EFFECTS OF GRAZING AND TRAMPLING BY ROCKY MOUNTAIN ELK (Cervus elaphus nelsoni) ON THE VEGETATIVE...

EFFECTS OF GRAZING AND TRAMPLING BY ROCKY

MOUNTAIN ELK (Cervus elaphus nelsoni) ON

THE VEGETATIVE COMMUNITY OF BANDELIER

NATIONAL MONUMENT, NEW MEXICO

by

SUSAN P. RUPP, B.S.

A THESIS

IN

WILDLIFE SCIENCE

Submitted to the Graduate Faculty of Texas Tech University in

Partial Fulfillment of the Requirements for

the Degree of

MASTER OF SCIENCE

Approved

December, 2000

8'^S ACKNOWLEDGMENTS /^A/I^ ~9Z^^

c-;, I would like to extend my utmost gratitude to the National Park Service,

t^i J ,1^ specifically Bandelier National Monument, and Texas Tech University for providing

funding and the opportunity to conduct this research. I would also like to thank my co-

advisors. Dr. Mark Wallace and Dr. Rob Mitchell, for their vast knowledge, support and

valuable insight. You have instilled in me direction, purpose, and dedication through

your example and generosity. My other committee members, Dr. David Wester and Dr.

Andy Herring, have also provided considerable guidance. Specifically, Dr. Wester has

opened his office door more times than I deserve. His statistical assistance, insight, and

support have tmly enlightened me.

I would also like to thank the personnel of Bandelier National Monument. They

have served as wonderful mentors and friends at my "home away from home." Mr.

Stephen Fettig and Dr. Craig Allen have provided knowledge of the Pajarito Plateau

which has greatly enlightened my perceptions of the difficulties endured by managers in

this area. I am also greatly indebted to Mr. Brian Jacobs, vegetation specialist at

Bandelier, who identified and confirmed numerous unknown plant specimens that were

collected in the field. Finally, Ida Formea, Kay Beeley, John Hogan, and Vicki Estes

illuminated my days with good conversations, and many laughs.

Without the assistance of my various field technicians, data collection would have

been impossible. Erika Hersch, Cindy Caplen, Doug Krantz, Christine Evans and Salinda

Daley endured many hours of long, tedious data collection and I thank them for their hard

work and patience throughout this project. With their help, I have learned more about

ii

managing and supervising field technicians than I ever thought I could learn in such a

short amount of time. Their friendship also helped me to endure the monotonous hours in

the field.

My deepest heartfelt gratitude goes out to my husband, Paul Rupp, whose love

and companionship has provided strength when I felt little left to give. His vast computer

knowledge has saved me (and my data!) in moments of potential catastrophe and I cannot

thank him enough for creating the database on which I stored my data. The faith, love,

and support he has shown me have been my inspiration, as a professional and as a human

being, and words cannot express how richly blessed I am to be loved by such a wonderful

person.

Finally, I would like to thank Our Heavenly Father for providing this incredible

opportunity to complete my graduate education and for answering our prayers under what

appeared to be insurmountable circumstances. It is to Him I dedicate this work.

ni

TABLE OF CONTENTS

ACKNOWLEDGEMENTS ii

ABSTRACT vi

LIST OF TABLES viii

LIST OF FIGURES x

CHAPTER

I. INTRODUCTION AND LITERATURE REVIEW 1

IL BACKGROUND INFORMATION 7

Study Area 7

Justification 10

Objectives 14

III. MATERIALS AND METHODS 21

Experimental Design 21

Parameters Measured 23

IV. RESULTS 30

Intensity Study 30

Frequency Study 35

Reference Area Analysis 39

V. DISCUSSION AND MANAGEMENT IMPLICATIONS 63

LITERATURE CITED 71

IV

APPENDIX A: EXCLOSURE MAPS 78

APPENDIX B: SUMMARY STATISTICS FOR PLOT A 92

APPENDIX C: SUMMARY STATISTICS FOR PLOT B 97

ABSTRACT

The increase in the Jemez region elk (Cervus elaphus nelsoni) population is a

concem to local managers. Threats to archeological resources and naturally fijnctioning

ecosystems through accelerated soil erosion, degrading plant communities, and unnatural

vegetation change rank as the highest management priorities at Bandelier National

Monument, New Mexico.

In summer 1998, Bandelier National Monument erected a series of ungulate

exclosures and paired reference areas to evaluate elk impacts on the vegetative

community in piilon-juniper (PJ), ponderosa grassland (PG), and mixed-conifer (MC)

habitat types. A two-factor factorial randomized block design was established to evaluate

simulated grazing/trampling treatment combinations applied at different intensities and

frequencies from January through May of 1999 and 2000. Unfenced reference areas were

compared with non-treated units inside exclosures to evaluate the effects of grazer

exclusion. Parameters measured included density, percent foliar/litter cover, mean basal

area/plant, productivity, and species richness and composition.

Analysis of covariance (ANCOVA) was used to account for pre-treatment

patterns that existed among treatment plots. Pre-treatment and first-year response data

indicated large amounts of variation between and within exclosures for all parameters

measured which may reflect the inherent variability present in vegetative communities at

Bandelier National Monument. Few significant responses were detected following a

VI

single year's treatment application and two unseasonably warm winter/spring periods

may have confounded or obscured treatment effects.

Responses differed between habitats and among treatments applied. In PJ habitat,

heavily clipped plots had more plants and less litter, but lightly trampled units had more

foliar cover, specifically forb cover, than moderately trampled units. In PG habitat, non-

trampled units had lower plant density, specifically forb density, but lightly trampled

units had more litter cover than heavily or non-trampled areas. Plots clipped at the

highest frequency also had more grass plants, but less litter when coupled with moderate

trampling. In MC habitat, moderate intensities of clipping and trampling resulted in

higher grass cover. Non-clipped units had higher litter cover. Light or moderate

intensities of trampling or a combination of moderate clipping/trampling frequencies

increased species richness. Frequent, heavy clipping also resulted in lower total

productivity in MC sites. Significant year effects were detected for basal measurements

in most cases, but these could not be attributed to treatments. Shifts in species

composition were dependent on habitat, but showed potential trends in response to

clipping or trampling. No significant effects were detected due to grazer exclusion.

Trampling more consistently impacted parameters and may stimulate plant

productivity at an intermediate intensity, especially in terms of forb response. Seasonal

progression and phenological development of individual plants may confound effects of

defoliation frequency and intensity. Longer time periods may be needed to detect

vegetative responses to changes in grazing pressure especially in ecosystems that have

developed with a history of grazing pressure.

vn

LIST OF TABLES

4.1 Adjusted mean density by habitat for different intensities of clipping and trampling treatment combinations in 2000 43

4.2 Adjusted mean foliar cover by vegetative type for different intensities of clipping and trampling treatment combinations in PJ habitat 44

4.3 Mean litter cover by habitat for different intensities of clipping and trampling treatment combinations in 2000 46

4.4 Relative composition of common species in 1999 vs. 2000 by habitat for different intensities of clipping and trampling treatment combinations 47

4.5 Adjusted mean density by vegetative type for different intensities of clipping and trampling treatment combinations in PG habitat 48

4.6 Mean litter cover by habitat for different frequencies of clipping and trampling treatment combinations in 2000 51

4.7 Adjusted mean density by vegetative type for different frequencies of clipping and trampling treatment combinations in PJ habitat 52

4.8 Average initial productivity following first clipping treatment and subsequent regrowth for second and third clipping treatment 53

4.9 Relative composition of common species in 1999 vs. 2000 by habitat for different frequencies of clipping and trampling treatment combinations 54

4.10 Adjusted mean density by vegetative type for different frequencies of clipping and trampling treatment combinations in PG habitat 55

4.11 Adjusted arcsine transformed means for foliar cover by vegetative type for different frequencies of clipping and trampling treatment combinations in MC habitat 57

4.12 Mean densities inside versus outside exclosures 60

4.13 Mean foliar cover inside versus outside exclosures 61

4.14 Mean litter cover inside versus outside exclosures 62

B.l True means for total density by habitat and treatment 93

vni

B.2 Tme means for foliar cover by habitat and treatment 94

B.3. Tme means for total litter cover by habitat and treatment 95

B.4. Tme means for total richness by habitat and treatment 96

CI Tme means for total density by habitat and treatment 98

C.2 Tme means for foliar cover by habitat and treatment 99

C.3 Tme means for total litter cover by habitat and treatment 100

C.4 Tme means for total richness by habitat and treatment 101

IX

LIST OF FIGURES

2.1 Bandelier National Monument, New Mexico 16

2.2 Region bumed by the 1977 La Mesa Fire in and near Bandelier National Monument, NM 17

2.3 Region bumed by the 1996 Dome Fire in and near Bandelier National Monument, NM 18

2.4 Monthly temperature for the 1998-1999 and 1999-2000 field seasons compared to the monthly average in Los Alamos, New Mexico 19

2.5 Monthly precipitation for the 1998-1999 and 1999-2000 field seasons compared to the average temperature at Los Alamos, New Mexico 20

3.1 Exclosure locations at Bandeher National Monument, New Mexico 27

3.2 Exclosure layout 28

3.3 Designation of clipping X trampling treatment combinations inside exclosures. 29

4.1 Adjusted mean foliar cover by habitat in response to trampling intensity 42

4.2 Mean litter cover by habitat in response to clipping intensity 45

4.3 Mean foliar cover for grasses for different intensities of clipping X trampling treatment combinations in mixed conifer exclosures 49

4.4 Mean litter cover by habitat in response to clipping frequency 50

4.5 Mean litter cover for different frequencies of clipping X trampling treatment combinations in PG exclosures 56

4.6 Species richness in response to different frequencies of clipping X trampling treatment combinations in MC exclosures 58

4.7 Mean primary productivity in response to clipping frequency in MC habitat 59

A.l Experimental layout for exclosure/reference area 'PJ-l ' 79

A.2 Experimental layout for exclosure/reference area 'PJ-2' 80

A.3 Experimental layout for exclosure/reference area 'PJ-3' 81

X

A.4 Experimenta

A.5 Experimenta

A. 6 Experimenta

A. 7 Experimenta

A. 8 Experimenta

A.9 Experimenta

A. 10 Experimenta

A. 11 Experimenta

A. 12 Experimenta

A. 13 Experimenta

layout for exclosure/reference area 'PJ-4' 82

layout for exclosure/reference area 'PJ-5' 83

layout for exclosure/reference area 'PG-2' 84



layout for exclosure/reference area 'MC-l' 87

layout for exclosure/reference area 'MC-2' 88




XI

CHAPTER I

INTRODUCTION AND LITERATURE REVIEW

Grazing has the potential for altering botanical composition, cover, and soil

physical properties through herbivory and associated trampling (Warren et al. 1986).

Kind of animal, season and intensity of use, soil characteristics, individual plant and

community characteristics (e.g., density, morphology, physiology), and temporal and

spatial variation in environmental conditions influence the type and degree of impact

(Weigel et al.l990, Bastrenta et al. 1995). Direct impacts of grazing may include plant

defoliation, nutrient removal and redistribution through excreta, and mechanical

manipulation of the soil and plant material through associated trampling. Indirect

impacts can include changes in infiltration rates, soil erosion and sediment production,

and plant productivity.

A substantial body of information exists conceming the effects of grazing by

domestic ungulates (Olson and Richards 1988, Ralphs et al. 1990, Biondini et al. 1998),

but the majority of these studies were conducted by manipulating grazing systems.

Grazing systems are partially defined by the intensity (amount of plant material removed)

and frequency (the number of times a plant is defoliated) of use which, in tum, affects

both the quality and quantity of forage produced (Motazedian and Sharrow 1990). Few

studies have attempted to isolate the effects of intensity or frequency of use (Gillen et al.

1990) and it is often unclear whether impacts are caused by the removal of vegetation or

associated trampling. Studies that have isolated impacts of grazing (Oesterheld 1992) or

trampling intensity (Warren et al. 1986, Abdel-Magid et al. 1987, ToUner et al. 1990)

have ignored possible interactive effects.

It may not be possible to control the intensity of defoliation on individual plants

in conventional grazing systems since management controls only the frequency of

grazing events through periodic rest/rotation grazing regimes to maintain desired

species composition (Ralphs et al. 1990). Demer et al. (1994) confirmed that rotational

grazing allows greater control of defoliation frequency, but not defoliation intensity.

They found similar heights of grazed plants within continuous and rotational grazing

systems and determined that grazed height was influenced primarily by stocking rate.

Frequency and composition of forages may decline as stocking rates increase (Ralphs et

al. 1990). Controlling grazing regimes and stocking rates is often not possible where

wild ungulates are the primary source of impacts and other management altematives

must be evaluated.

Vegetative impacts caused by Rocky Mountain elk (Cervus elaphus nelsoni)

grazing and trampling have been a growing concem for natural resource managers

(Gmell 1973, Houston 1982, Despain 1989, Kay 1997), but few studies have described

impacts caused by excessive elk grazing. McCulloch (1955) described over-browsing

by elk in the Selway-Bitterroot Wildemess Area, Idaho. He found that with a decrease

in browse species, there was an increase in less desirable species such as cheatgrass

(Bromus tectorum) and goatweed (Hypericum perforatum). Conifers in winter range

developed a browse line (bark entirely browsed to the height ungulates could reach) and

seedling emergence was poor (McCulloch 1955). Similarly, Hoskins and Dalke (1955)

found high erosion and an increase in less desirable plant species on the Pocatello Big

Game Range in Southeastem Idaho due to a combination of livestock and elk grazing.

Gaffney (1941) reported similar effects of winter elk browsing on the Flathead

River, Montana, but found the greatest damage to grass occurred through early grazing

and trampling in the spring. Conifers developed a well-defined browse line in highly

populated areas. However, winter ovemse was not related to erosion in Montana.

Other studies have reported that intensive grazing results in an increase of less palatable

plant species and inhibited growth of willows (Salix spp.), shmbs, and aspen (Populus

tremuloides) shoots (Hoskins and Dalke 1955, McCulloch 1955, Kay 1994, Kay 1995,

Kay 1997).

Croft and Ellison (1960) and Gmell (1973) evaluated elk impacts on the Big

Game Ridge, Wyoming. Croft and Ellison (1960) concluded soil erosion, vegetative

destmction, aspen barking, and increased mnoff were the result of excessive use by elk.

In contrast, Gmell (1973) did not find evidence to support these conclusions. Croft and

Ellison (1960) recommended further studies of elk grazing and relative amounts of

trampling.

The trampling of ranges associated with intensive grazing may be of value for two

reasons (Balph and Malecheck 1985). First, the action of the hooves of an animal in

breaking the soil surface and in mixing and breaking up litter may aid plants in obtaining

water and nutrients. Second, trampling of caespitose grasses may break down the

standing dead material within ungrazed plants, which is known to inhibit grazing.

Modifications of soil stmcture and/or microtopography by animal trampling can also

influence the number of microsites available for seed germination (Savory and Parsons

1980, Weigel et al. 1990, Winkel and Roundy 1991). Trampling, in conjunction with

plant competition, soil characteristics, and moisture regime, may affect plant species

differently enhancing some while reducing the abundance of others (Weigel et al. 1990).

Livestock trampling also affects infiltration rates and bulk density of soils

(Tollner et al. 1990). However, productivity (e.g., root biomass, forage growth) may

not be significantly reduced. Warren et al. (1986) found that infiltration rates were

consistently higher and sediment production lower before trampling than after

regardless of soil moisture at the time of trampling. Impacts on infiltration increased

with increased stocking rates (Warren et al. 1986). In many semi-arid and arid regions

where vegetation is sparse, recovery from trampling effects may be slow.

Sun and Liddle (1991) emphasized the importance of plant resistance (ability to

withstand impact), survival (the probability of surviving following impact), and recovery

(the growth rate following damage) in regulating ecosystem stability. Similar concepts

were discussed by Cole (1988, 1995a,b) in which he measured plant "deterioration" and

"species persistence" following human trampling of ecosystems. Relative cover varied

significantly with both trampling intensity and vegetation type. In general, community

response varies with habitat type and species (Olson et al. 1985, Campa et al. 1992, Cole

1995a,b).

Identifying causative factors for vegetative change is a complex problem.

Fluctuations in vegetative communities may relate more to short-term climatic

conditions rather than to the effects of ungulates. Houston (1982) evaluated impacts of

the northern Yellowstone elk herd prior to the 1988 Yellowstone fire and determined

that evidence does not support interpretations from early reports of widespread or

accelerated erosion in the area. Data reflect fluctuations in plant communities in

response to short-term climatic conditions rather than long-term directional changes

caused by elk (Houston 1982). He showed that persistent heavy winter and variable

spring grazing, with associated trampling, did not cause extensive plant mortality or

progressive changes in density or basal area on his study area in Yellowstone National

Park. Periods of major elk reductions did not result in areas with different species

abundance, basal area, or composition compared to heavily grazed areas.

Though not much can be found in the literature about vegetative responses to

grazing pressure in conjunction with climatic factors, environmental variation can play

an important role. Winkel and Roundy (1991) found seedling emergence in response to

cattle trampling differed among years and treatments relative to precipitation pattems

and periods of available water. Olson et al. (1985) indicated each species reacts to

precipitation regimes and grazing pressure in a unique manner. They concluded that

changes in stocking rates need to be anticipated and planned to coincide with available

forage because of large fluctuations in cover due to varying precipitation. It is

important to determine the effects of grazing and environmental variation on the rates

of plant growth and to determine how these may interact to regulate the dynamics of

plant communities (Bastrenta et al. 1995).

Exclosures are a standard method used to observe changes in vegetative

communities when grazing animals are excluded from an area. In southwestem North

Dakota, Brand and Goetz (1986) found major differences in species composition between

exclosed and adjacent domestically grazed plots over the course of 3 years. However,

total yield and total below ground biomass were not significantly different in 3 of their 4

5

plots. Tollner et al. (1990) used exclosures in their study on trampling effects of

domestic stock on soil properties in Georgia. They found trampling altered surface soil

stmcture, but productivity (root biomass, forage growth) was not significantly reduced.

In Colorado, Tucker and Leininger (1990) reported that total vascular vegetation, shmb,

and graminoid canopy cover was greater in riparian exclosures than in grazed areas

whereas forb canopy cover was similar between treatments. In addition, exclosures had

nearly 2 times more litter cover whereas grazed areas had 4 times more bare ground.

Exclosures have been used to determine grazing impacts by elk (Gmell 1973, Despain

1989) but results are inconsistent and ftirther studies are needed.

Grazing and trampling can have a wide range of effects from direct changes in

botanical composition and stmcture to changes in soil physical properties. The impacts

of domestic grazing and trampling are well-documented, but the need for wild ungulate

research on national parks has been iterated (Leopold 1963). Studies have used

exclosures to document impacts by elk, but results are inconsistent. In addition, long

time periods - periods in the range of 20 years - may be needed to detect vegetative

responses to changes in grazing pressure (Chong 1992) especially in ecosystems that

have developed with a history of grazing pressure. Further studies isolating the effects of

elk grazing and trampling are needed.

CHAPTER II

BACKGROUND INFORMATION

Study area

Bandelier National Monument (BAND) is located in the Jemez Mountains of

north central New Mexico (35:53:38N 106:17:02W) approximately 8 km south of Los

Alamos in an area called the Pajarito Plateau (Figure 2.1). The monument was

established as a National Park in 1916 by Presidential Proclamation (Lissoway 1996).

Although the area is rich in natural resources, the park was originally established to

preserve and protect the relicts of the Anasazi people who occupied the canyons and

mesas of the plateau from the 1 lOO's through the 1500's. It is estimated that there are

over 3,000 active archeological sites within the region (Foxx 1984). The threat to

archeological resources and naturally functioning ecosystems through accelerated soil

erosion, degrading plant communities, and unnatural vegetation change now rank as the

highest priorities in Bandelier's Resource Management Plan (Fettig 1997).

The Pajarito Plateau was formed by an ash flow of volcanic activity about 1.4

million years ago (Wilcox and Breshears 1994) resulting from the formation of a giant

caldera, the "Valle Grande", 30.4 km west of the Bandelier entrance station. Soils of the

area are derived from ryholite, tuff, ash, and other volcanic debris and can be classified

into three groups: (1) extremely rocky, shallow soils less than 51 cm deep on steep

canyon slopes, (2) moderately deep (51-91.5 cm) soils on mesa tops, and (3) sandy

alluvial soils on the canyon bottoms (Foxx 1984). Bandelier is bordered by Santa Fe

National Forest to the west, Los Alamos National Environmental Research Park

7

(LA/NERP) to the east, and private lands to the north and south. Native American

reservation lands are also found throughout the surrounding areas.

The monument's 13,290 hectares range in elevation from 1,680 m in the lower

canyons near the Rio Grande to about 3,240 m near the summit of Cerro Grande. The

area is transected by 3 main canyons - Frijoles, Capulin, and Alamo - and a system of

smaller canyons making the terrain rough and virtually inaccessible in some places.

Vegetative pattems are highly dependent on elevation and topography (Wilcox and

Breshears 1994).

Three distinct vegetation associations can be described (Conley et al. 1979).

Lower elevations (1,680-2,015 m) are characterized as piilon-juniper woodland. Species

composition in these areas includes moderate stands of pifion pine (Pinus edulis) and

one-seed juniper (Juniperus monosperma) with understory shmbs of wavy leaf oak

(Quercus undulata), Apache plume (Fallugia paradoxa), and mountain mahogany

(Cercocarpus montanus). Mid-elevational transitional areas (2,015-2,440 m) are

characterized by an overstory of ponderosa pine (Pinus ponderosa) and understory of

Gambel oak (Quercus gambelii), New Mexican locust (Robinia neomexicana), and

mountain mahogany. Typical grasses in the transitional zone include mutton grass (Poa

fendleriana), June grass (Koeleria cristata), and mountain muhly (Muhlenbergia

montana). Upper elevations (2,440-3,240 m) are classified as mixed-conifer with a

variety of overstory species that include Douglas fir (Pseudotsuga menziesii), white fir

(Abies concolor), blue spmce (Picea pungens), and quaking aspen. Gambel oak, rock

spirea (Holodiscus dumosus), and waxflower (Jamesia americana) are typical understory

shmbs and slender wheatgrass (Agropyron trachycaulum), Canada bluegrass (Poa

8

compressa), and Parry oatgrass (Danthonia parryi) are common grasses in the mixed-

conifer zone. Canyon bottoms have riparian communities that include narrowleaf

Cottonwood (Populus angustifolia) and boxelder (Acer negundo).

In 1977, approximately 6,180 ha of land in Santa Fe National Forest, BAND, and

LA/NERP bumed in the "La Mesa" fire (Figure 2.2). Sixty-nine percent, or 4,250 ha, of

the total area bumed was on BAND alone (Foxx 1984). The La Mesa fire converted

dense, monotypic ponderosa pine forests into a more productive and diverse mosaic of

grassland, shmbland, and forests. Severely bumed areas were denuded of herbaceous

cover but were revegetated with aerial seeding of native grasses (Conley et al. 1979).

The 1977 La Mesa fire is believed to have contributed to a population increase of the elk

herd (Allen 1996). Other more recent fires, such as the "Dome" fire in April 1996

(Figure 2.3) and a number of prescribed bums set by management at BAND have also

contributed to the ecology of this region, although direct effects on the elk population

have not been documented.

Average annual precipitation on the Pajarito Plateau is 330 to 460 mm (Davenport

et al. 1996, Wilcox et al. 1996) of which about 45% occurs in July, August, and

September. Average daytime temperatures range from 32.2°C in the summer (max. =

41.1°C) to -9.4°C in the winter (min. = -30.6°C). Over the two years of data collection

for this study, temperatures were generally higher than the 1920-1999 average with the

exception of April 1999 when an unseasonal cold front came through (Figure 2.4).

Annual precipitation during the 1998-1999 and 1999-2000 field seasons were also lower

than average (Figure 2.5).

Justification

Management of wildlife on National Park Service (NPS) land is a controversial

topic (Buono 1997). With the establishment of the first national park, Yellowstone, in

1872, Congress forbade the wanton destmction and market hunting offish and game in

the area. Forty-four years later, the Organic Act of 1916 charged the NPS with a mission

".. .to promote and regulate the use of all Federal areas known as national parks,

monuments, and reservations.. .which purpose is to conserve the scenery and the natural

and historic objects and the wild life therein and to provide for the enjoyment of the same

in such manner and by such means as will leave then unimpaired for the enjoyment of

future generations" (Buono 1997, p. 23). Despite such regulations, there have been

considerable disputes over federal versus state ownership of wildlife (e.g., Geer vs.

Connecticut 1896, Hunt vs. United States 1928, United States vs. Moore 1986; Buono

1997).

New Mexico and Bandelier National Monument are not strangers to the legal

constraints surrounding the management of wildlife on federal lands. In 1968 (New

Mexico vs. Udall), New Mexico challenged the NPS in regard to obtaining permits from

the state to sacrifice deer (Odocoileus hemionus) in Carlsbad National Caverns Park for

research purposes (Buono 1997). New Mexico stated that destmction of the animals did

not serve to protect federal property. After winning their case in District Court, New

Mexico was defeated before the U.S. Tenth Circuit Court of Appeals which stated that

the research was necessary to ascertain the number of deer the area would support based

on dietary analysis (Buono 1997). A second major battle arose after Congress enacted

the Wild Free-Roaming Horses and Burros Act (1971). Again, the state challenged the

10

regulatory authority of the federal government over management of wildlife on

unreserved public lands (Kleppe vs. New Mexico 1976; Buono 1997). The court system

eventually over-mled New Mexico stating "the complete power that Congress has over

public lands necessarily includes the power to regulate and protect the wildlife living

there" (Buono 1997, p. 21) and citing jurisdiction under the Property Clause of the U.S.

Constitution. In the early 1980's, BAND was sued to prevent the removal of wild burros

from monument property, but the judicial system mled in favor of BAND and allowed

removal of the non-native burro population. Today the scene is set for a major political

and litigious battle conceming elk management in northem New Mexico that hauntingly

parallels some of these earlier battles.

Rocky Mountain elk are considered native to the Jemez Mountain region of north

central New Mexico, but it is thought they were extirpated from the area by 1906 (Allen

1996). In 1948, the New Mexico Department of Game and Fish (NMGF) released 21

cows/calves and seven bulls imported from Yellowstone National Park into the Jemez

Mountain region (Allen 1996). By 1961, the estimated population was 200 animals, all

descendents of the original 28 founders (Allen 1996). Since then, it is believed that the

population has exhibited an exponential increase, partially in response to the 1977 La

Mesa fire when thousands of hectares of wintering range was created (Wolters 1996).

Current estimates of the population in and around Bandelier National Monument are

6,000 to 8,000 individuals with an annual growth rate of 13% and a doubling time of 5.7

years (Fettig 1997). Allen (1996) estimated an annual growth rate of 21.3% and doubling

time of 3.6 years between 1978 and 1992 on Bandelier alone. Other studies have also

reported annual growth rates of elk exceeding 20% (McCorquodale et al. 1988).

11

Some impacts of elk on the vegetation and soils of BAND are apparent (Fettig

1997). Intensive browsing may be largely eliminating aspen suckers from upland

portions of the La Mesa fire and the headwaters of the Frijoles watershed (Allen 1996).

Mature aspen trees are heavily barked in many areas. Heavy browsing is apparent on a

variety of shmbs including New Mexico locust, oaks (Quercus spp.), and small

buckbmsh {Ceanothus fendleri) throughout the elk wintering range on BAND. Meadows

appear to be kept in the early stages of succession by excessive elk use (Wolters 1996).

Severe erosion, potentially the result of a combination of historical cattle {Bos

spp.)(through the early 1900's) and elk grazing, exists in Bandelier's piii on-juniper

woodlands (Wilcox et al. 1996). Erosion is estimated at an unsustainable rate of 0.53

cm/year (Fettig 1997). About 70% of Bandelier's cultural resources are being damaged

by erosion (Allen 1996) and there is concem that elk impacts to the area may accelerate

erosion due to excessive trampling and loss of herbaceous cover resulting from grazing

(Fettig 1997). Similar impacts of domestic livestock grazing are found throughout the

scientific literature (Warren et al. 1986, Tollner et al. 1990), but information on the

impacts of wild ungulate grazing is limited.

The New Mexico Department of Game and Fish is developing an elk management

plan for the state. However, National Park Service and NMGF interests often conflict

with each other and neither agency has a confident estimate of the actual population size

is in or around BAND. Though NMGF is aware that the elk populations are expanding,

their main objective is to provide recreational opportunities for area sportsmen and other

interested individuals (NMGF 1997). They are concemed that expanding populations

throughout the state are responsible, in part, for increased depredation complaints from

12

private landowners and land resource agencies (NMGF 1997). Furthermore, constituents

are concemed that increasing elk numbers are directly related to declining deer

populations, although this has not been documented. NMGF (1997, p. 4) states, "Elk

populations, in some areas, may have exceeded social/political carrying capacities."

The increasing elk populations have resulted in other impacts to the Jemez

Mountain region. Local residents of Los Alamos and White Rock report an increased

number of elk/vehicle accidents on roads along the monument boundaries (Parker 1997).

To complicate matters, nearby San Ildefonso Pueblo has issued a proposal that would

allow them to hunt in BAND using archaic methods and equipment for traditional and

ceremonial purposes (Fettig 1997). Divergent management objectives of the state of

New Mexico, LA/NERP, BAND, tribal communities, and the large, once privately owned

"Baca Ranch" hampers effective elk management (Allen 1996).

Hunting on BAND is expressly prohibited by Code of Federal Regulations (CFR),

Title 36, Part 2, Sections 2.1-2.4 (Fettig 1997); any direct reduction of the elk herd would

require a legislative act of Congress. Before any actions can be taken, however, there is a

need for quantitative, scientific information on the potential impacts of the Bandelier elk

herd. Population dynamics must be evaluated and impacts to vegetative and soil

communities, if any, must be quantified.

The need for ungulate research on national parks has been iterated. In 1963, an

Advisory Board was requested by the Secretary of the Interior to consider the procedure

of removing excess ungulates from national parks (Leopold et al. 1963). The Board

evaluated management methods and concluded that active management within national

13

parks should be aimed at restoration of natural communities. The application of proper

research methodology to address management concems is a necessity.

Objectives

There is no question that elk numbers are increasing in and around BAND.

Instead, the question becomes how to manage the elk herd. The National Park Service

and the state of New Mexico need quantitative research to document elk impacts on

vegetation so informed management decisions can be made. Though inferences can be

drawn from the existing literature on the effects of domestic grazing, many questions still

need to be answered on a site-specific basis for wild ungulates.

Our objectives were to:

• assess changes in density, percent foliar/litter cover, basal area, species

richness, and composition through the application of different intensities

and/or frequencies of clipping and trampling within elk exclosures;

• develop models that relate plant community response to intensity and

frequency of use in three habitat types (i.e., piilon-juniper, ponderosa pine,

mixed-conifer) at Bandelier National Monument;

• determine the effects of ungulate exclusion on the vegetative parameters

mentioned above through the use of exclosures.

Chong (1992) indicated that long time periods - longer than the scope of this study - are

needed to detect vegetative responses to changes in grazing pressure. Change due to

grazing is especially difficult to detect in ecosystems that have developed with a history

of grazing pressure. The greatest changes may come from the release of grazing pressure

14

inside ungulate exclosures. The null hypothesis states that there will be no change in

density, percent foliar/litter cover, basal area, species richness, or composition in

response to clipping/trampling treatments. I predict that measured vegetative parameters

will only respond to extreme levels of clipping and trampling because moderate levels

will mimic what is actually occurring in the system and changes in vegetative stmcture

will not be evident during the scope of this study. In addition, changes in species

composition and richness will be most evident in non-clipped plots inside exclosures

when compared to reference plots outside exclosures due to the release from grazing

pressure.

15

." 'yi '1-

l#rA*,--;--- - .,Sa^* . ' ' t ^ -^ , e

•,*-J

T3 •4—t

a

TD C CO c/a U cd

• « - ^ o u aC

o ON

W3

a, a 8:2 o PH

g a. SaS

c u o ;=; a o

.2^ fe '<3 S -o '

CQ g

^ I • > < <

Id

O ^

<u <u

fc .£

16

\^

^ ^ Forest Roads 289 and 142 / \ / Highways I \ Bandelier National Monument A V Major Creeks and Streams 1 ^ La Mesa Fire Region

Bandelier Wildemess 5 if' Dome Wildemess

0

0

4 Kilometers

4 Miles

Fig. 2.2. Region bumed by the 1977 La Mesa Fire in and near Bandelier National Monument, NM.

17

/ ^ F o r e s t Roads 289 and 142 A/Highways I I Bandelier National Monument / \ / Major Creeks and Streams 1 ^ I^nic Fire Region

•:;: Bandelier Wildemess 'M' Dome Wildemess

0

0

4 Kilometers

4 Miles

Fig. 2.3. Region bumed by the 1996 Dome Fire in and near Bandelier National Monument, NM.

18

<L>

D. E

[ont

hly

Te

2

03

> < 1

1

1

i n

ON O

98-1

9

99-2

0

o o

u u

empe

ratu

r

empe

ratu

r

H H

c c o o 1

1 •

tr

 v ^ vi> X ^ ^

X ^ 1 X ^ ^

1 X

\ \

v\ \

u _ 1

\

\

I\[

V

PV

J

^ 1

>M / >

-y *r * ^^ t ^ ^

^Vx

t^^

M

o

s

V

f

f

1 1

o m o 1-H

xa •#rf

s o

I 1

ir> o 1 1 - H

2 o S

o TD

com

pa

( / }

o C/5

CO

fiel

d

o o o CN

1

OS OS OS T - H

"O c c3

OS OS OS

98-1

C

O.

2: -^ . . <i^

fa e« 3 — ts <

empe

r n

Lo

s -t-> ' - ^

>^o^

onth

-1

99

. o "^ w <N u

Figu

av

er:

(3^) 3jn;BJ3dui3X

19

c o

tat

a. u .c c o 2 u bO C3

> <

1

^m^

o o o « 0 0 OS OS V _ H

c

tio

t«

o. u u a. 1 T

« o o o <N OS OS OS ^ - 1

C

tio

« &. u u

Q.

1

t 1

a o

(U OX)

> 03

fe ex B o o CO C o CO a u CO

1 3 ts o o o rsi

I OS OS OS

Ti c

0^ OS OS

O o X

I 0 0 ON

fe z

^ CO

. 2 CO

1 ^ • S T e<3 fe ON c o - ON

u ^

• 4 — >

C3

(UID) uopBjidpajj

20

CHAPTER III

MATERIALS AND METHODS

Experimental Design

During summer of 1998, 15 60m x 60m ungulate exclosures (5 exclosures in each

of 3 different habitats - MC, PG, and PJ) were erected on BAND (Figure 3.1). Each

exclosure contained an unfenced reference area of the same size. In October of 1998,

two sets of plots (designated 'A' and 'B') were established in each exclosure (Figure 3.2).

In the PJ and PG sites, plot 'A' consisted of 12 experimental units 1-m^ in size whereas

plot 'B ' consisted of 16 1-m units. Because of vegetative complexity and diversity,

experimental units in MC sites were 0.25m . Sixteen 1-m experimental units were also

placed in paired reference areas. Two of these units were randomly selected to serve as

non-treatment controls to the non-treated units inside the exclosures in an effort to

determine the effects of ungulate exclusion.

Experimental units were delineated using a 30-cm aluminum stake in one comer

and a 20-cm spiral adobe nail on the diagonal comer. A 1 -m buffer strip was maintained

between experimental units to reduce confounding effects between treatments or from

researcher impacts. Detailed plot layouts for each exclosure can be found in Appendix A.

A two-factor factorial, randomized block design (Steel and Torrie 1980) was used

to evaluate the impacts of clipping, trampling, and their interaction. Treatment plot 'A'

was established to determine impacts of treatment intensity at 3 clipping intensities [none

(0%), moderate (40-60%), or heavy (100%) standing crop removal] and four trampling

intensities [none (0 footfalls/m^), light (5 footfallsW), moderate (25 footfalls/m^), or

21

heavy (100 footfalls/m^)] after a single treatment application. Treatment plot 'B' was

established to determine impacts of treatment frequency. Clipping treatments in plot 'B '

were applied at 100% standing crop removal at none (0 times), light (1 time), moderate (2

times), or heavy (3 times) frequencies whereas trampling was applied at 0, 5, 25, or 100

footfalls/m at none (0 times), light (1 time), moderate (2 times), or heavy (3 times)

frequencies, respectively (Figure 3.3). Clipping intervals in plot 'B ' were 2-3 weeks. A

split-plot arrangement with time as a subplot factor allowed for analysis over the two

years of the study. Treatments (clipping and/or trampling) were randomly assigned to

experimental units (Im /0.25m plots) within each block (exclosure).

Clipping was used to simulate grazing. All vegetation within an experimental unit

was clipped by uniformly removing portions of each plant within the unit at the

prescribed defoliation level. Clipping treatments were applied prior to trampling

treatments.

Trampling was simulated using an artificial hoof cast from dental acrylic (Pro

Orthodontic Services - Racine, Wisconsin) molded from the front hoof print of an elk

(Acorn Naturalists® - Tustin, California). Two of these artificial hooves were securely

bolted to the bottom of a pair of sandals which could then be strapped on the feet of the

investigator. The average front hoof load of an elk is approximately 685 g/cm^ (Telfer

and Kelsall 1984). For purposes of this study, applied hoof load was calculated to be in

the range of 673 - 818 g/cm^. This design attempted to emulate the rocking or churning

effect caused by a hoof when the animal is walking which has been overlooked in other

simulated studies where mechanical devices have been used (Warren et al. 1986). The

action of hooves may be important in rupturing the soil surface and breaking up litter

22

which aid plants in obtaining water and nutrients (Balph and Malecheck 1985).

Trampling in the mixed conifer plots were applied to a fiill Im area even though effects

were measured only on 0.25m^.

Pre-treatment data were collected and treatments were applied in January through

May 1999 when elk normally would use each habitat type. Post-treatment data were

collected and treatments were applied again during the same time periods in 2000. Post-

treatment data for the second year of treatment applications are not included in this study.

Parameters measured included density, foliar/litter cover, basal area, productivity, species

richness, and composition. Plants were identified to the species level. Unknown plants

were collected in the field and numbered for later identification. If no specimens outside

plots could be located, individuals were marked inside experimental units for later

identification once the plant matured.

Parameters Measured

Density. Complete counts were made on a species-by-species basis to determine

the density of each species for the total area sampled (Brown 1954). For small, numerous

species (e.g., white clover [Trifolium repensj) total numbers were counted up to 100

individuals and approximated to the nearest ±25 individuals thereafter. Species

connected by rhizomes or stolons (e.g., wild strawberries [Fragaria americana]) were

counted as individuals if plants did not appear to be obviously connected.

Foliar/litter cover. Cover estimates were determined using a 10cm x 10cm grid

cell system (Daubenmire 1959). Foliar cover was determined by estimating the number

of grid cells covered on a species-by-species basis. Litter was not measured in 1999 as a

23

species category and is analyzed for 2000 only. We did not attempt to separate litter

from overstory sources (e.g., ponderosa needles, aspen leaves) or other vegetative

material that could have originated outside our plots. Piilon-juniper sites had more litter

than normal because a "cut-and-slash" treatment was applied by management at BAND

inside exclosures and adjacent reference areas as part of a watershed restoration study.

This study was aimed at evaluating vegetative responses to slash as a soil stabilizer and

precipitation interception technique but was not a component of our research. Though

slash was removed from our plots prior to initiation of our study, much litter fi-om those

trees remained in our plots.

Basal area. Calipers were used to measure basal area of individual plants (Brown

1954). During spring 1999, maximum width, perpendicular width to the maximum,

transect width, and distance from the edge of the quadrat were recorded for >5 plants on

>2 line transects spaced at 10-cm intervals across the quadrat. We re-measured the same

plants in 2000. Basal area was calculated using the standard equation for an ellipse

(ab*7i) where a = major axis length and b = minor axis length. Three plants from each

experimental unit were randomly selected and an average basal area/plant (cm ) was

calculated.

Species composition and richness. Composition was analyzed using descriptive

techniques. Relative percent composition was calculated for each species within a given

clipping/trampling treatment regime, ranked in order of dominance, and graphed pre- and

post-treatment. Species in which relative composition was <1% of the total in either year

were not considered in these analyses.

24

Species richness was analyzed using the logarithmic relationship discussed by

Shmida (1984) where species richness is inversely related to the log of the sample area:

# Species/log (area).

Standing crop. Complete removal of standing crop in lightly, moderately, and

heavily clipped experimental units in plot 'B' allowed for analysis of productivity among

these treatments. Subsequent visits also provided an opportunity to evaluate re-growth in

these units. Following clipping, vegetation was dried for 48 hours at 60°C and weighed.

Clipped weights from our initial visit in spring 2000 were subjected to analysis to

determine what effects, if any, clipping/trampling treatments from 1999 had on total

standing crop (i.e., productivity).

Analysis of variance (ANOVA) and mean separation were used to determine

treatment effects within and across habitats for total density and foliar cover. Habitat

effects were tested using the Type III mean square for block (habitat) as an error term.

Potential block (exclosure) X treatment interactions were tested using Tukey's test for

non-additivity. When sub-divided by grass and forb growth classes, density data and

foliar percentages that were not normally distributed were transformed using square root

or arcsine transformations, respectively (Sokal and Rohlf 1995). Experimental units

which lacked a grass or forb class were treated as sampled units and zeroes were added to

the dataset. Basal area, species richness, and litter cover were only analyzed within

habitats. For all analyses, significance was delineated at a = 0.10. We chose this

significance level in order to reduce the chances of committing a Type II error (failing to

reject the null hypothesis when it is false) which we felt was more probable after only a

25

single year post-treatment than committing a Type I error (rejecting the null hypothesis

when it is true).

26

Elk Exclosures Trails

^ / F o r e s t Roads 289 and 142 Highways Bandelier National Monument Major Creeks and Streams Bandelier Wildemess Dome Wildemess

LJ A/:

0

0

4 Kilometers

4 Miles

Figure 3.1. Exclosure locations at Bandelier National Monument, New Mexico. Exclosures (5 in each of 3 habitat types - MC, PG, and PJ) are 60m x 60m with a paired, unfenced reference area of the same size.

27

s o

DDD ^ DDD,2

DDDD DDDD DDDD DDDD

o

O U

Q

U Z

" o to

2 c = (rt u y

x> — i-i a>

S i2 ^ CO O w

^ c cd

. o a v» C O •<—I

^ " (U

- s § *§ fe " ^ c3 c

•*-• «^ t o

^ rr> • ->

i3 -s ^

;3

>

W X

c« cd

CO S:

s .a CX ^

i H

X £

(N

00 CO

CO

W CO

3 Si CO g

o g X 73

CO " O C CO

J- ' r : C

••->

(L>

CO

-«—• O

C

•fc

o o

28

f^

O H K Z

S H ss

O H J Z

O H Z Z

9 H X h4

O H NJ hJ

O H Z J

^ b ffiS

O H §S

O H Z S

0 H s s

2 H s£

O H NJ S

O H Z K

> ^ /

V / \ /

\ M / \ ^ /

\ © /

\ ^ /

• D D D DDDD

DDD ^ DDDD DDD ^ DDDD D D D ^ D D D ^

>> > s

II

n o ^ ^ 1

o

II I I

-

^^

igh

II

k ^ o^

4>

II

&£

plin

=

Tra

in

H &X)

Gra

11

ing

• U tJ

/, fli Cd

CO C r v

CO J5 j_i

S O cd »- JT? " T ; ^ CQ 2^ ^

^ ^ S . > "5 CO*

?? ^ S «

osun

id

he

% s

ti et

irr

— B O W o Cd g WH X - 2 -^ « 1 ^ S

. « <l> TS

IS i

ns

mod

pp

lie

, tw

o

O -5 g C "H-^ 1> . a ^ r 2

g tr

eai

ftra

m

ppin

g )0

foo

iplin

ie

so

Cli

orl

(

ed CO S m

- g i ^ X 1 -S ^

nofc

lipp

i ea

vy)

and

(0,1

,2,0

ap

plie

d ai

o J : 00 s • rt r^ Cd

1 C-^ ^ .1 '" 1 g CO u 5 •--^ Id 2 "o.

( ^ o Cd i 3 r n £ GO "^

Fig

un

(non

e cl

ippi

w

here

29

CHAPTER IV

RESULTS

The following results are indicative of first-year post-treatment data. Initial

treatments were applied following preliminary data collection in spring 1999 and first-

year post-treatment data were collected prior to reapplication of treatments in spring

2000. Second-year post-treatment data will not be collected until spring 2001.

Intensity Studv

Analyses (ANOVA) of pre-treatment plot data revealed block (i.e., exclosure) X

treatment interactions (Fi,43 = 31.61, P<0.001) for density in the PJ habitat type as well as

for foliar cover in MC (Fi,43 = 4.09, P = 0.049) and PJ (Fi,43 = 22.46, P<0.001) habitats.

Initial block X treatment interactions were also detected in PG habitat, but removal of

exclosure PG-5 that had been bumed in 1998 and exclosure PG-1 that had been bumed in

1999 remedied this effect for both density (P = 0.334) and foliar cover (P = 0.226)

estimates. Because differences among habitats existed before treatments were applied,

pre-treatment densities or foliar cover estimates were used as covariates in analysis of

covariance (ANCOVA) for subsequent analyses. Litter and basal area were analyzed

using ANOVA. All pre-treatment data for total density, foliar cover, and species richness

were normally distributed except for foliar data in the mixed conifer zone. Litter data

were normally distributed in MC and PG habitats, but failed to meet normality in the PJ

zone. Attempts to normalize these data via transformation were unsuccessful and litter

30

resuhs for the PJ habitat type should be interpreted with caution. Summary statistics for

parameters by habitat can be found in Appendix 'B' .

Habitat Effects. A significant habitat effect (F2,io = 15.39, P = 0.001) was

detected for density data with more plants/m^ in MC than in either PG or PJ habitats.

There was a significant habitat by trampling interaction for foliar cover (F6,iio = 3.23, P =

0.006) indicating that trampling treatments were not having the same effect in each

habitat (Figure 4.1). Moderately trampled experimental units in PG sites had

significantly higher foliar cover ( y = 25.7%) regardless of clipping intensity. In contrast,

moderately trampled plots in the MC habitat had significantly less foliar cover ( y =

6.7%) than any other trampling treatment regardless of clipping intensity. No other

significant differences were detected in density or foliar cover for clipping, trampling, or

their interaction across all habitat types.

PJ Habitat. We detected a significant clipping effect (F2,43 = 3.55, P = 0.038)

regardless of trampling intensity for density measures. Mean separation of adjusted

means indicated that heavily clipped plots had higher plant densities than moderately

clipped or undipped plots (Table 4.1). There was a trampling effect (F3,43 = 2.33, P =

0.088) on foliar cover. Moderately ( y = 10.1%) trampled plots had less foliar cover than

lightly trampled units ( y = 12.9%, P = 0.031), but heavily ( y = 10.4%) and non-trampled

( y = 12.1%) areas were not significantly different from either one.

Analysis by vegetative type revealed a significant effect (F3,43 = 2.50, P = 0.072)

of trampling intensity on total forb cover but not on grass cover. Lightly trampled plots

had higher forb cover than heavily trampled and moderately trampled plots (Table 4.2).

31

Clipping had a significant effect (F2,44 = 3.46, P = 0.04) on litter cover in the PJ

habitat; however, data were not normally distributed and results should be interpreted

with caution. Mean separation revealed greater litter cover in non-clipped plots than in

heavily clipped areas (Figure 4.2, Table 4.3).

Relative species composition changed. Blue grama (Bouteloua gracilis) and

deervetch (Lotus wrightii) increased across all treatment combinations in 2000 whereas

mountain muhly and yellow ragweed (Bahia dissecta) decreased. However, this

difference was relatively consistent regardless of clipping/trampling treatment.

Snakeweed (Gutierriza sarrothrae), on the other hand, tended to increase as

clipping/trampling intensity increased. This may indicate a possible treatment intensity

effect (Table 4.4).

Mean basal area/plant was lower in 2000 than in 1999 (Fi,48 = 10.02, P = 0.003)

across all treatments probably due to abiotic (i.e., climate) factors. However, no effects

can yet be attributed to clipping, trampling, or their interaction.

PG Habitat. Trampling affected plant density (F3,2i = 4.14, P = 0.019) regardless

of clipping intensity. Non-trampled units had a significantly lower total density of plants

than lightly, moderately, or heavily trampled units (Table 4.1). Trampling intensity also

had a significant effect (F3,2i = 4.10, P = 0.020) on total density of forbs. Non-trampled

units had significantly fewer forbs than lightly, moderately, or heavily trampled units

(Table 4.5).

Trampling had a significant effect (F3,22 = 2.51, P = 0.085) on total litter cover.

Lightly trampled units had significantly more litter cover than non-trampled and heavily

trampled units but did not differ from moderately trampled plots (Table 4.3).

32

Species compositional shifts were evident with a few select species. Westem

wheatgrass (Agropyron smithii) proliferated in response to moderate levels of trampling

as it shifted from 13.1% of total community in 1999 to becoming the dominant species at

29.6% in spring of 2000. Trailing fleabane (Erigeron flagellaris) increased with

increasing trampling intensity and moderate levels of clipping. Heavy clipping and

trampling had a deleterious effect on Arizona three-awn (Aristida arizonica) as it

decreased in relative composition (-2.28%) compared to an increase (+7.96%) when no

treatments were applied. Goosefoot (Chenopodium spp.) disappeared from all

treatments. Golden aster (Chrysopsis villosa) decreased (-3.23%) in relative composition

at the highest levels of clipping/trampling. However, it appeared to be more sensitive to

trampling as decreases in its relative composition increased at greater trampling

intensities (Table 4.4).

Mean basal area/plant was significantly lower in 2000 than in 1999 (Fi,24= 3.65, P

= 0.068) as a probable result of abiotic factors, but no significant changes in mean basal

area/plant or species richness were detected for clipping, trampling, or their interaction.

MC Habitat. Clipping X trampling treatment combinations had a significant

effect (F6,22= 2.34, P = 0.048) on total foliar cover of grasses (Figure 4.3). There was an

increase in grass cover at moderate intensities of trampling coupled with moderate

intensities of clipping. For all other clipping intensities, grass cover decreased at

moderate levels of trampling. In addition, clipping had a significant effect (F2,44 = 2.52, P

= 0.092) on litter cover. Non-clipped plots had significantly more litter than heavily

clipped plots (Table 4.3).

33

Trampling had a significant effect (F3,43 = 2.25, P = 0.096) on the total number of

species. Lightly trampled plots had more species ( y = 10) than heavily trampled (y = 8,

P = 0.032) areas, but not than moderately trampled ( y = 9, P = 0.132) or non-trampled

( y = 10, P = 0.845) sites.

Shifts in species composition were pronounced. Wild strawberry decreased in

relative composition at intermediate levels of clipping and trampling, but increased at the

extremes. White clover increased (+4.8%) at the highest trampling intensity, but

decreased at all other levels. In addition, it increased 2.7% in non-clipped units, but

decreased about 2.5% when moderate or heavy clipping was applied. The relative

contribution of bluegrasses (Poa spp.) increased with increasing clipping intensity

(+1.0%, 1.2%, and 3.7% for none, moderate, and heavy clipping, respectively).

Moderate intensities of clipping and trampling increased the relative contribution of

sedges (Carex spp.). Pussytoes (Antennaria spp.) increased with increasing clipping

intensity (+1.0%, +1.2%, and +4.2% for none, moderate, and heavy clipping,

respectively). Heavy intensities of clipping increased the relative contribution of

fleabanes (Erigeron spp.){-^A.9%) and Westem yarrow (Achillea lanulosa) (+1.1%).

However, when combined with the heaviest intensity of trampling, Westem yarrow

increased 0.8% in relative composition compared to a 4.7% decrease when no clipping or

trampling was applied. For relative changes in dominant species, see Table 4.4.

Mean basal area/plant was significantly less in 2000 than in 1999 (Fi 48= 27.06,

P<0.001). No other significant effects for clipping, trampling, or their interaction were

detected for any other parameter.

34

Frequency Studv

Two experimental units in exclosure 'PG-3' that were not supposed to be clipped

were excluded from analyses because the wrong treatments were applied in 1999. Due to

the resulting unbalanced design, non-clipped plots were excluded across all habitats or

within the PG habitat during analysis.

Pre-treatment data had block X treatment interactions for density data in PJ (Fi,59

= 4.11, P = 0.047) and MC (Fi,59 = 44.44, P <0.001) habitats. Initial block X treatment

interactions were also detected for density in the PG habitat, but removal of exclosure

PG-5 that had been bumed in 1998 and exclosure PG-1 that had been bumed in 1999

remedied this effect for density estimates. Block X treatment interactions were also

discovered for MC (Fi,59 = 5.93, P = 0.018) and PG (Fi,2i = 6.10, P = 0.022) foliar cover

data. In addition, a clipping effect prior to any treatment application was detected in PJ

foliar cover data indicating randomly selected plots differed prior to any treatment

application. Therefore, analysis of covariance (ANCOVA) was used in subsequent

within-habitat analyses, with the exception of litter cover and basal area, to account for

initial differences among plots. Baseline density and foliar cover estimates were used as

covariates. With the exception of density data in the PJ habitat, all initial data were

normally distributed. Summary statistics for parameters by habitat are presented in

Appendix C.

Habitat Effects. Plant density differed among habitats (F2,io = 12.06, P = 0.002).

Mixed-conifer sites had more plantsW ( y = 402 plantsW) than PG ( y = 89 plants/m^)

or PJ ( y = 45 plant/m^) sites. Total foliar cover did not statistically differ (P > 0.1)

between habitats.

35

PJ Habitat. No significant changes in total density, foliar cover, mean basal

area/plant, or species richness were found for clipping, trampling, or their interaction at

any frequency. Mean basal area/plant was significantly lower in 2000 than in 1999 (Fi,64

= 5.60, P = 0.021), but this could not be attributed to any treatment combination. Litter

cover results were non-significant; however, data were non-normal and should be

interpreted with caution (Figure 4.4, Table 4.6). When subdivided into grasses and forbs,

no significant differences in densities were found (Table 4.7). Standing crop weights

were also non-significant (Table 4.8).

Changes in species composition were few. Blue grama decreased at the highest

frequency of trampling (-14.5%) compared to moderate (+0.2%), light (+2.7%), or no

(+0.1%) trampling. In conjunction with the decrease in blue grama, there were

substantial increases in purple three-awn (Aristida purpurea) across all treatments

regardless of frequency of treatment. Snakeweed was negatively affected by increased

frequency of clipping. Change in relative composition between years steadily increased

from -0.3% with no clipping to 4.0% at the heaviest frequency of clipping (Table 4.9).

PG Habitat. Total grass densities were affected by clipping (F2,2i = 2.63, P =

0.096). Units clipped 3 times had higher densities than those clipped twice. Units

clipped only once were not significantly different from those clipped 3 or 2 times (Table

4.10).

Clipping X trampling treatment combinations had a significant effect (F6,22 =

2.43, P = 0.059) on total litter cover (Figure 4.5). Litter cover was negatively correlated

with clipping frequency at moderate frequencies of trampling. In contrast, at high and

low frequencies of trampling litter cover was highest at moderate clipping frequencies

36

but declined at the extremes. When no trampling was applied, low fi-equencies of

clipping had more litter cover than moderate or high frequencies of clipping.

With the exception of a significant year effect (Fi,24 = 11.50, P = 0.002) for basal

area measurements, no other significant effects were detected. Mean basal area/plant was

significantly lower in 2000 than in 1999, but this was probably in response to abiotic

factors and could not be attributed to treatment applications.

The most notable change in species composition between 1999 and 2000 occurred

with the complete loss of goosefoot species across all treatments. Mountain muhly

increased (+9.5%) at the highest frequency of trampling as well as with the highest

clipping/trampling treatment combination (+13.5%). Sages (Artemisia spp.) showed the

greatest relative increases in composition between years at moderate frequencies of

clipping (+15.5%) or trampling (+14.6%), but tapered off at the extremes. Westem

wheatgrass showed the greatest increase in relative density at the highest frequency of

clipping (+5.8%) or trampling (+4.8%) with changes between years being comparative

among the other treatments. Finally, little bluestem (Schizachyrium scoparium)

decreased in non-trampled (-5.2%) sites or when only trampled once (-4.7%). At

moderate frequencies of trampling, composition of little bluestem did not change between

years (6.7% and 6.0%) in 1999 and 2000, respectively). However, at the highest

frequency of trampling, it increased in relative composition (+3.0%) in spring 2000 when

compared to spring 1999 (Table 4.9).

MC Habitat. No significant effects were detected for density, foliar cover, or

litter. However, total grass foliar cover was affected by clipping frequency (F3,59 = 2.83,

37

P - 0.046). Non-clipped areas had higher grass cover than heavily and lightly clipped

plots (Table 4.11).

Total species richness was affected by clipping X trampling treatment

combinations (F9,59 = 1.98, P = 0.057; Figure 4.6). At light and moderate frequencies of

trampling, species richness increased when coupled with moderate frequencies of

clipping, but decreased at light and heavy clipping frequencies. In contrast, no trampling

or heavy trampling frequencies showed the exact opposite effect with a decrease in

species richness at moderate clipping frequencies and an increase at light and heavy

levels. When no clipping was applied, treatments where no trampling was applied had

the highest number of species ( y = 10 species/0.25m^) followed by light ( y = 9

species/0.25m^), moderate ( y = 9 species/0.25m^), and heavy ( y = 8 species/0.25m^)

frequencies of trampling.

A significant clipping effect (F2,43 = 2.44, P = 0.099) was also found for total

Standing crop. Standing crop was lower for heavily clipped plots ( y = 7.93g/0.25m , P =

0.050) than lightly clipped ( y = 10.59g/0.25m ) areas. Moderately clipped sites had

higher productivity ( y = 10.30g/0.25m , P = 0.083) than heavily clipped areas, but they

were not different from lightly clipped areas (P = 0.828; Figure 4.7). The only other

significant effect detected indicated that mean basal area/plant was significantly lower in

2000 than in 1999 (Fi,64 = 52.18, P<0.001), but this could not be attributed to any

treatment and was probably the result of abiotic influences.

Increased frequency of clipping had deleterious effects on bluegrasses {Poa spp.).

They decreased from +21.5%, +2.0%, -2.5%, -2.3% for no, light, moderate, and heavy

clipping, respectively. The opposite occurred with trampling as they increased by +0.3%,

38

+1.5%, +9.7%), and +8.0% for no, light, moderate, and heavy fi-equencies of trampling,

respectively. In contrast, rushes (Juncus spp.) were negatively affected by the highest

trampling fi-equency. They decreased by -7.2% compared to -0.6%) and +0.5%) for

moderate and no trampling, respectively. Junegrass increased (+3.7%)) at the highest

frequency of clipping whereas white clover showed the greatest increase between years

(+4.7%) at light levels of trampling (Table 4.9).

Reference Area Analysis

Despite removing 2 exclosures that had been bumed during the course of the

study (i.e., PG-1 and PG-5), analyses of pre-treatment data revealed block X treatment

interactions (P = 0.034) for density data in the PG habitat type. Analysis of covariance

(ANCOVA) was used in all subsequent analyses, with the exception of litter cover and

basal area, to account for initial differences among plots. Pre-treatment density and foliar

cover data were used as covariates. All initial data for total density, foliar cover, litter,

and species richness were normally distributed.

Habitats were different from one another in terms of density (F2,io = 8.48, P =

0.007), litter cover (F2,io = 40.89, P<0.001), and richness (F2,io = 30.95, P<0.001).

However, no habitat X treatment interactions were significant for any parameter

indicating that treatments were having the same relative effect regardless of habitat. As a

result, treatment effects are reported by parameter and not individually by habitat.

Total densities among habitats were significantly different from one another (F2,io

= 8.48, P = 0.007), but no habitat X treatment interactions were detected (F2,io = 0.86, P

= 0.453). There were more plantsW in MC ( y = 429) than in PG ( y = 77) or PJ (y =

39

45) areas. No differences in total densities were distinguished (P = 0.564) inside versus

outside exclosures (Table 4.12).

Surprisingly, no significant habitat effect was detected for total foliar cover (F2,io

= 0.74, P = 0.500) indicating there were no statistical differences in total foliar cover

among habitats. This was likely due to fewer, large bunchgrasses in MC sites compared

to PG and PJ habitat types. In contrast, MC sites had more, small forbs and numerous

grass blades due to the presence of sod-forming grasses such as Poa species. Total foliar

cover was not significantly different inside versus outside exclosures (Table 4.13). In

contrast, litter cover did exhibit a significant habitat (F2,io = 40.89, P<0.001) effect with

MC sites having more ( y = 68.6%) litter than PG (y = 23.2%) or PJ (y = 7.1%) sites.

Differences in percent litter cover were not significant (Fi,io = 0.23, P = 0.640) inside

versus outside exclosures (Table 4.14).

Without surprise, a significant year effect was detected for basal area in MC (Fi.io

= 15.68, P = 0.004) and PJ (Fi,io = 6.01, P = 0.040) sites, but year did not interact

significantly with treatment in any habitat. Mean basal area/plant was not different inside

versus outside exclosures for any habitat.

A significant habitat effect was detected (F2,io = 30.95, P<0.001) for total species

richness indicating absolute numbers of species differed among habitats. However, no

habitat X treatment interaction was identified and plots inside exclosures did not differ

from reference areas in terms of total species numbers.

Relative species composition showed some dramatic results. In PJ habitat, blue

grama decreased by >30% between years outside exclosures compared to a >7% increase

inside exclosures. Some species [e.g.. galleta (Hilariajamesii), minute muhly

40

(Muhlenbergia minutissima), and sand dropseed (Sporobolus cryptandrus)] appeared in

reference areas in relatively high proportions after not being recorded there the previous

year. Similarly, Indian paintbrush (Castilleja Integra) was the only species that appeared

inside exclosures. The only noticeable changes in species composition in PG habitat

included the disappearance of goosefoot (-21.6%) and a relative increase (+5.4%) in

Arizona three-awn inside exclosures (neither species was recorded in large numbers in

either year outside exclosures). In MC sites, bluegrasses appeared to receive the greatest

benefit when protected fi-om grazers. It showed a relative increase of 15.5% between

years inside exclosures compared to only an 8.5% increase outside exclosures. In

contrast, sedges appeared to be inhibited when excluded from grazers. They showed a

6.0% decrease in relative composition inside exclosures versus a 0.5% increase outside

exclosures. Pussytoes and strawberries may also benefit from grazer exclusion.

41

u • • • I

H: T

O

o

o o in -r o

J 2

O cd ^ -C SO o C —

00 "* ^ - ^ CO

C ^ D C -*-> " ^

00 £ C cd

S ^ Cd KO o

O

o

(A

e

OX)

e a E CQ

H

(04) J3A03 JBjIOJ UB3J\[

CO

o

cd

cd

cd

CX CO

^ ^' fCd

Cd o <L>

2 « g o >

o o cd

CO

CO

cd

(O O 00 ^ '-2 — cd cd »o

s -no .=:

CO .«_<

-O^ cd

(L) •a o

. X 00 ^

00

CX

. ) ^ Cd

> Cd

42

men

t • « - '

cd u u • ^ j

00 C

ram

plii

and

ti

00

c

ippi

o t ^ o

o CO

_(L)

. ^ CO

c <D •«-»

• * — >

C ( - 1 fli

iff(

-a ;_, a

• 4 — •

cd ."ti X5 Cd

by

h

/ « ^ * S ,

o CO

-+ s CO

plan

ti y

(#

nsit

ande

E

- * — > CO

4.1.

A

dju

"abl

e

t-^

6 o >< w S ^

c:

Mon

umi

iona

l N

at

lier

ia

nde

1

2000

in

atio

ns i

n om

b

o

BIT

AT

<

CX

H <:

AB

IT

K O CX

H

HA

BIT

A

c 4

?? 001

and

Me

ampl

in

t -C o ^

^

tens

i in

g In

l

CX Ci.

;S U

{ e a

x;

1 c e k

c

. ^ W5

(U

^

Of c 'S .a U

1

c

nsitv

In

te

00

Cli

ppin

z

s

K

M

3 'oo H . t ;

= 1 3 2 5 is 0 '^

z.

s

E

na iv

iean

am

plin

g)

2 a

z

s

ffi

liai

iip

Uii

g

Inte

nsit

y

eo 00

^-«, vo

^ < ^ i n vo

4j^

37

±6.

22

^ - so

>/^ VO +1

eo

OO

o~ CN

00 1^ ^

, ^ r ^^

^ J : 4

^ vo

So t^ -H

337

a 35

0 48

.1

4j

vo ^ . 0\ oo CN ^

^

366

48.1

8)

4j

eo VO

^ — V

O C3S < ^ m vo

47

±6.

33

^-^

+1

CO 10

3

rT ^ oo o r;:

^

, ^ vo (N

00 r-

^

f

127

17.1

-H

324

a

^,^

303

48.1

±j_

vo < . — od m T^

^ ^

333

48.1

3)

CO

i n

, _ v

r--vo ^

4}

41

±6.

35

^-^

VO " ^ •n vd

-H

eo

OO

^ .-^ CN

Ov ^

^

^.^ 00

^ f ^

^ : :

5, r^

oo i;; ; ^

31

7a

S:

319

48.3

4j

oo

O 00 CO r f

^ ^

352

48.3

0)

• J

eo OS

, , 1 . ^

VO O S < ^

4j

47

±6.2

4

, , fN

fN <N *r\ vo

-H

X>

^ >n

<-> "^ o ^ '^ ( N

4j

^.^ »-

^ -^

' • ^

4j

r^

^ 5 4^

360

a

o~

355

48.3

^ ^

i n

• ^ 00 m Tt

-H

379

:50.

36)

:z;

^

rn

eo

>n

eo

eo m r~

91

a 3

31

a

eo >n

CO

357

a id

Mea

n pp

ing)

G

ran

(cli

zA

sitie

i

c u -o

!nt(

1999

) tr

eatm

e pr

e-tf

or

coun

o eo 1/3

;dm

ea

OV

A a

djus

t(

AN

C

( Q

fN ^ ^ j - ^

>% > eo 0)

x: "~^ o o

dat

ap

plie

Vi eo ^

ling

^

Cl. 6 CO

is Ji X ^

"eo > 2 I-I

en.

cro

00

c c eO c/3

- ^ . 4

c: ne

) pe

r

o c

rate

), o

r 0

(mod

e 0-

60

heav

'—

100

lied

at

ling

was

app

C

lipp

X I

rea.

r

unit

a

Is p

e ot

fal

e)fo

c

(no

o I-I o

rate

), 5

(li

gh

mod

e

^^

, o

d II eO

X

"eo

eO

"c u I - I

^ •3

stic

ally

• 4 - *

eO

er a

re n

ot

me

letti

ith

the

sa

atm

i th

in tr

e d

mea

ns (w

il G

ran

u

43

c • ^m

"H, B cd VM

•4—>

T3 C cd 00 c • ^ D, a

^ • ^

o (^ o CO (U

•4—>

ens

U 4

iffe

T3 i ^

.O

type

f

* -4—>

Cd

00 >%

^ ^^^s

dj CO

4

s ^ —

> o o u< cd

'..in a c cd (U

£ «

sted

=3

TD <

r i ^" (U

^ ^ ^ cd

H

6

S ^

^ "c (D B C o s

^ ^ cd

o • J cd Z

U l (U

^ • ^

c: cd OQ

'

o o CN ,,_, cd

-4—>

3 cd X 1 — J

PLH

c "" CO

o ' • 4 - '

Cd

C ' ^

o o

• 4 — •

(U

£ •4—>

Cd (D

• 4 - '

00

w on

c eo U

S eo I-I

o

'oJo c

"E 6

tra

eo -'"-ON

vq d +1 vq t^

oo^ c 'B. .g. u

S3 VrJ CO 00

S <s 2 i3

c

'5. .g. u

00 .^ •S .-^

eo -S

i n fN

o fN

od

OS

4j^

fN

eo

o?

d

oo d -H

fN

O O

d

vq fN

oo

d -H

CO

oo" vo

d 41^

vq

00

-H

OS

4|^

0(3

oo

oq

eo

d +1

fN OO

d

p fN

OO

d

i n

oo

d -H

CO

d

fN 00

VO fN

0(5 0C5

O fN

o fN

fN 00

d

00

d

CJv

oo d 4j^

fN

OO

d -H

fN

d 4j^

0 \

00

±l_

oo ON

C7\

4j_

fN

VO «N

vd

eo

d 4j_ fN fN

OO

d Ov

oo

d

fN

00 d +1^

cq fN

CO

0\ «n d ±1^ fN

od eo

o" vo d 4j^

Of)

r- eo

o" V O

d 4 ^ i n

eo

d 4j^

i n fN eo

o "

d

r~-fN

CO

d +1

U 00

^ 1 2 o

i n fN

> eo

O

o CO

CX eo

eo

00

c I eo

ji X

"eo > O

B u I-I C14 o 00 c

^ Xi

S eo E -4-*

. C Vi

o

Vi a I-I a > o o I-I eo

OS OS 0 \

C ^

eo

t3

C3 u o I-I

C14

'a? c o c

•4-»

eo I-I

I

o

d

o .i?

CO X

O

> CO

X

o o

eo ii I-I eo

C 3 I-I

Vi U. <z> J2

a c 3 O o CJ CO Vi C eo (U

£ a

• 4 - *

3

eo

< > o u z <

CO

CX eo

CO

00

c

o ,0

ii G

o

o I-I

o

CO

c ii I-I

o

CO • 4—t

Vi -4-*

o a> t-i eo I-I ii

a e eo Vi

ii X •4-»

c ii

CO u is c

X X 00 op ^

i n

<u S eo

e i

«5

c eo ii

B C eo I-I

o

44

.c ti X u

CO

X O

.-2 E

o o

C8

0 D 03 •

R

>^

OO GO

o es 2

«K 2

CQ

ON O o II

et}

*.Q

a:

s

eo e a a

CO cd

CO (U

• * - > . ^ CO

u Ul

cd •4—•

ed Q

CO

C

O O

ed

TD

cd CO

cd

00

c

cd 4> u ed

•5 U 00

"5-

o (D CO C o CO

(4-1 O u O

•4->

cd >^

Xi

c 3 u

a "cd > o £ u

2 o 00 C

i = .5 .o. -K

•4-> * i -t-* »i*r ^m m-i - «

ed 3

ed

x: u ^ c2

£ ^

> o o u

cd

T3 C ed ed

u ed

CN

fN O cd

C

o (U u CO ed 00 (u

£ £

c

a. c o c

u o

•4—>

cd u a>

I D O

O VO

I

o

> ed (U

JZ

— I —

o o o

00

o o o

vo o IT)

o o

m n (o/J J3A03 J 3 W n

45

nati

ons

B o o

•4—>

c £ • 4 - ^

ed

I-I • 4 — •

M l _C ^ • ^

ram

p

• * - •

•o i

clip

ping

o

a

les

ensi

t

-4-J

eren

t in

fe

t fo

r di:

Cd -4—>

.) by

hab

i ' ±

s.e

£

love

r (%

/

u I-I

•4—<

. —

c Cd <D

S

ble

4.3

ed

H

CO

. N

ew M

e m

ent,

3

iona

l M

o

- 4 . ^

Cd z I-I

'.. U

-o § m

2000

-

c • ^ N

O

H

AB

ITA

X <—> CX

AB

ITA

T

PG

H

<

MC

HA

BIT

ind

Mea

n

1-

O

ity

Vi 3 ii 3

)—1

OO 3

o. .g. U

rand

Mea

r

O

C/3

3

ppin

g In

te

Cli

rand

Mea

n

^

Inte

nsit

y

00 3

' a C l .

U

U

an

ram

plin

;

H

ampl

ing)

b^

Z

S

K

tram

plin

g)

Z

^

K

tram

plin

g)

Z

2

K

Inte

nsity

5.4

, ^

en

vd

0C3

od

20.3

12

.1

oo vd vo

6.0

vo

0(3 od T ^ -

7.6

a

1 —

(±2.

1'

_ o i n

od 4j

i n Ov en 4j

17.1

b

i n

^

(±7.

47)

(±5.

80)

60.5

a

89)

i n

5.87

) (±

^ m ^

-H

en

vq f N

-H

K

26.7

-^ en

O

vd

i n

f N

22.3

30

.8

vq

vo

4.4

vo

0<5 T f r

12.0

a

^^•v *—1

(±17

.4

_ i n o -J 4j

oT r-f N 4j_

24.8

ab

m

(±3.

36)

(±10

.30)

68

.0 a

02

)

m

en en ^ +1

vo d ^ +1

S

31.4

i n

i n

q T T

vo vd ( N

31.2

34

.4

vq

vo

4.4

vo

r f

TT m

17.0

a

, «My

f N

(±18

.4

_ OS i n

od -H

^ f N i n

d 4|^

30.7

a

en

(±2.

(±

10.2

3)

(±18

.39)

62

.1 a

56

)

i n

5, i n en 00 4j

fN^

Tt* ^ +1 "

J

10.9

en i n

r-en

oo

ON f N

14.0

11

.3

q od 00

7.4

i n

•«r

od i n

6.6

a (±

2.27

)

^ ^ i n f N (N* 4j

^ - ^ ^ ^

18.4

b

m (±

14

(±2.

00)

f N en

67.9

a

en rsi

3.12

) (±

6.:

W-*

^

i n en

.— 4j

z

^

18.6

1

x> CO Of)

od

eo

q i n

CO

f N

f N

22.0

a

22.1

a

.lab

71

.8 a

en vo

X I

O N

i n

3 eo ^ s

Gra

nd M

e (c

lipp

ing

m f N

—;; >. > CO ii

X

tl0

0(

CO T3

_u

& i CO

Vi eo

00 , 3

^^

tram

p em

oval

whi

le

CX

o

ingc

r •o

cent

Sta

n

I - I

(non

e) p

i

o

-60

(mod

erat

e),

or

o

1 (he

avy)

.

o o -4-> CO

it ar

ea.

per

un

ne)

foot

fall

s

o ^ o

o •4-*

'B' - f i CX CO «5 CO

lipp

ing

U n

op o i n

oder

ate)

g

d

0.1

II CO

. 3

at a

lp]

• ^ - »

diff

eren

>>

tatis

tical

Vi

lette

r ar

e no

sa

me

1

ii X

ent)

wit

h

B eo ii

3 X

"^ Vi 3 eo

rand

me

O X !

3

utio

w

ith c

a rp

rette

d

a

uld

be in

o X

nd r

esul

ts s

i ;s

sful

a

O

wer

e un

su

B "eo

9ZI

*«

P O 3 O

ttem

pts

1

< ( J

46

3 ii

§ CO ii b

tram

plin

g

T3 3 eo 00 uiddi

u C M

o

ities

'

CO 3 ii

3

3 ii

ffer

•5 k .

o c3

^^ Cd •tm^

X eo

X >%

X

o o o f N ai >

as OS Os

_ d - 1 Vi •>

s-g fi Z

§ fi 3 U

^ 3 o S ^ ^ ~~ eo 3 3 O O 4—* '^rf

o Z & i -E .5i 2 i se fi > eo

'13 CQ

CX c:

.4.

atio

i

• ^ 3 1) 3 -2 B

Z

H Z

3 z CXi

S •^

H

o , o

u z o z

o fNl

Os\ CTV 0 \

^ O l

MM

O O f N

c^ C?\ C?\ —"

u

2 u Q o S

o o o f N

0\ OS Os

o o >

> <

O f N

CTs C?\ OS

> H So Z u H Z o z Ni<

CM

u

O O

, , O U z o

f N

Os

'^ o c> —"

u

Q O

O O O f N

OS OS OS

o o >H

> < ti S

O f N

OS 0\ c

1 «

^ ^

u ^

"^ rr < . <N ! : : ^ ' ~ •

^r «n vq Tj- 00 ov in r- od K TT en fN

fN m en

vo 00 r^ in ov vo en f n o o ' _ ' v o i n i n m ' ^ f N f N

* ^ f N i n q — r ^ m o o P 2 2 v d v d f N v d v d ^ i n ^ T r

m

t ~ - ; T t ; q e n e n e n i n f N e n i n ^ t i n ' O v d f N ' ^ c j v T r

* ^ f N ^ v q r - . v q ( N e n q i n 2 2 ^ ! I ^ ' ~ ' ' ^ v d « n r - ^ e n e n

^ . q o v o v i n i n f N * - ^ r ~ — 2 in Tf vd Tt vd in 2 f^ <^

' ^ e n T f ' ^ O N O O o o o o o e n f N

f N f N

r - - r ^ ^ e n i n v o i n T j - - ^

f N r ^ r v i f N O v i n o e n o o d e n o v T t e n i n T r e n — '

^ . o o ^ f N i n e n e n v o o o i ^ ^ T j - J ^ r ^ i n o o m m T r f N

vo m m — TT

2! ' ' 2 "«a- - "* ^ m a c<) <z>

' vd -^ <N

vo

f N

v O ' r r r - ^ f N q o v q — CN r ^ o v ' ^ v o v d e n v d ' ^ T T

Os o o r ^ f N e n c x s r - ' ^ r f N T r

X , v o f N r ~ - T t v o r M v o T r f N

t ^ O v o f N i n v O f N o c j e n i r i o v i n v d v d o d i n o d f N

" ^ e n c s - ^ f N o o T T - ^ o v ^ 22 od i n od vd Tj- Tf' Tj-' rn fN

I I 3

C l , CQ

I

"a

c '5

5 • • • 1 *

a c a

:

5 C3

a

a 00 I

C3

."a a

C3 a K; ^ c ^

s: cj

cu

^ r > ; ' ^ e n o v o q o o q v q T t o o O v d J 2 ; J r n r ^ o d T r r ~ - " e n r r d

* - ? e n O V ' - ; T r r ^ * - ? C ? v — v o P J i ; ^ e n r - ' f N i n r - ^ 2 ' ^ < ^ < N ^

' * 1 * ' l o c 3 e n f n f N f N O O f 5 0 \ 0 ^ 2 2 ^ < ^ < ^ ' ' ^ o v i n — e n d

' ^ ^ r - v o o o o " ^ — — en — S I ^ Z d - i f N ^ d S - ^ - t N -

^ « . r-_ q vq - en r r ^ CT; q ^ ^ — f N i n i n e n o s i S T t d

2 2 2 2 ~ < ^ ' ' ^ « ' v r - i i n ~ i n f N

* - ? ^ v q q c 7 v e n o c > ' ^ f N o c 3 q ^ ^ f N C N f N f N v d [ I I ; o d f N d

•^ "" r~- r- q oc> en vq —. c?\ vo ^ j : ^ fN — <N TT od en T - - *n

^ < . - oo TT en ^ ^ ;

en ov ^ m -"T O

•"• 2 en f N i n Tj-' u-i r f 1 ^ en O

<n oo T f r^ — 00 m o

en _^ —• — en vo in en

—. CTv

^ i 2 '=»•' <N i n TT od ^ ra- r j - o T j - v o o v m — " ^ m e n o

oo oo i n o o e n — j O v - i r t T T C N e n J i ; ; ] i £ e n f N i n r f 2 r n e n e n i n

Os — r^ m 00 m m ^ S^ *rt r^ m so -t

vq T^ f N r f

ci. ^

rige

ron

U j

C3

o

a Hum

b

O

tat

GH

abi

ft.

vo vo

d d f N f N

c a «... c o C3

• O — OO en vo f N en 2

5 •2

q ra- rn in od r^ en fN

S un £0

I: § b O > |

cj

C3

00

a

3 O

5 s

- ^ Cj C3

. N

QQ CO

C3 .CJ

O N

" • • I *

to O

> Cj

•a ^ to .«!

U 03

2 C o •a s

C3

.00 ^

q vo «n

rj- r^ Os m Os !!::! vd - • S d - •

C> en _ . ^ en ^ <_,

;c 22 vd d s -• <N"

vq „ m en

q en en

P vo O * ^ —" f N

f ^ ^ O "^ en -X «N — * ^

en TT en r^

vq

f N

f N

vq «n Tf' f N

CTv O O

^ : * e< rM* ^ O -

rj- «n

en

00 O f N

^ e^ f N ^ en vq «n

r j

^ "^ vo OO vo - J TT — ' ^

Tj- VO

2 d

m r r I " .* m

p? r: > \ z:<^

en •<0-

r j - m Os VO —' ^ r< _• 2 ; - • fN'

en O i n Ov vo ^ i O en ^ 2i e<i d ^ e-; fN

O r- VO vo ' ^ en o\ o; rr" - g - -

^ r- m r- - : ov vo ^ ^ fN d 22 «^ oi

q — en —

q q i n — f N

i n ocj f N —'

•^ ^ Ov vo ^ . O en vo i n _ -f N — ^ f N

Co S

o O ft.

:5 §

Oo Oo

5 2

a

Cj to

c

I

v. 2

vo rr

-s:

5 :=

CX O f .lo N

c: .N

— ^ VJ VJ

IT; Co >~J «5

I

m f N

> eo ii

X^

o o eo

"H. CX eo (/) eo

00 3

I eo

'x

"co > o E

u

o 00 3

•5 3 CO

3 ii CJ k . ii O.

OJ 3 O 3

•3 '^ CO OJ j j CO "O ^

11 o vo

ii

^1 CO 0 :

^^ 3 o o O 3

*- o « I -

T3 O

CX 00 eo -sz Vi -—'

oo ii

0 i

47

c a QO 6

CX '^

o -^ ^^ > o ^ c« '^-'

' w U

§ I •- o

U l

c

U

*- -a

-<-> I

 o >. (N

X ^ •t—>

c« 2 C

^ O

>% - * — < C/5

c: 

c« C

X3 UIO

o .,_, c

- 4—»

cd u

-4—>

M ci; • ^ H

a B cd u

•4—>

C/3

oc

O

3 CO OJ

r! m 1-

o

,_^ 00

lin

u. E CO is

oq 3 'S .n U

fi " . .M CO 0 0 OJ 3

1 i CO I -U - I - "

o ^

00 3

'o. P. u

00

•M -^

CO

CO

vo" en

od

en

fN in

4

m

vo q in

4

in

m

oo r l -

4

OS en

CO

d

vo

o

d

in

fN

d 4I_,

vo

ON

d 4j^

vo

eo

vq od 4j_ oo in

vo

in

4i

fN

i n

OS

i n

en oo

CO

d 4j in

o d ^ ^

vo

o

d

m

o

d

in

eo

^ . od

OS

i n

4

0 0 in

fN in

Tj-'

4

o m 4 oo

eO

d

o

d

in

en

d

in

d

in

CO

in od

f N r l -

m en in 4

o en

vo

in

rr 4 en

i n

d -H

d -H

d

en

en

d +1

eO

en fN

+1 VO r r

CO

fN

-H

CO

en fN r^ -H en m

eo m en d 41

in

CO

m en d in

CO

in en d 4j_ in

3

(U 00

fi ;3 2 ^

O

Vi

3 (U

oT OS Os

3

eo OJ

I

3 3 O CJ CJ eo VI 3 so OJ

E

on 3

CO

< > o u z <

o o CO

. a j

IS, CX eo Vi CO

^ 00 3 I CO

a X

>

i ii I -cx o I -CJ 00 3

"3 3 CO

3 ii o u <u CX

(U . 3 «S

I s ? | U CX CO Vi

<^ CO

O

O VO

I

o

o ,o

3 o 3

ii

— CO " 3 u d. ii Ou 73 CO o

^ E

o d

CO X

• £-^ "eo . 3 •*•*

eo t 3 u

c2i o ^

o 3

3 O

& -^

' ^ u

o ^ o — ** i n CO ^_^

^ 00 3 CX G,

U

i n f N

,. >> > eo OJ

. 3

CO •*-»

eo

T3

o

3 Vi Vi CO

- * — » OJ I

•T3 OJ

en 3 CO

a •4—t o o I -

u I -eo 3

cr C/2 OJ I -3J

^ c2

_eO Vi

O 3 (U u eo u OJ C a a B CO </5 CJ

X

3

CO ii

3

u ^

E ^ -Si" C/3

3 Q

1/5

3 CO OJ

E -o 3 CO I -

a

48

^ WD jS .a

1 e 2 2

Hig

h L

ow

It

&£ a a.

e T

ram

er

at(

Mod

+

plin

g ra

m

NoT

t

• ^ ^ IT)

-r f^

c s

• 4 — •

I-I

o

00 c

e ed u

• 4 — >

S := 60 U

.B Z S c Cd (-1

00,2

-o .2 ^ Id

c« "^

^ - -2 J ^ c« u c« (U e

S C ^ • M — CQ

WDVH O

ac2 o

Vi CX

/-^ o o^ d) ^ *-

> o o o o u cd 73

(D

<2 c ed

c«

o

4=

Id > O

I-I

CX

2 ^ O g 00 «« .S -"S "'5 c

CO ^

cd o d) CH

^ ^ - . ^ ^ > .

©^ ed O D

• :S u O O O

B O 2 ^ (u a?

? - rv

c ^ o ^

So o ^ •4-4 _ r

U O

a - CX o cd ^ cfl ed ed <^ -a 2 ^ w

ed

00 B

. 5 CX CX '^ CX CO

• - = ed

U ^

(o/„) j a A 0 3 JBiio^

49

.833

© II

0M

1

o • o 00

.,_, cd

•4—>

MC

Hab

•

Cd 1

e« ^ H

C3 ^ _

ed

o • o t^

-4-> Cd

•4->

rHab

i

u OH

0

1

o • o vo

"rt

Hab

it

• — > & H

D

1

o • o

m

= 0.

027

eu

1

o • o -^

TT

r-00 •

o II

.fi

.fi

iJ; r/

^ / /

1 1

o o • • o o f* rq

( "l

ct 1

ct j

C 8 ^ "

< ^ ^ vx/v .

' ^ ^ >v>v>

CQ VA

1

o • o

^ ^ *

^ frt

7/ vv

; J ^

• "

-

~

c z> • o

Z

N4

S

s

NJ

S

M

Z

N^

S

K

y H

abit

at

. f i

s

Fre

quei

p

ing

Clip

00

-5 CO C? Cd cd ^ "55

site

s 00

%

CJ —

forM

* ie

d at

cd CX

« e-Q '^ • ^ CO

Cd

ippi

ng f

requ

ency

of

4.

Cli

ppin

g w

pe

r un

it a

rea.

tocl

ct

or

imes

spon

se

by a

fa

eavy

) t

OJ "Q J3 w« ii — e. '^ r^

itat i

i ul

tip

), or

by h

ab

fore

, m

Qde

rate

(%/m

2)

id, t

here

t)

, 2 (m

.

S " 00 > cd ;r:

litte

r c

5m2

ar

one)

, 1

C <N c

. M

ea

on a

O

val

O(

Figu

re

mea

sur

crop

re

(o/„) 43A03 jawn

50

o o o < N

c • wm

Vi

c o

•4->

ed C

• T>H

X 5

B o o

•*-»

c (D

B •4-J

ed d) ^H

+ j

0 0

c ^ ^ H

CX

E ed I - I

•4-»

T 3 C ed 00 c • v*^

CX CX

• ^ ^ • ^

O ^ 4 - 1

o C}

Vi (U

. 1—4

o c d) =3 cr <D

ci: ^^ c <D ^ .<D

^ C+H • —N

-o VH

o C+H • J

ed .4—)

. 1"H

X) ed

42

X f S

£ ^ — WH

> o o I - I

•4—> • —H

^^ c: ed

vd ^* j j

3 ed

6 o • *-H

X

s ^

z c a> B o G O S ed c: o . 1"H

-4->

ed z I - I

« ^ 13 c Cd

H CQ

S

a CX

e I

H < H 1—1

CQ < X <—i

O H

>~v O 3 OJ 3

ii 1—

tx 00 3

'S4 CX

u

c . ca 60

= i

H <

ffl < X u s

>. CJ 3 (U 3

OJ 1—

b 00 3

'S< CX

u

CJ

3 (U 3 O " OJ I -

PX M) 3

'S. .9-u

« '60 U !=

-o E £ « 2 i:

60 >^ C O

; = c

i- = 2 Ji

CN

+1

m K

-H

t » c:> (N —

-H

(N

od r n -H

O <N 0 0 -H

o >n

(N

CO -H

<

-H

O >o

-H

<N r -

so so -H

q 00 06 u-i

-H

P pi

r--

so — -H

ON vo V^ •r i CD 10 —

-H

«N

-H

o o r- so —

-H

o — "O

CO ON p i r i fsi

+1

o vb ro

-H

m So" <N —:

-H

<

so

fN rN -H

O ON VO

vo -H

CO

O ~

-H

T t vq (N CD r~- —

-H

•^ -H

ON 00 — <N - ^ VO —

-H

<N

0(3

__ o

-H

O

-H

CN <N —

-H

m vq 06 v\

-H

ea

CNI O " — <N <N vd

-H

< z ON

00 fN o wS (N —

- H

o — r n O <N r-i —

-H

fN

VO fN fN -H

CQ

Os ON vo

fS 1 ^

•<3-

fN fN VO —

-H

vo f^ — <N r - —

-H

ON

rs >n ON CD vo —

-H

00 vd

— '^ -H

— <N >o —

+1

— ' t

-H

o — d • ^ fN —

-H

vo vd +1

— (N -H

q od

ON fN vd -H

-H

^ 00 vo 10

-H

fN lO >/S — lO —

-H

fN r^ VO —

-H

O fN Of) ON • ^ VO —

-H

00 ^

7.0

f N

0 0

(±2.

02

CO

q f<S -H

4j

C3

^««.

9.9

:2.9

0

X ^ ea ii t -

-H

1.0

f N 1.

9

f N

1.0

"

< z X)

00 00

-H

x>

Os

-H

a

q

-H

vo vo -H

ca

vo ^

d n -H

cit

fN ON

od ^ v o KTt

-H

•^ f N

v o !/•> -H

c ca u

TO c ea

60 c

'n. CX

o' • 4 - . *

CQ

a CX CJ

ed

3

CO

ti a

a Vi

> ea ii

X^ C ed a j

X, m

Cd >

I ii VH C l .

o o

6 0 3

•3 3 cd

O

o ed

T 3 ii

^ a

^ 8 • J- O

3 ii I -

* j ed

OJ ^ - » ed I -u

I CN

X ftO

OJ 3 O

o

ed

c/5

^ - » O 3 <u ^ ed I-I ii

a a B ed Vi

ii

X X

3 4 j

ed OJ

a 3

^ ^

en 3 ed

i 3 ed

U in- O Kl CN .D

O

OJ

OJ Vi

X O

•*i o OJ 3

-O

OJ

^ • " =

CJ X ii ii I -ii

• 4 — •

ed

IS ed

X O P H

3

3 3

ed

O 3

C M o 3 O

I 3 c/i

ed * - > OJ OJ

B

B T3 3 «

6 a ii

cx X ii

Cd

ed

T3 OJ N ed 1 -&0

1

3 0

Z

. K

t — >

cu _s iS ed

Q

51

00

ed I-I

c ed 00 c "a

C X * ^

13 Vi

.2a 6

I o ci3 ^

c z I-I , ^

a c "-S B c2 S

-4—> ed

> .2 cd ed

S> te

^ ^ ed

C « / V

CX ( N

.ti 3 w ed

c ^ cd C (U • -

- I Vi C

< o o l ^

' ^ (U

^ - • ^

J3 ed H

c ed (U 1-4

T3 00 W or) 00

O

VD

O tx

«> 3 ^

S 5

o 3 > CJ 3 >

3 ol ed aj

r ' - ' * -

H tx

ed

o

«n

d

CD

d

d

ed

CN

f ^ CN -H

O

c»

CN

C3N

OO f ^

CN

OS

ed

CN

d

IT)

d

d 4J^ IT)

d

-"it d

vo

ed

o?

f ^ CN

CO

vo

CN

oo

00 rn (N

f ^

^ ^

ed

CN

d ^ ^

d

'd-

d

IT)

d

vo

d 4J^

ed

oo"

m

CN

CN

VO

IT)

CN

+1

OO

CN

CN

ed

CN

d

d

d

d

vo

'd-

d

vo

ed

CN

CN

t o

CN

vo

' d ; CN

4j^

vo

CN 4j

i n

CN

4j_ CN

CN <N

d

4j^

ed CN CN

d -H *-

l O

ed ^—V CN CN

d 41^

>/ cd

- • ' ^ N .

CN CN

d -H

ed 1 -ed

•4^^

'B 3

OJ CX Vi

B '-t^

>% > cd O OS 3 ON ^-^ — o

ii ^ > II

OJ - 5

a ar ": « Vi *•> ii 3

6 ^ > cd ii

X

I-. .22

o -3

3 aj

ed

S I ed o u

a CX ed Vi ed

u 3 O

o

1 O

a o o

ed

O 3 OJ I -ed I - OJ 4>

T3 OJ

Vi 3 ed

O O I -OJ I -cd 3 CT" c/i ii I -dj

C/] ii Vi Vi ed I -00

^ fe

00 3

"E. CN

m Z -x ed

•a e/3 3 ii

Q T3

52

c ed

o O

£ <N ed 0^ d) ON i s ON 00 O c ..-. • s- s o Id »2 .fa

^ 00 00 . £ C3 o .

S ^ a ^ ^ ^ < ^

-H .fa - - :S d ^ -« .2 oO S X

^ ^ ed 4>

2 o g -? I Id ^ 5 •z: ^ c: • f i ^ ^

T. - ^ Op ^ Id «« o == 2 O C5

g &).2 <D I-I

ed z 00 t - i

<D

^ - 1 ed ' ^ ed

^ •4—>

Reg

ro

(D . 1 - ^

Cd J o oi: Cd I-I

> . ^

O O o fs

999

4 - ^

SO

0.5

-+^

2.16

o vo

±0

.

0 0 0 0

II ^

r - s

o CN II c:

CO

0.1

-H

0.26

vo "^ d -H 0 0 T f

S m

o

I-I Cd

W

OX) Cd I-I (U >

>\

o

o Ul

PH

I d

Of cd^ I-I

>

O O O (N

OS Os Os

O O O CN

OS Os Os

ed -4—>

• — 4

- ^

CN

VO

d <N

^ II

CN

VO

^ II

CN

o ^-v - J "^ '^ vo

vo w Ov

'^ vo -+ II

00

U

CN

CN)

CN

-H II

d

ON

(N -H

CN

O OS ^ ^ vd vo -H ? i n 0C5

r-

( ^ ^ ' -H (N ro CO vo

vo fO

l O

-H CNI

vo

^ (N ^ II CN -

O

^ II

CN

-H OS CN

Os

00

o i n Ov u-

ON p -H

O VO

O Px

»n CN

d c: o 0) en ed

X3

o Vi

u

o

O i-i

PH ea

CN I

u t - l

c«

X

ea.

^ T i

£ ed C/3 1

£

(4-4

o Vi Vi

^

O • • - H



X)

tdai

CO ^

O • 4 - '

%

c: (L>

• 4 - <

(D -O

ed >

O

d) o o o

ed >^ ^ ed

a = (D ' ^ N C

a o CX o

£ fa ed o

o -o o I-I CX

"ed

a I-I

5x

CO (U N

.1 -H CO

a i

C/3

53

c o

ea c

o

c

ea

oo

"o. E es

C es 00 c

' 5 . o .

c u 3 cr

c

.1 , o

ca . £ :

X I o o o <N

ON C3N C>

es . a

> u z

RE

QU

E

u. U z ex IJ o

z o Z

LIG

HT

2 u Q O ^

> > j

r - • v

21 vo oo f ^ 00

i n — >n - - —• —• 00 t - ; K fvi «n TT — o

vo <n «N ON

r- r- vd r-

q NO NO f N r~ >n -er r n

CN

vO

q vO 00 ON

ON • ^ • ^ evi

T f TT 00 r~; 00 ( N r-i —

f-N| O — <D 2 1 ON m CNl

O r^ NO vO vO O <n — <n f«i r- f N

' » ' ^ o ' - : q o N O o o m f N 2 od fN >n fN) in rvi - £ r^ w^ - ^

ON — _ i n - 2 ^ -

r - i n •<5- r n fN vO r- vd r n f N

— v o q q — - " r - ^ f - v j i n r - r ^ r o O N O N m v d o ~ i / S — • i n f ' i r v i —

vo NO V O vd rsi f N

m m r^ m f N T T r n f N

vq oes ON —• od i n • ^ f N

ON f N r o ON i n i n fvi f«-i fN rsi

f N O vo t ^ m

X : O vo — ^ vO — ON i n e» 00 r- od r- —

oo vo m o ^SDU^ — ^OsrAOO

ON NO O — O m ' vd f N f N

m — t~-

21 r- NO TT f N

OO NO fn m r~ m Nd O in rn in fN

m 00 00 rn 2 " * NO f N

ON

f N

ON TT r - m od —' i n fNJ T t f N

fO o f N 00 r-~ NO r<-i ^ i n ^ 1/^ -

ON — ( N m od i n r- •<9'

— ^ in 21 " '^

m m fo e?N r o 00 O m O 00

I ej

Ci, O^ ^

5 s

1 S O uj «X QQ

-Si

•o" -Ci

c

C

5 ej

C

I

'. O N r o i n i n . O N O — o r ^ r o O i n r o r ~ ~ f N i o ^ — - — - r o

i n m ^ . — ONr--ONONOONO — m O N O m i n ^ v d v d o d v d o N T j - f N r o f - v i — vn

o J ^ 2 1 f ^ i ' ^ ' ^ O O C 7 N — O f N T T — ~

" ^ . ' . r ^ o v f N f N i n r o O N T r o r ^ f o r o 2 ! ^ O N r - ^ r - ^ o d N d o d r » i f n r o — — Nd

^ 2 1 v d T r r ^ ^ : 2 — O T f i - ; - - : , - ^

I r 2 2 ; v d 2 2 1 ' ^ 2 1 ' ^ - < r f N i d — - r

o ~ 2 o d o d ' » r t - ^ 2 2 i ' ^ O r o — — m

^ i n o d i n ^ f ^ f ^ O N i n f N f N m o

m ON Tt s o

o o m —

I-; 22

m NO —. r o O ~ o i n <=" r n —

NO in fN

00 oo

—

ON

m ro t=>

00

ON

—

m m — ^ m IN

P f^ fo — n •V r-~ <<r t ^

f N / i ^ r~; ^ ^ f N ON r^ 00 f N

s o NO CO • ^

— d

Ov s o m 00

?; - = ^ — f N f N r^ n f N

T T r~ ON r o i n rsi — - ^

r~; ro m

so 0(5

ro m

ro If

cd ro

ON

^m

SO ON

O"

d

o d

oo

d

TT 00 r-

o d

PNJ

r-

fN

q od

•o TT

d

ON C?N

—

18.7

ro • •<r

r-sq —•

so 00 ro

NO in fN

ON in ro

m rsj —•

ro vO ro

^ r^

r-oo fN

•* oo d

m TT

1

1 1

1 1

1

ro r-d

00 —

ON *

in r~ fN

O oo <?N oo ( N r o dl o6 tzi r^ o6 \6

' J r- o — o ro '^i 22 <N d Tf i n fsj 2 [ 2 "" vr^ "^ • « • • " " ' ^ s o ON TT

r o r o r o f N . N O l . ' o O f N O O f O i n T T r o v d — i n 2 1 o d 1 2 1 ' ^ ' S - f N f N — vd ro

ro O

NO ,.0 m fN ro ON O . NO m NO m

TT 2 1 ° " " * • • • • 00 'S- ro ro —

fN

00 O m u-i od in

fN ON

m in in — d -rf

NO ro in

rsi — sd

C3N _ O _ p2i;c^ m

ro CTN " ^ NO _: _: I _:

TT ^ Tt "l

- o; r- £

rsi

d **! oej r-; NO in —; fN ^ r^ •^ r^ 1/^ — •^

00 00 T 00 m r~ m r~ — o fN rsi

TT — 00 ro rr fN

It o ON ro (N ro

; * ^ d r ^ r ^ o E « ^

fN

1^ SO — ro

ro — — vd

ft} -r 00 2 m r-"! — vO "*? — 00

:? od r-; :C - fN

00 NO I^ <N T T

d ;: 22 " >

ON

ro

m r-

r-; od

— "

m • > *

q r-i

1 1 1 1

^

—

•t fN

"IS-

fvi

— d

r~ vd

in

d

C?N

—

vq r-

m —

ro •* Tt — —

2 ro on ON _^ fN

^ 2 Ov ^ Tt ^

00 o; od :£ - -

fN

ro m o —

m vo

rs) — • ON

vd ro oi o ^ j T r o r - c M T t o _ _ _ :

O N v O v O f N — r ~ - r o i n r o s O r o r ^ r ^ v d r - ^ s d ^ r o r s i f N — —

ON 00 r^

SO f N — f^ r o — — '

f N e» f N sq • . t vq

i n f N

r o r o NO 0 0

d d

f N f N NO O f N f N

^ SI

1 .

-Si o

I 5

s:

-s:

5

- I-5 s " s: k.

2 S ^

:>• c ; ; 10 S C

C3 s: o

10 c

eu C S

60 Ci

III X -Si 2

o ^ .a

go < s:

-Si 3

^ -5 §> ? S «>OJ: «-

5 .a

-s:

8

s: C c 3 c 5 ^ S -2 C ^ CO ^ ^ ^ 60 3 60 3 !i)

>z Vi C O V O O $ QQ U j ^ k l OQ ii,;

3

Si a N ? .b .2 o o ^ w a c

OQ - J Co T O OQ

Si .5 ?: "S I

C5

2 s

. 0

es

m f N

-O

a "5. o . es

es

eo _c "5. E es

ca

>v > ea

r o

O

•O >v

i 1 f N ii ^-^ Q. * - c/)

JZ ii 0 0 l -

C ^ (/) ii

- E

S >N

2 > c cs

~-^ ii 0 ^ "es r o

a ^

2 " " "B

1 ^ 3 cf

o _

es ii

I 1 g o

w> ^

U g

54

(

ing

'o. £ ed

T3 C ed

ing

lipp

CJ

O o

CO

.2 6 0) x: 13 <u

diff

eren

t fr

m

ent,

New

s ^ fO C3 ^ 0

ativ

e t

atio

na

"0 Z 00 u-

y ve

ie

lie

X) ^ ^ c: r g ^ Cd

£ m CO ^

"S s ed 0

% ^ ^

ensi

ty (

ha

bita

t st

ed^

mea

n d

atio

ns i

n PG

s c: T3 X

able

4.1

0.

A

eatm

ent

com

H i3

00

or:

r/.

0

cd 'So a c "§ B 2 S 0 ^

CJ

C 3 I T -, CJ

a 3 cr OJ 1 -

t x 60 c 'S, a

^ U

CJ

2;

H-l

S

K

ed (u H tJX

cd

vn r--uS 41^

r-->n

<

Z

^

OS

0

0?

O N 4j^

'NO IT)

^ ^ 0 0 d

CO

d 5,

<

z

Os 'd; 06

^

i n ^ -^ ^

'NO

od

-H

>n od

0^

X

Cd

m vq «n ^ ^

'd-

<

Z

0

d 41 00 rt-

CN

d 4^

O N

^ ^ ON

ed ^.^ CN

d

CN

<

^

m

od —— ^^^ >n -d-^.^ O N

od

'4^

f ^

od

ro

S

a

oT vq i n 4j^ 00 r t

<

z

t^ 00 C?N

4J^ 00 •d-

0

d

-d-

00 OS

+ "d-m

ed ..

•d-

d 5 0 •d-

<

z

so ro od —— ^ CN CN

^.^

i n od

4^

"d-ro

00 0 ON

ro VO

H J

ed

^ 0C5 W-i 4j^ CN)

"^

<

z

r^

Os

'd-

f N

ro CN

^.^ CN ro

d

vo m

ed ^ i i v

vo d

-d-

<

z

^

od —H

^ _ 00 •d-

"n vq od

ro ro

ro od

•d-

z

<

z

X cd

i n 4 ^ vo •d-

X

CNT ro i n 4^ OS ro ed

oT Os

4j_

vo i n

<

z

ed

oo"

OS

:il ro ro ed

CN? CN OS 41^

m

ed

00

ON 4j_ m 'd-

c (U 60

C -^

2 ^ 0

t/5 OJ

Vi

OJ

-0 ..-^ CTN O N O N

dJ

B a ii 43

1

OJ 1 -

cx k l

a G 3 0 CJ 0 ed Vi

c ed OJ

B

C/3

3 ^ ed

< >

u z < a

d" ed

^3 ii

cx ed Vi ed ^ 60

" & g ed is

X

ed OJ 1 -ed

'S 3 4J

C/3 OJ

.1 Si > ea OJ

X^

ro

0 <—" .. 4J

^-^ > ^

0 ed OJ

'oT ro C k. 0 0

sS -^ 3 '4_> — ed

> a 0 ^

^ 1 CX « ^

k- ' ^

00 60

S 0 C '^ ed *-

to ' iT

2 0

J B 'a = Cl- -K ^ § td _ .

^ 0 60 - ^ C k,

•a ° U "1

* i n

kH* 0

OJ kd

OJ

X 0 0 • -4J

3 t/3 OJ C/5

ed

2 X ed

JS 0 Cu

"ed

B 0

ci; 7 3 OJ

ii ii kH

Vi *-> •5 3

T3 60

1

3 0

z u

d d II ed

a, "ed .4->

ea C aj kH

^

•o ^ *ed 0

'•^.^ Vi

ed .4—» e/}

. 4 . ^

0 3 OJ kH Cd kH ii *-» a ^ B Vi

ii X X

'i 3 ii

B ca ii

3 X

' ^ Vi 3 ea OJ

£ •T3 3 ea kH

0 •0

55

(

.£ Id -

o •'" o

ing

mpl

Cd u H

Hig

h

mpl

i T

ra

Low

H

0£ a a £ es H

CQ U Oi

Mod

1;

OD

plin

S

No

T

t •

o ' ^

u^ m

o m

IT) n

• o n

•

m ^-H

1 O ^ H

tn

(U ed (L>

o

ed

ed CO

ed ^ CO

00 ^

£ r 00 CX o

.£ .&c2 o o

(J

a S

0£

*N es a

I d x'B CX ^ CX o

O C3 CO W

(D O

a* S (U ^ -

r l - Cd

s.i I-I ed

rS XH

^ s CQ

O

.> -4-> _ o O OJ -a CX ed CO

"O v-i <l)

IS w CX ja ed . ^ CO ^ ^

op g .£ -

<D

> o o

o o o S 00

^ £

1 ^ CO

^ (D

•^ o

« ><

CX

^ o

o ^ 1-1 •<-> o 00 ^

•^ 00

CO C

It o

O w

(o/ ) jaA03 J3wn

56

00 c iddi

o C M O

D CO (U

• ^ u

freq

ue

exic

o.

IS

liffe

n N

ew

'T3

c2 o (D £

jtativ

e ty

p na

l Mon

u yv

ege

Nat

io

"C "'5 £ -a

cove

r 00

)-

~ o .2 w 2 Id

led

mea

ns i

n M

C h

abit

nsfo

m

tions

i rc

sine

tra

com

bina

i

c 4> £ 52 Id

VE7> »-i ' O •*—• < 00

. .—H

.le4

.11

tram

pl

H ed

SES

00

Cx O

FOR

BS

S ^—V

fli 2P

• ^ C X

Gra

nd

(tra

m

>^

uenc

re

q

PH

00 c: C l

Clip

t>

:z;

J

S

ffi

§ 'oo t c: o

Tra

mp

Freq

u(

CO

0.1

OS

0.1

r-^

d

CN

d

r—4

- ^

d

CO

o

0.2

0.15

.2

7

o

.19

.20

0

o

X

CO

Oi

0.1

OS

0.1

r-^

d

c^ CN

d

0 0

d

CO

cx>

0.1

0.17

.2

3

o

.21

.13

0

o

S

CO

Oi

0.1

- ^

0.2

o CN

d

wo ^

d

d

CD

O

0.2

0.22

.1

8

o

.22

.17

0

o

H4

ed O

0.2

^

0.3

" ^ '-*,

o

Os ^

d

d

ed

0 0

0.1

0.19

.2

5

o

1.12

o

0 0

d

Z

X

0.23

cd

t^~

d

-S o CN

d cd

u-

d

ed

0.18

cd

CN

d

18a

17 a

0.

d

c ed ^-v u 00 S .£

Gra

nd

(gra

z

ates

. £

er e

sti

folia

r co

v 99

9)

y~^

tent

( e-

trea

m

rpr

unt

fo

cans

acc

o

£ T 3

- 4 — >

Vi

'5* ed <

NC

OV

<

a 'x

it ar

ea

c p

imes

p

"•-*

^

heav

;

ro

O

)der

ate)

.

CJ

CN C N

(lig

h (n

on

o

oval

' ro

p re

m

o 0 0

;tand

ir]

at 1

00%

s

-a

CX

Vi

ed ^

lipp

ing

vely

.

o 0)

co

times

, re

i

>» uS

erat

e),

or 3

(h(

2nt a

t al

pha

=

o .<u ^ (4H £ ^ ^ *'3

light

)

stic

al

',1(

st

ati

none

)

eno

t

^ ^ I H

^£ S

0 fo

otfa

lls/

the

sam

e le

, orl

O

)wit

h

d at

0,

5, 2

5

n tr

eatm

ent]

a 'x ' ^ * ! cd CO " 2

^ £ ^ s

tram

plin

g

^ G

rand

m

57

CO ed

S

ling

a E h< H

eavy

S

a S cs La

H 4> CQ

Ode

r

'^

D£ fi

2 OD

a fi

H «

.2f o

ItH

& •

00

c CX

<t> L ;

ed O <L) CJ

is •;< 00 «

.£ S £ ^

o o . (L> >

00

CX

c £ c o

o CO

ed

o ed

a c Z H 3 IH

ou W -H

M g ed „ CQ

— : ;H o •— ^ o U o o ^ CN ^ op c c: o -C CX CX

V-I .-H CO

• • ^ l-H

CO O

1 -O

I I 00 ^

sapads #

fN

I-I O

CN o

»n CO

-^ CO td w 73 £ 'H, S^ CX > ed ed CO ^ ed ^

00 i>

.£ i 4 - — - « - *

CX IH

£ ° u ed

- i ed o

IH ^

2 ^

•'-' S T3 O c: ed

CO CO

C O X o

• ^ ^

CX • -

00 £ ;-^ O PH U

CO

O O

I-I

o

c o

o (D N

^ ed u

I

o I-I ed

O C

^ 1o <U , e d

a, o B" c2 ed M H

58

ed OH

ON

0\

II

f S —\—

o

>» u a s cr Qi U b OD a *5,

Q.

Cli

men

i 2.

44,

runi

C „ <L> c3 II CX 0 < m CO X o (t)

pq o g ^ Px • -"ed ^ ^ < ^ • ^ D >%

habi

tw

ic

heav

U ^ ^ ^ O CO

.£ g °. >. o ^ " "O -s c: r~^

•4-J <i) •r:' —H CO > ed C3 •*= > o o o CX 3 C CO T3 C w o 2 ^ Vi ' - ' c CX a-

•— ^ o ^—\ 0) hj

£ o 2P »r) -is c: <N -O '-S o JS c: ^ ' S -^ ^ W CO

•ti a ^ > Id o

•z: o o O - ^ ^ H ^ CX * -' O CX « O ed ^ CX 00 <u

rim

ary

clip

pin

as a

ppli

xi- ro ^

§ 2 Op

Me

cted

ip

pin

5f " (U CO ^ v

El * - CN ed Op •=: o u

00 vo f S O ed

(j"iSZ0/3) jqSpAV ^JQ

59

Table 4.12. Mean densities (# plantsW ± s.e.) inside versus outside exclosures (1999 2000) - Bandelier National Monument, New Mexico.

Exclosure*

MCI

MC2

MC3

MC4

MC5

PG2

PG3

PG4

PJl

PJ2

PJ3

PJ4

PJ5

Treatment

inside

outside

inside

outside

inside

outside

inside

outside

inside

outside

inside

outside

inside

outside

inside

outside

inside

outside

inside

outside

inside

outside

inside

outside

inside

outside

Mean Density (1999)

108 ±17

208 ± 14

466 ± 32.5

262 ± 8.5

310 ±50.5

294 ± 0.5

1092 ±141

838 ± 60.5

274 ± 0.5

334 ±32.5

114±65

38 ±0

155 ±25.5

156.5 ±11.5

115±10

68 ±11

38 ±12

29.5 ±5.5

51.5 ±0.5

17.5 ±5.5

50.5 ±11.5

17.5 ±0.5

92.5 ±41.5

86 ± 9

28.5 ±18.5

30.5 ± 4.5

Mean Density (2000)

136 ±13

376 ±14

466 ±21.5

348 ±17

272 ±1

242 ± 4.5

1090 ±127.5

634 ±11.5

452 ± 46

274 ±25.5

69.5 ± 35.5

66.5 ± 4.5

18±12

127.5 ±5.5

86.5 ±18.5

93 ±11

36.5 ± 15.5

40.5 ± 8.5

53.5 ±1.5

20 ± 2

76.5 ± 11.5

30.5 ±1.5

53 ±18

60.5 ±12.5

35.5 ± 13.5

42 ± 8

Because MC sites were sampled on a 0.25m2 area, densities are multiplied by a factor of 4.

60

Table 4.13. Mean fohar cover (%/m ± s.e.) inside versus outside exclosures (1999 -2000) - Bandelier National Monument, New Mexico.

Exclosure*

MCI

MC2

MC3

MC4

MC5

PG2

PG3

PG4

PJl

PJ2

PJ3

PJ4

PJ5

Treatment

inside

outside

inside

outside

inside

outside

inside

outside

inside

outside

inside

outside

inside

outside

inside

outside

inside

outside

inside

outside

inside

outside

inside

outside

inside

outside

Mean Foliar Cover (1999)

6.202 ± 0.35

3.02 ± 0.003

14.81 ±1.80

4.002 ± 0.55

2.804 ± 0.00

5.708 ±0.12

9.202 ± 0.95

14.612 ±0.75

4.716 ±0.13

8.916 ±0.13

8.155 ±1.35

8.695 ± 0.79

2.016 ±1.30

8.5295 ± 2.27

10.025 ±0.95

4.9605 ± 0.71

8.085 ±0.12

6.3 ±3.9

8.8 ± 0.00

7.975 ±4.88

9.575 ± 0.52

7.785 ±1.39

7.175 ± 1.66

4.475 ± 0.45

4.465 ± 3.32

5.63 ± 0.78

Mean Foliar Cover (2000)

8.018 ±0.40

5.726 ± 0.43

15.21 ±0.05

6.61 ± 0.50

6.712 ±0.48

6.01 ± 0.20

28.61 ±5.05

14.416 ±0.001

6.42 ± 0.75

8.118 ±0.52

24.378 ±13.68

24.93 ± 3.03

5.154 ±0.72

11.1335±1.13

21.680 ±3.57

8.8545 ±1.20

16.35 ±3.75

17.201 ±8.80

11.878 ±3.47

11.252 ±0.75

17.976 ±2.38

17.1755 ±3.22

9.177 ±0.98

9.0755 ± 0.77

7.0255 ± 2.92

9.577 ±0.77

Because MC sites were sampled on a 0.25m2 area, % cover is multiplied by a factor of 4.

61

Table 4.14. Mean litter cover (%W ± s.e.) inside versus outside exclosures (1999 2000) - Bandelier National Monument, New Mexico.

Exclosure Treatment Litter Cover (2000)

MCI inside 92 ±1.0

outside 88 ±1.0

MC2 inside 64 ± 6.0

outside 56 ± 8.0

MC3 inside 44 ±5.0

outside 91 ± 1.75


outside 24 ±1.0


outside 69 ± 4.75

PG2 inside 18.875 ±2.38

outside 28.625 ± 10.88

PG3 inside 38.75 ± 19.25

outside 25 ±1.5

PG4 inside 12.2 ±2.55

outside 15.5 ±3.5

PJl inside 11.8 ±5.9

outside 4.2 ± 0.7

PJ2 inside 11.75 ±7.25

outside 1.8505 ±0.55

PJ3 inside 8.5 ±1.3

outside 11.875 ±0.38

PJ4 inside 3.8255 ±1.92

outside 5.625 ± 1.63

PJ5 inside 7.4 ±0.55

outside 4.075 ± 0.78

Because MC sites were sampled on a 0.25m2 area, % litter is multiplied by a factor of 4.

62

CHAPTER V

DISCUSSION AND MANAGEMENT IMPLICATIONS

During the course of this study, BAND experienced two unseasonably warm

years. Plant communities are influenced as much, if not more, by abiotic variables (e.g.,

inter-annual differences in growing season precipitation) than by ungulate populations

(Peterson et al. 1997). Winkel and Roundy (1991) found seedling emergence in response

to cattle trampling differed among years and treatments relative to precipitation pattems

and periods of available water. Olson et al. (1985) indicated that each species reacts to

precipitation regimes and grazing pressure in a unique manner. Control of vegetation

dynamics by precipitation is much more likely in arid and semiarid regions (Petersen et

al. 1997). Grazing and concomitant trampling can directly push these regions across soil

erosion thresholds by concurrently reducing intercanopy vegetation cover and soil water

infiltration capacities (Davenport et al. 1998).

Though foliar cover and density data were analyzed across as well as within

habitats, the within habitat analyses are probably more meaningftil. Given the

migrational behavior of elk, elevational partitioning occurs in different seasons resuhing

in heavier use of certain habitats during some parts of the year. Impacts caused by

clipping and/or trampling may also be confounded when looking at individual plant

species or differing precipitation regimes (Olson et al. 1985, Cole 1995, Cole 1998) - all

of which vary from one elevational zone to another. This may be somewhat illustrated

by the significant habitat X trampling interaction we detected for total foliar cover.

Moderately trampled units in ponderosa habitats had 2.5 times more foliar cover than in

63

PJ, and nearly 4 times more than in MC sites. However, within habitat analysis in PG did

not reveal any trampling effects on foliar cover.

Plant densities were higher in heavily clipped plots in PJ habitat versus

moderately or non-clipped experimental units. It is possible that bunchgrasses in PJ sites

responded to heavy clipping pressure coupled with above average seasonal temperatures

and lower moisture with a breakup of the original plants which were then counted as

more individual plants the following year. Trampling applied to those plots exacerbated

this effect by pulverizing the dead or dying connective portions of bunchgrasses.

However, the dominant species in this habitat type was blue grama which is deemed to be

tolerant of grazing and trampling {Fire Effects Information System 1996).

Grass densities in PG habitat followed this same trend in response to clipping

frequency with heavily clipped sites having a higher density than moderately clipped

areas. Intensity of clipping did not have any detectable effect on overall plant densities in

PG habitat; however, clipping appeared to interact with trampling intensity in MC sites.

Moderately grazed and trampled units tended to have relatively higher grass cover than

any other treatment combination in these sites. A clear explanation for this is not

available, although other studies have advocated the use of grazing or trampling to

stimulate forage production (Savory and Parsons 1980, McNaughton et al. 1983).

Though not supported by results in other habitats, it is possible that moderate levels of

clipping and trampling complement each other providing optimum growing conditions

for grasses in MC habitats in this region.

One result that appeared to be consistent regardless of habitat was the effect of

clipping intensity on total litter cover. Significantly less litter cover was found in heavily

64

clipped plots in PJ and MC exclosures. A negative correlation of grazing intensity to

litter cover has been documented elsewhere (Biondini et al. 1998). This trend was also

apparent with clipping frequencies in PG, but not in PJ or MC habitats.

Measures of basal area did not change with this first year's treatments. Species

richness was only affected by treatments in MC sites where heavy intensities of trampling

or a combination of the extreme frequencies (i.e., 0 or 3 times) of clipping or trampling

coupled with moderate levels of the opposite treatment resulted in fewer species. Such

inconsistencies or lack of response can be explained in two ways. First, only a single

year has elapsed between initial treatment applications and the resultant data collection

reported here. Much longer time periods - periods in the range of 20 years - may be

needed to detect vegetative responses to changes in grazing pressure (Chong 1992)

especially in ecosystems that have developed with a history of grazing pressure. Short

duration studies are seldom sufficient to isolate the effects of treatment from short-term

climatic responses. Secondly, all vegetative parameters I measured had high intrinsic

variability. Though trends may be developing (as in the case of trampling), this

variability probably conceals most treatment effects. For instance, changes in basal cover

for individual plant species may be highly susceptible to precipitation (Olson et al. 1985)

indicating that dominant species and their response to precipitation fluctuation need to be

identified over the long-term/?nor to evaluating grazing/trampling effects.

At the lower elevations blue grama increased with a subsequent decrease in

mountain muhly. Blue grama is known to be tolerant of grazing (Santos and Trlica 1978,

Bock and Bock 1986) and may even increase in overgrazed range {Fire Effects

Information System 1996). In contrast, an Arizona study using long-term exclosures

65

indicated that mountain muhly showed the greatest increase in ungrazed quadrats,

occurred in "patches" when moderately grazed, and disappeared when overgrazed

(Arnold 1950). Similarly, in Colorado cover increased as grazing decreased (Johnson

1956) comprising 20% of the composition in ponderosa habitat on heavily grazed areas

compared to 45% on those not grazed. Results of our "intensity" study support these

pattems. However, the opposite effect was seen with regard to trampling frequency; blue

grama decreased with increasing trampling frequency whereas mountain muhly

increased.

Seasonal progression of environmental variables and phenological development

of individual plants may confound effects of defoliation frequency and intensity (Briske

and Richards 1995). Climate may confound interpretation since blue grama is more

commonly known to be drought-tolerant (U.S. Department of Agriculture 1940, Menke

and Trlica 1981, Fire Effects Information System 1996) - a condition which appears to be

prevalent the last couple of years in this region of the Jemez Mountains. Boryslawski and

Bentley (1985) reported a significant interaction between temperature regime and

clipping treatment with blue grama being less sensitive to clipping at higher temperatures

than Westem wheatgrass.

At mid-elevational ponderosa grassland sites, broom snakeweed and Westem

wheatgrass exhibited compositional shifts. Snakeweed, which was also found in PJ sites,

is an aggressive invader occupying sites where climax vegetation has depleted because of

fire, grazing, or drought (U.S. Department of Agriculture 1940), but is useless as forage.

Westem wheatgrass is also drought- and grazing-tolerant and is good winter forage for

elk and deer (U.S. Department of Agriculture 1940), but it is known to be less tolerant to

66

clipping at higher temperatures than blue grama (Boryslawski and Bentley 1985). Our

results do not support this observation since we observed an increase in composition of

wheatgrass at the highest frequencies of clipping and trampling and at moderate

intensities of trampling alone.

Other notable shifts in species composition in PG included a decrease in

goosefoot spp. numbers and an increase in trailing fleabane. Trailing fleabane is

relatively poor forage because of its ground-level growth form and is generally classified

as an increaser on grazed lands (U.S. Department of Agriculture 1940). The

disappearance of goosefoot spp. in our sites cannot be explained because of a lack of

information on responses to grazing and trampling in the literature. However, treatments

were applied at the earliest part of the growing season when these plants were seedlings

and were probably unable to tolerate such extreme conditions.

Arizona three-awn decreased in relative composition when heavy clipping or

trampling was applied, but increased on non-treated units and inside versus outside

exclosures. Little information exists in the literature regarding response to grazing

pressure, but it is generally thought to have poor forage value because of its prominent

awns (U.S. Department of Agriculture 1940).

In mixed conifer regions, noticeable shifts in relative composition occurred with

white-clover, bluegrasses, sedges, and pussytoes. White clover is considered excellent

forage for ungulates {Fire Effects Information System 1996) and withstands trampling

well (U.S. Department of Agriculture 1940), but it is not tolerant of drought conditions

(Gibson and Cope 1985). Our results support this observation with the greatest relative

increases in white clover occurring at the heaviest intensity of trampling and at low

67

frequencies of trampling. Though not evident with this study, plants can adapt to severe

defoliation by developing smaller leaves and more stolons (Ryle et al. 1989) and it has

been reported that this plant may grow stronger and bulkier (i.e., become more robust)

when grazed (U.S. Department of Agriculture 1940, Chapman et al. 1992, Hay et al.

1989). In addition, white clover is a species with a high degree of phenotypic plasticity

which can result in large fluctuations in size of individual plants (Hay et al. 1989).

Individual species of Carex, Poa, and Antennaria respond to grazing pressures

and climate differently (U.S. Department of Agriculture 1940) making it difficult to

interpret our results which are based on generic classifications. In general, Poa spp. are

known to be good to excellent forage and resistant to heavy trampling, grazing, and

drought conditions (U.S. Department of Agriculture 1940, Stubbendieck et al. 1985)

because growing points are belowground throughout the growing season for most species

(Ehrenreich et al. 1963). Poa spp. increased with increasing clipping intensity in our

study, but decreased as clipping frequency increased. Contradictorily, this genera also

increased when grazers were excluded through the use of exclosures. Intermediate

intensities of clipping and trampling increased the relative contribution oi Carex in our

study and it did not appear to benefit when protected from grazers. Antennaria spp.

increased with clipping intensity, but also appeared to increase when protected from

grazing (i.e., inside exclosures). One species, A. parvifolia, has been shown to decrease

slightly under light to moderate grazing, but increase in heavily grazed areas (Smith

1967). In ponderosa communities, it has been shown to survive heavy trampling (Smith

1967). Again, conflicts in our results are probably indicative of climatic and phenotypic

variability during the course of this study. In addition, the unseasonably warm weather

68

resulted in elk remaining at higher elevations. Therefore, the unfenced reference areas

did not receive the level of impact they normally would if elk were in the area. This

made interpretation of results inside versus outside exclosures difficult.

Trampling, in general, more consistently impacted parameters measured though

results were not statistically significant in all cases. In fact, in many of the ANOVAs and

ANCOVAs we ran, trampling effects showed the most significant response (i.e.,

approached a = 0.10) when compared to either clipping or trampling X clipping effects.

Specific responses to trampling were difficult to interpret. In PJ communities,

moderately trampled plots had less total foliar cover than lightly trampled units in our

"intensity" study. Further inspection indicated that lightly trampled treatments had

significantly higher forb cover in this community. In contrast, moderately trampled units

had a higher density of plants than non-trampled areas in PG, but densities were not

different from lightly or heavily trampled sites. Finally, MC sites had significantly more

species in lightly trampled locations compared to heavily treated areas, but not when

compared to moderately or non-trampled quadrats. In total, these observations suggest

that there may be an intermediate threshold at which trampling may stimulate plant

productivity, especially in terms of forb response.

Similar responses to trampling have been reported in the literature. Cole and

Spildie (1998) concluded forb-dominated sites were highly vulnerable to trampling

effects, but recovered rapidly. The ability of a vegetation type to tolerate recurrent

trampling disturbance may be more a function to recover from damage than its ability to

resist being damaged (Cole 1995). Cole (1995) ftirther stated that certain vegetation

types might exhibit thresholds of vulnerability in response to trampling that, when

69

exceeded, may result in even greater damage to the plant. Guthery and Bingham (1996)

developed a theoretical basis to predict the probability of domestic trampling loss,

influence of underlying assumptions, and development of altemative models for dealing

with nonrandom grazing which may be enlightening to the land manager.

There are three main explanations for the variable and inconsistent results we

found in this study. First, there may be a possibility that heavy winter and variable spring

grazing, with associated trampling, may not cause extensive plant mortality or

progressive changes in basal area (Houston 1982), especially during dormant phases of

plant life cycles. As was previously mentioned, much longer time periods - periods in

the range of 20 years - may be needed to detect vegetative responses to changes in

grazing pressure (Chong 1992) especially in ecosystems that have developed with a

history of grazing pressure. Finally, initial variability of pre-treatment data was

indicative of the amount of inherent variability present in the vegetative communities of

BAND. Standard error values for all parameters (see appendices) vacillated to the extent

that potential significant effects could be concealed by variability. These factors,

coupled with climatic variables, make interpretation of results volatile with only a single

year of post-treatment data.

70

LITERATURE CITED

Abdel-Magid, A. H., M. J. Trlica, and R. H. Hart. 1987. Soil and vegetation responses to simulated trampling. Joumal of Range Management 40(4):303-306.

Allen, C. D. 1996. Elk response to the La Mesa Fire and current status in the Jemez Mountains. Pages 179-195 in C. D. Allen, technical editor. Fire effects in Southwestem forests: Proceedings of the second La Mesa Fire symposium. RM-GTR-286. USDA Forest Service Rocky Mountain Forest and Range Experiment Station, Fort Collins, Colorado.

Amold, Joseph F. 1950. Changes in ponderosa pine bunchgrass ranges in northem Arizona resulting from pine regeneration and grazing. Joumal of Forestry. Febmary: 118-126.

Balph, D. F. and J. C. Malecheck. 1985. Cattle trampling of crested wheatgrass under short-duration grazing. Joumal of Range Management 38(3):226-227.

Bastrenta, B., J. Lebreton, and J. D. Thompson. 1995. Predicting demographic change in response to herbivory: a model of the effects of grazing and annual variation on the population dynamics of Anthyllis vulneraria. Joumal of Applied Ecology 83:603-611.

Biondini, M. E., B. D. Patton, and P. E. Nyren. 1998. Grazing intensity and ecosystem processes in a northem mixed-grass prairie, USA. Ecological Applications 8(2):469-479.

Bock, Jane H., and Carl E. Bock. 1986. Habitat relationships of some native perennial grasses in southeastem Arizona. Desert Plants. 8(1): 3-14.

Boryslawski, Z, and B. L. Bentley. 1985. The effect of nitrogen and clipping on interference between C3 and C4 grasses. Joumal of Ecology 73:113-121.

Brand, M. D., and H. Goetz. 1986. Vegetation of exclosures in southwestem North Dakota. Joumal of Range Management 39(5):434-437.

Briske, D. D., and J. H. Richards. 1995. Plant responses to defoliation: a physiological, morphological and demographic evaluation. Pages 635-710 in Wildland Plants: Physiological ecology and developmental morphology. D. J. Bedunah and R. E. Sosebee, eds. Society for Range Management.

Brown, D. 1954. Methods of surveying and measuring vegetation. Commonwealth Agricultural Bureaux, Famham Royal, Bucks, England. 223 pp.

71

Buono, F. 1997. Managing wildlife in the parks: the legal basis. The George Wright Fomm. 14(1): 18-24.

Campa, H., J. B. Haufler, and D. E. Beyer, Jr. 1992. Effects of simulated ungulate browsing on aspen characteristics and nutritional qualities. Joumal of Wildlife Management 56(1): 158-164.

Chapman, D. F., M. J. Robson, and R. W. Snaydon. 1992. Interactions between defoliation and the nitrogen nutrition of white clover {Trifolium repens L.): Effects on carbon utilisation in clonal plants. Plant and Soil 139:157-165.

Chong, G. W. 1992. Seventeen years of grazer exclusion on 3 sites in pinyon-juniper woodland at Bandelier National Monument, New Mexico. BAND Park Report.

Cole, D. N. 1995. Experimental trampling of vegetation. I. Relationship between trampling intensity and vegetation response. Joumal of Applied Ecology 32:203-214.

.1995. Experimental trampling of vegetation. II. Predictors of resistance and resilience. Joumal of Applied Ecology 32:215-224.

Cole, D. N. 1988. Disturbance and recovery of trampled montane grassland and forests in Montana. USDA Forest Service Intermountain Resource Station, Ogden, Utah.

Cole, D. N., and D. R. Spildie. 1998. Hiker, horse and llama trampling effects on native vegetation in Montana, USA. Joumal of Environmental Management 53:61-71.

Conley, W., R. Sivinski, and G. White. 1979. Responses of elk (Cervus elaphus) and mule deer (Odocoileus hemionus) to wildfire: changes in utilization and migration pattems. Final Report for Bandelier National Monument. Contract No. CX7029-7-0057. 88 pp.

Croft, A. R., and L. Ellison. 1960. Watershed and range conditions on Big Game Ridge and vicinity, Teton National Forest, Wyoming. USDA Forest Service, Ogden, UT. 37 pp.

Daubenmire, R. F. 1959. A canopy-coverage method of vegetation analysis. Northwest Science. 33:43-54

Davenport, D. W., B. P. Wilcox, and D. D. Breshears. 1996. Soil morphology of canopy and intercanopy sites in piilon-juniper woodland. Soil Science Society of America Joumal 60:1881 -1887.

72

Davenport, D. W., D. D. Breshears, B. P. Wilcox, and C. D. Allen. 1998. Viewpoint: Sustainability of pinyon-juniper ecosystems - a unifying perspective of soil erosion thresholds. Joumal of Range Management 51:231-240.

Demer, J. D., R. L. Gillen, F. T. McCollum, and K. W. Tate. 1994. Little bluestem tiller defoliation pattems under continuous and rotational grazing. Joumal of Range Management 47(3):220-225.

Despain, D. G. 1989. Interpretation of exclosures in riparian vegetation. Page 188/« Practical approaches to riparian resource management: an educational workshop. 1989. Billings, Montana.

Ehrenreich, John H., and J. M. Aikman. 1963. An ecological study of the effect on certain management practices on native prairie in Iowa. Ecological Monographs. 33(2): 113-130.

Fettig, S., editor. 1997. Environmental assessment of proposed evaluation of ungulate impacts to park resources: a research project using exclosures. Unpublished environmental assessment on file at Bandelier National Monument. USDA National Park Service, Bandelier National Monument, Los Alamos, New Mexico. 46 pp.

Fire Effects Information System [Online] (1996, September). Prescribed Fire and Fire Effects Research Work Unit, Rocky Mountain Research Station (producer). Available: ^^^^v^.is.iQdi.uslddXdbdiSdFire Effects Information System! [1998, March 12]

Foxx, T. S. 1984. La Mesa Fire Symposium. Pages 1-10 /« Foxx, T. S., editor. La Mesa Fire Symposium. LA-9326-NERP. Los Alamos National Laboratory, New Mexico. U.S. Govemment Printing Office.

Gaffney, W. S. 1941. The effects of winter elk browsing, south fork of the Flathead River, Montana. Joumal of Wildlife Management 5(4):427-453.

Gibson, P. B., and W. A. Cope. 1985. White clover. In: Clover science and technology. Agronomy Monograph No. 25. Madison, WI: Soil Science Society of America. 25:471-490.

Gillen, R. L., F. T. McCollum, and J. E. Bmmmer. 1990. Tiller defoliation pattems under short duration grazing in tallgrass prairie. Joumal of Range Management 43(2):95-99.

Gmell, G. E. 1973. An ecological evaluation of Big Game Ridge. USDA Forest Service Intermountain Region, Teton National Forest, WY. 62 pp.

73

Guthery, F. S., and R. L. Bingham. 1996. A theoretical basis for study and management of trampling by cattle. Joumal of Range Management 49:264-269.

Hay, M. J. M., J. L. Brock, and V. J. Thomas. 1989. Density of Trifolium repens plants in mixed swards under intensive grazing by sheep. Joumal of Agricultural Science (113):81-86.

Hoskins, L. W., and P. D. Dalke. 1955. Winter browse on the Pocatello Big Game Range in Southeastem Idaho. Joumal of Wildlife Management 19(2):215-225.

Houston, D.B. 1982. The Northem Yellowstone Elk. MacMillan Publishing Co., Inc. New York, NY. 474 pp.

Johnson, W. M. 1956. The effect of grazing intensity on plant composition, vigor, and growth of pine-bunchgrass ranges in central Colorado. Ecology 37(4): 790-798.

Kay, C. E. 1994. The impact of native ungulates and beaver on riparian communities in the intermountain west. Natural Resources and Environmental Issues 1:24-44.

Kay, C. E. 1995. Browsing by native ungulates: effects on shmb and seed production in the Greater Yellowstone Ecosystem. Pages 310-320 in Roundy, B. A., E. D. McArthur, J. S. Haley, D. K. Mann, compilers. 1995. Proceedings: wildland shmb and arid land restoration symposium; 1993 October 19-21, Las Vegas, Nevada. General Technical Report INT-GTR-315. USDA Department of Agriculture, Forest Service, Intermountain Research Station, Ogden, Utah.

Kay, C. E. 1997. Yellowstone: ecological malpractice. PERC Reports 15(2): 1-39.

Leopold, A. S., S. A. Cain, C. M. Cottam, I. N. Gabrielson, and T. L. Kimball. 1963. Wildlife management in the national parks. Transactions of the North American Wildlife Resource Conference 28:28-45.

Lissoway, J. D. 1996. Elk response to the La Mesa Fire and current status in the Jemez Mountains. Pages 7-10 in C. D. Allen (tech. ed.). Fire effects in Southwestem forests: Proceedings of the second La Mesa Fire symposium. USDA Forest Service Rocky Mountain Forest and Range Experiment Station, Fort Collins, Colorado.

McCorquodale, Scott M., Aberheardt, L. L. Aberheardt, L. E. Aberheardt. 1988. Dynamics of a colonizing elk population. Joumal of Wildlife Management 52:309-313

McCulloch, Jr., C. Y. 1955. Utilization of winter browse on wildemess big game range. Joumal of Wildlife Management 19(2):206-214.

74

McNaughton, S. J., L. L. Wallace, and M. B. Coughenour. 1983. Plant adaptation in an ecosystem context: effects of defoliation, nitrogen, and water on growth of an African sedge. Ecology 64(2):307-318.

Menke, J. W., and M. J. Trlica. Carbohydrate reserve, phenology, and growth cycles of none Colorado range species. Joumal of Range Management 34(4):269-277.

Motazedian, I. J., and S. H. Sharrow. 1990. Defoliation frequency and intensity effects on pasture forage quality. Joumal of Range Management 43(3): 198-201.

New Mexico Department of Game and Fish (NMGF). 1997. The long-range plan for the management of New Mexico's elk. Unpublished Report - Febmary 1997. 24 pp.

Oesterheld, M. 1992. Effect of defoliation intensity on aboveground and belowground relative growth rates. Oecologia 92:313-316.

Olson, B. E., and J. H. Richards. 1988. Spatial arrangement of tiller replacement in Agropyron desertorum following grazing. Oecologia 76:7-10.

Olson, K. C , R. S. White, and B. W. Sindelar. 1985. Response of vegetation of the northem Great Plains to precipitation amount and grazing intensity. Joumal of Range Management 38(4):357-361.

Parker, K. 1997. LANL using high-tech trapping to save elk herd. Santa Fe New Mexican, 15 August 1997.

Peterson, J., J. Fahnestock, and J. K. Detling. 1997. Ungulate/vegetation interactions at the Pryor Mountain Wild Horse Range. Bureau of Land Management Report, Cooperative Agreement Number 1268-1-9002. Department of Biology, Colorado State University, Ft. Collins, CO. 154 pp.

Ralphs, M. H., M. M. Kothmann, and C. A. Taylor, 1990. Vegetation response to increased stocking rates in short-duration grazing. Joumal of Range Management 43(2): 104-108.

Ryle, G. J. A., C. E. Powell, M. K. Timbrell, and J. P. Jackson. 1989. Carbon and nitrogen yield, and N2 fixation in white clover plants receiving simulated continuous defoliation in controlled environments. Annals of Botany 63:675-686.

Santos, Glenio L., and M. J. Trlica. 1978. Clipping effects on production and carbohydrate reserves of blue grama and westem wheatgrass. In: Hyder, Donald N., ed. Proceedings of the 1st Intemational Rangeland Congress; 1978 August 14-18; Denver, CO. Denver, CO: Society for Range Management: 384-386.

75

Savory, A., and S. D. Parsons. 1980. The Savory grazing method. Rangelands 2:234-237.

Shmida, A. Whittaker's plant diversity sampling method. Israel Joumal of Botany 33:41-46.

Smith, Dwight R. 1967. Effects of cattle grazing on a ponderosa pine-bunchgrass range in Colorado. Technical Bulletin No. 1371. Washington, DC: U.S. Department of Agriculture, Forest Service. 60 p.

Sokal, R. R., and F. J. Rohlf 1995. Biometry: the principles and practice of statistics in biological research (3'"' edition). W. H. Freeman and Company, New York, N.Y. 887 pp.

Steel, R. G. D., and J. H. Torrie. 1980. The randomized complete block design: more than one observation per treatment per block. Pages 215-218 in Principles and procedures of statistics: A biometrical approach (2"' ed.). McGraw-Hill, Inc. New York, NY.

Stubbendieck, J., J. T. Nichols, and K. K. Roberts. 1985. Nebraska range and pasture grasses (including grass-like plants). E.C. 85-170. Lincoln, NE: University of Nebraska, Department of Agriculture, Cooperative Extension Service. 75 p.

Sun, D., and M. J. Liddle. 1991. Field occurrence, recovery, and simulated trampling resistance and recovery of two grasses. Biological Conservation 57:187-203.

Telfer, E. S. and J. P. Kelsall. 1984. Adaptation of some large North American mammals for survival in snow. Ecology 65(6): 1828-1834.

Tollner, E. W., G. V. Calvert, and G. Langdale. 1990. Animal trampling effects on soil physical properties of two Southeastem U.S. utisols. Agriculture, Ecosystems, and Environment 33:75-87.

Tucker, T., and W. C. Leininger. 1990. Differences in riparian vegetation stmcture between grazed areas and exclosures. Joumal of Range Management 43(4):295-299.

U.S. Department of Agriculture (USDA), Forest Service. 1937. Range plant handbook. Washington, DC. 532 p.

Warren, S. D., T. L. Thurow, W. H. Blackbum, and N. E. Garza. 1986. The influence of livestock trampling under intensive rotation grazing on soil hydrologic characteristics. Joumal of Range Management 39(6):491-495.

76

Weigel, J. R., C. M. Britton, and G. R. McPherson. 1990. Trampling effects from short-duration grazing on tobosagrass range. Joumal of Range Management 43(2):92-95.

Wilcox, B. P., and D. D. Breshears. 1994. Hydrology and ecology of pinon-juniper woodlands: conceptual framework. Pages 109-119 in D. W. Shaw, E. F. Aldon, and C. LoSapio, technical coordinators. 1995. Desired fixture conditions for pinon-juniper ecosystems. USDA Forest Service General Technical Report. RM-258. Rocky Mountain Forest and Range Experiment Station, Fort Collins, Colorado.

Wilcox, B. P., B. D. Newman, C. D. Allen, K. D. Reid, D. Brandes, J. Pitlick, and D. W. Davenport. 1996. Runoff and erosion on the Pajarito Plateau: observations from the field. Pages 433-439 in New Mexico Geological Society Guidebook: 47 * Field Conference, Jemez Mountains Region, 1996. New Mexico Geological Society Guidebook, Albuquerque, New Mexico.

Winkel, V. K., and B. A. Roundy. 1991. Effects of cattle trampling and mechanical seedbed preparation on grass seedling emergence. Joumal of Range Management 44(2): 176-180.

Wolters, G. L. 1996. Elk response to the La Mesa Fire and current status in the Jemez Mountains. Pages 196-205 in C. D. Allen, technical editor. Fire effects in Southwestem forests: Proceedings of the second La Mesa Fire symposium. RM-GTR-286. USDA Forest Service Rocky Mountain Forest and Range Experiment Station, Fort Collins, Colorado.

77

APPENDIX A

EXCLOSURE MAPS

78

u u z

ti b

ii

<r>

o tr

iur9i

Ii isod m9

nnnn nnnn nnnn nnn

nnnn nnnn nnnn nnn

jsod pj£

79

t I oa

i u

M b

nn DD nn nn nn nn nn •n

1 -3 2 3

^ i"2£ J.

a E o CJ

[ n

O

o IU801

• • • • • • • • • • • •

I ^ 1 * • • • • • • • •

u E o u

O u X

u o c ed kH c ii o

H

i

i CO Cd <o o o

(L» £^ Cd I

'E o u

V

ed CO

CO _ ^

O T3 H CJ o

O 00 "O 0 ) CO

CO Cd

o o

o c

CJ

o

c ii

ME a. X ii

Cd D 1) I—I "^

. 2 CJ ^

jj o jr" O l-i _

S * ti I H <L) :>

W ^ . £ S c>o

r^ a X

O H (D J 3

• u u c CO

ed a> I -ed u o C a> u

CJ ed OJ

<4H o

(4H

I d X

u eo o

ji< c

s

«

c ii a.

^

I H U

CO a> O X

-o H X . I-I D

a o O 'O

jcd .52 Zn Cd Cd ju

•4-> I - I

C ed C - «

.£ ^ fe « PJ is

ed CN X

< ^ D O

op-c •px O

o^

c CO

*£

£ o

M H

Cd 4—>

Cd

Q

c o CO u, 0) CX

Q < PQ >^

X —. " O •4—>

« 2 CJ T3 3 ed

'^ S-c cr o c CJ . —

80

25 m 00

24.5 m f n n n n I nnnn ^nnnn

nnnn u

.o E

0)

VtH o I-I

cs o -^ CJ CO

O CO CO iU

•o a> td H c 0 0 ^

•55 o 4) "O

o CJ

c o

u o

o OJ Cd OJ

7 3 1) fl^

£ ^ ^

.J^ t ( H ••

CJ - i ; * 3

CO 3 — •— CO C

1) J2 '5b CJ o « £ X -^

PJ rt *-

- • «.H <

c ^ O -

t a o c k-

•4.H c u o

H

tV,

o

ti

.9 .

nnnn^ nnnn / nnnn / nnnn/

nnnn nnnn nnnn nnnn

luei

•r>

E o u

gJSod

C/l O CX

c u

.i-E s = Q.

• u o c w C ii

u oo o

qj9 01 qjs

c

«

c o.

< l -

Ox Cd " X W fe cd • £ QJ O

S -fi Ul r "

C*H

U4 g j

QJ ^

c CO

4->

"£ £ o

Cd 4—•

ed

Q

w o «J

CO D

CJ CO X • -(u Cd k - <L)

Cd

ti -C 5 CJ O ed >% o Cd c*H

;^ o 15 ^ U X B i>

•fi c u o

U CO

P H U

OJ c c o CO

u

Z Cd

< -^

m 3 >^ or -o •—

O o X Cd o

(.ri CO

ed CJ

?? Cd kH CO

81

uig-gi

corr

^

^LOl W

E r-o

E

_ "^

nnnn nnnn nnnn nnnn

ti

u

ti ti ti

^n

;3

O

u X ti

0Q

• • • • • • • • • • • • • • •

• • • • '<•••• ' • • • • Lpnnn

oo so

I cs

O u

OJ J3

E o CJ

X 4—> 3 O CO

a> X

U 4—• ed o O^ Vi

OJ CJ

c cd I-I

4->

c

S = DH CL •* X u

o C

OJ

u O

• ed

Ul

cd

OJ CJ C OJ U4

2 ^

" u

DI Ul

_0 C4_|

4-> 3 O >% ed

c a o.

^

c 0)

OJ CX X

PJ

Ul 3 op

CO

4> u - ^ o cd

, 0 4-> C*H CO

"O «

td H c 0 0 ^ 3

"co « OJ "O " s 58 CJ

Cd i >

ed OJ Ul ed o CJ c OJ D 1—1

C*H ••

^ X " ^ 4—•

CJ • >

CO C

a *ob X X

• f i ^ CJ ^

«*H <

o -C4-I * -

Id a X CX

CJ c JC • -t i ^ o .ti u c

X 3

^ s 1 ) CtH

•T3 .2 13 ed C O C Cd CO

^ ^ « Q

^ § t*H < ,

Id ffl ^• -fi > . ^

< i i ed

tl i-6'S.s

O -o (D CJ (u

^ ^ td ^ " § O Cd ^ "5 " « X fl) u QJ u Cd

jsod qig

82

O U X ti

ii E o CJ

• • • ^<nnn_ |5 • • • • _pnnn

mZ. 01 qJ9

83

IU87.

^ir^r^ ti u z.

ti ti

E oo E o u

nnnn nnnn nnnn nnnn

ii E o o Z o H

ii

nnn nnnn nnnn nnnn

Q

O

u X ti

ii

CS

CO

u - ^ o Cd

, 0 4--C 4 - 1 C O

^ ^ X • ^ tJ XH 4-" ed " O 0 0 ^ u *co W U QJ - o

E - fe O CO o CJ Cd i j CO _ H_.

ed cd O C

c o o

CJ

o o

c u •i-E s = CL K

u ed

"^ )n H J fl) , D •—'

i : «*H -CO y JS CJ - ^ ^ o CJ • >

— u ^ CO 3 _

• — CO C « ^ "Ei) y CJ D £ X X5 2 Ci 4--

4-< -— Cd

c •fi .c PJ ^ *-CN 'ti < :0 CU

• u u c

D

Id ^ X CX

Cd u -CJ (U _ c

CO • £ CO CJ o .ti o u c ^ L - _ ^ r" c fl> C

yx . o u - a -u. u a j C4-1

u o 2 3 S- cd

cq fe'Q IJ CO —-•

oo o

X • -w Cd u W

. 0 ^

c c

cd CO

o CX

X

o 4-.*

X 4—

c 2

»

c ii a.

^

t i JS o 5 CJ CX O ed ^ >. o Q ed VKH • - 7

- ' ^ $

y ^ >, £ CJ • ^

• u fi "O O O O

• (U CJ

< fa ^ —^ C J

O CO ti fa O Jd

Px CJ U

ed u

•a ed 3 CT

-o CJ

4—' Cd CJ O^ QJ u cd

jsod pu^

84

I" 83

ti U Z

ti ti

a E o a

z o

i

CJ

^ o

2 E VI o

o

• f o

e fi JJ CJ

CO

QJ u - ^ ft Cd

, 0 4-> M H CO

•o « CJ x : Id H c CO CJ CJ - o

iS 8 CO CJ ^ » -_ 4-1 Cd o

E JS cd o

8 § 1) l-J

CJ

o

73 CJ

"ed CJ

CO

CJ O Ci Cd u

C PJ

CJ

es c

c m

" ed CJ ed CJ o

c CJ U l

M H H CJ

.T* 4->

fi I CO G a "ob CJ CJ X X CJ . ^

•fi X

CJ .-t4H < o -

• c

Id .2 X CX

CJ c j i i •-" 4-J CO

o .ts CJ Ci

JS 3

D C4H

D CJ Ul

3 CO

I J X CJ

00 L H

•2 .O

3 O >^

CJ

"a, ed

4-> ed

2 e

f CJ CX X

PJ

fe^Q •o

CO fi CJ ci fa o ed CO

X CJ ^ ^ CJ Q

C4H < 4

I d CQ _ ;

-? ^ -a> X ) ed

fi -o -fe 0 « ed

CJ " CJ »-i _e t i 3 71 cd 1 ^ o O Cd O

•Tt CJ y CO CJ X 1) »-i CJ u ed

jsod qig jsod mg isod qj9

85

i

o

ti u z ti ti

nnnn* u nnnn i nnnn ^ nnnn

UI n

CN

5tli post

^L

oo

nnnn nnnn nnnn nnnn

nnnn nnnn nnnn nnnn

»

C/)

O u X ti

.c

e

I u cs

c o u

J a o

u E o o

o

1

u O

c u EE t = CL X u •

c cs c ii

D 00 o

c

f

t ! ^

t4H

o

D C<H

x : "O CJ I" 4J . ^ - d

E CO CJ _ CJ - o O 'n Urn " r« O

5S CJ CO CJ ^ «-

X t: o c CJ

X

•o CJ

4—• ed o o

ed o

ed CJ

8 ^ CJ ^

a ^ ^ X

Vi — OJ

Ul

3 CO O _ 00 O CJ

CJ o Ci w _ Cd X X JS « •'-' c X 5 W -fe :£

cd • CJ -

^ ^ <

OH Id ^ - X CX CO kH

P CJ c cd - f i

u o " CJ

fi X

a . CJ T3

- i - ' CJ ed

4->

ed c« C T Q

— •o

CO 4—>

'£ 3

^ QJ k-i

3 CX

CJ CO X • -CJ cd

O fa ci: ed t i x : 5 CJ O ed >» CJ Cd C4-1

~ O Cd CtH

C Cd CJ X

£ CJ

•s §

"6 06

^ 3 CJ CO

Px CJ

CJ c c o CO u CJ CX

Z 2 < •fe OQ Cd \ ^ 3

T3 -fa

o QJ

§ ^ CJ 1 )

X fe CJ Ul CO Cd CJ

S Cd CJ «-• U . CO

86

jsod qjoi

87

nDDD nnnn anno nnn

ti u z ti ti ti

so

UI lt7 UI6

^~1 'innnn nnnn nnnn

innnn

nn nnnn^n •nmnn

u X ti

s

jsod qjg

88

E

CJ

If u cs

!= 'E o u

U O

CJ

B o o CO CJ

CJ

X

CJ 4—> Cd CJ _o CO

CJ CJ Ci Cd u

4—• Ci

PJ

2 m

— ^ ^ H

Cl o. X i> cd

CJ kH cd CJ o c CJ

li C ( _

S . 1 -

•

CkH c d

z: X ed * -

X -u < (U ••

X *-o a CJ CX

X Ci ^ • ; ; ;

4—• •—H •—"

^ c

^ 3

CO Cd

.^H 4-> ^ cd

S Q Ul ed —• CO £ CJ o

(4H U O CJ

<4H CX

•f Z ^ < o OQ

• ^ - ^ . fi Z H « ^

• CJ xi fi 3 ^

CJ o ^^ u " .£

•-5 •§ •o ?> fa B C CO c o CO Yl

ed CJ O CO CJ ^

CJ c a

D oo o

CJ u 3 CO

1 3 X CJ u

. O

X o — -^ Cs ed .£ -o

3 O

a Id

TS 4-> ..!« CJ Cd ed 4S c * - ' c tob ^ CJ • « flj

• C CO ^

fa W £ . 52 W3

ed CJ

CO S kH ed

ed •d

Ci

• £

CJ

o c CJ I H tP M - l

O CJ CJ kH

4-^ o c

«

c

CL

<§-£

CJ o c CJ

a ^ CJ CJ ^

I ^ -"2 3^^ «> S x CJ - S ^ Ul O • -3 X ^ CO fl>

^ X •£ O O 0 0 X Cd CJ CJ CJ X

U l CJ CJ " CX X

PJ

CJ Ul 3 00

89

o u X ti

^

ii cs

!r 'E o < j

u o

Cd < C3. X ii

« c2 £ '^ 2 -G W § . • >^

u o

• u u c

c

D 00 o

c 2

«

c CL

t | -

ed .•— CJ - ^ u O cd CJ O ~ Ci 1 )

2^ £ a Cd

OJ ^ ^ CJ fli X u * -3 Ci CO - 3

^ T D O CJ X -s ^ —4'

X 4—•

- O Cd 4J ^ * - •O CJ Cd 3 3

•o cr §.£

X CJ CJ 4 -u Cd Cd o CJ o CO - S ^ CJ *" u fa Cd

a Vi • O j ^

CJ rt t i *^ cd CO CO X H CJ " ^

•o CO ii

O CJ ed CJ

fe -4—>

CJ o

c 4> CJ kH >-•

U CJ

CJ ^ kH ^ CJ t -J U X

3 _c CO " S

^ s X c: CJ .fa

_c ^

90

nn nnnn

^ n n n Dnnn

ti U Z

ti ti

91

APPENDIX B

SUMMARY STATISTICS FOR PLOT A

92

^ s CJ

Cd CJ

• O Ci ed

4-J Cd

4—>

X

X

CO

4

CO 4—> 3

j d "HH

CO 3 CJ

I d

CO 3 cd CJ

£ OJ

CQ CJ

Cd 4-»

X ed

X I—>

CX

"i E 2 S

C

S

_c ' N c« u

o

03 • ^ - >

X ed

X o CX

CX

2 ^

cd 4—•

U

<5

O "d-

d

O 0 0 oo r-; i n ^ «n -H

O rT) vo CN

O N

-H

O 00

"d-

O m 0 0 0 \ ui od «^ +1

rn

CN

O p m 0C3

-H

«0

-H

O •d; r n O N ^ -H

O vo vo »n -d--d-

i n -H

O ON 00 C30

i n i n -H

O ON CN 00 i n i n •n -H

O i n CN —< rn vd m -H

-H

o oo ON -d-

O i n -d- -d; CN 00 m -H

O vo • ^ — :

i n ON 'd- -H

O O \o r-; -H " od ^ -H

i n r«^

-d- -H

m vo t-. vq CN r<i "d- -H

i n i n -d; —.

m -H

ON OO CN

O CN

<N CN

OS

ON O O CN -H

ON OO vd

r^ r-vo 4

Os CN

o 4

o p CN OO

C3N vq od CN

m m

-H

vo O ON

oo ^ ^ -H

VD CN r 5 CN '^ -H ^5 •^ -H

d S vo ^

r o vo rn t^ i n ON CN -d -^ -H

r-j vq CN ^

r- -H

O O N VO CM —J CN "d- "d-vo -H

O CN 0C3 - -CN - ^ i n oo f ^ -H

O O

VO C3N

o o o <N

. S -w

"5, *| E S 2 c

\o ^ ON 00 CN -H

O O O r n vd -d r- vo r^ +1

r«^ CN r^ CN O N CN o m m -H

O vo o r~;

d —'' o r-~ r^ -H

O rn •^ 0C3 CN CN O m r^ -H

O vo vq T f i n rn CN m m -H

o ^ O i n d vd CN -d-n -H

O —' CN O N

Os vd ON mi CN -H

o "d-oo rn CN f<S O N I ^ <N -H

O p od vo ro

ly-i

-H

J

o -^ CN '^. r~ CN vo m m -H

o vo •d; vq od r- m vo en -H

O vo oq i n od d CN ON ro -H

"d-

d : 00 ^

00 • d ;

CN m

^ :2 oo

+1

-H

O fO vq CJN CN CN CN m fO -H

O O

p p i n i n o m m -H

cd

X ed

C ed a S ;2 •o c ed u

o ed

CQ

u

ed 4-.t

X ed

X o OH

« 00 ii c

:^ ^ & 4

" E 2 5

ed . ^H

X ed

X u

CN m

o oo 00 - ^ —' od m -H

m

d - d -

CN C3N

vo r- r^ -H

O O

O CN

d -d -

o o CN i n ON i n <N +1

O P m

m CTv vd

vo vo

d CN -H

O O vd •d -

o "d-d vo

CN 00

+1

O N CN i n

O ro vq r-•d - CN CO -H

o "d-vd i n

i n CN vd

4

o •d -d i n

vo ro vd -H

O O

ro p m i n fO -W

o r-vo -d-d r- -d- +1

O 00

ro vd -d- -H

OS oo od vo

O vo p -d-ro ro r^ CN

O vo O vo

K d r-- CN

vo -d-vd -^ i n —^

vo VO

ro O p ro i n i n —

c^ r-" vo C^

ro O r o 0C5 v d CTv

CN CM

d

vo i n o r-—• -d-'

O C3N p vq od r- vo ro

O — o i n —• Tt" r-- CN

vo i n vd o

2 <N

O V O o vq ro vd C7N +1

d S oo ^

o oq •d-' CN ro

O 00 'd ; —. CN i n CN r -ro -H

O • d -

ro

O vq

O ro

00 i n CN vo -H

O CN

O ro

O OO ^ m

CN

vo i n -H

o vo vq ON O N CN OO "O

r o +1 CN -H

O rs oo vq vd ON

oo

o o

00

vo ro CTN ON (N -H

o o VD r-~ ro

C ca a S •o c Cd u o

o vo ro "d--H

^—s CJ)

a Cd u em " N ^ H ^

ON ON ON

C ^

•- t i

E I

O ro CN CN i n r o r o 00 r o •^

O r o oq ON rr ro O rr ro +1

O o

vo CN

00 oo 'd-ro

00 -H

oo ON CN ro

o r--p -d; T T CN OO r-~ CN -H

o t^ p p d od 00 r -CN -H

O i n ro "d-

o "d-"d-* "d-

in CN

-d -

o o vd 00

m

vd

00 o

o vq od C7N CN

O vq i n Os CN

O

ro i n ro

C ea ii

C ea u

a

X H

o I H O

4—•

o a ed > ^

X • O CJ

CJ Ul a CJ kH

CJ X •o a ed ed CJ kH ed

r4

00

"N C3 u 60

CN

O ed

3 O

1 3 CJ Ul 3 CO CO CJ

CJ Ul CJ

kH a '£ o o •o

CJ X

VH

a Vi 3 ed CJ

- \ ^

93

CX

3 CJ

eO QJ

g 4-J

eO

4-J

-^

X

X CO

-H

Ul CJ > o o Ul eo

Ul

c2 CO

CJ

CJ

CN

CQ CJ

c cd

S •T3 C Cd u

a .^H

ca 4-* IS ed X >—> tin

C ea

•o c ea u a >-J

• * -

Vi e 4-.> S td •*rf .^H

C X NH ca OD X •E O SS ^ u

O

c ea (U

s •o ea u

o ca

Hab

itat

U S

O WD

o .= i t g 2 ^

H

^H—^

eo

u C cd

Z

S

X

, —V

00 Ci

1 ca i2

Z

S

K

"E, E ca ^

z

s

ffi

•^4

"5 c C NN

—— CN CN — 1

"d-oo

d — H

ON Os

CN — H

-d-"

-d-CN -

ON

OO

ON vq

vd

"d-ro od

1 1

_ VO in

5, ON ON

d

^ r~ CN -H

- H

r-— 1

+1 "

^,^ 00 r-; ro -H • - ON ON

a — in •d-—-4

ro in CN 4j

./^"V

ON ON CN 4j

^ p ro 4j

_ CN ON d 4j ON in r- ^^ CN

vq

4

o" CN

-H

ro CN

^

E

ro 4—H

d <—1

-d-vo od

vo p — H > — 1

in vq in CN

•d-^ H

TT •d-

Tf vq r-

r--in

00 ON in

CN od

O vd

CN ro

^ m ON C3N

ro vq CN -H

m oq — -H ^^ . CN r-; fS -H —'

— o d "—I

-H '^B*^

vo in

in CN

4| /" • V

— ro TT +1

r^ ro in 4j

. OS in

d 4j ro r vd _ ^

p

_ in ON

d -H

oo oo

d +1

S

4—H

vq CN — H

, -d; CN — 1

o t

d —

C3N t d ——

'd---I

d

rr ON vd

cs oq od

vo vq r-

o Ov CTN

. OO vq 4 -

^ H

ON

-

—— CN ro 4H

in vq CN -H ^ • ^

^^ m 'd; ro 4j

,,- —H

oq CN -H — CN vq fS

CN CN rs 4j

/^~v vo ro •d-' ^

^ OS TT 4j

_ in p ^ +1 -» ON r-; od __ ro ro CN

+1

^^ t

^

in

p CN

4j_

J

VO p ro - H

ON ro CN

fN vq <N — H

CN ro

—H

CN vq -J

r C3N •d^

ro

od

ro

vd

r-

'"'

^^ oo in

^ - ON vq CN

^ r~; CN -H

vo oq CN +1 ' ^ ^ ^ fS CN ro HH

^-^ r ON

" —• -d-vq CN

—H

Ov CN +1

, V VO in

d +1

f ^ p ^ +1

. "d-*-"_ — H

+1 — VO r~; od

ON

'4 ~

-d;

J

ro

fS

+1

Z

O ro p ro CN ^ — -H

r~- CN

p —; 1—4 - H

^ Ctt _

r- -d-p in ^ -H

^ it

Ov OO p CN d od CN 4j^

.^ vo oo vq p CN CN

^ it

CS ^ O vq rf CN

^ it

^^

'"'^ ^^

^ vo CO .

^ 1

^ ^. od O

"

d ed -v »J DO ^ a C u ed DO

o

c ^ « 00

Me

lin

ea fd t -b o ^

-d-> — 1

CTN

m "d-r~-

Ov <n in

cd 4-> •-H X ea X

; S : ? - - 5 o o ^ < N g ^ Z ' ^ < 3 ( . ^ ' d : o o i n ^ v q

^ ^ f ' ' ^ + 1 ' ' ' ^ ' ^ f ' ^ 4 ?

2 ^

en N e« u

o

+2

X O

X

c C3 0 0 ii

"S B 2 2 a ^

ed 4.J X ea

X

u

ro

<?N

ON

CN CN -H

SS , ^ m 00 CN [;; - ON ( N

ON CN . X — -H V ) -H

O ro — -fl

r^ t^

r-

CN

vo 00

CN

r ro 00

Ov

ON

m o r oq 00 CN CN - ^ T f -H — -H

i n vo vd

4rt. f ^ rr^ CN

js: r . i:; 00 ^ 41 ^ 4 i n

CN ro

4

00 ro CN 41

• d ;

o; ^

-d;

ON vq

41

CN i n

CN 41

ON

ro Os ro

-H

ro i n

o ro i n

i n 00

vo Ov i n

o oq >n

m vo

OS CN

O , ^ ' -41 i n 41

i n o vd

CN

ON ON ON

1-H

Pi

C ^ •- ti "a'2 E " OJ

vo g 00 li m i2 CN " ^ t ^ ^ VO .

'd '5 rr "H od '^ 41 41

Os

i n CN

m

C3N

41

m ro 41

o . - ;q. - g; - 00

CN

oq

vd

O N

od

VO i n od

m

p

-d--d; od

X

o ro i n

ro

i n

vo vo vd

c ca ^^ a M C u ea 00

{4H

o

o

CO

>% X

•o CJ

O

CJ I H a CJ I H

CJ X

•o

ed CJ Ul ed

£ CN

d ed 3 O

CJ u 3 CO ed CJ

CJ

u CJ

Ul CHH . 1-H

3 O o •o CJ X

u

CO 3 ed CJ

94

X ca

X

3 CJ

ed CJ Ul

4-> 1 3 3 ed

4—>

ed

4—»

• |

X

X CJ CO

-H

CJ > O

o I H CJ

eo 4 - J

o 4-> Ul

a Vi CJ

£ CJ

CQ CJ

c ed ii

O VO

i n ON o

vo <N ^ vo

5 - ^ NO ^ . ro ~ 00 CN ^ c N v d : : : - H - 2 2 d < N

i t * ^ 4 1 * ^ 4 1 ' " ' ^

00 O i n - H (JO

VO ro

i n 00 Ov

^- >n oo ^ ^ ^ -^z:

Os CN

i n C7N

ON

41

CN m

oo CN i n

i n CN CN 4 1

vo "I? vd ^ TT VO

41 41 Q ^ — 41 ro 41

S ^ •O

c ea u

o

I ea is

(/i ff 4—> S Cd V 4->

•*rf . - H

fi -S ^m ca UD X

.s o u

« 60

CX

2 S

ea 4.H X ea

X

u

ro oo "d-CN

- H VO r-; ro d od ro -H

IT) m i n

i n oo o r~- i n ro

i n

oo ^^ - ^ - ^ 41 «N

t ^ vo CN ON 41 CN 41 <N

ro

41

ro O O r o r ~ i n v o o _ j — _ ro "d; CN ro CN . p p d r- CN ro - ^ 5 "^ fS (N 41 CN 41 ro 41 ^ 41

CN o i n - ^ oo r - ro m

ro - P i S r^ ^ <=> ^ ^ ^ 00 ^ — 41 ro 41 ro 41

ro — 41

O oo

CO

m d vo

OS oq i n

m CTv

vo

ro ro — Ov

CN VO VO

CN VO

VO i n i n

vo

O ro O <N

vd ; i ; T t ; i ; t ^ XH 00 VO vo 41 vo

o Jjd o

41

ro

vo 41 oo 41

f S O m o XH

o o o <N P >^

00 G

ram

pli

H

r ISU

nte

^ H

O "^ • ^ " : • ^ ro ^ v d ' ^ r f ^ ^ o d r ^ ; : ^ 'O ^ NO ^ NO 41^ m 41

ro NO

- - ^ <N VO r^ -d- m oo ^ . oo . -d-

ori CN _ j o _-• - ^ oo ro 2 2 — ^ 1 — ^ — m ^ -^ 41 ^ 41 "^ 41 41

oo in od

O oq od

Ov ON

m

CN

m

CTv

CN

ro

CN CN

VO

i n

p ro vo

c ea <u S •o c ed

CTv i n

—. DO

N Pi u DO

o

95

o

3 CJ

ed CJ

•T3 3 ed

• ^ X ed

X

X

'c? CO

-H

CO CJ

o CJ CX CO

CO CO CJ

•c "eo 4—'

o 4—> U l

a Vi 3 ed CJ

CJ

CQ CJ

e ed a S 1 3

ea u

o • ^ - »

2 X ea

K < — > CX

c ea (L>

S •o c ea u

O >>

'^^ M

5 -i eo X S O N )^ SS CX u

o

c ea 

u H

'BO

Q^ C ra

^

2

S

E

DO c

1 ed tJ

z

s

K

'oo

"s-E ea ^

z

2

X

4 i J

s OJ

B NH

o p i n

o oq i n

o oo -^

ro ro

z^

o o d

vq r-

o oq r~

o -d-od

o o d

_ o vo d 41

N ^

o CN «n

• ^

41 "•

-^^ vo vq

d 41 "^ ^.^ ON

ro

J r^ 00

d 41

vq Ov

^—V

ro ro

41 ^—'

o o d 41 ^•^

_ ro ro

d 41^

_ 1—1

r--d 41

ro r-; od

_ ro

d 41^

^ , •d -- d ;

_ r o -d;

41

X

o oq i n

o oq ro

p i n

O

o ON

o p •"

ro ro

d

o p Ov

o - d -

e?N

o od

__ ^ vo m d 41_

r-0 0 "d-*

p

41 ^—'

^•^^ O 00

d 41 ^•^

_ O p ^

i n vo

d 41^

, o

.—s

ro i n

41 ^—'

i n

41* ~

_ vo vo d 41_

^ ^ ro VO

d 41

ro CTv od

^—V CN i n

5 _

CN

^ . 00 vo

d 41^

S

O

»n

o vq i n

o vo T f

ro ro d

O p r~-'

r o r o od

O

d

o CN OS

O 00 ON

_ <?v vo d 41

> — •

O CN i n

r^

41 ^^

,.—V

i n

^

_ ro p ^

i n r-d 41^

vo i n od

y - * v

vo vo

d 41 "—'

oo m

d 41 —'

^^

41 "—' ^ ^ r i n

d 41

o oq ON

_ ro ro

41

- vo p

^.^ CO m

d 41^

J

o o •d-

o CN •d-'

O - d -

T t

ro ro od

vq od

vo CTv

O rs od

o -d-

d

o vo ON

^.^ Ov ro d 41^

O CN TJ-*

d 41^

,.—^ 00 i n

d 41^

_ .

oo

d 41^

ro r-d 41^

ON

oq od

ro ro

^

CN

41 '"^

^ ^

vq

41 '—'

^ ^ ON VO

d 41 *—

O "d-ON

^.^

ro

d 41

^^ oo oq

41 " '

^.^

0 0

d 41 ^~^

z

S? ^ g

' '"S

oo ^ W 3>

;tt ^.^

s ^ ' S .

^—s

1/-V ^ ^ > ^

^ s

: : ^

o o ^ • ^

^.^

§3 o< 5

^—'

^.^

00 . od O

- 1 —

o; o ^ '

^^

- 3 =.;o

"

C u ea DO U N ^

o

C ea

•o B ea u

o

tat

J H

abi

CX

c ea ii

2 t 3 C ed u

o >> **

c#t

Inte

n!

abita

t

UD S

g &-h. u

c ea u s c ea u

o

itat

X ea

X u s

ON W) ON . =

Pi u H

/ " ^ K DO C

1 a h

Z

S

ffi

_ DO B

1 ea

z

s

X

DO C

1 ea

z

2

ffi

'c/s B

B

O VO

-d-'

o CN i n

o oo •>d-'

r o r o Ov

O O C3N

vq od

o

r-'

o vq od

o "d-OS

r^ 00 -d-'

r o Ov

d 41 ^^

/^^\ O CN

41 •

^—N VD

. 41 "

o o C3N

y i ^

00 oo d 41 "

_ ro i n

41 "

..

vo

d 41 "

r--d; od

i n

d 41^

m

"41 '—'

__ O vo

d 41^

K

o vo -d-'

o oq ro

O p i n

o p od

o o d

ro ro od

o • d ; od

o • d ;

od

o vq r-"

t ^ -d-

rf

ro CTv

d 41 "~

y * " ^ ^

00 <n

d 41 "

/ • ^

ON 00

d 41

00 r- od

^ - v

ro

41 '"-^

_ ro i n

41 ~

_

vq

41 ^—'

ro - H

od

r o Ov

d 41 -

i n • d ;

d 41 "

^ ^ 00 vo

d 41 •

S

O oq •d-'

o p i n

o oq ro'

O p CN

O

o CTv

O O r-

o CN od

o vo K

o CN od

ro m "d"'

p

^

.. ^ oo -d;

5, ^ — * s

Z^ ,

41 ^-^

r o r o Os

^*-v m

41 "~^

^ _ oo i n

d 41 "

^^ O

o d 41 "

O

p od

f S

vq ^

t ^

41 ' "

_ vo oo

d 41 ^•^

i J

O VO

"d-'

o vq ro

O oq ro

O

p od

r o r o

d

ro ro

^

O OO

vd

o CN od

o oq r-

o o -d-'

-.-•v

i n

5,

ro OS

d 41^

ON

d 41^

C7N oq ON

^^•^ oo i n

d 41 ^^

_ O -d;

41

_

o CN

41 "

O vq r-

ro

^

vo ro

41 ^^

^ ^ r o CN

41 ^ • ^

z

i n vo r f

o •<d; -d-*

m ro • ^ '

ro ro C?N

00 i n Ov

ro oq od

O

r-

o CN od

i n CN od

B ea ^ ^

a 5P S .s B u ea DO

o

eo CJ Ul ed

£ CN

o ed 3 O

-a CJ CO

ed X

CJ

Vi 3 O

CJ Ul Ul a

*£ o CJ

T3 CJ X

£ ,3

CO CJ

To > 3 CO CJ

96

APPENDIX C

SUMMARY STATISTICS FOR PLOT B

97

&

c CJ

a CJ Ul

c cd

cd

ea

X 'cT CO

-H CN

£ ~co 3 a

CO

3 CJ TD "^ 4—>

o 4—• Ul

a Vi CJ

£ CJ

s

CJ

>> ^rf

*5 B

[nte

az

in

u CJ

tat

.o

PJH

al

Xi

^-» Cd

•^ r f

GH

ab

OH

•• 4 - *

ibita

CO

X u S

o o o r^ f IS

M

C eq 4> :E "O c e a

c

Mea

ra

nd

O

c es a> S

rand

O

M _B ^ E

H

y ^ . \

00

impi

3

z

_J

S

X

.. eo

plin

tr

am]

z

-J

S

I

y - N

eo c

:^ E ea t :

Z

_]

s

X

>> *5 e 4* C

o <N ro •V

O vO Ov ^

43.4

0

o p r- TJ-

vo

0 0

o p vo

ro

5.3

o

vq

0 0

o vq ^ o •<t

o vq r- ro ro

O

f N VO TT

O

^' P-. f O

8 f N ro •*

_^ • V OO

vd M "^^ o 0 0

</% ^

r-f N

O 4j

>«.K

vO « < - ;

^

, . . >

) (±

18.5

5

• « » •

ro

^ 41

^ • s

o

(±15

< '^ Z

Ov vq

;±I7

f N

4.7

— 41 ^^ ..

ro

±41

^ • ^

,^m^

o >o od «n 41 •"

.58)

r o f N

"^

.10)

IT)

.-- f N

vd f N

^

.06)

ro O 41

I

O f N

f N

vr>

O

7.8

T t

35.0

0 o •^ vd >ri

T • ^

ov

o p od

o

4.0

ro —

ro ro

r-

o p od ro TT

o vq «-i f N

•<r

o f N

vO T f

O f N

ro O </

o o vd <n ro

_, <ri ro vd 41 ..

1 / ^ 0 0

r- T t

s~ o vd 41

«

14.9

6

41

) (±

9.09

) f N Ov

OO

^

/^ f N ro

(±17

< " Z

vO r o

:±2i

/ . - .s

c>

3.5

TT 41^

69)

(±7.

^ . y

^. 0 0

TT >o 41

.53)

o ro 41

• ^ . * '

.55)

ro

5, ^ • N

f N ro O O

^

32)

od Ov 41

S

O vq ro ro

O

4.2

T f

55.0

0

o f N

ro TT

f N f N

vd 0 0

ro ro ro VO

45.6

7

vq

149

o f N

• < *

VO ro

O 0 0

d •«r ro

d Ov CN

o vq f O

<o ^

o p f N

r--ro

_^ f N VO

•<* 41 ^"^ O p T t rr

^ l o

wS 41,

l O

6.0

41^

,_

(±15

.53

f N ro vd 41 " ^

_ P

(±22

< '-- Z

vo

:±i5

y—.^

>n

4.7

^ M

41

y — s

o "1

±47

^^

...... .— c> •>r • *

41,

•^ 0 0

T t i n 41,

05)

ro Ov 4^

^^ vo vo od 0 0 41

.74)

ro CN

^

- 1

o vo o\ •*

o

6.2

ro

41.0

0

o r r >ri T f

o p & •

ro ro

ov

(

6.6

o

o p

O •>* • ^

ro t

O p od f N VO

o f N

o •^

o vq ro r~ f N

o oe> od f N

•*

,^ ro vo •< | -

4^ >ri

p ro ^

« N

"" ^

r~

7.0

41

^—s.

(±11

.63

r-ro od 41 '"^

_ o oo

(±14

< Z

iri

;±40

oo"

0.2

f N 41 —'

^...^ 0 0

p

±18

. - • s

vo o CTv

r— 41 ^ • - ^

.31)

±2

62

^^

.38)

l O

41

^.^ O

vd r~ 41,

00)

ro 0 0 41

Z

t o 0 0 vq —. ' J ^ • * 41

vr> ro

rr iri •^ 41,

43.6

0 (±

6.71

)

O vo" P p od vd • * ^

< Z

f N * >

ro •^ 41

97.9

2 ±1

4.81

• ^ ^

^^

s§; ov ^

>^.y

O f N O 0 0

ro od ro r— • * 41

o G" 0 0 Ov vd — O vo •^ s

... o o f N Ov — «?v

o .^ •* a.

CM Ov

K r- Ov . ^

•^ i .

c ea ^ .s ii 0 0 S .E

Gra

nd 1

(gra

zi

2

abi

I •-» CL

,,. CQ

Hab

i

a a.

>,

» " e •

Inte

l

bita

azin

g 1

MC

Ha

L.

o

Os 9s Ov * H

>

C ^..s

a eo

rand

tra

mi

o •^

z

-J

S

I

c ^^ n eo « c 2 ^

rand

tra

m;

o •^

z

-J

S

X

C , - v ?! BO

S J

rand

tra

mp

O w

-J

z

:s

X

e >«

ram

pli

Inte

nsi

H

o 0 0

o ro

O •^ ^ f

o 0 0

ov .*

o o vd ro

o p od <o

vo d Ov

ro ro

O^

O p

115

o vq ro —M

<o

o f N

383.

o .<r d Ov f N

o vq <o

«->

1 / ^

r-; -^ ^

>.*» ro «-) o 41,

.28)

f N

1.29

) (±

1

vo f N 41 ^ • ^

_ 0 0

r-; p^ 41,

vo f N

d ov

p -

p

±13

^^

^^ ro

±14

r-

(±6.

,_ o >o

±36

^^

o f N

od ro TT

O^

±257

.6

7)

±105

'—'

0 0 f N

f N 0 0 4 ,

f N

±234

•> - • '

X

o TT

f N >r\

O 0 0

^' ^

o vq ^ ro

O p f N • ^

P -VO

d Ov

vq ro

vq

106

p~ vq f N OO

o p f N

— ro

O f N

363.

o •* T t ^ - a

T f

o p f N ro •«r

o r~ f N V

^ 0 0

r~ 41,

.80)

f N

^

«r> Ov

>/S 41

,,. 0 0 ro vd 41,

f N • ^

od 0 0

ro

±17

^^

. ^ oo vq

±15

*>—*. ^

±21

^^ ^ " v

vo f N

±23

"

o T t

d oo ro

^ T t

f N 0 0 41^

(S3-

±124

^^ . vo

0 0

o

5, vr>

196

41,

s

o vO

vd ro

O f N

r~ ro

O f N

<ri .*

o f N

r~ •^

ro ro vd < 0

ro ro d oo

vq

ov

ro f O

116

o f N

ro vo ro

O O

260.

o • ^

od — • t

o f N

TT

</ vo ^ r r

1.06

)

c> 41

y**n

T t

vd 41,

r-r-; od 41,

_ P~ O <> 41,

r--— vd oo

f N oo

±26

^•m^

/ - •V OO vq

±10

ro

±26

^ • ^

y—N O N

±31

*~

o f N

f N

|-~ f O

m vo «S r~ 41,

23)

(±67

.

r~ •^ C?v

<o 41

r^

132

41 " .

- 1

O TT

1-^ T f

O vO

d TT

O vq f N ro

O OO

f N TT

o p 0 0

o p oo

ro ro

140

o o d

o o vd K M

VO

o

450.

o o d o ro

O p od

<n

l o 0 0

d TT

o" Ov

«S 41

o" ro .«r 41,

0 0 0 0

T t 41

. o I O

o 41,

ro ro V~l Ov

ro O ro 41 —

<«-*v

O

±25

CJv

±27

^

29)

(±5.

o vq od r~ • V

vo ±2

77

.99)

±1

47

" • ^

. . • ^

0 0 ON

^

ro

f N

f N 41 ""

z

<o o T f T f

o p •^ f

o 0 0

<Jv ro

O p f N •«*•

o p ro

p~

f N 0 0

p

109

o o vd o^

o f N _J >o t

o f N

364.

o 0 0

<o <o ro

O f N

od Ov

^

c ea .-V i> eo

S .E

rand

(g

raz

O

TT ( M

o I H

o •^^ o .CO V M

C<3 >%

X T3 U

ipli

^

mul

.. u u ,o C M

a> U

X «-* "O B ea

u (0

•M

B <o CN CD

Cd

B O

-o ii I H

3 Cd

u E u I H

I H

a • •"N

B O u

•o u _x g I H

o cs V)

B CO u S

o o o CN OO B k .

O. (/) B

• ^ *

o Cu B

•» ( / }

CA

>> CO B CO

E o

<i: "O u > o £ ii u. U u ii ^ vt *^ B 3

•o u CL

.9* ^.^ o 1

B O B

— CQ

ii u. a ii I H

ii X

H •V

•o u •«-»

ea ii

a >»

*« 4—*

B

!2 o CO ii

X o «

B 3

"Q ii U. a. —* o

1 B O B

CN _B

T3 U

"s c/l

o t a> u u

c/> X> O

98

3 CJ

ed CJ Ul

• 4 — •

3 ed

ed

-^ 4:: >^

CO

-H

CJ > o o Ul

.2 Ul

a Vi i CJ

CJ

2 H u CJ

lean

ra

nd M

0

.4—*

ed <-> X ed

1—>

C CQ

u 2 • 0

c

0

X ) •*-^

CQ ^4-^

• ^M X ed

K 0 cu

CO (U

2 •a c C3

0

^ • • • Vi "

B t i « iS c 15 « ed OD X

u 0

2 M 0 =

B » Pi 2 >^ H

'eo c

1 t

z

- 1

s

X

^^ eo c

"Q.

E Cd

'**'

z

- ]

s

. . ± .

'eo c

"a. E Cd fc.

z

_)

s

X

>. B

e

Os r o

d ~

• ^ Ov

0 VO

vd

_ ^ 0 ^

0 0

o--_ od .—

1 0 f N

0^

VO 0 0

•

0 0

_« 0 0 ^ M

^ •«1-

d

rvi

vq od

ro

5, Ov

od

Ov~ 0 ^

" 41

VC

CN 4^

ro p ^

• CN

r o

4j

^ >o — r o 41 ^ • " • ^

VO r o

•

<

z

y — V

0 ( N

vd 41

, . 0 >o ^ 41 ^ ™ ^

^ r~ r o

r- 41^

.. T t 0 ^

vo 0 0

ov

T t r^ f N 41

^^ VD Ov

wS +1,

l~~ <o

^ 41

^ 0

fv j

4j

^

<o

— ^

r o

od

r o PvJ

d

vo r- r j -

0 o v

r o

.—

( N

P f N

—

1 0 ro • ^

r o

Ov

OV 0 0

0^

T t 0^ CN ^ M

ro t~^

^^ r o r o

5, VO

d

O; rvi 4^

• ^

rvi 41,

C?v

f N 41,

1 0

p r o

41 ^ . 0 0

0 0

f N 41 v.—^

ro • ^

r o

<

z

y — V

— 0 0

vd 41,

^ • ^

vo ro ro 41 """ ..

r~ r o

vd 41,

. >o • ^

3 ,

ro Ov

CJv

0 0 1 0

TJ-41

, p -0 0

f N 41,

^ p f N 41^

s ^

s

>o ro ov

• ^

r^

d

od

0 0 f N

^ -

f N >o d

• *

1 0

vd -

ov 0

P-^

Ov • ^

vd

ov CN

OV

P -p~

0 0

>o 0 0

0^

,_ ( N

p

ro 0 d

p -Ov

rvi 41,

0

f N 4[,

t ^

d 41,

r-0 0

^ 41,

. vO

• r o 41,

<N P -

TT

< ^ • ^

z

^-.s • ^ p^

'T 41„

, , 0 0 0 0

>o 41 ^"^ ..

0 0 l O

od 41,

. -0

ZZ-0 ^ ^

S^ 0

r o 41,

^ ro 0 0

f N 41,

.-^ 0 0

-4^

^ 0 If-)

ro 41,

_;

0 OV

^^ "—

ro 0 0

O

p~ 1 0

vd

~ — d —

t ^ p -

-* .—

r o

c<

o v r o

vd

( N vq p-^

ov f N

d

p -

Ov

f N 0 0

P-^

s f N 5, 0 VO

0^

< o rv)

f N 41,

zz r o 41,

vo >o ( N 41,

S' vo ^ 41,

. 0 0 O; f N 41,

ro vq ro

<

z

.- o v r o

vd 4^

^^ f N f N

>o 41 ' " • ^

_ r o

— >o 41^

^^ 0 0 ( N

f N

r o f N

^

0 0 ov P~ 4^

- 0 p r o 41,

0 0 0 0

rvj

41 ^ • ^

^^ OS

5,

Z

0 p^

d

0 c>

vo p 0 0

f N 0 0

d

•* >o '^

0 0 0 0

^ —

1 ^

vq iri

<o p r o

.—

f N ro

d

f N r o

d -

^ 0 0

c ea

•0 C3 1 -

0

0" f N

^ 41^

0 f N

5,

p

5,

rv |

_J 41

<

z

. ^ . . y

<o P-;

f N 41^

. • ^

p rvi 41 ^ ,_ ov <Jv

f N 4^

G" >o f N 41 >^

.. 0 0 0

^ 41^

•>3-• ^

— 41 • • • . ^

^^ 1 0

5, ..—s 00

c C4

fc

c ea u

s • 0

c 2 0

ed •^^ '^^ X ed

X 1—»

OH

c ca u S •0

Gra

i ' * - > Cd

• ^ - »

Hab

i

0 cu

c: ca

2 • a c

Gra

*5 "

« S .5 ^ 1 — ed

u 0

OS e

R1

9 ra

mp

li

> H H

'eo _c "H. E S

z

J

S

X

_ eo c "5. E Cd

•^Irf

z

J

s

X

. eo c

"5. E Cd

•t—t

z

_J

s

X

>. *5 e

s

0 vq p^

f N

1 0

0 0 0^

VO OC)

p^

f N

P ^ -

VO

CJv

OV

P-^

0 0 vq p-^

l O

p ""

Ov 0 0

Ov

f N

vd

r o p -

0 0

<o <o p^

r o P-;

^

^ i i i v

^

5, ...

ro vq

5, _

r o

f N 41,

0 0

od

p~ vo d 41,

-. <?v

d 41 ^""^ ^^ • ^

• d 41,

^ ^ vO

ro 4^

p~ Ov

od

41,

/ . • *

TT

l O

4j

/^•^ 0 0 P-;

f N 41,

f N f N

CN 41

—

vo 0 0

vd

f N

r-

p od

p -vo 0 ^

VO <o od

p~-

r-

0 vo vd

0^

vq od

0 0

od

>o

d

OS VO

vd

0 p od

^ r-^ ]

> 41,

-. <o

5, _

f N 1 0

5, ^^ "

rvi 4 ^

r^

od

o" 0 0

d 41 v * - ^

.. 0 Ov

41 v * * '

.^ r o

5, .

P~

f N 41,

• vq od

0 " p <o 41,

^ >o 0

41

^ ^ V C3V

ro 41,

^ 0 0 <?v

5,

2

0 f N

P~

f N vO

vd

• *

vd

<o 0

ov ro f N

.—«

P od

Ov 1 0

d

0 0 f N

od

1 0

vq od

p -

0^

>o

p od

P-;

od

0 0 ro p-^

vq

5, _. ro

f N

5, .^^s 0

5, ,„.^ f N

f N 41,

r o 0 0

0^

P -Ov

rvi 41,

y . - ^

0 0 •o

41 " .^

f N

41,

. 0 0 0

5,

vo vq od

P-;

f N 41,

, , 0

ro 41

/ . r o

rvi 41 "" ^^^ rv|

o^_ ro 41 "

• J

r N 0<3

r-

vo

vd

p -

• ^

rvt

d

ov f N

OV

f N Ov Ov

VO

1 0

ro vq p-^

f N

d

r o r o

od

ro ro

"

vq rvi

ro r-

r o

vq d 41,

- l O

41 ^ v i . '

. r o Ov

d 41,

^^ 1 ^

5,

0 p od

0 0

^-d 41,

^.^ 0

41 N . . . '

•

VO p ^

^ 0

41

0 vo

d

rv |

ro 41,

, , o v rv|

r-i +1

y ^ . ^

P--

ro 41 ^ ^_ vo >o

41 * " • * '

z

r~-ro P-^

vO <o vd

Ov

vd

r o r o

C3V

rvi ro d

ov P-;

od

ro P-^

ro od

3 Ov

< o 0

(7^

0

Ov

0 f N

Ov

c ca ^ ^ U 0 0

2 .E

« 00

0 ""

TT Ci-i 0 u 0 *.» 0 .<t (4-1

ed

>% X T3 U

ipli

*^

mul

.. (1) u

, 0 U - i

u u ii

X .4-t

•T3 B ed ed ii u ed

N

B m CN 0

( d

B 0

•T3 u u U) f «

a> B a u

u ^ • ^ N

B 0 0

T3 u

mix

u n C M

c«

B Cd

a >i

0 0 0 CN 60 B u 0 . Vi

B •^ a cu E

• ^ ( /}

C/3 > v

cd B CO

s 0 ci: T3 u > 0

£ i i u u u u ^ C/)

'4-rf

B 3

•T3 u a Cu

^ • ^

0 1

B 0 B

^ ed

iT u a ii u ii

X

H ^ •T3

u 4—1

ed u h > v

ed .*-• B

T3

u CJ ed a>

X> 0

• ^ ^

C/3

B 3

73 (U Cl. a

^ • ^

0 B 0 B

CN

B

T3 u •+1^

3 Vi ii i_i

u 0 fc i i

u i i

r ii Vi

X

0

99

CQ

B

ed ii b B ed

4-» ed

ed J 3 >v

X

ii vi -H

o^

u CJ > O o Ul CJ

ca -*—> o

-t—>

U l

CO

3 ecJ CJ CJ

2 H

u CJ

>-> c« B OJ

' to' S ^ on

* N CQ U

0

1

c ea u

2 T3 c

e 0

4-> ed

• J

X cd

X O H

c ca u

"O c ea

0

XI .4..*

_2 • ^ X ed

0 O H

i= ca

^ 2 T3 c ca

0

ed * j

iS ed X

§ ^

z 1 g 2 1 ^ r-

'So

"E E

I

z

- J

S

X

^ - * s

00

E 2 ^

z

-J

s

X

^^mm^

bo _c — CL

E ca

-.—•

Z

-J

2

X

>. ' 5 e it

s

rv) rvi 41^

vo f N r^

P ^ - ^

• " ^ - ^

IcS ^ i

^

od -^

, — 0 f N CN d od — 41

""" ^ >o >o r o 41 v.™^

r o Ov

• "

< Z

^ • ^

7.70

±2

.17

~—'

0 — 0 p •^ vd rvi 41

^^ 00 vo

p - ro vd — 41

^^ r~-0 vd 41

0 fN l O VO

^ 00 r o . •o "^ r o ^

. rv| fN r~ p~ — Ov

• cH

2 ^ r j ^ ro ^

._, 00 2 ; vo ^ r^ «=>

^ 41 ^

. X .

0 0 vd

>o

p •<t

00 00 >o

>o >o vd

rv)

p- r o

rv) lO fN fN

r o Ov VD

10 00 r o rv)

p-

d rv)

VD

Ov

T T P~

_ r o

f N t - ; rvi 41„

rv)

od

P~;

41 ^ • ^ ^

/—*s Ov <o

d

5, ^^ r o p fN 41

^..^ 0

— r o 41,

- 00

"O 41,

Ov rv) CN r-)

< ^ Z

^ ^ r o

vd 41^

>o P-;

• 41^

.. 0 vq • ^

41^

^ 0

10 41

0 fN

d

p ^ VO

d 5, . , fN 0 0^ 41,

lO od 41,

^^ Ov

'~' • ^

5,

s

<o

p " •

r o 0 0^

10 vq rv)

0 r o od

fN 00 d rv)

00 0 d ro

00 "O fN

—

f N Ov vd rv)

VD VD P- rv)

Ov VD ro fN

Tir o lO

10 rv) 41,

vO P-; P-

41 ^^

0

T T

41_

/ - " V ro rv)

5, .

^ vq 10 4^

^ 0 rv) vd 41,

vo — ^ rv)

<

z

(±15

.29)

o~ CN

5, , ^ VO fN fN 41,

- Ov Ov ' I -41,

0 0 Ov VO

TJ-

p rN

41 V — ^

I— r o rvi

5, C7V >o

d 41

^ • ^

vD~ 00 vd 41,

J

10

r t

P-

>o ov Ov

Ov 0 vd

00 Ov p-

p~ 00

d —

0 ^r ^ .—

ov P -

>o fN

—" d r o

Ov p r o r o

.—. ro T t

. ro Tt 41^

rv)

rvi

r o fN

5,

^ >o 41,

^ ro

T t

41 ~'' .

r o r o vd 41,

. r~ 10 rvi 4j^

rv) • ^

ro

"

<

z ^ i ^

rv) t o r o 41,

Tt fN vd 41 ^ _

t lO ro 41 ^ /—V

- T 00 >o 41 •"— 0 ro vd VO

ro 10

" 41 V . " - '

p^ Tj-ro

5, 0 00 T t

+i ~—' ^^ 0 T t VD 41,

z

^s p.: <N

•«• ov

od 2^

s ? 0; 2

--—s

g? 0; ^

< Z

.. 00 00

20.9

±4

.8

"—'

t ^ r o 00 Ov — r o

'N i t

^^ 0 <o p p — fN — 41,

0 0 " >o p ^r vd vo 41^

^^ 0 —' vD ro d "o P~ 41

v.—^

0 Ov fN vq od vo VD 41,

^-v 0 r^) TT p p- "O VD 4 1 ,

c ca ^ ^ U 60 2 .£ 1 ^ Cd ^

a

o o o f S 00 B u

a

o OH B

C/}

Id B ed

O r U M-l

T3

> o B ii

u u 0 4-» CJ

c2 ed

W -4—>

B 3

>v 73 X )

^ '-•-»

mul

i > u 0

(H u u

X

na B ed ed ii u ed

f ^ — ,

B i / ^ CN

d ed B 0

73 (U

sur

ed ii

B a u a

u t5^ M-l 'B 0 0

(U

mix

u 0

Ci B ed (U

S

lU

.2-0 1 B

0 B

cd

»• u I-I

c2 (U u (U

J3 H

-d ii

"ed (U i : (U

X 0

.4—* t/3

B 3

•T3 (U Cu 0 -

73 1 B 0 B

CN _B

13 ii

•4-»

3 c/5 ii U u 0

t ii

u (U

^ u Vi

X

0 03 XJ

100

3 CJ

CJ

3 ed

-)—> ed

•*—'

X

CO

-H CN

s CO

CJ

o CJ CO

CO CO

CJ

•c "Id

U H

CO

CJ

CJ

U CJ

c ca u

Iran

d M

O

• 4 - *

Cd

<-> 3

PJH

a

c ca a 2 •o c 2 o

J2

. ^ ed •4—<

• . . H

X) ed

X o cu

c ca u 2 " O

c: cd

o

*35 "

« S = X

( -H ed

WD ac

u o

O B

B * DS >-

1 .

00 c

1 £

z

- J

S

X

eo _c "a. E ea ^

Z

_ i

2

X

'oo c

"Q. E cd

^ """^

z

J

s

X

>. ' 5

B 4*

B

O vq >o

o o vd

o rv)

< o

o p >o

r o r o

P-^

O p P-^

o o ov

o o C7v

O VD

d

o p od

o o

d

. p~-ro t «o

<o

1— 0 0

d 41

>o ov

d 41,

, , 0 0 l O

d 41,

, , t~~

d 4^,

,-., o oo d 41,

0 0 P-;

P-^

< z

,—V

r o r o

41

0 0

p rvi 4^,

0 0

d 41,

^ VD

vo d 41^

o • < 1 -

OS

Ov 0 0

d 41^

O vo

41

<o

. >o

5,

X

o >o

o vq <o

o vq r^

O rv)

> o

o p p-^

r o r o

OS

O O od

o ( N

od

o 0 0 p-^

o 0 0

d

o 0 0 od

_ <o ro d 4 1 , >o Ov

^

°9 d 41

0 0 vo

d 41 ^ ^ o vo d 41,

.. Ov

d +1,

. , — >o d 41^

_-— od

< Z

y . * ^

o p 41

vo vo d 41,

0 0 l O

d 41,

, ^ rv) p -

d 41, o Ov

od

f N P

5, C7V

r o

41 ^•m^

0 0 p rvi 41^

^ "

5,

S

O f N

vd

o vo vd

o rs vd

o rv)

vd

o

o Os

r o r o

od

ro ro 0 0

O O Ov

O OCJ

P-^

o d

o 0 0 p-^

0 0 ro d 41, o ro vd

ro

d 41,

5, .

p -

p 5, .

0 0 ro d 41^

, vo "O

d 41

vo l O

od

< Z

— oo l O d 41

o f N

5, ro ro

5, , ^ >o l O

d 41 — l O

p~;

od

f N r o

d 41

o f N

5, Ov r-)

5, ..

vo

5,

- J

o rv)

vd

o vq <o

o vq l O

o vq <o

p -VD

od

vq p-^

ro ro

d

O f N

d

o 0 0 od

o rv) p^

o 0 0

— • t d 41_

>o P--

>o

ro P~

?

"O pv)

4?

.. 0 0

d 41

. o vo d 41,

, ^ >o p -

d 41

ov 0 0

od

< Z

^-v oo 0 0 d 41

"O

41 ^

l O

41 ^ , ^ -P~

d 41 """^ O l O

Ov

rv)

^

Ov l O

41 N ^ . '

0 0 l O

d 41 '"" .

o l O

5,

Z

«o ^

• i

. O » OV ' ^ .

^ § ^ g

^?5 '^t

< Z

y«-V

8 ^ od O

§ ! od ^

^^. od o

N.- i '

2 ^ o; ^

;c i od O

^

o; o

^ , ,

vD .

o; o

c ea .-^ U 6 0

Cd Eb

o

u ea u ? r 2 a

'So c o. E P.

X

c ea u ^ T 3

r 2 O

^^^ 61) C

pli

E

tra

z vo

X ed

E a cu

ca eo

' I ea 2 o

VI B CJ

B ^ N

OD

£ N CQ U

a

ed

ed

X ed

ffi u ^.

>o rv)

>o

^ d

o

§ ^ o

41

41

o vq lO

<o CN

41

O 00

8 § vo 41

g ^ ^ ? 41 lO

o o o

o ro

41

41

Ov

d 41

rv) rv)

41

Ov 00

o 2 o ~ ^ 41

00 o vd 41

ro ro

r o ro

O

ro ro CN

41

O rv) O "O d rvi — 41

r o od 41

o o

O r o O >o d — — 41

^ §0 ro . o; o

ro r~ ro VD d d — 41

ro 00 ro 00 d d — 41

VO

O ro O "O d — — 41

<o p~ O v

ro r o ro r o d — — 41

VD CJv

r o r o d 41

o; ^

ro ro ov

VO

r o r o OS

vq

41

p- ro vD ro — d — 41

<o

od

<o ro

rv) OS

O O

41

ON c^ as

em ^

"5. <" = = B i*

o S rv)

ov

O fN

41

VD

41

p -t. p- —

41

O 41

O o

o o

rv) fN

41

O vo

o fN P^

O rv)

41

41

O rv)

o rv)

rv) o

41

lO 00

o 00

VD VD

d 41

o

vd

vo .

o

>o

>o r o

O

>o

o r^ lO

<o rv)

Os

fN

ov

rv) C3V

Cd a u ed

U-) CN

>o <3v

O 00

>o VD

O r o

C ea , U 60

2 .£ _ N ea eb

O

Cd

B O

T3 ii Vi ed

X ii u ed Vi E O

'ei a

a B O CJ

•O B ed OJ

O O O CN

B

P.

a OH

fi

"ed B cd

£ o ii >

i u (U u

(U

Vi

• f i 3

T3 U Cl.

.B" "cj

I B O B

"ed

(LT u a ii u

flj

H

Tf 4-» ed ii

a ed B ii

3, o o ed a

X O

B 3

-O ii

o. Cl.

B

o B

CN

" 3 Vi ii

O t ii u OJ

(U C/3

X)

S o

101

^

^

PERMISSION TO COPY

In presenting this thesis in partial fulfillment of the requirements for a master's

degree at Texas Tech University or Texas Tech University Health Sciences Center, I

agree that the Library and my major department shall make it freely available for

research purposes. Permission to copy this thesis for scholarly purposes may be

granted by the Director of the Library or my major professor. It is understood that

any copying or publication of this thesis for financial gain shall not be allowed

v^thout my further written permission and that any user may be hable for copyright

infringement.

Agree (Permission is granted.)

Student Sijmture < ^ Date /o/i^/co

Disagree (Permission is not granted.)

Student Signature Date

EFFECTS OF GRAZING AND TRAMPLING BY ROCKY MOUNTAIN ELK (Cervus elaphus nelsoni) ON THE VEGETATIVE...

Documents

Transcript of EFFECTS OF GRAZING AND TRAMPLING BY ROCKY MOUNTAIN ELK (Cervus elaphus nelsoni) ON THE VEGETATIVE...