Plant Response Parameters to General Patton's Armored Maneuvers in the Eastern Mojave Desert of California

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8-1979

Randall J. Iwasiuk

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Recommended Citation Iwasiuk, Randall J., "Plant Response Parameters to General Patton's Armored Maneuvers in the Eastern Mojave Desert of California" (1979). Loma Linda University Electronic Theses, Dissertations & Projects. 1037. https://scholarsrepository.llu.edu/etd/1037

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PLANT RESPONSE PARAMETERS TO GENERAL PATTON'S

ARMORED MANEUVERS IN THE EASTERN

MOJAVE DESERT Or CALIFORNIA

by Randall J. Iwasiuk

The purpose of this study, which was undertaken from September,

1977 through June, 1978 was to survey the response of perennial vegetation to General Patton's World War 11 armored maneuvers. This

information will be used to help construct a basis far predicting recovery rates on the effects of off-road vehicle impacts in the California

Desert Conservation Area (CDCA). These impacts were assessed in three usage catagories: tank tracks in the maneuvers areas; roadways, which were used primarily by jeeps and trucks; and tent areas, cleared areas in which tents and other semi-permanent structures were erected. The data generated from these areas was compared to data gathered from adjacent undisturbed control sites.

The methods employed were temporally separated series of aerial photographs analyzed for density and cover, supplemented by on-site ground disturbance and control measurements of these parametes. From these values diversity, stability, productivity, community quality indices, and Jaccard's coefficient of similarity were calculated.

Results indicate that the maneuvers hada negative effect on the perennial vegetation, the degree of impact varying with habitat conditions and the various use catagories. This concentrated, distant past use even with 37 years allowed for recovery still shows an overall mean plant cover reduction of fifty percent. Ground measurements of percent species composition show differences between disturbed and control sites in addition to the reduction in cover indicating an alteration of plant diversity and stability. Both aerial photographic and ground transect analyses indicate a marked reduction of perennial vegetation as a result of the initial maneuvers and a relatively slow recovery rate, varying with use intensity, physiognomic, and topographic characteristics.

Kay words: perennial vegetation responses, General Patton s tank maneuvers sites, aerial photographic analyses, on-site ground transect analyses, density, cover, stability, diversity, productivity, tank tracks, roadways, tent areas, recovery rates. LOMA LINDA UNIVERSITY Graduate School

I· I PLANT RESPONSE PARAfv1ETERS TO GENERAL PATTON'S ARMORED MANEUVERS IN THE EASTERN MOJAVE DESERT OF CALIFORNIA

Randall J. Iwasiuk

A Thesis in Partial Fulfillment of the Requirements for the Degree Master of Arts in the Field of Biology

August 1979 Each person whose signature appears below certifies that he has read this thesis and that in his opinion it is adequate in scope and quality as a thesis for the degree of Master of Arts.

, Chairman Earl W. Lathrop, Associate Pro essor Department of Biology

Conrad D. Clausen, Assistant Professor Department of Biology

. Douglas leman, Associate Professor Depart of Biology ACKNOWLEDGEMENTS

Sincere appreciation is extended to all those who contributed time and effort in helping to make this project a success.

A considerable amount of gratitude is owed to Dr. Earl W.

Lathrop who unfalteringly provided guidance through periods of obscure direction and whose patience with equipment and people will certainly become legendary. Special thanks go also to Al Endo and

Dr. John Adams of the Bureau of Land Management who provided physiognomic data on the study sites. •

Recognition and thanks is due also to Loma Linda University,

Department of Biology for the use of facilities and equipment and also to the BLM for their financial assistance in the form of grant WCA-060-RFP7-26.

Favorable acknowledgement is made to Candy Horsley for her assistance. in the field and also to Dean Clayton and Bob Styles for their company on field trips.

lii

TABLE OF CONTENTS

I. • INTRODUCTION'. . . • . • . •c • • . • • . • • • • • 6 . 1

II. STUDY SITES • . e • • 0 • • 0 • A • 9 2

A. Site Selection • • .• • • . • . • 0 • 2

B. Site Description' ...... 2

TIT. PROCEDURES . a 0 • • 0 • • • • • • • • • •

A. Aerial Photographic Analyses • • • • • • A • • •

B. On-site Ground Analyses • • • • 0 • • * • 18

C. Statistical Considerations . * • . 21

IV. RESULTS a • • 6 • • • • 0 21

A. Camp Ibis

1. Aerial photographs • • • • • • • • 21

2. Ground transects ...... • . • • , 9 • a i 0 • 22

B. C miEssex

. 22 I. Aerial photographs . • . 6 . . 0 • • 2 • 2 9

2, Ground transects . . . . „ . . • • . 0 37

C. Diversity • • . . . 6 •...... • • . . . . . * 37

52 D. Stability • • • • • • • • • • 0 0 0 4 • 0

E. Productivity . • • . • • • •

V.. DISCUSSION/CONCLUSIONS • • . • • • • • 0 4 • 0 • 60.

VI. LITERATURE CITED . . •. 4,1 6 . • • 78

APPENDIX A. . Plant List. - • $ •

APPENDIX B. 6 • Formulae/Calculations • • °

APPENDIX C. Aerial Photograph Carbrat ons 0 • • • • • 84

LIST OF TABLES

Table 1. Summary data of physiognomic characteristics for

Camps Ibis and Essex . . . • . e • • • Table 2. Density and mean percent cover from 1953 and 1974

aerial photographs of Camp Ibis . • • • • 27

Table 3. Density and cover means from ground transects at

Camp Ibis . • • • • • • • • • • • •

Table 4. Relative cover (% composition) and total percent

cover from ground transects at Camp Ibis • 35

Table 5. Density and mean percent cover from 1953 and 1974

aerial photographs of Camp Essex . • . • .

Table 6. Density and cover means from ground transects at

Camp Essex • • . • o .. . e a 48

Table 7. Relative cover (% composition) and total percent

cover from ground transects at Camp Essex • • 50

Table 8. Diversity measurements. Richness, e uibility

evenness, and diversity indices for Camps Ibis

andEssex . • . • ...... ,_c'.

0 Table . Community Quality Indices (CQI) for perennial

vegetation at Camps Ibis and Essex . 4 0 6 6 6 55

Table 10,, Jaccard s Coefficient of Similarity (CCj) for

pairs of transects at Camps Ibis and Essex . . , . . 57 Table 11. Summary of use intensity comparisons in the CDCA . LIST OF FIGURES

Fig. 1. Location map of the Eastern Mojave Desert showing

Camps Ibis and Essex . • • • 0 . . . . 4

Fig. 2. Bar graph showing density of perennial vegetation

Iron aerial photographs taken in 1953 and 1974 of

Camp Ibis . • 4 0 4 • 23 Fig. 3. Bar graph showing mean percent cover of perennial

vegetation from aerial photographs taken in 1953

and 1974 of Camp Ibis . • 11 • • • • • • • 4 . L.5

Fig. .4. Bar graph showing density of perennial vegetation

from ground transects at Camp Ibis . . • ...... 29

Fig. 5. Bar graph showing cover and mean cover of perennial

vegetation from ground transects at Camp Ibis . . 31

Fig. 6. Bar graph showing density of perennial vegetation

from aerial photographs taken in 1953 and 1974 of

Camp Essex . . . • . • • • •• • . . • • • • 38

Fig. 7. Bar graph showing mean percent cover of perennial

vegetation from aerial photographs taken in 1953

and 1974 of Camp Essex . •

Fig. 8. Bar graph showing density of perennial vegetation

from ground transects at Camp Essex . . • . . • • • 44

Fig. 9. Bar graph showing cover and mean cover of perennial

vegetation from ground transects at Camp Essex . • . • 46

Fig. 10. Bar graph showing percent change of perennial veg-

etation in relation to disturbance intensity from

vi aerial photographs taken in 1953 and 1974 of

Camp Ibis . . . . • 61

Fig. ii, Bar graph showing percent change of perennial

vegetation in relation to disturbance intensity

from aerial photographs taken in 1953 and 1974

of Camp Essex . . . . • . 63

Fig. 12. Bar graph showing percent change of perennial veg-

etation in relation to disturbance intensity from

ground transects at Camps Essex and Ibis . . . . 65

Fig. 13. Bar graph showing successional recovery of peren-

nial vegetation between 1953 and 1974 in relation

to disturbance intensity at Camps Ibis and Essex . 67

Fig. 14. Bar graph showing comparison summaries of mean

percent change in relation to disturbance in-

tensity for study areas in the CDCA . . • . • • 76

vii LIST OF PLATES

Plate 1. Photograph showing tank tracks at Camp Ibis . . . • 8

Plate 2. Photograph showing tank tracks on desert

pavement at Camp Essex . . . • . • . • . .

Plate 3. Photograph showing tank tracks on desert

pavement at Camp Ibis 6 • • • • ...... 10

Plate 4. Photograph showing roadway at Camp Ibis...... 10

Plate 5. Photograph showing roadway with an adjacent

tent area at Camp Essex ...... •. . • . • . . 12

Plate 6. Photograph showing a tent area at Camp Essex . . .. . 12

Plate 7. Photograph showing a headquarters site at

• Camp Essex . • • 0 a . , lb. • • . • . . . . 14

Plate 8. : Photograph showing undisturbed control site

nearCamp Essex . . . . • . • . . • • ...... 14 :

Plate 9. Photograph showing undisturbed control site

near Camp Ibis . • . • . • . • 9 • • • *.. , 16

Plate 10. Photograph showing undisturbed control site

near Camp Ibis . . e, • • . • • • • • • • • • • • . . 16

viii I. INTRODUCTION

General Patton's armored maneuver areas were studied for the purpose of surveying recovery rates of perennial plants in order to help predict the effects of current off-road vehicle use in the California

Desert Conservation Area (CDCA). This information will help federal land managers make more informed decisions on .how to allocate lands of the CNA. for various uses.

Objectives of the study were to:

1. Identify the type of disturbance.

2. Determine the type of plant response to the disturbance.

3. Determine the time required for favorable response to various

types of disturbance.

4.„Determine the relation between intensity of disturbance and plant

response.

This study consisted of two phases. First, aerial photographs were analyzed to determine recovery rates between 1953 and 1974 at the sites which were disturbed by Patton 's maneuvers from 1938 to 1942. The second phase of the study was an on-site ground analyses of differences between the disturbed sites and control sites to detect the extent of recovery from the original disturbance over a period of approximately

37 years. Measurements of the ground transects were made approximately in the same locations as the aerial photographic analyses. The undisturbed control transects were measured in close proximity to the test sites of the same community which had similar physiognomic and topographic characteristics. _These analyses permitted a comparison of recovery between 1953 and 1974 for the aerial photographs and recovery between

1942 and 1977 for the ground transect sites. Because of the differences in methods between the aerial photographic analyses and the on- site ground analyses direct comparisons can not be made. However, similar trends in the results of the two methods are readily observable

11. STUDY SITES

A. Site Selection

The two study sites were Camp ibis, approximately 32 kilometers northwest of Needles, and Camp Essex, approximately 4.5 kilometers north of Essex, San Bernardino County, California (Fig. I). These sites were• selected in consultation with the Desert Plan Staff of the Bureau of

Land Management (BLM). The armored training areas were selected to provide data on heavily concentrated, past use characteristics and recovery of representative vegetation.

B. Site Description

The easternMojave Desert where, this study was conducted consists of a gravelly alluvial substrate With a rather gentle slope At an elevation between 1,600 and 2,100 feet (Table 1). The prevalent vegetational community type is the Creosote bush scrub, dominated by Larrea trl- deptata (Thorne, 1976). This dominant community thrives in areas that receive usually 2-6 inches of rain per year and have a wide.. range of diurnal and seasonal temperatures. Although Larrea tridentata- sometimes occurs in purestands as the only perennial shrub- in an area, it is 3

usually associated with such perennials as Ambrosia dumosa, Atriplex spp.,

Encelia farinosa, Hymenoclea salsola, and various species of cacti such

as Opuntia and Echinocereus (Munz, 1965).

On-site ground photographs were taken at both study sites illustrat-

ing the various disturbance and control transects (Plates 1-10).

III. PROCEDURES

•A. Aerial Photographic Analyses

Study sites for transect plots were located on aerial photographs.

for all test sites and control areas. Test site selection on the photo-

graphs required criteria such as homogeneity of the vegetation, presence

of a specific disturbance type (tank tracks, roadway, tent or utility

areas), and the presence. of a high proximity, vegetationally equivalent,

undisturbed area for a control. Aerial photographs were calibrated by

comparing exact ground and aerial distances between known landmarks.

Transparent grid plot overlays were then calibrated from horizontal dist-

ance ratios for each photograph (Appendix C) in order to measure total

density and cover of perennial vegetation in the test and control plots.

To measure total density the transparent grids were placed over the

test and control sites and the and the number of shrubs visible through .

a sandard stereo viewer were counted within transect plots.(K). Density

was calculated with standard formulae using the photograph and grid cal-

ibrations previously mentioned. Density was expressed as number/plot,

or more accurately as no/.12 or .04 ha, depending on th:e:. calibration

ratio of the photograph. Though resolution was poor at high magnifications Fig. 1. Location map of the Eastern Mojave Desert of California

showing the two armored maneuvers sites studied (stipled

areas). Camp Ibis is located approximately 32 km north-

west of Needles, California and Camp Essex, approximately

4.5 km north of Essex, California. 58 Barstow

Camp Victorville Essex 0 Essex

Los Angeles San Bernardino 62 Twenty Nine Table 1. Summary data of physiognomic characteristics for Camp Essex, T 8N, R 21E, Sec. 28 (tank tracks), and T 8N, R 16E, Sec. 11 (all other sites), and Camp Ibis, T 11N,

R 21E, Sec. 28 (tank tracks), T ION, R 21E, Sec. 18 (roadway and tent area), and

T ION, R 20E, Sec. 20 (control). SUMMARY DATA

Sites Essex Ibis

Physiognomic

Characteristics

Elevation 2020 feet 1680 feet

Slope/Aspect 2-3% NW 1% SE

Parent rock mixed alluvium mixed alluvium

Land form alluvial fan alluvial plain

Surface conditions 90% gravel-pavement 80-90% gravel-pavement

Soil consistency soft, very friable slightly hard, very friable

Dry, moist, wet slightly sticky slightly sticky

slightly plastic slightly plastic

Soil texture

surface loam loam

subsurface variable, gravely, rocky sand gravely, sandy loam

Soil structure

surface moderate, med. platy moderate, med. platy

subsurface single grain massive - - Plate 1. Photograph showing tank tracks in camp Ibis, T I1N, R 21E,

Sec. 28. Photograph by R. Iwasiuk, January 29, 1978.

Plate 2. Photograph showing tank tracks,on "desert pavement" in

Camp Essex, I 8N, R 21E, Sec. 28. Photograph by R.

Iwasiuk, December 18, 1977.

41~.-

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- •••••-! • ' •••••••;: • ••• • h. A•;,.! - IPf L • _ Plate 3. Photograph showing tank tracks on "desert pavement in Camp Ibis, T IIN, R 21E, Sec. 28. Photograph by R. Iwasiuk, January 29, 1978.

Plate 4— Photograph showing a roadway in an armored maneuvers area in Camp Ibis, T ION, R 21E, Sec. 18. Photograph by R. Iwasiuk, January 29, 1978. .

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(within the lines of rocks at the left) in Camp Essex,

T 8N, R 16E, Sec. 11. Photograph by R. Iwasiuk, Dec-

ember 18, 1977.

Plate 6. Photograph showing a tent area in Camp Essex, T 8N, R 16E,

Sec. 11. Photograph by R. Iwasiuk, December 18, 1977. A Plate 7. Photograph showing a headquarters site in a tent area in

Camp Essex, T 8N, R 16E, Sec. 11. Photograph by R. Iwasiuk,

December 18, 1977.

Plate 8. Photograph showing undisturbedcontrol site in a Creosote

bush scrub community adjacent to disturbed sites in Camp

Essex, T 8N, R 16E, Sec. 15. Photograph •by R. Iwasiuk,

March 19, 1978.

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bush scrub community (note area of desert pavement) adjacent

to.. Camp ibis, T 10N, R 20E, Sec. 20. Photograph by R.

Iwasiuk, January 29, 1978.

Plate 10. • Photograph showing undisturbed control site adjacent to .

Camp ibis, T ION, R 20E, Sec. 20. Photograph by R. Iwasiuk,.

January 29, 1978. - - _

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of the photographs, there was good agreement between the trends observed in the aerial photographic measurements and the ground transect results.

The sample size for the study sites is indicated by K and N (numbers of individuals) in the tables of results.

Cover was measured by observing an aerial photograph through a

Bausch and Lomb filar micrometer eye-piece attached to the stereoscope.

A moving hairline calibrated in increments of .001 micrometer units was used to measure vegetation on the micrometer line transects. The hairline of the micrometer was placed directly beside a shrub, which appeared as a small dot touching the transect line. The micrometer reading was recorded, and then moved to the opposite side of the shrub and this second value was recorded. The sum of all these shrub widths is the total vegetational distance for the transect line (K). The sum of the vegetational distance was divided by the length of the transect line (1000 micrometer units) and multiplied by 100 to give the relative cover on each transect line. While it was impossible to detect and measure every shrub that is visible on a comparable ground transect, the photographic analysis.tended to give trends in the results similar to those of the on- site ground measurements.

B. On-site Ground Analyses

On-site ground transects were measured in approximately the same locations as the aerial photograph transects. Test site selection criteria was identical to that of test site selection for the aerial photographs. Because species were readily identifiable on. the ground, percent composition tables were also prepared.

The ground transects were measured for density and cover of per- 9

ennial vegetation in the various disturbance sites and also in a comp-

arable nearby control site. The point-quarter method (Brower and Zar,

1975) was used. A minimum of 32 random points (K) along a line was

,sampled for each disturbance type and control. In the case of the road-

way transects, the point-to-plant distance was taken from the nearest

shrub in the roadway or its immediate influence (the berm along the side),

not the closest shrub in each of the four quadrats formed by the point,

as was done for all other point-quarter transects. Density and cover

was calculated from the field data using standard formulae for such cal-

culations (Appendix B).

Diversity of perennial shrubs in disturbed and control transects

was calculated from values of density as evenness (V), diversity index

(DI), equibility (Ec ), and richness (R). Richness is the number of

species present in the test transect. Evenness is a measure of how

equally the species are represented in the transect. This was expressed

by Hurlbert (1971) and Johnson, et al., (1975) as d d min - d max - d min • The d is the observed diversity, d min and d max, the minimum and

maximum diversities respectively, as calculated according to the index

•of McIntosh (1967). The values for V range from 0 to 1. The greater the

number the more even the number of individuals represented are in each

site.

To obtain d, the diversity index (DI) was calculated as proposed by

McIntosh and Johnson, et al.: 20 in which N is the total density (cover or biomass may also be used) for individuals of all species (s) present in the sample and ni the value for each species. The values for d range from zero. The greater the value of d, the greater the variety of species. Minimum diversity was calculated as N d min = (S - 1) where N is the total density, n is the number of individuals, and S is the number of species. Maximum density was determined as

d max = N

Equibility, basically another measure of evenness, is given by

Whittaker (1975) as

cz E = c (log d max- log d min) The values for Ec range from zero. The greater the value of Ec, the more equible or evenly represented are individuals in each test site.

Stability of perennials in the on-site ground transects was esti- mated from cover in relation to relative age span, by comparing similarity between transects and by an estimate of community quality. Relative age span divided into long-lived perennials (a) and (SO are based on the catagories assigned to many desert species by Vasek, et al., (1975a,

1975b) and Johnson, et al., (1975).

To determine community quality, the Community Quality Index (CQI) as proposed by Vasek and Johnson, et al., (1975) was used. This formula is expressed as % ground covered by x % total perennial CQI = LL perennials ground cover This index integrates an estimate of productivity, in this case plant cover, and an estimate of relative community age, the percentage of 21

ground covered by long-lived species. Values for CQI range from zero.

The greater the number, the more stable long-lived perennials there are in a community and the fewer exotics and weeds there are present.

Transect similarity was compared by Jaccard's coefficient of community similarity (CCj) as proposed by Brower and Zar (1977), and Vasek, et al., (1975a), and is expressed as

CCj = 2 Sl S2 - C where S1 and S2 are the percent cover in transects I and 2 respectively, and Cis the total percent cover common to both transects. Values for

CCj range from 0 to I. Generally a similarity coefficient of'about .7 or higher indicates virtual identity between communities.

C. Statistical Considerations

Limited statistical analyses were made for the transects both on the ground and on the aerial photographs. The point-quarter method and the line transect method of the on-site ground measurements do not lend themselves to an evaluation of means. Mean and standard error of the mean

(s-) was determined for aerial photograph density and cover measurements.

IV. RESULTS

A. Camp Ibis

1. Aerial photographs

A general similarity between the values for density and cover is

readily observed. Fig. 2 shows that changes in density over the 21 year

period are most pronounced in the tent area and control transects while

the tank track transects show a slight negative change in density, and 22 the roadwaytransects only a slightly positive change in density. Fig. 3 shows significant increases in mean percent cover in tank track and roadway transects while showing little to no change in cover for tent area and control transects Table 2 provides the actual values for density and cover for these transectmeasurements along with the standard error of the mean. 2. On-site ground transects The similarity between the values for density and cover that were pointed out previously for the aerial transect analyses can be seen in the graphs of density and cover of the ground transects. Although the values can notbe directly compared to the aerial results, similar trends between the two groups of data are readily observed. In Fig.. 4 the tank track and roadway transects show density levels distinctly Tower than tent area and control transect densities. Fig. 5 shows the .greatest differences between the total cover and the mean cover per individual in the tank track and roadway transects while the ratio between total and mean individual cover for tent area and control transects is small. Table 3 provides a summary of density and cover values for the Camp Ibis ground measurements. Table 4 shows relative cover expressed in termsof percent composition and the total percent cover for each transect. B. Camp Essex 1. Aerial photographs The similarity between values for density and cover of aerial measurements described for Camp Ibis (Figs. 2 and 3) is shown in the aerial measurements for Camp .Essex. Fig. 6 shows that the changes in Fig. 2, Bar graph showing density, (no/.12 ha) of perennial vegetation measured

from aerial photographs taken in 1953 (0) and in 1974 ( ) of Camp

Ibis. Density, (no/.12 ha)

C31 **.4 00 kr) CD, i V (A) -Pt. CTI CT

t ti

oasue. 1953 sq ,Tank Tracks 1974

oadway 1953 1974

Tent Area 1953 1974

1953 1974 Fig. 3. Bar graph showing mean cover, (%) determined from line transects of aerial

photographs taken in 1953 (E) and in 1974, ) of Camp Ibis. Cover, (%

IN) 01 01 D 01

DOSUP, Tank Tracks 1953 S4 1974

1953 1974

1953 1974 Table 2. Density, (no/.12 ha) and mean cover, (%) determined from transect plots (K)

on 1953 and 1974 aerial photographs of Camp Ibis.

Density, (no/l2 h I Site 1953 1974 1953 1974 (st,) Tank tracks 120 1374 11.45 1.094 120 1352 11.27 0.539 50 87 10.93 0.732 50 115 15.09 0.974 Roadway 120 78 .65 0.248 120 121 1.01 0.265 104 14 1.36 0.157 104 41 3.48 0.552 Tent area 120 975 8.12 0.*81 120 1100 9.17 1.071 50 76 11.53 1.882 50 102 13.31 1.397 Control 120 1708 14.23 0.265 120 1891 15.76 1.003 50 137 20.13 2.595 50 144 20.19 1.994 Fig. 4. Bar graph showing density, (no/ha) of perennial vegetation for ground transects

at Camp Ibis. Transects taken on January 29, 1978. Density, no/ha

N.) 01 CD C.71 CD CD

ti UP. DDS SI. Fig. 5. Bar graph showing total cover, (m2/ha) (1173) and mean cover, (m2/individual) ( "

of perennial vegetation in ground transects at Camp Ibis. Transects taken January

29, 1978.

Cover, ( m2/110

i--, ND CO -4. CTI 01 ....4 03 CD CD CD CD CD CD CD C:o CD CD CD CD

11 UP.

00S Tank Tracks S4,

Mean cover, (m2/1-ndividua1) Table 3. Density and cover means for perennial vegetation at Camp Ibis. Ground transect

plots (K) measured on January 29, 1978. Site K N Densit Cover, ( /h )

Tank Tracks 32 128 1290.7 264.6

Roadway 32 128 744.5 118.9

Tent Area 36 144 2196.3 414.7

Control 32 128 2032.3 746.9 Table 4. Relative cover, (% composition) and total percent cover of perennial vegetation

on ground transects at Camp Ibis. Transects taken on January 29, 1978.

Camp Ibis Relative Cover

Creosote bush scrub 'Sites

Species N Tank Tracks N Roadway N Tent Area N Control

Ambrosia dumosa 69 23.08 F14 45.08 105 59.34 73 26.94

Brickellia incana 29 21.87 17 13.57

Krameria parvifolia 8 4.47 .33

Echinocactus polycephal6s .31

Eriogonum fasciculatum 2 2.16

Hymenoclea salsola 1 .04 1 2.1

. Larrea tridentata 47 68.91 12 30.64 16 31.01 51 71.89

Lycium cooperi .37

Opuntia ramosissima 3 3.50 2 .84

Stephanomeria pauciflora 2 .31 2 .24

Total cover ...... 2.65 . 1.19 ... 4.15 ...... 7.47 .. 37 density are again greatest in the tent area and control, transects while the tank track and roadway transects exhibit slight differences in density over the 21 year period. The transects in Fig. 7 all show distinct increases in mean cover and do not appear to fit the pattern described for Camp Ibis. The values for density and cover ditermined from aerial analyses are shown in Table 5.

2. On-site ground transects•

The similarity between density values for ground transect measurements in Fig. 8 follows the pattern discussed for the ground transects in Camp Ibis (Fig. 4) in that the tank track and roadway. transects again show the lowest density. The density of perennial shrubs in Fig. 8 is, however, significantly lower than the density for tank track ground measurements in Camp Ibis. Fig. 9 displays a pattern described for -

Camp Ibis. Tank track and roadway transects show the greatest difference between total cover and mean individual. cover. The ratios in total and mean individual cover in tent area and control transects, however, do not correspond to the values shown for ground transects in Camp Ibis.

The ratio between total and mean individual cover for the tent area transects is more like.the ratio observed in the roadway transects. In the control transects the relationship in covers are reversed. Table 6 provides values for density and cover means from ground transects. Table 7 • gives •relative cover in terms of percent composition and total percent cover for each of the ground transects.

C. Diversity

Table 8.shows the results of diversity measurements calculated from the data of the ground analyses in Camps Ibis and Essex. In both study Fig. 6. Bar graph showing density, no/.12 ha) of perennial vegetation measured from

aerial photographs taken in 1953 (0) and in 1974 ) of Camp Essex. Density, ,(no/.12 ha)

I-1 I-4 ui oo k.o cp.

L - _ _.407ipassimomlirriairriar1merrouriwoliamminve lui asu o

sl. 1953 1974

Roadway 1953 1974

1953 1974

1953 1974 Fig. 7. Bar graph showing mean cover, (%) determined from line transects of aerial

photographs taken in 1953 (E:3) and in 1974 ) of Camp Essex. Cover, (%)

1953 1974

1953 1974 Table 5. Density, (no/.12 ha) and mean cover, (%) determined from transect plots K)

on 1953 and 1974 aerial photographs of Camp Essex.

Densit‘ Cover

-Site K N 1953 1974 1953 1974 (s5z)

Tank tracks 120 985 8.21 0.886

120 968 12.23 1.214

50 86 10.97 1.056

50 91 12.23 2.547

Roadway 120 177 1.47 0.169

120 219 1.82 0.161

100 IA .77 0.679

100 33 2.31 3.145

Tent area 120 1027 7.20 0.694

'20 864 8.56 1.304

50 62 7.22 0.747

50 85 10.76 1.817

Control 190 1278 10.65 0.871

120 1276 10.60 1.502

50 134 18.06 1.688

50 147 1937 1.009 FIg. 8. Bar graph showing density, (no/ha) of perennial vegetation for ground transects

at Camp Essex. Transects taken on December 18, 1977 and on March 19, 1978. Density, (no/ha)

cz) 0-1 U,.%D czo • c) - Cis C) C)

Ai P.

0eSU Tank Tracks S1. Fig. 9. Bar graph showing total cover, (m2 /ha) (E:3) and mean cover, (m2 /individual of perennial vegetation in ground transects at Camp Essex. Transects taken on

December 18, 1977 and on March 19, 1978. sl.pasueJi Mean cover,m CA) cD

Cover, (m CD cD

2 iindlvIdual) 2 01 cD /ha

. 00 CD Table 6. Density and cover means for perennial vegetation at Camp Essex. Ground transect

plots (K) measured on December 18, 1977 and on March 19, 1978. Site K N DensitY, (no/ha) Cover, (m2/ha)

Tank Tracks 30 120 803.1 307.4

Roadway 24 96 820.4 170.3

Tent Area 34 136 1202.2 449.4

Control 32 128 2644.7 892.6 Table 7. Relative cover (% composition) and total percent cover of perennial vegetation

on ground transects at Camp Essex. Transects taken on December 18, 1977 and

on March 19, 1978. Camp Essex Relative Cover

Creosote bush scrub Sites

Species Tank Tracks Roadway Tent Area N Control

Ambrosia dumosa 19 11.70 74 53.75 86 42.99 95 41.26

Krameria parvifolia 2 .22

Larrea tridentata 94 86.94 22 46.25 49 56.79 32 34.72

Opuntia basilaris 2 .18

Opuntia ramosissima 3 .95

Stephanomeria pauciflora .22 1 4.01

Total cover % • .• . 3.07 ...... 1.7 4.49 8.93 ... 06 52

areas the number of species (R) is greater in all transects than in the control transects for all but one transect group (Camp- Essex, roadway).

For Camp ibis equibility (E0) values are similar between transectsind-

icating that the species represented in the transects are approximately

equally distributed. The values for evenness (V) are not as equal in

either study area. It may be difficult to construct an accurate pict-

ure of these two parameters due to the rather low richness in the two

study sites. The same may be said for the diversity index (DI) which*

describes species variety. The results of the diversity calculations

indicate in a general way that richness tended to increase with dist-

urbance intensity; equibility and evenness seemed to remain relatively

unchanged; and the diversity index was decreased.

D. .Stability

• . Table. 9 clearly shows a distinct pattern in Community Quality In-

dex (01) values between transects in both study areas. The values of

CQI decrease with increasing disturbance intensity in both Camps Ibis

and Essex. Table 10 shows Jaccard's coefficient of similarity (CCj)

for pairs of transects. Comparisons between control and roadway •tran-

sects (AID) show the least similarity. The values for CCj decrease

with increasing dis-similarity between the control and disturbed site

transects.

E. Productivity -

The aerial photographic and ground transect density and cover means

for both -Camps - Ibis and Essex were used in estimating productivity which

was expressed as percent change. The values were calculated by the Table 8. Diversity measurements computed from densities, (no/ha) of perennial vegetation

at Camps Ibis and Essex. Calculations based on ground measurements. R = richness

(no. of species); Ec = equibility; V= evenness; DI = diversity index.

Transects

Area Tank Tracks Roadway Tent Area Control Ibis 5 5 7 4

4.00 4.03 4.37 3.01

.600 .514 .363 .589

DI 447.83 222.81 554.89 617.84 Essex 3 3 Ec 4.10 1.38 2.05 .656 .321 .631 DI 160.73 160.67 327.30 Table 9. Community quality indices (CQI) for perennial vegetation at Camps Ibis and Essex.

Calculations based on total percent cover of ground transect measurements. Transects

Area Tank Tracks Roadwa Tent Area Control Ibis 2.6 1.0 3.8 7.5

Essex 3.1 1.7 4.5 8.7 Table 10. Jaccard's coefficient of similarity (CCj) for pairs of transects at Camps Ibis

and Essex. Calculations based on total percent cover of ground measurement

data. A = Control; B = Tent Area; C =Tank Tracks; D = Roadway. Transects Compared

Area A/B A/C A/D Ibis .55 .35 .20

Essex .51 .35 .19 59 formula

control (mean) - test mean) control mean) .

Fig. 10 shows percent change from aerial photographic-transect data for Camp Ibis. The transect catagories are shown in order of in-

-creasing use intensity which does not necessarily correspond to disturbance intensity. The density. in the tank track transects actually shows a positive percent change versus the control for the 1974 aerial photographs. Fig.11 shows, the percent changes in cover and :density means for aerial photographs taken of Camp Essex. No patterns seem to

emerge in the relationship between density and cover from the aerial

photographs. For each parameter, however, it is observed that the 1974 •

photographic analysis show less negative percent change than the 1953

photographic results. One exception is noted for the densitieste-

tween 1953 and 1974 measurements of tank track transects in Camp Essex

(Fig. 11). Fig. 12 gives percent changes from the control means ver-

sus test means for ground transects in Camps Ibis and Essex. An ex-

ception to the trends is seen in a positive percent change for density

in the tent area transects for Camp Ibis. Again disturbance intensity

expressed as negative percent change, is shown in order of increasing

use.intensity. The negative percent changes for cover show a distinct

pattern. for both Camps Ibis and Essex in that a direct correlation is

observed between disturbance intensity and use intensity. Fig. 13 pre-

sents the percent change for the 21 ear period of cover and density for

all transects in Camps Ibis and Essex as determined from aerial photo-

graphic analyses. The percentages of recovery are arranged in order of 60 increasing use intensity. Control transects show the least percent changes while roadway transects show the greatest increases.

It can be seen that productivity can be expressed as negative per- pent change when thought of in terms of reduced density and cover in test transects compared to undisturbed control transects, or as positive percent change when seen in terms of increases of cover and density in transects that have been allowed a period of undisturbed recovery.

V. DISCUSSION/CONSLUSIONS

Although the results of the aerial photographic and on-site ground analyses can not be directly compared, at least one general trend may be observed between the two phases of this study. In both aerial and ground results from both study areas it can be readily observed that density and cover means can be ranked according to disturbance catagory. Road- ways display the greatest reductions in density and cover followed by tank tracks and tent areas. This seems to suggest that even though the margin of error is large in terms of the real densities and covers as they would be determined on the ground, the aerial values are at least consistant among themselves makeing them useful in that they can be use- ed with confidence to predict trends in general results that could be determined by the more accurate ground analyses.

The aerial photographic results also provide information that con- tributes to our understanding of some basic ecological principles. Den- sity and mean percent cover for test and control transects as measured from aerial photographs of Camps Ibis and Essex are shown in Figs. 2,3, Fig. 10. Percent change from control of perennial vegetation in relation to disturbance

intensity at Camp Ibis as determined from aerial photographic analyses of den-

sity (0) and cover ( ) for the years 1953 and 1974. Disturbance intensity

is represented in order of increasing use intensity by tent area (1), tank

tracks (2), and roadway (3). f7L6 1. £961. tiL6 £961.

L6 I £961.

f7/6 1. e £961. nc ba tur is D

tiL6 £96 I fiL6 £961.

C) CD (2) C.) CO (NJ r-- a6uPqo % Fig. 11. Percent change from control transects of perennial vegetation in relation to

disturbance intensity at Camp Essex as determined from aerial photographic

analyses of density (0) and cover ( ) for the years 1953 and 1974. Dist-

urbance intensity is represented in order of Increasing use intensity by tent

area (1), tank tracks (2), and roadway (3). 100

1 2 3 Disturbance intensity Fig. 12. Percent change from control transects of perennial vegetation in relation to

disturbance intensity at Camp Essex (A) and Camp Ibis (B) as determined from

ground measurements of density (0) and cover ( ). Disturbance intensity

is represented in order of increasing use intensity by tent area (1), tank

tracks (2), and roadway (3). 100

(1) cr) = 20

100

3 2 3

Disturbance intensity Disturbance intensity Fig. 13. Successional recovery of perennial vegetation between the years 1953 and 1974

in relation to disturbance intensity at Camp Essex (A) and Camp Ibis (B) as

determined from aerial photographic analyses of density (0) and cover (0).

Disturbance intensity is represented in order of increasing use intensity by

control (1), tent area (2), tank tracks (3), and roadway (4). 2001

100-

100 3

A Disturbance intensity Disturbance intensity 69

6, And 7. Changes in density over the 21 year period are slightly negative in tank track transects from both Camps Ibis and Essex. Roadway transects show only a slight increase in both study areas. This observation suggests that disturbance in these transect sites reduced perennial vegetation' density by completely destroying many individuals, Even over a 21 year period of observed recovery the number of individuals in these two use type transects show a net gain in density of approximately zero. This may be due to the fact that building roadways and repeated passage of heavy equipment (tanks etc.) eliminates individuals and alters the substrate by the removal and/or the compact- ion of topsoil. This reasoning seems to be supported by two factors. One, density increased significantly in the tent area transects for both study sites, and even the control transect densities in Camp Ibis displayed a significant increase over the 21 year span. Assuming that the control and tent area transects did not undergo substrate alteration to the extent that t e tank track and roadwaytransects did this observation may be expected. The second factor in support of the altered substrate hypothesis is shown in observing the significant increases in mean percent cover in tank track and roadway transects while showing little or no change in cover for tent area and control transects (Fig.3). This observation is in accord with the altered substrate concept in that while there was little or no change in numbers of individuals over the 21 years in areas of disturbed substrate, the few individuals that sur- vived would be expected to measureably increase the area they cover in these transects, In the transects that underwent less substrate dist 70

urbance (tent area and control transects) numbers of individuals would

• increase but mean percent cover would be expected to -remain relatively

constant due to the biomass carrying capacity of the physical environment.

The mean percent cover values for tent area and control transects at

Camp Ibis *(Fig. 3) seem to support this by indicating through little

cover change that the environment is at its carrying capacity. These

relationships show that severe disturbance prevenes perennials from re-

covering in terms of numbers. The surviving individuals in these

greatly disturbed sites are relieved of competition pressure allowing them

to display large percent cover increases relative to less intensive

disturbance and control sites..

In the case of less Aistrubed sites the reverse seems to be true.

The fact :that Lai rea tridentata and other long-lived deset perenniaes

develop extensive root systems may also contribute to this idea.

Runyon, (1934) and Vasek,' et al., (1975) showed that Larrea grows out-

ward in concentric rings. The centers die and new shoots sprout from

the periphery. Disturbance by semi-permanent tent cities and other dist-

urbances could possibly sheer off most of the above ground portions of

individual plants. • When disturbance was curtailed many shoots would

sprout from a still viable root system that is perhaps as large as three

meters in diameter. A high apparent density might result which is not

in fact real. This observation may be supported by the positive percent

change in density and a negative percent change in cover in tank track

transects at Camp ibis(Fig, 10) with almost no increase between 1953

and 1974. Thus in this case it appears that •a disturbance may cause an

apparent increase in density and a decrease in cover. Contributing 71

factors such as altered physiognomic characteristics and unoccupied

habitat space might also allow an increase in density but not in total

biomass that the disturbed site could sustain. Thus it appears that

plant response to disturbance is regulated by two main factors with

regards to relationships between the numbers of individuals per unit

area (density) and the percentage of a given area they cover. One is

the extent of substrate disturbance. The second is how near carrying

capacity the community was before disturbance. Due to the harsh nature

of the desert environment many communities are unstable and have widely

varied climax characteristics with much room for fluctuation. Relation-

ships in these two factors influence the relationship between density

and cover in a successional community. Thus far the results of the

aerial photographic analyses are beginning to provide answers to the

objectives stated in the introduction. They have helped determine the

types of disturbance in a broad way in terms of density and cover inter

actions. They indirectly point to the idea of substratc, alteration that

affects the manner in which recovery occurs. This brings up the second •

objective. What are the types of plant response. it has been suggested-.

that response varies with the nearness of a community to the environmept,

al carrying capacity, the types of disturbance, and the intensity of the

. disturbances. Responses have thus far been shown to involve changein

•density and cover. The time required for favorable response is difficult

to discern with just aerial photographic data.

The results of the ground analyses display trends in density an

'cover which support the cbmments made already. The real usefulness for

the ground transect measurements is the information they provide on. 72 species composition which was used to determine values for diversity, stability', and productivity. It has been shown that the results from these analyses of the ground 'atansect data show that diversity was decreased in orderof increasing use intensity. Stability expressed In terms of Community Quality Indices (Table 8) also exhibits this teehd.

In further support of the observation of decreasing community health. with increased disturbance and use intensity, the results of transect. comparison analyses (Table 10, i.Xj) also follow this pattern. The trend was repeated- in terms of productivity, expressed as percent change of

_,:kave - and density from both aerial photographic and ground transect analyses.

Recovery rates, it seems then, are contro ed by the exten,,, of.vegetational denudation and ,the degree of disturbance to the physiognimic environment:. Table .11 (Lathrop, Het al., 1978) shows Patton's maneuver sites in comparison with current recreational vehicle disturbance areas.

Lathrop .(1978) also shows quantitative estimates of percent change for the three use types described(Fig. 14). It is clearlyseen that even with 37 years of recovery, Patton's armored manuevPr area -still-...show a reduction. in perennial vegetation only slightly less than the ,egre.(:,..!. of• discurbance in areas undergoing concentrated current activit-,

In summary, Pattbn's armored manuevers areas will not recover. to, original levels of community health in the foreseeable. future, if atall

All parameters analyzed stll show significant levels of negattv.,:. results with the exception of richness, which shows perhaps a slight increiLS.....,,

This fact, mever, may contribute to community instability. 73

In regards to the objectives stated in the introduction it has been shown in this study that

I. The types of disturbance have been identified as three levels of

use intensity, based on the degree of negative plant response,

they are tent areas, tank tracks, and camp roadways (in order of

increasing use and disturbance intensity).

2. The types of plant response were identified as negative changes

in diversity, stability, and productivity.

3. It is shown that the time required for recovery is greater than

the time elapsed between the disturbance and this study (37 years).

4. It is seen that beyond a certain degree of disturbance, recovery

to pre-disturbance levels is unlikely. Even in less intensively

disturbed areas recovery will require many years to attain pre-

vious levels of community vigor. Table Ii. Comparison of Patton's maneuvers areas CB) with recreational use

study sites in the CDCA.

Use Type Response Type Topography COCA Study Areas

A. Past to recent, Positive to annuals Broadflat, sandy

concentrated to under certain cir- to rocky expanses, •Barstow to Las Vegas

dissipated use. cumstances (edge dunes, washes ab- race course.

Short periods of effect or breaking undant. Kelso Dunes

time for recovery surface of soil for

of vegetation seedlings).

Negative to Long-

lived perennials.

B. Past concentrated Negative denuded roads Fiat, open land.

use inIocalized roads, tracks, and Gravely sand to Camps Ibis and Essex areas. Long per- tent areas. Recovery desert paVement.

iod of time for extremely slow. Not inviting to

recovery ORV's.

C. Concentrated re- Negative forms denuded Steep hills, val- Dove Springs Canyon

cent and current strips (trails and leys, level trails Afton Canyon

activities, no roads) and large ex- Johnson Valley

time for recovery panses of ground (pit areas) Plaster City Fig. l4-:Comparison summaries of mean percent change of perennial vegetation in

relation to increasing disturbance intensity for study areas in the

CNA. Use types are based on descriptions from Table 11. 1 = A; 2

3 = C. 100

1 3

Disturbance Intensity VI. LITERATURE CITED

Brower, J.E., and J.H. Zar. 1977. Field and laboratory methods for general ecology. Wm. C. Brown., Publishers, Dubuque, Iowa. 194, pp.

Hurlbert, S. 1971. The nonconcept of species d-Rersity: a critique and alternative parameters. Ecology 52:577-E86. Johnson, H.B., F.C. Vase, and T. Yonkers. 1975. Productivity, diversity and stability relationships in Mojave Desert roadside vegetation. Bulletin of the Torrey Botanical Club. 102:106-114. Lathrop, E.W., R.J. IvIsiuk, and C.E. Horsley. 1978. Plant response parameters to recreational vehicles in the California Desert Con- servation Area. • Contract It CA-060-RFP7-26, Desert Plan Program, .Bureau of Land Manacjement, Riverside, California. Final report, lobseleaf. 240 pp. McIntosh, R.P. 1967. An ,index of diversity and the relation of certain concepts to diversity. Ecology 48: 392-404. Munz, P.A. 1965. A California flora. University of California Press, Berkeley and Los Angeles. 1861 pp, Runyon, F.H. 1934. The organization of the Creosote bush with respect to drought. Ecology 15:128-138. Thorne, R.F, 1976. The vascular plant communities of California. Symposium proceedings - Plant communitiesof Southern California. edited by June Latting. Special Publication No, 2 California Native. Plant Socie', 164 pp. Vasek, F,C., H.B. Johnson, and D.H. eslinger. 1975. Effects of pipe- • line construction on Creosote bush scrub vegetation of the Mojave Desert. Niadrono 23:1-12. Vasek, F.C. H.R. Johnson, and G.D. Brum. 1975. Effects of power transmis5lot: lines on vegetation of - the Njave Desert. . M,drono 23:114-120. Whittaker, R.H. 1975. Communities and ecosystems. MacMillan Publish- ing Co., Inc., New York. 385 pp.

78 APPENDIX A

Plant Specimen List

Collected in the Eastern Mojave Desert

from September, 1977-June, 1978

Aizoaceae

Mollugo cerviana (L.) Ser. Asteraceae

Acamptopappus sphaerocephalus (Harv. & Gray) Gray Ambrosia dumosa (Gray) Payne

Baileya pauciradiata flarv. & Gray

Bebbia juncea (Bent0 Greene

Brickellia incana Gray

Dyssodia cop_peri Gray

•Dyssodia therberi (Gray) Nels.

tncelia farinosa Gray ex Torr.

Encelia virginensis A. Nels.

.Erigeron ppmilus Nutt. ssp. concinnoides Crong.

Eripphyllum wallacei Gray

•Gutierrez a microrephala (DC.) Gray Geraea canescens T. & G.

Haplooappus acradenius (Greene) Blake

Haplopappus copoeri (Gray) Hail

Mymenoclea salsola T. & G.

Lepidospartum (Gray) Gray

Alchaerara :tortifoli_ (Gray) Crong, & Keck,

-79 80

Palafoxia linearis (Cav.) Lag

Pectis papppsa Harv. & Gray ex Gray

Stephanomeria pauciflora (Torr.) Nutt

Agavaceae

Yucca shidigera Roecie ex Ortigies

Tetradymia stemolepis Greene

Bignoniaceae

Chilopsis linearis (Cav.) Sweet Desert Mallow

Boraginaceae

Coldenia palmeri Gray

Coldenia plicata (Torr.) Coy.

Brassicaceae

4:011flium_fremontii Wats

Cactaceae

Echinocactus polycephalus Engelm & Bigel

Opuntia basilaris Engelm & Bigel

Opuntia echinocarpa Engelm & Bigel

Opuntia ramossima Engelm

Capparaceae

Cleomella obtusifolia Torr. & Frem

Isomeris arborea Nutt. var. arbo,ea (Cleome isomeris Greene)

Chenopodiaceae

Atriplex canescens (Pursh) Nutt

Atriplex humenelytra (Torr.) Wats

Atriplex polycarpa (—Torr, ) Wats

Ceratoides iariatum (Pursh) T. Howe 81

Grayia spinosa (Hook) Mog.

Ephedraceae

Ephedra nevadensis Wats.

Euphorbiaceae

Croton cali ornicus Muell-Arg

Fabaceae

Acaccia 2yegai tray

Cassia armata Wats.

Cercidium floridum (Benth) Wats. Benth

Dalea californica Wats.

Dalea emoryi Gray

Prosopis glandulosa Torr. var. torreyana . Benson) M.C. Jtn.

Lamiaceae

Salvia columbariae Benth.

Salvia dorii (Kell.) Abrams

Salazaria mexicana Torr.

Lennoaceae

Pholisma arenarium Nutt. ex Hook.

Loasaceae

Petalonyx thurberi G.

Malvaceae

Eremalche rotundifolia Gray Greene

Nyctaginaceae

Mirabilis froebelsi (Behr.). Greene

Papa veraceae

Argemone cs_gmbosa Greene 82

Plantaginaceae

Plantago aristata Michx.

Poaceae

Airstida fendle0. aa Steude•

Routeloua bary0;,..a. Lag:

13outeloua eripp0.a. (Torr.) Torr. - Eripneurop piioum (Buckl) Nash

Hilaria jamesii (Thurb.) Benth. ex Scribn.

Hilaria rigida 1(Thurb.) Benth. ex Scribn.

Muhienbergia potteri Scribn.

Oryzgpsis humenoides (R.& S.) Ricker

Tridens muticus (Torr.) Nash

Po ygonaceae

Eriogonum fasciculatum Benth

Erio9onum heerimannii Dur. & Hilg.

Eriogonum inflatum Torr. & F

Roasaceae

Coleoune ramosi,ssima Torr.

Failugia paradaxa (D. Dom) Endl

Prunus fasciculata (Torr.) Gray

Solana6eae

Datura meteloides A. DC.

Lyçium cooperi Gray

Zygophyl I a ceae

Larrea tri, tita_ (Sesse & Mbc PX DC.) Coy. APPENDIX B

Symbols and Calculations

1. Symbols

k = total number of points

u = unit area

= species

ni = number of individuals of a species

• RD. = relative density

D. = density of individual species

ji = number of sampling points at which species i was counted

• f. = frequency of species

Rf. = relative frequency

• a. = area covered from all quandrants

• C. = coverage for all species

TD = total density

di = point to plant distance

d = sum of d.

A mean= area per plant

2. Calculations

RD = n./ i Di = (RD)(TD)

fi = ji/k

Ci = (ai)(Di)

RC = Ci/23C.

= d2

TD = u/A 83 APPENDIX C

Aerial Photograph Calibrati on Data

CAMP IBIS

photograph date 68,9-i974

photograph nos. BLI-C-M000 9-10-12; 14-10-12; 15 9-12

BLM-C-M000 17-9,10,11; 18-7,8; 16-11,12,13,14

photograph size 9" x 9"

Ratio 1:20,000

Transparent Grids On Ground Equivalents

Each side of the small squares Each side of th,, small squares

= .10 cm. = 20.0 in.

Entire grid is 2.95 cm. x 1.9 cm. Entire grid is 590.0 m. x 380.0

Area of small squares = .04 ha

Area of entire grid = 22.42 ha

photograph date 4-23-1953

photograph nos. GY-YP 2-15,17,18,19,20,21; 3234,35,36.37 ,38,39

photograph size 18" x 18"

Ratio 1:34,800

Tr4nsp-rnG. _ . Eouivalents.

Each side of the small squares Each side of the sma ll squares

= .10 cm. 34.8 m.

Entire grid is 2.95 cm. x 1.9 cm. Entire grid is 1026.6 m. x 661.2 in.

Area of small squares - .12 ha

Area of entire grid = 67.8 h-

[TV L[E3RAR

CAUFON1• • 1

APPENDIX C

Aerial 'Photograph Calibration Data

CAMP ESSEX

photograph date 6-8-1974

photograph nos. BLM-C-M000 8-4-8

photograph size 9" x 9"

Ratio 1:20,000

Transparent Grids - On Ground Equivalents

Each side of the small squares Each side of the small squares = .10 cm. = 20 m.

Entire grid is 2.95 cm. x 1.9 cm. Entire grid is 590.0 m. x 380.0 m.

Area of small squares = .04 ha

Area of entire grid = 22.42 ha

photograph date 4-23-1953

photograph nos. GS-YP 2-174,175,176

photograph size 18" x 18"

Ratio 1. ,54 ,800

raquarent Grids On Ground Equivalents

Each side of the small squares Each side of the small squares = •.10 _m. =. 34.8 m.

Entire grid is 2.95_cm. x 1.9 cm. .Entire grid is 1026.6 m x 661.2 m.

Area of small squares = .12 ha

Area of entire grid . '7,8 ha