Ccr Ef Rl Yw 194. Af Sm/ Ec Gr/1/ Agl Ccr Ef Ha Ls Ro Tl Yw 134. Af Sm/ Gr/// Ag Ba Cb Ls Ml Qd Rl Sc Sxa 13a. Af Sm/ Ng//I Ccr Ef Rl 110

Adenostema fasciculatum-Ceanothus crassifolius-Salvia mellifera Association

57a. Af Ccr Smlll Ac Ha Qa Rl Yw lJJ. Af Ccr SmlI I Ag Ec Mrn Rl Ro Yw 220. Af Ccr Smlll Agl Cl Ec Pi Qwf Yw 166. Af Ccr Smlll Cl Co Qd Qwf Ro 225a. Af Ccr Smlll Cl Ec Pi Pr Qa Rl Ro Yw 114. Af Ccr SmiGrlI I Agl Cl Co Ec Ef Mm Rl Ro Sxa Yw --Rhus laurina Association 80. Rllll Ac Af Ec Eci Qa Sm Yw 49a. RllI I Ac Elc Gr Sm 16b. Rll Ccr SmlI I Ef Yw J6a. Rl Af/ SmlI I Ccr Eci Ef Qa Ri Sd Sme Td Yw ?a. Rl Bal Ccr Ec EflI I Af Cb Ro Sa Sm Yw 5. Rl Ba/ Eflll Ac Af Cb Ccr Ec Eci Ha Sa Sc Sm Yw 16c. Rl Ba/ Ef Sml I I Ccr Sa Yw 102a. Rl Ccrl SmlI I Af Cb Ec Ef Gr Qd ?e. Rl Ha/ CcrlI I Af Ec Ef Sm Yw Salvia mellifera Association 57. Sml Ac Af Ccrl/1 Cb Ha Hsq Ls Ri Rl Yw 62. Sml Ac RllI I Af Ec Ef Sme Yw 17a. Sml AflII Ccr Ec Ef Ha Qa Rl 66. Sml AflI I Ac Ccr Ef Ha Qa Rl Ro Sa Yw 145. Sml Aflll Ccr Cl Ec Qd Ro 125. Sml Aflll Agl Ccr Cl Co Mm Qd Yw 100. Sml Aflll Ef Rl Yw 5b. Smlll Af Cb Ccr Ef Gr Ha Rl Sa Yw 84. Sml Af CcrlI I Ac Ec Ef Ha Qa Rl ?6. Sml Af Ccrlll Ac Gr Rl Sme 245. Smlll Cb Cl Ha Ro Yw 240. Sml Af CcrlI I Cl Ec Ef Pi Pr Qa Rl Ro Yw 105a. Sml Af CcrlI I Ec Ef Rl Ro Yw 5a. Sml Af Ccr EflII Ec Rl Yw 111

6c. Sm/// Af C cr E f R 1 Yw 19b. Sm/// Af Ccr E f R 1 Yw 102b. Sm/// Af Ccr Mm R1 Ro 241. Sm/ Af Gr/// Ag1 Ccr Ef Ls M1 Sd 122. Sm/ Af C1 Co/// Ag1 Ccr Ec Ha Mm R1 Ro 4. Sm/ Af Ef R1/// Ac Cb Ccr Ec Ha Yw 228. Sm/ Ccr/// Af C1 Ec Ef Pi Pr Qa R1 Ro Yw 102. Sm/ Ccr/// Af Ec Ef Ha R1 Yw 109. Sm/ Ec/// Af Cb Ccr Co Ef R1 200a. Sm/ Ec Ef/// Ac Af Cb Ccr R1 101. Sm/ Ec R1/// Ac Af Cb Ccr Ef Ha Ro 57b. Sm/ Ef Ls/// Ac Af Ccr Ec Hsq Sd 110. Sm Ba/ Gr R1/// Ac Cb Ccr Co Ec Ef Sa Yw 29b. Sm Ec/// Ac Af Ccr Gr Ls Lsq Sa Yw 198. Sm Ec/ Af Ccr/// Ag Ag1 Ef R1 195b. Sm Ec/ Ba/// Ccr Ef R1 Yw 18a. Sm Ec/ Ccr Ef/// Af Ccr Eco R1 Sxa Yw J6. Sm Ec/ Ef/// Ac Ccr Lsq Qa R1 Sd Sme 15a. Sm Ef/// Af Ccr Ec R1 Yw 68. Sm Gr/ Ac Sa/// Af Ef Yw 230. Sm Gr/// Af Ag Ccr C1 Ec Ha R1 Yw 103. Sm Gr/// Cb Ccr Ec Qa R1 Sm 97. Sm Gr/ Ec Ef/// Af Ag1 Ccr Eco Ha Hsq Rl Ro Yw 62b. Sm R1/ Ac Sa/// Af Ccr Ef Gr Yw 59. Sm Rl/ Af/// Ac Ccr Ef Yw 36e. Sm Rl/ Ec Ef/// Ac Ccr C1 Ng Pr Sa Sd Sme Sx. Yw Artemisia californica-Salvia me1lifera Association

24. Ac Sm/ Af Ef/// Mv Ng R1 Sm Yw 81. Ac Sm/// Af Ef Qa Rl Sa Yw 60. Ac Sm/ Ef Gr R1/// Ccr Ec Ls 30. Ac Sm/ Gr Ls/// Af Ef Yw

Artemisia ca1ifornica-Eriogonum fasciculatum-Annua1 Grass Association

48. Ac/// Af Ccr Co Ls Ri R1 Yw 70. Ac/// Af Ec Ef Gr Ha Hsq Mf Mi Ps Ri Rl Sa Sme 112

?4. Ac/// Af Ef Gr Ha Qa Rl Sm 29a. Ac/ Ba Gr/// Ec Ls Ng Qa Sd Sm Sme 35b. Ac/ Be Ec/// Eco Ef Ls Ml Mv 4?a. Ac/ Ec/// Ef Elc Lsq Pr Rl Sa Sd Sm Sme Sx. Yw 28b. Ac/ Ec Sm/// Af Cb Ccr Ef Ng Rl Sa Yw 25e. Ac/// Ec Ef Hsq Lsq Ng Sd Sm Sme 2. Ac/ Ef Gr Sm/// Af Ccr Ec Qa Sa Sme Yw 25a. Ac/ Gr/// Af Ef Ha Sm 51. Ac Af// Ec Ef Rl Sa Yw ,46. Af Ec/ Ef/// Ccr Hp Lsq Rl Sa Sm Sme Sx. 47. Ac Ec/// Ef Elc Lsq Pr Rl Sa Sd Sm Sme Sx. 55. Ac Ec/// Ef Elc Gr Lsq Ng Rl Sd 37. Ac Ec Ef/ Sd Sm/// Gr Lsq Mf Ng Ri Rl Sme Sx. 56. Ac Ec Ef/ Gr/// Af Rl Sa Yw 49. Ac Ec Rl/// Af Cl Co Ef Gr Ls Mf Ng Pr Sa Sme Sx. 45. Ac Ef/ Ec Hp/// Af Ccr Eco Ls Lsq Ng Qa Rl Sm J8. Ac Ef/// Ec Sa J4. Ac Ef/ Ls Sm/// Cb Ccr Ec Rl Sa Yw 28. Ac Ef Gr/// Af Ccr Ec Ng Rl Sm Yw 25. Ac Gr/ Af/// Cpe Ec Ee Ef Gb Ha Mi Ps Rl Sm Sv Yw 41. Ac Gr/ Af Ef/// Cfp Ec Ha Ro Sm Yw 25d. Ac Gr/// Af Ef Ls Qd Sm Sme Sv Yw 154. Ac Gr/ Ec/// Af Ef Ng Qa Rl Sa Sm Sx. Yw 28a. Ac Gr/ Ef Ls/// Af Ccr Ng Rl Sm Yw 65. Ac Gr/ Ef Sa/// Af Hsq Rl Sm Yw 36c. Ef/ Ec Rl/// Ac Af Ccr Lsq Ng Pr Qa Rl Ro Sd Sm Sme Yw

150 I Ef Gr/ Af Rl Yw/// Ac Cfp Ls Sm 40. Ef Gr Sa/// Ac Ccr Yw

Adenostema fasciculatum-Eriodictyon crassifolium-Eriogonum fasc:culatum-Annual Grass Association

66a. Ac Af Ef/// Sm 158. Af Ec Ef Gr/// Ccr Rl Sm Yw 10a. Af Ef/// Ccr Ec Sm Yw 161. Af Ef/ Gr/// Ccr Ec Eco Ls Rl Ro Sm Tl Yw 113

54. Af Ef/// Gr Yw 23. Af Ef Bai.Gr Sm/11 Ccr Hpa Rl Yw 4a. Af Ef Grl/1 Ac Ccr Rl Sm Yw 9a. Af Ef Grl/I Ccr Sm 18b. Af Ef Grl Ccr Sm/// Rl Yw 12. Af Ef Gr/ Hs Ls/11 Ccr Ro Sm Yw 17. Af Ef Gr/ Ls Sm//1 Ccr Ec Rl Tl Yw 208. Af Grl Cl Ec/// Ag Ccr Eco Ef Ha Ls Ml Pr Qd Ro Yw 61. Af Gr/ EfllI Ac Ls Rl Sd Sm Yw 50. Af Gr/ Ls/// Ac Eco Ef ·Rl Sm Yw 162. Ba Ec Ef/ Af Gr/// Ccr Eco Ha Rl Tl Yw 29. Eel Ac Gr Ls/1/ Af Ccr Ef Lsq Mf Ng Rl Sd Sm Sme 207. EelI I Af Ag Ccr Cl Ef Ls Ro Sd Sm Yw 88. EelI/ Af Ba Ccr Ef Rl Sa Sm Yw 163. Eel Af Ccrl// Ef Gr Ha Qa Rl Sm Yw 157. Eel Ba Ef Gr/1/ Ac Af Ccr Eco Ls Rl Sm Yw 72. Eel Gr Rl/// HaNg Sa Sme Sx. 207a. Ec Ef//I Af Ccr Ml Yw 205. Ec Ef/ Ccr//I Af Rl Sm Tl Yw 36d. Ec Gr//I Ac Af Ccr Eci Ef Lsq Ng Qa Rl Sme 159. Ec Gr/ Af Ccr Rl/// Ef Elc Sm Yw 64. Ef Grl// Ac Af Ha Qa Rl Sm Sme 73. Ef Gr/ Af Ec/// Ac Ha Rl Sa Yw 23b. Ef Grl Af Sa/I/ Hpa Rl Sm Yw 120. Ef Grl Eel// Af Agl Bge Car Cl Cm Co Cu Eci Gc Hg Ls Lst Lt Mb Ng Sm Yw 155. Ef Grl Af Ec Rl/// Ccr Ha Ng RoSa Sm Yw 89. Ef Gr/ Rll// Af Cb Sa Sm Yw 195a. Ef Gr/ Sml// Af Ccr Ef Pi Ro Yw 90. Ef Sml Afl// Ccr Rl Sa Yw 196. Gr Ls/ Sml// Af .Agl Ccr Ec Eco Ef Pi Rl

Annual Grass Association

186. Grl Ac/11 Af Eco Ef Ha Rl 70b. Grl AflI I Af Ef Rl Sme Yw 25b. Grl Ac Af/// Ef Mi Ps Sm Yw

I / 114

152. Grl Ac Af EelI I Cfp Eco Ef Ha Hsq Ls Ml Qa Ri Rl Yw 77. GrlI I Ac Af Ccr Cg Cm ·Ec. Eco Ef Hf Ls Mst Rl Sa Sm Yw 27. Grl Ac Ec Eflll Rl Sm Yw 44. Grl Ac Ec Eflll Af Ls Rl Sa Yw 71. Grl Ac Ec EflI I Af Cm Eco Mm Rl Sa Sc Td Yw 9. Grill Af Agl Ccr Ef Ls 160. Grl Af Ec EflI I Ccr Cg Cm Eco Hf Ls Mst Rl Ro Sm Yw 209. Grill Af Bg Ccr Ec Ef Gs Pg Qd Yw 224. Grill Af Ccr Ec Ef Ls Sd Sm 84c. Grl Af EflI I Ccr Rl Sa Sm Yw 92. Grl Af Eflll Ec Rl Sa Yw 19a. Grill Af Ef Qa Rl Sm 98. Grill Af Ef Qa Rl Sm Yw 10Jb. Grl Ba Cb Rl Smlll Af Ccr Ec Ef Ha Qch Qd 76a. Grl Ba Smlll Ac Af Ef 78. Grl Cb Rllll Af Ec Ef Mm Ng Qa Sa Sm Yw 18). Grill Ccr Cl Ec Qwf Ro 20). Grl Ec Eco LsiI I Af Ag Ccr Cl Ef Ha Mm Pi Pr Qa. Qd Ro Sd Td Yw 21. Grill Ef Yw 26. Grl Eflll Ac Af Ec Mi Ps Rl Sm Yw 118. Grl Elc LllI I Eca Ef Ls Mi Sa Sd Sxa 94. GrI LsiI I A c E f Ng R 1 Sm 200. Grl SmlI I Af Cb Ec Ha Qch 8). Gr Balli Ac Af Ec Ef Ha Ri Rl Sm Yw 86. Gr BalII Ac Af E c Ef Qa Rl Sm Yw J6b. Gr Balli Ac Ef Qa Rl Sm 17b. Gr Bal RllI I Af Ccr Ef Sm Yw Sparsely Vegetated Surfaces 29c. BalII Ac Cb Cc Ec Ef Hsq Lsq Mv Ng Sd Sm Sme Sx. 19. Balli Ac Af Cb Ec Gr Ha Qch Rl Sa Sm Yw 79. Balli Ac Af Gr Rl Sa Yw la. BalII Ac Ef Elc Ng Qa Rl Sm 115

?Oa. Bal Ac Ef NglI I Af Ec Ls Lsq Sd 35. Bal Ba Gr.Sx. Tlalll Aa Ac Ad Aca Ca Ccr Cl Ec Eco Ef Hg Ls Me Mv Ng Rl Sv Sxa Sd 82. BalII A c E f N g Qa Sx. 244. BalII Af Ag Ccr C'l Ef Ml Qa Qd Ro Sm 116. Balli Af Agl Ccr Co Rl Sc Sm Yw 202. Balli Af Cb Ef Ha Pm Qa Qch Rl Sm Td 156. BalII Af Ccr Ec Eco Ef Ha Qa Rl Sa Yw 10b. BalII Af E f Gr 53. Bal Af Ef Rllll Ac Ec Sa Sm Yw 11. Bal Af SmlI I Cb Ccr Ec Ef Rl Yw 10Ja. Bal CblI I Ccr Ec Rl Sa Sm Yw 6J. Bal Cb Ec Ha Smlll Ac Af Ef Ri Rl Yw 197. Bal Ccr Ec GrlI I Af Agl Ef Sm Yw ?c. Bal Ec Ef RllI I Af Cb Ccr Ha Sm 99. Bal Ec Ef RllI I Af Ccr Sm J6f. Bal Ec RlllI Ac Ef Lsq Ng Qa Sd Sm Sme Sx. 16a. Bal Ef Gr Rllll Af Ccr Ec Ha Sm Yw 201. Bal Gr Rllll Af Ec Ef Sm 6a. Balli Ac Af Ccr Ef Ha Pi Ri Rl 226. Bal Smlll Af Ccr ClEf Qa Rl Yw 151. Bal Rl Sx.lll Ac Pr Rsp. Sm APPENDIX III

SUMMARIES OF TRANSECT DATA Transect data are summarized for each sampled stand or stands under each method, the Point Centered Quarter Method and the Line Intercept Method, Estimated dominance is also listed for comparison.

Point Centered Quarter Method Stand No. 125, Transect No. 1, 22 Observations Points. Estimated Dominance Average Area by Stratified Code Height Density Sm 4.9' 3,512 - Af- shrubs/acre 0* Agl Ccr Cl Co Mm Qd Yw Relative Relative Species Abundance Frequenc:y % % Salvia mellifera 51.4 90.0 Adenostema fasciculatum 20.9 80.0 Ceanothus crassifolius ?.9 40.0 Eriogonum fasciculatum 5.9 30.0 Yucca whipplei 4.3 30.0 Eriodictyon crassifolium 2.4 15.0 Mimulus longiflorus 1.2 5.0 Ceanothus oliganthus .8 10.0 Salvia apiana .8 10.0 Rhus laurina .4 5.0 Rhus ovata .4 5.0 TOXI:::odendron diversilobum .4 5.0 Ceanothus leucodermis .4 5.0

*No subdominants recorded

116 117

Stand No. 164, Transect No. 2, 25 Observation Points. Estimated Dominance Average Area by Stratified Code Height Density Co 5.9' 5,404 Af Qwf shrubs/acre 0 Ag-Agl-Ccr-Cb Cl- Ec Ha Hpa Hs Qd Rm Relative Relative Species Abundance Frequency % % Ceanothus oliganthus 55.9 87.5 Cercocarpus betuloides 9.3 25.0 Adenostema fasciculatum 9.0 29.1 Ceanothus crassifolius 7.3 29.1 Rhus ovata 4.2 2d.8 QUercus wislizenii var. frutescens 3.8 25.0 Prunus ilicifolia 2.8 12.0 Arctostaphylos glauca 2.4 12.0 A. glandulosa 1.7 8.0 Heteromeles arbutifolia 1.0 8.0 Quercus dumosa 1.0 12.0 Eriodictyon crassifolium . 7 8.0 Ribes malvaceum ·3 4.0 Stand No. 248, Transect No. 3, 20 Observation Points Estimated Dominance Average Area by Stratified Code · Height Density Af Gr 4.8' 1,850 - cb-Ccr- shrubs/acre o Ag-Agl-Cl Ef-Qd Qwf Ri Ro Sm Yw Relative Relative Species Abundance Frequency % % Adenostema fasciculatum 68.3 100.0 Ceanothus crassifolius 8.0 35.0 Yucca whipplei 6.3 35.0. Quercus dumosa 3.8 25.0 Quercus WISIIZenii var. frutescens 3.4 15.0 Arctostaphylos glandulosa 2.4 15.0 Erior;onum fasciculatum 2.1 10.0 Rhamnus ilicifolia 1.7 15.0 Salvia mellifera 1.7 15.0 Rhus ovata .8 5.0 Gereocarpus betuloides .4 5.0 118

Stand No. 15, Transect No. 4, 23 Observation Points. Estimated Dominance Average Area by Stratified Code Height Density Ccr 6.3' 1,523 Af-RI Sm- shrubs/acre o Agl Cb-Ec Eco Ef Qa Rl Ro Yw Relative Relative Species Abundance Frequency % % Ceanothus crassifolius 54.7 100.0 Salvia mellifera 16.7 86;9 Eriodictyon crassifolium 14.8 52.1 Adenostema fasciculatum 6.5 43.5 Rhus laurina 4.J 26.1 ErlOgonum fasciculatum 1.8' 13.0 Rhus ovata 1.1 13.0 119

Line Intercep1 Method Stand Nos. 25, 29, 29a, 28; Transect No. 5; Distance-285'. Estimated Dominance by Stratified Code 25. Ac Gr 29. Ec - Af-- Xc-Gr Ls 0 0 Cpe Ec-Ee Ef-Gb . Af-Ccr-Ef Lsq Ha Mi Ps Rl Sm Mf Ng Rl Sd Sm Sv Yw Sme 29a. Ac 28. Ac Ef Gr -Ba -Gr -- -0--- 0 0 Ee-Ls Ng-Qa Sd Af-Ccr-Ec Ng- Sm Sme Rl Sm Yw Absolute Relative Relative Species Coverage Frequency Abundance % % % Annual Grass* 27.7 78.9 24.8 Artemisia californica 17.4 68.4 21.0 Adenostema fasciculatum 8.0 47.J 8.5 Barren* 7.8 26.J J.4 Eriodictyon crassifolium 6.8 J1.6 9.4 Salvia mellifera 5.8 21.0 4.3 Eriogonum fasciculatum 5.7 15.8 6.8 Rhus laurina 5.3 5.2 .8 LePTdospartum sguamatum 4.1 15.8 5.1 Lotus scoparius J.1 15.8 4.J Yucca whipplei J.O 21.0 4.J Ceanothus crassifolius 2.6 10.5 J.4 Salvia apiana 1.6 15.8 2.6 Haplopappus sguarrosus 1.0 5.2 .8

*Annual grass and barren areas were recorded in the same manner as were species. 120

I I

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