United States Department of Agriculture / Forest Service

Rocky Mountain Research Station

General Technical Report RMRS-GTR-258

August 2011

Geomorphology, Hydrology, and Ecology of 

Great Basin Meadow Complexes—Implications 

for Management and Restoration
You may order additional copies of this publication by sending your 

mailing information in label form through one of the following media. 

Please specify the publication title and series number.

Publishing Services

Telephone (970) 498-1392

FAX (970) 498-1122

E-mail rschneider@fs.fed.us

Website http://www.fs.fed.us/rm/publications

Mailing address Publications Distribution

Rocky Mountain Research Station

240 West Prospect Road

Fort Collins, CO 80526

Chambers, Jeanne C.; Miller, Jerry R., eds. 2011. Geomorphology, hydrology, and 

ecology of Great Basin meadow complexes—implications for management and 

restoration. Gen. Tech. Rep. RMRS-GTR-258. Fort Collins, CO: U.S. Department 

of Agriculture, Forest Service, Rocky Mountain Research Station. 125 p.

Abstract

This report contains the results of a 6-year project conducted by the U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research Station and 

U.S. Environmental Protection Agency, Office of Research and Development on 

stream incision and meadow ecosystem degradation in the central Great Basin. 

The project included a coarse-scale assessment of 56 different meadows systems 

coupled with more detailed, fine-scale analyses of six of those meadows. This 

report presents basic information on the linked geomorphic, hydrologic, and 

vegetation characteristics of the meadow systems. Then, the causes of degradation; 

the underlying geomorphic, hydrologic, and biotic processes operating within 

the meadows; and the factors required to evaluate the sensitivity or, conversely, 

resistance of streams and their associated meadow complexes to stream incision 

are described. Finally, management and treatment options are provided based on 

our current understanding of both the causes of degradation and the underlying 

processes.

Keywords: riparian areas, wetlands, semi-arid ecosystems, degradation, stream 

incision, stabilization

Editors

Jeanne C. Chambers is a Research Ecologist with the U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Research Station in Reno, Nevada, and 

an Adjunct Professor at the University of Nevada, Reno. Her primary research focus 

is on the restoration of disturbed or degraded ecosystems in the western United 

States. She served as the Team Leader of the Great Basin Ecosystem Management 

Project for Restoring and Maintaining Sustainable Riparian Ecosystems from 1993 

until its completion in 2009.

Jerry R. Miller holds the Blanton J. Whitmire Distinguished Professorship of 

Environmental Sciences at Western Carolina University. He has worked extensively 

in the United States and South America on the geomorphic responses of river 

systems to natural and anthropogenic disturbance and is coauthor of the third and 

fourth editions of the textbook Process Geomorphology (McGraw-Hill).

Cover photo: View of three Kingston Canyon meadows taken from Big Creek Peak. 

Photo by Mark Lord.
Acknowledgments

Financial and technical support for this project was provided by the U.S. 

Environmental Protection Agency and U.S. Department of Agriculture, Forest 

Service, Rocky Mountain Research Station. The U.S. Department of Agriculture, 

Humboldt-Toiyabe National Forest provided logistic support and funded the stream 

stabilization project in Kingston Canyon.

Kate Dwire, Dave Weixelman, Peter Weisberg, Sharon Lawlor, John Sandberg, 

Scott Baggett, and Erin Goergen provided review comments.

Authors

Jeanne C. Chambers

U.S. Department of Agriculture, Forest Service

Rocky Mountain Research Station

Reno, Nevada

jchambers@fs.fed.us

Sudeep Chandra

Department of Natural Resources and Environmental Science

University of Nevada, Reno

sudeep@cabnr.unr.edu

Tom Dudley

Marine Science Institute, University of California at Santa Barbara

tdudley@msi.ucsb.edu

Dru Germanoski

Department of Geology and Environmental Sciences

Lafayette College

Lafayette, Pennsylvania

germanod@lafayette.edu

Chris A. Jannusch

Department of Natural Resources and Environmental Science

 University of Nevada, Reno

cjannusch@ucdavis.alumni.com

David G. Jewett

U.S. Environmental Protection Agency

Office of Research and Development

Ada, Oklahoma

Jewett.david@epamail.epa.gov

Mark L. Lord

Department of Geosciences and Natural Resources

Western Carolina University

Cullowhee, North Carolina

mlord@wcu.edu

Jerry R. Miller

Department of Geosciences and Natural Resources

Western Carolina University

Cullowhee, North Carolina

jmiller@wcu.edu

Wendy Trowbridge

Department of Natural Resources and Environmental Science

University of Nevada, Reno

wtrowbridge@cabnr.unr.edu
ii

Contents

Chapter 1: Introduction and Overview.................................................................. 1

Jeanne C. Chambers, Jerry R. Miller, and Dru Germanoski

The Problem—Stream Incision and Meadow Degradation ..................................................... 1

Geological, Geographical, and Hydrologic Setting ................................................................ 1

Causes of Degradation—Climate Change and Other Natural and 

Anthropogenic Disturbance............................................................................................... 5

Processes That Influence Stream Incision and Meadow Ecosystems ....................................... 5

Conceptual Basis for Restoration and Management................................................................ 6

Objectives and Contents of This Report ................................................................................. 8

References............................................................................................................................. 8

Chapter 2: Controls on Meadow Distribution and Characteristics................... 11

Dru Germanoski, Jerry R. Miller, and Mark L. Lord

Introduction..........................................................................................................................11

Factors Affecting Meadow Distribution and Development ....................................................11

Summary ............................................................................................................................. 22

References........................................................................................................................... 23

Chapter 3: Geomorphic Processes Affecting Meadow Ecosystems .................. 24

Jerry R. Miller, Dru Germanoski, and Mark L. Lord

Introduction......................................................................................................................... 24

Channel and Valley Incision ................................................................................................ 24

Channel Avulsion................................................................................................................. 38

Summary ............................................................................................................................. 39

References........................................................................................................................... 43

Chapter 4: Hydrologic Processes Influencing Meadow Ecosystems.................. 44

Mark L. Lord, David G. Jewett, Jerry R. Miller, Dru Germanoski, and Jeanne C. Chambers

Introduction......................................................................................................................... 44

Hydrologic Characteristics and Processes ............................................................................ 44

Approach for Assessing the Hydrologic Status of Meadows.................................................. 62

Summary of Meadow Hydrologic Processes and Properties ................................................. 63

References........................................................................................................................... 66

Chapter 5: Meadow Sensitivity to Natural and Anthropogenic Disturbance... 68

Jerry R. Miller, Mark L. Lord, and Dru Germanoski

Introduction......................................................................................................................... 68

Geomorphic Sensitivity........................................................................................................ 68

Hydrologic Sensitivity.......................................................................................................... 75

Hydrologic Processes and the Factors Controlling Sensitivity ............................................... 76

References........................................................................................................................... 83
iii

Chapter 6: Meadow-Stream Processes and Aquatic Invertebrate 

Community Structure ........................................................................................... 85

Chris A. Jannusch, Sudeep Chandra, Tom Dudley, Jeanne C. Chambers, 

and Wendy Trowbridge

Introduction......................................................................................................................... 85

Methods............................................................................................................................... 85

Results................................................................................................................................. 87

Discussion ........................................................................................................................... 89

Management Summary ........................................................................................................ 93

References........................................................................................................................... 94

Chapter 7: Charcterization of Meadow Ecosystems Based on 

Watershed and Valley Segment/Reach Scale Characteristics ........................... 95

Wendy Trowbridge, Jeanne C. Chambers, Dru Germanoski, Mark L. Lord, 

Jerry R. Miller, and David G. Jewett

Introduction......................................................................................................................... 95

Description of Study Meadows ............................................................................................ 95

Methods............................................................................................................................... 96

Results and Discussion......................................................................................................... 97

Management Summary ...................................................................................................... 106

References......................................................................................................................... 106

Chapter 8: Meadow Management and Treatment Options ............................. 113

Jeanne C. Chambers and Jerry R. Miller

Introduction........................................................................................................................113

Prioritizing Meadow Management ......................................................................................113

Objectives and Design Criteria for Stream Stabilization and Meadow 

Vegetation Management .................................................................................................114

Identification and Selection of Treatment Options...............................................................114

General Considerations for Stream Stabilization..................................................................115

In-Stream Structures and Aquatic Habitat Enhancement Devices ........................................116

General Considerations for Vegetation Management...........................................................119

Use of Vegetation Management ......................................................................................... 121

Other Management Considerations.................................................................................... 123

Post-Project Evaluation, Monitoring and Adaptive Management ........................................ 123

References......................................................................................................................... 124
Figure 1.1. Map of the floristic Great Basin, outlined in white with the study area inset.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 1

The Problem—Stream Incision and 

Meadow Degradation

Streams and riparian ecosystems are a particularly valuable resource in the arid to semi-arid Great Basin, 

supplying water for agriculture and domestic uses, forage 

for livestock, and habitat for diverse aquatic and terrestrial 

organisms. In upland watersheds of the central Great Basin, 

many of the streams and riparian ecosystems have been severely degraded (Chambers and Miller 2004b; Chambers 

and others 2004a). A primary cause of this degradation is 

ongoing stream incision (downcutting) that occurs during 

episodic high flow events (Miller and others 2001, 2004). 

Meadow complexes (areas with shallow water tables that are 

dominated largely by grasses and carices) are at especially 

high risk of degradation because they often occur in hydrologic and geomorphic settings that are susceptible to stream 

incision (Chambers and others 2004a, 2004b; Germanoski 

and Miller 2004; Jewett and others 2004). In many cases, 

streams have been isolated from their original floodplains, 

and there have been significant changes in channel pattern and form. As the channels have incised, the base level 

for groundwater discharge has been lowered, resulting in 

deeper water tables. Because riparian vegetation depends 

on groundwater availability, there have been changes in the 

structure and composition of meadow ecosystems (Wright 

and Chambers 2002; Chambers and others 2004a, 2004b). 

The net effect has been a decrease in the aerial extent of the 

riparian corridor and a loss of meadow ecosystems.

In this chapter, we briefly review the major causes of, and 

controls on, channel incision and meadow degradation in the 

central Great Basin and discuss a conceptual basis for meadow restoration and management. In subsequent chapters, we 

focus on our current understanding of meadow ecosystems 

and the development of management strategies. We begin 

with an overview of the geologic, climatic, and hydrologic 

setting of the central Great Basin.

Geological, Geographical, and 

Hydrologic Setting

Great Basin Physiography

The hydrologic Great Basin encompasses an area of over 

500,000 km2 and includes most of the state of Nevada and 

portions of California, Oregon, Idaho, Utah, and Arizona (fig. 

1.1). Despite rugged topography and prominent topographic 

relief, the region has no significant external surface drainage (Mifflin 1988). The Great Basin is part of the Basin and 

Range physiographic province that consists of over 400 discrete mountain ranges that are separated by intermontane 

basins (Dohrenwend 1987). The mountain ranges and basins are oriented in a north-south direction, vary in length 

from tens to hundreds of kilometers and are typically 15 to 

25 km wide (fig. 1.2; Dohrenwend 1987). Basin elevations 

are about 1300 to 1600 m above sea level, while mountain 

ranges have elevations that exceed 3500 m (Stewart 1978).

The topography of the Basin and Range was produced 

by regional ongoing uplift and extensional tectonism that 

began in the Miocene (approximately 17 million years before present [BP]) (Stewart 1978; Thatcher and others 1999). 

Horizontal extension produced horst and graben structures. 

Horsts are up-thrown blocks of crustal material that are 

bounded by normal faults on either side. Basin-forming 

grabens are down-dropped crustal blocks, again bound by 

normal faults. Mountain ranges and basins also are formed 

by extension-driven rotation of crustal blocks (Stewart 

1978). The high relief between mountain ranges and adjacent basins produces steep potential energy gradients that 

drive stream incision in the mountains and sediment transfer to the intermontane basins. As a result, the mountains 

are deeply incised, and mountain fronts are fringed by coalescing alluvial fans that grade into basin-fill alluvium and 

lacustrine deposits (fig. 1.3).

Great Basin Geology

Lithology and Structure. Bedrock within the Great Basin 

of central Nevada ranges from Late Precambrian to Tertiary 

in age and is composed of the full spectrum of rock types, including intrusive (plutonic) and extrusive (volcanic) igneous 

rocks, chemical and clastic sedimentary rocks and metamorphic rocks. From Late Precambrian through the Paleozoic, 

the area that is now the Great Basin consisted of a continental margin that was characterized by deposition of sediment 

from the western continental landscape. Clastic (primarily 

shale and sandstone) and chemical (primarily limestone) 

sedimentary rocks were produced in a marine sedimentary 

basin throughout the Paleozoic (Stewart 1978). The continental margin evolved into an active subduction zone that 

produced igneous plutons that intruded and metamorphosed 

the Paleozoic sedimentary rocks and generated explosive 

volcanic eruptions that mantled the landscape with ashflow 

tuffs, ignimbrites, rhyolite flows and, later, localized basaltic 

lavas.

Chapter 1: Introduction and Overview

Jeanne C. Chambers, Jerry R. Miller, and Dru Germanoski
2 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Figure 1.2. Digital elevation map for the Great 

Basin. White rectangle in top center reflects 

a gap in the elevation data. Map based on 

U.S. Geological Survey data files.

Figure 1.3. Alfalfa fields at the base of the alluvial apron on the east side of the Toiyabe Range that are 

irrigated by shallow groundwater.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 3

The Lower Paleozoic units in the study area consist of 

sedimentary, low-grade metamorphic and volcanogenic 

rocks. In the northern portion of the study area, two distinct 

groups of Lower Paleozoic rocks are present: (1) a carbonate assemblage with minor shale and quartzite, and (2) an 

assemblage that consists of siliceous chert-rich sedimentary rocks, volcanic flows, and pyroclastic rocks (Stewart 

and McKee 1977). The siliceous rocks were deposited in 

the western portion of the depositional basin and then thrust 

over the carbonate rocks during the Antler Orogeny (Stewart 

and McKee 1977). In the southern portion of the study area, 

siliciclastics, including sandstones, siltstones, and shales, 

are more common than carbonates and have been metamorphosed to quartzites, phyllitic schists, phyllite, and slate 

(Kleinhampl and Ziony 1985).

During the Late Paleozoic, clastic sediment that was derived from the Antler orogenic belt was deposited across the 

deformed lower Paleozoic rocks. Pyroclastic volcanic rocks 

and clastic sedimentary rocks that were deposited in a marine 

back-arc basin to the west were subsequently thrust eastward 

during the Permian along the Golconda Fault over the coarse 

clastic units (Stewart and McKee 1977). Thus, Paleozoic 

rocks consist of a complex assemblage of rock types deposited in diverse depositional settings and thrust faulted and 

deformed during the Late Paleozoic Antler Orogeny.

The Paleozoic rocks were intruded by igneous plutons 

during the Mesozoic (primarily the Jurassic and Cretaceous), 

including the Austin pluton, which is the largest in the region. 

The Austin pluton is exposed at the surface in three areas 

near Austin in the Toiyabe Range. Petrologic characteristics 

suggest that the three exposures are part of a single large 

batholith that is separated by inliers of Paleozoic sedimentary rocks (Stewart and McKee 1977). The intrusive rocks 

primarily range from quartz monzonites to granodiorites in 

composition and are characterized by a platy sheet structure 

that makes some of the large plutons appear to be bedded 

(Stewart and McKee 1977).

Cenozoic age rocks are dominated by volcanic materials following the emplacement of scattered intrusive quartz 

monzonite and quartz diorite plutons in the Late Eocene to 

Early Miocene. The earliest phase of Tertiary volcanism was 

dominated by andesitic and dacitic lavas that were extruded 

during the early Oligocene. These extrusions were followed 

by a shift to rhyolite and quartz-latite ash-flow tuffs in the 

late Oligocene. These rocks are capped by Miocene and 

Pliocene volcanics that range in composition from andesite to basalt with basaltic eruptions occurring into the 

Pleistocene (Stewart and McKee 1977).

Paleozoic rocks were folded, metamorphosed, and cut 

by low angle thrust faults from west to east during the Late 

Paleozoic Antler and Sonoma Orogenies and, to a lesser extent, during the Mesozoic Laramide Orogeny. Recent work 

in the Toiyabe Range in the center of the study area (fig. 1.1) 

indicates that the structural history of the Basin and Range 

is more complex than previously recognized and that there 

were elements of structural extension and transpression in 

the Late Paleozoic that produced normal faults perpendicular and tangential to the Toiyabe Range (Smith and Miller 

1990). In the Miocene, the tectonic regime changed from 

compressional to an extensional regime that led to episodes 

of uplift and crustal extension that were responsible for development of the modern topography.

River incision into rising, fault-bounded horsts and rotationally uplifted mountain ranges coevolved with uplift 

and both processes continued throughout the Cenozoic. As a 

result, mountain uplands are deeply dissected by rivers that 

drain both east and west from the axis of each range into 

intermontane basins. Although the mountains are erosional 

landscapes with streams that flow directly on bedrock in 

many locations, valleys are locally floored by Holocene age 

alluvium to depths exceeding 50 m. Axial valley-fill sediment interfingers with alluvial fan sediment from side-valley 

tributaries. In many cases, fans prograde into the axial valleys as pronounced landforms. Hillslopes are mantled locally 

with a thin veneer of alluvium with scree chutes formed in 

zero-order tributaries. Soils are typically thin and poorly developed owing to the arid climate, steep slopes, and erosion.

Great Basin Hydrology

Distribution of Precipitation and Evapotranspiration.

The Great Basin is a semi-arid to arid region. Average annual precipitation varies from less than 150 to approximately 

700 mm/yr (6 to 27.5 inches/yr; fig. 1.4) with the majority 

of the precipitation falling as snow during winter months. 

Precipitation varies significantly between individual mountain ranges and intervening basins and from mountain range 

to mountain range due to orographic effects (Mifflin 1988). 

The highest precipitation occurs in higher, broader mountain 

ranges because of the ability of high mountains to influence 

moist air masses moving across the basin from west to east.

In the Great Basin, evaporation potential exceeds annual 

precipitation because of the combination of low precipitation and high average temperatures. Similar to the spatial 

distribution of precipitation, the evaporation potential varies 

from range to range and between a mountain range and its 

adjacent basins. However, the trends are opposite of precipitation patterns; average annual temperature and evaporation 

potential is higher in intermontane basins than in mountain 

ranges, and annual average temperature varies inversely 

with elevation in the mountains. Therefore, the water supply 

is decidedly asymmetric with mountains serving as water 

sources and basins serving as “sinks.”

Major Rivers and Mountain Streams. The Basin and 

Range topography exerts tremendous control on the regional 

hydrology (fig. 1.5). The down-dropped grabens and intermontane basins create regionally significant depressions that 

capture surface water drainage for hundreds of square kilometers. In the most extreme case, basin elevation extends 

below sea level in Death Valley in the southwestern portion 

of the Basin and Range. Thus, the Great Basin is a unique 

region in North America because all major rivers in the region drain into lakes or sinks in intermontane basins, and no 

major rivers leave the region and drain to the ocean.

The longest river in the Great Basin is the Humboldt River, 

which drains from east to west across northern Nevada from 
4 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

its headwaters in the East Humboldt Range, through Rye 

Patch Reservoir, to its terminus at Humboldt sink almost 

500 km away. The Reese River rises in the study area in the 

southern portion of the Toiyabe Range and flows north to its 

junction with the Humboldt River at Battle Mountain. It is 

the second longest river in Nevada but, despite its regional 

prominence, the Reese River is intermittent and consists of 

alternating gaining and losing reaches. In fact, along many 

segments the valley floor lacks well-defined surface channels, and down-valley flow of water primarily occurs in the 

subsurface. The Reese River has flowed as a continuous surface water body from head to mouth only three times in the 

Twentieth Century. Other major rivers in the Great Basin are 

the Carson River, which drains into Carson Sink, and the 

Truckee River, which rises in the eastern Sierra and drains 

into Pyramid Lake. Many intermontane basins in the region 

do not have major streams or rivers and instead are occupied 

by playa lakes that capture all of the local drainage from the 

surrounding mountains.

The highest density of surface water streams occurs in 

the mountains because most precipitation in the region falls 

in the mountains, where evapotranspiration is relatively low. 

Mountain streams are fed by rainfall, snowmelt, and springs 

that are distributed throughout the drainage basins particularly at mid to high elevations.

Discharge from mountain watersheds varies with 

drainage basin area, local mean annual precipitation, and 

percentage of the drainage basin that is at high altitude (Hess 

2002). Because evapotranspiration potential increases from 

mountains to intermontane basins and because alluvial fan 

sediments at mountain fronts tend to be thick and permeable, most mountain streams are rarely integrated with the 

intermontane basin drainage system. Most of the time a 

significant percentage of water that is delivered to the mountain front from small mountain streams infiltrates into the 

alluvial-fill sediments. High evapotranspiration rates further 

deplete this surface water discharge as streams transition 

form cooler, more shaded confines of mountain valleys 

onto the apex of the mountain-front alluvial fans (fig. 1.3). 

Large watersheds that drain higher mountain systems like 

Big Creek and Kingston Canyon in the Toiyabe Range and 

Barley Creek in the Monitor Range are able to collect sufficient discharge to flow into the axes of intermontane basins 

more frequently. Surface water drainage networks are typically integrated as continuous surface water flow systems 

with a frequency of about several times per century under 

the current climatic regime. However, mountain watersheds 

may feed playa lakes and master drainage networks far out 

into the main basins as subsurface groundwater flow.

Figure 1.4. Average annual precipitation for the State of 

Nevada.

Figure 1.5. River systems in the hydrologic Great Basin of Nevada.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 5

Causes of Degradation—Climate 

Change and Other Natural and 

Anthropogenic Disturbance

The causes of degradation of riparian corridors and meadow complexes in the central Great Basin are the result of 

complex and interrelated responses of geomorphic, hydrologic, and vegetation processes to natural and anthropogenic 

disturbances as well as changes in climate. Anthropogenic 

disturbances include all human activities that affect physical and biological processes within a watershed, and natural 

disturbances include phenomena such as floods, landslides, 

and wildfires. Climate change operates over longer temporal scales and larger spatial scales than natural disturbances 

and exerts a major control on watershed processes in arid and 

semi-arid ecosystems. Restoration and management activities 

must therefore take into account the significant effects of both 

past and present climate on geomorphic and fluvial processes 

in the Great Basin and, consequently, on riparian and aquatic 

ecosystems. In upland watersheds of the central Great Basin, 

climate-driven changes in hillslope and fluvial processes that 

occurred during the mid-to-late Holocene still influence the 

composition and pattern of riparian ecosystems over a broad 

range of scales (Miller and others 2001, 2004; Chambers and 

others 2004a). Paleoecological and stratigraphic data collected in the central Great Basin indicate that a major drought 

occurred in the Region from approximately 2580 to 1900 

years BP (Miller and others 2001; Tausch and others 2004). 

During this drought, most of the available fine-grained sediments were stripped from hillslopes and deposited on valley 

floors and side-valley alluvial fans (Miller and others 2001, 

2004). As a consequence of this hillslope erosion, streams are 

currently sediment limited and exhibit a natural tendency to 

incise. Available geomorphic data indicate that over the past 

2000 years, the dominant response of streams to both natural 

and anthropogenic disturbance has been incision. The most 

recent episode of incision began about 450 years BP before 

Anglo-American settlement of the region in 1860. However, 

incision has been more intense and pervasive during the past 

150 years. Most of this recent incision occurs during episodic, high flow events that are highly variable both among 

and within years in these semi-arid ecosystems. In recent 

decades, high flow events capable of producing significant 

incision occurred in the mid-1970s, 1983, 1995, 1998, and 

2005 due to high precipitation and rapid runoff (Chambers 

and others 1998; Germanoski and others 2001).

The rate and magnitude of steam incision in central Great 

Basin watersheds have been increased by anthropogenic 

disturbances. Roads that are located in valley bottoms are 

perhaps the major human-related cause of recent stream incision and riparian area degradation in the central Great Basin. 

The effects of roads on stream systems have been clearly 

documented for other locations (USDA Forest Service 1997; 

Jones and others 2000; Trombulak and Frissel 2000). In the 

central Great Basin, several cases of “road captures” have 

been documented and many other cases have been observed 

where streams were diverted onto road surfaces during high 

flows (Lahde 2003). These diversions result in increased 

shear stress and stream power and, ultimately, localized 

stream incision (Lahde 2003). Once initiated, knickpoint 

migration often results in stream incision along the channel.

There is no direct evidence linking regional stream incision to overgrazing by livestock in the central Great Basin, 

but overgrazing has undoubtedly had localized effects on 

stream channels. Effects similar to those for road captures 

have been documented for livestock trails elsewhere in the 

western United States (Trimble and Mendel 1995) and likely 

occur for off-road vehicle trails. Also, overgrazing by livestock has been shown to negatively affect stream bank and 

channel stability and often has been associated with localized 

changes in stream morphology (see reviews in Trimble and 

Mendel 1995; Belsky and others 1999; National Research 

Council 2002). Generalized effects of overgrazing by livestock on riparian ecosystems include undesirable changes 

in species composition and structure, soil properties, biogeochemical cycling, and water quality. These effects are 

well documented elsewhere (see reviews in Kauffman and 

Krueger 1984; Skovlin 1984; Clary and Webster 1989; 

National Research Council 1992, 2002; Fleischner 1994; 

Ohmart 1996; Belsky and others 1999).

Processes That Influence Stream 

Incision and Meadow Ecosystems

Stream and restoration ecologists have recognized for some 

time that effective management and restoration approaches 

must not only address the appropriate scales but also must be 

process based (Frissell and others 1986; Goodwin and others 

1997). Recent research in the central Great Basin illustrates 

the close linkages among watershed, valley segment, and 

reach-level controls and geomorphic, hydrologic, and vegetation processes (Lord and others 2009). Watersheds differ 

in sensitivity to both natural and anthropogenic disturbance 

and, thus, in the likelihood of stream incision (Germanoski 

and Miller 2004). Ecologists use the terms “resistance” and 

“resilience” to evaluate the sensitivity of ecosystems to disturbance. Resistance refers to the ability of an ecosystem to 

maintain characteristic processes despite various stressors 

or disturbances, while resilience refers to the capacity to 

regain the same processes over time following stress or disturbance (Society for Ecological Restoration International 

2002). Major disturbances can result in threshold crossings and new ecological states characterized by different 

ecological processes. Similarly, geomorphologists describe 

the sensitivity of landforms to disturbance as the propensity 

for a change in the environment to result in a new equilibrium state (Schumm and Brackenridge 1987; Germanoski 

and Miller 2004). Watershed sensitivity to disturbance is 

influenced by factors such as the erosional resistance of 

the underlying bedrock and channel-forming materials and 

watershed relief, morphometry, and hydrology. In the central Great Basin, watershed sensitivity to disturbance and, 

thus, stream incision is related to watershed characteristics 

such as geology, size, relief, and morphometry and valley 
6 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

segment attributes such as gradient, width, and substrate size 

(Germanoski and Miller 2004). Watersheds that are highly 

sensitive to disturbance exhibit a greater response to more 

frequent, lower magnitude runoff events than watersheds 

that are less sensitive to disturbance.

The combined geomorphic and hydrologic characteristics of the watersheds determine the pattern and composition 

of riparian vegetation at watershed to valley segment scales 

(Chambers and others 2004a, 2004b). Thus, watershed, valley-segment, and stream reach attributes, such as those that 

characterize basin sensitivity to disturbance, also have good 

predictive value for riparian ecosystems, including the presence, characteristics, and ecological condition of meadow 

complexes. For example, flood-dominated watersheds that 

are characterized by tertiary volcanic rock, high-relief, narrow valleys, bedrock control, minimal sediment storage, and 

multiple discontinuous terraces rarely have the geomorphic 

or hydrologic conditions to support meadow ecosystems 

(Chambers and others 2004b; Germanoski and Miller 2004). 

In contrast, fan-dominated watersheds that are characterized 

by prominent side-valley alluvial fans or side-valley tributary 

deposits (graded fans) often have the geomorphic and hydrologic conditions necessary to support meadow complexes.

Watersheds with prominent side-valley alluvial fans have 

been well-studied in the central Great Basin (Germanoski and 

Miller 2004; Jewett and others 2004; Miller and others 2001, 

2004) and provide an excellent example of how watershed 

characteristics influence the occurrence of meadows and processes that cause meadow degradation over time. The most 

recent period of fan aggradation in the region occurred during 

the first half of the drought that occurred from about 2500 to 

1300 years BP. In some cases, the fans extended across the 

entire width of the valley floor and impinged on opposing 

hillslopes, blocking down-valley transport of water and sediment along the axial stream channel. Significant quantities of 

sediment were deposited upstream of these fans, resulting in 

a reduction in valley floor gradient and an increase in valley 

floor width. The toes of the fans were subsequently breached, 

and fan sediments were carried down valley, causing several 

meters of aggradation along the riparian corridor. Today, watersheds with well-developed fans often are characterized 

by stepped-valley profiles and riparian corridors that exhibit 

abrupt changes in local geomorphic, hydrologic, and vegetation attributes. Meadow ecosystems typically occur upstream 

of side-valley alluvial fans where necessary conditions (bedrock highs, finer textured sediments, and/or springs) exist to 

maintain shallow water tables. Woody vegetation (willows, 

rose, aspen, and cottonwood) typically occurs at the fan 

and above the meadow complex. Many fans serve as local 

base-level controls that determine the rate and magnitude of 

upstream incision. These fans are subject to stream incision 

due to high shear stress associated with high flow events. 

Consequently, meadow ecosystems that are located immediately upstream of alluvial fans often are at risk of degradation 

due to stream incision through fan deposits.

Regardless of the watershed characteristics and cause 

of disturbance, stream incision lowers the base level for 

groundwater discharge and may result in deeper water 

tables. Meadow complexes occur along hydrologic gradients (Weixelman and others 1996; Castelli and others 2000) 

that are influenced by the rates and magnitudes of incision 

along the axial channels and development and entrenchment 

of surface channels within meadows (Wright and Chambers 

2002; Chambers and others 2004a, 2004b; Jewett and others 

2004). At one end of the hydrologic gradient, wet meadow 

ecological types exist with water tables at or near the ground 

surface and limited, shallow, and discontinuous surface 

channels. Prior to incision, shallow overland flow typically predominates during spring snowmelt and periods of 

high runoff. At the other end of the hydrologic gradient, dry 

meadow and sagebrush ecological types exist that have water tables from 150 to 250 cm below the ground surface and 

that seldom experience overland flows. As stream incision 

progresses and water tables drop, wetter meadow ecological 

types are progressively converted to drier meadow types. In 

the worst case scenario, the hydrologic regime and riparian 

vegetation are so severely affected that meadow complexes 

are replaced by drier plant communities that are dominated 

by sagebrush and wetter meadow plant communities exist 

only within the stratigraphic record.

Conceptual Basis for Restoration 

and Management

Restoring and maintaining riparian ecosystems in the 

Great Basin is a management priority but has proven difficult because of ongoing and widespread stream incision 

and failure of standard stream stabilization measures such 

as livestock management or instream structures to prevent 

or reverse this degradation (Clary 1995; Kondolf 1995; 

Kaufman and others 1997; Clary and Kinney 2002; Wohl 

2004). Many streams and riparian ecosystems in upland 

watersheds of the central Great Basin are currently functioning as nonequilibrium systems due to depletion of hillslope 

sediments during the mid-to-late Holocene drought and the 

tendency for stream incision (Chambers and others 2004b; 

Germanoski and Miller 2004; Miller and others 2004). Some 

streams have adjusted to the current geomorphic conditions 

and have reached their maximum depth of incision under 

the current sediment and hydrologic regime. Others are still 

adjusting and will continue to incise because of channel heterogeneity and lack of hillslope sediments. In many cases, 

incised streams have crossed geomorphic thresholds and, 

because of the changes in stream processes and groundwater 

regimes, riparian ecosystems also have crossed thresholds. 

Threshold crossings occur when a system does not return to 

the original state following disturbance, and can be defined 

based on the limits of natural variability within systems 

(Ritter and others 1999).

For stream systems and riparian ecosystems in the central 

Great Basin that have crossed geomorphic and hydrologic 

thresholds, return to the predisturbance state is not an ecologically or economically viable goal. The restoration and 

management potential of a stream system or riparian ecosystem must be based on current, not historic, conditions. 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 7

Chambers and others (2004b) defined the goal of restoration 

and management activities as reestablishing and maintaining sustainable fluvial systems and riparian ecosystems that 

exhibit both characteristic processes and related biological, 

chemical, and physical linkages among system components 

(modified from Natural Research Council 1992). In this context, sustainable stream systems and riparian ecosystems 

exhibit natural variability, yet maintain characteristic processes, including rates and magnitudes of geomorphic activity, 

hydrologic flux and storage, biogeochemical cycling and 

storage, and biological activity and production (Christensen 

and others 1996; Wohl and others 2005). Sustainable ecosystems provide valuable ecosystem services, including high 

quality water, habitat for aquatic and terrestrial organisms, 

forage and browse, and recreational opportunities.

Reestablishing and maintaining riparian ecosystems in 

the central Great Basin and elsewhere requires an integrated 

and interdisciplinary approach that addresses the geomorphic, hydrologic and biological components of the system 

(Chambers and others 2004b; Wohl and others 2005). As 

illustrated above, and as has been advocated elsewhere, a 

critical first step is to develop an understanding of the causes 

of degradation and of the underlying physical and biotic 

processes (Goodwin and others 1997; Wissmar and Beschta 

1998; Wohl and others 2005). Once developed, this integrated understanding of riparian ecosystems can be used for 

prioritizing restoration and management activities and for 

determining appropriate techniques.

Developing the necessary understanding for effective 

management/restoration of riparian areas requires addressing appropriate spatial and temporal scales. A watershed 

can be viewed as a hierarchical system containing different 

spatial and temporal scales that are nested within one another (Schumm and Lichty 1965; Frissell and others 1986; 

Newbury and Gaboury 1993). Scales can range from an entire watershed (101

 to 106 years, km2) to individual events 

or particles (<10 years, <0.10 cm2). A watershed perspective and the historical evaluation of different scales provide 

a more complete understanding of riparian ecosystems and 

their interactions with the geomorphic and hydrologic regime (Wissmar and Beschta 1998). Scales that are addressed 

here are the watershed, riparian corridor, valley segment, 

and stream reach (fig. 1.6). The riparian corridor is the integrated network of stream channels and adjacent geomorphic 

Figure 1.6. Spatial scales of study.

Stream

Reach

Valley Segment

Watershed

Valley

Segment

Riparian Corridor
8 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

surfaces (in other words, floodplain and terraces) that are 

located primarily on alluvial deposits in valley bottoms. The 

riparian corridor receives water and sediment from surrounding hillslopes and represents a pivotal interface between 

surface and groundwater flow systems. Characteristics of 

watersheds and riparian corridors are often closely related to 

sensitivity of watersheds to disturbance, likelihood of stream 

incision (Germanoski and Miller 2004), and dominant vegetation types within the watershed (Chambers and others 

2004b). Nested within riparian corridors are valley segments that have semi-uniform valley characteristics (slopes, 

widths, and geologic materials) and similar climatic conditions. The smallest components in our hierarchy are stream 

reaches or sections of the valley segments with relatively 

uniform channel morphology, bed material composition, 

bank conditions, and woody debris. Characteristics of valley segments and stream reaches determine the geomorphic 

setting and hydrologic regime of riparian ecosystems and, 

thus, site-specific geomorphic, hydrologic, and vegetation 

processes that influence resistance and resilience of riparian ecosystems to high flow events and other perturbations 

(Chambers and others 2004b; Jewett and others 2004).

Objectives and Contents of 

This Report

In 1992, a USDA Forest Service, Rocky Mountain 

Research Station ecosystem management project on restoring and maintaining sustainable riparian ecosystems was 

initiated to address the problems associated with stream 

incision and riparian ecosystem degradation in the central 

Great Basin (see Chambers and Miller 2004b). A collaborative project was developed with the U.S. Environmental 

Protection Agency’s (USEPA) Office of Research and 

Development in 2002 to build on the results of the ecosystem management project and to develop management 

options for addressing the current effects of stream incision 

on meadow complexes. This report contains the results of 

the collaborative Forest Service and EPA project, which was 

based on a coarse-scale assessment of 56 individual meadow 

systems coupled with more detailed, fine-scale analyses of 

6 of those meadows (fig. 1.7). It provides the necessary understanding and tools to develop effective restoration and 

management programs for meadow complexes in the central 

Great Basin. The approach used by the collaborative project is reflected in the report’s contents. First, the causes of 

degradation and underlying geomorphic, hydrologic, and 

biotic processes operating within the meadows are examined. Then, we examine the factors required to evaluate the 

sensitivity or, conversely, resistance of streams and their 

associated meadow complexes to stream incision. Finally, 

management and treatment options are developed based on 

an understanding of both the causes of degradation and the 

underlying processes. The specific components of this report 

are as follows:

• An understanding of the geomorphic and hydrologic 

controls on Great Basin meadow complexes;

• An understanding of the geomorphic, hydrologic, and 

vegetation processes that affect watershed and meadow 

sustainability;

• Information on the factors needed to evaluate sensitivity 

to disturbance for both watersheds and meadow 

complexes;

• Information on the value of biodiversity indicators for 

aquatic and terrestrial macro-invertebrates for evaluating 

restoration outcomes and ecological conditions of 

meadows and their associated stream systems;

• A characterization of meadow complexes that exist 

within central Great Basin watersheds based on 

watershed and valley segment/reach-scale attributes; and

• Methods for maintaining or restoring the stream systems 

and vegetation communities associated with riparian 

meadows.

References

Belsky, A.J.; Matzke, A.; Uselman, S. 1999. Survey of livestock 

influences on stream and riparian ecosystems in the western 

United States. Journal of Soil and Water Conservation. 51: 

419-431.

Castelli, R.M.; Chambers, J.C.; Tausch, R.J. 2000. Soil-plant 

relations along a soil-water gradient in Great Basin riparian 

meadows. Wetlands. 20: 251-266.

Chambers, J.C.; Farleigh, K.; Tausch, R.J.; Miller, J.R.; Germanoski, 

D.; Martin, D.; Nowak, C. 1998. Understanding long- and shortterm changes in vegetation and geomorphic processes: the key to 

riparian restoration. In: Potts, D.F., ed. Rangeland management 

and water resources. Herndon, VA: American Water Resources 

Association and Society for Range Management: 101-110.

Chambers, J.C.; Miller, J.R. eds. 2004a. Great Basin Riparian 

Ecosystems—Ecology, Management and Restoration. Covelo, 

CA: Island Press. 303 p.

Chambers, J.C.; Miller, J.R. 2004b. Restoring and maintaining 

sustainable riparian ecosystems–the Great Basin Ecosystem 

Management Project. In: Chambers, J.C.; Miller, J.R., eds. 

Great Basin Riparian Ecosystems—Ecology, Management, and 

Restoration. Covelo, CA: Island Press: 1-24.

Chambers, J.C.; Miller, J.R.; Germanoski, D.; Weixelman, D.A. 

2004a. Process based approaches for managing and restoring 

riparian ecosystems. In: Chambers, J.C.; Miller, J.R., eds. 

Great Basin Riparian Ecosystems—Ecology, Management, and 

Restoration. Covelo, CA: Island Press: 261-292.

Chambers, J.C.; Tausch, R.J.; Korfmacher, J.L.; Miller, J.R.; Jewett, 

D.G. 2004b. Effects of geomorphic processes and hydrologic 

regimes on riparian vegetation. In: Chambers, J.C.; Miller, J.R., 

eds. Great Basin Riparian Ecosystems—Ecology, Management, 

and Restoration. Covelo, CA: Island Press: 196-231.

Clary, W.P.; Webster, B.F. 1989. Managing grazing of riparian areas in 

the Intermountain Region. Gen. Tech. Rep. INT-263. Ogden, UT: 

U.S. Department of Agriculture, Forest Service, Intermountain 

Forest and Range Experiment Station. 11 p.

Clary, W.P. 1995. Vegetation and soil responses to grazing simulation 

on riparian meadows. Journal of Range Management. 48: 18-25.

Clary, W.P.; Kinney, J.W. 2002. Streambank and vegetation response 

to simulated cattle grazing. Wetlands. 22: 139-148.

Christensen, N.L.; Bartuska, A.M.; Brown, J.H.; Carpenter, S.; 

D’Antonio, C.; Francis, R.; Franklin, J.F.; MacMahon, J.A.; Noss, 

R.F.; Parsons, D.J.; Peterson, C.H.; Turner, M.G.; Woodmansee, 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 9

R.G. 1996. The report of the Ecological Society of America 

Committee on the scientific basis for ecosystem management. 

Ecological Applications. 6: 665-691.

Dohrenwend, J.C. 1987. Basin and Range. In: Graf, W.L., ed. 

Geomorphic Systems of North America: Boulder, CO: Geological 

Society of America, Centennial Special Volume 2: 303-342.

Fleischner, T.L. 1994. Ecological costs of livestock grazing in 

western North America. Conservation Biology. 8: 629-644.

Frissel, C.A.; Liss, W.J.; Warren, C.E.; Hurley, M.D. 1986. A 

hierarchical framework for stream habitat classification: viewing 

streams in a watershed context. Environmental Management. 10: 

199-214.

Germanoski, D.; Ryder, C.; Miller, J.R. 2001. Spatial variation 

of incision and deposition within a rapidly incised upland 

watershed, central Nevada. Proceedings of the 7th Interagency 

Sedimentation Conference; 25-29 March 2001; Reno, NV: 

Subcomittee on Sedimentation. v. 2: 141-148.

Germanoski, D.; Miller, J.R. 2004. Basin sensitivity to channel 

incision in response to natural and anthropogenic disturbance. 

In: Chambers, J.C.; Miller, J.R., eds. Great Basin Riparian 

Ecosystems—Ecology, Management, and Restoration. Covelo, 

CA: Island Press: 88-123.

Goodwin, C.N.; Hawkins, C.P.; Kershner, J.L. 1997. Riparian 

restoration in the western United States: overview and perspective. 

Restoration Ecology. 5: 4-14.

Figure 1.7. Locations of the meadow 

complexes evaluated by the project 

and discussed in this report. Land 

owernship designations: Forest 

Service = green; Bureau of Land 

Management = tan; Bureau of Indian 

Affairs = brown; nonfederal = white.
10 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Hess, G.W.; Bohman, L.R. 1996. Techniques for estimating monthly 

mean streamflow at gaged sites and monthly streamflow duration 

characteristics at ungaged sites in central Nevada. U.S. Geological 

Survey Open-File Report 96-559. 15 p.

Hess, G.W. 2002. Updated techniques for estimating monthly 

streamflow duration characteristics at ungaged and partial-record 

sites in central Nevada. U.S. Geological Survey Open-File Report 

02-168. 16 p.

Jewett, D.G.; Lord, M.; Miller, J.R.; Chambers, J.C. 2004. 

Geomorphic and hydrologic controls on surface and subsurface 

flow regimes in riparian meadow ecosystems. In: Chambers, J.C.; 

Miller, J.R., eds. Great Basin Riparian Ecosystems—Ecology, 

Management, and Restoration. Covelo, CA: Island Press: 

124-161.

Jones, J.A.; Swanson, F.J.; Wernpie, B.C.; Sjyder, K.U. 2000. Effects 

of roads on hydrology, geomorphology, and disturbance patches 

in stream networks. Conservation Biology. 14: 76-85.

Kauffman, J.B.; Krueger, W.C. 1984. Livestock impacts on riparian 

ecosystems and streamside management implications...a review. 

Journal of Range Management. 37: 430-438.

Kauffman, J.B.; Beschta, R.L.; Otting, N.; Lytjen, D. 1997. An 

ecological perspective of riparian and stream restoration in the 

western United States. Fisheries. 22: 12-24.

Kleinhampl, F.J.; Ziony, J.I. 1985. Geology of northern Nye County, 

Nevada. Nevada Bureau of Mines and Geology. Bulletin 99A. 

172 p.

Kondolf, G.M.; Larson, M. 1995. Historical channel analysis and 

its application to riparian and aquatic habitat restoration. Aquatic 

Conservation. 5: 108-126.

Lahde, D. 2003. The influence of secondary roads on stream incision 

in watersheds of the central Great Basin. Department of Natural 

Resources and Environmental Sciences, University of Nevada, 

Reno. Thesis. 106 p.

Meizer, O.E. 1916. Groundwater in Big Smoky Valley, Nevada. U.S. 

Geological Survey, Water Supply Paper 375: 85-116.

Lord, M.; Miller, J.; Germanoski, D.; Jewett, D.; Villarroel, L.; Tury, 

R.; Walsh, D.; Chambers, J. 2009. Do reach-scale geomorphically 

defined process zones predict sensitivity of channel systems and 

hydrologic processes in the mountains of the central Great Basin? 

Geological Society of America Abstracts with Programs. 41: 624.

Mifflin, M.D. 1988. Region 5, Great Basin. In: Back, W.; Rosenshein, 

J.S.; Seaber, P.R., eds. Hydrogeology: Boulder, CO: Geological 

Society of America, The Geology of North America. O-2: 69-86.

Miller, J.; Germanoski, D.; Waltman, K.; Tausch, R.; Chambers, 

J. 2001. Influence of late Holocene processes and landforms 

on modern channel dynamics in upland watersheds of central 

Nevada. Geomorphology. 38: 373-391.

Miller, J.R.; House, K.; Germanoski, D.; Tausch, R.J.; Chambers, 

J.C. 2004. Fluvial geomorphic responses to Holocene climate 

change. In: Chambers, J.C.; Miller, J.R., eds. Great Basin 

Riparian Ecosystems—Ecology, Management, and Restoration. 

Covelo, CA: Island Press: 49-87.

National Research Council. 1992. Restoration of aquatic ecosystems: 

science, technology, and public policy. Washington, DC: National 

Academy Press. 552 p.

National Research Council. 2002. Riparian areas: functions and 

strategies for management. Washington, DC: National Academy 

Press. 428 p.

Newbury, R.; Gaboury, M. 1993. Exploration and rehabilitation of 

hydraulic habitats in steams using principles of fluvial behaviour. 

Freshwater Biology. 29: 195-210.

Ohmart, R.D. 1996. Historical and present impacts of livestock 

grazing on fish and wildlife resources in western riparian habitats. 

In: Krausman, P.R., ed. Rangeland Wildlife. Denver, CO: Society 

for Range Management: 245-279.

Ritter, D.F.; Kochel, R.C.; Miller, J.R. 1999. The disruption of 

Grassy Creek: implications concerning catastrophic events and 

thresholds. Geomorphology. 29: 323-338.

Schumm, S.A.; Brackenridge, G.R. 1987. River response. In: 

Ruddiman, W.F.; Wright, H.E., Jr., eds. North America and 

adjacent oceans during the last deglaciation, the geology of 

North America, volume K-3. Boulder, CO: Geological Society 

of America: 221-240.

Schumm, S.A.; Lichty, R.W. 1965. Time, space, and causality in 

geomorphology. American Journal of Science. 263: 110-119.

Skovlin, J.M. 1984. Impacts of grazing on wetlands and riparian 

habitat: a review of our knowledge. In: National Research Council; 

National Academy of Sciences, corp. eds. Developing Strategies 

for Range Management. Society for Range Management. 

Boulder, CO: Westview Press: 1001-1103.

Smith, D.L. 1992. History and kinematics of Cenozoic extension in 

the northern Toiyabe Range, Lander County, Nevada. Geological 

Society of America Bulletin. 104: 789-801.

Smith, D.L.; Miller, E.L. 1990. Late Paleozoic Extension in the Great 

Basin, western United States. Geology.18: 712-715.

Society for Ecological Restoration International. 2002. The SERI 

Primer on Ecological Restoration. Science and Policy Working 

Group. Available: www.seri.org.

Stewart, J.H. 1978. Basin-range structure in western North America: 

a review. Geological Society of America Memoir. 152: 1-31.

Stewart, J.H.; McKee, E.H. 1977. Geology and mineral deposits of 

Lander County, Nevada. Part I Geology. Nevada Bureau of Mines 

and Geology. Bulletin 88.

Tausch, R.J.; Nowak, C.L.; Mensing, S.W. 2004. Climate change 

and associated vegetation dynamics during the Holocene: the 

paleoecological record. In: Chambers, J.C.; Miller, J.R., eds. 

Great Basin Riparian Ecosystems—Ecology, Management, and 

Restoration. Covelo, CA: Island Press: 24-48.

Thatcher, W.; Foulger, G.R.; Julian, B.R.; Svarc, J.; Quilty, E.; 

Bawden, G.W. 1999. Present-day deformation across the Basin 

and Range Province, western United States. Science. 283: 

1714-1718.

Trimble, S.W.; Mendel, A.C. 1995. The cow as a geomorphic 

agent—a critical review. Geomorphology. 13: 233-253.

Trombulak, S.C.; Frissell, C.A. 2000. Review of ecological effects 

of roads on terrestrial and aquatic communities. Conservation 

Biology. 14: 18-30.

USDA Forest Service. 1997. The water/road interaction technology 

series: an introduction. San Dimas, CA: Technology and 

Development Program.

Weixelman, D.A.; Zamudio, D.C.; Zamudio, K.A. 1996. Central 

Nevada riparian field guide. R6-ECOL-TP. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Intermountain Region.

Wissmar, R.C.; Beschta, R.L. 1998. Restoration and management 

of riparian ecosystems: a catchment perspective. Freshwater 

Biology. 40: 571-585.

Wohl, E. 2004. Disconnected rivers: linking rivers to landscapes. 

New Haven, CT: Yale University Press. 301 pages.

Wohl, E.; Angermeier, P.L.; Bledsoe, B.; Kondolf, G.M.; MacDonnell, 

L.; Merritt, D.M.; Palmer, M.A.; Poff, N.L.; Tarboton, D. 2005. 

River restoration. Water Resources Research. 41:10301.

Wright, M.J.; Chambers, J.C. 2002. Restoring riparian meadows 

currently dominated by Artemisia using threshold and alternative 

state concepts—aboveground vegetation response. Applied 

Vegetation Science. 5: 237-246.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 11

Introduction

Meadow complexes are located in distinct geomorphic and hydrologic settings that allow groundwater to be 

at or near the ground surface during at least part of the year. 

Meadows are manifestations of the subsurface flow system, 

and their distribution is controlled by factors that cause localized zones of groundwater discharge. Knowledge of the 

factors that serve as controls on groundwater discharge and 

formation of meadow complexes is necessary to understand 

why meadows occur where they do and how anthropogenic 

activities might affect their persistence and ecological condition. In this chapter, we examine physical factors that lead to 

the formation of meadow complexes in upland watersheds 

of the central Great Basin. We then describe variations in 

meadow characteristics across the region and parameters 

that produce differences in the nature of meadow complexes 

at basin scales. In subsequent chapters, we examine the geomorphic, hydrologic, and vegetation processes that operate 

within individual wet meadow complexes.

Factors Affecting Meadow 

Distribution and Development

Precipitation

Wet meadows require a reliable supply of groundwater 

that supports high water tables year after year and that sustains the phreatophytic vegetation characteristic of these 

discrete ecosystems (Castelli and others 2000). The ultimate 

supply of this water is precipitation. Annual precipitation 

varies from 150 mm/year to approximately 700 mm/year 

in the study area (Oregon Climate Service 2009) and falls 

mostly as snow in winter. Observed spatial variations in 

precipitation closely parallel changes in elevation (figs.1.2 

and 1.4). Watersheds that have a significant portion of their 

drainage area located at high elevations should be able to 

capture more rain and snow and, therefore, have more available water. In fact, it has been demonstrated that stream 

discharge and flow duration are proportional to and can be 

estimated by the size of the drainage basin and the percentage of the drainage basin that is located at elevations above 

3050 m (Hess 2002).

The highest elevations within the six mountain ranges 

in the study area (Shoshone, Toiyabe, Toquima, Monitor, 

Roberts, and Hot Creek Ranges) occur in the central and 

southern portions of the Toiyabe, southern Toquima, and 

central Monitor Ranges (fig. 1.2). The highest annual 

precipitation values are recorded in the central and southern 

Toiyabe and southern Toquima Mountains (fig. 1.4) and, as 

expected, meadow complexes are abundant in those areas. 

In contrast, basins located in sections of mountain ranges 

that do not have significant area at high elevation (greater 

than approximately 2500 m) and that are characterized by 

limited annual precipitation contain relatively few meadows. 

For example, much of the Shoshone Range and the northern and southernmost portions of the Toiyabe, Toquima, and 

Monitor Ranges are lower in elevation and receive less precipitation. Therefore, meadow complexes are uncommon in 

these regions. Analyses of color-enhanced satellite images 

of the region reveal that meadow complexes also are uncommon in low-elevation mountain ranges in the surrounding 

area, including the Pancake Range, Antelope Range, the 

Park Range, and Simpson Park Mountains.

Geologic, Stratigraphic, and Hydrologic 

Controls

Groundwater along riparian corridors of most basins is 

typically located well below the ground surface (usually 

greater than 3 to 5 m), even when an ample supply of groundwater would be expected based on the watershed’s elevation 

and precipitation. Thus, meadow complexes represent an 

anomalous condition where groundwater levels are elevated 

compared to adjacent upstream and downstream reaches of 

the riparian corridor. These spatial changes in subsurface 

water levels raise two important, interrelated questions: 

(1) Is the water that is found within meadows entirely derived from its down-valley movement through valley fill? 

and (2) Are other factors causing groundwater levels to rise 

locally? The meadows may be products of localized inputs 

of water to the valley that raise water levels, of changes in 

hydrologic flow conditions that produce upwelling, or of 

some combination of the two. The answers to these questions require an understanding of the geologic, stratigraphic, 

and geomorphic settings of meadow complexes.

History and Timing of Sedimentation Events. The geomorphic characteristics of the valley bottoms, including 

those in the vicinity of meadow complexes, largely reflect 

erosional and depositional events that occurred during the 

late Holocene (approximately 4500 years BP to the present). The geomorphic history of the basins was documented 

primarily by examining and dating alluvial stratigraphic deposits in approximately 30 upland watersheds spread across 

the central Great Basin (Miller and others 2001, 2004). The 

most detailed studies occurred in the Big Creek, Barley, 

Chapter 2: Controls on Meadow Distribution 

and Characteristics

Dru Germanoski, Jerry R. Miller, and Mark L. Lord
12 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Kingston, San Juan, Cottonwood, and Indian Valley basins 

(fig 1.7). Results indicated that while sediment was always 

being produced, transported, stored, and exported from 

the upland basins, significant temporal variations in sediment production and transport dynamics occurred during 

the late Holocene often in response to discrete changes in 

climate. During the Neoglacial (4500 to 2500 years BP), a 

period of cooler, moister conditions and relatively high vegetation abundance, the landscape was relatively stable and 

little sediment was transported to alluvial fans located at the 

mouth of tributaries (called side-valley alluvial fans) or to 

the alluvial valley floor (Chambers and others 1998; Miller 

and others 2001). As a result, soils formed in the stable valley fill and alluvial fan deposits (Miller and others 2001). 

Landscape stability changed, however, with the onset of the 

post-Neoglacial drought that began in this area approximately 2600 years BP. The post-Neoglacial drought was a time 

of relative aridity, during which upland vegetation changed 

substantially toward dryland assemblages. Available paleoecological data (primarily from woodrat middens) indicate 

that the number of plant taxa present decreased from a relatively high level to the lowest levels observed during the 

Holocene (Miller and others 2001; Tausch and others 2004). 

The decrease in vegetation cover apparently led to erosional 

stripping of hillslope sediment when infrequent but intense 

rainfall events occurred. The eroded sediment was redeposited on side-valley alluvial fans and throughout the valley 

network from approximately 2580+70 to 1980+60 years BP. 

A high frequency of wildfires also may have accompanied 

the drought, as indicated by a large amount of charcoal in 

alluvial deposits that were created during the time period. 

Presumably, destruction of vegetation by wildfires facilitated soil erosion and sediment accumulation in the valleys.

The sediment that was generated during the postNeoglacial drought buried the soils that had developed in 

earlier deposits. Thus, a paleosol dated to approximately 

3500 years BP can be found at the base of most postNeoglacial deposits throughout the region and marks the 

beginning of widespread sedimentation. Stratigraphic data 

from stream-cut exposures and sediment cores indicate that 

deposition within the valley and on the fans usually resulted 

in deposits 0.5 to 2 m thick. In addition, stratigraphic profiles 

revealed that sediment that was eroded from the hillslopes 

was routed through low-order tributaries to the side-valley 

fans causing fan progradation. Fan sediments were then 

eroded and routed down higher-order channels and axial 

valleys resulting in contemporaneous deposition along 

major trunk streams. The process created an interfingering 

relationship between fan and axial valley deposits (fig. 2.1) 

(Miller and others 2001). This alternating sequence of deposition and erosion allowed much of the coarser sediment 

(cobbles and boulders) to be stored in side-valley fans and 

more of the finer-grained materials (pebbles, sand, silt, and 

clay) to be redeposited along the axial drainage system.

A product of fan progradation into the axial valleys was 

a reduction of channel gradients immediately upstream. The 

reduced gradients appear to have further promoted accumulation of sediment along the axial valley (fig. 2.2). In some 

cases, radial fan profiles indicate that fan deposits traversed 

the entire width of the valley, effectively blocking downvalley movement of water and sediment. Although these 

blockages were probably breached rapidly, they may have 

promoted sediment aggradation temporarily by reducing 

downstream flow velocities.

Since about 1980 years BP, the stream systems throughout the region have undergone periods of stability that were 

separated by episodes of channel incision. Interestingly, incision appears to have begun prior to the end of more typical 

moisture conditions during the Holocene (Tausch and others 

2004). Miller and others (2001, 2004) argue that the onset of 

incision was related to depletion of fine-grained sediment on 

hillslopes and reduced sediment loading to the axial valley, 

an argument that is supported by a general increase in grain 

size of the valley-fill deposits through time. The inability of 

the current hydrologic regime to move sediment from the 

hillslopes likely produced the current tendency for modern 

channels to incise in response to natural or anthropogenic 

disturbances.

The depositional history of the upland basins led to a 

rather simple stratigraphic sequence throughout most of the 

valley bottoms (fig. 2.1). However, detailed studies have 

revealed that the stratigraphy upstream of prograding fans 

Figure 2.1. Generalized 

valley fill stratigraphy 

found between wet 

meadow complexes. 

The different 

Quaternary alluvial 

units (Qa1 to Qa4) 

show the ages of the 

valley fill.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 13

and of other areas with dramatically reduced valley width is 

enormously complex. This complexity results from several 

factors: (1) interfingering of axial valley and fan deposits; 

(2) abrupt downstream variations in stream sediment transport capacity upstream of the fans as a result of reduced 

channel gradients and the damming effect of the fans; and 

(3) geologically frequent episodes of channel avulsion associated with localized aggradation of the axial channel. 

Although localized aggradation and avulsion might seem to 

contradict the fact that most channels are currently incising, 

investigations of the avulsion process show that it is associated with the temporary influx of coarse sediment to the reach 

during high-magnitude runoff events. Avulsion is significant 

in that it produces discontinuous lenses of coarse-grained 

sediment that are surrounded by finer-grained materials, creating deposits that are sedimentologically variable.

Data from sediment cores collected in Barley, Birch, and 

Kingston indicate that the greatest volume of Holocene sedimentation occurred from approximately 5250 to 8650 years 

BP (unpublished radiocarbon data). Sediment dated through 

this time period ranges from 2.40 to 12.75 m below the 

surface of the valley fill and pre-dates the Neoglacial. The 

character of these deposits is similar to that found in younger materials, suggesting that the processes responsible for 

formation of deposits during the past 2580 years have been 

repeated many times, creating the stratigraphic architecture 

that comprises valley fill in these drainage basins.

Figure 2.2. Illustration of fan controls. 

Upper two panels show a prograding 

side-valley fan trapping fine-grained 

sediment upstream. Lower two panels 

show a side-valley fan that is buried 

by fine-grained sediment in the axial 

valley.
14 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Field observations revealed that incision not only varied 

along a given channel but between basins, despite the fact 

that timing of deposition and observed stratigraphic relationships within the valley fill were similar. This indicated that 

different watersheds differed in sensitivity to natural and 

anthropogenic disturbance (Germanoski and Miller 2004). 

Landscape sensitivity can be defined in many ways (Allison 

and Thomas 1993), but it is defined here after Brunsden and 

Thornes (1979) as “the likelihood that a given change in the 

controls of the system will produce a sensible, recognizable, 

and persistent response [in the landform of interest].” The 

concept of sensitivity arises from the recognition that many 

fluvial systems are subjected to similar types and magnitudes of perturbation but often respond differently (Schumm 

1991). In the central Great Basin, study watersheds were 

subdivided into four groups with respect to style of geomorphic adjustments during the late Holocene and to sensitivity 

of the axial channel to change (table 2.1; Germanoski and 

Miller 2004). The causes for observed differences in landscape sensitivity among basins cannot be explained entirely 

using watershed-scale parameters (such as basin relief, area, 

shape, drainage density, etc.) but are partly explained by 

differences in basin geology. For example, basins that developed in volcanic rocks were found to be relatively sensitive, 

probably because volcanic assemblages produce small bedmaterial sediment (which can be more easily transported 

than larger debris) and significant runoff.

Detailed mapping of incision depths along the axial valley of basins with continuous channels revealed that the 

amount of entrenchment is highly variable along the riparian corridor and is controlled in many cases by bedrock and 

coarse-grained fan deposits. These deposits often form steps 

in the longitudinal valley profiles and serve as local base 

level controls that dictate the amount of erosion that occurs 

upstream of the side-valley fans.

The region’s geomorphic history has had several significant influences on both the nature and 

distribution of meadow complexes. First, the stratigraphic units that resulted from various erosional and 

depositional events vary dramatically in their ability to store and 

transmit water. Because meadow complexes are groundwaterdependent, variations in the units’ permeability have 

profound influences on subsurface flow along the valley bottom, in general, and meadows, in particular. There is some 

evidence that fine-grained stratigraphic units at or near the 

ground surface are required in order for meadows to form. 

Second, the localized, stratigraphic complexity of the valley 

fill that is often more pronounced beneath meadows complicates the observed hydrologic responses of meadows to 

external disturbances like stream incision. Third, the geomorphic development of the basins has led to sites along the 

valley bottom where valley width and, presumably, depth 

to bedrock are abruptly constricted, thereby decreasing the 

area through which subsurface waters can flow. Not one of 

these factors necessarily results in meadow complexes, but 

in combination they can result in groundwater levels near or 

at the Earth’s surface.

Down-Valley Constrictions of the Unconsolidated Flow 

Field. Groundwater levels along the valley bottom of most 

basins are located several meters below the surface, except 

beneath meadows. A reduction in the cross-sectional area of 

the valley fill can reduce the area through which water that is 

moving down-valley through unconsolidated sediments can 

flow. This mechanism is similar to the effect of a funnel; the 

constriction at the neck of the funnel causes water to pool 

above it. Constriction of a valley’s cross-sectional area has 

Table 2.1. Watershed groups derived from an analysis of basin sensitivity to disturbance.

Fan influence

 and Incision

Relief longitudinal and

Category Geology characteristics Basin shape profile terraces

Group 1

Flood-dominated Volcanic rocks Rugged, high stream Equant, low Low fan influence Localized incision,

power, high shape factor discontinuous

hypsometric integrals terraces

Group 2

Deeply incised Volcanic rocks Rugged, high stream Elongated, Low fan influence, Deeply incised, many

power, high high shape smoothed continuous terraces

hypsometric integrals factor longitudinal profile

Group 3

Fan-dominated Sedimentary Low stream power, Elongated, High fan Localized incision,

and low hypsometric high shape influence, stepped discontinuous terraces

metasedimen- integrals factor longitudinal

tary rocks profile

Group 4

Pseudo-stable Intrusive Moderate to high Equant, low Low fan influence, Localized deep incision,

igneous and stream power, high shape factor stepped discontinuous terraces

siliciclastic hypsometric integrals longitudinal profile

rocks
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 15

Figure 2.3. Lateral and vertical constriction formed by resistant bedrock.

the potential to cause localized pooling, significantly raising 

subsurface water levels. Most meadows are located immediately upstream of valley constrictions that are created either 

singularly or in conjunction with: (1) bedrock protrusions 

from the valley sides; (2) bedrock highs beneath the valley 

fill; and/or (3) accumulation of sediment associated with 

side-valley alluvial fans.

Bedrock Constrictions. The hydrologic damming effect 

of a bedrock constriction is straightforward because permeability of bedrock is generally less than that of unconsolidated 

alluvial valley fill. Thus, the rate at which water can move 

down-valley is greatly reduced by bedrock constrictions. 

Horizontal protrusions of bedrock into valley fill occur 

primarily at three distinct locations: (1) where the geology 

changes, from upstream to downstream, from a less to more 

erosionally resistant rock unit (fig. 2.3); (2) where the channel locally follows the trace of a fracture or fault and remains 

in the same location though time rather than migrating laterally and widening the valley floor as in other areas (fig. 2.3); 

and (3) near the mouth of a tributary where bedrock drainage 

divides project from the hillslope into the axial valley and 

constrict valley width (fig. 2.4). Valley width changes that 

are associated with faults may or may not be associated with 

regional tectonic structures.

While horizontal protrusion of bedrock into a valley can 

be easily observed in the field and on aerial photographs, 

upward (vertical) protrusion of bedrock into the valley fill 

cannot be directly observed. Seismic analyses were used to 

determine if upward protrusions represented a viable mechanism for reducing the cross-sectional area of the valley fill 

(Sturtevant 2007). More specifically, bedrock offsets associated with thrust and normal faults that were known to cross 

upland valleys were evaluated to determine if they created 

bedrock highs and caused decreased thickness of the alluvial fill. Meadow complexes often occur at sites where faults 

align with tributary channels and obliquely traverse upland 

valleys. Bedrock highs could be produced by differences in 

erosional resistance of bedrock units and different rates of 

stream channel incision during valley development.

Seismic (geophysical) analyses of six meadows within 

the Barley, Big Creek, Birch, Corcoran, Kingston, and 

Indian Valley basins determined that both topographic highs 

and faults were present within some but not all of the rock 

units beneath meadows (fig. 2.5) (Sturtevant 2007). Four 

different structural combinations were found: rock units that 

contained both faults and topographic bedrock highs, rock 

units that contained only faults, rock units that contained 

only topographic highs, and rock units that contained neither 

(table 2.2). Importantly, where bedrock highs were found, 

they often occurred immediately downstream of meadows in 

locations where they could exert strong control on groundwater level. Also, topographic highs along the bedrock-valley 

fill contact that were observed in the geophysical surveys 

were collocated (overlain by) with side-valley alluvial fan 
16 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Figure 2.4. Lateral constriction formed 

by a drainage divide.

Figure 2.5. Seismic 

refraction tomography 

profiles in Kingston 

Canyon. The vertical 

panels that represent 

the seismic stratigraphy 

are superimposed on 

an aerial photo of the 

meadow to show the 

location. The bedrock 

layer is shown in the 

blue/dark green layer. 

Light green and magenta 

layers are unconsolidated 

sediment. The fault (black 

line) from the reflection 

data is superimposed 

onto the refraction 

tomography. Note the 

bedrock high in the 

upper left corner of the 

image, which is the 

end of the wet meadow 

complex.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 17

deposits (fig. 2.6). The joint occurrence of fans and topographic highs may result from protection of the bedrock 

from erosion by side-valley fan deposits as the axial channel 

eroded rock units during valley development. Deposition on 

the fans would tend to confine the channel to the opposing 

side of the valley, thereby limiting the amount of bedrock 

erosion that could occur beneath the fans. Regardless of the 

mechanisms responsible for fan formation, the geophysical 

data suggest that, in some cases, bedrock protrusions likely 

play a role in meadow development.

Constrictions Created by Side-Valley Alluvial Fans.

As many as 39 of the wet meadows that were studied are 

located immediately upstream of side-valley alluvial fans. 

Where side-valley tributaries have delivered large quantities 

Constricting

Constricting

Table 2.2. Summary of types and extent of bedrock control on meadow ecosystems 

(modified from Sturtevant 2007).

of sediment to the axial valley, alluvial fans prograde into, 

or even entirely across, the axial valley floor. Thus, fan 

deposits and the landforms that they create can be viewed 

as forming another type of valley constriction in the central Great Basin. Side-valley fans occur as two distinctly 

different morphological types: (1) fans that have distinct alluvial fan morphology and that prograde onto the valley floor 

(fig. 2.7a); and (2) fans that lack a distinct fan-morphology 

but that grade smoothly onto the valley floor (fig. 2.7b). The 

classic prograding fan morphology is easy to recognize and 

the valley constriction is self-evident (fig. 2.7a). Effects of 

graded fans on valley morphology are less obvious to the 

untrained eye, but the physical effects of fan deposits on the 

mainstem axial valley are no less significant (fig. 2.7b).
18 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

The development of prograded versus graded fans is determined primarily by the morphology of the tributary valley, 

which in turn is influenced by the overall geomorphology of 

the drainage basin (Germanoski and Miller 2004). Where 

tributary drainage basins are long and have gentle gradients, 

the tributary valleys have more accommodation space for 

sediment to be stored and, thus, greater sediment accumulation. In such circumstances, side-valley fans are more likely 

to grade into the axial valley fill or to be buried by axial 

valley fill sediments. Where tributary drainage basins are 

short and have steep gradients, tributary valleys have little 

space to accommodate sediment storage and more sediment 

is delivered to the axial valley. In this case, side-valley fans 

are more likely to prograde into the axial valley. Short tributaries and prograding fans are most common in elongate 

drainage basins.

Some prograding fans can be found in basins that do 

not, at first glance, possess an elongate form. For example, 

Big Creek possesses a much more equant morphology than 

Kingston. However, it is clear from evaluating satellite images and aerial photos that the Big Creek drainage basin’s 

morphology appears equant in plan view because it consists 

of two major tributary channels. The Big Creek drainage 

basin is bisected by a drainage divide rather than by the 

trunk channel of a dendritic drainage network as drainage 

basin morphometric analysis assumes. Thus, the elongation ratio (3.6) underpredicts the likelihood that tributary 

channels will be short and steep and that side-valley fans 

will be significant landforms. Corcoran basin, located in 

the southeastern section of the Toquima Range (fig. 1.7), is 

Figure 2.7. A. Meadow upstream of a prograding side-valley 

fan. B. Meadow upstream of a plunging side-valley alluvial 

fan.

Figure 2.6. Wet meadows upstream of side-valley fans in Kingston Canyon, Toiyabe Range.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 19

another example of a basin with an equant shape overall. 

However, the basin is composed of two major tributaries that 

drain from the north (North Fork) and east (Corral Canyon), 

and it has a morphology that facilitates side-valley tributary 

control because individual sub-basins have elongate geometries that favor the influence of side-valley fans. Although 

the elongation ratio of a drainage basin is a good indicator 

that side-valley fan constrictions will be common, these examples illustrate that some drainage basins that are equant in 

shape may have two elongate sub-basins that facilitate sidevalley fan development.

Hydrologic Effects of Side-Valley Alluvial Fans. Unlike 

bedrock protrusions, the effects of side-valley alluvial fans 

on groundwater are more indirect because fan sediments are 

unlikely to reduce the rate of groundwater flow. Field observations and sediment cores taken from five drainage basins 

in the study area indicate that most fan deposits are coarsergrained than axial valley fill sediments. Thus, fan deposits 

are likely to possess higher permeabilities and hydraulic conductivities than valley fill. However, fan progradation often 

results in deposition of fine-grained sediments immediately 

upstream. Observations of 56 meadows in the central Great 

Basin indicate that sedimentation upstream of side-valley alluvial fans and tributary junctions is the most common factor 

influencing development of meadows, followed by sedimentation upstream of bedrock-related geomorphic constrictions 

(table 2.3). The importance of these fine-grained units, which 

possess low permeabilities, is that they are likely to reduce 

down-valley groundwater flow rates, resulting in a rise in 

water levels. Slug test data showed that deposits beneath the 

meadows locally possessed relatively low hydraulic conductivities, on the order of 10-5 cm/s (unpublished data from 

Lord and Jewett). Our observations also indicated that the 

formation of wet meadows, in general, requires accumulation of relatively impermeable fine-grained sediment near 

the ground surface that: (1) retards the ability of the water 

to rapidly discharge at the surface and drain the underlying 

aquifer; (2) creates artesian flow conditions, which allow 

the meadows to remain saturated over long periods of time; 

and (3) forces the water to flow through underlying deposits 

that are finer-grained within the meadow than upstream and 

downstream and that reduce the rate of groundwater flow.

Table 2.3. List of meadows and the geomorphic controls on each meadow’s development. BR = bed rock; 

DD = drainage divide; Fan = alluvial fan; TC = tributary confluence.

Meadow Control Meadow Control Meadow Control

Lebeau Fan Mohawk BR Willow (Monitor Range) DD

Emmigrant 1 DD South Crane Fan West Dobbin DD

Emmigrant 2 Fan Indian Valley Fan/TC Stargo Fan

Cahill 2 Fan Cloverdale Fan East Dobbin Fan

Cahill 3 Fan Corral 1 Fan/BR Wadsworth 1 TC

Johnson 1 Fan Corral 2 BR/Fan Wadsworth 2 Fan

Johnson 2 Fan West Northumberland DD Wadsworth 3 Fan

Johnson 3 Fan Corcoran Main 1 DD Wadsworth 4 DD

Birch Tributary Fan/DD Corcoran Main 2 Fan Mosquito Fan

Birch 1 DD Corcoran Main 3 Fan Danville BR

Birch 2 Fan Corcoran 1 Fan Green Monster BR

Big Creek Fan Corcoran 2 Fan Barley Fan

Kingston 0 Fan Corcoran 3 Fan Barley Trib. DD

Kingston 1 Fan Corcoran 4 Fan/TC Fandango 1 Fan

Kingston 3 Fan Corcoran 5 Fan Fandango 2 Fan

Washington Fan Meadow 1 Fan Little Cow DD/BR

Cottonwood Fan Meadow 2 Fan Six Mile 1 Fan

San Juan 1 TC Round Mountain TC Six Mile 2 Fan

San Juan 2 Fan Red Canyon DD

Figure 2.8. Meadow upstream of the junction of two highorder tributaries.
20 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

A few meadows are located where fine-grained sediment has accumulated above tributary junctions (fig. 2.8). 

However, in this case, enhanced fine-grained sediment accumulated as a result of temporary sediment damming 

upstream of a tributary valley without the formation of 

side-valley fan deposits. This process appears to be most 

prevalent in systems where tributaries are underlain by 

poorly welded volcanic tuffs that produce disproportionately large volumes of fine-grained sediment in comparison 

to basins underlain by sedimentary rocks, crystalline rocks, 

massive welded tuffs, or crystalline rhyolite. In addition, 

the characteristics of sediment deposition from side valley 

sources appear to be related to tributary size. Prograding 

fans tend to form where sediment producing tributaries are 

steep first- or second-order channels, while graded fans form 

when side-valley channels are lower gradient, perhaps thirdorder channels, and tributary junction sedimentation occurs 

where two higher-order tributaries join.

Fine-grained sediment deposition also may be an important component of meadow development upstream 

of bedrock constrictions. Fine-grained sediment often is 

produced upstream of bedrock drainage divides that are associated with tributary channels that project into the axial 

valley, a situation that is commonly observed in the headwater areas of a drainage basin. Also, more than one type of 

fan and/or valley constriction may be present, all of which 

contribute to the development of a meadow (fig. 2.9). An excellent example occurs in Kingston Canyon, located on the 

east side of the Toiyabe Range (fig. 1.7), which is underlain 

primarily by a complex set of sedimentary and metasedimentary rocks of Cambrian and Ordovician age and exhibits 

an elongated morphology with a shape factor of 5.1. As previously noted, elongate basin shapes increase the probability 

that prominent side-valley fans will form by prograding into 

the axial valley. A meadow in Kingston Canyon (Kingston 

3) is located immediately upstream of a prominent, prograding side-valley fan. However, the axial valley is further 

constricted by protrusion of a bedrock hillslope that the fan 

deposits abut against and a graded side-valley fan from a 

tributary on the east (fig. 2.9). These features cause a significant decrease in the gradient of the longitudinal profiles 

of the axial channel and valley floor upstream of the constrictions. The decrease in slope facilitates the accumulation 

of fine-grained sediment, which reduces groundwater flow 

rates through the valley fill.

Although the type of valley constriction that occurs in a 

basin depends on its plan view morphology, every meadow 

is unique, and the causative factors of meadow formation 

are likely to vary even within individual watersheds. For example, Corcoran Canyon is located on the east side of the 

southern Toquima Range, is underlain by volcanic tuffs of 

Tertiary age, and has two major tributaries. The main branch 

has an elongation ratio of 5.2, whereas the west branch has 

an elongation ratio of 4.1. The elongated geometry of these 

basins facilitates development of side-valley fans that have 

the potential to prograde into the axial valley. The eight 

well-developed meadows in Corcoran Canyon are found in 

similar, but slightly different geomorphic settings (fig. 2.10). 

Meadows within the main branch of Corcoran Canyon (labeled Main 1, 2, and 3) all terminate downstream at graded, 

side-valley alluvial fans with some of the fans partially buried by axial valley-fill sediment. However, the geomorphic 

setting of meadow 1 differs in that it is perched upstream 

of a fan that grades onto the valley floor just upstream of 

a bedrock constriction. The position of this meadow likely 

reflects the combined effects of a bedrock constriction and 

graded alluvial fan on sediment deposited upstream of the 

constriction (fig. 2.11). Similarly, five meadows occur in 

the west branch of Corcoran Canyon, but only the first three 

meadows (labeled 1, 2, and 3) are positioned upstream of 

side-valley alluvial fans that are graded to the axial valley 

floor. Meadows 4 and 5 differ somewhat and are located in 

a northern tributary of the West Fork of Corcoran Canyon 

just upstream of tributary confluences (fig. 2.11). Although 

Figure 2.9. Valley 

constrictions downstream 

of the Kingston 3 meadow 

in Kingston Canyon.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 21

detailed stratigraphic data are lacking, geomorphic architecture of the valleys suggests that fine-grained sedimentation 

within the valley of the West Fork of Corcoran Canyon reduced the rate of groundwater flow moving down-valley 

along its tributary channels, creating meadows immediately 

upstream of the confluence. In other words, sediment deposition in the axial valley blocked sediment from entering 

from the northern tributary, thereby allowing fine-grained 

deposits with low hydraulic conductivity to accumulate in 

the tributary above the channel junctions. The net effect is 

that meadows 4 and 5 are in a geomorphic setting different 

from those elsewhere, although the basic factors contributing 

to meadow formation (water supply, fine-grained sediment 

accumulation, and constrictions on flow rates) are present.

Figure 2.10. Eight meadows 

in Corcoran Canyon.

Figure 2.11. Corcoran 

Meadow-fan and 

bedrock control.
22 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Source of Meadow Waters

The general assumption has been that the primary source 

of water to the meadows is precipitation in upstream portions 

of the basin that flows down-valley through unconsolidated 

fill to the meadow complex. While flow through valley 

fill is undoubtedly an important groundwater source, two 

other sources can be important. First, where meadows exist immediately upstream of side-valley alluvial fans, some 

subsurface water is derived from movement of water through 

the tributary valley fill that forms the fan. The importance 

of this source is detailed in Chapter 3. Second, groundwater may be supplied to some meadows as it emerges from 

faults and fractures in the underlying bedrock that traverses 

the axial valleys, as observed in Kingston 3 and Big Creek. 

Faults were found within the bedrock at a number of sites 

(Sturtevant 2007), and it is possible that the water at these 

locations originated in other, adjacent basins. Movement 

and discharge of water along bedrock faults and fractures 

is supported by maps of spring locations on 1:24,000 scale 

topographic sheets (fig. 2.12). Although springs are present in most meadows, springs often occur without meadows 

and, more importantly, frequently align along linear trends 

(fig. 2.12) indicative of structural features such as fractures 

and faults.

Summary

Local and regional analyses show that meadows are 

located in specific geomorphic and hydrologic settings. 

However, each meadow complex is a unique feature and 

cannot be unequivocally described by any single set of causative factors without geomorphologic investigation. Most 

meadows result from a combination of factors, the most 

important of which are an adequate water supply and some 

mechanism that retards down-valley movement of groundwater and causes a rise in groundwater levels. The reduction 

in goundwater flow may be produced by several different 

factors, including the vertical or lateral constriction of the 

valley fill by bedrock and/or a change in grain size of the 

valley-fill deposits. Reductions in grain size, and permeability of the resulting deposits, are commonly associated with 

deposition upstream of side-valley alluvial fans and bedrock 

protrusions. Meadows usually exhibit relatively impermeable, fine-grained sediment near the ground surface that: 

(1) slows the water and prevents it from rapidly discharging 

at the surface and draining the underlying aquifer; (2) creates artesian flow conditions that allow meadows to remain 

saturated over long periods of time; and (3) forces water 

to flow through underlying deposits that are finer-grained 

in the meadow than upstream and that reduce the rate of 

groundwater flow. These factors are discussed in more detail 

in Chapter 3.

Given that meadow complexes are supported by groundwater and that an adequate water supply is needed for their 

continued existence, it is important to determine the source 

of groundwater to the meadows. Several sources, occurring 

either individually or in combination, have been identified, 

the most important of which are: (1) water that is derived 

primarily from precipitation that flows down-valley through 

unconsolidated valley fill; (2) water that moves through alluvial fill and fan deposits within adjacent tributaries; and 

(3) water that is discharged from bedrock faults and springs 

and that may be derived from other watersheds. Any activity 

that reduces the supply of groundwater to the meadow risks 

negatively affecting the meadow’s ecological condition.

Figure 2.12. Location 

of springs mapped 

on 7.5 minute USGS 

Topographic Sheets. 

Note linear alignment 

of springs.

Brewer Canyon Quadrangle, Nevada Tierney Creek Quadrangle, Nevada

Springs

Springs

0 3 km 0 3 km
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 23

References

Allison, R.J.; Thomas D.S.G. 1993. The sensitivity of landscapes. 

In: Thomas, D.S.G.; Al1ison, R.J., eds. Landscape Sensitivity. 

Chichester, UK: John Wiley and Sons.

Castelli, R.M.; Chambers, J.C.; Tausch, R.J. 2000. Soil-plant 

relations along a soil-water gradient in Great Basin riparian 

meadows. Wetlands. 20: 251-266.

Chambers, J.C.; Farleigh, K.; Tausch, R.J.; Miller, J.R.; 

Germanoski, D.; Martin, D.; Nowak, C. 1998. Understanding 

long- and short-term changes in vegetation and geomorphic 

processes: the key to riparian restoration. In: Potts, D.F., ed. 

Rangeland management and water resources. Herndon, VA: 

American Water Resources Association and Society for Range 

Management: 101-110.

Hess, G.W. 2002. Updated techniques for estimating monthly 

streamflow duration characteristics at ungaged and partialrecord sites in Central Nevada. U.S. Geological Survey OpenFile Report 02-168. 16 p.

Germanoski, D.; Miller, J.R. 2004. Basin sensitivity to channel 

incision in response to natural and anthropogenic disturbance. 

In: Chambers, J.C.; Miller, J.R., eds. Great Basin Riparian 

Ecosystems—Ecology, Management, and Restoration. Covelo, 

CA: Island Press: 88-123.

Miller, J.R.; Germanoski, D.; Waltman, K.; Tausch, R.; Chambers, 

J. 2001. Influence of late Holocene hillslope processes and 

landforms on modern channel dynamics in upland watersheds 

of central Nevada. Geomorphology. 38: 373-391.

Miller, J.R.; House, K.; Germanoski, D.; Tausch, R.J.; Chambers, 

J.C. 2004. Fluvial geomorphic responses to Holocene climate 

change. In: Chambers, J.C.; Miller, J.R., eds. Great Basin 

Riparian Ecosystems—Ecology, Management, and Restoration. 

Covelo, CA: Island Press: 49-87.

Oregon Climate Service. 2009. Oregon State University. Available: 

http://www.ocs.oregonstate.edu/index.html. [29 Dec 2010].

Schumm, S.A. 1991. To Interpret the Earth: Ten Ways to be Wrong. 

Cambridge, UK: Cambridge University Press. 134 p.

Sturtevant, K.A. 2007. Integrating multiple geophysical methods 

to analyze geologic controls of riparian meadow complexes, 

central Great Basin, NV. Thesis, Department of Geology, State 

University of New York at Buffalo. 378 p.

Tausch, R.J.; Nowak, C.L.; Mensing, S.W. 2004. Climate change 

and associated vegetation dynamics during the Holocene: the 

paleoecological record. In: Chambers, J.C.; Miller, J.R., eds. 

Great Basin Riparian Ecosystems—Ecology, Management, and 

Restoration. Covelo, CA: Island Press: 24-48.
24 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Introduction

Three geomorphic processes are of primary concern with respect to the current and future state of wet meadow 

ecosystems: channel incision, avulsion (the abrupt movement of the channel to a new location on the valley floor), 

and gully formation. Gully formation often is accompanied 

by upvalley headcut migration and a phenomenon referred 

to as “groundwater sapping” that is defined as erosion of 

bank materials by groundwater flow. In this chapter, we 

examine the effects of each of these processes on meadow 

complexes. Although these processes are discussed separately, they are often interconnected and the rates at which 

they proceed depend on their interactions. Therefore, the 

potential to stabilize or rehabilitate a specific meadow must 

not only include an evaluation of the individual processes 

but also their combined effects.

Channel and Valley Incision

Our interest in channel incision stems largely from the 

potential of a lowered streambed to result in a drop of the 

adjacent water table and a subsequent change in riparian 

meadow vegetation and aquatic habitat. Incision also may 

lead to other detrimental geomorphic effects, including: 

(1) an increase in bank heights, which can decrease the 

frequency and magnitude of overbank flooding and increase rates of bank erosion; (2) a change in cross-sectional 

channel morphology; and (3) a loss in complexity of the 

streambed and an overall decline in aquatic habitat. In general, incision occurs anywhere that sediment removed from 

the reach exceeds the amount entering the reach, provided 

that the stream’s power is capable of moving the bed material (substrate). Both sediment supply and stream power 

vary through time and space. Thus, the magnitude and rate 

of incision vary along the channel at any given time, and 

through time at any given location. In addition, the means 

through which the bed is actually lowered can involve several different processes, depending on the nature of the bed 

and bank materials, the stream’s capacity to transport sediment, and the pre-existing channel morphology. The most 

important of these processes are erosion of the channel bed 

through entrainment of individual particles and the formation and subsequent migration of knickpoints.

Channel Incision by Particle Entrainment

Where an integrated stream network exists, the most 

ubiquitous process through which channels in the upland 

basins incise is through the grain-by-grain entrainment of 

sediment from the channel bed and its subsequent downstream transport at a rate that exceeds its replenishment. 

This grain-by-grain transport process can occur anywhere 

that unconsolidated sediment forms the channel floor but, in 

these study sites, it is most prevalent along stream segments 

that are located between meadow complexes. The tendency 

for incision to occur is driven largely by the region’s history of intense hillslope stripping of fine sediment between 

approximately 2580 and 1980 years BP, a process that 

has reduced sediment input to the axial drainage systems. 

Specifically, the inability of material to be transported off 

of hillslopes and into the drainage network has resulted in a 

general lack of bedload and has contributed to the tendency 

for channels to incise.

Given that bedload transport rates are likely to increase 

with increasing discharge, most incision occurs during 

periods of relatively high runoff. For example, repeated measurements of cross-sectional channel geometry along eight 

incising reaches in five watersheds (Big Creek, Kingston, 

San Juan, Cottonwood, and Washington; fig. 1.7) showed 

that while bed degradation during the low runoff years of the 

early 1990s was limited, incision during the relatively high 

runoff period of 1995 was significant and ranged from 5 to 

36 cm (fig. 3.1a; Chambers and others 1998). Incision was 

accompanied by significant bank undercutting (up to 18 cm; 

fig. 3.1c) as well as by bank loss and/or deposition (-6 to +38 

cm; fig. 3.1b). Deposition along the banks was primarily associated with growth of pre-existing gravel bars. Variations 

in the degree of channel incision and bank modification were 

related to size of the bed material, cover of bank vegetation, 

and age and stem density of willows growing on terrace surfaces along the channel margins.

The correlation between rapid rates of incision with years 

of relatively high runoff also is supported by dendrogeomorphic data. Terraces located along the eight surveyed reaches 

described above were dated by determining the maximum 

age of willows that colonized their surface (fig. 3.2) using 

dendrochronological methods (after Sigafoos 1964; Phipps 

1985). The presumption is that extensive willow colonization occurred shortly after the geomorphic surface was 

formed, and the sediments were no longer being transported 

during low to moderate runoff events (Sigafoos 1964). The 

results show that willow age correlates with height of gravel 

terraces located along the channel. Maximum willow ages 

Chapter 3: Geomorphic Processes Affecting 

Meadow Ecosystems

Jerry R. Miller, Dru Germanoski, and Mark L. Lord
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 25

for the most recent terrace at the time of data collection (in 

1997) were 11 to 12 years, corresponding to high runoff 

events in 1983-1984. The maximum ages of other willows 

clustered around 18 to 20 and 24 years, as measured in 1997. 

These willows presumably colonized new terrace surfaces 

created by channel incision during high flows and overbank 

flooding in the 1970s (1973, 1975, and 1978; fig. 3.3). Older 

stands of willows could not be accurately dated because individual willow stems survive less than 50 years (Chambers 

and others 1998). However, older stands were found on terraces above the geomorphic surfaces that were created in 

the 1970s. Thus, the stands were likely to have established 

either before the recent episodes of channel incision or along 

a limited number of stream reaches that had not incised.

Most watersheds within the study area exhibit convexities in the longitudinal profile of the axial channel, which 

represent zones of inherent instability that are prone to 

entrenchment. Once incised, base level is lowered and 

upstream reaches must adjust. Importantly, spatial variations 

in the rate and magnitude of incision are closely related to 

the degree to which erosion has lowered local base level 

along concaved upstream reaches, most of which are produced by side-valley alluvial fans. Where incision occurs, a 

proportional amount of upstream incision is likely to follow, 

either by means of individual particle transport or through 

knickpoint processes.

Incision by Knickpoint Processes

While channel incision by means of particle entrainment 

and transport is wide-spread, much of the observed incision 

is associated with the localized development and migration of knickpoints. Knickpoints, broadly defined as abrupt 

changes in channel gradient, are generally associated with 

episodes of entrenchment in response to a lowering of base 

level. Detailed mapping of knickpoint distribution along the 

Figure 3.1. (a) Amount of stream incision, (b) 

bank erosion, and (c) bank undercutting 

measured at monitoring cross sections 

during the high runoff year of 1995; SJ = 

San Juan Creek; BC = Big Creek; WC = 

Washington Creek; KC = Kingston Creek; 

and CW = Cottonwood Creek.

Figure 3.2. Willow covered terrace 

surface located along Big Creek. 

Colonization of the surface is 

assumed to occur following 

incision and the cessation of 

annual particle entrainment.

(a) (b) Stream incision (cm) Bank loss (cm)

50

40

30

20

10

0

BC-18

BC-24

CW-11

KC-34

SJ-11

SJ-18

WC-18

WC-24

50

40

30

20

10

-10

BC-18

BC-24

CW-11

KC-34

SJ-11

SJ-18

WC-18

WC-24

0

(c)

Bank under cut (cm)25

20

15

10

5

BC-24

BC-18

CW-11

KC-34

SJ-11

SJ-18

WC-18

WC-24
26 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

downstream reaches of 10 basins, combined with field observations from more 

than 20 additional watersheds in central 

Nevada, demonstrate that knickpoints can 

be found throughout the drainage network, 

with the exception of zero- and first-order 

streams (Germanoski and Miller 2004). 

However, knickpoints are concentrated at 

or immediately upstream of convexities in 

the valley floor. Knickpoints are particularly prevalent at and upstream of side-valley 

alluvial fans that influence valley/channel 

gradients (fig. 3.4). Where these fans occur 

with meadow complexes, knickpoints play 

a critical role in channel incision through 

the meadows.

Experimental and field studies conducted over the past three decades have shown 

that the nature of knickpoint migration and 

evolution can be highly variable from site 

to site (fig. 3.5) and is dependent on the 

composition of the bed material, variations in the material’s resistance to erosion 

(particularly the presence of stratification), 

and the relationship between channel bed 

shear stress and the critical tractive force 

required to initiate particle motion (Gilbert 

1896; Pickup 1975; Gardner 1983; Cosby 

and Whipple 2007). Knickpoints found at 

the toe of side-valley alluvial fans are composed primarily of cobble or boulder-sized 

clasts, which are significantly larger than 

bed material located either up- or downstream of the knickpoint face. The height of 

the knickpoint face is equivalent to the diameter of the clasts that form the knickpoint. 

Thus, the knickpoint represents the cross-channel alignment 

of several large, interlocking boulders that require relatively 

Figure 3.3. (a) Total annual 

precipitation measured for 

Smokey Valley, Reese River, 

and Austin, Nevada; (b) 

mean annual discharge for 

selected stream systems in 

central Nevada.

Figure 3.4. Longitudinal profile showing changes in channel gradients across 

a large side-valley alluvial fan in Kingston Canyon. Note the drop in 

elevation of the valley floor across the fan, a feature that creates a local 

zone of channel instability. Incision through the fan is limited by course fan 

sediments within the channel bed.

Elevation (m)

Overbank Gravel

Deposition

0 10 20 0

1

2

Distance (m)

Elevation (m)

0 10 20 0

1

2

Distance (m)

Elevation (m)

0 10 20 0

1

2

Distance (m)

Elevation (m) Knickpoint

0 10 20 0

1

2

Distance (m)

Elevation (m)4

3

5

0 10 20 0

1

2

Distance (m)

Elevation (m)

Side-Valley

Fan

Terrace

Head of Meadow

Wet Meadow

1995 Drop

in Base Level

0 0 200 400 600 800 1000 1200

8

4

12

16

20

24

28

Distance Downvalley (m)

Fan

Fan

(a)

(b)
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 27

high values of shear stress to be moved (figs. 3.6a and b). It 

is not entirely clear if the boulder-sized material that forms 

the knickpoints is transported into place, or if knickpoints 

represent more resistant zones in the channel bed that are exposed as finer materials are entrained and transported out of 

the reach. It is likely that both mechanisms occur depending 

on the local bed material composition and flow conditions. 

What is significant about these knickpoints is that once one 

or more of the lip-forming boulders are moved downstream, 

finer material immediately upstream of the knickpoint face 

can be transported through the breach. This allows the slope 

of the channel bed upstream of the knickpoint to decline. In 

most cases, the finer material is not redeposited immediately 

downstream of the knickpoint but is transported out of the 

area, resulting in a drop in base level and the evolution of 

knickpoint morphology by means of knickpoint inclination 

(fig. 3.5c). The erosional resistance of these knickpoints is 

important because it largely dictates the rate at which the 

channel bed, composed predominantly of fan sediment, can 

be incised.

Knickpoints along stream reaches that traverse meadows and that are located upstream of the side-valley fans 

(fig. 3.6a) are different from those found within the noncohesive gravels of the over-steepened fan reach. Here, the 

knickpoints are formed in fine-grained cohesive sediments 

that typically underlie a thin veneer of gravel in the channel bed of the meadow complex. These types of knickpoints 

usually migrate upstream through the meadow complex for 

considerable distances and eventually disappear where the 

composition of the channel bed becomes dominated by gravel rather than fine-grained alluvium (i.e., silts, clays, and fine 

sand). During upstream migration of the knickpoint, an inset 

terrace is commonly formed that extends upstream from the 

side-valley fan through the meadow complex and beyond 

(e.g., fig. 3.4b, dashed line). The occurrence of the terrace 

upstream of the meadow (and the known upstream extent of 

knickpoint migration) suggests that the effects of the baselevel drop at the fan are realized over a significant portion of 

the axial drainage.

The style of knickpoint migration and evolution that is 

observed within the meadows is referred to as parallel retreat 

(fig. 3.5a) because the knickpoint face remains roughly vertical as it migrates upstream (fig. 3.6a). Gardner (1983) argues 

that three factors are needed for parallel knickpoint retreat: 

Figure 3.5. Three models of knickpoint evolution described 

by Gardner (1983). Knickpoints in central Nevada 

primarily evolve by (a) parallel retreat when formed in 

fine-grained sediment, and by (c) knickpoint inclination 

when developed in non-cohesive, coarse-grained 

sediment. In the latter case, knickpoint advancement is 

limited, but the process of knickpoint inclination results 

in a lowering of local base level, which is subsequently 

translated upstream.

Figure 3.6. Morphology of 

knickpoints commonly observed 

along incised channels. (a) 

Knickpoint developed in finegrained sediment; (b) knickpoint 

developed in coarse-grained 

sediment. Knickpoints formed 

in fine-grained, cohesive 

sediments migrate upstream 

by means of parallel retreat, 

whereas upstream advancement 

of knickpoints formed in coarse 

sediment is limited. Both 

photographs were taken along 

Kingston Canyon in 1997.
28 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

(1) an erosionally resistant layer that forms the knickpoint 

lip, (2) an underlying unit with lower resistance to erosion, 

and (3) the ability of stream flow to remove sediment from 

the base of the knickpoint. The removal of sediment from 

the base of the knickpoint can create a plunge pool by undercutting the resistant cap layer. The knickpoint then migrates 

upstream (retreats) as the material that forms the knickpoint 

face fails. Knickpoint retreat is commonly observed where 

streams are developed in alluvial materials characterized by 

varying resistances to erosion (Holland and Pickup 1976; 

Patton and Schumm 1981; Gardner 1983; Miller and others 1990), as is the case for most meadow complexes in the 

study area.

Most meadow systems are characterized by deposition 

of fine-grained silts and clays over the valley floor and the 

periodic deposition of sand and gravel both within the channel and as localized, lobate overbank deposits. The latter 

deposits tend to be associated with rare episodes of sediment influx to the drainage network during storm events. 

These diverse depositional sequences result in a layered 

stratigraphy that is prone to incision by knickpoint retreat. 

Erosionally resistant materials required for knickpoint retreat also appear to be related to soil development in both 

fine- and coarse-grained alluvium during periods of relative 

stability. Of particular importance are soils developed in the 

surface of Neoglacial (Qa1, fig. 2.1) deposits that possess 

significant quantities of clay and are particularly resistant 

to erosion. Another important property of these soils (and 

other units with relatively large amounts of silt and clay) is 

that the fine sediment limits vertical groundwater flow. As a 

result, where these fine-grained units are present, horizontal 

flows are enhanced, creating zones of groundwater seepage 

along the channel banks immediately above the less permeable layer. Bank seepage in these areas can be so significant 

that it results in erosion of less resistant (cohesive) bank 

materials, bank undercutting, and subsequent bank collapse. 

Although less obvious, groundwater flow also may lead to 

erosion and undercutting of materials beneath the knickpoint 

lip, particularly in areas that are characterized by upward 

flow gradients and/or artesian conditions (fig. 3.6a). Thus, 

knickpoint retreat appears to be aided by groundwater sapping processes, which tend to be spatially limited to meadow 

environments.

The mechanisms of channel incision correlate closely 

with the size and composition of material in the channel bed. 

Knickpoints along streams that traverse side-valley fans are 

composed of boulders and evolve by knickpoint inclination 

(fig. 3.6b). Knickpoints within meadows are composed of 

cohesive, fine-grained sediments and migrate upstream by 

means of knickpoint retreat. Upstream of meadows, knickpoints are generally lacking, and channel incision occurs by 

entrainment of individual clasts. Given that the current distribution of the geologic materials that form the channel bed 

is related to depositional processes that occurred in the past, 

it follows that the system’s geological history has played a 

significant role in dictating the nature of modern channel 

processes.

An important observation from a management perspective is that once a drop in base level at the fan has taken 

place, further degradation is likely to occur somewhat rapidly. For example, aerial photographs suggest that the axial 

channel in Kingston 3 meadow (fig. 3.4) had been stable 

since at least 1965. Once base level had been lowered by a 

flood in 1995, the entire meadow system exhibited channel 

incision within a relatively short period of time (five years).

In many cases, wet meadows are characterized by an 

axial channel fed by upstream runoff, and one or more 

smaller tributaries fed predominantly by spring flow. During 

knickpoint migration, not all parts of the drainage network 

within these meadows are affected equally. For example, as 

the knickpoint migrated through Kingston 3 meadow, the 

base level drop along the axial stream created additional 

knickpoints within the spring-feed tributary channels. These 

knickpoints have not migrated more than a few meters upstream of the tributary’s confluence with the axial channel, 

presumably because stream power dropped significantly 

(see Cosby and Whipple 2007). However, these knickpoints 

represent points of instability that can lead to rapid channel 

and valley incision under certain conditions.

Gully Formation Along Steep Valleys

 As previously discussed, well-defined channel networks 

are incised by either knickpoint processes or entrainment of 

individual particles. In contrast, unincised meadows or meadows that possess shallow, discontinuous channels are usually 

entrenched by a different set of processes involving gully formation and headcut migration, both of which are promoted by 

groundwater sapping (sometimes called seepage erosion). The 

nature and rate at which these processes occur differ between 

basins, but basins can generally be grouped into two types: 

(1) those characterized by relatively steep valley floors that 

are underlain by highly permeable sediments; and (2) those 

that exhibit low-gradient valleys, relatively large meadows, 

and a mixture of sediment sizes within the valley fill. In this 

section, we discuss the formation of gullies and the resulting 

transport and deposition of sediment within basins that possess relatively steep and narrow valley floors.

Of particular concern is the potential for extremely rapid 

development of relative large gullies. This is prevalent within 

basins that are underlain by quartz monzonites and granodiorites of middle Jurassic age that weather into coarse sand and 

granule-sized sediment (called grus). Grus is particularly susceptible to erosion by groundwater because it is non-cohesive 

and highly permeable, allowing for rapid rates of groundwater flow. As a result, valley incision often involves a positive 

feedback mechanism in which the onset of incision and the 

formation of a distinct channel produce groundwater flow 

convergence, higher effective pore pressures, and enhanced 

seepage erosion and undercutting. As the channel grows, these 

processes are enhanced to the point that upstream headcut migration can occur with little or no overland flow, provided that 

the failed bank material is carried away from the base of the 

slope by groundwater discharge into the channel.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 29

Perhaps the best example of this process (or sequence of 

processes) is provided by Marshall Canyon, a 4.9-km2 basin 

located approximately 2 km south of Austin on the western 

flank of the Toiyabe Range. In May 1998, the valley floor 

in the upper section of the basin was rapidly incised over a 

period of a few days in response to heavy rainfall and melting of a relatively large winter snowpack (fig. 3.7a, b, and 

d). Germanoski and others (2001) found that erosion, deposition, and transport of sediment during and following the 

event occurred in distinct zones, called “process zones,” 

along the valley bottom. These process zones were mapped 

on aerial photographs in June 1998 immediately following 

valley incision (fig. 3.8). The most significant zone of valley entrenchment (Erosion Zone 1; fig. 3.8) was located at 

the head of the drainage system in an area characterized by 

several side-valley springs and the convergence of low-order 

tributaries draining headwater reaches (fig. 3.8). The zone was 

characterized by an unincised valley floor prior to the event. 

However, erosion created a flat-floored trench with nearly 

vertical walls. The trench was about 7 to 10 m wide, up to 6 m 

deep, and terminated upstream in three amphitheater-shaped, 

vertical headcuts that were separated by narrow “islands” of 

valley fill (fig. 3.7a). There was no evidence immediately after the event to suggest that the three headcuts were eroded 

by overland flow. Rather, it appeared that headcut development and migration primarily resulted from a combination 

of seepage erosion (sapping) and slope failure by mass wasting processes. Although headcut development and migration 

were not observed, the following factors were likely to have 

occurred in the process:

• Localized incision of the valley fill along a low-relief 

depression, creating a shallow, discontinuous gully 

system;

Figure 3.7. Major types of process zones recognized along the valley of Marshall Canyon: (a) Erosional Zone 

1; (b) Transport Zone 1; (c) Depositional Zone 1; and (d) Incised channel within Erosion Zone 2. See fig. 

3.8a for process zone locations.
30 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

• Convergence of both surface and, more importantly, 

groundwater flow as the depth of incision increased; and

• A shift in process mechanics away from incision by 

means of individual particle entrainment to incision 

by means of seepage erosion (sapping) and subsequent 

slope failure. The sapping process probably involved 

erosion of particles from the base of the trench, thereby 

undermining the headcut face and destabilizing the 

slope.

Downstream of Erosion Zone 1, sediment removed from 

the trench was transported through a V-shaped channel that 

was produced by incision during the high runoff years of 

1983 and 1984 following partial burning of the basin by a 

wildfire in 1981. This V-shaped transport zone (Transport 

Zone 1) extended down-valley for approximately 100 m 

before terminating in a lobate-shaped deposit labeled 

“Depositional Zone 1” (figs. 3.7c and 3.8). The lobate deposit began as an inset channel fill that spilled onto the 

valley floor, covering a down-valley distance of approximately 60 m. Not all of the sediment that was cut from the 

trench in Erosion Zone 1 was deposited on the lobe within 

Depositional Zone 1. In fact, the majority of sediment produced by the event passed through the reach where it was 

routed into and out of Transport Zone 2 before coming to 

rest as a very large depositional lobe similar to that found 

upstream. The primary difference was that the second deposit was much larger than that found upvalley; it was almost 

400 m long and had a maximum width of 75 m. Stratigraphic 

data show that a channel was present throughout this reach 

(Depositional Zone 2) prior to the 1998 event. The channel 

was completely filled to a depth of as much as 1.5 m during 

the event before deposition spilled onto the valley floor, creating overbank deposits with a maximum thickness of 0.4 m. 

Both the overbank lobate deposits and the channel fill were 

re-incised to depths ranging from 0.5 to 1.5 m immediately 

after sedimentation ceased.

Downstream of Depositional Zone 2, the valley floor 

is incised by two narrow (0.25 m wide) and deep (1.9 m) 

channels that terminate upstream in vertical headcuts (fig. 

3.7d). Incision along this reach of the valley floor (Erosion 

Zone 2) appears to have started well before 1998 and is ongoing, although rather slowly. Farther downstream of the 

convergence, the two channels coalesce and the channel 

widens to a “bankfull” width of 4 m. Ultimately, the channel 

grades downstream onto the valley floor within Depositional 

Zone 3.

Field surveys and cartographic data show that the patterns 

of erosion, transport, and deposition are largely controlled 

by valley morphology. Erosion during the 1998 event occurred in areas where valley gradients and, therefore, shear 

stress were greatest (fig. 3.8). The transport zones created by 

flows in 1983 and 1984 also represent reaches of relatively high gradients in comparison to the depositional zones. 

These reaches did not incise in 1998, presumably because 

they had already been entrenched, and the V-shaped channels that were created were efficient at routing sediment 

downstream. In contrast to zones of erosion and transport, 

deposition occurred where channel gradients decreased and 

valley floor widths increased (fig. 3.8). Thus, the observed 

pattern of erosion and incision following the 1998 event 

reflected a combination of channel gradients, valley width, 

the availability and nature of groundwater flow, and the system’s geomorphic history.

The pattern of gully erosion and deposition that was observed in Marshall Canyon is common in other basins in the 

area, although the rate of gully development is much slower. 

In Corcoran Canyon (fig. 1.7), for example, incised channels are repeatedly associated with narrow, generally steeper 

reaches of the valley floor (fig. 3.9). In contrast, unincised 

reaches of the valley floor are associated with wider, lower-gradient valley segments. Importantly, most meadows 

are found within these wider, lower-gradient environments 

(figs. 3.9 and 3.10). While the meadows are associated with 

valley reaches that promote deposition, they may be affected 

by upstream migration of headcuts, which initially develop 

downstream along narrower, steeper transport zones where 

surface flows are concentrated and tractive forces are higher. 

In addition, incision appears to be enhanced by emergence 

Figure 3.8. (a) Distribution of recognized process zones along 

the valley of Marshall Canyon in 1998; (b) changes in 

gradient and depth of incision along Marshall Canyon in 

1998 as a function of process zone type. Gradient and 

depth of incision are relatively low in depositional zones 

compared to erosional zones.

0 200 400 600 800 1000 1200 1400

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0

1

2

3

4

5

6

7

Distance Downvalley (m)

Gradient

Incision (m) 

E1 T1 D1 T2 D2 E2

Gradient Incision (m) 

D3

(b)

(a)
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 31

of groundwaters under artesian conditions via springs that 

increase surface runoff at the downstream portion of the 

meadows. For instance, in Corcoran Canyon, multiple 

headcuts are found along the downstream segments of the 

meadows where groundwater springs provide additional water to the surface. In summary, entrenchment is promoted 

by a combination of factors, including narrow valleys that 

concentrate surface flows, steeper valleys that increase the 

flow’s ability to entrain particles, and groundwater discharge 

that increases the magnitude and frequency of surface runoff. Reaches of a valley floor that are characterized by one or 

more of these properties are particularly sensitive to incision 

by gully formation and advancement.

Gully Formation, Headcut Migration, and 

Depositional Processes Along Low-Gradient 

Meadows

A few basins in central Nevada (such as Indian Valley 

and Lebeau) possess a number of very large, low-gradient 

meadow complexes (fig. 1.7). Although their valley floors 

may exhibit zones of sediment transport and deposition not 

all that different from those found in Marshall and Corcoran 

Canyons (fig. 3.10), the spatial scale over which the meadows exist leads to differences in the processes that govern 

valley entrenchment. The differences are significant enough 

that they must be considered separately from those previously discussed when developing management strategies for 

meadow complexes.

To date, the most extensively studied valley of this kind is 

within the Indian Valley basin (fig. 3.11), a headwater drainage to the Reese River (fig. 1.7). While the remainder of this 

discussion primarily focuses on Indian Valley, the results 

can be applied cautiously to similar meadow/valley systems, 

including those found farther downstream along the Reese 

River (fig. 2.1).

The most distinctive features along the valley floor of 

Indian Valley are a series of discontinuous gullies. The 

term “discontinuous” refers to the fact that the entrenched 

valley segments are not interconnected. Rather, the gullies 

terminate downstream in fan-shaped deposits that grade 

smoothly onto the valley floor. In contrast, the upstream 

terminus is characterized by a prominent headcut that often exceeds several meters in height (fig. 3.12a). Between 

the up- and downstream termini, the character of the trench 

changes in a semi-systematic manner. For example, one intensively studied gully (fig. 3.13) is approximately 2.5 km in 

length. Within upstream areas, several subparallel trenches 

are tributaries to the main trench and each ends upstream 

in a headcut (fig. 3.13). The main trench is rectangular in 

shape and is up to 4 m deep and 30 m wide. Trench width 

and depth both decrease downstream until reaching the 

Figure 3.9. Spatial variations in valley width and 

gradients along Corcoran Canyon. Channel 

incision commonly begins along narrow, 

steep reaches with high erosive flows and 

migrates upstream where it may negatively 

impact the meadow complex.
32 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

unincised segment of the valley floor at the trench mouth. 

Throughout the incised reach, a stream channel is found on 

the trench floor. Along upstream segments of the trench, the 

channel is characterized by perennial flow, is bordered by 

well-defined floodplains and terraces, and is fine-grained 

(fig. 3.12c). Downstream, flow changes from intermittent to 

ephemeral and the size of the bed material increases until 

Figure 3.10. Down-valley 

profiles measured for 

selected upland drainage 

systems in central Nevada. 

Most wet meadows are 

located on wide, lowgradient reaches of the 

valley floor. See fig. 1.7 for 

meadow locations.

it is dominated by cobbles (figs. 3.12b and d). The shape 

of the stream channel also changes down-valley from 

a bed that exhibits deep, well-defined pools that are connected by narrow and much shallower runs to a relatively 

wide, featureless channel floor that encompasses most of the 

trench. Systematic variations in vegetation also occur in the 

downstream direction; upstream, the floodplain and terrace 

Figure 3.11. Aerial photograph of the Indian Creek valley showing the spatial distribution of wet meadows (circled). 

Entrenched reaches, generally located between meadows, are associated with zones of sediment transport.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 33

Figure 3.13. Aerial photograph of studied discontinuous gully system. Note that some gully headcuts 

are oriented at nearly right angles to the valley slope, suggesting erosion follows the direction of 

groundwater flow. Geomorphic units: VF = valley floor; TRENCH = incised trench long valley; YAF 

= young alluvial fans surface; BAF = older, bouldery alluvial fan surface; BB = basalt bedrock near 

surface associated with Black Mountain (northeast corner of photo). Groundwater measurements and 

vegetation surveys were made along transects (1 through 10). Index map shows study location and 

shape within the basin. See fig. 1.7 for basin location.

surfaces are covered by wet meadow species that creat strip 

meadows along the trench floor (fig. 3.12c). Downstream, 

dry meadow (or drier-end) species are dominant (figs. 3.12b 

and d).

The interactions and importance of surface- and groundwater flow to headcut migration in the Indian Valley meadows 

were analyzed by examining groundwater flow conditions in 

the vicinity of one headcut over a period of approximately 

five years, extending from 2002 to 2007 (fig. 3.14). The data 

Figure 3.12. Downstream changes in channel morphology along a discontinuous gully in Indian Creek valley. 

(a) Upstream headcut; (b) incised trench containing high water table and strip meadows; (c) incised trench 

located downstream of (b); (d) most downstream reach that is dry and characterized by renewed deposition.
34 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Figure 3.14. (a) Topography of an 

instrumented headcut in Indian 

Creek valley. Contour interval is 

25 cm; (b) groundwater table on 

July 14, 2003; (c) groundwater 

table on October 16, 2003. The 

black arrow points to the top of 

the trench. Water table contours 

are based on measurements from 

12 wells, shown in (a).

Figure 3.15. Extent of the 

discontinuous gully system in 

Indian Creek valley in 1961, 

1982, and 2003. (a) Gully 

extension primary occurred 

between 1961 and 1982; (b) gully 

extension between 1982 and 

2003 is thought to have primarily 

occurred during the 1982/1983 

flood, the largest recorded during 

the past century.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 35

suggest that groundwater plays an extremely important role 

in controlling the nature and rate of headcut advancement. 

Indicators of the importance of groundwater on headcut 

migration are: (1) the amphitheater-shaped geometry of the 

headcuts, which is often used as an indicator of erosion by 

groundwater processes; (2) seepage from the headcut face 

and trench walls, particularly during the spring and early 

summer months; and (3) the cross-valley orientation of some 

tributary trenches that are aligned semi-parallel to the general 

direction of groundwater flow rather than with the predominant direction of surface runoff (fig. 3.15b).

Groundwater appears to influence headcut advancement 

by initiating mass wasting processes. It is well known that 

rising water tables and increased pore pressure tend to reduce the strength of alluvial materials, initiating episodes of 

bank failure (Thorne and Lewin 1979; Thorne 1982; Simon 

and others 1999). It can be hypothesized that observed slope 

failures along Indian Valley and other similar valleys correspond to wet periods of enhanced seepage and spatially, to 

zones of flow convergence as governed by the local groundwater flow system. The predominant mechanism of headcut 

advancement appears to be bank failure initiated by temporal 

and spatial variations in groundwater flow and subsequent 

weakening of the bank material strength. This suggestion is 

supported by modeling data generated by Johnson (2004). 

Using a program called Slope/W by Geo Slope International, 

he found that bank stability decreased with increasing head 

levels at the headcut instrumented in Indian Valley (fig. 3.14) 

and that seasonal slope failure was likely during the late 

spring when local groundwater levels were at their highest.

Figure 3.16. Fracture 

exposed in the wall 

of a headcut in Indian 

Creek valley. These 

types of fractures 

presumably influence 

the dimensions of bank 

failure blocks and the 

rate at which headcut 

advancement can occur.

Figure 3.17. Wall of trench located 

downstream of the headcut 

shown in fig. 3.16. The eroded 

“alcove” positioned along the 

base of the bank was likely 

caused by groundwater as it 

emerged from the valley fill. 

This type of undercutting often 

leads to bank failure.
36 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Montgomery (1999) found that headcut advancement 

in California’s Tennessee Valley also was tied closely to 

groundwater-related bank failure mechanics. He argued that 

advancement resulted from development of vertical fractures during periods of drying (desiccation) and subsequent 

failure of the blocks of bank materials that were defined by 

the fractures as water levels rose. The annual rate of headcut 

advancement was dependent on the distance of the fractures 

from the bank face because only one block would fail during an annual wetting and drying cycle. The importance of 

fracture formation to headcut advancement within Indian 

Valley appears to be variable. Some headcuts clearly developed pressure-release fractures during desiccation, and the 

size and rate of failure was controlled by fracture dimensions 

(fig. 3.16). In contrast, fractures were not observed at other 

headcuts, and failed blocks of bank material exhibited a rotational movement. Field observations suggest that differences 

in fracture development were associated with variations in 

the grain size distribution of the bank material, with fractures 

forming in finer-grained sediment composed of expandable 

clays.

The upstream migration of headcuts by the groundwaterenhanced failure mechanism just described can continue 

only if the failed bank material is removed from the base of 

the slope. Until the debris is removed, the slope is stabilized 

by the buttressing effects of the failed sediment (Carson 

and Kirkby 1972). Although seepage was observed to remove some of the basal bank material, most material was 

likely removed by small- to moderate-sized surface flows. 

Thus, headcut advancement involves both a groundwater 

component that initiates bank failure and a surface water 

component that removes failed bank material. During low to 

moderate runoff years, headcuts tend to precede up-gradient, 

parallel to groundwater flow because elevated groundwater 

levels are most likely to lead to headcut instability and failure, all other factors being constant. The development of 

the headcut, then, is a self-enhancing process because once 

it begins to form, the trench will create a convergence of 

surface- and groundwater flow, both of which will promote 

headcut advancement. That is, trench development creates 

the conditions that are conducive to further valley incision 

and upstream headcut migration.

Another means through which groundwater influences 

headcut migration is known as seepage erosion or “sapping.” Sapping refers to the application of an upward force 

by groundwater on individual particles, which reduces their 

effective particle weight and facilitates particle entrainment (Howard and McLane 1988). Over time, entrainment 

and transport of particles produces a hollow or alcove in 

the trench wall that leads to bank failure by mass wasting 

processes (fig. 3.17). Sapping is exacerbated by high rates 

of groundwater discharge, which are associated with highly 

permeable materials, steep groundwater gradients, and layered geologic materials with contrasting hydraulic properties 

that encourage horizontal flow.

A closely related process to sapping is called “piping,” 

a phenomenon that involves the enlargement of existing 

macropores and cavities by groundwater flow (Anderson 

and Burt 1990). The formation of pipes is generally associated with burrows, decaying roots, or other openings created 

by plants and animals. The process tends to be particularly 

prevalent in clay-rich soils characterized by shrink-swell 

processes, which amplify the rate of erosion (Heppell and 

others 2000). Like sapping, piping can locally undermine the 

trench wall and lead to slope failure. Piping is so prevalent 

in Corcoran Canyon that pipe collapse and the subsequent 

removal of the failed bank material by overland flow is the 

dominant mechanism of meadow degradation. Both piping and sapping processes were observed along the trench 

walls of Indian Valley. However, the distribution of pipes 

and undermined banks resulting from seepage erosion is not 

temporally and spatially extensive enough to account for 

all of the advancement of headcuts observed within Indian 

Valley. Nonetheless, sapping and piping are extremely 

important processes because they can erode fine-grained 

particles from beneath many types of headcut treatments that 

are constructed of rock, logs, and other materials, rendering 

the treatments ineffective in a short period of time.

Figure 3.18. Headcut associated 

with a shallow, discontinuous 

channel within a wet meadow 

of Indian Creek valley. Headcut 

migration occurs by plunge-pool 

erosion and undermining of 

the headcut face during surface 

runoff. Photograph taken in June 

1996 during the falling limb of the 

annual snowmelt event.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 37

The short-term rates of headcut advancement within the 

gullies monitored in Indian Valley were on the order of 1 m/

year. The comparison of aerial photographs between 1961 

and 2003 show that headcuts periodically have advanced 

much more rapidly than was measured in the field during 

the observation period (fig. 3.15). It is unlikely that such 

rapid rates of migration (particularly between 1961 and 

1982) could occur by means of the groundwater-induced 

failure mechanism previously described. Thus, it is thought 

that rapid headcut advancement occurs by means of repeated plunge-pool erosion and undermining of the headcut, 

followed by the failure and rapid removal of the material 

during major runoff events such as those in 1973, 1975, 

1978, or 1983/1984 (fig. 3.13). This argument is extremely 

important because it suggests that the mechanisms of headcut erosion differ between periods of “average” and “high” 

runoff and that while the rates of advancement are driven 

by slower-acting groundwater processes during periods of 

average runoff, they are controlled by surface flows in the 

latter. Management strategies aimed at reducing the rate of 

headcut advancement need to consider both sets of processes 

to be effective.

A question of significant concern from a management 

perspective is: how do the large, advancing headcut systems initially form? Montgomery (1999) argues that within 

California’s Tennessee Valley, abrupt channel heads are created once incision by entrainment of individual particles 

exposes the soil B-horizon. In the B-horizons, the soil structure, including vertically oriented fractures, allows for the 

repeated failure of blocks of soil from a near-vertical face. 

The abrupt break in topography can then extend deeper during upstream headcut advancement. Both field and aerial 

photographic data show that, in addition to the large gully 

systems, the valley floor within the 

wet meadow complexes of Indian 

Valley exhibit two distinct types 

of shallow, discontinuous channels. One type of channel is fed by 

overland flow, which enters along 

a uniformly graded slope. Erosion 

and incision along these channels 

occurs by the removal of individual particles by runoff. Channels of 

the second type tend to be slightly 

deeper, and their beds are characterized by one or more small headcuts 

developed below the zone of rooting 

(fig. 3.18). Headcut migration tends 

to occur by bank failure along the 

headcut face. Assuming that these 

two types of discontinuous channels 

represent an evolutionary sequence 

that culminates in the large discontinuous gullies, the development of 

headcuts along the stream in Indian 

Valley would appear to be similar 

to that suggested by Montgomery 

(1999). In these cases, incision 

Figure 3.19. Cattle trail leading to the edge of a headcut in 

Indian Creek valley. The spatial correlation between cattle 

trails and gullies suggest that, in some cases, overland flow 

is concentrated within the trail and is capable of eroding 

the valley fill.

Figure 3.20. Spring, or blowhole, on the valley floor of Indian Creek valley. These 

springs create shallow channels that may eventually be enlarged to create larger 

gully systems.
38 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

begins with erosion of the valley floor by the entrainment 

of individual particles and evolves into a gully once incision 

has reached a sufficient depth to allow for block failure from 

a near-vertical face. Once developed, the self-enhancing nature of the headcuts caused by the convergence of surface 

and groundwater flow allows headcuts to grow deeper as 

they advance upstream.

Incision of the valley floor by particle entrainment and 

headcut advancement are both promoted by saturated conditions. This is likely to explain the tendency for shallow 

channels to be concentrated within wet meadows as opposed 

to drier areas of the valley floor. In contrast, re-deposition 

of sediment downstream within the trench or on the valley 

floor is likely to be associated with a loss of stream power 

(less influent flow) and an increase in suspended sediment 

concentration.

The gully development and expansion that was previously described requires the initial erosion of the valley floor by 

overland flow. The ability of surface flows to entrain particles is strongly governed by the area’s microtopography and 

vegetation characteristics. Any activity that promotes flow 

concentration or reduces vegetative cover (or stem density/

roughness) tends to promote particle entrainment. In Indian 

Valley, a large number of shallow channels and headcuts 

are fed by minor (<20 cm deep) linear depressions that are 

devoid of significant vegetation. These depressions are associated with cattle trails, suggesting that the initial erosive 

process required for gully development could be promoted 

by livestock (fig. 3.19). Other activities such as roads and diversion structures that were intended to reduce channelized 

erosion also created zones of concentrated flow. Thus, these 

wet meadows appear to be particularly sensitive to anthropogenic activities, including the installation of rehabilitation 

structures, which divert flow to other locations of the valley 

floor in an attempt to reduce erosion in an existing gully. 

However, natural processes also can initiate shallow channel systems. One such process is the development of vertical 

springs or blowholes, in which water under extreme pressure 

rises to the surface of the meadow and flows down-valley, 

creating a channel system (fig. 3.20).

Groundwater measurements along the instrumented 

trench of Indian Valley show that gully heads are characterized by effluent flow associated with groundwater 

convergence on the headcut (fig. 3.14). Downstream, the 

in-flow of water from the subsurface becomes seasonally variable before eventually changing to a condition in 

which water is lost from the channel throughout the year. 

Thus, sediment deposition at the mouth of the gullies appears to be related to a change in the relations between the 

surface and groundwater flow systems in the vicinity of the 

trench. In the case of the large, deep gullies, these relations 

are strongly controlled by regional physical features such as 

the nature of the underlying bedrock and valley morphology 

(see discussion on Indian Valley hydrology in the following 

section and Jewett and others 2004), which produce zones of 

downward groundwater flow. However, the observed influent and effluent conditions also are related to the evolution 

of the gully. As headcuts advance upvalley, groundwater 

levels downstream of the headcuts drop, eventually leading 

to a loss of water through the trench floor and to sediment 

deposition (Jewett and others 2004).

Channel Avulsion

The majority of meadow complexes found in central 

Nevada are dominated by fine-grained, often organic sediments. Locally, these fine-grained sediments are buried by 

thin (<1 m thick) sand and gravel deposits (fig. 3.21). In some 

cases, the sands and gravels completely fill a paleochannel 

and spill onto the valley floor as lobate, convex-up accumulations. In other locations, the sands and gravels can only be 

found as convex-up bars. Laterally, the deposits are discontinuous, thinning toward the margins and in the downstream 

direction.

Field and aerial photographic data suggest that these 

coarse-grained deposits were produced by avulsion. Avulsion 

is a process by which the channel is abruptly relocated from 

one position on the valley floor or floodplain to another. In 

a review of avulsion processes, Jones and Schumm (1999) 

subdivided avulsions into four groups based on the factors 

that lead to channel relocation. However, while one avulsion 

process may dominant the system, others may contribute 

to channel relocation and, within a given region, avulsion 

may be caused by more than one set of factors. Therefore, 

care must be taken when attributing causes of avulsion for 

a particular stream. Nonetheless, avulsion within meadow 

complexes of central Nevada appears to be related to clogging of the channel and loss of flow capacity as a result of 

stream bed aggradation. The loss of channel capacity leads 

to overbank flooding and the scouring of a new channel system that bypasses the aggraded reach. This process is well 

illustrated by a 1983 event that occurred along Cottonwood 

Creek on west side of the Toiyabe Range (fig. 1.7).

In Cottonwood, gravel-sized sediment filled a short-reach 

of the axial channel at the upstream end of a wet meadow 

complex (fig. 3.22). The coarse sediment was then ramped 

onto the meadow surface by overbank flood waters, creating 

several gravel bars that were oriented at about a 35° angle 

from the axial channel alignment (fig. 3.22). The bars were 

approximately 15 m long, 5 m wide, and buried finer-grained 

meadow sediments. Flow that emanated from around the 

bars coalesced downstream in a shallow depression in the 

meadow surface and rapidly eroded a narrow, approximately1.5 to 3 m deep channel into the valley fill (fig. 3.22). The 

newly cut channel allowed flows from upstream to bypass 

the aggraded reach, and a piece of the pre-existing channel 

down-valley of the sediment-clogged stream section remained as an abandoned channel (fig. 3.22). Over the next 

several years, the newly cut channel continued to incise and 

widen to accommodate the incoming flows from upstream. 

Comparison of channel photos with cross sectional profile 

data indicated that much of the channel enlargement occurred between 1997 and 1999 (when the first cross-section 

was surveyed), presumably during the relatively high runoff 

year of 1998 (fig. 3.22).
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 39

Figure 3.21. Course 

gravel deposits 

located on the 

valley floor of 

Kingston (a, b, 

c) and Birch (d) 

Canyons. These 

deposits are thought 

to have formed 

during channel 

filling and avulsion 

that resulted from 

the localized influx 

of coarse-grained 

sediment. Flow in 

(a) and (b) is from 

left to right.

A similar process likely occurred within Birch 2 meadow 

(fig. 1.7). However, it differed from the avulsion described 

for Cottonwood in that overbank flood waters flowed downvalley into an existing spring channel that was dominated by 

fine-grained sediment. The spring channel was subsequently 

converted into the axial drainage system through erosive 

processes that deepened and widened the original channel.

The frequency at which avulsion occurs varies from 

one meadow to another. However, it is clear that channel 

avulsion is a fundamental process associated with meadow 

development. For example, older bars partially covered 

by fine-grained sediment are visible as topographic highs 

within the Cottonwood meadow. In addition, the valley fill 

within Kingston 3 meadow (fig. 1.7) exhibits thin, laterally 

discontinuous sand and gravel lenses that are interspersed 

with finer-grained sediments (fig. 3.23). These lenses presumably represent the deposition of sand and gravel during 

channel avulsions, followed by burial with silts and clays 

during overbank flooding. Radiocarbon (C-14) dates obtained from organic materials in the cores show that these 

gravel deposits date back at least 8000 years BP, indicating 

that avulsion has been an integral part of meadow aggradation and development throughout the Holocene.

The idea that channel bed aggradation leads to avulsion 

may seem to contradict suggestions that channels within the 

upland basins of central Nevada are sediment starved and 

tend to incise. Both hypotheses can be correct because aggradation that is associated with avulsion is produced by the 

rapid, temporary influx of coarse sediment to the drainage 

network. This aggradation represents a short-term condition 

that is superimposed on a longer-term tendency for channel incision. In Cottonwood, the near instantaneous influx of 

gravel-sized sediment to the meadow was created by rapid 

remobilization of material stored behind a series of upstream 

beaver dams that were breached during the high flows of 

1983. Other potential sources of sediment that may rapidly 

deliver coarse sediment to the drainage network are mass 

wasting events (such as landslides), localized trenching of 

side-valley fans during episodes of extreme runoff, and/or 

the dissection of roads by runoff (fig. 3.24).

Stratigraphic and cartographic data show that avulsions are 

primarily limited to meadows; reaches of the stream channel 

without meadows show little evidence of past avulsion episodes (Miller and others 2001). This observation results from 

the tendency of sediment that is rapidly flushed into the drainage network to be redeposited within the meadow complex. 

Aggradation within the meadow is probably induced in large 

part by changes in channel gradient that often occur as a result of long-term aggradation of the valley floor upstream of 

side-valley alluvial fans and other valley constrictions. Jones 

and Schumm (1999) argue that aggradation and subsequent 

avulsion also may be related to encroachment of riparian vegetation, which leads to a loss of channel capacity, an increase 

in channel roughness, and a reduction in flow velocities. The 

association of localized aggradation and avulsion in meadow areas that are heavily overgrown by willows, such as in 

Kingston Canyon and Birch Creek (fig. 3.25), suggests that 

riparian vegetation may contribute to aggradation in some upland watersheds.

Summary

Channel incision, gully formation, and avulsion have significantly affected meadow complexes in central Nevada. 

The most widespread impacts are associated with incision, 

which has been observed in most upland meadow complexes 

in the region. The mechanisms of incision vary as a function 

of the underlying bedrock and grain size of erodible material. Incision by the entrainment and transport of individual 

grains occurs along reaches that are characterized by loose, 
40 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Figure 3.22. Channel changes associated with an avulsion that occurred in 1983 along Cottonwood Creek. 

Upstream reaches of the abandoned channel were filled with sediment that was derived from behind failed 

beaver dams. Aggradation within the channel led to overbank flows, deposition on the valley floor, and 

downstream incision of a new channel. Cross sections illustrate changes in the resulting incised channel from 

1999 to 2007.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 41

coarse-grained sediment; whereas incision by knickpoint 

formation and migration occurs along stream segments that 

are characterized by fine-grained, more cohesive sediments. 

In many instances, incision is initiated by a drop in base level along a convexity in the longitudinal profile that is created 

by a side-valley alluvial fan, or by deposition upstream of 

a bedrock valley constriction. Once initiated, incision progresses upstream as the channel adjusts to the lowered base 

level.

Gully formation is predominantly limited to valley systems without an integrated drainage system. Once gullies 

have formed, the rate of headcut advancement varies as 

a function of the overland flow intensity. During extreme 

events, gully formation occurs by means of repeated plungepool erosion and undermining of the headcut, followed by 

failure and rapid removal of the failed bed and bank material. During years characterized by low to moderate runoff 

events, headcut advancement is controlled primarily by 

groundwater sapping processes. Therefore, to be effective, 

management strategies that are aimed at reducing the rate of 

headcut advancement need to consider processes that occur 

during both low flow and high flow years. In addition, observations from Indian Valley indicate that meadow complexes 

are sensitive to activities that may concentrate flow on the 

surface, including trails created by livestock.

Channel avulsion is primarily restricted to low-gradient, 

meadow environments and is induced by the temporary 

influx of coarse sediment, which causes localized channel 

aggradation and filling. The resulting reduction in channel 

capacity (cross-sectional area) forces water over the channel 

banks and results in valley entrenchment at a new location 

within the meadow complex. In some cases, the overbank 

waters are diverted into smaller spring channels, which are 

subsequently converted into the axial drainage system. Data 

from recent avulsions suggest that it may take a few decades 

for an incised channel produced by avulsion processes to 

acquire the morphology that is typical of channels up- or 

downstream of the site.

Figure 3.23. Stratigraphic 

units observed in cores 

extracted from Meadow 

#3 in Kingston Canyon. 

The spatially discontinuous 

nature of the sand and 

gravel units suggests that 

they were formed by 

avulsion processes similar 

to those observed along 

Cottonwood Creek.
42 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Figure 3.25. Gravel deposition 

and channel accretion 

along segments dominated 

by streamside willows.

Figure 3.24. Potential sources of 

temporary sediment influx to axial 

drainage systems in the upland 

watersheds of central Nevada. 

(a) Trenching of previously unincised 

hillslope hollows during extreme 

runoff events; (b) the trenching of 

roads, in this case, Slaughterhouse 

Canyon in 1997; (c, d) the breaching 

of beaver dams and the subsequent 

erosion of stored sediment.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 43

References

Anderson, M.G.; Burt, T.P. 1990. Subsurface runoff. In: Anderson, 

M.G.; Burt, T.P., eds. Process Studies in Hillslope Hydrology. 

Chichester: John Wiley: 365-400.

Carson, M.A.; Kirkby, M. 1972. Hillslope Form and Process. 

London: Cambridge University Press. 475 p.

Chambers, J.C.; Farleigh, K.; Tausch, R.J.; Miller, J.R.; 

Germanoski, D.; Martin, D.; Nowak, C. 1998. Understanding 

long- and short-term changes in vegetation and geomorphic 

processes: The key to riparian restoration. In: Potts, D.F., ed. 

Proceedings: Rangeland management and water resources. 

American Water Resources Association and Society for Range 

Management. 27-29 May 1998; Reno, NV. Herndon, VA: 

American Water Resources Association and Society for Range 

Management: 101-110.

Cosby, B.T.; Whipple, K.X. 2007. Knickpoint initiation and 

distribution within fluvial networks: 236 waterfalls in the 

Waipaoa River, North Island, New Zealand. Geomorphology, 

Special Paper, The Bedrock Geology of Channels: 1462-1476.

Gardner, Thomas W. 1983. Experimental study of knickpoint 

and longitudinal profile evolution in cohesive, homogenous 

material. Geological Society of America Bulletin. 94: 664-672.

Germanoski, D.; Ryder C.H.; Miller, J.R. 2001. Spatial variation 

of incision and deposition within a rapidly incised upland 

watershed, central Nevada. Proceedings of the 7th Federal 

Interagency Sedimentation Conference; 25-29 March 2001, 

Reno, NV. Subcomittee on Sedimentation. v. 2: 141-148.

Germanoski, D.; Miller, J.R. 2004. Basin sensitivity to channel 

incision in reponse to natural and anthropogenic disturbance. 

In: Chambers, J.C.; Miller, J.R., eds. Great Basin Riparian 

Ecosystems—Ecology, Management, and Restoration. Covello, 

CA: Island Press: 88-123.

Gilbert, Grover K. 1896. Niagra Falls and their history. National 

Geographical Monograph 1: 203-236.

Heppell, C.M.; Burt, T.P.; Williams, R.J. 2000. The use of tracers to 

aid the understanding of the herbicide leaching in clay soils. In: 

Foster, I.D.L., ed. Tracers in Geomorphology. Chichester: John 

Wiley: 309-332.

Holland, W.N.; Pickup, G. 1976. Flume study of knickpoint 

development in stratified sediment. Geological Society of 

America Bulletin. 87: 76-82.

Howard, A.D.; McLane, C.F., III. 1988. Erosion of cohesionless 

sediment by groundwater seepage. Water Resources Research. 

24: 1659-1674.

Jewett, D.G.; Lord, M.L.; Miller, J.R.; Chambers, J.C. 2004. 

Geomorphic and hydrologic controls on surface and subsurface 

flow regimes in riparian meadow ecosystems. In: Chambers, 

J.C.; Miller, J.R., eds. Great Basin Riparian Ecosystems—

Ecology, Management, and Restoration. Covello, CA: Island 

Press: 124-161.

Johnson, R. 2004. Groundwater conditions that influence sapping 

induced slope failure in an actively eroding trench system in 

Indian Creek Valley, central Nevada. Cullowhee, NC: Western 

Carolina University. Thesis. 48 p.

Jones, L.S.; Schumm, S.A. 1999. Causes of avulsion: an overview. 

Special Publications in Association of Sedimentology. 28: 

171-178.

Miller, J.R.; Ritter, D.F.; Kochel, C.R. 1990. Morphometric 

assessment of lithologic controls on drainage basin evolution in 

the Crawford Upland, south-central Indiana. American Journal 

of Science. 290: 569-599.

Miller, J.R.; Germanoski, D.; Waltman, K.; Tausch, R.; Chambers, 

J. 2001. Influence of late Holocene hillslope processes and 

landforms on modern channel dynamics in upland watersheds 

of central Nevada. Geomorphology. 38: 373-391.

Montgomery, D. 1999. Erosional processes at an abrupt channel 

head: implications for channel entrenchment and discontinuous 

gully formation. In: Darby, S.E.; Simon, A., eds. Incised River 

Channels: Processes, Forms, Engineering and Management. 

New York: John Wiley and Sons: 247-276.

Patton, P.C.; Schumm, S.A. 1981. Ephemeral-stream processes: 

implications for studies of quaternary valley fills. Quaternary 

Research. 15: 24-43.

Phipps, R.L. 1985. Collecting, preparing, cross dating, and 

measuring tree increment cores. U.S. Geological Survey, Water 

Resources Investigative Reports. 85-4148.

Pickup, G. 1975. Downstream variations in morphology, flow 

conditions and sediment transport in an eroding channel. Zeit. 

Geomorphologie. 19: 433-459.

Sigafoos, R.S. 1964. Botanical evidence of floods and flood-plain 

deposition. U.S. Geological Survey Professional Paper 485-A. 

Washington, DC: U.S. Government Printing Office. 35 p.

Simon, A.; Curini, A.; Darby, S.; Langendon, E.J. 1999. Streambank 

mechanics and the role of bank and near-bank processes in 

incised channels. In: Darby, S.E.; Simon, A., eds. Incised River 

Channels: Processes, Forms, Engineering and Management. 

Chichester: John Wiley and Sons: 123-151.

Thorne, C.R. 1982. Processes and mechanisms of river bank 

erosion. In: Hey, R.; Bathurst, J.; Thorne, C., eds. Gravel-Bed 

Rivers. Chichester: John Wiley and Sons: 1-37.

Thorne, C.R.; Lewin, J. 1979. Bank processes, bed material 

movement, and planform development in a meandering river. 

In: Rhodes D.D.; Williams G.P., eds. Adjustments of the fluvial 

system. Dubuque: Kendal Hunt: 117-137.

Schumm, S.A. 1999. Causes and controls of channel incision. In: 

Darby, S.E.; Simon, A., eds. Incised River Channels: Processes, 

Forms, Engineering and Management. Chichester: J. Wiley & 

Sons: 19-33.
44 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Introduction

The hydrologic regime exerts primary control on riparian meadow complexes and is strongly influenced by 

past and present geomorphic processes; biotic processes; 

and, in some cases, anthropogenic activities. Thus, it is essential to understand not only the hydrologic processes that 

operate within meadow complexes but also the interactions of meadow hydrology with other processes that affect 

these ecosystems. Regional- and watershed-scale analyses 

have contributed to the understanding and management of 

meadows. However, investigation of meadow-scale characteristics and processes have shown that local factors can 

override larger-scale influences and that some processes, especially those related to groundwater hydrology, cannot be 

fully explained by topographically defined watershed-scale 

characteristics (Montgomery 1999; Winter 2001; Devito 

and others 2005). In this chapter, we provide an overview of 

the hydrologic setting within the Great Basin and describe 

and explain key aspects of meadow hydrology for specific 

sites within selected watersheds in central Nevada. Next, we 

discuss generalities in the hydrologic characteristics of 56 

meadows that were assessed in these upland watersheds. We 

conclude by providing an approach for characterizing hydrologic conditions based on hydrologic setting, groundwater 

conditions, vegetation patterns, and stream connections.

Hydrologic Characteristics 

and Processes

General Hydrologic Setting

The geomorphic and hydrologic characteristics of the 

Great Basin provide a framework to understand general 

hydrologic processes and patterns at both watershed and 

meadow scales. The geology, topography, and climate of the 

Great Basin are highly variable across the region and, consequently, the hydrology of the area is complex. Regional 

groundwater flow patterns are strongly controlled by southwest-northeast trending fault-block mountain ranges and, 

in some locations, include deep, interbasin flow through 

permeable bedrock units that connect basins (Mifflin 1988; 

Plume 1996; Maurer and others 2004). In general, mountain 

ranges and flanking alluvial fans are groundwater recharge 

areas, whereas the centers of many basins are groundwater 

discharge zones (Maurer and others 2004). The types of geologic units that underlie the basins and that form the adjacent 

mountain ranges exert strong controls on groundwater flow 

rates and paths. Most bedrock units have low permeability. 

Intrusive igneous rocks and metamorphic rocks generally 

exhibit low permeability and act as barriers to groundwater flow (Plume 1996; Maurer and others 2004). However, 

highly fractured basalt, a volcanic rock, may have hydraulic conductivity values up to about 400 m/day. Sedimentary 

rocks have a wide range of permeabilities; at the high end, 

some carbonate rocks with fractures widened by solution 

have hydraulic conductivity values up to 1000 m/day (Maurer 

and others 2004). Unconsolidated deposits are commonly of 

fluvial origin, and although their hydraulic conductivity is 

highly variable, it may be as high as 670 m/day. Faults can 

differ in permeability from surrounding earth materials by 

up to several orders of magnitude. In general, faults in unconsolidated materials restrict groundwater flow, and faults 

in bedrock enhance flow (Maurer and others 2004).

The locations, volumes, and timing of groundwater recharge and discharge are critical to sustaining montane 

riparian meadow complexes. The interactions of groundwater and stream water are important to understanding these 

systems (Winter 1999; Jewett and others 2004; Newman and 

others 2006; Stonestrom and others 2007). Groundwater recharge in the arid- to semi-arid southwestern United States 

tends to be focused in stream beds and limited areas of headwater regions of mountains rather than over broad, diffuse 

areas as is common in more humid regions (Wilson and 

Guan 2004; Constantz and others 2007; Prudic and others 

2007). Perennial streams, springs, and wetlands are generally groundwater discharge sites that are supported by deeper, 

regional groundwater flow systems (Jewett and others 2004; 

Anderson and others 2006; Newman and others 2006; Patten 

and others 2008). Conceptual models of groundwater and 

stream water interaction in the Great Basin show that streams 

gain in the mountains and lose in the basins (Mifflin 1988). 

At smaller scales, however, the patterns are more complicated. A given stream channel may change between gaining and 

losing over short distances or seasonally (Jewett and others 

2004; Newman and others 2006; Prudic and others 2007).

General Relationship of Meadow Vegetation 

to Hydrology

Montane riparian meadow complexes of the central Great 

Basin are characterized by herbaceous wet and mesic plant 

communities dominated by sedges, rushes, and grasses 

(Weixelman and others 1996; Chambers and others 2004). 

Meadow vegetation patterns are partly controlled by geomorphic setting, soil type, and human uses, but the depth to 

Chapter 4: Hydrologic Processes Influencing 

Meadow Ecosystems

Mark L. Lord, David G. Jewett, Jerry R. Miller, Dru Germanoski, and Jeanne C. Chambers
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 45

the water table is the dominant controlling factor at most sites 

(Allen-Diaz 1991; Chambers and Miller 2004). Different 

meadow plant communities tend to occur along gradients that are controlled by water table elevation (or depth) 

(Castelli and others 2000; Jewett and others 2004; Dwire and 

others 2006). The relationships between depth to groundwater and meadow vegetation types are well-defined for upland 

meadows in the central Great Basin (fig. 4.1a; Castelli and 

others 2000; Martin and others 2001; Chambers and others 

2004). In general, wet meadow communities require water 

table depths during the growing season of less than 30 cm, 

mesic meadow communities require about 55 cm, and dry 

meadow communities require about 120 cm (Castelli and 

others 2000; Jewett and others 2004). Widespread stream 

incision of meadow ecosystems is considered the most important threat to this scarce, ecologically important resource 

that supports a high percentage of the Great Basin’s biodiversity. The magnitude, location, and frequency of stream 

incision are influenced by climate, bedrock geology, alluvial 

stratigraphy, vegetation, groundwater-stream water interactions, and anthropogenic activities (e.g., Germanoski and 

Miller 2004; Weissmann and others 2004). Stream incision 

often results in declines in meadow water tables and can 

cause shifts in plant community types from wetter to drier 

(Chambers and others 2004). The response of plant communities to stream incision is largely controlled by the meadow 

groundwater hydrology, especially the traits of interaction 

between groundwater and stream channels. Understanding 

the linkages among stream, hydrologic, and vegetation processes in meadow complexes is fundamental to effective 

management, stabilization, and restoration of these riparian 

ecosystems.

Figure 4.1. (a) General relationship 

between depth to groundwater 

table and vegetation type; both 

Carex species are part of the wet 

plant community (Chambers 

and others 2004). (b) Seasonal 

relationship between water table 

depth and vegetation type at 

Kingston 3 meadow, 2003 to 2006.

-50

A. 0

-250

-200

-150

-100

Carex rostrata

C

Mesic meadow

Dry meadow

Sage meadow

-300

0.00

B.

Carex nebrascensis

Wet meadow

0.50

1.00

1.50

2.00

Depth to Groundwater Table (m)

2.50

3.00

dry shrub 38% of total area mesic 26% of total area

wet 25% of total area wet / mesic

dry / dry shrub dry / mesic

Depth to Groundwater Table (cm)

April May June July August Sept Oct
46 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Hydrologic Study Approach

The characterization of meadow hydrology was conducted using (1) data collected at meadows that are dispersed 

across the Great Basin of central Nevada, and (2) intensively monitored and studied meadows that were chosen to 

represent the larger meadow population. The study population included 56 meadows located in 33 watersheds over 6 

mountain ranges in the central Great Basin (fig. 1.7). All of 

the meadows that were studied are located in the mountains; 

range in elevation from 2023 m to 2631 m; and, with few exceptions, are located within the Humboldt-Toiyabe National 

Forest. Detailed hydrologic, stratigraphic, and geomorphic 

data were collected at six meadows to document processes, 

test hypotheses, establish causal relationships, and provide 

a basis for interpreting the hydrology of the entire meadow 

population (fig. 4.2; table 4.1). Three of the six meadows 

(Kingston 3, Big Creek, and Indian Valley) were studied 

intensely; data were collected on water table depth, stream 

discharge, stream and channel bed temperature, geophysical 

properties, stratigraphic layers from sediment cores, and 

plant species and communities. These three sites were 

chosen because they are representative of other meadow 

complexes and because multiple years of physical and vegetation data were available. The Kingston 3 meadow, which 

was established as an experimental site in 2003, was the 

most studied site. Water table depths were collected monthly 

during the growing season from 1997 to 2008. Well depths 

ranged from about 0.5 m to 8 m. Groundwater levels and 

water temperature were measured hourly in 24 wells using 

automated water level loggers (pressure transducers). These 

data were used to document diurnal and seasonal variations 

in groundwater levels and longer-term patterns in groundwater flow.

This chapter summarizes data from the three intensively 

studied sites and integrates results with information that was 

collected at other meadows. Collectively, an improved understanding has emerged of meadow processes; hydrologic, 

geomorphic, and vegetation interactions; and management 

implications.

Figure 4.2.

Satellite image 

of central 

Nevada 

mountain 

ranges 

showing 

locations of 

three heavily 

instrumented 

meadow 

sites (yellow 

circles) 

and other 

meadows 

referenced in 

this chapter. 

Meadow 

names and 

number in 

parentheses 

match the 

study site map 

in fig. 1.7.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 47

Hydrogeologic Settings of Kingston 3, Big 

Creek, and Indian Valley Meadows

The general hydrogeologic settings where meadows 

have formed were discussed in Chapter 2. Briefly, the major factors required for meadow formation are a sufficient 

supply of water and a hydrogeologic setting that detains 

groundwater, thereby creating a shallow water table. 

There are a number of geologic and geomorphic settings 

that have created these conditions, but a pervasive trait is 

the occurrence of fine-grained (low hydraulic conductivity) sediments in the down-valley portion of the meadow, 

which are commonly present where there is a local reduction in the cross section of axial valley fill. Whereas 

low-permeability sedimentary materials detain groundwater 

flow to support wet meadow vegetation, most meadows terminate down-valley where unconfined, high-permeability 

sedimentary layers permit rapid draining and lowering of 

the groundwater table.

A common geomorphic setting for meadow complexes is 

immediately upstream of where side-valley alluvial fans project across axial valleys (Chapter 2; Miller and others 2001). 

Because the three intensively studied meadow complexes 

are discussed extensively in this chapter, their geomorphic 

settings are described here. The valley of Kingston Canyon 

has numerous side-valley alluvial fans (fig. 4.3a). However, 

some have created the hydrogeologic conditions necessary 

to support meadow complexes (such as Kingston 3) while 

others have not. One such area (Dry Kingston, fig. 4.3a) was 

studied to understand how the hydrology of this “dry” site 

differs from those that support wetlands (table 4.1). Within 

Kingston 3, the channel is locally incised by as much as 2 m 

below the valley floor. Stream incision is deepest immediately upstream of the side-valley alluvial fan and decreases 

upvalley.

The Big Creek basin is located in the Toiyabe Range 

of central Nevada, to the west and across the divide from 

the Kingston Canyon basin (fig. 4.2). Like Kingston 3, the 

meadow at the Big Creek field site is located upstream of a 

valley constriction that was created by coalescing alluvial 

fans that nearly extend across the entire width of the valley floor to the north (fig. 4.4). Another side-valley alluvial 

fan enters the axial valley near the southern end of the site. 

The Big Creek site is approximately 250 m long and ranges 

from 20 to 60 m wide. The site has a perennial stream, 

Table 4.1. Types of data collected at eight sites in the central Great Basin (figs. 4.2 and 1.7). Two sites, Barley and Kingston Dry, 

were studied to examine the formation or destruction of meadows; Barley did support a meadow prior to stream incision.

Meadow

Big Creek (12)

Indian Valley (22)Kingston 3 (13)Barley Birch 1 (10)Corcorcan 2 (28)Johnson 1 (6)Kingston Dry

Topic Data type

Geology Sediment cores (stratigraphy, texture, % organic) 3 3 14 4 2 0 4 2

Down-hole geophysics (resistivity) • 0

Groundwater

Water chemistry 0 0 • 0 0

Groundwater well level data (monthly) 54 60 99 4 4 3 4

Continuous water level and temperature • 0 •

Hydraulic conductivity data (slug/bail tests) 0 0 •

Stream 

water

Longitudinal and cross section repeat surveys 0 0 •

Stream water and stream bed temperature surveys 0 0 • 0

Water chemistry 0 0 • 0 0

Continuous water level and temperature data • 0 •

Stream gaging • 0 • 0

Meadow

Plant community maps X X X X X X

Spring location, size, and type maps X X X X X X

Ground-penetrating radar survey data • • • • • • • •

Seismic survey data • • • • •

Geomorphic map X X X

# Number of wells and sediment cores at meadow

• Extensive at meadow (>6 locations in meadow)

0 Minimal at meadow (<6 locations in meadow)

X Data were collected and mapped at meadow for listed topic
48 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

flowing south to north, in a channel incised up to approximately 1 m below the valley floor. The channel traverses 

the entire meadow system and links upstream and downstream reaches of the basin. Six small, spring-fed gullies 

flow across the wet meadow to the incised axial channel. 

The site is bounded laterally by steep hillslopes that rise 

sharply above the valley floor (fig. 4.4).

The Indian Valley meadow complex (fig. 4.3b) occurs in 

a different type of setting than Kingston 3 and Big Creek 

(fig. 4.4). Its origin is due to a remnant of a basaltic volcanic mountain located upslope of Black Mountain. Upvalley 

(south) of Black Mountain, a series of broad meadow complexes are present that developed on a relatively thin (about 

8 m) sequence of primarily fine-grained alluvial sediments 

underlain by low-permeability volcanic rocks: rhyolite 

and tuffs (Kleinhampl and Ziony 1985; Jewett and others 

2004). The meadow complex diminishes completely downvalley due to well-developed, incised channels underlain 

by coarser-grained alluvium and higher-permeability basaltic bedrock (Jewett and others 2004). In some locations 

in the meadow, incision exceeds 4 m. Source areas of water 

for this meadow complex are broad, old alluvial fans and 

faults (fig. 4.3b).

Groundwater Hydrology of the Study 

Meadows

Groundwater Spatial Patterns. Groundwater flow rates, 

seasonal patterns, and flow directions vary within a meadow 

and among meadows and reflect the geologic complexities 

discussed previously. The primary controls on groundwater 

conditions at a given location are: (1) stratigraphy (i.e., the 

type, geometry, continuity, and sequence of underlying geologic units); (2) hydraulic conductivity of subsurface materials; 

(3) the water source, particularly whether it is part of a local 

or regional aquifer groundwater flow system; (4) whether the 

source waters that directly support the meadow complex are 

diffuse or discrete (that is, derived from a thick, sedimentary 

unit or through faults and fractures in bedrock); and (5) the 

relationship of groundwater to stream channels. The Kingston 

3 meadow was used to demonstrate groundwater flow patterns because of the extensive stratigraphic and hydrologic 

data available for this site. Information also was used from the 

Indian Valley site (fig. 4.2).

Like many Great Basin meadows, the hydrologic sources 

of Kingston 3 are springs and artesian conditions, and these 

Figure 4.3. (a) Southerly view of Kingston Canyon showing setting common to many meadow complexes, with 

meadows immediately upstream of a side-valley alluvial fan (AF). The Kingston 3 meadow has 99 groundwater 

wells and a stream gage; it was the site of many detailed geologic, hydrologic, and vegetation studies (table 

4.1). (b) Satellite image of Indian Valley showing meadow upstream of valley constriction caused by a volcanic 

mountain. Geology modified from Kleinhampl and Ziony (1985).
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 49

directly reflect the complexity of the subsurface geology. 

The water table depth at the Kingston 3 meadow is shallowest at valley floor edges and slopes toward the stream; the 

water table drops about 12 m in elevation over the length of 

the meadow (about 350 m) (fig. 4.5). An examination of the 

longitudinal, hydrogeologic cross-section demonstrates the 

influence of geology on groundwater flow patterns (fig. 4.6). 

In the upstream portion of the meadow, sediments are mostly 

fine-grained alluvial deposits created by axial valley streams. 

Down-valley, the coarse-grained sediments deposited by 

side-valley fans become more dominant. The interfingering 

of axial valley deposits with side-valley fan deposits resulted in many discontinuous sedimentary units with strongly 

contrasting hydraulic conductivities, which contributed to 

confining layers, artesian conditions, and points of emergence (or discharge) for springs. Discontinuous units also 

were produced by channel avulsion processes. Slug tests, an 

in-well method, were used to determine hydraulic conductivity of subsurface materials. The tests showed values that 

ranged over three orders of magnitude (10-2 to 10-5 cm/s) but 

that probably under-represented the variability because in 

establishing the well field, groundwater wells were preferentially screened in coarser-grained sediments. The meadow’s 

down-valley terminus coincides with the occurrence of continuous sand and gravel deposits (well 10.1; fig. 4.6), which 

permit more rapid groundwater flow and a lowering of the 

water table depth. The influence of stratigraphy of the valley fill and groundwater is indicated by the relationship of 

the shallow groundwater table and groundwater head levels 

from deeper wells (about 8 m). For example, as seen in fig. 

4.6, the water table slopes down-valley and becomes more 

shallow downstream. The deep wells, however, are bound 

by fine-grained stratigraphic units, causing the head levels 

to become increasingly artesian down-valley, reaching levels up to 2 m above the ground surface, before continuous 

gravel layers are encountered and water pressure is released.

A three-dimensional understanding of the stratigraphy 

was obtained by detailed ground penetrating radar (GPR) 

surveys (Sturtevant 2007). As suggested by the core data, 

a facies map produced from the GPR surveys showed that 

Figure 4.4. Site map of the Big 

Creek meadow showing 

the geomorphic setting and 

distribution of groundwater 

wells and stream gaging 

sites.
50 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

the valley fill is characterized by many discontinuous layers 

that generally coarsen down-valley (fig. 4.7). The map also 

showed the occurrence of gravel deposits along the eastern 

valley floor margin, where numerous springs discharge to 

the surface.

Groundwater table and flow patterns in the meadows also 

vary along the valley floor before reaching the side-valley 

fan deposits. In the Kingston 3 meadow, the variability of 

groundwater levels decreases down-valley in both shallow 

and deeper groundwater systems (fig. 4.8). Over a fiveyear period, groundwater levels at the upstream end of the 

meadow varied about an order of magnitude more than at 

down-valley sites. The opposite pattern is present at the 

Indian Valley meadow complex (fig. 4.9), where downvalley wells show much more variability than upstream 

sites. This contrast reflects differences in the hydrogeologic 

settings of the two sites. At Indian Valley, the stratigraphy 

is less complex than at Kingston 3 meadow and the conditions contributing to shallow water tables are gradually lost 

over about 1 km (Jewett and others 2004). At the Kingston 3 

meadow, marked changes in hydrogeology occur over just a 

few meters in some places.

The characteristics of the connection between groundwater and surface water are strong determinants in how the 

Figure 4.5. Kingston 3 

meadow groundwater 

table and well sites. The 

stream is mostly gaining 

through the meadow, 

except at the downstream 

end where it is losing; the 

water table drops about 

12 m over the length of 

the meadow. Groundwater 

table map is for August 

2003, but overall patterns 

change little with time. The 

meadow is instrumented 

with groundwater wells 

(circles); most well sites 

have nests of piezometers 

(n = 99; schematic lower 

left). Green line (center) 

is location of water table 

profile in fig. 4.10. Stream 

flow is south (right).

Figure 4.6. Longitudinal hydrogeologic 

section of down-valley axis of 

Kingston 3 meadow. Lithologic 

columns show a coarsening downvalley; about three-quarters of 

the most downstream core in the 

meadow (well 10.1) is composed of 

gravel. The water table, determined 

from the shallow wells, becomes 

closer to the surface down the 

meadow. The deep groundwater 

shows an increase in artesian 

conditions (see potentiometric 

surface) down the valley, up to the 

point where the meadow terminates 

around well 10.1.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 51

water table and, therefore, vegetation types respond to stream 

incision or migration (Chapter 5). Streams can be viewed 

as gaining or losing depending on whether the groundwater 

flows toward the stream or drains away from the stream. At 

Kingston 3 meadow, much of the stream is fed directly by 

shallow groundwater, thus the groundwater table adjacent to 

the stream slopes to the level of the stream (fig. 4.10a). In 

a losing reach, stream water drains into the groundwater so 

that the water table slopes away from the channel. This is 

the case for some reaches of the stream in Indian Valley (fig. 

4.10b), where the hydrogeologic conditions no longer support shallow water tables.

The source area of the groundwater supporting meadows 

also controls the spatial characteristics of the groundwater 

Figure 4.8. Water levels in nested 

piezometer sites along the 

down-valley axis (fig. 4.5) at 

Kingston 3 meadow; elevation 

is relative. Groundwater levels 

at all depths are most variable 

upvalley. Water levels in the 

deep wells are above the 

groundwater table throughout 

most of the meadow and have 

heads up to 3 m higher than the 

water table in the lower part of 

the meadow (e.g., P84D). The 

increased artesian conditions 

down the meadow are caused 

by fine-grained, confining 

stratigraphic units, which lead to 

high fluid pressure.

Figure 4.7. Ground-penetrating radar facies map of Kingston 3 meadow (from Sturtevant 2007). Upstream units are 

generally fine-grained and continuous, whereas downstream units are coarser-grained and discontinuous. The coarsegrained area at well site 10.1 (see longitudinal section of fig. 4.6) coincides with the down-valley meadow terminus, 

a loss of artesian conditions, and groundwater with a downward flow direction. These changes in conditions are 

attributed to the continuity of the coarse-grained sediments that permit rapid drainage of groundwater that supports 

the meadow upvalley.

P12I

P12D

P13SP22S

P22I

P33S

P33I

P35Sf

P43SP54S

P54I

P54D

P62S

P82I

P84S

P84D

P91S

P101

S

P101I

P101

D

93

94

95

96

97

98

99

100

101

102

103

Hydraulic head (m)

SHALLOW

(water table)

INTERMEDIATE

DEEP

Upvalley > > Well ID Downvalley
52 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

table and flow patterns in meadows. Overall, meadow complexes are groundwater discharge sites, though patterns vary 

depending on the size of the groundwater catchment area 

and when the recharge occurs for that groundwater body. For 

example, discharge areas of regional (large-scale) groundwater flow systems tend to have less variation in head levels 

at daily and seasonal scales and are important to sustaining 

many springs and wetlands (Mifflin 1988; Wilson and Guan 

2004; Anderson and others 2006; Winter 2007; Patten and 

others 2008). The influence of different groundwater sources is evident at Kingston 3 meadow. The upstream portion 

of the meadow is fed by groundwater moving downstream 

through the valley fill. These areas show strong seasonal and 

diurnal variations in water levels (well 33; fig. 4.11). In the 

mid- and downstream portion of the meadow, water table 

depths show little seasonal variation and, in some cases, 

have trends opposite to those in the upstream portion of the 

meadow (fig. 4.11). These traits are indicative of regional 

groundwater discharge sites (Winter 2004; Jewett and others 

2004; Newman and others 2006; Prudic and others 2007). 

Based on the groundwater level and water chemistry data at 

Kingston 3 meadow (Tennant and others 2006), the meadow complex has three primary groundwater sources: axial 

valley water; alluvial tributary water that joins the meadow 

from the east; and, as indicated by seismic data, water from 

a subsurface fault that outcrops under a portion of the west 

margin of the valley side. The influence of these sources also 

is reflected in fig. 4.5, which shows contours of relative water table depths throughout the meadow.

Groundwater Interaction with Stream Water. Evidence 

for multiple groundwater sources supporting meadow complexes can be found by examining the interaction between 

groundwater and stream water. In fig. 4.11, the discharge 

pattern of the stream in Kingston 3 meadow (Stm, bottom 

graph) reflects a complicated composite of different groundwater sources. The stream is perennial within the meadow 

but it is intermittent immediately upstream of the meadow 

and typically flows from late spring to mid-summer during 

snowmelt runoff. Interactions between surface water and 

groundwater were evaluated by repeated, detailed stream 

discharge measurements of the stream and its tributaries 

(fig. 4.12a). Hydrologic budget analysis of stream discharge 

showed that axial valley groundwater feeds the upstream 

end of stream (above gage station K4) but that the springfed tributaries are the primary source of flow downstream. 

When tributary inputs to flow are subtracted, the stream is 

losing in some reaches of the meadow, especially downstream of gage station K2. For example, for the 2004 data 

shown in fig. 4.12a, the stream loses over 30 percent of its 

flow between stations K2 and K1.

Spatial changes along the stream within the meadow also 

were evaluated by installing temporary piezometers directly 

in the stream bed to a depth of 0.5 m. This simple method 

can be used to determine if the stream is gaining or losing 

by comparing the water level in the piezometer to the stream 

water level (Wanty and Winter 2000). The collected data are 

consistent with stream discharge measurements. The vertical 

hydraulic gradient was 0.3 m/m upward at the upstream end 

of the meadow and 0.06 m/m downward in the downstream 

portion of the meadow.

Repeated surveys of stream water and stream bed (15 cm 

deep) temperatures were conducted along the length of the 

stream and its tributaries (fig. 4.12b) to identify gaining and 

losing stream segments and changes in groundwater sources 

(Constantz 1998; Kalbus and others 2006). The temperature profile data showed three distinct patterns in stream 

water temperature: warming in the upstream segment of the 

meadow, cooling to the middle segment of the meadow, and 

subsequent warming downstream (fig. 4.12b). The locations 

of the pattern changes are consistent with the flow data on 

gaining and losing reaches.

Many studies have documented the importance of understanding the exchange between groundwater and surface 

water on stream biotic productivity, the hyporheic zone, 

and biogeochemical cycling (e.g., Hunt and others 2006; 

Newman and others 2006). However, as seen in Kingston 3 

meadow, changes in this interaction can occur over short 

distances and time intervals, so generalizations about a 

stream reach being gaining or losing may oversimplify 

Figure 4.9. Groundwater table elevations in floor of incised 

trench, from upstream (well 8B), midstream (well 5B), and 

downstream (well 3B) reaches at Indian Valley; elevation 

is relative. Note that seasonal water table variations 

increase downstream from less than 0.5 m to over 2 m. 1/1/2000 1/1/2001 1/1/2002 1/1/2003 1/1/2004 1/1/2005 1/1/2006 1/1/2007

1/1/2008

23.5

24.0

24.5

25.0

25.5

26.0

26.5

28.0

28.5

29.0

29.5

30.0

30.5

31.0

34.0

34.5

35.0

35.5

36.0

36.5

37.0
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 53

reality. Newman and others (2006) indicated that small-scale 

changes in the type of exchange between groundwater and 

surface water are relatively common in semi-arid systems 

and can result from changes in geology and variations in 

runoff inputs.

Meadow Hydrology Temporal Patterns. While some 

temporal patterns relate to spatial controls were discussed 

previously, natural events (precipitation, snowmelt, occurrence and length of growing season, climatic change, etc.) 

also have significant effects on hydrologic processes. We 

Figure 4.10. Groundwater table profiles across a gaining and losing channel reach. Schematic diagrams show relationship 

of water table and flow directions to stream. (a) Gaining reach at Kingston 3 meadow; water table slopes toward channel 

(profile location shown by green line on fig 4.5). (b) Losing reach at Indian Valley meadow; water table slopes away from 

channel of incised trench. (c) Aerial photograph shows geomorphic setting. Upstream portions of Indian Valley are mostly 

gaining but become losing down-valley with distance from the water sources and as the permeability of the subsurface 

materials increases.
54 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

use the hydrologic and hydrogeologic data from the Big 

Creek study site to illustrate short-term and long-term temporal patterns in meadow hydrology. The Big Creek site has 

been continuously monitored since it was instrumented with 

54 piezometers in 1997 (Jewett and others 2004).

The Big Creek meadow is located upstream of a valley 

constriction that is created by coalescing alluvial fans that 

extend nearly across the entire width of the valley floor to 

the north (fig. 4.4). Another side-valley alluvial fan enters 

the axial valley near the southern end of the site. Sources of 

water to the groundwater system at the Big Creek site are 

subsurface flow moving down-valley in the valley-fill sediments, the side-valley alluvial fan located near the southern 

boundary of the site, and discharge from the stream. Contour 

lines of water table surface (fig. 4.13) indicate that the main 

direction of subsurface groundwater flow is down-valley in 

a southwest to northeast direction. The largest component of 

groundwater flow is water moving through the thick valleyfill sediment sequence. The lateral constriction caused by 

narrowing of the valley on the north end of the site combined 

Figure 4.11. Groundwater and 

stream water levels (Stm) of 

Kingston 3 meadow sites. 

Groundwater plots show water 

levels of deep and shallow 

wells in successively downvalley wells, from top to bottom. 

Well site 33 shows a smooth 

seasonal signal, fed by axial 

valley groundwater (index 

map, blue arrow), while well 

sites 54 and 85 are more flashy 

and are influenced strongly by 

groundwater from the highgradient tributary valley (orange 

arrow). Vertical hydraulic 

gradient is small at well site 33, 

strongly upward at sites 54 and 

84, and downward at site 101.

stream

flow

99.0

99.5

100.0

33

50 m

N

water level (h) in shallow well

water level (h) in deep well

98.0

98.5

54

97.0

97.5

98.0

98.5

84

95.5

96.0

96.5

97.0

97.5

96.0

96.5

101

water level elevation, meters

94.5

95.0

93 5

94.0

94.5

95.0

Stm

93.0

93.5

91 7

91.8

91.9

92.0

91.6

91.7

LOGGER

MALFUNCTIONS

3/1/2006 6/1/2006 9/1/2006 12/1/2006 3/1/2007 6/1/2007
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 55

with a vertical thinning of the valley-fill sediments creates 

a bottleneck for subsurface flow. This flow constriction 

produces saturated soils and groundwater discharge zones 

that are characteristic of the meadow complexes. The configuration of the water table (fig. 4.13) also suggests that 

the side-valley alluvial fan in the southern area of the site as 

well as the stream influence groundwater flow patterns. The 

pattern of the water table near the side-valley alluvial fan 

indicates it is a source of subsurface flow. The water table 

contours slope toward the stream (gaining) in some places and away from the stream (losing) in others (fig. 4.13, 

arrows).

The impact that different water sources have on the 

groundwater system varies over time due to seasonal 

changes and fluctuations in timing and amounts of annual 

precipitation. Figure 4.13 presents water table maps for 

both a wet season monitoring event (that is, high water table conditions; 25 June 1998; fig. 4.13a) and a dry season 

Figure 4.12. (a) Stream discharge data in Kingston meadow for 

summer and fall 2004. Data show strong seasonality, with 

flow in the main channel that is over three times greater in 

June than in November. In the upstream, flow in the main 

channel is primarily from groundwater; downstream from 

mid meadow, most flow is from tributaries. (b) Stream water 

and stream bed (depth ~15 cm) temperature plot shows 

increased temperature at about 350 m, reflecting warmer 

groundwater contribution from the east tributary valley.

Figure 4.13. Big Creek water table maps illustrating (a) high 

water table conditions (25 June 1997) and (b) low water table 

conditions (09 August 2000). Water table elevation values 

are relative; 1 m contour interval. Arrows show groundwater 

flow directions; stream flow is northerly (top). Base maps are 

fig. 4.4.

monitoring event (low water table conditions; 09 August 

2000; fig. 4.13b). During wetter conditions, the water table 

is higher across the site, with the greatest increases in the 

sage meadow zone located in the upper region of the site 

(for example, water levels near piezometer No. 7 increased 

by approximately 3 m). Water table elevations in the wet 

meadow zone also increased but not by nearly as much. The 

water table in the wet meadow zone is at or near the ground 

surface, and higher water levels (greater hydraulic heads) result in increased groundwater discharge, which flows across 

the ground surface in small channels and eventually enters 

the stream. Field observations revealed that the area of saturated soils, indicating groundwater discharge, was greatest 

when the water table was high.

Both maps of the water table (fig. 4.13) show that the 

side-valley alluvial fan in the southern area of the site 

and the stream traversing the entire site have an influence 

on groundwater flow patterns, but that influence is less 

pronounced when the water table is higher. During wet conditions (fig. 4.13a), water level contours only deflect slightly 

down-valley near the side-valley alluvial fan, suggesting 

that the fan supplies flow to the subsurface. However, the 

magnitude of subsurface flow that was contributed by the 
56 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

fan relative to the contribution provided by subsurface flow 

in the valley-fill sediments is greater during drier conditions 

(fig. 4.13b). The impact of groundwater flow to and from 

the stream channel also is more evident during drier conditions. The downstream reach of the stream adjacent to the 

wet meadow (fig. 4.13; light blue) is gaining during both wet 

and dry conditions. However, upstream the influence of the 

stream on groundwater flow patterns increases as site conditions become drier and the water table elevation decreases 

(fig. 4.13b).

To examine the temporal and spatial interaction between 

surface and subsurface flow, stream discharge was measured 

at six gaging stations during the spring/summer and fall seasons from 2003 to 2006. The locations of the gaging stations 

are shown in fig. 4.4. Figure 4.14 shows the discharge measured at each gaging station (in cubic feet per second, cfs) 

for seven dates over three years. Stream flow ranged from 

0.6 to 3.3 cfs, except during a high flow event recorded in 

June 2005 when discharge measured 10.3 cfs. During this 

event, a gradual decline in streamflow was observed from 

stations G1 to G4 indicating losing conditions upstream. 

Stream discharge gradually increased from stations G4 to 

G6, suggesting gaining conditions downstream. Stream 

flow recorded during the other spring/summer measurement 

events ranged from 1.7 to 3.3 cfs. In June 2003, gaining conditions occurred upstream (between G1 and G3) followed 

by losing conditions mid-stream (between G3 and G4) and 

gaining conditions downstream. The length of the upstream 

segment that exhibited gaining conditions decreased as 

stream discharge decreased. Stream flow was lowest during 

the fall (November 2003 to 2005; 0.6 to 1.3 cfs) following 

the dry summer season. Fall gaging records showed that 

flow in the stream increased only slightly from location to 

location in the downstream direction.

Water table depth data that were collected over time 

provide a glimpse of the hydroperiod, or the frequency 

and amplitude of water-level fluctuations (Winter and others 1998), for different portions of the Big Creek meadow. 

Figure 4.15a illustrates the water table depth (mean depth 

± 1 standard deviation) from 1997 to 2006 for piezometers 

Figure 4.14. Stream 

discharge (2003 to 

2006), Q (in cfs), 

measured at six gaging 

stations located along 

the stream at the Big 

Creek study site. See fig. 

4.4 for gaging station 

location G1 to G6.

0.0

2.0

4.0

6.0

8.0

10.0

12.0

123456

Gaging Station

Q (cfs)

Jun-03

Jun-04

Jun-05

Jul-06

Nov-03

Nov-04

Nov 05

located in the sage, dry, and wet meadow zones. Water table 

depth is greatest in the sage meadow zone. Average water 

table depths in the sage-dominated meadow range from 2.5 

to 3.5 m below the ground surface, but depth to the water 

table varies greatly across this zone (as depicted by the error 

bars). Average water table depths in the dry meadow zone 

range from 0.5 to 1 m and are less variable. The water table 

is closest to the surface in the wet meadow, with the average 

depth generally less than 0.5 m. Water table depths in the wet 

meadow are the least variable. As the hydraulic head in this 

zone increases, the water level can only rise to the ground 

surface, after which further increases in the hydraulic head 

are marked by increases in groundwater discharge.

Average depth to water table also reflects the amount 

of precipitation received in the Big Creek watershed (fig. 

4.15b). The water table was highest (that is, the depth to water was at a minimum) during the wet years of the late 1990s, 

and it was lowest from 1999 to 2004 in response to lower 

than average precipitation. Groundwater levels increased 

in 2004 and 2005 as annual precipitation increased. Water 

table depths generally reflected the influence of evapotranspiration during the growing season for both the dry and wet 

meadow zones. During most years for which data are available, water table depths declined during the growing season 

in the dry and wet meadow zones. This trend was likely due 

to increased plant transpiration and evaporation from the 

wet meadow surface. Water levels showed a rebound in the 

fall when evaporation was less, plants became dormant, and 

transpiration was minimal.

Hydrographs (time series data of water table depths from 

piezometers and the stream), also exhibited these seasonal 

and annual trends and fluctuations (fig. 4.16). Three piezometers (P-201, P-202, and P-203) were instrumented with 

water-level loggers to obtain continuous water level records. 

P-201 was located in the sage meadow zone, P-202 was in 

the wet meadow zone, and P-203 was just down-gradient 

of the wet meadow at the northern end of the site (fig. 4.4). 

The stream also was instrumented with a datalogger that was 

located at gaging station G5 (fig. 4.4). The hydrogaphs for 

P-201, P-202, and P-203 exhibited the same annual pattern. 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 57

Water-level elevations were at their highest during the spring 

snowmelt, which usually occurs in May (fig. 4.16). Water 

levels decreased throughout the growing season probably 

due to reduced rainfall in the summer months and the loss of 

water through increased evapotranspiration. As the growing 

season ended, water levels increased. Water table elevations 

also showed a slow increasing trend throughout the period 

of record (2003 to 2006). This corresponds to the general increase in annual precipitation since the 2000 water year (fig. 

4.15b). In addition, the hydrographs showed the influence 

of storm events on the water table. P-202 and P-203 were 

responsive to precipitation events because they were located 

in or near the wet meadow, where the water table is near the 

ground surface. P-201 was not as responsive to precipitation 

events because it was located in the sage meadow where the 

water table depth was greatest. Large precipitation events 

still affected the water table in the 

sage meadow, but the change in 

the water level was not as rapid as 

where the water table was closer 

to the surface.

Although not measured, plant 

transpiration and surface evaporation appeared to affect the 

water table depth in and around 

the meadow complex. Water 

level fluctuations were greatest 

during the growing season and 

least during the non-growing 

season (fig. 4.16). These fluctuations were more pronounced in 

piezometers located in or near the 

wet meadow (P-202 and P-203). 

The daily periodicity of the water level fluctuations was evident 

when portions of the hydrographs 

were enlarged in order to better 

observe the diurnal fluctuations 

during portions of the growing 

season (June to July 2004) and the 

non-growing season (November 

to December 2004) (fig. 4.17). 

During the growing season, water levels began to drop about the 

time sunlight hit the meadow. The 

water table declined throughout 

the day and reached the lowest 

levels in the evening when the 

meadow became shaded from the 

sun by the surrounding steep terrain. The level of the water table 

then recovered (rose) overnight. 

The hydrograph for P-202, which 

was located in the wet meadow, 

showed the greatest fluctuation 

in water levels, up to 17 cm daily 

from October 2003 to 2006. The 

same periodicity in water level 

fluctuations was present in the hydrograph for P-203, but the 

magnitude of the diurnal change was less. This piezometer 

was located just outside of the wet meadow zone and was 

probably affected by different soil:plant water relations. The 

P-201 (sage meadow) hydrograph showed minimal change, 

but the daily periodicity was still evident. Diurnal fluctuations also were evident in the stage records for the stream 

and were probably due to a daily decrease in baseflow to the 

stream from subsurface sources because of evapotranspiration demands.

Daily water level fluctuations in the hydrographs were 

minimal or nonexistent during the non-growing season 

(fig.4.17). Diurnal fluctuations occurred in piezometer P-202, 

but the magnitude of change was less than that observed during the growing season. These fluctuations may have been 

due to evaporation of water from groundwater discharge 

Figure 4.15. (a) Average depth to groundwater (± 1 SD) in piezometers located in wet, 

dry, and sage plant communities of the Big Creek meadow, January 1997 to January 

2006. Water level measurements were taken monthly during growing season, five to 

six times per year. (b) Total water year precipitation at Big Creek SNOTEL site; line is 

27-year average (66.8 cm).

0.0

1.0

A.

2.0

3.0

4.0

5.0

Jan-00Jan-02Jan-05

Depth (m) to Groundwater Table

Jan-97Jan-98Jan-99Jan-01Jan-03Jan-04Jan-06

Wet Dry Sage

60

80

100

120 B.

0

20

40

Total Precipation (cm)

W ater Year

(Oct 1 - Sep 30)

1997 1998 1999 2000 2001 2002 2003 2004 2005 2006
58 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

zones when sunlight was on the wet meadow. Diurnal fluctuations were not observed in the other hydrographs.

The temporal changes in hydrologic processes and patterns at the Big Creek site illustrate the role of multiple 

variables on meadow conditions. There are predictable 

seasonal cycles of fluctuations in water table depths that 

correspond with timing of plant growth cycles, snowmelt 

runoff, and precipitation. Water level data from four groundwater wells and the creek at Kingston 3 meadow (figs. 4.2 

and 4.3) illustrate this pattern. Figure 4.18 shows water level 

data for the 2005 calendar year that were normalized to percent of maximum water level. That is, all water level data 

were recalculated for each well to percent of maximum water level for 2005. For three well locations (101S, 87D, and 

33D) and the stream, water levels patterns showed two distinct patterns: rising water levels that were most pronounced 

from May through June, and falling water levels. While the 

recession began immediately after maximum water levels for 

most sites, the water table at the site of well 33D remained 

high from mid-May to August before declining. The rising 

stage occurred over a shorter time period than the falling 

stage. This pattern was especially pronounced at well 33D, 

where more than 50 percent of the annual rise occurred over 

a two-week period—a similar pattern to Kingston 3 meadow, 

Figure 4.16. Threeyear hydrographs 

for piezometers 

instrumented with 

dataloggers in Big 

Creek meadow.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 59

adjacent to the stream. Differences in responses between 

sites were most likely due to differences in the timing and 

location of groundwater recharge for different groundwater 

sources. The short timeframe for the rising portion of the hydrographs suggests that the meadow may be very sensitive 

to changes that occur in the amount or timing of recharge 

in the source regions. These general patterns are consistent 

with studies of groundwater recharge in arid and semi-arid 

regions, where groundwater recharge through losing streams 

(that is, stream-focused recharge) is an important process 

(Constantz and others 2007; Prudic and others 2007). From a 

management perspective, this suggests that source areas for 

groundwater recharge need to be considered when evaluating meadows for management activities (Chapter 5).

General Hydrologic Traits of the Study 

Meadows

In general, the riparian meadow complexes in the mountains of the central Great Basin are groundwater discharge 

zones with shallow water table depths that commonly have 

springs, artesian conditions, and perched water tables. 

However, the specific traits of each meadow may vary widely. These variations result in large part from the stratigraphic 

and geomorphic conditions that have developed over hundreds to thousands of years along the hillslopes and valley 

bottoms, but particularly within and immediately adjacent 

to meadow boundaries. Individual meadow characteristics 

Figure 4.17. Sections of 

hydrographs in fig. 4.16, 

illustrating water level 

fluctuations recorded 

during (a) a growing 

season (June 2004) and 

(b) a non-growing season 

(November 2004) in Big 

Creek meadow.
60 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

result from the cumulative interplay of vegetation, watershed 

and stream physical processes, climate, and anthropogenic 

activities. Despite the variation in meadow conditions and 

processes, general hydrologic traits are apparent based on 

observations at the 56 meadows studied.

In about half of the meadows studied, the shallowest 

water table is located in the center of the valley rather than 

adjacent to or nearby a stream. This observation is supported 

by the mapped spring locations and groundwater-dependent 

wet meadow vegetation. In other meadows, the shallowest 

water table occurs at the edge of the valley floor against 

the valley hillslopes and is typically fed by springs or occurs next to shallow streams. Stream channels are present in 

all meadow complexes, but they vary greatly in size, flow 

characteristics, bank materials, and the degree to which they 

affect meadow hydrology.

In many meadow complexes, springs create perennial 

channels and support shallow groundwater tables. Springs 

emerge at sharp breaks in slope or where there are heterogeneities in the underlying geology, such as faults (Chapter 2). 

Springs are present in 75 percent of the meadows, and 

20 percent of the meadows have more than 10 mapped 

springs. They vary in shape, size, and flow rate and range 

from discrete, bubbling springs at the head of channels (fig. 

4.19a), to diffuse seep zones on the valley floor or along 

channel banks (fig. 4.19b), to piped flow out of exposed 

banks (fig. 4.19e). Springs often are associated with shallow water tables and wet meadow vegetation unless they 

have well-developed or incised drainage channels. Springs 

are important to many wetlands in the Great Basin and in 

other arid and semi-arid regions (Tooth and McCarthy 2007; 

Patten and others 2008). Perennial springs in these regions 

are commonly sustained in part by deep outflow from regional groundwater systems (Anderson and others 2006).

Artesian conditions, where groundwater is under enough 

pressure to rise above the land surface, have been observed 

in piezometers of most instrumented meadows (fig. 4.19c). A 

natural expression of artesian conditions is a bubbling spring 

on a horizontal ground surface. At the Kingston 3 meadow, 

three artesian “pipes” have been identified (fig. 4.19f). These 

pipes are naturally formed vertical shafts that range in diameter from about 15 to 50 cm and that connect the land surface 

to a confined aquifer (up to 1.5 m deep). The pipes probably 

formed by erosion of unconsolidated sediments by highpressure groundwater from an underlying confined aquifer 

as it worked its way to the surface. Another expression of 

artesian conditions is a blister or spring mound (Ashley 

and others 2002; Tooth and McCarthy 2007). Artesian blisters represent areas where very low-permeability soil has 

blocked and been elevated by an accumulation of upward 

moving groundwater. Walking on one of these blisters is 

very much like walking on a waterbed. In the central Great 

Basin, blisters reach up to 0.5 m in height, are several square 

meters in area, and have been observed in six meadows.

Perched groundwater conditions are very common in 

the meadows. Perched conditions occur where shallow 

groundwater is underlain by a low-permeability layer that is 

separated by unsaturated materials from the deeper, regional 

groundwater table. Some meadow complexes (e.g., Johnson 

and Corcoran; fig. 4.2) are largely supported by perched water tables. Groundwater wells can be used to determine if 

conditions are perched (fig. 4.20b); however, the presence of 

a small, shallow stream immediately adjacent to sagebrush 

often indicates perched conditions in the field (fig. 4.19d). 

Another indicator of low-permeability layers is how wet 

and mesic plant communities are distributed in relation to 

small-scale topography. The Corcoran meadows are blanketed by a fine-grained, low-permeability unit (a paleosol) 

that maintains the high water table conditions to support wet 

and mesic communities even on gentle slopes (fig. 4.20a). 

Low-permeability, buried soils also were shown to play an 

important role in supporting near-surface water and associated wetland ecosystems in California’s central valley (Rains 

and others 2006).

Stream channels are present in all meadow systems but 

vary in the degree to which they directly influence meadow water tables and vegetation. In some cases, the effects 

are negligible, but in others, they are highly significant. 

Reasons for this variation are differences in the path of the 

Figure 4.18. Groundwater and stream water level plots 

showing annual water level patterns as a percent of 

annual maximum water level in the Kingston 3 meadow. 

Annual hydrographs for all sites, except well 54S, show a 

relatively short period of rising levels and a much longer 

period of declining levels. At the stream and well sites 

33 and 87, about three-quarters of the annual rise occurs 

within one month.

80

100

0

20

40

60

60

80

100

 lower meadow

20

40

60

80

100

0

20

40

100

0

20

40

60

80

100

0

Water level as percent annual maximu

m

1/1/20052/1/20053/1/20054/1/20055/1/20056/1/20057/1/20058/1/20059/1/2005

12/1/2005

1/1/2006

0

20

40

60

80

upper meadow

10/1/200511/1/2005 Stream

101S

87D

54S

33D
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 61

Figure 4.19. Hydrologic features common to meadows. (a) springs; (b) groundwater seeps along 

channel sides; (c) artesian conditions (picture of flowing well); (d) perched water table, commonly 

characterized (as in this photo) by a wet meadow stream immediately adjacent to sage brush; (e) 

groundwater piping in fine sediments (see flow at arrow); and (f) artesian pipes: photo shows arm 

down muddy water flowing to surface from confined aquifer.

channel with respect to the meadow, the size of the channel, 

the nature of the subsurface materials, the interaction with 

groundwater, and the water source (groundwater, runoff, or 

both) (Chapter 5). Stream channels produced the deposits 

in the geologic past that created the hydrologic conditions 

necessary to support these meadows but do not necessarily 

control the current hydrologic state of the meadows. The location of meadows is explained by groundwater conditions, 

but that does not mean that streams are unimportant to the 

present or, especially, future status of meadows.

An important trait of the relationship of stream channels 

to meadow hydrology is whether the stream reach is being 

fed by groundwater (gaining) or is recharging groundwater 

(losing). In a gaining stream reach, the depth of the water 

table increases with distance from the stream, whereas the 

water table depth decreases with distance from a losing 

stream (figs. 4.10a and b). Riparian vegetation patterns can 

be used to infer if a stream reach is gaining or losing because groundwater-dependent plant communities can serve 

as a proxy for average depth to the groundwater table. At 

the Kingston 3 meadow, the plant communities became 

drier closer to the stream (fig. 4.21), indicating a gaining 

stream (an inference supported by groundwater well data). 

At the Corcoran meadow (fig. 4.20c), the plant communities 

became drier toward the margins of the valley indicating a 

losing system.

The significance of stream connection, or control, on the 

groundwater table can be assessed by comparing vegetation 

on either side of a stream. In Cottonwood Canyon, the creek 

has dry vegetation (sage brush) on one side and mesic vegetation (baltic rush) on the other side; this suggests that the 

groundwater flow direction is from the wetter to the drier 

side and, importantly, that stream incision has intercepted and 

lowered the groundwater table (fig. 4.20d). In this case, the 

stream may have contributed to some loss in the area of wet 

meadow complexes. Alternatively, some streams do not alter 

the groundwater flow patterns or table in the meadow, as reflected in the similar plant communities on both sides of the 

stream (Birch 1; fig. 4.20e). Although these streams have not 

yet lowered the groundwater table enough to cause shifts in 

plant community types, future stream incision may affect the 

groundwater table and plant communities.

Some channels are completely disconnected from the 

groundwater under most conditions as they do not support 

perennial streams. These channels, such as in lower Indian 

Valley, are typically larger than perennial spring channels 

(fig. 4.20e) and have developed to convey seasonal discharge 

typically associated with snowmelt runoff (fig. 4.20f). Most 

of the time, these channels have little affect on groundwater 

because the channel bed is well above the water table. When 

they do transmit runoff, they are sites of stream-focused 

groundwater recharge (Constantz and others 2007).
62 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Creation of new channels or enlargement of existing 

channels can partly or completely degrade the hydrologic 

framework necessary to support a meadow. Stream incision 

and subsequent channel adjustments can occur over a few 

years to decades, with subsequent effects on both water table 

depths and vegetation. Thus, an important consideration in 

evaluating the effects of streams on meadows is to determine 

whether the present-day stream is connected to the meadow 

and, if the stream is actively incising, how groundwater hydrology may change.

Springs, artesian conditions, and perched water tables in 

meadows of the central Great Basin indicate the presence 

of heterogeneous geologic materials that cause complex 

groundwater conditions. The typical meadow has a geologic 

setting with complex stratigraphy characterized by strongly 

contrasting hydraulic conductivities and high hydraulic gradients. Consequently, any changes in the meadow systems, 

whether by streams, people, or climate, are likely to result in 

a complex response that may vary from meadow to meadow 

or even within one meadow.

Approach for Assessing the 

Hydrologic Status of Meadows

A general assessment of the current status of meadows 

can be made based on the hydrogeologic setting, groundwater sources, the occurrence and effects of stream incision, and 

stream-subsurface water interactions. Table 3.2 illustrates the 

use of field indicators to characterize six meadow complexes 

that were evaluated in this study. Part of this assessment was 

based on using meadow vegetation patterns to interpret hydrologic characteristics. This approach was justified by the 

strong relationship between plant community type and depth 

to groundwater table (figs. 4.1a and b and 4.21; Allen-Diaz 

1991; Chambers and others 2004; Jewett and others 2004). In 

Figure 4.20. Photographs display 

meadow traits that reflect 

hydrologic characteristics and 

interrelationships between 

vegetation, hydrogeologic 

setting, and stream channel. 

(a) Wet meadow vegetation 

occurrence over slopes 

reflects a continuous blanket 

of near-surface, fine-grained 

sediments. This is comon in 

meadows with perched water 

tables. (b) Perched water 

table supporting wet meadow 

complex; yellow line marks a 

dry, groundwater well that is 

set in saturated meadow soils. 

(c) A losing stream is indicated 

by wet meadow species 

centered in the meadow with 

successively drier vegetation 

types away from the meadow 

axis. (d) Channel incision has 

caused a drop in the water 

table on left bank, as indicated 

by sage; because groundwater 

flow is from right to left, 

the water table on the right 

bank has been less affected. 

(e) Minor channel incision has 

had no significant effect on 

groundwater, as indicated by 

wet meadow vegetation on 

both banks. (f) Dry, bouldery 

channel is a seasonal runoff 

channel, mostly from snow 

melt, that has little relationship 

to the groundwater hydrology 

that supports the adjacent 

meadow.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 63

Figure 4.21. Maps of the Kingston 3 

meadow; downstream is south. (a) 

Depth of groundwater table below 

ground. (b) Plant communities. The 

depth to groundwater is shallowest at 

the valley sides and is deepest upvalley 

and adjacent to the stream. In general, 

the vegetation and depth to water table 

patterns are very similar, especially 

where the water table is most shallow.

some cases, interpretation of the relationship can be complicated by the lag in time for certain vegetation types to adjust 

to new hydrologic conditions. For this and other reasons, 

these assessment examples are not intended to substitute 

for field work with detailed observations. However, the 

examples demonstrate that important inferences regarding 

meadow processes can be made based on relatively simple 

field observations of vegetation patterns, stream characteristics, and the locations and types of springs.

Kingston 3 (table 4.2, trait E) is an example of a meadow 

system with complex stratigraphy and an incised stream, 

which have caused some meadow degradation. This meadow complex is located upstream of an alluvial fan and has 

a complex geologic setting and discontinuous stratigraphy 

with highly variable permeability. Stream incision has resulted in a drop in the water table adjacent to the stream and, as 

previously noted, the stream is gaining through much of the 

meadow. An increase in the depth to the water table adjacent 

to the stream has resulted in conversion from wet to mesic 

or dry meadow vegetation and, in some locations, encroachment of sagebrush (fig. 4.21). Wet meadow communities are 

associated with springs at the edges of the valley floor or 

side-valley alluvial fans, and artesian conditions are common. Although meadow vegetation in Kingston 3 appears 

largely adjusted to the current hydrologic regime, a lag in 

the response of long-lived riparian species like Juncus balticus and Iris missouriensis often occurs after stream incision 

(Chambers and others 2004). Also, because stream incision 

and subsequent channel adjustments can continue over years 

to decades (or longer), interpreting the relationships between 

water table depths and meadow vegetation requires accounting for the degree and activity of incision and determining 

the traits of the stream connection to the meadow hydrology.

In contrast to Kingston 3, Birch 1 (table 4.2, trait B) is 

a meadow system with simple stratigraphy that has been 

minimally degraded by stream incision. This meadow complex is located upvalley of a bedrock constriction and has 

largely continuous geologic units. The groundwater sources 

are from the upstream axial valley fill and side-valley areas that include numerous springs in the northeast portion 

of the meadow. The water table is largely perched in the 

down-valley portion of the meadow, which is capped by a 

low-permeability sediment/soil layer. The side-valley tributary is incised through much of the upper portion of the 

meadow and has caused a shift to drier meadow vegetation 

in that area. In contrast, despite over 1 m of incision in the 

main channel, there has been little affect on water table and 

vegetation, probably because of the perched water table.

Summary of Meadow Hydrologic 

Processes and Properties

The meadow complexes of the central Great Basin are 

groundwater-dependent ecosystems that, in some cases, 

are threatened by stream incision. In general, the headwater zones of watersheds that support meadow ecosystems 

are groundwater recharge areas, and groundwater recharge 

often occurs along the bed of losing streams primarily during seasonal snow melt. The meadows down-valley are 
64 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Table 4.2. Types of meadow complexes in the central Great Basin. The left column describes key hydrologic characteristics 

and the current relationship of the stream to meadow hydrology and vegetation patterns. The middle and right columns 

show a map of the plant communities in the meadow and an aerial photograph of the meadow, respectively.

Meadow Traits Meadow Plant Map Meadow Aerial Photograph

A. Simple, Not Degraded by BARLEY TRIB

Stream

Hydrogeologic Setting

• bedrock constriction

• continuous geologic units

Hydrology

• GW source is down valley 

• springs common in low 

permeability sediment layer

Stream Connections

• gaining

• incision has little effect on GW & N

vegetation patterns

BIRCH 1 B. Simple, Minimally Degraded by 

Stream

Hydrogeologic Setting

• bedrock constriction

50 m

100 m N

• continuous geologic units

Hydrology

• GW source is down & side valley 

• springs common in low 

permeability sediment layer

• perched GW table downmeadow

C. Simple, Stream Degraded BARLEY 1

Stream Connections

• gaining some; perched some

• >1 m of incision has little effect on 

GW & vegetation patterns

Hydrogeologic Setting

• downstream valley constriction & 

alluvial fan

Hydrology

• GW source is center and down 

valley

• artesian conditions and springs 

common

Stream Connections

• gaining

• incision has likely breached 

confined aquifer and has effected

riparian GW & vegetation patterns

N 50 m
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 65

Table 4.2 continued.

D. Complex; Minimally Degraded

by Stream

Hydrogeologic Setting

• Draped, old alluvial fans

• dominantly fine-grained geologic

CORCORAN 2 & 3

units

Hydrology

• GW source is down valley & center

valley upwelling

• perched water tables

Stream Connections

• losing, perched

• incision has had little effect on GW 100

N

• incision has had little effect on GW

& vegetation patterns

E. Complex, Stream Degraded

Hydrogeologic Setting

• upstream of alluvial fan

• complex geologic setting

KINGSTON 3

100 m

• discontinuous hydrogeologic units

with high variability in permeability

Hydrology

• GW source is valley sides and 

springs

• artesian conditions common

N

F. Complex, Degraded by Stream

Stream Connections

• gaining overall

• incision has effected riparian GW & 

vegetation patterns

SAN JUAN 1

100 m

N

Hydrogeologic Setting

• upstream of alluvial fan

• heterogeneous geologic units

Hydrology

• GW source mostly side valley 

• few springs

Stream Connections

• gaining 

• incision has altered GW & 

vegetation patterns

• GW support for most meadows on 

valley floor is lost

100 m

N

Legend: Plant Communities and Water Features

Upland Plants S Spring Stream tream Flow 

Mesic Dry Rose Shrub Aspen

Wet Mesic Shrub Dry Shrub Willow
66 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

discharge areas, although some stream channel reaches vary 

between gaining and losing over short distances or among 

seasons. The hydrologic regime exerts primary control on 

riparian meadow complexes and is strongly influenced by 

past and present geomorphic processes; biotic processes; 

and, in some cases, anthropogenic activities. There is a variety of specific geologic and geomorphic settings that create 

the shallow water tables necessary to support wet meadow 

vegetation, but a pervasive trait is the occurrence of lowpermeability, fine-grained sediments in the down-valley portion of the meadow.

In most meadows, the shallowest part of the water table 

is at the valley margins or in the central part of the valley 

floor and is not adjacent to a stream channel. Springs, artesian conditions, and perched water tables are common 

meadow features, especially in meadows underlain by 

complex stratigraphy. Stream- and groundwater levels vary 

during the growing season at daily scales, among seasons 

with the highest water tables during summer, and over years 

with weather patterns and climatic change. Meadow plant 

communities occur along gradients that are controlled by the 

depth of the water table and, thus, are key indicators of the 

hydrogeologic setting of meadows.

Stream channels are present in all meadows but vary in 

the degree that they influence meadow water tables and vegetation. Stream incision lowers groundwater tables; causes 

shifts in vegetation from wetter to drier species; changes 

groundwater flow paths; and, in extreme cases, causes permanent loss of meadow complexes. The specific response 

of the water table and vegetation to stream incision varies 

greatly with groundwater budgets, hydraulic conductivity of 

sediments, stream processes, and stratigraphy. The geomorphic and hydrologic characteristics of individual meadows 

vary considerably, and effective management and restoration 

requires a basic understanding of their hydrogeomorphic 

settings, especially the connectedness of groundwater systems with stream channels. Research on the meadows in the 

central Great Basin provides the necessary information for 

managers to assess the key hydrologic traits of meadow ecosystems and the relationships among the hydrogeomorphic 

setting, the stream channel, and the vegetation communities. 

For example, complex vegetation patterns along a stream 

channel likely indicate stratigraphic complexity where 

stream incision has significantly lowered the water table.

References

Allen-Diaz, Barbara H. 1991. Water table and plant species 

relationships in Sierra Nevada meadows. American Midland 

Naturalist. 126: 30-43.

Anderson, K.; Nelson, S.; Mayo, A.; Tingey, D. 2006. Interbasin 

flow revisited: the contribution of local recharge to highdischarge springs, Death Valley, CA. Journal of Hydrology. 

323: 276-302.

Ashley, G.M.; Goman, M.; Hover, V.; Owen, B.R.; Renaut, R.W.; 

Muasya, A.M. 2002. Artesian blister wetlands, a perennial water 

resource in the semi-arid rift valley of east Africa. Wetlands 22: 

686-695.

Castelli, R.M.; Chambers, J.C.; Tausch, R.J. 2000. Soil-plant 

relations along a soil-water gradient in Great Basin riparian 

meadows. Wetlands. 20: 251-266.

Chambers, J.C.; Miller, J.R., eds. 2004. Great Basin Riparian 

Ecosystems—Ecology, Management, and Restoration. Covello, 

CA: Island Press. 304 p.

Chambers, J.C.; Tausch, R.J.; Korfmacher, J.L.; Miller, J.R.; Jewett, 

D.G. 2004. Effects of geomorphic processes and hydrologic 

regimes on riparian vegetation. In: Chambers, J.C.; Miller, J.R., 

eds. Great Basin Riparian Ecosystems—Ecology, Management, 

and Restoration. Covelo, CA: Island Press: 196-231.

Constantz, J. 1998. Interaction between stream temperature, 

streamflow, and groundwater exchanges in alpine streams. 

Water Resources Research. 34: 1609-1615.

Constantz, J.; Adams, K.S.; Stonestrom, D.A. 2007. Overview of 

ground-water recharge study sites—Chapter C. In: Stonestrom, 

D.A.; Constantz, J.; Ferré, T.P.A.; Leake, S.A. Ground-water 

recharge in the arid and semiarid southwestern United States. 

U.S. Geological Survey Professional Paper. 1703: 61-82.

Devito, K.; Creed, I.; Gan, T.; Mendoza, C.; Petrone, R.; Silins, U.; 

Smerdon, B. 2005. A framework for broad-scale classification 

of hydrologic response units on the Boreal Plain: is topography 

the last thing to consider? Hydrological Processes. 19(8): 

1705-1714.

Dwire, K.A.; Kauffman, J.B.; Baham, J.E. 2006. Plant species 

distribution in relation to water-table depth and soil redox 

potential in montane riparian meadows. Wetlands. 26: 1.

Germanoski, D.; Miller, J.R. 2004. Basin sensitivity to channel 

incision in response to natural and anthropogenic disturbance. 

In: Chambers, J.C.; Miller, J.R., eds. Great Basin Riparian 

Ecosystems—Ecology, Management, and Restoration. Covello, 

CA: Island Press: 88-123.

Hunt, R.J.; Strand, M.; Walker, J.F. 2006. Measuring groundwater–

surface water interaction and its effect on wetland stream benthic 

productivity, Trout Lake watershed, northern Wisconsin, USA. 

Journal of Hydrology. 320: 370-384.

Jewett, D.G.; Lord, M.L.; Miller, J.R.; Chambers, J.C. 2004. 

Geomorphic and hydrologic controls on surface and subsurface 

flow regimes in riparian meadow ecosystems. In: Chambers, 

J.C.; Miller, J.R., eds. Great Basin Riparian Ecosystems—

Ecology, Management, and Restoration. Covello, CA: Island 

Press: 124-161.

Kalbus, E.; Reinstorf, E.; Schirmer, M. 2006. Measuring methods 

for groundwater-surface water interactions. Hydrology and 

Earth System Sciences Discussions. 10: 873-887.

Kleinhampl, F.J.; Ziony, J.I. 1985. Geology of northern Nye County, 

Nevada. Nevada Bureau of Mines and Geology Bulletin 99A. 

172 p.

Martin, D.W.; Chambers, J.C. 2001. Effects of water table, 

clipping, and species interactions on Carex nebrascensis and 

Poa pratensis in riparian meadows. Wetlands. 21: 422-430.

Maurer, D.K.; Lopes, T.J.; Medina, R.L.; Smith, J.L. 2004. 

Hydrogeology and hydrologic landscape regions of Nevada. 

U.S. Geological Survey Scientific Investigations Report 2004-

5131. 41 p.

Mifflin, M.D. 1988. Region 5, Great Basin. In: Back, W.; 

Rosenshein, J.S.; Seaber, P.R., eds. Hydrogeology, the geology 

of North America, Vol. O-2. Boulder, CO: Geological Society 

of America: 69-78.

Miller, J.R.; Germanoski, D.; Waltman, K.; Tausch, R.; Chambers, 

J. 2001. Influence of late Holocene hillslope processes and 

landforms on modern channel dynamics in upland watersheds 

of central Nevada. Geomorphology. 38: 373-391.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 67

Montgomery, D. 1999. Erosional processes at an abrupt channel 

head: implications for channel entrenchment and discontinuous 

gully formation. In: Darby, S.E.; Simon, A., eds. Incised River 

Channels. New York: John Wiley and Sons: 247-276.

Newman, B.D.; Vivoni, E.R.; Groffman, A.R. 2006. Surface watergroundwater interactions in semiarid drainages of the American 

southwest. Hydrological Processes. 20: 3371-3394.

Patten, D.T.; Rouse, L.; Stromberg, J.C. 2008. Isolated spring 

wetlands in the Great Basin and Mojave Deserts, USA: 

potential response of vegetation to groundwater withdrawal. 

Environmental Management. 41: 398-413.

Plume, R.W. 1996. Hydrogeologic framework of the Great Basin 

region of Nevada, Utah, and adjacent states. U.S. Geological 

Survey Professional Paper 1409-B. 64 p.

Prudic, D.E.; Niswonger, R.G.; Harrill, J.R.; Woods, J.L. 2007. 

Streambed infiltration and ground-water flow from the Trout 

Creek Drainage, an intermittent tributary to the Humboldt 

River, north-central Nevada—Chapter K. In: Stonestrom, D.A.; 

Constantz, J.; Ferré, T.P.A.; Leake, S.A., eds. Ground-water 

recharge in the arid and semiarid southwestern United States. 

U.S. Geological Survey Professional Paper. 1703: 313-351.

Rains, M.C.; Fogg, G.E.; Harter, T.; Dahlgren, R.A.; Williamson, 

R.J. 2006. The role of perched aquifers in hydrological 

connectivity and biogeochemical processes in vernal pool 

landscapes, Central Valley, California. Hydrological Processes. 

20: 1157-1175.

Stonestrom, D.A.; Constantz, J.; Ferré, T.P.A.; Leake, S.A. eds. 2007. 

Ground-water recharge in the arid and semiarid southwestern 

United States. U.S. Geological Survey Professional Paper 1703.

Sturtevant, K.A. 2007. Integrating multiple geophysical methods 

to analyze geologic controls of riparian meadow complexes, 

Central Great Basin, NV. Department of Geology, State 

University of New York at Buffalo. Thesis. 378 p.

Tennant, C.; Morgan, V.; Means, C.; Lord, M.L.; Jewett, D.G. 

2006. Hydrogeologic setting and characteristics of riparian 

meadow complexes in the mountains of central Nevada: a case 

study. Geological Society of America Abstracts with Programs 

Vol. 38. Paper 9-5.

Tooth, S.; McCarthy, T.S. 2007. Wetlands in drylands: 

geomorphological and sedimentological characteristics, with 

emphasis on examples from southern Africa. Progress in 

Physical Geography. 31(3): 3-41.

Wanty, R.B.; Winter, T.C. 2000. A simple device for measuring 

differences in hydraulic head between surface water and 

shallow ground water. U.S. Geological Survey Fact Sheet FS077-00. 2 p.

Weissmann, G.S.; Zhang, Y.; Fogg, G.E.; Mount, J.F. 2004. 

Influence of incised-valley-fill deposits on hydrogeology of a 

stream-dominated alluvial fan. Society of Sedimentary Geology 

Special Publication No. 80: 15-28.

Weixelman, D.A.; Zamudio, D.C.; Zamudio, K.A. 1996. Central 

Nevada riparian field guide. R4-ECOL-TP. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Intermountain 

Region.

Wilson, J.L.; Guan, H. 2004. Mountain-block hydrology and 

mountain-front recharge. In. Phillips, F.M.; Hogan, J.; Scanlon, 

B., eds. Groundwater recharge in a desert environment: the 

southwestern United States. Washington, DC: American 

Geophysical Union. 23 p.

Winter, T.C. 1999. Relation of streams, lakes, and wetlands to 

groundwater flow systems. Hydrogeology Journal. 7: 28-45.

Winter, T.C. 2001. The concept of hydrologic landscapes. Journal 

of American Water Resources Association. 37(2): 335-349.

Winter, T.C. ed. 2004. Hydrological, chemical, and biological 

characteristics of a prairie pothole wetland complex under 

highly variable climate conditions—the Cottonwood Lake area, 

east-central North Dakota. U.S. Geological Survey Professional 

Paper 1675. 109 p.

Winter, T.C. 2007. The role of ground water in generating 

streamflow in headwater areas and in maintaining base flow. 

Journal of the American Water Resources Association. 43(1): 

15-25.

Winter, T.C.; Harvey, J.W.; Franke, O.L.; Alley, W.M. 1998. Ground 

water and surface water: a single resource. U.S. Geological 

Survey Circular 1139.
68 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Introduction

I

nvestigations of geomorphic responses to natural and 

anthropogenic disturbances have revealed marked differences in the rate, magnitude, and nature by which different 

watersheds, or components of a given watershed, adjust to 

perturbations. These differences in response are often characterized using the concept of landform sensitivity. The term 

sensitivity has been defined by different investigators in different ways. For our purposes, it is defined after Brunsden 

and Thornes (1979) as “the likelihood that a given change in 

the controls of the system will produce a sensible, recognizable, and persistent response [in the landform of interest].” 

Inherent in this definition is the tendency for a stream, stream 

reach, or other landform to respond to an environmental disturbance by going through a period of disequilibrium until a 

new equilibrium state is achieved (Germanoski and Miller 

2004).

Conceptually, sensitivity is thought to involve several 

distinct components, two of which are (1) the propensity for 

change as governed by a set of driving and resisting forces, 

and (2) the capacity of the system to absorb change and remain in an equilibrium state (Downs and Gregory 1993). 

The rate of change also is important because while a stream 

or stream reach may be unstable (that is, in a disequilibrium 

state), it may exhibit a low propensity for change if the driving and resisting forces are such that adjustments occur at 

a slow rate. Germanoski and Miller (2004) show that for 

upland watersheds in central Nevada, each of these three 

components is important. For example, all of the examined 

basins were found to have incised in response to changes 

in climate and other perturbations following a major aggradational event between approximately 1980 and 2580 YBP. 

Watersheds such as Barley (Group 2, table 2.1) quickly 

adjusted to a new equilibrium state. This process involved 

rapid incision and profile adjustment with limited influence 

by side-valley fans. Group 2 channels now possess a low to 

moderate propensity for change because they have already 

attained a relatively stable state in comparison to other watersheds in the region. Presumably, they also are better able 

to absorb the potential effects of future disturbances. Other 

watersheds also exhibited a low to moderate sensitivity to 

change (Group 3, table 2.1). However, in contrast to Group 2 

basins, the likelihood of change in Group 3 basins is limited 

by the inability of the driving forces to overcome the forces 

that resist change at side-valley fans. This is in spite of the 

stair-step-like nature of the channel’s longitudinal profiles 

(caused by side-valley fans) that place the channels in an 

inherently unstable condition. Thus, the low to moderate 

sensitivity of the catchments in Group 3 is based on the very 

slow rate of change that occurs there.

The concept of sensitivity can be a powerful management tool as it provides insights into (1) the likelihood that 

a given river or meadow will respond to future disturbances; 

(2) the timing, duration, rate, and nature of the response; and 

(3) the potential for a given system to be stabilized or restored (Downs and Gregory 2004; Germanoski and Miller 

2004). The concept not only applies to geomorphology but 

also to system hydrology and biota. In this chapter, we examine the sensitivity of meadow complexes within upland 

basins of central Nevada in terms of site geomorphology and 

hydrology.

Geomorphic Sensitivity

Overview

The most important geomorphic processes within meadow ecosystems are incision, gully development and its 

associated headcut migration, groundwater sapping, and 

avulsion (Chapter 3). The rate, magnitude, and frequency 

of these processes are governed by numerous factors that 

must be considered in the analysis of meadow sensitivity to 

disturbance. Quantification of the combined effects of these 

processes for the purposes of creating predictive models of 

meadow sensitivity is a complicated and difficult task that 

must be undertaken on a meadow-by-meadow basis. These 

complications result from the following factors:

(1) The parameters that control meadow sensitivity function 

over different temporal and spatial scales. Incision, for 

instance, is closely tied to both sediment supply and the 

ability of flood flows to entrain and transport sediment. 

Thus, the geomorphic sensitivity of a meadow is closely 

related to the magnitude of runoff for a given frequency 

of event. The magnitude of runoff is associated with the 

amount and rate at which water can be funneled through 

the drainage network to a meadow and is influenced by 

factors like upstream basin area, relief, absolute elevation, 

ruggedness, drainage density, geology, and vegetation 

cover. If no other controls were present, meadow sensitivity would likely decrease from Group 1 to Group 

5 (table 2.1) and could be fully characterized by basin 

morphometry and its effects on precipitation-runoff relations. However, local factors including channel gradients, 

valley slope and widths, and localized groundwater discharge via springs and bank seepage may either increase 

or decrease the geomorphic sensitivity of meadows (see 

Chapter 5: Meadow Sensitivity to Natural 

and Anthropogenic Disturbance

Jerry R. Miller, Mark L. Lord, and Dru Germanoski
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 69

Chapters 3 and 4 for a discussion of the parameters that 

control these factors). Quantification of meadow sensitivity therefore requires the integration of processes that 

operate over spatial scales ranging from the entire basin 

to a channel cross section, a process that is conceptually 

and mathematically challenging.

(2) Sensitivity is controlled by the interaction of multiple 

reach-scale parameters that produce non-linear variations in process rates. Moreover, an increase or decrease 

in one variable may or may not have a strong influence 

on meadow sensitivity, depending on the nature of other 

parameters. Take, for instance, channel slope. A 2 percent 

increase in slope immediately downstream of a meadow 

(as is commonly found) tends to promote channel incision 

because higher gradients increase the erosive capability 

of flood flows, provided the other controlling factors are 

equal. However, in addition to slope, meadow sensitivity 

depends on such factors as bed material size and composition, water availability, and the frequency and magnitude 

of runoff events. Thus, meadow sensitivity cannot be determined on the basis of a single parameter, such as slope, 

but must include an analysis of multiple parameters and 

their interactions.

(3) Geomorphic processes that are of most importance in 

dictating meadow sensitivity are controlled by multiple 

mechanisms of landform change, which vary spatially 

over the meadow complex. For example, incision typically involves the grain-by-grain entrainment and transport 

of sediment as well as the development and migration of 

knickpoints or headcuts. The rate, magnitude, and nature 

of these processes vary along the meadows, in part, as a 

function of the underlying composition of the valley fill. 

Thus, quantitative predictions of future incision require 

detailed analyses of both mechanisms of incision and 

their interactions for a given material type, a particularly 

difficult task given that the sediments that underly meadows often change unpredictably.

(4) Meadows are subjected to abrupt shifts through time 

in the predominant geomorphic processes operating at 

the site. These process shifts cannot be easily predicted 

and are dependent on the timing and frequency of major 

hydrologic events. For example, unincised valley floors 

were observed to be initially dissected by the erosion of 

individual particles. As gully depth increased, there was 

often an abrupt change in the mechanism of incision from 

the entrainment of individual clasts to one of headcut 

migration controlled by groundwater-influenced, mass 

wasting processes. Additional shifts in process occurred 

during extreme flood events as groundwater-controlled 

headcut advancement was overridden by plunge pool 

development, headcut undermining and failure, and sediment removal by surface flows.

Given the above considerations, a quantitative assessment of meadow sensitivity to geomorphic change is 

challenging and requires a detailed analysis of the meadow 

system. However, as pointed out by Pilkey and Pilkey-Jarvis 

(2007), a qualitative understanding of the physical processes that are operating in a system often can be used to more 

effectively develop sound management strategies than quantitative models that may dramatically simplify the system or 

represent outliers of developed empirical trends.

Here, we highlight the primary factors that control meadow sensitivity and how a qualitative analysis of those factors 

(summarized in fig. 5.1 and table 5.1) can be used to predict 

the overall geomorphic sensitivity of meadows. The intent 

is not to develop a system that can replace the need for detailed geomorphic, hydrologic, or biotic analyses of a site. 

Rather, the goal is to provide a checklist of parameters that 

Large Change in

Elevation Across Fan 

Large Number of

Knickpoints 

Presences of

Overbank Gravels

& Avulusion

Groundwater Sapping

or Piping Features

Spring

Side-Valley

Fan

Smaller Bed Material

Through Fan

Steep Channel

Gradient 

Wet

Meadow

Figure 5.1. Factors 

that influence the 

geomorphic sensitivity of 

meadow complexes.
70 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Table 5.1. Factors influencing the geomorphic sensitivity of meadow systems.

Factors Factors Contributing to Sensitive Meadows

Sensitivity to incision, headcut migration, and groundwater sapping

Water availability

–Basin characteristics

–Groundwater discharge

Large basins, high relief, significant catchment area at high 

elevations (>3000 m), high ruggedness numbers and drainage 

densities, impermeable geological materials such as volcanic rocks

Numerous, high discharge springs feeding spring channels; upward 

flow gradients and artesian conditions

Flow convergence

–Valley width

–Anthropogenic structures

–Linear features

Narrow valleys that abruptly decrease in width down-valley 

causing groundwater and surface water convergence

Berms, dams, and other features that may lead to highly 

concentrated (channelized) flow on meadow surface

Cattle trails, roads, and other linear features that are devoid of 

vegetation and may capture and concentrate runoff 

Gradients

–Profile convexities

–Channel/valley floor

Occurrence of large convexities in long profile, which cause 

channel instabilities

Abrupt increases in channel or valley gradient, particularly through 

side-valley fans or other profile convexities 

Composition of valley fill

–Channel

–Undissected valley floors

Decrease in size of the channel bed material; an exception is the 

occurrence of highly resistant, clay-rich units commonly associated 

with paleosols

Valley fill composed of coarse sand and granules (grus) commonly 

associated with quartz monzonites and diorites; highly susceptible 

to erosion and groundwater sapping during rare, high-magnitude 

runoff events

Knickpoints/headcuts

–Occurrence

–Advancement mechanism

–Surface flow

–Groundwater; seepage

–Material composition

Frequent knickpoints or headcuts, particularly within meadow

Knickpoints or headcuts advancing by plunge-pool formation, 

undermining, and failure (most sensitive); groundwater driven mass 

wasting; sapping (seepage erosion), especially where valley fill is 

highly permeable

High probability of receiving surface flows; headcuts fed by 

shallow channels, roads, cattle trails, or other flow concentrators

Higher water tables and pore pressures; layered stratigraphy 

containing units of highly contrasting permeabilities

Sandy units with higher rates of headcut retreat; clay-rich units 

sensitive to groundwater piping and locally extensive surface 

incision of meadows
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 71

Table 5.1. Continued.

Factors Factors Contributing to Sensitive Meadows

Sensitivity to avulsion

Sediment availability

–Geomorphic instabilities

–Beaver dams

–Anthropogenic features

Numerous zones of upstream sediment influx to channel, including 

areas of mass wasting on hillslopes or trenching of side-valley fans

Numerous beaver dams, storage of large volumes of coarse (gravelsized) sediment

Anthropogenic features such as roads that may supply and funnel 

large volumes of sediment to channel; physical connectivity to 

channel is very important to sediment delivery

Gradients/transport capability Low-gradient zones, particularly where gradients decrease abruptly 

or where loss of water results in a loss of flow competence

Channel depths Shallow channels or zones characterized by distributary network as 

upstream channels enter meadows

Resistance to flow (roughness)

–Vegetation

–Structures

Increases in roughness associated with riparian or in-channel 

vegetation, particularly willows

Downstream increases in roughness associated with the 

construction of in-stream structures or other features

Spring channels Increases in frequency of spring channels which may capture 

overbank flood waters and promote channel capture

can be rapidly evaluated by land managers to identify the 

sensitivity of meadows that may or may not be suitable for 

treatments aimed at reducing the magnitude or rate at which 

a given geomorphic process negatively impacts a meadow. 

Those meadows where mitigating the impacts of geomorphic processes appears plausible in terms of their sensitivity 

to change will require more detailed assessments prior to 

the selection and implementation of any physical treatment 

method (e.g., the installation of in-stream structures, bank 

protection devices, or channel reconstructions).

Geomorphic Sensitivity to Incision

Longitudinal profiles along trunk valleys of upland watersheds show that axial streams possess a stair-step-like 

morphology in which low-gradient reaches form the step 

tread and high-gradient reaches form the riser (fig. 5.2). 

Meadows are frequently located along the low-gradient 

reaches or tread of these topographic steps (figs. 5.2). These 

steps or convexities in the profile form zones of instability 

that are prone to incision or gully development (Chapter 3). 

If a convexity exists, the meadow will likely incise at some 

time in the future. The potential magnitude of incision is 

dictated by the size (height) of the convexity, which is defined by the difference in elevation between the channel 

bed (or valley floor) and a uniformly sloping profile that is 

projected along the upstream channel bed (or valley floor) 

through the convexity at the downstream terminus (fig. 5.2). 

However, the existence of a convexity, even one of considerable size, does not necessarily guarantee that a meadow 

is highly sensitive with respect to channel bed lowering or 

meadow dissection. The typical runoff event may not be capable of entraining and transporting the material found along 

the channel bed, thereby inhibiting incision with small to 

moderate runoff events. In fact, the existence of the stepped 

profile indicates that incision has not occurred at a rapid rate 

Figure 5.2. Topographic 

convexity and 

definition of step 

height.
72 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

during approximately the past two millennia, at least where 

channel profiles are influenced by sediments deposited at the 

mouth of tributaries (Miller and others 2004). Thus, meadow 

sensitivity with respect to incision is strongly controlled by 

the magnitude and frequency of flood flows that are capable of eroding channel bed material, thereby elevating the 

stepped profile.

Incision is promoted by the ability of a basin to collect and effectively funnel water to meadows. Factors that 

influence the erosive capability of runoff events include 

basin elevation and the amount of snowpack accumulation 

in upland areas, and basin morphometric parameters such 

as size, relief, and ruggedness upstream of the meadow 

(Germanoski and Miller 2004). Once runoff water reaches 

the meadows, the erosive ability of water is modified by 

local conditions. Thus, while an abundant supply of water 

may be required for incision, it does not automatically indicate that incision will occur. Local factors that promote 

incision are: (1) narrow valleys that concentrate overland 

flood flows; (2) extensive subsurface discharge via springs 

and bank seepage; and (3) steep channel gradients, both 

within the meadow and along stream segments that are located immediately downstream of the meadow (Chapter 3). 

Incision along the downstream reach is important because 

lowering of the channel’s base level in these areas tends to 

produce localized incision that propagates upstream through 

the meadow complex (Chapter 3). The rate of incision, and 

therefore meadow sensitivity, also is strongly influenced by 

size of the channel bed material, which must be entrained 

and transported downstream. Put differently, it is influenced 

by the resistance of the channel bed to erosion.

The traditional and most widely used approach to assessing particle motion and, therefore, the potential for incision 

is based on the Shields (1936) criterion. The Shields criterion was developed using flume data and evaluates the shear 

stress near the channel bed that is required to get a particle 

into motion by moving it up and over its downstream neighbor. The method was constructed for particles of uniform 

size and yielded the expression:

	 τ c = ρdw S = 0.06 (ρ-ρs

)gD (5.1)

where τc is the critical shear stress at which particle motion 

begins; ρ and ρs are the densities of the fluid and particle, 

respectively; g is the gravitational constant; S is the slope 

of the water surface; and D is the diameter of the particle of 

interest (which is assumed to be similar to the surrounding 

particles).

More recent studies have shown that the Shields criterion is valid only for channels where the bed material is of 

nearly uniform size (Reid and Dunne 1996). In the case of 

gravel-bed rivers where bed sediment may range from sand 

to boulders, the equation requires modification for several 

reasons. First, larger, surrounding neighbors hide or protect 

smaller particles from the flow. These smaller particles require higher shear stresses than predicted by the original 

Shields equation in order to initiate motion. In contrast, particles that are larger than average project above surrounding 

clasts, are readily exposed to the flow, and require lower 

shear stresses for particle motion than predicted for uniform 

grains. Other factors of importance to gravel-bed rivers are 

the binding together of particles of differing size and shapes 

as they are packed into the stream bed, formation of bedforms, and development of vertical layers of differing grain 

size distributions in the channel bed (e.g., pavements and 

subpavements). At present, there is no consensus as to the 

degree of reduction in shear stress that occurs in gravel-bed 

rivers (or streams) (Reid and Dunne 1996). A wide range of 

equations has been developed to describe the initial motion 

of large particles (table 5.2). The differences among these 

equations are partly related to differences in the datasets 

used to create them and the definitions of initiation of motion and shear stress (Reid and Dunne 1996).

One way of using the equations (table 5.2) to assess the 

probability of incision is to estimate the percent of the channel bed that is likely to be mobilized at a given shear stress. 

The shear stress required to transport particles that comprise 

different percentages of the pavement can be calculated using the various equations shown in table 5.2 and plotted in 

figure 5.3 for the Snoqualmie River, Washington (which has 

median particle sizes of 56 and 17 mm in the pavement and 

subpavement, respectively) (Reid and Dunne 1996). These 

curves can then be compared to the shear stresses that are 

likely for varying flow depths within the channel. Changes 

in shear stress as a function of flow depth can be easily estimated using the equation: 

τ = γRS (5.2)

where γ is the specific weight of the fluid, R is the hydraulic 

radius of the channel, and S is the slope of the water surface. An advantage of this simplified approach is that data 

required for these calculations can be easily collected during 

a single visit to the site.

Given the approximate nature of the estimates of shear 

stress required to initiate motion by the equations in table 

5.2, predictions of particle entrainment and the potential 

for channel bed incision must be used with a strong degree of skepticism. The probability of incision is further 

complicated by the presence and advancement of knickpoints. Nevertheless, this approach (which determines the 

likelihood for particle entrainment for a given set of flow 

conditions will provide valuable insight into whether the bed 

material exhibits a low, moderate, or high degree of mobility. It may be particularly useful to apply these equations to 

large clasts found along the relatively high-gradient reaches 

of the channel steps to determine if particle entrainment of 

the materials controlling the local base level is likely.

Assessment of meadow sensitivity to incision by means 

of knickpoint or headcut migration is a more difficult task. 

Meadow development is highly variable from basin to basin 

and depends on both surface and groundwater conditions. 

The spatial distribution of headcuts shows that they tend to 

develop in areas of steep valley gradients, abundant water, 

and concentrated flow. These parameters often coincide 

along reaches of the valley floor that are prone to incise by 

means of knickpoint or headcut advancement. For example, 

many meadows occur on wide segments of the valley that 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 73

are characterized by low gradients (Chapter 3). During flood 

events, overland flows are concentrated by a reduction in 

valley width and are augmented by groundwater discharge. 

In addition, the erosive capability of the flow is enhanced 

by increases in gradient, thereby creating the ideal situation 

for gully/headcut formation. Once produced, the headcuts 

have the potential to migrate upvalley into the meadow system. Thus, variations in valley width, gradients, and zones of 

groundwater discharge are important factors that influence 

the degree of channel incision within the meadows.

The existence of a knickpoint or headcut indicates that the 

channel or valley floor is unstable and subject to entrenchment. However, a knickpoint or headcut does not necessarily 

mean that the meadow is highly sensitive to incision as these 

features may not migrate upstream at a significant rate (that 

is, within 100 to 102 years). Insights concerning the rates 

of knickpoint or headcut migration into and/or through a 

meadow can be obtained by examining (1) the source and 

availability of water to the feature and (2) the processes 

through which the features advance upvalley (Chapter 3). 

For knickpoints within a well-defined channel of a meadow 

complex, field surveys demonstrated that the primary mechanism of advancement is by means of knickpoint retreat 

associated with plunge pool formation, material undercutting, and failure of the knickpoint face. When combined 

with a concentrated and continuous supply of water from upstream, the knickpoints generally move quickly through the 

meadow (as in the case of Kingston 3 meadow, Chapter 3) 

unless migration is hindered by dense resistant roots, such as 

those associated with willows (as is the case in Birch Creek; 

fig. 1.7). Thus, where these types of knickpoints exist, meadows are moderately to highly sensitive to incision through 

continued knickpoint migration.

Rates of headcut migration into previously undissected 

meadows are more variable, both between meadows and 

through time at a given meadow. Although quantitative 

data on rates of migration are limited, they range from a 

less than 1 m per year to tens of meters per year during high 

Table 5.2. Selected equations used to predict the initiation of motion. Critical shear stress (τc in dynes/cm2) is 

calculated for individual particles of size Di

 (cm) positioned within the channel bed material with a median grain 

diameter (D50, in cm) for geometric mean diameter (Dg, in cm). Modified from Reid and Dunne (1996).

Reference Equation Definition of Motion1

Shields (1936) τc = 0.056 (ρs-ρ)gDi

Miller and others (1977) τc = 0.045 (ρs-ρ)gDi

Parker and others (1982) τc = 0.09 (ρs-ρ)gD50 Bedload

Diplas (1987) τc

 = 0.087 (ρs-ρ)gDi

0.06D500.94 Bedload

Parker (1990)2 τc

 = τrg (ρs-ρ)gDi

0.10D500.90 Bedload

Komar (1987)3 τc

 = 0.045 (ρs-ρ)gDi

0.35D500.65 Clast

Andrews (1983) τc

 = 0.083 (ρs-ρ)gDi

0.13D500.87 Clast

Ashworth and Ferguson (1989) τc

 = 0.072 (ρs-ρ)gDi

0.35D500.65

τc = 0.054 (ρs-ρ)gDi

0.33D500.67

τc = 0.087 (ρs-ρ)gDi

0.08D50

0.92

Bedload

Bedload

Bedload

Komar and Carling (1991) τc

 = 0.059 (ρs-ρ)gDi

0.36D500.64

τc = 0.039 (ρs-ρ)gDi

0.13D500.82

Clast

Clast

Costa (1983) τc

 = 26.6Di

1.21 Deposit

Williams (1983) τc

 = 12.9Di

1.34 Deposit

1

 Method with which particle motion is defined; Bedload—initiation of motion defined by occurrence of a small but finite amount 

of transport; Clast—initiation of motion defined by largest particle moving at a given τ; Deposit—initiation of motion defined 

from the largest particles deposited during an event with a given τ at crest stage. 2

 Dg is the surface geometric mean diameter of the clast, which is calculated as lnDg = Σ FiLnDi, where Fi is the ith particles size 

class and has a geometric mean of Di

, and τrg = 0.836(Dg/D50sub)-0.905 is the reference dimensionless shear stress for Dg. 3

 Equation based on surface grain parameter but used for subsurface.

Figure. 5.3. Percent of channel bed clasts that are mobile, 

as calculated using equations in table 5.2. Data for 

Snoqualmie River, Washington. Figure from Reid and 

Dunne (1996).
74 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

magnitude events such as occurred in 1982 and 1983. In 

general, headcut retreat that is driven by seepage erosion or 

groundwater-related mass wasting processes (as observed in 

Indian Valley and Corcoran Canyon, fig. 1.7) proceeds rather 

slowly—less than approximately 1 m per year. These rates 

are unlikely to change significantly from one runoff year 

to the next if the available surface water is limited due to a 

small upstream catchment area of low relief or altitude or a 

wide valley that is incapable of concentrating flow. For example, in Cahill Canyon (fig. 1.7), a low-relief headcut is 

advancing into a small meadow located near the headwaters 

of the drainage. Although the headcut is positioned along a 

slightly oversteepened reach of the valley floor and is developed in fine-grained sediments, the likelihood of rapid 

advancement is small because both surface and groundwater flow to the headcut is limited. In contrast, headcut 

advancement by means of plunge pool development and 

failure associated with overland flows can occur much 

more rapidly. In Indian Valley, for example, the diversion 

and concentration of flow onto a previously undissected 

portion of the valley floor led to extremely high rates of 

upstream headcut migration—several to tens of meters per 

year—between 1961 and 1982 (fig. 3.15). 

The mechanisms of headcut migration can change 

through time. Temporal changes are associated with rare, 

high magnitude runoff events and anthropogenic activities that concentrate flow on the valley floor; remove the 

existing vegetation; and, reduce the erosive resistance of 

the valley fill. Examples of anthropogenic activities include development of roads, drainage diversions, or berms. 

Livestock, which often produce trails capable of concentrating flow and funneling it to the top of headcuts, may 

also exacerbate upvalley headcut migration (for example, 

Indian Valley, fig. 3.19).

A rapid and effective method of assessing meadow sensitivity to headcut advancement is to determine the rates 

of upstream headcut migration by comparing the position of headcuts on aerial photographs of differing ages. 

If multiple sets of photos are examined, the average rates 

of migration can be determined for the period bracketed by 

the aerial photographs. The estimated rates, determined for 

multiple photographic pairs, can then be compared to local 

precipitation records to determine rates of advancement associated with the period’s precipitation/runoff magnitudes. 

In addition, it may be possible to obtain a qualitative understanding of the frequency with which flood flows cause 

rapid upstream headcut migration. The analysis also can 

provide insight into the portions of the meadow that may 

be sensitive to current or future incision by headcut migration and into the causes of instability such as diversion of 

surface flows to a new area of the meadow or valley floor.

Meadows that are extremely sensitive to incision by 

groundwater sapping processes are those that are underlain 

by highly permeable sediments such as the grus-dominated 

valley fill in Marshall Canyon. Erosion of small, discontinuous channels during low to moderate runoff events 

may lead to a shift in the dominate erosion process to 

groundwater sapping during major floods, particularly 

where flows from tributaries and springs converge. As a 

result, headcuts can form and migrate tens of meters in a 

few days (fig. 3.7), making these meadows extremely sensitive to disturbance (see discussion on Marshall Canyon, 

Chapter 3).

Geomorphic Sensitivity to Avulsion

The geomorphic processes that affect wet meadow 

ecosystems are incision, localized aggradation, and avulsion (Chapter 3). Avulsion events can significantly alter 

meadow complexes by (1) delivering coarse gravel-sized 

materials to the valley floor; (2) creating high, linear ridges 

within the meadow that exhibit relatively deep water tables; and (3) leading to development and enlargement of 

new channels, which are often prone to incision and localized groundwater lowering (fig. 3.22). 

Avulsion is caused by the interaction of several factors 

that lead to a threshold crossing event. While it is extremely difficult to predict the probability that a meadow will 

experience an avulsion during a given period, the primary controlling factors can be evaluated to assess whether 

a meadow has a high, moderate, or low risk of channel 

shifting and abandonment. For example, avulsion within a 

meadow is primarily driven by the rapid influx or release 

of coarse sediment from an upstream reach and the subsequent deposition of that sediment within the channel as 

it traverses the meadow complex. Thus, the likelihood of 

avulsion is closely tied to upstream sediment sources, which 

may periodically deliver large quantities of coarse material to the drainage network. Without these sources and the 

influx of coarse sediment, avulsion will not occur. Thus, 

any evaluation of the future stability of a meadow should 

involve the identification of upstream sediment supplies. 

Potential supplies are: (1) beaver dams and ponds that store 

large volumes of course debris that can be released upon 

dam failure; (2) unstable hillslopes that are characterized 

by mass wasting scars, which can deliver sediment directly 

to the channel; (3) steep roads that cross or lie immediately adjacent to the channel and have the potential to be 

extensively gullied; and (4) steep side-valley alluvial fans 

that are or may become trenched, thereby supplying sediment to the drainage system. Each of these sources can be 

mapped on topographic sheets, and their potential to supply debris to the drainage network can be evaluated.

The influx of coarse sediment to the channel does not 

always lead to avulsion as the material may be transported 

downstream through the meadow complex. It is therefore 

necessary to examine the local factors that may lead to avulsion within the meadow. One factor that promotes avulsion 

is a reduction in the capacity of the channel to contain moderate to large flood events. Decreases in channel capacity 

are frequently related to stream bed aggradation produced 

by a decline in channel gradient near upstream meadow 

segments. Reductions in stream gradients are common 

(fig. 3.21) and result in a lowering of both channel capacity 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 75

and competence. Other factors that lead to aggradation 

are an increase in roughness (resistance to flow) caused 

by riparian vegetation, particularly willows, and in-stream 

obstructions to flow, including erosion control structures.

Ongoing stream aggradation can be identified along 

meadow channels in the form of longitudinal bars on terraces and other low-lying surfaces next to the stream 

(fig. 3.21) or as thick accumulations of gravel within the 

channel bed, which are often accompanied by reductions in 

channel depth. Whether or not these zones of aggradation 

ultimately result in avulsion depends on the loss in channel capacity and depth and the nature of adjacent meadow 

topography. In a review of the causes of avulsion, Jones 

and Schumm (1999) found that avulsion was promoted by 

steep floodplain gradients in comparison to the pre-avulsion channel. In central Nevada, meadow surfaces are most 

likely to exhibit gradients that are greater than those of the 

channel in areas where the stream is highly sinuous. Highly 

sinuous channels exhibit a higher likelihood of avulsion 

than straight channels, provided other controlling factors 

are similar. Another control on the likelihood for avulsion 

is the occurrence of linear depressions, which are often associated with paleochannels within the meadow complex. 

These depressions may be intersected by the modern channel. Where they intersect, channel depths and, therefore, 

capacities are relatively low, allowing flood waters to spill 

over into the depression before inundating other portions 

of the meadow’s surface. Spring channels also serve as 

preferential routes of flood flow. The fine-grained nature of 

sediments at the surface of depressions and lining the perimeter of spring channels often allows them to be scoured, 

producing topographic conduits with a bed below the adjacent channel floor. As a result of the differing channel 

bed elevations, the newly scoured channel can eventually 

capture the entire upstream flow. For example, in the Birch 

Creek 1 meadow (fig. 1.7), aggradation and a loss in channel capacity presumably led to a recent increase in overbank 

flooding. The flood flows were concentrated in the spring 

channel, which over time incised and widened to become 

the new truck channel, leaving the aggraded reach as an 

abandoned segment. Localized aggradation of an unincised 

reach farther upstream and subsequent willow colonization 

suggests that the meadow remains highly sensitive to avulsion processes because (1) channel capacity is likely to be 

decreased by the deposition of coarse-sediment within the 

channel, resulting in overbank flows, and (2) the overbank 

flows may be routed into existing spring channels.

Man-made structures often increase hydraulic roughness and can, therefore, lead to stream bed aggradation and 

a loss in channel capacity if there is a supply of coarse 

sediment to the reach. If the loss in channel capacity is significant, the result may be avulsion. Thus, care must be 

taken to ensure that structures that are used to inhibit channel incision while coarse sediment influx is limited do not 

lead to aggradation and avulsion during large events when 

bedload transport rates are high. In other words, in-stream 

structures or other forms of bed and bank modifications 

may simply shift the zone of incision to a new location. 

Possible approaches to limit the effects of these structures are to design structures to fail during high magnitude 

events, thereby reducing their ability to cause intense, localized aggradation, and to restrict their use where coarse 

sediment is likely to be input to the meadow.

Geomorphic Sensitivity Summary

Numerous factors promote and resist geomorphic change 

within meadow complexes (table 5.1). The challenge for 

land managers is to determine whether interactions of these 

factors at a particular meadow have produced a system that 

is relatively stable and has the potential to be effectively 

managed or a system that is highly sensitive to change. 

Determining outcomes of interacting factors is difficult. 

Nevertheless, an evaluation of whether the factors (table 

5.1) contribute to meadows of high, moderate, or low sensitivity informs the likelihood of future change. Take, for 

example, a meadow characterized by a large, upstream 

basin; a rapidly narrowing downstream valley; and a channel that is characterized by a pronounced convexity, steep 

downstream gradients, relatively small bed material, and 

significant groundwater influx. The combined effects of 

these factors will likely produce a meadow that is highly 

sensitive to geomorphic change. Thus, a simple checklist 

evaluation of the primary controlling factors can be used 

to rank the sensitivity of upland meadows to incision or 

avulsion. This evaluation can be used to decide if it is necessary to conduct more detailed geomorphic studies of the 

site with the intent of developing management options or if 

resources would be more wisely spent on another meadow 

system.

Hydrologic Sensitivity

Overview

The concept of hydrologic sensitivity of meadows is 

used here in a manner similar to geomorphic sensitivity. 

Hydrologic sensitivity describes the propensity for changes 

in groundwater conditions that result in a decline in the 

water table depth. Because montane meadow complexes 

in the central Great Basin are groundwater-dependent 

ecosystems, the typical response is a shift in vegetation 

patterns from wet and mesic meadow community types to 

drier types over part or all of the meadow (Chambers and 

others 2004). The drivers of change within meadows, in 

most cases, are related to the processes of channel incision, 

headcut migration, or avulsion. Drivers of change external to meadows include climatic change and disruption 

of recharge, routing, or connectivity of source waters that 

support meadows. 

The general relationship between stream incision, lowering 

of the water table, and vegetation shifts have been described 

for arid and semi-arid regions (Stromberg and others 1996; 

Chambers and Miller 2004; Webb and Leake 2006). In some 

studies, linkages between streams, groundwater levels, and 
76 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

vegetation have been well enough established to develop 

models to predict vegetation shifts in response to changes in 

hydrology (Schilling and others 2004; Loheide and Gorelick 

2007). However, in many places, hydrogeologic complexity prevents effective use of quantitative models. Variables 

that limit the value of quantitative models include lack of 

stratigraphic data, partial penetration of streams into aquifers, transient hydrologic conditions, and characterization of 

stream bed materials related to exchange of groundwater and 

stream water (Woessner 2000; Sophocleous 2002; Vidon and 

Hill 2004; Loheide and others 2009). In some cases, such as 

in major restoration projects, money- and time-intensive efforts may be warranted to fully evaluate meadow conditions 

in order to develop accurate quantitative models. However, 

for most areas, these intensive efforts are seldom feasible. 

Alternatively, conceptual models based on a process-based 

understanding can be effective research and management 

tools (Woessner 2000; Vidon and Hill 2004; Loheide and 

others 2009).

Hydrologic Processes and the 

Factors Controlling Sensitivity

Our study of 56 riparian meadows has provided information on meadow processes, linkages between biotic 

and abiotic systems, and landscape controls. In this section, qualitative factors controlling hydrologic sensitivity 

are used to assess meadow conditions. The key controls on 

hydrologic sensitivity are: (1) based on conceptual models 

that have been validated through our research, (2) observed 

in other riparian systems, and (3) founded on established 

principles of hydrogeology.

The individual hydrologic characteristics of meadows 

are wide ranging, but sufficient generalizations can be 

made to provide a foundation for analyzing hydrologic 

sensitivity. Springs, artesian conditions, and perched water 

tables in meadows of the central Great Basin indicate the 

presence of heterogeneous geologic materials and complex 

groundwater conditions. The typical meadow has a complex 

geologic setting with complex stratigraphy characterized 

by strongly contrasting hydraulic conductivities and high 

hydraulic gradients. The variability in spatial and temporal hydrologic patterns, such as water levels and pathways, 

also is due to natural climate and weather cycles and the 

combined influences of mixed groundwater sources. The 

nature of the connection between groundwater and surface 

water (Chapter 4) is an especially strong determinant in 

how the water table and, therefore, vegetation types respond to stream incision. Different parts of meadows have 

different hydrologic patterns, and changes that are external 

to the meadow in the recharge regions of the source waters 

also affect meadow hydrology. Thus, evaluation of meadow sensitivity requires an understanding of each meadow’s 

hydrologic, geomorphic, and vegetation characteristics.

Four groups of factors are used to assess hydrologic 

sensitivity: (1) meadow hydrology, including groundwater 

and stream water interactions; (2) meadow stratigraphy; 

(3) geomorphic processes and stratigraphic setting; and (4) 

source waters (table 5.3).

Meadow Hydrology: Groundwater-Stream 

Water Interactions

The connection of surface water to groundwater along 

stream channels is recognized for its importance in nutrient 

transfer and other aspects of stream ecology (e.g., Hayashi 

and Rosenberry 2002; Sophocleous 2002). The term “connection” is used to describe if and how often stream water is 

connected to groundwater along the channel perimeter. The 

type and nature of the channel connection to the groundwater 

table directly affects the kind and magnitude of groundwater 

responses (table 5.3a.1; fig. 5.4). Several connection types 

are recognized: (1) continuous, which requires perennial 

stream flow and a shallow water table; (2) intermittent or 

ephemeral, where stream flow or seasonal variations in water table elevation are needed for a connection; and (3) not 

connected under typical climatic conditions, where stream 

flows are short-lived and groundwater tables are deep (e.g., 

Lerner 2003). The connection type does not indicate directly 

whether the stream segment is gaining or losing.

Channels that are created and fed only by springs, not 

runoff, tend to be small and do not significantly disrupt the 

water table geometry (fig. 5.4a). Spring-fed channels tend to 

have lower width to depth ratios and less variable discharge 

than runoff-dominated channels (Griffiths and others 2008). 

Channels that convey runoff are larger and, in general, much 

more dynamic than spring-fed channels. In some places, 

channels that convey runoff are perennial, whereas in others, they are ephemeral or intermittent, flowing only during 

periods of high runoff. Perennial channels that convey runoff and groundwater baseflow intersect the water table, are 

typically gaining, and cause subsurface flow convergence 

that results in a lower water table adjacent to the channel 

(fig. 5.4c). Stream incision of these channels causes further declines in the water table and, consequently, can lead 

to shifts in plant community types. This response is well 

documented (see Chambers and others 2004; Shilling and 

others 2004; Loheide and Gorelick 2007; Loheide and others 

2009). Intermittent and ephemeral runoff channels are not 

connected to the water table for most of the year, and when 

they do convey flow, they are losing stream segments (fig. 

5.4b). Incision of these channels will not cause a decline in 

the water table unless the channel reaches a depth where it 

intersects the water table.

Perennial channels that convey runoff are typically 

gaining streams. However, some of the perennial stream 

segments in meadows are losing, even though they are connected to the groundwater and convey some runoff (table 

5.3a.2). These stream segments can support meadow complexes as indicated by the occurrence of wet or mesic plant 

communities adjacent to the channel and drier plant communities at distance from the channel (fig. 5.5). Where streams 

are the primary source of water to meadows, stream incision has the potential to cause a complete loss of shallow 

groundwater necessary to support wet and mesic vegetation. 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 77

Table 5.3. Factors influencing the hydrologic sensitivity of meadow systems.

Factors Factors Contributing to High Sensitivity of Meadows 

A. Sensitivity related to meadow hydrology: groundwater-stream water interaction

(1) Stream channel connection to 

groundwater

fig. 5.4

Stream channels that intersect groundwater table and are incised deeply 

enough to cause groundwater flow convergence to channel, typically 

reflected by vegetation patterns adjacent to channel

(2) Gaining or losing

fig. 5.5

Losing streams that are primary water source for meadows, especially in 

perched systems, because further incision will increase depth of groundwater 

table in wettest part of meadow and may cut off recharge of shallow, perched 

system

(3) Relation of groundwater flow 

direction to position of new channel

fig. 5.6

Incision of valley floor on upgradient side of flow will cause drop in 

groundwater table across remainder of valley floor.

B. Sensitivity related to meadow stratigraphy

(1) Hydraulic conductivity of meadow 

sediments adjacent to stream channel

fig. 5.7

Incision of high hydraulic conductivity materials will cause more of a 

widespread drop in the water table than finer-grained materials.

(2) Key hydrostratigraphic units and 

stratigraphic complexity

figs. 5.8 and 5.9

Areas with complex stratigraphy, especially with perched and artesian 

conditions, are most likely to change significantly (unpredictably) with 

incision or new channels. In extreme cases, incision of a key confining layer 

may cause widespread drop in water table and loss of entire wet meadow 

complex.

(3) Resistance of stratigraphic units to 

erosion

fig. 5.10

Pervasive fine-grained, noncohesive sediments are more prone to erosion, 

causing lowering of water table

C. Sensitivity related to geomorphic processes and stratigraphic setting

Hydrogeomorphic condition after 

incision or new channels

fig. 5.11

Incision or new channels that do not create new, lower-elevation meadow 

complexes result in a greater net loss of meadow area.

D. Sensitivity related to source waters

Source waters and their connectivity 

to meadows

figs. 5.12 and 3.18

Meadows supported by source waters with limited recharge areas, a limited 

recharge period, and variable connectivity to the meadow hydrology are 

susceptible to change due to upland changes in land cover, climate, and 

stream channels. 

The sensitivity of this type of system is well documented 

in meadows 1 through 5 in Corcoran Canyon (figs. 1.7 and 

4.2), which occur on step-shaped profiles. The string of five 

meadows are separated by non-meadow zones, where the 

stream channel is incised to depths greater than 0.5 m (table 

4.2d).

The hydrologic sensitivity of a meadow can be directly 

influenced by the geomorphic sensitivity, especially when 

new channels are formed, such as by headcut migration or 

avulsion. The locations of new channels with respect to the 

direction of groundwater flow along a valley floor can have 

marked effects on groundwater. In some cases, new channels can capture all shallow groundwater flow (table 5.3a.3). 

Capture of shallow groundwater flow is most pronounced 

where orientation of the stream channel is perpendicular to 

the direction of groundwater flow (fig. 5.6). This aspect of 

hydrologic sensitivity is seen in Indian Valley, where a network of headcut trenches, driven by groundwater sapping, 

migrated into a previously wet meadow complex with no 

channels. As shown in fig. 5.6d, wet to mesic plant communities persist across much of the valley floor where a new 

channel trench developed on the downgradient side of the 

valley with respect to groundwater flow (see the yellow arrow). This is in contrast to another segment of the valley 

floor that is now void of wet-mesic plant communities, 

where headcut migration on the upgradient side of the valley 
78 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Figure 5.4. Diagrams at top depict three broad types of connections between stream channels and groundwater. These 

diagrams are generalized to show general topography, groundwater table and flow, wet vegetation, and dry vegetation. 

The photographs below show the same channel types, indicated by the corresponding letter, in the study meadows. The 

left diagram (a) shows a spring-fed channel and (b) shows an intermittent runoff channel. Though the spring channel 

intersects the groundwater table, it does not significantly alter the groundwater table. The runoff channel (b) does 

not cause lowering of the groundwater table. Gaining, perennial meadow streams, as shown in (c), are connected to 

groundwater and cause flow convergence and a decline in water table.

Figure 5.5. Diagrams at the top 

depict likely response of a 

gaining stream and a losing 

stream channel to incision. 

(a) Incision of a gaining stream, 

where sustaining water of the 

meadow complex is not stream 

water, will result in a limited 

water table drop adjacent to 

the channel (a2). (b) Incision 

of a losing stream, where the 

stream water supports a meadow 

complex, may result in loss of 

wet meadow complex (b2). 

Plant community patterns in 

Kingston 3 and Corcoran reflect 

stream type, as discussed in 

Chapter 5, with wet to mesic 

plants at valley margins in a 

gaining system (a3) and adjacent 

to the stream in a losing system 

(b3). Plant community types 

are A—Wet Meadow (example, 

Nebraska sedge), B—Mesic 

Meadow (example, Baltic rush), 

C—Dry Meadow (example, 

Nevada Blue Grass), D—Mix: 

Dry and Sage Meadow, and 

E—Sage Meadow. Inset 

photograph (b3) shows a site 

with sagebrush encroachment 

into a former wet meadow 

following incision.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 79

intercepted and lowered the groundwater table across the entire valley floor (see the red arrow). In the meadows of the 

central Great Basin, it is common for groundwater flow directions to have a strong cross-valley component, especially 

where side-valley alluvial fans are present (e.g., Kingston 

3 meadow). With respect to sensitivity and groundwater, 

special attention should be given to potential new channels 

created either by headcut migration or avulsion on the upgradient side of the valley.

Meadow Stratigraphy

The distinction between meadow hydrologic and stratigraphic controls on sensitivity is somewhat arbitrary 

because the factors are interdependent. The characteristics 

of a stratigraphic unit or sequence either support the shallow 

groundwater system or determine how meadow subsurface 

hydrology responds to channel incision. Hydraulic conductivity of the sediments surrounding the stream channel (table 

5.3b.1) can influence the rate and extent of incision. Incision 

by a stream that is connected to groundwater (i.e., intersecting the water table) into a coarser-grained, high hydraulic 

conductivity stratigraphic unit will cause a more extensive 

drop in the water table than incision into a finer-grained 

unit (figs. 5.7a and b) (Vidon and Hill 2006). Immediately 

adjacent to the stream channel, however, the amount of 

water table drop may be greater in finer-grained material 

than in coarser-grained material. The principles that underlie this phenomenon are analogous to those used to predict 

the response of the groundwater table to a pumping well. 

Aquifer hydraulic conductivity, thickness, and porosity are 

key factors that control the amount and extent of drawdown 

Figure 5.6. (a) New channel incision on unincised valley floor on the down-gradient side of groundwater flow (b) will cause a 

drop in the groundwater table across only a small portion of valley floor with a minimum loss of wet meadow complex area. 

In Indian Valley (d—yellow arrow), groundwater wells (A, B, C, D, and E) show cross-valley flow is intercepted by a trench 

that recently migrated headward due to groundwater sapping, which resulted in a drop of the groundwater table in excess of 

2 m (e). Alternatively, (c) channel incision on the upgradient side of the valley floor will cause a water table drop across the 

remainder of the valley floor within a large loss of wet meadow complex area. The valley floor is all sage meadow in Indian 

Valley (d) where trenches have intercepted almost all shallow groundwater flow (d—red arrow).
80 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

(Freeze and Cherry 1979). The direct role of hydraulic conductivity on the decline of the water table in response to 

incision is apparent at the Kingston 3 meadow (Lord and 

others 2007). Stream incision caused a widespread drop in 

the water table where it intersected a sandy gravel avulsion 

deposit (fig. 5.7c), and it caused encroachment of sagebrush. 

Finer-grained sediments on the opposite side of the stream 

prevented a wide-spread drop in the water table.

The stratigraphy of most meadow systems is complex, 

which largely explains why perched water tables, springs, 

and artesian conditions are so common (Chapter 4). In some 

cases, the shallow meadow water table is supported by a 

single hydrostratigraphic unit, typically a low-permeability 

sedimentary layer that sustains the meadow (table 5.3b.2). 

In Barley Canyon, a wet and mesic meadow complex was 

supported by a fine-grained, low-permeability unit overlying 

a sandy unit of high hydraulic conductivity (fig. 5.8). The 

stream at this site incised about 2 m wide and breached a 

confined aquifer that maintained a shallow water table. Once 

breached, the aquifer drained directly to the stream. The water table drop was so significant that wet and mesic plant 

communities were replaced by sagebrush and other drier 

meadow plants. Stream incision or creation of new channels 

in complex stratigraphic settings is likely to disrupt hydrologic conditions, locally resulting in loss of artesian flow 

or a perched water table (Shilling and others 2004), both of 

which would adversely impact the meadow.

Figure 5.7. Diagrams depict 

response of meadow to 

incision of a channel 

into sediment with 

(a) high permeability 

(high hydraulic 

conductivity) versus (b) 

low permeability. The 

drop in the water table 

will be more widespread 

in sediments of high 

hydraulic conductivity. 

At the Kingston 3 

meadow (c), incision 

of the channel caused 

a greater drop in the 

water table on the far 

side of the creek (see 

the sagebrush area 

in the photographs). 

The sediments at 

this site are part of 

an avulsion deposit 

(fig. 5.1). Analysis of 

sediment cores (white 

arrow) showed that two 

horizons in the upper 1 

m contained more than 

50 percent gravel.

Resistance of stratigraphic units is important to stream 

channel sensitivity and has direct implications to hydrologic 

sensitivity (table 5.3; fig. 5.9). In streams connected to the 

groundwater, depth of the channel determines depth of the 

water table. Where stream incision is inhibited by a resistant 

layer (such as a gravel-rich layer or a cohesive, fine-grained 

unit), the layer will prevent further decline in the water table. 

This controlling factor is demonstrated in many meadows 

where resistant gravel units that are deposited by side-valley 

alluvial fans at the downstream end of meadows have prevented or slowed incision (fig. 5.10).

Influence of Gully and Headcut Advancement

Incision results in varying degrees of loss of meadows 

that are dominated by wet and mesic plant communities regardless of whether incision occurs by individual particle 

entrainment or by knickpoint processes (Chapter 3). Loss of 

meadows can be particularly extensive within broad, lowgradient valleys such as in Indian Valley, where headcuts 

migrate upstream, enhanced by groundwater sapping, and 

produce a network of deeply entrenched gullies. However, 

headcut migration can result in water table levels that are 

located at or just below the floor of the broad, flat-bottomed 

trench. This occurs because the trench floor serves as the 

local base-level control for the water table. The net result is 

that the newly formed trench floor can support wet-meadow 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 81

vegetation (table 5.3c; fig. 5.11) (Jewett and others 2004). In 

areas where such conditions exist, a new trench-bottomed 

gully network will offset some of the loss of wet meadow 

vegetation and the decrease in overall habitat quality.

Influence of Source Waters

The hydrologic sensitivity of meadows is influenced by 

processes and properties that are external to meadows as 

well as those within meadows (table 5.3d). Understanding 

the recharge regions for meadow source waters is critical 

for effective management of ecological functions controlled 

by hydrology (Winter and others 2001; Loheide and others 

2009). The seasonal patterns of water table levels, or hydroperiods, in meadow complexes are strongly controlled 

by recharge characteristics. Source waters can be recharged 

from single or multiple source areas, can vary in scale from 

local to regional, can occur as diffuse recharge over broad 

areas or in concentrated areas as stream channel bed-focused 

recharge, and can occur over short to long periods of time 

(e.g., Winter and others 2001; Constantz and others 2007; 

Prudic and others 2007). The annual recharge of subsurface 

water levels is largely fed by snow, which usually melts 

over a short period of time, commonly in about one month 

(figs. 4.18 and 5.12). The response of water table levels in 

meadows will vary with location of the snowpack, pathway 

from snowmelt to meadow groundwater, and nature of the 

connections between surface water and groundwater. In 

meadows with complex hydrogeology, different parts of the 

same meadow complex may have different source waters 

and hydroperiods. These different sources or pathways of 

water can result in divergent groundwater-level trends within the same meadow—such as what occurs in the Kingston 

3 meadow (fig. 5.12).

Figure 5.8. Channel 

incision through a key 

hydrostratigraphic unit 

(a and b), such as a lowpermeability confining 

unit, can eliminate the 

hydrologic framework 

that supports shallow 

water tables. In Barley 

Canyon (c and d), a 

wet meadow complex 

was lost when channel 

incision progressed 

down through a finegrained unit into a 

high-permeability, sandy 

horizon.

Figure 5.9. Many meadows in the central Great Basin are 

perched and support perched streams that are underlain by 

low hydraulic conductivity, confining units. If the water from 

the perched stream supports the meadow, channel incision 

through the confining layer would likely result in the loss 

of wet plant communities, such as is shown in fig. 5.8. The 

photograph shows the lower portion of the Birch Creek 

meadow, which is supported by a perched water table.
82 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Figure 5.10. Stream incision that is not impeded by resistant stratigraphic units (a) will result in a larger drop in 

the groundwater table than where a resistant unit is encountered (b) that serves as a local base level control. 

A cobbly gravel sediment layer deposited by a side-valley alluvial fan at the Kinston 3 meadow serves to 

stabilize the stream (c) (see fig. 5.1).

Figure 5.11. Headcut migration of gully-trench systems (a and b) occurs at a continuum of scales in generally fine-grained 

sediments (c, d, and e) and is driven or enhanced by groundwater sapping. The groundwater table drops to the level 

of the new trench bottom and may intercept cross-valley shallow groundwater flow (fig. 5.6). With enlargement of the 

trench system, a wet-mesic meadow complex (e) may develop at the new lower elevation.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 83

A meadow with a small, source-water recharge area or 

short recharge period generally will be more sensitive to 

change than one with a larger recharge area and period. 

Conversely, meadows with predictable water tables, broad 

source areas, and long recharge cycles will be less sensitive to natural or anthropogenic change. To understand the 

hydrologic sensitivity of the system, the source of meadow 

groundwater needs to be identified and monitored. In lieu of 

or in addition to monitoring source waters, gathering continuous groundwater and stream water level data should be a 

management goal to at least understand the timing and patterns of recharge cycles.

Hydrologic Sensitivity Summary

The sensitivity of meadow complexes in the central Great 

Basin is controlled by numerous physical and biotic factors. 

The areas that are most naturally sensitive are most likely 

to change in response to anthropogenic activities. These 

meadow ecosystems require shallow water tables; therefore, 

understanding hydrogeologic controls on overall sensitivity is critical. Hydrologic sensitivity is controlled largely 

by meadow hydrogeology, especially by the interaction of 

groundwater and stream water, stratigraphy, geomorphic 

processes, and the area and timing of groundwater recharge. 

While all of the variations in these controls cannot be readily 

quantified, there are traits associated with different degrees 

of sensitivity. High hydrologic sensitivity is indicated by: 

(1) a meadow stream channel that has a continuous connection between groundwater and stream water, especially 

if the stream water recharges the groundwater; (2) complex 

stratigraphy, including highly permeable layers; (3) an active stream with high geomorphic sensitivity; and (4) source 

waters that recharge groundwater over limited space and 

over short periods of time. In contrast, low hydrologic sensitivity is indicated by meadows that: (1) are not intersected by 

stream channels that convey runoff; (2) are supported by regional groundwater discharge; (3) have simple stratigraphic 

sequences; and (4) have source waters of wide areal extent 

that recharge over extended periods of time.

The task of assessing sensitivity of meadow complexes 

can be difficult, but much can be learned by first identifying 

the processes and properties that control hydrologic and geomorphic sensitivity by assessing characteristics described in 

this chapter (tables 5.1 and 5.3). A preliminary grouping of 

meadows by sensitivity traits is an important first step in 

management of meadow systems, even though it must be 

followed by more detailed studies of target meadows. The 

discussions in Chapter 9 on meadow management and treatment options broaden this discussion by describing how 

sensitivity can be used as part of a strategy for resource scientists to monitor, manage, and restore meadow complexes.

References

Brunsden, D.; Thornes, J.B. 1979. Landscape sensitivity and 

change. Transactions, Institute of British Geographers. 4: 

463-484.

Downs, P.; Gregory, K. 1993. The sensitivity of river channels in 

the landscape system. In: Thomas, D.S.G.; Allison, R.J., eds. 

Landscape Sensitivity. Chichester, United Kingdom: John 

Wiley and Sons: 15-30.

Downs, P.; Gregory, K. 2004. River Channel Management; 

Towards Sustainable Catchment Hydrosystem. London, United 

Kingdom: Hodder Arnold. 395 p.

Chambers, J.C.; Miller, J.R., eds. 2004. Great Basin Riparian 

Ecosystems—Ecology, Management and Restoration. Covello, 

CA.: Island Press. 303 p.

Chambers, J.C.; Tausch, R.J.; Korfmacher, J.L.; Miller, J.R.; Jewett, 

D.G. 2004. Effects of geomorphic processes and hydrologic 

regimes on riparian vegetation. In: Chambers, J.C.; Miller, J.R., 

eds. Great Basin Riparian Ecosystems—Ecology, Management 

and Restoration. Covelo, CA: Island Press: 196-231.

Constantz, J.; Adams, K.S.; Stonestrom, D.A. 2007. Overview of 

ground-water recharge study sites—Chapter C. In: Stonestrom, 

D.A.; Constantz, J.; Ferré, T.P.A.; Leake, S.A. Ground-water 

recharge in the arid and semiarid southwestern United States. 

U.S. Geological Survey Professional Paper. 1703: 61-82.

Figure 5.12. Groundwater elevations at two well sites—101S 

and 54S—in the Kingston 3 meadow show synchronous 

responses early in the annual, snow-melt driven rise of 

water levels, but they have divergent responses after May 

20th. The lower plot shows snow water equivalent data 

for the nearby, high-elevation (2650 m) Big Creek SNOTEL 

site. These divergent responses are explained by stagedependent differences in connectivity between the source 

waters and the meadow.

94.6

94.7 101S

94.2

94.3

94.4

94.5

groundwater elev. (m) 

96.6

96.7

96.8

96.9

97.0

54S

60

80

100

Big Creek Snotel

ground

96.5

water elev. (m)

4/1/2005

0

20

40

Snow water Equivalent (cm)

4/22/20054/29/2005

5/6/2005

5/13/2005

5/20/20055/27/2005

6/3/2005

6/10/2005
84 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Freeze, R.A.; Cherry, J.A. 1979. Groundwater. Englewood Cliffs, 

NJ: Prentice-Hall Inc. 604 p.

Germanoski, D.; Miller, J.R. 2004. Basin sensitivity to channel 

incision in reponse to natural and anthropogenic disturbance. 

In: Chambers, J.C.; Miller, J.R., eds. Great Basin Riparian 

Ecosystems—Ecology, Management and Restoration. Covello, 

CA: Island Press: 88-123.

Griffiths, R.E.; Anderson, D.E.; Springer, A.E. 2008. Morphology 

and hydrology of small spring-dominated channels. 

Geomorphology. 102: 511-521.

Hammersmark, C.T.; Rains, M.C.; Mount, J.F. 2008. Quantifying the 

hydrologic effects of stream restoration in a montane meadow, 

northern California, USA. River Research Applications. 24: 

735-753.

Hayashi, M.; Rosenberry, D. 2002. Effects of ground water 

exchange on the hydrology and ecology of surface water. 

Ground Water. 40(3): 309-316.

Jewett, D.G.; Lord, M.L.; Miller, J.R.; Chambers, J.C. 2004. 

Geomorphic and hydrologic controls on surface and subsurface 

flow regimes in riparian meadow ecosystems. In: Chambers, 

J.C.; Miller, J.R., eds. Great Basin Riparian Ecosystems—

Ecology, Management and Restoration. Covello, CA: Island 

Press: 124-161.

Jones, L.S.; Schumm, S.A. 1999. Causes of avulsion: an overview. 

Special Publications in Association of Sedimentology. 28: 

171-178.

Lerner, D.N. 2003. Surface water-groundwater interactions in the 

context of groundwater resources. In: Xu, Y.; Beekman, H.E., 

eds. Groundwater recharge estimation in Southern Africa. IHP 

Series No. 64. UNESCO, Paris: 91-107, ISBN 92-9220-000-3.

Loheide, S.P.; Deitchman, R.S.; Cooper, D.J.; Wolf, E.C.; 

Hammersmark, C.T.; Lundquist, J.D. 2009. A framework for 

understanding the hydroecology of impacted wet meadows 

in the Sierra Nevada and Cascade Ranges, California, USA. 

Hydrogeology Journal. 17: 229-246.

Loheide, S.P., II; Gorelick, S.M. 2007. Riparian hydroecology: a 

coupled model of the observed interactions between groundwater 

flow and meadow vegetation patterning. Water Resources 

Research 43, W07414, doi: 10.1029/2006WR005233.

Lord, M.; Jewett, D.; Miller, J.; Germanoski, D.; Chambers, J.; 

Sturtevant, K.; Baker, G. 2007. Hydrology of central Great 

Basin meadow ecosystems—effects of stream incision: Abstract 

Volume. Sixtieth annual meeting of the Society for Range 

Management, Reno, NV.

Miller, J.R.; House, K.; Germanoski, D.; Tausch, R.J.; Chambers, 

J.C. 2004. Fluvial geomorphic responses to Holocene climate 

change. In: Chambers, J.C.; Miller, J.R., eds. Great Basin 

Riparian Ecosystems—Ecology, Management and Restoration. 

Covelo, CA: Island Press: 49-87.

Pilkey, O.H.; Pilkey-Jarvis, L. 2007. Useless Arithmetric: Why 

Environmental Scientists Can’t Predict the Future. New York, 

NY: Columbia University Press. 230 p.

Prudic, D.E.; Niswonger, R.G.; Harrill, J.R.; Woods, J.L. 2007. 

Streambed infiltration and ground-water flow from the Trout 

Creek Drainage, an intermittent tributary to the Humboldt 

River, north-central Nevada—Chapter K. In: Stonestrom, D.A.; 

Constantz, J.; Ferré, T.P.A.; Leake, S.A. Ground-water recharge 

in the arid and semiarid southwestern United States. U.S. 

Geological Survey Professional Paper. 1703: 313-351.

Reid, L.M.; Dunne, T. 1996. Rapid Evaluation of Sediment 

Budgets. Reiskirchen: Germany: Catena Verlag. 164 p.

Schilling, K.E.; Zhang, Y.K.; Drobney, P. 2004. Water table 

fluctuations near an incised stream, Walnut Creek, Iowa. Journal 

of Hydrology. 286: 236-248.

Schilling, K.E.; Zhongwei, L.; Zhang, Y. 2005. Groundwatersurface water interaction in the riparian zone of an incised 

channel, Walnut Creek, Iowa. Journal of Hydrology. 327: 

140-150.

Shields, A. 1936. Anwendung der Ahnlichkeitsmechanik und 

Turbulenzforschung auf die Geschiebebewegung. Report 26, 

Berlin: Mitteil. Preuss. Versuchsant. Wasserbau und Schiffsbau. 

24 p.

Sophocleous, Marios. 2002. Interactions between groundwater and 

surface water: the state of the science. Hydrogeology Journal. 

10: 52-67.

Stromberg, J.C.; Tiller, R.; Richter, B. 1996. Effects of groundwater 

decline on riparian vegetation of semiarid regions: the San 

Pedro, Arizona. Ecological Applications. 6(1): 113-131.

Vidon, P.G.; Hill, A.R. 2004. Landscape controls on the hydrology 

of stream riparian zones. Journal of Hydrology. 292: 210-228.

Vidon, P.G.; Hill, A.R. 2006. Landscape-based approach to estimate 

riparian hydrological and nitrate removal functions. Journal of 

the American Water Resources Association. 42(4):1099-1112.

Webb, R.H.; Leake, S.A. 2006. Ground-water surface-water 

interactions and long-term change in riverine vegetation in 

the southwestern United States. Journal of Hydrology. 320: 

302-323.

Williams, G.P. 1983. Paleohydrological metehods and some 

examples from Swidish fluvial environments. Geografiska 

Annaler. 65A: 227-244.

Winter, T.C.; Rosenberry, D.O.; Buso, D.C.; Merk, D.A. 2001. 

Water source to four U.S. wetlands: implications for wetland 

management. Wetlands 21(4): 462-473.

Woessner, W.W. 2000. Stream and fluvial plain ground water 

interactions: rescaling hydrogeologic thought. Ground Water. 

38(3): 423-429.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 85

Introduction

Riparian areas make up less than 1 percent of the total area of the Great Basin, yet they provide many critical 

ecosystem services, and they support a disproportionately 

large percentage of the regional biodiversity (Hubbard 1977; 

Saab and Groves 1992). Jenson and Platts (1990) estimate 

that over 50 percent of the riparian areas in the Great Basin 

are in poor ecological condition due to various forms of disturbance and climate change (Chambers and Miller 2004). 

Ongoing stream incision in the region and progressive 

degradation of riparian meadow complexes make meadow systems a management priority (Chambers and Miller 

2004). Understanding the connections between benthic 

macroinvertebrate (BMI) communities and meadow-stream 

environmental characteristics provides managers with important information about the effects of this degradation.

Biological surveys of BMI communities have been used 

along with water chemistry analyses to indicate environmental conditions in other lotic ecosystems (Yoder and 

Rankin 1998; Karr and Chu 1999). Benthic invertebrates 

are relatively long-lived, diverse, and ubiquitous (Linke and 

others 1999). Due to these factors and because their response 

to disturbance is broad, they are good indicators of system 

changes.

Previous ecological research in Great Basin streams of 

Nevada has focused on links between riparian condition 

and aquatic invertebrate community structure (Kennedy and 

others 2000); invertebrate community responses to spring 

disturbance (Sada and others 2005); and assemblage clustering driven by natural environmental gradients (Myers 

and Resh 2002). Our study builds, in part, upon the work of 

Kennedy and others (2000), who found that community composition was strongly related to a number of environmental 

parameters such as total dissolved residue, fish diversity, 

and percent silt. Since relationships between landscape and 

benthic composition have been demonstrated, we sought to 

examine whether such relationships could be shown using 

common benthic measurements.

While there have been studies of the nutrient dynamics of 

central Great Basin streams, little research has documented 

the temporal and spatial patterns of environmental characteristics and the resulting implications for aquatic invertebrate 

communities in meadow reaches. Amacher and others (2004) 

demonstrated that catchment lithology is an important driver 

of stream water chemistry in Kingston Creek and other upland Toiyabe streams. Mast and Clow (2000) showed that 

early season snowmelt can dilute aqueous nutrients derived 

from catchment lithology.

In 2005, we initiated a study to determine if multimetric 

bioassessment methods that are commonly used by management agencies in the United States are sensitive to riparian 

meadow influences on benthic communities at Kingston 

Creek. Comparing multimetric and multivariate methods, 

we investigated whether a meadow environment affects 

community structure by sampling invertebrates and environmental characteristics at finer spatial and temporal scales 

than in previous work.

Methods

Data Collection

We collected invertebrates and environmental data at 12 

sites upstream, within, and downstream of Kingston 3 meadow (figs. 1.7 and 6.1). There is a 50-m vertical drop across 

the 2000-m sampled area. The discharges of multiple springs 

within the meadow merge into two main tributaries that join 

the main creek at the bottom of the meadow reach. Sampling 

was conducted in 2005 in late spring (May), early summer 

(June), mid summer (July), late summer (August), and early 

fall (October).

All environmental parameters and invertebrate metrics that were measured are listed in table 6.1. Sites were 

sampled on approximately two-week intervals for environmental parameters. Depth, current velocity, and dominant 

substrate size were measured at five equidistant points along 

a stream cross-section transect for each site (Sanders 1998). 

Velocity was measured with a Marsh-McBirney Flo-mate 

2000 current meter, and discharge was calculated using the 

cross-sectional area method (Sanders 1998). Dissolved oxygen, temperature, and specific conductivity were measured 

with a handheld probe (YSI-85). Dominant substrate size 

was categorized as fine sediment, sand, gravel, cobble, or 

boulder. Seasonal cover of vegetation over the stream was 

measured at the center of each transect using a densiometer 

(Barbour and others 1999). A water sample was obtained 

at each site using the depth-integrated equal-transit-rateequal-width-increment method (Amacher and others 2004). 

Water samples were kept in refrigerated, dark conditions until processing. A mixed subsample was filtered using GF/F 

filters (0.7 μm) and measured for dissolved nutrients (nitrate, ammonium, soluble reactive phosphorous, and total 

dissolved phosphorous) and total phosphorus at the Aquatic 

Ecosystems Analysis Laboratory (AEAL) at the University 

of Nevada, Reno, and at the High Sierra Water Lab using 

standard methods (Hunter and others 1993).

Chapter 6: Meadow-Stream Processes and 

Aquatic Invertebrate Community Structure

Chris A. Jannusch, Sudeep Chandra, Tom Dudley, 

Jeanne C. Chambers, and Wendy Trowbridge
86 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Figure 6.1. Kingston 3 

meadow and sampling 

locations. This 

meadow lies at an 

approximate elevation 

of 2325 m. These sites 

encompassed close to 

50 m in vertical gain 

and spanned nearly 

2000 m of the creek. 

Sites 1 through 4 

(below meadow) and 

5 through 9 (meadow) 

had sufficient stream 

depths for sampling 

throughout the 

sampling season. Sites 

10 through 12 (above 

meadow) were dropped 

from analysis.

Table 6.1. Environmental variables measured and bioassessment metrics calculated for Kingston 

Creek. EPT = Ephemeroptera, Plecotera, and Trichoptera.

Environmental parameters Invertebrate metrics

Stream Discharge Abundance

Substrate Size Total Taxa

Percent Vegetative Cover EPT Abundance

Specific Conductivity Diptera Richness

Dissolved Oxygen (DO) EPT Richness

Nitrate (NO3) Percent Tolerant Taxa

Ammonium (NH4) Percent Intolerant Taxa

Soluble Reactive Phosphorous (SRP) Percent Dominance

Total Dissolved Phosphorous (TDP) Percent Non-insect Taxa

Total Phosphorus (TP) Percent EPT Richness

Percent EPT Abundance

Ephemeroptera Richness

Plecoptera Richness

Trichoptera Richness

Percent Chironomidae Richness

Hilsenhoff Biotic Index (modified)

Shannon Diversity Index

Percent Shredders

Percent Scrapers

Percent Filterer-Collectors

Percent Gatherer-Collectors

Percent Predators
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 87

BMI sampling and habitat characterization took place 

approximately every four weeks. Two invertebrate samples 

were taken at each site. U.S. Environmental Protection 

Agency (USEPA) protocols (Barbour and others 1999), 

UC-Sierra Nevada Aquatic Research Lab protocols (Herbst 

and Silldorff 2006), and California Department of Fish and 

Game protocols (CA DFG 2003) were modified for this 

study. Two BMI samples were obtained from each site using a Hess-type surber sampler (0.105 m2

, 247 μm mesh 

size). In order to obtain a more accurate representation of 

community structure within each site, samples were taken 

from the different microhabitat types that were present 

(Kerans and others 1992)—one from the thalweg and one 

from the stream edge. Data from thalweg and edge samples 

were then combined for each site because effects of environmental parameters on invertebrates are detectable across 

microhabitats (Parsons and Norris 1996; Rehn and others 

2007). Samples were preserved in the field using 70 percent ethanol. Invertebrates were picked from substrate at 

the AEAL under dissecting microscopes. Invertebrates, 

excluding early instars, were enumerated and identified to 

genus—except for oligochaetes and water mites, which were 

identified to order, and chironomidae, which were identified to 

sub-family—using Merritt and Cummins (1996), Wiggins 

(1996), Stewart and Stark (2002), Thorp and Covich 

(1991), and Post (2005). The California Department of Fish 

and Game’s Aquatic Biology Laboratory at Chico State 

University verified taxa.

Data Analysis

Cross-sectional stream discharge varied from 0.01 to 

0.26 m3/sec and stream depths ranged from 2 to 34 cm. Over 

the course of the study, the farthest upstream sites dried up. At 

sites where stream depths dropped below our ability to sample (5 cm), the sites were removed from our analysis. This 

threshold eliminated the three sites above the meadow and 

gradually reduced our meadow sites from six to three over 

the course of the field season. In addition, the earliest sample 

points—late spring and early summer—were removed from 

analysis because invertebrate totals (<500 individuals) were 

insufficient to meet standard USDA Forest Service/USEPA 

and California bioassessment criteria (Barbour and others 

1999; Herbst and Silldorff 2006). Therefore, we analyzed 

the remaining two reaches—meadow and below meadow—

in mid summer, late summer, and early fall.

For each of the three time periods, we compared invertebrate communities between the two reaches with 

multi-response permutation procedures (MRPP). Groups 

were defined by reach (meadow or below meadow) and we 

examined species composition at each site. The Sørensen 

distance method (also known as Bray-Curtis) was used in 

this procedure since it performs well with ecological data 

(McCune and Grace 2002). MRPP was used for a number 

of reasons. It is a nonparametric method that was developed 

for testing group differences (McCune and Grace 2002). It 

is closely related to non-parametric multivariate analysis of 

variance (MANOVA) used by Sada and others (2005) for 

assessing aquatic invertebrate community similarity across 

disturbance gradients in the Great Basin. Zimmerman and 

others (1985) applied a variant of MRPP to examine vegetation community differences in the Great Basin.

Stream reaches that MRPP demonstrated to be biologically distinct from one another (p<0.05) at the community 

scale within a given season were analyzed further for reachspecific relationships among invertebrate metrics, invertebrate taxa, and environmental variables. Abundances 

of individual taxa were compared between reaches using 

analysis of variance (ANOVA) to illustrate taxon-driven 

community differences. Dominant taxa were also examined 

for their possible role in contributing to the differences between reaches and over time.

For the multimetric analysis, we calculated 22 invertebrate metrics based on Herbst and Silldorff’s (2006) benthic 

index of biotic integrity (B-IBI) for the eastern Sierra and 

western Great Basin (table 6.1). Hilsenhoff biotic index 

values for individual taxa that indicate tolerance/intolerance to organic pollution were taken from EPA’s northwest 

assessment (Barbour and others 1999). Metric values were 

aggregated and scaled to 0 to 10 (Barbour and others 1999). 

B-IBI values were created from composites of scaled biological metrics (Herbst and Silldorff 2006) for each reach by 

season (table 6.2). We evaluated the B-IBI values for each 

reach over time and compared reaches. Like MRPP, this approach is designed to illustrate spatio-temporal changes in 

community composition (Barbour and others 1999).

Environmental variables (table 6.1) were sampled approximately every two weeks—twice as frequently as 

invertebrate—during mid summer and late summer. During 

those two seasons, environmental data were averaged from 

two dates within each season. One sample was taken during early fall. We performed individual ANOVAs for each 

environmental variable to test whether they differed across 

reaches. Environmental variables were assessed for normality (skew<2 standard deviations) in PC-ORD. Non-normal 

distributions were monotonically log transformed. To identify relationships over time, Pearson’s coefficients were 

calculated using invertebrate metrics and environmental 

data for each season (Myers and Resh 2002). We defined 

highly correlated relationships as those with r-values greater than |0.90| (Myers and Resh 2002). Linear relationships 

between environmental variables and invertebrate metrics 

would indicate the potential of fine-scale biotic and abiotic 

interactions.

Results

Seventy-two taxa (table 6.3) and 40,494 invertebrates 

were identified. The multivariate (MRPP) and multimetric (B-IBI) methods we used to compare the meadow and 

below-meadow communities provided differing results. 

MRPP indicated that significant community-level differences existed between reaches during mid summer (p = 0.04, 

n = 9) and late summer (p = 0.02, n = 8). No measurable 

community difference was detected between reaches in early 

fall (p = 0.53, n = 6). B-IBI scores, however, were identical 
88 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

during mid summer, late summer, and early fall, indicating 

no substantial metric level difference between the reaches 

(table 6.2). While the index scores were identical across 

reaches within season, the scores gradually increased from 

three to five from mid summer to early fall (table 6.2). To 

investigate patterns in the taxon-driven distinctions between 

reaches, we used ANOVA to examine dynamics in individual taxa beginning with the dominant taxa.

The midge subfamily Orthocladiinae was the dominant taxon for all sites, regardless of reach, during mid 

summer (range 43 to 85%). The mayfly Baetis dominated 

sample composition for all sites during late summer (range 

45 to 86%). In mid summer, the mayfly Drunella and 

Orthocladiinae were found in higher numbers in the meadow reach compared to below meadow, though at marginally 

significant values (p = 0.056 and p = 0.063, respectively). 

During late summer, the mayfly genus Baetis occurred in 

significantly higher numbers at the meadow reach compared 

to below meadow (p = 0.042). Environmental variable comparisons provide additional context for variations found in 

the invertebrate community.

By fall, there is no flow above the meadow, and the flow 

within and below the meadow is supported by groundwater 

inputs. Consequently, discharge was greater at the belowmeadow reach during both mid summer and late summer 

(table 6.4). In mid summer, substrate size was greater at the 

below-meadow reach of the stream (table 6.4). Specific conductivity values ranged from 353 to 467 μS/cm. Dissolved 

oxygen levels varied between 4.77 and 7.36 mg/l. Aquatic 

nutrient ranges are illustrated in fig. 6.2. Specific conductivity and total phosphorous were greater in the meadow reach 

than below the meadow during late summer (table 6.4; fig. 

6.3). This pattern suggests that the two springs within the 

meadow have distinct influences on water chemistry, most 

noticeably on specific conductivity and total phosphorous.

The two spring tributaries had distinct impacts on water 

quality that varied by season (fig. 6.3). Total phosphorous 

concentrations in the stream increased downstream of the 

upper spring tributary during late summer (table 6.4; fig. 

6.3). Immediately downstream from the lower spring, specific conductivity dropped in mid summer, stabilized in late 

summer, and increased during early fall (fig. 6.3). Specific 

conductivity levels typically increased from mid summer to 

late summer to early fall as the influence of groundwater 

increased.

Irrespective of reach, a number of relationships between 

invertebrate metrics and environmental parameters for mid 

summer, late summer, and early fall were notable. Correlation 

patterns of those relationships changed across seasons. The 

number of highly correlated relationships between environmental parameters and invertebrate metrics (with r>|0.90|) 

increased from zero in mid summer to five in late summer to 

eight in early fall (tables 6.5 through 6.7). During late summer, discharge, dissolved oxygen (DO), and overstory cover 

were all correlated with three metrics (table 6.6). Discharge 

and DO both correlated with the percent of intolerant taxa 

and percent of shredder taxa. Overstory, however, was correlated with the percent of Ephemeroptera, Plecotera, and 

Table 6.2. Taxa list for Kingston Creek upper meadow-stream. 

Taxa with an asterisk are predators found in early fall. EPA 

tolerance values assessed for Idaho were used.

Order/Suborder Family Genera

Trombidformes/Hydracarina

Amphipoda Crangonyctidae Crangonyx

 Gammaridae Gammarus

 Pontoporeiidae Monoporeia

 Gastropoda Gastropoda

Nematoda

Nematomorpha

Bivalvia

Oligochaeta

Ostracoda

Ephemeroptera Baetidae Baetis

 Acerpenna

 Ephemerellidae Drunella

 Heptageniidae Cinygmula

 Epeorus

 Sipholonuridae Parameletus

Plecoptera Chloroperlidae Haploperla

 Nemouridae Malenka

 Zapada

Trichoptera Brachycentridae Micrasema

 Brachycentrus

 Glossosomatidae Glossosoma

 Hydropsychidae Parapsyche*

 Arctopsyche

Leptonema

Hydropsyche

 Hydroptilidae Hydroptila

 Orthotrichia

Metrichia

 Lepidostomatidae Lepidostoma

 Psycopglypha

 Limnephilidae Limnephilus

 Hesperophylax*

Clostocea

 Odontoceridae Namamyia

 Philopotamidae Dolophilodes

 Polycentropodidae Polycentropus*

 Rhyacophilidae Rhyacophila*

Diptera Ceratopogonidae Leptoconops

 Culicoides

Probezzia*

 Chironomidae Orthocladinae

 Diamesinae

Chironomini

Tanypodinae

Tanytarsini

 Dixidae Dixa

 Psychodidae Pericoma/

 Telmatoscopus

 Simuliidae Simulium

 Prosimulium

 Tipulidae Antocha

 Dicranota*

Pedicia

Coleoptera Dytiscidae Dytiscus

 Elmidae Stenelmis

 Atractelmis/

Cleptelmis

Zaitzevia

Optioservus

Gonielmis

Heterlimnius

Narpus

Ordobrevia

Ampumixis

 Hydrophilidae Helobata

 Laccobius

Lepidoptera Pyralidae Pyralidae
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 89

Trichoptera (EPT) richness. Four environmental variables 

were found to correlate with six metrics in the early fall 

(table 6.7). Three environmental variables (discharge, TP, 

and NH4) were highly correlated with multiple invertebrate 

metrics. These results reveal that correlations between environmental variables and community metrics increase from 

mid summer to early fall. Only in early fall did we see aquatic 

nutrients correlate with invertebrate metrics. Total phosphorous, ammonia, and nitrate correlated with percent EPT, 

non-insect abundance, plecoptera richness, percent shredder 

taxa, and tolerant/intolerant taxa. Pearson’s coefficient calculations examined data on a site-by-site basis, indicating 

Table 6.3. Scaled metric values and index scores for meadow and below-meadow reaches during three seasons.

Mid summer Late summer Early fall

Below-meadow Meadow Below-meadow Meadow Below-meadow Meadow

Density 0 3 1 4 3 3

Total Taxa 5 6 4 5 8 7

EPT Richness 2 3 2 3 8 7

EPT Abundance 0 1 1 5 3 2

Diptera Richness 6 8 5 6 6 6

Percent Dominance 8 7 8 8 6 6

Percent Non-insect 1 1 1 1 1 6

Shannon Index 6 6 5 5 8 7

Percent EPT Richness 3 4 5 4 9 8

Percent EPT Abundance 1 1 8 8 7 7

E. Richness 5 7 4 4 6 6

P. Richness 1 0 4 6 5 8

T. Richness 1 2 1 1 8 5

Percent Chironomid Richness 5 4 6 6 3 3

Percent Intolerant Taxa 0 0 1 2 5 5

Percent Tolerant Taxa 1 1 0 0 1 5

Percent Shredders 0 0 1 2 2 5

Percent Scrapers 3 0 0 0 1 1

Percent Filterer-Collectors 1 4 2 2 6 1

Percent Gatherer-Collectors 9 8 9 8 6 8

Percent Predators 2 2 2 1 7 2

Hilsenhoff Biotic Index 7 8 8 8 7 8

Index scores 3 3 4 4 5 5

n = 4 n = 5 n = 4 n = 4 n = 4 n = 2

Table 6.4. Results from ANOVA among variables between meadow and belowmeadow reaches for each season. Single asterisks indicate transformed 

distributions. Numbers in bold are significant at p<0.05. See table 6.1 for 

abbreviated variables.

Variables Mid summer Late summer Early fall

Discharge (m3/s) <0.01 <0.01 0.46

DO (mg/L) 0.61 0.71* 0.22

Specific Conductivity (μS/cm) 0.17 <0.01 0.55

TDP (μg/L) 0.06 0.07 0.08

SRP (μg/L) 0.07 0.1 0.07

NH4 (μg/L) 0.36* 0.75 0.54

NO3 (μg/L) 0.96 0.1 0.1

TP (μg/L) 0.37 <0.01 0.08

Overstory Cover (percent) 0.89 0.87 0.37

Substrate Size 0.02 1 0.2

Number of sites n = 9 n = 8 n = 6

the influence of the environmental variables on community 

structure, irrespective of possible meadow effects.

Discussion

The degradation of central Great Basin meadow ecosystems presents an important management challenge. These 

meadows are highly productive habitat islands (Sada and 

others 2005) but they are prone to channel incision and 

desiccation. Understanding the relationship between changing environmental characteristics and BMI communities 
90 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

provides managers with important information about the 

impact of meadow degradation on aquatic ecosystems. In 

Kingston Creek, we found strong relationships between environmental characteristics and BMI communities. There 

were, however, important seasonal differences and differences in the results of the two different analytical methods 

we used (MRPP and multimetric bioassesments).

The seasonal variation we observed was largely driven 

by surface water run-off and the relative contribution of 

groundwater springs. Throughout the season, the water 

chemistry changed as surface water runoff decreased and 

the relative contribution of groundwater increased. The two 

spring tributaries had distinct impacts on water quality that 

varied by season (fig. 6.3). Total phosphorous concentrations in the stream increased downstream of the upper spring 

tributary during late summer (table 6.4; fig. 6.3). In addition, 

Amacher and others (2004) suggest that plant community 

type may subtly influence water quality on a seasonal basis 

in these systems. The MRPP analysis illustrated that meadow and below-meadow reaches are biologically distinct 

from each other during mid and late summer but their populations homogenize during the early fall when surface flows 

are lowest and the number of correlations between metrics 

and environmental parameters is greatest. Hannah and others (2007) also found that as spatio-temporal heterogeneity 

of water sources for mountain streams decreased, invertebrate diversity decreased. Benthic communities in glacial 

streams also show seasonal variation that is related to the 

dominant water source (Burgherr and others 2002).

There are several analytical issues that also may have 

contributed to the fall community homogeneity detected 

by the MRPP and multimetric method. Two alternative effects may explain this apparent homogeneity. First, because 

some sites could not be measured in fall, the smaller sample 

size led to decreased statistical power to detect community 

differences. Second, sites that were not measured in the fall 

may have been driving community variability within the 

meadow. Though both MRPP and the multimetric method 

describe population homogeneity in the fall, these other factors may be affecting that observation.

Comparing the results of the two analyses demonstrates 

that these methods analyze different components of community data. Since multimetric bioassesment is based on 

indices (i.e., diversity, functional feeding groups, and EPT 

richness), numeric fluctuations in individual taxa can be 

masked within the metrics. Conversely, because the MRPP 

tests for community differences at the taxon scale, it does 

not detect evenly occurring changes in abundance like multimetric bioassessments. An inspection of the dominant 

taxa in Kingston Creek shows why the two methods differ. 

While there were taxonomic differences between the two 

reaches with more Orthocladiinae in the meadow in mid 

summer and more Baetidae in the meadow in late summer, 

raw percentage values of taxonomic dominance remained 

unchanged. Functional feeding group and tolerance/intolerance metrics also were unable to recognize the community 

change since Orthocladiinae and Baetidae have identical 

values (filterer-collectors and Hilsenhoff biotic index values 

of five). However, MRPP does detect differences in composition between the reaches during this time period.

Kennedy and others (2000) examined 19 Great Basin 

streams in early summer and found that substrate size was 

one of several in-stream characteristics related to invertebrate indices. The strength of the observed relationships 

may have been, in part, a function of the season in which 

the data were collected. Studies of both mountain and desert 

streams have recognized that spatio-temporal variation of 

invertebrate communities across seasons are driven by environmental variables (Boulton and others 1992; Robinson 

and others 2001). Beche and Resh (2007) also documented 

Figure 6.2. Aquatic 

nutrient ranges for 

nine sites at Kingston 

Creek from mid 

summer through early 

fall. The 25th and 75th 

percentiles are shown 

as a box around the 

50th percentile. The 

error bars represent 

the highest and lowest 

values within the 

upper and lower limits 

where the upper limit 

is Q3 + 1.5 (Q3 - Q1) 

and the lower limit is 

Q1 - 1.5 (Q3 - Q1).
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 91

Figure 6.3. Panel illustrating the metrics and environmental variables that were significant in distinguishing meadow 

and below meadow reaches during late summer. Stream flow is from left to right. Solid trend lines indicate p<0.05. 

Gray shading represents meadow extent. Vertical lines represent noted springs.
92 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Table 6.5. Pearson’s Coefficients for metrics and environmental variables for mid summer. 

Values representing highly correlated relationships (r>|0.90|) between metrics and 

environmental variables are boxed and bold. Highly correlated relationships increase in 

number from mid summer to early fall. See table 6.1 for abbreviations of variables.

 Specific

Discharge DO conductivity NH4 NO3

Abundance -0.81 0.18 0.01 -0.33 0.85

Total Taxa -0.56 0.56 -0.28 0.05 0.68

EPT Richness -0.43 0.40 -0.09 -0.23 0.58

EPT Abundance -0.83 0.23 -0.02 -0.29 0.81

Shannon Diversity -0.10 0.43 -0.08 -0.03 -0.17

Percent Dominant Taxa 0.66 -0.37 -0.03 0.26 -0.17

Percent Non-insect Taxa 0.43 0.44 -0.22 0.11 -0.08

Percent EPT Richness -0.26 0.53 -0.06 -0.13 0.31

Percent EPT Abundance -0.01 0.80 -0.52 0.43 -0.04

Ephemeroptera Richness -0.34 0.62 -0.21 -0.05 0.37

Trichoptera Richness -0.49 0.21 -0.04 -0.37 0.68

Percent Chironomid Richness 0.42 -0.69 0.30 -0.03 -0.59

Percent Intolerant Taxa 0.30 0.29 -0.07 -0.03 -0.39

Percent Tolerant Taxa 0.37 0.17 -0.16 -0.10 -0.27

Percent Shredders 0.44 0.17 -0.11 0.03 -0.34

Percent Scrapers 0.40 0.14 -0.13 -0.05 -0.36

Percent Filterer-Collectors -0.84 0.06 0.05 -0.30 0.52

Percent Gatherer-Collectors 0.71 -0.14 0.02 0.30 -0.40

Table 6.6. Pearson’s coefficients for metrics and environmental variables for late summer. Values 

representing highly correlated relationships (r>|0.90|) between metrics and environmental variables are 

boxed and bold. Highly correlated relationships increase in number from mid summer to early fall. See 

table 6.1 for abbreviated variables.

Discharge DO Overstory TDP SRP TP

Abundance -0.79 -0.73 0.48 0.51 0.68 0.58

Total Taxa -0.61 -0.63 0.34 0.43 0.64 0.42

EPT Richness -0.41 -0.53 0.88 -0.04 0.12 -0.11

EPT Abundance -0.87 -0.82 0.41 0.57 0.73 0.66

Percent Dominant Taxa 0.39 0.49 -0.71 -0.32 -0.44 -0.18

Percent Non-insect Taxa 0.15 0.11 -0.64 0.39 0.48 0.26

Percent EPT Richness -0.08 -0.27 0.91 -0.35 -0.28 -0.50

Percent EPT Abundance 0.22 0.32 -0.66 -0.25 -0.35 -0.05

Ephemeroptera Richness -0.13 -0.39 0.77 -0.41 -0.25 -0.46

Plecoptera Richness -0.69 -0.87 0.57 0.37 0.60 0.43

Trichoptera Richness -0.30 -0.28 0.85 -0.05 0.03 -0.17

Percent Intolerant Taxa -0.91 -0.91 0.45 0.45 0.57 0.63

Percent Tolerant Taxa 0.48 0.48 -0.62 0.15 0.18 0.01

Percent Shredders -0.92 -0.91 0.40 0.49 0.61 0.68

Percent Scrapers -0.87 -0.66 0.29 0.65 0.54 0.77

Percent Filterer-Collectors -0.48 -0.49 0.83 0.16 0.22 0.09

Percent Gatherer-Collectors 0.57 0.59 -0.81 -0.22 -0.31 -0.21
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 93

inter- and intra-region temporal variability of invertebrate 

assemblages in California streams. Maloney and Feminella 

(2006) found high seasonal variability in individual metrics 

when examining stream disturbance gradients and concluded that such metrics would not be appropriate to use alone. 

We found that in Kingston Creek, the relationship between 

environmental variables and invertebrate communities 

changed throughout the seasons and the reach differences 

were largest in mid summer when there is a mix of surface 

and groundwater.

Management Summary

These findings have important implications for managing 

aquatic resources in Kingston Creek and other Great Basin 

stream systems. The fact that the stream systems are incision 

prone makes establishing reference sites a formidable task. 

As a result, effective assessment and monitoring of these 

stream and meadow ecosystems require the following:

1. Locate monitoring sites for aquatic invertebrates based on 

an understanding of the past and present disturbance regime and of surface and groundwater dynamics. Because 

many Great Basin streams are incising, sites should be 

located in areas with minimal risk of incision (Chapters 

3, 5, and 7). Also, to determine the relative influence of 

groundwater inputs on aquatic invertebrates, sites ideally 

would be paired and would include locations with and 

without groundwater inputs (Chapter 4). Finally, sites 

should be located in areas that are known to have perennial flow.

Table 6.7. Pearson’s coefficients for metrics and environmental variables for early fall. Values representing highly 

correlated relationships (r>|0.90|) between metrics and environmental variables are boxed and bold. Highly 

correlated relationships increase in number from mid summer to early fall. See table 6.1 for abbreviated 

variables.

 

Discharge Overstory DO TDP TP NH4 NO3

Abundance 0.42 0.82 -0.32 -0.53 -0.22 0.72 0.64

Total Taxa 0.06 0.86 -0.74 -0.62 0.04 0.32 0.52

EPT Richness -0.16 0.76 -0.88 -0.54 0.10 0.03 0.40

EPT Abundance 0.06 0.93 -0.63 -0.76 -0.03 0.31 0.52

Diptera Richness 0.29 0.78 -0.37 -0.71 -0.19 0.41 0.56

Percent Dominant Taxa -0.15 -0.80 0.51 0.46 -0.06 -0.57 -0.47

Percent Non-insect Taxa 0.49 -0.26 0.69 0.47 0.00 0.81 -0.02

Percent EPT Abundance -0.69 -0.43 -0.07 0.08 0.37 -0.96 -0.59

Plecoptera Richness -0.95 -0.22 -0.04 0.37 0.98 -0.40 -0.84

Trichoptera Richness 0.07 0.84 -0.89 -0.68 -0.13 0.11 0.61

Percent Intolerant Taxa -0.94 0.04 -0.48 -0.07 0.74 -0.72 -0.55

Percent Tolerant Taxa 0.51 -0.23 0.70 0.47 -0.03 0.84 0.00

Percent Shredders -0.95 -0.10 -0.20 0.21 0.95 -0.47 -0.74

Percent Filterer-Collectors 0.28 0.83 -0.70 -0.64 -0.46 0.24 0.75

Percent Gatherer-Collectors 0.23 -0.80 0.88 0.57 -0.05 0.04 -0.38

Biotic Index 0.68 0.03 0.53 0.26 -0.28 0.97 0.28

2. Replicate sites and include a minimum of three samples 

per site. Because watersheds differ both in the tendency 

to incise (Chapters 3, 4, and 5) and in water chemistry 

(Amacher and others 2004), sites should be replicated 

across watersheds. Spatial variability in groundwater 

inputs, even within seemingly similar stream reaches, necessitates multiple samples per site.

3. Collect data across multiple years and seasons. Stream 

flow is highly variable both among and within years 

in Great Basin watersheds. Our data show that aquatic 

invertebrates are highly responsive to the variability in 

stream flow. To ensure an accurate representation of the 

diversity and abundance of different taxa, it is necessary 

to sample aquatic invertebrates both among and within 

years.

4. Use multivariate tests such as MRPP or non-parametric 

MANOVA to ecologically and statistically validate 

multimetric index results. Multimetric and multivariate methods have different means of examining benthic 

communities. Since multimetric bioassessment methods 

can fail to recognize fundamental benthic community 

dynamics that are critical for informed managerial decisionmaking, multivariate testing provides a crucial 

technique for verifying multimetric results. Multimetric 

methods compare metrics that are commonly composed 

of groups of taxa while the multivariate method used in 

this study examines the entire population at greater resolution—taxon by taxon.

5. Generalized linear mixed models (GLMM) may offer 

another tool for describing population responses to environmental effects and for describing those population 
94 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

distributions. GLMM could be used in place of the multiple 

ANOVAs and correlation calculations performed in this 

study and may not require distribution transformations.

References

Amacher, Michael C.; Kotuby-Amacher, Janice; Grossl, Paul R. 

2004. Effects of natural and anthropogenic disturbances on 

water quality. In: Chambers, Jeanne C.; Miller, Jerry, R., eds.

Great Basin Riparian Ecosystems—Ecology, Management and 

Restoration. Covello, CA: Island Press: 162-195.

Barbour, Michael T.; Gerritsen, Jeroen; Snyder, Blaine D.; Stribling, 

James B. 1999. Rapid bioassessment protocols for use in streams 

and wadeable rivers: periphyton, benthic macroinvertebrates 

and fish, 2nd ed. EPA 841-B-99-002: Washington, DC: U.S. 

Environmental Protection Agency, Office of Water.

Beche, Leah A.; Resh, Vincent H. 2007. Biological traits of 

benthic macroinvertebrates in California mediterranean-climate 

streams: long-term annual variability and trait diversity patterns. 

Fundamental and Applied Limnology. 169: 1-23.

Boulton, Andrew J.; Peterson, Christopher G.; Grimm, Nancy B.; 

Fisher, Stuart G. 1992. Stability of an aquatic macroinvertebrate 

community in a multiyear hydrologic disturbance regime. 

Ecology. 73: 2192-2207.

Burgherr, P.; Ward, J.V.; Robinson, C.T. 2002. Seasonal variation 

in zoobenthos across habitat gradients in an alpine glacial 

floodplain. Journal of the North American Benthological Society. 

21: 561-575.

Chambers, Jeanne C.; Miller, Jerry R. 2004. Restoring and 

maintaining sustainable riparian ecosystems: the Great Basin 

ecosystem management project. In: Chambers, Jeanne C.; Miller, 

Jerry R., eds. Great Basin Riparian Ecosystems—Ecology, 

Management and Restoration. Covello, CA: Island Press: 1-23.

California Department of Fish and Game, Aquatic Bioassessment 

Laboratory, Water Pollution Control Laboratory [CA DFG]. 

2003. California stream bioassessment procedures. Rancho 

Cordova, CA. 11 p.

Hannah, David; Brown, L.E.; Milner, A.M.; Gurnell, A.M.; 

McGregor, G.R.; Petts, G.E.; Smith, B.P.G.; Snook, D.L. 2007. 

Integrating climate-hydrology-ecology for alpine river systems. 

Aquatic Conservation: Marine and Freshwater Ecosystems. 17: 

636-656.

Herbst, David B.; Silldorff, Erik L. 2006. Comparison of the 

performance of different bioassessment methods: similar 

evaluations of biotic integrity from separate programs and 

procedures. Journal of the North American Benthological 

Society. 25(2): 513-530.

Hubbard, J.P. 1977. Importance of riparian ecosystems: biotic 

considerations. In: Johnson, R.R.; Jones, D.A., eds. Importance, 

preservation, and management of riparian habitat: A symposium. 

Gen. Tech. Rep. RM-43. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service: 14-18.

Hunter, D.; Reuter, J.; Goldman, C.R. 1993. Lake Tahoe interagency 

monitoring program, draft standard operating procedures. 

University of California, Davis. 79 p.

Jenson, S.E.; Platts, W.S. 1990. Restoration of degraded riverine/

riparian habitat in the Great Basin and Snake River regions. In: 

Kusler, J.A.; Kentula, M.E. eds. Wetland creation and restoration: 

the status of the science. Covello, CA: Island Press: 367-398.

Karr, James R.; Chu, Ellen W. 1999. Restoring life in running waters: 

better biological monitoring. Washington, DC: Island Press. 

207 p.

Kennedy, Tom B.; Merenlender, A.M.; Vinyard, G.L. 2000. A 

comparison of riparian condition and aquatic invertebrate 

community indices in central Nevada. Western North American 

Naturalist. 60: 255-272.

Kerans, B.L.; Karr, J.R.; Ahlstedt, S.A. 1992. Aquatic invertebrate 

assemblages: spatial and temporal differences among sampling 

protocols. Journal of the North American Benthological Society. 

11(4): 377-390.

Linke, Simon; Bailey, R.C.; Schwindt, J. 1999. Temporal variability 

of stream bioassessments using benthic macroinvertebrates. 

Freshwater Biology. 42: 575-584.

Maloney, Kelly O.; Feminella, Jack W. 2006. Evaluations of 

single- and multi-metric benthic macroinvertebrate indicators 

of catchment disturbance over time at the Fort Benning military 

installation, Georgia, USA. Ecological Indicators. 6: 469-484.

Mast, M.A.; Clow, D.W. 2000. Environmental characteristics and 

water quality of hydrologic benchmark network stations in the 

western United States. Circular 1173-D. U.S. Geological Survey. 

114 p.

McCune, Bruce; Grace, J.B. 2002. Analysis of ecological 

communities. Gleneden Beach, OR: MjM Software Design. 

300 p.

Merritt, Richard W.; Cummins, Kenneth W. 1996. An introduction 

to the aquatic insects of North America, 3rd ed. Dubuque, IA: 

Kendall/Hunt Publishing Co. 862 p.

Myers, Marilyn J.; Resh, Vincent. H. 2002. Trichoptera and other 

macroinvertebrates in springs of the great basin: species 

composition, richness, and distribution. Western North American 

Naturalist. 62: 1-13.

Parsons, M.; Norris, R.H. 1996. The effect of habitat-specific 

sampling on biological assessment of water quality using a 

predictive model. Freshwater Biology. 36: 419-434.

Post, D. 2005. Dytiscidae of California. Proceedings from CAMLnet 

taxonomy workshop. California State University, Chico.

Rehn, Andrew C.; Ode, Peter R.; Hawkins, Charles P. 2007. 

Comparisons of targeted-riffle and reach-wide benthic 

macroinvertebrate samples: implications for data sharing 

in stream-condition assessments. Journal North American 

Benthological Society. 26: 332-348.

Robinson, C.T.; Uehlinger, H.; Hieber, M. 2001. Spatio-temporal 

variation in macroinvertebrate assemblages of glacial streams in 

the Swiss Alps. Freshwater Biology. 46: 1663-1672.

Saab, V.; Groves, C. 1992. Idaho’s migratory birds: description, 

habitats, and conservation. Nongame Wildlife Leaflet 10. Boise, 

ID: Idaho Department of Fish and Game. 16 p.

Sada, Donald W.; Fleishman, E.; Murphy, D.D. 2005. Associations 

among spring-dependent aquatic assemblages and environmental 

and land use gradients in a Mojave Desert mountain range. 

Diversity Distributions. 11: 91-99.

Sanders, Laura L. 1998. A manual of field hydrogeology. Upper 

Saddle River, NJ: Prentice-Hall Inc. 381 p.

Stewart, Kenneth W.; Stark, B.P. 2002. Nymphs of North American 

stonefly genera (Plecoptera), 2nd ed. Toronto, Canada: University 

of Toronto Press, Inc. 457 p.

Thorp, Jim H.; Covich, A.P. 1991. Ecology and classification of 

North American freshwater invertebrates. San Diego, CA: 

Academic Press, Inc. 911 p.

Wiggins, Glenn B. 1996. Larvae of the North American caddisfly 

genera (Trichoptera), 2nd ed. Columbus, OH: The Caddis Press. 

457 p.

Yoder, Chris O.; Rankin, Edward T. 1998. The role of biological 

indicators in a state water quality management process. 

Environmental Monitoring and Assessment. 51: 61-88.

Zimmerman, Gregory M.; Goetz, Harold; Mielke, Paul W., Jr. 1985. 

Use of an improved statistical method for group comparisons to 

study effects of prairie fire. Ecology. 66(2): 606-611.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 95

Introduction

Great Basin riparian meadows are highly sensitive to both natural and anthropogenic disturbance. As detailed in earlier chapters, streams in the central Great Basin 

have a natural tendency to incise due to their geomorphic 

history (Miller and others 2001, 2004). Anthropogenic 

disturbances, including overgrazing by livestock, mining activities, and roads in the valley bottoms, have increased both 

the rate and magnitude of incision (Miller and others 2004; 

Chambers and Miller 2004). Stream incision within meadow 

ecosystems alters channel structure and function and causes 

a decrease in the water table adjacent to the stream. Because 

meadow vegetation is closely related to groundwater depth 

(Allen-Diaz 1991; Castelli and others 2000; Chambers and 

others 2004a; Naumburg and others 2005; Dwire and others 2006; Loheide and Gorelick 2007), stream incision can 

result in changes in species composition and, following catastrophic incision, loss of the meadow ecosystem (Wright 

and Chambers 2002; Chambers and others 2004b). Wet 

and mesic meadow communities are particularly sensitive 

to lowered water tables (Castelli and others 2000) and typically decrease in extent following a drop in the water table. 

Decreases in groundwater levels also can lead to encroachment of upland vegetation and, ultimately, to conversion to 

Artemisia (sagebrush) dominated communities (Groeneveld 

and Or 1994; Wright and Chambers 2002; Darrouzet-Nardi 

and others 2006). Other disturbances such as small mammal burrowing (Berlow and others 2002) or overgrazing by 

livestock (Wright and Chambers 2002) can accelerate shrub 

encroachment. Once water tables have been lowered, the 

ecological potential to support a given meadow vegetation 

type changes and alternative management strategies must 

be considered (Chambers and Linnerooth 2001; Wright and 

Chambers 2002). An understanding of the vulnerability of 

different types of meadows to incision is necessary to prioritize restoration and management efforts.

There has been extensive work on the effects of reachscale disturbances on meadow degradation—in particular on 

the impact of overgrazing by livestock on plant communities (Fleischner 1994; Green and Kaufffman 1995; Dobkin 

and others 1998; Martin and Chambers 2001; Kauffman 

and others 2004; Kluse and Allen-Diaz 2005; Jackson and 

Allen-Diaz 2006; Coles-Ritchie and others 2007) and on 

channel morphology (Fleischner 1994; Trimble and Mendel 

1995; Sidle and Sharma 1996; Allen-Diaz and others 1998). 

There is considerably less information on the role that larger, watershed-scale processes play in governing reach-scale 

sensitivity to disturbance. Recent research in the Great Basin 

indicates that watersheds differ in their sensitivity to disturbance and that sensitivity is influenced by morphometry 

and geology (Germanoski and Miller 2004, Chapters 2 and 

5). Drainage basins with morphologic characteristics that 

lead to rapid runoff are more sensitive to disturbance within the central Great Basin (Germanoski and Miller 2004). 

These same characteristics control the pattern and composition of riparian vegetation in the watersheds (Chambers 

and others 2004b). Similarly, research on process domains 

(Montgomery 1999) and river styles (Brierley and Fryirs 

2000) demonstrates that, within watersheds, there are different zones that experience different stream power and 

that are dominated by different disturbance regimes and environmental characteristics. This prior work indicates that 

although all central Great Basin stream systems are prone to 

incision, they are not all equally vulnerable.

In this chapter, we expand on previous work to create 

a system for grouping meadows based on watershed-scale 

morphometric characteristics that are indicative of the rate 

and magnitude of runoff. Although stream gages are sparse 

in the Great Basin, prior research in the region indicated that 

it is possible to correlate discharge and watershed characteristics (Hess 2002). We had four main objectives: (1) develop 

a categorization of meadows within the central Great Basin 

based on both their watershed- and reach-scale characteristics; (2) sample and describe previously identified vegetation 

types and their species composition and relative abundance 

within the meadows; (3) determine how vegetation and 

other indicators of meadow degradation such as channel 

depth, number of knickpoints, and bank stability relate to 

the watershed and reach based categorization; and (4) provide managers with necessary information for analyzing 

meadows and for determining whether active management 

is needed.

Description of Study Meadows

The study area included 33 watersheds located in 6 mountain ranges in the central Great Basin (Shoshone, Toiyabe, 

Chapter 7: Charcterization of Meadow 

Ecosystems Based on Watershed and Valley 

Segment/Reach Scale Characteristics

Wendy Trowbridge, Jeanne C. Chambers, Dru Germanoski, 

Mark L. Lord, Jerry R. Miller, and David G. Jewett
96 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Toquima, Monitor, Roberts, and Hot Creek mountains), an 

area of 15,000 square km2 (fig. 1.7). The whole watershed 

average annual precipitation ranged from 28 to 50 cm (Daly 

and Taylor 1998). Most of the precipitation falls as snow in 

the winter. Winter storms move from west to east across the 

study site, so larger, more western ranges tend to be wetter 

than small ranges farther east. The Toiyabes are the wettest 

and the Hot Creeks are the driest. In addition, west facing 

watersheds catch more precipitation than east facing watersheds. Summer precipitation is related to monsoonal moisture 

that moves north off of the Gulf of California. It is highly 

localized and variable. For both years of the study, precipitation at the Big Creek snow pack telemetry (SNOTEL) site 

located near the top of the watershed was near the long-term 

average—69.1 cm and 65.0 cm, respectively, compared to a 

26-year average of 67.6 cm (NWCC 2007).

The 56 study meadows are montane meadows that are 

located in small upland watersheds. The watersheds range in 

size from 460 ha to 9500 ha and reach maximum elevations 

of 2275 to 3495 m. The size of the meadows range from 

0.5 ha to 15 ha with a median of 2 ha, and elevations range 

from 2023 to 2631 m. Fifty-one of the meadows are on The 

Humboldt-Toiyabe National Forest. The remaining five are 

privately owned. The primary land use on all of these meadows is grazing of cattle and sheep. Not all meadows were 

grazed in the two years of the study, but all were intensively 

grazed at some point in the last 150 years of human habitation in the area (Jensen and Platts 1990). Some meadows are 

used sporadically for camping, hunting, and fishing, while 

others are rarely visited. There are existing roads to all but 

four of the meadows, but they are all unpaved and many 

are not maintained. The surrounding vegetation is primarily sagebrush steppe with pinyon and juniper woodlands in 

some watersheds. Mountain mahogany and limber pine occur at the highest elevations.

Methods

Meadows were selected to represent a range of current 

conditions, positions in the watersheds, size of watersheds, 

and land management types (from wilderness to privately 

owned). Some watersheds had multiple meadows (as many 

as five) while many had only one. Figure 1.7 shows the locations of the meadows. The variables measured describe 

the physical processes that control meadow characteristics, 

the biotic characteristics of the meadows, and the ecological condition of the meadows (table 7.1). Meadow condition 

variables were related to plant communities, knickpoints, 

and incision.

Table 7.1. List of the study variables and how they were measured and classified. The reach and watershed characteristics were 

used to create the meadow categorization.

Variable Measurement method Variable type

Meadow slope long profile reach characteristics

Number of knickpoints long profile reach characteristics

Knickpoint height long profile Indicators of meadow degradation

Knickpoint slope long profile Indicators of meadow degradation

Depth of channel in meadow cross section Indicators of meadow degradation

Percent vertical bank long profile Indicators of meadow degradation

Number of springs count reach characteristics

Sinuosity within the meadow long profile reach characteristics

Extent of each plant community GPS vegetation communities

Meadow size GPS reach characteristics

Length of channel in the meadow long profile reach characteristics

Total watershed area GIS watershed characteristics

Watershed area above meadow GIS watershed characteristics

Watershed area above 2743 m GIS watershed characteristics

Watershed area above 2438 m GIS watershed characteristics

Total channel length above meadow GIS watershed characteristics

Length of main channel above meadow GIS watershed characteristics

Length of the whole channel GIS watershed characteristics

Maximum watershed elevation GIS watershed characteristics

Elevation of top of main channel GIS watershed characteristics

Average precipitation GIS (PRISM) watershed characteristics

Meadow elevation GIS watershed characteristics

Mountain range categorical variable watershed characteristics

Watershed aspect (westness) = Sin(aspect +180) watershed characteristics

Watershed aspect (southness) = Cos(aspect +180) watershed characteristics

Relief = Max watershed elevation—Meadow elevation watershed characteristics

Channel relief = Elevation of top of channel—Meadow elevation watershed characteristics

Drainage density = Total channel length above meadow / Area above meadow watershed characteristics

Position = Length of channel above meadow / Length of whole channel watershed characteristics

Shape of the whole watershed = Channel length above meadow2/ Area above meadow watershed characteristics

Shape of the watershed above meadow = Total watershed area / length of whole channel watershed characteristics

Total watershed precipitation = Average precipitation X Watershed area above meadow watershed characteristics
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 97

Data Collection

Field work was conducted over the course of two field 

seasons (2005 and 2006). For each meadow, a long profile 

of the stream channel and representative cross sections were 

surveyed. At each survey point along the long profile, bank 

stability (vertical versus continuous slope) was recorded. The 

maximum number of terraces was counted and knickpoints 

were identified and surveyed. Channel slope and sinuosity 

within the meadow were calculated from the survey data.

Three cross sections were surveyed in each meadow 

reach and in the reaches above and below the meadow. 

Points were surveyed or measured at breaks in slope, water 

surface, thalweg, and meadow surface on both sides of the 

channel. Channel depth was used as a measure of incision 

and was calculated by subtracting thalweg elevation from 

average meadow surface elevation.

A GPS unit was used to delineate plant communities 

and the meadow outline. The seven main plant communities were wet meadow (wet), mesic meadow (mesic), dry 

meadow (dry), dry shrub, willow, rose, and aspen (modified 

from Manning and Padgett 1995 and Weixelman and others 

1996; Appendix 7.1). Areas were calculated for each plant 

community and the entire meadow. Plant community data 

are presented as a percentage of the total meadow area, excluding aspen, which is not strictly a meadow community. 

Plant communities were described using randomly located 

0.25-m plots (between 15 and 20 per community, depending 

on community size). At each plot, aerial cover was estimated 

for all species using cover classes (trace, 1-5, 6-10, 11-25, 

26-50, 51-75, 75-95, and 95-100 percent). Springs also were 

mapped using the GPS unit and were measured with a tape. 

Springs without geomorphic expression (localized and likely ephemeral wet spots) were mapped but not measured to 

minimize the effect of sampling date.

Watershed-level variables were measured using USGS 

topographic maps and DEMs in ArcGIS. Watersheds were 

delineated on 7.5-minute USGS topographic maps using 

ArcGIS software. Hawth’s Analysis Tools (Beyer 2004) 

were used to measure total watershed area, watershed area 

above the meadow, watershed areas above the 2438-m and 

2743-m contours and channel lengths. Relief and maximum 

elevations were determined by picking spot elevations from 

topographic maps. For this study, watersheds were defined 

as the catchment area above each meadow and the catchment 

area of the whole watershed above the terminal alluvial fan.

The Parameter-elevation Regressions on Independent 

Slopes Model (PRISM; a product of the Oregon Climate 

Service) was used to estimate average yearly precipitation throughout Nevada. This program models large-scale 

orographic and climatic processes and creates a map with 

isoclines of precipitation for the entire state. Total precipitation and watershed average precipitation were calculated by 

overlaying watershed area polygons on the PRISM map of 

annual precipitation.

Data Analysis

The raw data were transformed using a Box-Cox transformation. The resulting transformed data were then 

standardized and tested for normality using a KolmogorovSmirnov goodness-of-fit test. Principle Components 

Analysis (PCA) and Nonmetric Multidimensional Scaling 

(NMDS) were used to identify structure within watershed 

characteristics (see table 7.1 for watershed characteristics) 

and to create groupings of meadows with similar characteristics. We plotted PCA axis 1 versus 2 and 1 versus 3 and 

the two main nonmetric multidimensional scaling axes in 

order to visualize groupings based on the watershed characteristics. The plots were examined for natural groupings and 

breaks in the data that remained consistent across all three 

plots. Bar charts and one-way ANOVA analyses were used 

together with the eigenvectors to illustrate which variables 

were driving the groupings.

Vegetation communities and their characteristic species 

had been identified previously in this area (Manning and 

Padgett 1995; Weixelman and others 1996) and the vegetation mapping and sampling were based on these known 

community types (Appendix 7.1). To verify that these communities were distinct, we used MRPP using species cover 

values for all sampled plots. All analyses were carried out 

using PC-ORD (McCune and Mefford 1999). In addition, 

importance values for individual species within the community types were calculated using cover and presence absence 

data and add to 100 percent.

The groups that were created with the watershed characteristics were related to both the vegetation community types 

and physical indicators of meadow condition data (e.g., 

knickpoint slope and depth of channel) by calculating and 

graphing group averages and standard deviations. One-way 

ANOVAs were used to test for differences in watershed 

characteristics, vegetation, and meadow condition among 

the groupings.

The watershed and meadow geomorphic characteristics, 

the channel characteristics within the meadow, and the percentage of each vegetation type are summarized for each of 

the 56 study meadows in Appendices 7.2 through 7.5.

Results and Discussion

Watershed Characteristics

The meadows were divided into five groups based on 

measured watershed-and reach-level characteristics (table 7.2; fig. 7.1). These groups were selected based on the 

grouping of the meadows in both the PCA and NMDS diagrams (fig. 7.1). Groups 4 and 5 were distinct in all three 

projections. Groups 1 through 3 formed a continuum along 

axis 1 in the PCA and axis 2 in the NMDS. The PCA diagram of axis 1 versus axis 3 showed a better separation 

between these groups, and it led to the decision to create 
98 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

three groups. Figure 7.2 illustrates the relationship between the groups and the variables used to create them. 

Watershed area above the meadow was the most important 

driver of the groupings, but other variables were important 

for particular groups. For example, post hoc tests showed 

that meadow elevation was not significantly different for 

Groups 1 through 4 but Group 5 meadows were at much 

higher elevations. Groups 1 through 3 represented a continuum from meadows at the bottom of large, high-elevation 

watersheds to meadows that were part of the way up smaller, lower-elevation watersheds rather than actual distinct 

groups. This was essentially a gradient of water capture. In 

the PCA analysis, these three groups lined up along the first 

axis (fig. 7.1). The eigenvectors of the first axis showed 

that the length of the main channel above the meadow, total channel length, total watershed precipitation, watershed 

area above the meadow, relief, area above 2743 m, and 

maximum watershed elevation were the variables that were 

most highly correlated with this axis (table 7.3). This axis 

explained 37 percent of the total variability. These variables were all closely related to the watershed’s ability to 

capture water and transport sediment.

The interpretation of the second PCA axis was more 

complicated. Group 5 was similar to Groups 3 and 4 with 

respect to axis 1, but it was distinct with respect to axis 2. 

Group 5 meadows were higher-elevation, steeper meadows 

at the top of their watersheds. They were also in the drier 

(less average precipitation) parts of the study area. Group 4 

meadows were mostly in the northern Toiyabe Mountains, 

which were the wettest (highest average precipitation) 

area. As a result, these meadows were bigger than their axis 

1 scores (water capture ability) suggested. Groups 4 and 5 

represented more of a departure from the main discharge 

pattern and, thus, form more distinct groups. Table 7.3 and 

fig. 7.2 show that meadow elevation, mountain range, watershed shape, and position in watershed were the variables 

most highly correlated with this axis. This axis explained 

14 percent of the total variability.

Table 7.2. Categorization of the 56 meadows and group-averaged values for the most heavily weighted variables. Numbers in 

parentheses are standard deviations.

Group

Variable 1 2 3 4 5

Birch 1 Lebeau Corcoran 1 Meadow 1 Six Mile 1

Birch 2 San Juan 2 Corcoran 2 Meadow 2 Six Mile 2

Kingston 0 Green Monster Corcoran 3 Birch Trib Fandango 1

Kingston 1 South Crane Corcoran 4 Cahill 2 Fandango 2

Kingston 3 San Juan 1 Corcoran 5 Cahill 3 East Dobbin

Mosquito Mohawk Corcoran main 1 Emigrant 2 West Dobbin

Barley 1 Danville Corcoran main 2 Corral 2 Little Cow

Indian Valley Big Creek Corcoran main 3 Johnson 2 Stargo

Wadsworth 1 Round Mountain Johnson 3 Wadsworth 2

Cloverdale Willow (Monitors) Emigrant 1 Wadsworth 3

Cottonwood Barley Tributary Red Canyon Wadsworth 4

Washington West Northumberland Johnson 1

Corral 1

Watershed area above 4421 (2676) 1381 (670) 631 (312) 294 (192) 129 (109)

meadow (ha)

Area above 2743 m (ha) 1356 (1505) 389 (199) 32.9 (21) 1.0 (2) 55.2 (51)

Length of channel above 11.84 (4.64) 6.63 (1.78) 4.25 (0.79) 2.63 (0.63) 1.75 (0.78)

meadow (km)

Percent of channel above 64.3% (0.19) 74.0% (0.19) 57.1% (0.13) 47.6% (0.22) 18.5% (0.08)

meadow

Watershed average 44.1 (7.5) 40.1 (6.7) 39.5 (4.9) 43.5 (3.9) 35.0 (4.7)

precipitation (cm)

Relief (max elevation- 1090 (184) 957 (172) 591 (90) 366 (140) 409 (170)

meadow elevation) (m)

Maximum watershed 3315 (187) 3208 (136) 2927 (93) 2595 (170) 2973 (178)

elevation (m)

Meadow elevation (m) 2225 (68) 2250 (113) 2335 (61) 2229 (172) 2563 (50)

Meadow slope (%) 1.30% (0.01) 4.35% (0.01) 4.70% (0.01) 6.65% (0.05) 7.94% (0.03)

Meadow size (ha) 6.81 (4.38) 3.64 (2.63) 1.73 (0.97) 2.80 (1.41) 1.47 (1.00)

Meadow sinuosity 1.31 (0.20) 1.10 (0.06) 1.09 (0.04) 1.07 (0.04) 1.08 (0.03)

Number of springs per 10.0 (8) 5.3 (4) 5.2 (6) 3.7 (3) 3.6 (4)

meadow
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 99

Meadow Group Characteristics

Group 1 meadows were located at or near the base of 

large wet watersheds with high maximum elevations and 

high relief. These were the highest discharge meadows, so 

it is not surprising that channel depths were greatest and 

percent vertical bank was highest in this group (fig. 7.5; 

table 7.3). These were large, flat meadows that tended to 

have numerous springs with deep channels, suggesting 

previous incision. Group 1 meadows had few knickpoints, 

which were not particularly large. This suggested that 

knickpoints move quickly through these meadows. Many 

of the Group 1 meadows had willows, but they were typically a small percentage (average 24 percent) of the overall 

cover (fig. 7.3). There was another group of even larger, 

flatter, lower-elevation meadows that were privately owned 

and actively managed. They were not included in this study 

because of management differences and permission issues.

Group 2 meadows also were located near the base of 

their watersheds, but these watersheds were smaller, lower 

relief, and drier than Group 1 watersheds. Many Group 

2 meadows were still large, but there was more variability in this group. They were less flat, occurred at slightly 

higher elevations, and had fewer springs (table 7.3). Many 

of these meadows were dominated by willows (average 

45 percent cover) and tended to have less wet meadow vegetation and more dry shrub vegetation (fig. 7.3). Many of 

these meadows also had deeper channels, although again 

there was more variability. Some meadows in this group 

were relatively unincised with water flowing in multiple 

channels across the surface while others had deeply incised 

channels. Group 2 meadows also had more knick points 

than Group 1 meadows.

Group 3 meadows were higher in their watersheds, and 

these watersheds had even lower maximum elevations and 

were smaller and slightly steeper than watersheds in the 

previous groups (fig. 7.2; table 7.3). These meadows were 

characterized primarily by substrates of volcanic origin, had 

relatively low discharge, and were dominated by a series of 

meadows in the Toquima Mountains (Appendices 7.2 and 

7.3). Group 3 meadow plant communities were different 

from those in Groups 1 and 2. Willows were rare in this 

group (average 5 percent cover) and wet and mesic communities dominated (fig. 7.3). The stream channels within 

many of these meadows were completely unincised, and 

where incision had occurred, channel depths were small. In 

this respect, Group 3 was similar to Groups 4 and 5.

Figure 7.1. Diagrams of the first two PCA axes, the first and third axes for the NMDS, and the main axes for the NMDS. The 

final groups shown and the symbols are listed in the bottom left.
100 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Figure 7.2. Mean and standard error for significant predictor variables by meadow group. Standardized values 

were used in these figures. P values show differences among groups from one-way ANOVAs. Groups with 

unlike letters are significantly different (p<0.05).
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 101

Group 4 meadows were in small, low-elevation, low-relief watersheds. Their position in the watershed was similar 

to Group 3, but they were at lower elevations and tended to 

be larger than Group 3 meadows. Group 4 meadows mostly surrounded the town of Austin at the north end of the 

Toiyabe range, which, because of its proximity to Bunker 

Hill (3489 m), tends to have higher precipitation. Group 4 

plant communities were drier than Group 3 meadows with 

more of the dry meadow community and less of the wet 

meadow community. These meadows were similar to those 

in Group 3 with respect to channel incision. Many Group 

4 meadows were unincised or had unincised reaches, and 

where incision had occurred it was relatively shallow.

Group 5 meadows were small, high-elevation, high-slope 

meadows that were located near the top of their watersheds. 

We sampled these meadows in the Monitor and Hot Creek 

ranges, but this type of meadow existed throughout all five 

of the main mountain ranges. This was the most common 

meadow type in the central Great Basin. These meadows 

occur primarily in high-elevation watersheds around Bunker 

Hill, Little Table Mountain, Table Mountain, and in the Hot 

Creeks. Because of meadow position in the watershed, the 

capacity to capture water and deliver it to the meadow was 

limited. The meadows that we sampled in this group were 

the driest of the five groups. The mesic and dry shrub communities were dominant in these meadows with very little 

wet meadow and no willows. The average wet meadow cover was 10 percent and 5 of the 11 meadows in this group had 

no wet meadow component.

Plant Community Characteristics

Seven major plant communities were identified from 

the literature based on depth to groundwater and vegetation structure: wet meadow, mesic meadow, dry meadow, 

dry shrub, willow, rose, and aspen. Other authors (Manning 

and Padgett 1995; Weixelman and others 1996) have created more community groups based on species composition 

Table 7.3. The eigenvectors of the first four PCA axes that show which variables are most highly correlated with 

the different axes. Eigenvectors of greater than 0.24 or less than -0.24 are shaded for emphasis.

Eigenvectors NDMS scores

Variable 1 2 3 1 2

Total watersed precipitation -0.2847 -0.1220 0.0244 -0.0212 0.1511

Length of main channel above meadow -0.2843 -0.1220 -0.0852 -0.0226 0.1541

Watershed area above meadow -0.2828 -0.1063 0.0205 -0.0174 0.1509

Total channel length above meadow -0.2805 -0.0561 0.0282 -0.0095 0.1512

Watershed area above 2438 m -0.2802 0.0631 0.0373 0.0242 0.1449

Relief -0.2732 0.0188 -0.2038 0.0067 0.1469

Channel relief -0.2556 0.0364 -0.2448 0.0048 0.1385

Area of the whole watershed -0.2035 0.1194 0.2072 0.0393 0.0998

Watershed area above 2743 m -0.2597 0.2002 -0.1163 0.0457 0.1389

Maximum watershed elevation -0.2392 0.2340 -0.1120 0.0535 0.1255

Elevation of top of main channel -0.2037 0.2734 -0.1666 0.0557 0.1090

Drainage density -0.0182 -0.2831 -0.0251 -0.0466 0.0022

Meadow elevation 0.1167 0.3889 0.1593 0.0840 -0.0656

Shape of the whole watershed -0.0044 0.3083 -0.1034 0.0493 0.0140

Mountain range 0.1177 0.3236 0.0220 0.1123 -0.1065

Length of the whole main channel -0.1992 0.2503 0.2047 0.0625 0.1006

Position -0.1721 -0.2731 -0.2783 -0.0573 0.0991

Sinuosity within the meadow -0.1755 0.1607 0.2790 0.0411 0.0830

Southness -0.0737 -0.1827 0.2510 -0.0289 0.0264

Westness -0.0448 0.1111 -0.2815 0.0134 0.0277

Meadow size -0.1352 -0.1483 0.2626 -0.0184 0.0651

Length of channel in the meadow -0.0830 -0.1646 0.2741 -0.0237 0.0359

Shape of the watershed above meadow -0.0531 -0.0617 -0.3738 -0.0175 0.0371

Meadow slope 0.2045 0.0761 -0.2541 0.0139 -0.1081

Number of springs -0.0983 0.0758 0.0505 0.0102 0.0447

Average precipitation -0.0931 -0.1980 0.0269 -0.0452 0.0431

Hypsometric integral -0.0040 -0.0636 0.1397 -0.0074 0.0058
102 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Figure 7.3. Percent cover (mean and standard error) for the five vegetation communities

by meadow group. Standardized values were used in these figures. P values show

differences among groups from one-way ANOVAs. Groups with unlike letters are

significantly different (p<0.05).

-1.0 

-0.5 

0.0 

0.5 

1.0 

1.5 

1 2 3 4 5 

a a 

b 

b b 

Willow 

p = 8.8 x 10-12 

-1.0 

-0.5 

0.0 

0.5 

1.0 

1.5 

1 2 3 4 5 

a 

a,b a,b 

b 

a,b 

Wet 

p = 0.00782 

-1.0 

-0.5 

0.0 

0.5 

1.0 

1.5 

1 2 3 4 5 

Mesic 

p = 0.19596 

-1.0 

-0.5 

0.0 

0.5 

1.0 

1.5 

1 2 3 4 5 

Dry shrub 

p = 0.34523 

-1.0 

-0.5 

0.0 

0.5 

1.0 

1.5 

1 2 3 4 5 

a 

a,b 

b 

b 

a,b 

Dry 

p = 0.00376 Meadow Groups 

Meadow Groups 

Standard scores Standard scores Standard scores 

and have related them to various physical characteristics 

like soils and elevation (Appendix 7.1). Because we were 

primarily interested in the relationship between vegetation 

and groundwater depth, we based our grouping on that used 

by Castelli and others (2000) who also studied this relationship. Results of the MRPP test show that there are significant 

differences among these groups based on species cover 

(p<0.0001, A = 0.168, and n = 3550). The large sample size 

was likely responsible for biasing the p-value downward, 

but the A statistic was typical of plant community data. The 

dry meadow and mesic meadow communities were the most 

similar based on their average distance.

Aspen groves were sometimes associated with meadows 

(14% of meadows), but we did not categorize them as a 

meadow community because they rely on different sources 

of water. Thus, aspen patches were mapped but not sampled. 

All of the meadows that were associated with aspen patches 

were in the northern Toiyabe Mountains.

The remaining six communities were found throughout 

all of the mountain ranges. The exact species composition 

changed from meadow to meadow across mountain ranges 

and with elevation, but the primary indicator species were 

consistent. Table 7.4 shows the average species cover and 

importance value of the main species in each community. 

Trends in life history groups also were important community indicators. As the plots became drier, rushes and sedges 

were replaced by forbs and then grasses. Finally, in the driest 

plots, shrubs dominated with dry meadow vegetation in the 

understory (fig. 7.4).

The wet meadow community occurred in areas that were 

supported by groundwater seeps or springs or at the bottom 

of meadows where water tables were highest. In these communities, groundwater is at or near the surface (typically 

within 30 cm) during June and July (Castelli and others 

2000; Chambers and others 2004b). Eighty percent of the 

meadows that we sampled contained the wet meadow community. Rushes and sedges were the dominant life history 

Figure 7.3. Percent cover (mean and 

standard error) for the five vegetation 

communities by meadow group. 

Standardized values were used in these 

figures. P values show differences 

among groups from one-way ANOVAs. 

Groups with unlike letters are 

significantly different (p<0.05).
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 103

group (total importance value [IV] = 66%). Carex (IV = 

53%) was the most common genus in this community type 

and Carex nebraskensis was the dominant species (IV = 

48%). Forbs (IV = 21%) and grasses (IV = 12%) were comparatively minor constituents.

The mesic meadow community was one of the most common communities. It was present in 96% of the meadows 

that we sampled. Where it was found, it represented a relatively high percentage of the meadow cover (25%). Past 

research in this area indicated that water table depths for this 

community ranged from 30 to 80 cm (Chambers and others 

2004b). Juncus balticus was the most common species in 

this community. It was found in 84% of plots, but because of 

its growth form it only represented an average of 11% of the 

cover. Although rushes and sedges were an important part 

of this community, their importance value (IV = 33%) was 

less than that of the forbs (IV = 41%). Grasses also played a 

larger role in this community than in the wet meadow community (IV = 25%). The non-native grass Poa pratensis was 

largely responsible for this increase.

The dry meadow community was comparatively rare. 

Only 45% of meadows had this community, and where it 

was present, it was a relatively minor part of the total area 

(an average of 16%). Previous research indicated that this 

community occurred naturally on the landscape but increased in response to disturbances that resulted in lowered 

water tables (Wright and Chambers 2002). Water tables that 

can support this community under proper management range 

from about 80 to 120 cm (Wright and Chambers 2002). 

Grasses were the dominant growth form in this community 

Table 7.4. The most common species in each vegetation community, sorted by importance value (a combination of 

cover and presence data). N = native, I = introduced.

Mean cover Importance Native/ Life history

Species ± S. E. value Introduced category

Wet meadow

Carex nebrascensis 42 ± 1.0 48% N rush/sedge

Juncus balticus 3 ± 0.2 10% N rush/sedge

Mesic meadow

Juncus balticus 11 ± 0.4 18% N rush/sedge

Poa pratensis 5 ± 0.3 9% I grass

Carex nebrascensis 3 ± 0.3 6% N rush/sedge

Taraxacum officinale 2 ± 0.2 5% I forb

Iris missouriensis 3 ± 0.3 5% N forb

Achillea millefolium 2 ± 0.4 4% N forb

Poa secunda 2 ± 0.2 4% N grass

Symphyotrichum spathulatum 1 ± 0.1 3% N forb

Dry meadow

Poa pratensis 4 ± 0.4 8% I grass

Poa secunda 3 ± 0.4 8% N grass

Juncus balticus 2 ± 0.3 7% N rush/sedge

Carex douglasii 3 ± 0.4 7% N rush/sedge

Pascopyrum smithii 3 ± 0.4 7% N grass

Iris missouriensis 3 ± 0.4 6% N forb

Taraxacum officinale 1 ± 0.2 4% I forb

Erigeron divergens 1 ± 0.3 4% N forb

Leymus cinereus 2 ± 0.5 3% N grass

Achillea millefolium 1 ± 0.2 3% N forb

Dry shrub meadow

Artemisia tridentata 18 ± 0.8 24% N shrub

Chrysothamnus nauseosus 7 ± 0.6 8% N shrub

Chrysothamnus viscidiflorus 4 ± 0.4 7% N shrub

Juncus balticus 2 ± 0.2 5% N rush/sedge

Leymus triticoides 2 ± 0.2 4% N grass

Carex douglasii 2 ± 0.2 4% N rush/sedge

Poa pratensis 2 ± 0.2 4% I grass

Willow

Salix exigua 23 ± 1.7 20% N shrub/tree

Salix lutea 16 ± 1.7 13% N shrub/tree

Rosa woodsii 9 ± 1.1 10% N shrub

Poa pratensis 2 ± 0.3 4% I grass

Betula occidentalis 5 ± 1.1 4% N shrub/tree

Carex nebrascensis 3 ± 0.5 4% N rush/sedge

Juncus balticus 1 ± 0.1 4% N rush/sedge
104 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

(IV = 40%). Non-native grasses were planted in some watersheds after fire and as forage. Consequently, these grasses 

were often a significant constituent of this community (IV 

= 13%). Native species that characterized this community 

type included Poa secunda juncifolia, Pascopyrum smithii,

and Leymus cinereus, while introduced species included 

Thinopyrum intermedium and Bromus inermis. The species in this community were more variable from meadow to 

meadow than in other communities. As a result, there was no 

dominant species in this community. The ratio of grasses to 

sedges and rushes was the best descriptor, and it was significantly less in the wet meadow (0.19 to 1) and mesic meadow 

(0.75 to 1) than in the dry meadow community (2.13 to 1).

The dry shrub community had a shrub density similar to 

the surrounding upland community but had an understory of 

meadow species. This transitional community was present 

in 96% of meadows, and was one of the largest communities in most meadows (average 32% of total meadow area). 

Artemisia tridentata (subspecies tridentata and vaseyana) 

was the most common species in the community (IV = 

18%), but Chrysothamnus species were also important (IV = 

11%). The understory of this community was variable. Some 

patches were dominated by mesic meadow species, primarily Juncus balticus, and had fewer grasses. These patches 

also had more Chrysothamnus and Rosa woodsii. Other 

patches were more grass dominated with understory species 

similar to the dry meadow community. For the purposes of 

this report, these two patch types were lumped together as 

dry shrub.

The willow community was primarily found on terraces 

next to the stream channel. Overall, 54% of the meadows 

that we sampled had willows. Position in the watershed was 

an important predictor of willow presence. Of the meadows near the top of their watersheds (less than 45% of the 

stream length was above the meadow) only 20% had willows. The four meadows near the top of their watersheds 

that had willows only had small patches, representing 2% or 

less of total meadow cover. In contrast, 72% of meadows at 

the bottom of their watersheds had willows and of those with 

willows, the average meadow cover was 33%. Elevation 

was collinear with watershed position, but since there were 

willows at high-elevation (both outside of meadows and in 

meadows that were at the bottom of high-elevation watersheds), there was clearly no physiological constraint. The 

actual willow cover in these communities was variable, but 

they were often quite dense with very limited understory. 

The willow communities along the channel tended to have 

understories similar to the wet meadow community, but 

patches away from the stream were much drier.

The rose community was the rarest community with only 

14% of meadows having a distinct rose community. Rose 

patches in these meadows only made up 15% of the total 

cover. However, these statistics underestimated the importance of Rosa woodsii in these meadows because it was often 

a major constituent of the willow and dry shrub communities. Rose patches were often associated with the dry shrub 

community and had similar shrub and understory species to 

the dry shrub community. Overall, 57% of the meadows contained this species. In the patches where it was the dominant 

species, Rosa woodsii was quite dense (IV = 39%) and there 

was often limited understory. Rose generally is considered to 

be an indicator of disturbance in the Great Basin (Weixelman 

and others 1996; Chambers and others 2004a).

Indicators of Degradation

The relationships between the meadow groupings and the 

indicators of meadow degradation were complex (fig. 7.4). 

There were meadows with indicators of degradation in each 

group. The significant relationship between the knickpoint 

variables and the meadow groupings was driven by the 

comparative scarcity of knickpoints in Group 1 meadows. 

Figure 7.4. The change in the importance value of the four main life history groups

across the six vegetation communities. The understory of the willow and rose

communities are highly variable.

0 

0.1 

0.2 

0.3 

0.4 

0.5 

0.6 

mesic dry shrub willow rose 

forb grass shrub/tree rush/sedge 

Total Importance Value by functional group 

Figure 7.4. The change in the 

importance value of the four 

main life history groups across 

the six vegetation communities. 

The understory of the willow 

and rose communities are highly 

variable.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 105

Figure 7.5. Mean and standard error for variables that are indicative of meadow degradation by meadow group.

Standardized values were used in these figures. P values show differences among groups from one-way ANOVAs.

Groups with unlike letters are significantly different (p<0.05).

-1.7 

-1.2 

-0.7 

-0.2 

0.3 

0.8 

1.3 

1 2 3 4 5 

Number of Knickpoints 

p = 0.006325 

a,b 

a 

b 

b 

b 

-1.7 

-1.2 

-0.7 

-0.2 

0.3 

0.8 

1.3 

1 2 3 4 5 

Channel depth in the meadow 

p = 0.001374 

a,b a 

c 

a,b,c 

b,c 

-1.7 

-1.2 

-0.7 

-0.2 

0.3 

0.8 

1.3 

1 2 3 4 5 

Knickpoint slope 

p = 1.9 * 10-6 

b 

a 

b 

b 

b 

-1.7 

-1.2 

-0.7 

-0.2 

0.3 

0.8 

1.3 

1 2 3 4 5 

Knickpoint height 

p = 0.188361 

-1.7 

-1.2 

-0.7 

-0.2 

0.3 

0.8 

1.3 

1 2 3 4 5 

Percent vertical bank 

p = 0.094375 

Standard scores Standard scores Standard scores 

Meadow Groups 

Meadow Groups 

Group 1 meadows tended to have fewer knickpoints than 

steep, low-discharge meadows. Knickpoint slopes were 

much steeper than the reach average slopes in this part of 

the system and, therefore, the disparity in stream power was 

much greater between the knickpoint and the surrounding 

channel gradients. This could cause knickpoint migration to 

occur more rapidly and, thus, fewer knickpoints to be observed. The difference in Group 1 knickpoints also could be 

related to differences in underlying sediment grain size.

Both depth of channel and percent of vertical bank generally increased with increasing discharge. As a result, 

Groups 1 and 2 had deeper channels and steeper banks than 

the other groups. Group 3 and 4 meadows had shallow channels with less steep banks. Group 5 meadows had mostly 

shallow channels, but a few exceptions skewed the average 

presented in fig. 7.5. The steepness of these meadows results 

in the potential for catastrophic incision.

There were significant differences in some of the vegetation communities across the meadow groups (ANOVA p 

values ranged from less than 0.00001 to 0.345; fig. 7.5). The 

strongest patterns occurred in the willow and wet meadow 

plant communities. Groups 1 and 2 had substantial willow 

communities, primarily along the channel, while Groups 3 

through 5 did not. The higher discharges that these meadows experienced during spring snowmelt were more likely 

to create the necessary conditions for willow establishment, 

including bare soils and inset terraces. Group 1 meadows 

had the most wet meadow community, while Group 5 meadows had very little of this plant community. This was likely 

the result of differences in groundwater discharge during the 

growing season. There were also significant differences in 

the dry meadow community across the meadow groups, but 

the pattern of the differences was similar to the pattern of 

meadow size across meadow groups. Since Group 1 meadows were bigger, they had more dry meadow community. A 

comparison of the percentage of the meadow complex that 

was dry meadow showed that there were no significant differences across groups (p = 0.067).

Figure 7.5. Mean and standard error for 

variables that are indicative of meadow 

degradation by meadow group. 

Standardized values were used in these 

figures. P values show differences among 

groups from one-way ANOVAs. Groups 

with unlike letters are significantly different 

(p<0.05).
106 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Management Summary

The results of this study indicate that the meadows in this 

region can be divided into groups based on their watershed 

size and elevation and their position in the watershed. These 

groups provide important information about what plant communities and channel shapes managers should expect to find 

and, thus, when active management is necessary to preserve 

meadow conditions (table 7.5). It is reasonable to expect that 

different groups will respond differently to stabilization efforts. In general, meadows that experience less discharge and 

that have lower slopes are likely to be the best candidates for 

stabilization. Stabilization of meadows with higher discharge 

and greater slopes requires a more detailed understanding of 

the meadow’s geomorphic and hydrologic controls.

Table 7.5 provides a summary of the groups, and table 7.2 

shows values for the watershed characteristics used to develop 

the groups. This information can be used by managers to make 

assessments of meadow conditions in the field. While it is not 

practical for managers to measure all of the variables used in 

this study, it is possible to quickly estimate many of the variables, such as relief and maximum elevation of the watershed 

and elevation and size of the meadow. This information can 

be used to determine the meadow group. Once the group is 

known, the meadow can be compared to other meadows with 

similar watershed characteristics to determine whether the 

channel is deeper than would be expected or if there is a larger 

Table 7.5. Meadow groups and summary of geomorphic and vegetation characteristics.

Watershed Meadow Groundwater Stream channel

Group characteristics characteristics Discharge influence characteristics Vegetation

1 Large, high Large watershed area High to High; many springs Deep channels, Wet, mesic, dry

elevation, high above meadow, moderate and seeps, restrictive high % vertical shrub and willow

precipitation large size, very low layers bank; few, small in similar

 meadow gradient knickpoints abundance

2 Intermediate Moderate watershed Moderate to Moderate; Variable, deeply Willow dominate

size and area above meadow, high intermediate springs; incised channels with lower amounts

elevation, moderate size and restrictive layers to many surface of wet, mesic,

moderate gradient channels; and dry shrub

precipitation knickpoints 

 intermediate

3 Small, low Low to moderate Low High; intermediate Minimal incision, Wet, mesic, and

elevation, high area above meadow, springs; strong, low channel dry shrub dominate

relief, small size, moderate restrictive layers depths; few

moderate gradient knickpoints

precipitation

4 Small, very Small area above Low High; few springs; Minimal incision, Dry shrub, mesic,

low elevation meadow, small to strong, restrictive low channel and wet dominate

and relief, high intermediate size, layers depths; few

precipitation high gradient knickpoints

5 Intermediate Very small area Very low Moderate, few Minimal incision, Mesic and dry

size and above meadow, very springs; restrictive low channel shrub dominate

elevation, low small size, very high layers depths; few with lesser amounts

precipitation gradient knickpoints of wet and dry

willow community or smaller wet meadow community than 

would be expected. This approach allows managers to compare different meadows both within and across groups and to 

prioritize management and restoration activities accordingly. 

For example, a Group 1 meadow with large knickpoints and a 

small wet meadow community would be a higher priority for 

stabilization than a Group 5 meadow with similar conditions.

Acknowledgments

We thank Danielle Johnson, Rita Dodge, Jacob Miller, 

Anne Farady, and Dave Board for their hard work in the 

field.

References

Allen-Diaz, B.H. 1991. Water-table and plant-species relationships 

in Sierra-Nevada meadows. American Midland Naturalist. 126: 

30-43.

Allen-Diaz, B.; Jackson, R.D.; Fehmi, J.S. 1998. Detecting channel 

morphology change in California’s hardwood rangeland spring 

ecosystems. Journal of Range Management. 51: 514-518.

Berlow, E.L.; D’Antonio, C.M.; Reynolds, S.A. 2002. Shrub 

expansion in montane meadows: the interaction of local-scale 

disturbance and site aridity. Ecological Applications. 12: 

1103-1118.

Beyer, H.L. 2004. Hawth’s analysis tools for ArcGIS. Available: 

http://www.spatialecology.com/htools.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 107

Brierley, G.J.; Fryirs, K. 2000. River styles, a geomorphic 

approach to catchment characterization: implications for river 

rehabilitation in Bega catchment, New South Wales, Australia. 

Environmental Management. 25: 661-679.

Castelli, R.M.; Chambers, J.C.; Tausch, R.J. 2000. Soil-plant 

relations along a soil-water gradient in great basin riparian 

meadows. Wetlands. 20: 251-266.

Chambers, J.C.; Linnerooth, A.R. 2001. Restoring riparian 

meadows currently dominated by Artemisia using alternative 

state concepts—the establishment component. Applied 

Vegetation Science. 4: 157-166.

Chambers, J.C.; Miller, J.R. 2004. Restoring and maintaining 

sustainable riparian ecosystems—the Great Basin Ecosystem 

Management Project. In: Chambers, J.C.; Miller, J.R., eds. 

Great Basin Riparian Ecosystems—Ecology, Management, and 

Restoration. Covelo, CA: Island Press: 1-24.

Chambers, J.C.; Miller, J.R.; Germanoski, D.; Weixelman, D.A. 

2004b. Process based approaches for managing and restoring 

riparian ecosystems. In: Chambers, J.C.; Miller, J.R., eds. 

Great Basin Riparian Ecosystems—Ecology, Management, and 

Restoration. Covelo, CA: Island Press: 261-292.

Chambers, J.C.; Tausch, R.J.; Korfmacher, J.L.; Miller, J.R.; Jewett, 

D.G. 2004a. Effects of geomorphic processes and hydrologic 

regimes on riparian vegetation. In: Chambers, J.C.; Miller, J.R., 

eds. Great Basin Riparian Ecosystems—Ecology, Management, 

and Restoration. Covelo, CA: Island Press: 196-231.

Coles-Ritchie, M.C.; Roberts, D.W.; Kershner, J.L.; Henderson, 

R.C. 2007. Use of a wetland index to evaluate changes in 

riparian vegetation after livestock exclusion. Journal of the 

American Water Resources Association. 43: 731-743.

Daly, C.; Taylor, G. 1998. Annual precipitation (PRISM) 1961-

1990. Water and Climate Center of the Natural Resources 

Conservation Service. Available: http://www.wcc.nrcs.usda.

gov/. [18 Jan 2011].

Darrouzet-Nardi, A.; D’Antonio, C.M.; Dawson, T.E. 2006. Depth 

of water acquisition by invading shrubs and resident herbs in a 

Sierra Nevada meadow. Plant and Soil. 285: 31-43.

Dobkin, D.S.; Rich, A.C.; Pyle, W.H. 1998. Habitat and avifaunal 

recovery from livestock grazing in a riparian meadow system 

of the northwestern Great Basin. Conservation Biology. 12: 

209-221.

Dwire, K.A.; Kauffman, J.B.; Baham, J.E. 2006. Plant species 

distribution in relation to water table depth and soil redox 

potential in Montane riparian meadows. Wetlands. 26: 131-146.

Fleischner, T.L. 1994. Ecological costs of livestock grazing in 

western North-America. Conservation Biology. 8: 629-644.

Germanoski, D.; Miller, J.R. 2004. Basin sensitivity to channel 

incision in response to natural and anthropogenic disturbance. 

In: Chambers, J.C.; Miller, J.R., eds. Great Basin Riparian 

Ecosystems—Ecology, Management, and Restoration. Covelo, 

CA: Island Press: 88-123.

Green, D.M.; Kauffman, J.B. 1995. Succession and livestock 

grazing in a northeastern Oregon riparian ecosystem. Journal of 

Range Management. 48: 307-313.

Groeneveld, D.P.; Or, D. 1994. Water-table induced shrubherbaceous ecotone-hydrologic management implications. 

Water Resources Bulletin. 30: 911-920.

Hess, G.W. 2002. Updated techniques for estimating monthly 

streamflow-duration characteristics at ungaged and partialrecord sites in central Nevada. Open-File Report 02-168. 

Carson City, NV: U.S. Geological Survey. 16 p.

Jackson, R.D.; Allen-Diaz, B. 2006. Spring-fed wetland and 

riparian plant communities respond differently to altered 

grazing intensity. Journal of Applied Ecology. 43: 485-498.

Jenson, S.E.; Platts, W.S. 1990. Restoration of degraded riverine/

riparian habitat in the Great Basin and Snake River regions. 

In: Kusler, J.A.; Kentula, M.E., eds. Wetland creation and 

restoration: the status of the science. Washington, DC: Island 

Press: 367-398.

Kauffman, J.B.; Thorpe, A.S.; Brookshire, E.N.J. 2004. Livestock 

exclusion and belowground ecosystem responses in riparian 

meadows of eastern Oregon. Ecological Applications. 14: 

1671-1679.

Kluse, J.S.; Allen-Diaz, B. 2005. Importance of soil moisture and 

its interaction with competition and clipping for two montane 

meadow grasses. Plant Ecology. 176: 87-99.

Loheide, S.P.; Gorelick, S.M. 2007. Riparian hydroecology: a 

coupled model of the observed interactions between groundwater 

flow and meadow vegetation patterning. Water Resources 

Research. 43, W07414, doi: 10.1029/2006WR005233.

Manning, M.E.; Padgett, W.G. 1995. Riparian community type 

classification for Humboldt and Toiyabe National Forests, 

Nevada and eastern California. R4-Ecol-95-01. Ogden, UT: 

U.S. Department of Agriculture, Forest Service, Intermountain 

Region.

Martin, D.W.; Chambers, J.C. 2001. Restoring degraded riparian 

meadows: biomass and species responses. Journal of Range 

Management. 54: 284-291.

McCune, B.; Mefford, M.J. 1999. Multivariate Analysis of 

Ecological Data Version 4.25. Gleneden Beach, OR: MjM 

Software.

Miller, J.; Germanoski, D.; Waltman, K.; Tausch, R.; Chambers, 

J. 2001. Influence of late Holocene hillslope processes and 

landforms on modern channel dynamics in upland watersheds 

of central Nevada. Geomorphology. 38: 373-391.

Miller, J.R.; House, K.; Germanoski, D.; Tausch, R.; Chambers, 

J.C. 2004. Fluvial geomorphic responses to Holocene climate 

change. In: Chambers, J.C.; Miller, J.R., eds. Great Basin 

Riparian Ecosystems—Ecology, Management, and Restoration. 

Covelo, CA: Island Press: 49-87.

Montgomery, D.R. 1999. Process domains and the river continuum. 

Journal of the American Water Resources Association. 35: 

397-410.

Naumburg, E.; Mata-Gonzalez, R.; Hunter, R.G.; Mclendon, T.; 

Martin, D.W. 2005. Phreatophytic vegetation and groundwater 

fluctuations: a review of current research and application of 

ecosystem response modeling with an emphasis on Great Basin 

vegetation. Environmental Management. 35: 726-740.

Sidle, R.C.; Sharma, A. 1996. Stream channel changes associated 

with mining and grazing in the Great Basin. Journal of 

Environmental Quality. 25: 1111-1121.

Trimble, S.W.; Mendel, A.C. 1995. The cow as a geomorphic 

agent—a critical review. Geomorphology. 13: 233-253.

U.S. Department of Agriculture, Natural Resources Conservation 

Service, National Weather and Climate Center [NWCC]. 

2007. Historical accumulated precipitation (daily) for site 337 

in the state of Nevada. Available: http://www.wcc.nrcs.usda.

gov/snotel/snotelday2.pl?site=337&station=17k04s&state=n 

&report=precip_accum_hist. [15 September 2007].

Weixelman, D.A.; Zamudio, D.C.; Zamudio, K.A. 1996. Central 

Nevada riparian field guide. R4-Ecol-96-01. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Intermountain 

Region.

Wright, J.M.; Chambers, J.C. 2002. Restoring riparian meadows 

currently dominated by Artemisa using alternative state 

concepts—above-ground vegetation response. Applied 

Vegetation Science. 5: 237-24
108 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Appendix 7.1. Meadow ecological types included in this study relative to those in prior studies by Manning and Padgett (1995) and Weixelman and 

others (1996).

Wet Mesic Dry

meadow meadow meadow Dry shrub Willow Rose

Manning Deschampsia Hordeum Carex douglasii, not described Salix exigua/Rosa Rosa woodsii, Artemisia

and caespitosa, brachyantherum, Iris missouriensis/ woodsii, Salix tridentata/Rosa woodsii

Padgett (1995) Carex nebrascensis, Juncus balticus, Dry graminoid exigua/Mesic forb,

Deschampsia Poa pratensis Salix exigua/Bench,

caespitosa/Carex Salix lutea/Rosa

nebrascensis, woodsii, Salix

Carex rostrata lutea/Mesic forb, 

 Salix lutea/Mesic 

 graminoid, Salix 

lutea/Poa pratensis, 

Salix lutea/Bench

Weixelman and Deschampsia Mesic graminoid Dry graminoid Artemisia Warm willow/Mesic not described

others (1996) caespitosa, Carex tridentata/ graminoid, Cold

nebrascensis Leymus willow/Mesic

 cinereus, graminoid, Warm

 Artemisia willow/Mesic forb,

 tridentata/ Cold willow/

Poa secunda Mesic forb
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 109

Appendix 7.2. Location and watershed characteristics of the 56 study meadows (ppt = precipitation).

UTM coordinates Watershed Average Total Channel Percent

(zone 11, NAD83) area ppt above meadow length of

 above above ppt above channel

Mountain meadow meadow (hectare meadow above

Study meadow range X Y (ha) (cm) meter) (km) meadow

Barley 1 Monitor 529,295 4,276,464 7314 35.0 2559 19.65 84%

Barley Tributary Monitor 526,723 4,274,294 378 27.9 105 3.73 76%

Big Creek Toiyabe 489,606 4,353,018 1181 47.3 558 6.42 54%

Birch 1 Toiyabe 496,430 4,361,054 3548 48.7 1729 9.21 64%

Birch 2 Toiyabe 495,667 4,361,054 1967 49.1 966 8.53 60%

Birch Tributary Toiyabe 495,974 4,363,926 293 48.3 141 2.61 23%

Cahill 2 Toiyabe 496,700 4,368,506 223 47.9 107 2.55 39%

Cahill 3 Toiyabe 496,069 4,368,479 143 47.7 68 2.04 31%

Cloverdale Toiyabe 456,953 4,283,689 2617 31.6 827 9.61 92%

Corcoran 1 Toquima 515,000 4,282,390 687 37.3 256 4.94 74%

Corcoran 2 Toquima 514,653 4,282,279 649 37.5 244 4.51 67%

Corcoran 3 Toquima 514,007 4,282,497 498 38.9 194 3.86 57%

Corcoran 4 Toquima 513,540 4,282,488 438 39.4 173 3.30 49%

Corcoran 5 Toquima 513,193 4,282,706 200 41.4 83 3.03 45%

Corcoran main 1 Toquima 513,861 4,283,505 648 42.5 276 4.84 56%

Corcoran main 2 Toquima 513,635 4,283,634 583 43.1 251 4.38 51%

Corcoran main 3 Toquima 513,510 4,283,780 574 43.1 247 4.15 48%

Corral 1 Toquima 516,350 4,330,167 1482 46.6 691 5.79 76%

Corral 2 Toquima 514,558 4,331,776 738 45.3 334 3.20 42%

Cottonwood Toiyabe 476,261 4,333,290 1859 47.1 877 8.16 87%

Danville Monitor 541,631 4,291,374 1654 36.3 600 6.89 83%

East Dobbin Monitor 542,226 4,309,058 124 33.0 41 1.45 29%

Emigrant 1 Toiyabe 497,845 4,374,140 346 43.7 151 2.87 56%

Emigrant 2 Toiyabe 497,728 4,373,870 171 43.2 74 2.42 47%

Fandango 1 Hot Creek 557,140 4,279,305 131 30.5 40 1.67 16%

Fandango 2 Hot Creek 557,029 4,279,484 104 30.5 32 1.45 14%

Green Monster Monitor 540,510 4,288,100 862 35.3 304 4.81 55%

Indian Valley Toiyabe 456,553 4,294,540 4195 32.8 1376 10.79 55%

Johnson 1 Toiyabe 491,499 4,364,700 320 45.5 146 2.97 77%

Johnson 2 Toiyabe 491,651 4,364,427 70 43.5 31 2.22 70%

Johnson 3 Toiyabe 491,775 4,364,160 61 43.6 27 2.01 64%

Kingston 0 Toiyabe 486,048 4,343,055 4146 49.7 2061 11.86 64%

Kingston 1 Toiyabe 485,696 4,344,852 2809 50.2 1412 9.49 51%

Kingston 3 Toiyabe 486,351 4,346,888 1885 49.5 933 6.91 37%

Lebeau Shoshone 447,400 4,326,498 981 27.7 272 6.65 98%

Little Cow Hot Creek 558,062 4,280,032 10 33.0 3 0.65 4%

Meadow 1 Toquima 506,930 4,282,767 327 38.9 127 2.46 22%

Meadow 2 Toquima 506,544 4,282,941 303 39.0 118 2.02 18%

Mohawk Toiyabe 468,626 4,316,169 963 36.9 355 7.09 94%

Mosquito Monitor 526,990 4,296,652 9503 38.0 3611 18.24 99%

Round Mountain Toquima 509,254 4,281,450 501 40.7 204 3.34 36%

San Juan 1 Toiyabe 476,380 4,330,043 2296 40.2 922 6.52 63%

San Juan 2 Toiyabe 476,925 4,329,976 1077 43.0 463 5.86 57%

Six Mile 1 Hot Creek 560,532 4,281,282 361 32.8 118 2.50 18%

Six Mile 2 Hot Creek 560,435 4,281,069 289 33.0 95 2.29 17%

South Crane Toiyabe 469,284 4,312,691 749 44.0 329 4.63 76%

Stargo Monitor 543,507 4,311,320 33 33.0 11 0.71 14%

Wadsworth 1 Monitor 536,298 4,301,974 446 41.5 185 3.72 40%

Wadsworth 2 Monitor 536,347 4,301,500 41 43.2 18 2.20 25%

Wadsworth 3 Monitor 536,539 4,301,924 148 41.4 61 3.04 33%

Wadsworth 4 Monitor 537,125 4,301,385 126 42.0 53 2.25 24%

Washington Toiyabe 477,281 4,334,192 1885 49.8 940 9.23 89%

West Dobbin Monitor 541,312 4,311,707 46 33.0 15 0.98 10%

West 

Northumberland Toquima 509,818 4,315,357 962 42.6 410 5.03 46%

Willow Monitor 543,653 4,318,379 598 33.0 198 4.35 61%

Red Canyon Roberts 550,627 4,415,250 529 36.0 190 4.23 82%
110 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Appendix 7.3. Watershed and meadow geomorphic characteristics of the 56 study meadows.

 Max Area Length

Meadow Area above watershed Max Shape whole whole Slope Meadow 

elevation 2743 m elevation relief whole watershed watershed within size

Study meadow (m) (ha) (m) (m) watershed (ha) (m) meadow (ha)

Barley 1 2267 2978 3235 968 6.29 8645 23,320 1.4% 2.05

Barley Tributary 2271 0 2780 509 5.24 459 4907 6.7% 1.17

Big Creek 2168 403 3370 1202 4.16 3384 11,872 5.4% 0.64

Birch 1 2153 272 3287 1134 4.32 4722 14,284 2.1% 8.22

Birch 2 2179 245 3287 1108 4.32 4722 14,284 1.6% 9.32

Birch Tributary 2316 0 2749 433 2.06 4722 11,138 7.8% 1.72

Cahill 2 2304 0 2527 223 4.64 412 6537 2.5% 2.19

Cahill 3 2329 0 2527 198 4.64 412 6537 4.7% 3.15

Cloverdale 2157 41 2929 772 4.04 14,153 10,439 1.8% 4.45

Corcoran 1 2277 32 2974 697 3.84 695 6716 4.5% 1.14

Corcoran 2 2289 32 2974 685 3.84 695 6716 2.9% 0.81

Corcoran 3 2328 32 2974 645 3.84 695 6716 5.7% 1.94

Corcoran 4 2349 32 2974 625 3.84 695 6716 3.9% 1.68

Corcoran 5 2359 32 2974 614 3.84 695 6716 6.8% 1.52

Corcoran main 1 2365 41 2969 604 5.75 892 8671 3.9% 0.77

Corcoran main 2 2392 41 2969 577 5.75 892 8671 3.9% 1.31

Corcoran main 3 2403 41 2969 566 5.75 892 8671 5.2% 1.35

Corral 1 2373 0 2705 332 3.23 1786 7593 2.4% 2.25

Corral 2 2459 0 2705 245 3.23 1786 7593 4.0% 3.01

Cottonwood 2142 629 3343 1201 4.27 2045 9366 3.6% 1.36

Danville 2275 541 3301 1026 4.03 1694 8261 2.9% 4.46

East Dobbin 2537 15 2915 378 4.07 629 5062 13.7% 0.54

Emigrant 1 2094 0 2387 293 3.94 674 5153 2.0% 3.00

Emigrant 2 2108 0 2387 279 3.94 674 5153 3.0% 1.83

Fandango 1 2611 61 2928 317 10.11 1085 10,471 6.6% 0.88

Fandango 2 2631 53 2928 297 10.11 1085 10,471 6.8% 0.76

Green Monster 2342 377 3212 870 5.52 1386 8747 6.6% 4.27

Indian Valley 2244 249 2929 685 4.61 8485 19,786 0.4% 15.59

Johnson 1 2023 0 2648 624 3.22 459 3847 10.0% 4.46

Johnson 2 2098 0 2646 548 3.22 459 3166 15.6% 0.98

Johnson 3 2119 0 2646 527 3.22 459 3166 18.1% 1.86

Kingston 0 2239 1143 3489 1250 5.39 6361 18,524 0.2% 7.21

Kingston 1 2275 968 3489 1214 5.39 6361 18,524 0.9% 2.82

Kingston 3 2320 649 3463 1142 5.39 6361 18,524 1.4% 5.16

Lebeau 2134 82 3064 930 4.71 981 6799 6.2% 6.44

Little Cow 2611 2 2877 266 10.47 2544 16,317 10.6% 3.78

Meadow 1 2446 6 2786 340 1.82 6970 11,277 4.1% 3.92

Meadow 2 2473 6 2747 274 1.82 6970 11,277 5.1% 5.89

Mohawk 2259 418 3203 944 5.89 975 7579 3.5% 4.61

Mosquito 2129 4340 3321 1192 3.57 9509 18,418 2.2% 4.10

Round Mountain 2402 49 2972 570 3.03 6970 9304 4.4% 4.06

San Juan 1 2227 466 3110 884 3.82 2776 10,300 3.4% 3.67

San Juan 2 2254 367 3110 856 3.82 2776 10,300 4.3% 0.99

Six Mile 1 2530 141 2992 462 13.32 1427 13,788 4.0% 0.72

Six Mile 2 2545 110 2992 448 13.32 1427 13,788 4.8% 0.78

South Crane 2376 444 3261 886 3.99 922 6063 5.9% 1.21

Stargo 2585 0 2713 128 5.02 515 5081 6.4% 1.70

Wadsworth 1 2507 206 3189 682 4.74 1822 9294 3.6% 9.64

Wadsworth 2 2557 24 3032 475 4.15 1822 8696 11.5% 1.04

Wadsworth 3 2534 101 3189 655 4.15 1822 9294 7.3% 2.07

Wadsworth 4 2589 101 3189 600 4.15 1822 9294 10.1% 1.32

Washington 2178 698 3380 1202 5.46 2066 10,360 5.1% 1.98

West Dobbin 2464 0 2648 184 4.59 1990 9559 5.5% 2.58

West 

Northumberland 2192 12 2796 604 2.86 4185 10,931 5.7% 3.29

Willow 2403 83 2974 571 2.55 1994 7130 5.2% 1.25

Red Canyon 2024 0 2275 251 4.03 663 5171 2.8% 1.58
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 111

Appendix 7.4. Channel characteristics and number of springs of the 56 study meadows.

 Channel

Sinuosity length in Channel Number Knickpoint Percent Number 

in meadow depth of height Knickpoint vertical of 

Study meadow meadow (m) (m) knickpoints (m) slope bank springs

Barley 1 1.16 243 2.05 3 0.54 9% 39% 11

Barley Tributary 1.09 136 0.00 5 0.93 19% 0% 14

Big Creek 1.13 89 0.79 2 0.53 10% 75% 3

Birch 1 1.18 602 1.20 2 0.49 10% 56% 11

Birch 2 1.25 762 1.38 3 0.82 8% 67% 20

Birch Tributary 1.12 215 1.07 6 0.82 23% 22% 1

Cahill 2 1.07 370 0.43 5 0.70 28% 41% 0

Cahill 3 1.04 562 0.51 4 0.98 15% 36% 5

Cloverdale 1.03 451 0.19 3 0.65 14% 0% 2

Corcoran 1 1.05 266 0.00 4 1.26 13% 0% 0

Corcoran 2 1.06 136 0.00 3 0.86 24% 0% 0

Corcoran 3 1.07 263 0.12 3 1.29 15% 0% 0

Corcoran 4 1.14 168 0.26 2 0.71 13% 59% 0

Corcoran 5 1.12 360 0.00 6 0.29 25% 0% 0

Corcoran main 1 1.09 178 1.27 2 0.18 9% 56% 0

Corcoran main 2 1.07 129 1.10 2 0.82 14% 69% 5

Corcoran main 3 1.08 110 1.83 2 0.74 17% 51% 12

Corral 1 1.16 361 0.38 4 1.03 18% 8% 8

Corral 2 1.03 131 0.00 1 1.04 34% 0% 2

Cottonwood 1.09 188 1.95 4 1.02 16% 100% 1

Danville 1.12 204 1.29 81% 7

East Dobbin 1.10 80 2.13 6 1.56 32% 0% 12

Emigrant 1 1.01 370 0.40 4 0.44 24% 21% 0

Emigrant 2 1.07 149 0.72 6 0.32 14% 18% 1

Fandango 1 1.09 98 1.66 2 0.64 16% 22% 3

Fandango 2 1.08 143 1.24 6 0.50 24% 53% 2

Green Monster 1.17 228 1.11 5 0.66 28% 52% 13

Indian Valley 1.50 1093 0.51 2 1.57 11% 0% 0

Johnson 1 1.08 544 0.00 2 1.39 30% 0% 9

Johnson 2 1.06 201 0.00 2 1.00 49% 0% 5

Johnson 3 1.09 313 0.86 11 1.33 39% 17% 5

Kingston 0 1.60 732 0.97 0 0.00 0% 94% 18

Kingston 1 1.54 527 1.05 0 0.00 0% 0% 3

Kingston 3 1.19 373 1.54 0 0.00 0% 45% 17

Lebeau 1.09 806 0.75 9 1.00 19% 21% 5

Little Cow 1.05 190 0.00 5 0.97 26% 0% 2

Meadow 1 1.17 275 0.43 5 0.33 17% 40% 7

Meadow 2 1.12 475 0.87 7 0.51 15% 84% 9

Mohawk 1.07 94 0.52 6 0.69 12% 0% 0

Mosquito 1.08 192 1.22 3 0.26 9% 95% 0

Round Mountain 1.05 229 0.38 7 0.52 18% 0% 8

San Juan 1 1.20 555 1.65 4 0.55 7% 44% 6

San Juan 2 1.06 86 1.94 3 0.65 18% 48% 4

Six Mile 1 1.11 105 2.41 2 0.19 23% 15% 2

Six Mile 2 1.08 106 1.06 3 0.54 15% 41% 2

South Crane 1.09 98 2.04 2 0.40 13% 22% 3

Stargo 1.08 311 0.86 10 1.05 15% 24% 0

Wadsworth 1 1.16 677 1.54 5 1.08 24% 19% 12

Wadsworth 2 1.05 296 0.00 4 0.58 24% 0% 6

Wadsworth 3 1.12 230 2.61 7 0.41 15% 55% 4

Wadsworth 4 1.10 285 1.59 3 1.49 23% 92% 7

Washington 1.01 125 1.73 1 0.88 18% 100% 8

West Dobbin 1.03 216 0.00 3 0.26 17% 0% 0

West 

Northumberland 1.05 111 0.00 5 1.96 14% 0% 13

Willow 1.10 230 1.25 3 0.55 24% 0% 7

Red Canyon 1.04 218 0.00 5 0.44 11% 0% 0
112 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

Appendix 7.5. The percentage of eight vegetation types within the 56 study meadows.

Vegetation type

 Mesic Dry

Wet Mesic shrub Dry shrub

Willow meadow meadow meadow meadow meadow Aspen Rose

Study meadow (%) (%) (%) (%) (%) (%) (%) (%)

Barley 1 41 13 0 36 0 10 0 0

Barley Tributary 7 28 10 7 15 33 0 0

Big Creek 49 10 9 0 0 32 0 0

Birch 1 4 50 18 0 16 13 0 0

Birch 2 25 11 33 0 14 10 7 0

Birch Tributary 1 25 18 0 0 0 45 11

Cahill 2 0 24 24 0 14 38 0 0

Cahill 3 0 10 6 0 35 33 15 0

Cloverdale 51 20 21 0 0 8 0 0

Corcoran 1 0 47 45 0 0 8 0 0

Corcoran 2 0 72 23 0 0 5 0 0

Corcoran 3 14 26 34 20 0 5 0 0

Corcoran 4 3 8 23 0 13 53 0 0

Corcoran 5 16 59 0 0 0 25 0 0

Corcoran main 1 0 18 33 0 0 49 0 0

Corcoran main 2 6 21 16 0 0 57 0 0

Corcoran main 3 0 27 15 0 0 58 0 0

Corral 1 0 34 22 7 0 36 0 0

Corral 2 0 10 8 0 14 68 0 0

Cottonwood 10 0 28 0 8 7 47 0

Danville 61 0 3 0 3 33 0 0

East Dobbin 0 14 41 0 0 45 0 0

Emigrant 1 0 0 31 0 22 47 0 0

Emigrant 2 0 0 15 0 36 49 0 0

Fandango 1 0 0 86 0 0 14 0 0

Fandango 2 0 0 39 0 0 61 0 0

Green Monster 46 14 11 11 0 18 0 0

Indian Valley 0 2 40 0 40 19 0 0

Johnson 1 2 60 12 0 0 25 0 0

Johnson 2 13 44 9 0 0 18 0 16

Johnson 3 0 29 15 2 0 11 20 22

Kingston 0 12 18 32 0 5 7 24 2

Kingston 1 58 8 11 0 6 17 0 0

Kingston 3 2 24 25 0 12 38 0 0

Lebeau 9 30 32 0 13 15 0 0

Little Cow 0 4 37 59 0 0 0 0

Meadow 1 0 29 27 0 0 43 0 0

Meadow 2 0 11 54 12 15 9 0 0

Mohawk 88 8 2 0 0 2 0 0

Mosquito 51 7 8 24 5 5 0 0

Round Mountain 0 4 51 0 3 42 0 0

San Juan 1 42 2 14 0 0 12 23 9

San Juan 2 52 1 18 0 0 29 0 0

Six Mile 1 0 0 38 2 11 49 0 0

Six Mile 2 0 21 29 0 0 49 0 0

South Crane 78 0 1 4 0 17 0 0

Stargo 0 0 35 31 0 34 0 0

Wadsworth 1 0 27 25 0 31 17 0 0

Wadsworth 2 2 61 7 0 1 29 0 0

Wadsworth 3 0 2 25 0 44 29 0 0

Wadsworth 4 1 9 26 0 20 44 0 0

Washington 49 12 3 0 10 0 11 16

West Dobbin 0 0 50 0 3 47 0 0

West 

Northumberland 1 15 12 0 0 55 0 17

Willow 16 26 24 0 0 11 0 23

Red Canyon 0 0 76 0 0 24 0 0
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 113

Introduction

Restoration and management objectives and approaches are most effective when based on an understanding of 

ecosystem processes and the long- and short-term causes of 

disturbance (Wohl and others 2005). As detailed in previous 

chapters, several factors are critical in developing effective management strategies for streams and their associated 

meadow ecosystems in the central Great Basin. First, many 

streams and/or valley floors are still responding to a major 

drought that occurred almost 2000 years BP that stripped 

the hillslopes of available sediment and resulted in a natural tendency toward incision. Second, human disturbance 

has increased both the rate and magnitude of this incision. 

Since settlement of the Great Basin region in 1860, upland 

watersheds have undergone significant changes in land use, 

vegetation cover, and climate that have altered the hydrologic and sedimentologic regimes of the axial drainage system 

and its associated meadows. Many meadow complexes are 

at increased risk of incision because they often are located 

on valley floors with stepped profiles caused by side-valley 

alluvial fans in the longitudinal profile. While some of the 

stream systems and their associated meadow complexes 

have adjusted to the current hydrologic and sedimentologic 

regimes and are now in a quasi-equilibrium state, others 

are in a nonequilibrium state and are still actively incising. 

Consequently, return to pre-incision conditions is an unrealistic goal for these dynamic systems.

Chambers and others (2004a) defined the goal of restoration and management activities as re-establishing and 

maintaining sustainable fluvial systems and riparian ecosystems that exhibit both characteristic processes and related 

biological, chemical, and physical linkages among system 

components (modified from Natural Research Council 

2002). In this context, sustainable stream systems and 

meadow complexes exhibit natural variability yet maintain 

characteristic processes, including rates and magnitudes of 

geomorphic activity, hydrologic flux and storage, biogeochemical cycling and storage, and biological activity and 

production (Christensen and others 1996; Wohl and others 

2005). Management objectives and approaches for central 

Great Basin meadow complexes must acknowledge the dynamic character of these ecosystems and focus on the current 

potential to support a given set of geomorphic, hydrological, 

and ecological conditions over a reasonable period of time 

(Chambers and others 2004a). The primary management 

objective should be to maintain and enhance meadow complexes by preventing further incision and avulsion where 

possible and by improving ecological conditions.

The characterization of meadow complexes in the central 

Great Basin (Chapter 7) and discussion of basin sensitivity to disturbance (Chapter 5) illustrate that not all systems 

have responded similarly to natural and anthropogenic disturbance. Meadow ecosystems exhibit varying degrees of 

stream incision, groundwater lowering, and riparian vegetation degradation based on their geomorphic and hydrologic 

controls and disturbance history. Management plans must 

be based on careful assessment both of the dominant geomorphic and hydrologic controls and of the causes of 

disturbance at watershed, valley segment, and site scales. 

These plans also must consider the current magnitude of 

incision or degradation and the potential for stream stabilization and vegetation management. Important elements of 

meadow management are prioritizing which meadows to 

treat, establishing objectives on a meadow-by-meadow basis, identifying and selecting treatment options, evaluating 

success through monitoring, and using the results for adaptive management. Each of these tasks is briefly discussed 

below.

Prioritizing Meadow Management

This report provides insights into the geomorphic, hydrologic, and biological processes that function within meadow 

complexes in the central Great Basin. These include: (1) a 

basic understanding of the potential for future meadow degradation; (2) a description of the processes by which the 

meadows are degraded; and (3) a means of assessing the 

likelihood of success for various treatment options. At larger 

scales, stream incision and its effects on meadow ecosystems are influenced by their position in the watershed, the 

magnitude and rate of runoff, the geomorphic and hydrologic sensitivity of the meadow, and the linkages between 

the groundwater system and the stream channel. Chapter 7 

provides a categorization of central Great Basin watersheds based on data collected from 56 meadows in upland 

watersheds in 2005 and 2006. A summary of the variables 

and methods of measurement are in table 7.1. The different meadow groups and their general characteristics are in 

table 7.5, and the averages for the most influential variables are in table 7.2. This information is a useful starting 

point for assessing current meadow conditions and the potential for future degradation. A metadata file and the data 

files for each meadow have been archived through the 

USDA Forest Service, Rocky Mountain Research Station 

and are available at: http://www.fs.fed.us/rm/data_archive/

dataaccess/Central_NV_Meadow_Characterization.shtml. 

Chapter 8: Meadow Management and 

Treatment Options

Jeanne C. Chambers and Jerry R. Miller
114 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

The files also can be accessed by following the links provided in the data archive: http://www.fs.fed.us/rm/data_archive. 

The central Nevada meadow characterization can be accessed 

by following the Data Access link. Prior to using these data, 

one must verify that the longitudinal and cross-sectional 

profiles and meadow characterizations are accurate because 

intervening high flows may result in knickpoint migration 

and other types of incision or avulsion. Also, inappropriate 

livestock use can influence meadow species composition.

Determining the likelihood of future meadow degradation and the potential for recovery requires an understanding 

of the geomorphic and hydrologic sensitivity of the meadows. The framework for understanding meadow sensitivity 

to disturbance is provided in Chapters 3 and 4, and its use 

is discussed in Chapter 5. Specifically, a set of factors is 

presented that can be used to determine the likelihood for 

geomorphic change and the probability that these alterations will result in significant declines in groundwater levels 

and, thus, changes in vegetation. Analysis of the sensitivity of individual meadows requires examining the factors 

discussed in table 5.1. This can be accomplished by using 

cartographic and remotely sensed data and by making field 

visits. Because meadow complexes are groundwater features 

that may or may not be closely tied to the surface channel 

system within the meadow complex, determining the linkages between the channel and groundwater flow system is of 

utmost importance in assessing the effect of channel incision 

on groundwater levels and vegetation types and distribution. 

A means of assessing surface water and groundwater interactions is described in Chapter 4 and examples are provided 

in table 4.2. This approach generally provides enough information to determine if major groundwater responses to 

incision (as well as various treatments) are likely.

Objectives and Design Criteria for 

Stream Stabilization and Meadow 

Vegetation Management

An understanding of the geomorphic, hydrologic, and biological processes within the meadows can be used to define 

a set of realistic management objectives for a given meadow. 

Developing these objectives is required to determine what 

constitutes project success, and it should be accomplished 

before any stream stabilization or vegetation management 

project is initiated. One must also formulate design or success criteria. Design (success) criteria are quantifiable 

benchmarks that specify how the various components of 

the work should perform and are used to ensure that the objectives of the project are met. Design criteria may include 

measurable limits to headcut or knickpoint advancement, 

bank stability, flood conveyance, and/or the aerial extent 

of specific meadow vegetation types (Skidmore and others 2001). Project success often depends on the effort that 

goes into developing design criteria because they are a guide 

to what needs to be accomplished for each component of 

the project (Miller and Orbock Miller 2007). Moreover, the 

process of constructing design criteria is likely to provide 

important insights into whether a particular objective can be 

achieved given the biophysical processes operating at the 

site.

Identification and Selection of 

Treatment Options

Establishing a General Framework

In recent years, managers have increasingly relied on 

channel evolution models (CEM) (Schumm and others 

1984; Simon and Hupp 1986; Simon 1989; Rosgen 1996, 

2001, 2006) to evaluate the magnitude of incision and the 

evolutionary changes in channel morphology during the entrenchment process and to identify potential management 

options. These models, which portray a semi-systematic series of geomorphic events once incision has begun, are not 

always applicable to upland drainages in the central Great 

Basin. In these drainages, incision is often characterized by 

episodes of avulsion and/or cyclical periods of gully erosion 

and deposition. For management purposes, it is useful to 

first classify the drainages according to their morphologic 

characteristics and dominate erosional and depositional processes. A simplistic approach to classification is to separate 

basins into two groups: those that exhibit riparian corridors 

that possess a discontinuous drainage system and those that 

possess an integrated drainage network. In the former, the 

valley floor is usually characterized by short reaches of 

stream channel (tens to a few hundred meters) that are incised into the valley fill, separated by unincised reaches that 

are devoid of a recognizable channel system (fig. 8.1). The 

dominant processes that are operating in these areas (such 

as in Indian Valley) are gully development and headcut advancement (Chapter 3). In the latter, the riparian corridor 

contains a continuous channel network throughout the basin, 

although flow within the channel may be locally ephemeral, 

particularly during the late summer months. The integrated 

drainages may be further subdivided into those exhibiting 

(1) low to moderate depths of incision (zero to two times 

bankfull channel depths), (2) highly incised channels (more 

than two times bankfull channel depths), and (3) “fully” incised channels that are currently in a state of equilibrium. 

The separation of these channels on the basis of incision is 

arbitrary, but it provides a useful system to discuss potential 

management options that can be applied to maintain and/or 

improve meadow ecosystems.

Low to Moderately Incised Channels. If the stream 

exhibits a limited degree of incision, it may be possible to 

use in-stream structures and bank stabilization measures to 

stabilize the stream channel. Channels with minor incision 

occur within all meadow groups but are most common in 

the smaller stream channels that occur in meadow Groups 

3, 4, and 5 (Chapter 7). Stabilizing channels and knickpoints 

when they first appear can prevent knickpoint migration and 

can minimize the effects of other factors that contribute to 

stream incision during episodic high flows. Channel stabilization is often sufficient to maintain meadow vegetation.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 115

Highly Incised Channels. Highly incised channels are 

found in all meadow groups but are most pronounced in 

Groups 1 and 2 (Chapter 7). Stream stabilization measures 

are possible but must be based on careful assessment of 

(1) the geomorphic and hydrologic sensitivity both within 

and upstream of the meadow and of (2) the linkages between 

the groundwater system and stream channel. Structures 

should be designed to accommodate geomorphic irregularities, like side-valley alluvial fans, episodic high flows, and 

the predominantly high gradients that occur in these systems. 

The primary objective of installing in-stream structures is to 

prevent or minimize further incision of the main channel, 

prevent incision of spring channels, and maintain existing 

springs and seeps. In some cases, it may be possible to stabilize the stream banks with plugs or transplants of meadow 

vegetation. The net effect of stabilizing stream channels can 

be to maintain or improve existing meadow vegetation if a 

progressive decrease in water tables can be halted. Once incision has been stopped, active vegetation management can 

be used to improve ecological conditions.

Fully Incised Channels. In cases where stream channels are fully incised and are now in a state of equilibrium, 

as sometimes occurs in Group 1 and 2 meadows (Chapter 

7), the stream channel typically has reached a stable configuration, although minor adjustments may occur as the 

stream works to expand its floodplain. It is seldom ecologically or economically feasible to reconstruct or elevate these 

streams. If groundwater tables have dropped, as indicated 

by shrub encroachment and drier vegetation types, it may 

be possible to actively manage the area to maintain meadow 

vegetation based on understanding the relationships between 

groundwater tables and riparian vegetation, as described below. It may not be possible to return these areas to the large, 

meadow complexes they once supported but, if water tables 

are sufficiently high, active vegetation management can be 

used to maintain them as smaller meadow complexes or dry 

meadows. Maintaining meadow vegetation within riparian 

corridors allows a mosaic of shrub- or tree-dominated areas 

and meadow complexes that more closely resembles predisturbance conditions and that provides important wildlife 

habitat.

General Considerations for 

Stream Stabilization

The approaches used for stabilizing minimally incised 

and highly incised streams must be aligned with the dominant mechanisms of incision. These mechanisms can vary 

among meadows, or even among areas within a given meadow. In some cases, incision may involve the grain-by-grain 

entrainment of channel bed sediment; in other instances, incision may be related to upstream migration of knickpoints 

generated by a lowering of the base level. Incision also may 

occur by means of groundwater sapping and headcut retreat. 

Areas affected by these different incision processes require 

their own set of objectives, design criteria, and treatment 

strategies.

While incision is likely to be the predominant problem 

of concern, it also is important to recognize that meadow 

Figure 8.1. Schematic diagram of discontinuous (top) and continuous (bottom) drainage basins. Continuous drainages 

are thought to have had an integrated, axial drainage network throughout the late Holocene.
116 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

complexes are groundwater features, and other geomorphic 

and hydrologic processes that operate in these environments 

must be considered in project design. The most important of 

those processes are: avulsion, breaching of confining units, 

and erosion by groundwater processes.

Avulsion

Although a stream may be incised, the instantaneous influx of coarse sediment to the meadow from upstream areas 

may lead to channel avulsion and entrenchment of a new 

stream segment in a completely different part of the meadow 

complex. In-stream structures and changes in riparian vegetation alter flow resistance and transport processes and may 

increase the potential for channel aggradation and avulsion. 

Thus, the sensitivity of the meadow to avulsion processes 

should be considered at every site where biophysical treatments are applied.

Breaching of Confining Units

Hydrologic data from instrumented meadows demonstrate that fine-grained (silt and clay-rich), confining 

units are an essential component of meadow development. 

Breaching of these units has the potential to result in major 

changes in the subsurface flow system and drainage of the 

meadow complex. Thus, management strategies must consider how any treatment will affect surface and subsurface 

flow systems and their interactions. Approaches like channel 

reconstruction or plug and pond methods that require excavation of alluvial materials are probably not appropriate for 

most central Nevada meadow systems and should be applied 

with extreme care.

Erosion by Groundwater Processes

Groundwater sapping (seepage erosion) has been observed to dramatically affect the riparian corridor of these 

upland catchments where there is ample water and the alluvial valley fill is composed of highly permeable sand or 

grus-sized sediment. Even minor modifications to these systems may lead to unexpected, deleterious consequences such 

as formation of deep gullies.

In-Stream Structures and Aquatic 

Habitat Enhancement Devices

In-stream structures and other aquatic enhancement devices were initially used at least a century ago to improve 

fish habitat in the United States (Beschta and others 1992; 

Thompson 2005). Since then, Federal agencies have relied 

heavily on the use of these structures to improve aquatic and 

riparian habitat (Frissell and Nawa 1992; Thompson 2005).

These devices fall into four broad categories (which are 

not mutually exclusive): grade control devices, habitat cover 

structures, bank protection devices, and flow deflectors or 

concentrators (Miller and Kochel 2008, 2010). Grade control 

structures are perhaps the most widely used and are intended 

to maintain the bed of the channel at its present elevation. 

These devices are typically composed of logs or large boulders and are installed within the channel in such a way as to 

inhibit channel bed erosion. Historically, these structures included various types of dams and/or weirs, including check 

dams, K-dams, jack dams, wedge dams, log or rock sills, 

and log drop structures (Seehorn 1992). Cover structures 

are intended to provide or improve aquatic habitat, particularly for fish. They include a wide range of devices, the most 

common of which are bank lunkers or cribs, raft and boom 

covers, log-and-brush shelters, and felled trees. Bank protection devices are designed to reduce the magnitude and rate 

of bank erosion. Until recently, these devices lined part or all 

channel margins with some form of erosionally resistant material and include A-Jacks, dirt or rock filled gabions, rock or 

crib walls, and rip-rap and stone toe revetments. Most flow 

deflection devices protrude out from the stream bank and are 

intended to narrow the channel, protect banks from erosion, 

or create pools (and pool habitats) through redirection and 

concentration of flow. The most common types are single 

or double wing deflectors and spurs. Flow deflectors also 

include various types of boulder placements, a practice that 

involves placing large boulders along the banks or within the 

channel to create localized zones of scour.

Since the early 1990s, there has been an attempt to restore or rehabilitate at least part of the structure, function, 

and diversity of the historic river (Riley 1998). Many projects use extensively hardened habitat improvement devices, 

including a new generation of rock or log structures that 

are endorsed by Rosgen and his colleagues (Rosgen 2001, 

2006), including cross-vanes, J-hooks, rock (or single arm) 

vanes, and W-weirs. These newly designed in-stream structures are intended to decrease near-bank velocities and shear 

stress by redirecting flow away from banks. Thus, their purpose is to reduce bank erosion and improve aquatic habitat 

by creating localized zones of channel bed scour and pool 

formation.

The uses, design, and installation of older habitat improvement devices, which are used extensively, have been 

thoroughly described in a number of manuals, including 

Arthur (1936), USDA Forest Service (1952), and Seehorn 

(1985, 1992). Use and design of more recently developed 

in-stream rock and log structures are described in Rosgen 

(2001, 2006). These manuals should be consulted to gain 

additional information on these structures.

Use of In-Stream Structures

A review of the past performance of in-stream and other 

improvement structures, combined with an understanding 

of erosion processes in Great Basin meadows, indicates that 

stream stabilization methods must be tailored to the specific characteristics of the system. As indicated in previous 

chapters, meadows often are located upstream of side-valley 

fans and are characterized by convexities in long channel/

valley profiles. Where this occurs, installing grade control 

structures at the toe of the fan may effectively stabilize the 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 117

channel. These stream reaches are important local, baselevel controls that dictate the magnitude of upstream incision. Inhibiting incision at the toe of the fan, which is 

generally co-located with a convexity in the longitudinal 

profile, will limit the amount of future erosion that can occur within the meadow. Erosion around these structures is 

more difficult as erosion in these reaches often requires the 

removal of bedrock or coarse-grained colluvial and alluvial 

fan sediments (fig. 8.2).

The use of in-stream structures and other devices throughout the meadow and upstream of side-valley fans should 

be used with more caution, particularly where there is evidence of past channel avulsions. Although structures such as 

rock vortex weirs and cross-vanes are intended to maintain 

sediment transport through the reach (Rosgen 2001), postproject evaluations in numerous regions of North America 

(such as British Columbia, California, and North Carolina) 

have shown that these structures often lead to in-channel 

deposition (Miller and Kochel 2008, 2010). Along meadow 

reaches where avulsions occur frequently, use of such structures may lead to channel deposition and flood flows over 

the meadow surface. This may cause subsequent incision 

or new channel formation and meadow degradation along a 

new part of the valley floor.

It also is important to recognize that post-project evaluations have shown that performance of in-stream structures 

and other habitat improvement devices varies dramatically 

from site to site (Miller and Kochel 2008, 2010). Variations 

in performance appear to be partially related to stream 

channel dynamics. Effectiveness is greatly reduced along 

channels that are characterized by high stream power, large 

sediment supplies, and erodible banks (fig. 8.3; Miller and 

Kochel 2008, 2010). Performance also tends to be much 

lower along unstable channels that experience changes in 

channel dimensions or incision. Use of rock gabions to halt 

ongoing incision in the Hot Creek Mountains resulted in the 

stream cutting around the structures (fig. 8.4a). Use of log 

cross-vanes in San Juan Creek resulted in the stream cutting under the structures (fig. 8.4b). Many investigators have 

noted that in-stream devices will require continued maintenance to prolong effectiveness (Frissell and Nawa 1992; 

Miller and Orbock Miller 2007). One cannot simply install 

these devices and expect them to function for long periods 

of time (multiple years to decades). They will need to be 

continually inspected and repaired. Given the inherent instability of most upland channels in the central Great Basin, 

continued maintenance will be particularly important to ensure device effectiveness in meadow complexes.

Use of Headcut and Gully Stabilization 

Measures

A common form of meadow degradation is development 

of gullies and upvalley migration of associated headcuts. 

Gullies are particularly common along relatively steep and 

narrow reaches of the valley floor, which often characterize downstream areas of meadow complexes. As a result, 

upvalley gully propagation, primarily by means of headcut 

advancement, is an especially important management issue. Unfortunately, gullies represent a particularly difficult 

form of degradation to treat, and it can be argued that effective management strategies have yet to be developed for 

these systems. Gullies are not only the product of surface 

flows but they result from the combined effects of both surface- and groundwater (seepage) erosion associated with 

shallow groundwater levels and layered stratigraphy. Thus, 

gully treatment must include measures to deal with multiple 

mechanisms of erosion that may occur at different times 

Figure 8.2. Radial fan profile near Kingston 3 meadow in 

Kingston Canyon. Erosion around structures within and 

immediately upstream of the fans is limited by coarse 

fan sediments and bedrock beneath the hillslope, which 

reduces the probability of failure.

Figure 8.3. Ternary diagram showing the likelihood that 

instream structures will fail. The diagram is based on detailed 

assessments of structures in North Carolina and, to a lesser 

degree, in Virginia and shows that the probability of failure 

is related to stream power, sediment supply, and bank 

erodibility (from Miller and Kochel 2008, 2010).
118 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

and under different hydrologic conditions. Complicating the 

problem further, data with which to evaluate the effectiveness of headcut and gully mitigation strategies in meadow 

complexes in the region are limited.

In general, commonly utilized treatment strategies fall 

into four categories: (1) using in-stream check dams and 

weirs to stabilize the base level and to retain sediment; 

(2) regrading and vegetating the gully banks and headcut to 

increase channel cross-sectional areas, reduce shear stress, 

and inhibit bank failure by mass wasting processes; (3) lining the headcut and banks with rock or other erosionally 

resistant material; and (4) spreading and/or diverting surface 

flows to reduce the amount of water entering the gully and to 

limit the concentration and erosive forces of surface flows on 

the valley floor. Exactly which method is most appropriate 

depends on the gully’s current morphology, its hydrologic 

and geologic setting, its position and integration within the 

drainage network, and the mechanisms responsible for headcut migration. Thus, selection of the stabilization approach 

must be based on a sound understanding of the gully or gully 

system to be treated.

Some of the most intensively treated gullies to date are 

located in Indian Valley at the southern end of the Toiyabe 

Range. Near the mouth of Indian Valley, a number of 

shallow, discontinuous gullies that terminate upstream 

in headcuts have entrenched the valley fill within a wide, 

low-gradient meadow complex. Treatment of these shallow 

gullies relied primarily on a combination of headcut and 

bank regrading, followed by placement of large rocks over 

the regraded area. Treatment likely began following major 

Figure 8.4. (a) Stream 

avulsion around a rock 

gabion structure in the 

Hot Creek Mountains. 

(b) Incision under an 

X-vein structure in San 

Juan meadow. Photos by 

J. Chambers.

(a)

(b)
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 119

flood events in the early 1980s, and vegetation associated 

with the regraded area suggests that the rock has been in 

place for at least a decade. When used on gullies with limited 

groundwater seepage and groundwater erosion, we observed 

that the structures were not affected by any erosion, although 

it is unclear whether they had been subjected to significant 

overland flow events. In some locations, however, seepage 

erosion had undermined the rock, leaving a disorganized 

array of boulders in the channel bed, while the headcut 

continued to migrate upvalley. Our qualitative observations 

suggest that where groundwater seepage is not important, 

gully regrading combined with localized “rip-rap” may be 

effective. This approach will be only marginally effective 

for reducing groundwater erosion and will require repeated 

maintenance to be effective against surface flows.

Large gullies in Indian Valley often were treated by 

constructing linear ridges across the valley floor, starting 

in the mouth of the gully. The intent was to spread surface 

flows over a larger area, thereby reducing erosive potential. 

Examination of sequential aerial photographs revealed that 

the approach was often successful at reducing erosion immediately downstream of the captured gully (i.e., the gully 

dammed by the earthen ridge) but usually resulted in development of new gully systems on another part of the valley 

floor (fig. 3.17). In fact, field observations revealed that 

even minor flow diversions within the meadow complexes 

could lead to unintended flow concentrations and gully formation elsewhere. Despite the meadows’ low gradients and 

extreme widths, they are extremely sensitive to erosion, and 

even minor changes in overland flow routes or depths can 

negatively affects meadow integrity. The difficulty of treating these gullies where both groundwater and surface water 

erosion are important stresses the need to manage the meadows such that gullies do not form in the first place. Once 

they establish, there may be little that can be done to rehabilitate the site.

However, not all gully and headcut systems are like those 

of the stream in Indian Valley. Many tend to be restricted 

to narrow, steeper reaches of the valley floor. Headcuts in 

these areas also are likely to be formed by a combination 

of surface- and groundwater erosion processes. However, 

in contrast to Indian Valley, where a very large supply of 

groundwater is continuously available and surface water 

flows can be enormous, the upstream supply of water to the 

site in these areas is more variable. Thus, the potential to 

reduce the rates of headcut advancement may be higher and 

more closely linked to factors such as upstream water supply, valley width, valley slope, and sediment composition of 

the valley fill. In very general terms, more water; narrow, 

steep valley floors; and permeable, non-cohesive sediments 

will increase the likelihood of headcut advancement as well 

as the difficulty of treating the problem.

Use of Biotechnical Methods

Stream bank stabilization within meadow complexes 

can be facilitated using biotechnical methods that focus on 

the use of live plant materials. Methods for biotechnical 

streambank stabilization are diverse and typically include 

the use of living plant material (tree or shrub stems and grass, 

sedge and rush plugs, or transplants) and inert erosion control materials (natural and synthetic geotextiles, rock rip-rap, 

log cribs, or coconut fiber rolls). The root systems of living 

plants increase streambank stability by providing resistance 

to shallow mass movement. Plant roots can reinforce the soil 

through tensile fibers in the root mass and anchor the slope 

through deep root penetration into more stable strata (Gray 

and Sotir 1996). Actively growing riparian vegetation can 

increase shear strength by reducing poor pressure (Gray and 

Sotir 1996). Also, foliage and stems of shrubs and trees on 

streambanks can decrease flow velocities and dissipate energy by redistributing flow patterns and directions (Li and 

Eddleman 2002).

A review of biotechnical streambank stabilization methods and their properties and applications is found in Li and 

Eddleman (2002). The stream environment is often complex, and different types of stabilization may be required 

for the zones associated with various stream stages. For example, more intensive measures may be required in the zone 

between average flows and typical high flows and in zones 

characterized by groundwater sapping. Combining different 

biotechnical methods, like inert erosion control materials and 

living plant material, is often most effective. In Kingston 3 

meadow, placing coconut fiber rolls in the zone between average flows and typical high flows and planting deep-rooted 

meadow species effectively stabilized a bare streambank 

that exhibited groundwater sapping (figs. 8.5a and b).

Information on harvesting, propogating, and planting 

wetland species that is appropriate for Great Basin meadow 

complexes is provided in Hoag (2003). Individual riparian 

species occur within well-defined water table regimes and 

depths to saturation (Chambers and others 2004b). Success 

of transplanting “wildlings” or plant materials harvested 

from the site or propagated in the greenhouse depends on 

matching water requirements of the species with the period 

of saturation and available soil water of the stream bank. 

Plantings are most vulnerable during the first two years of 

establishment and may require maintenance if high flows 

occur during the establishment period. Deferring grazing use 

for two years after bank stabilization is necessary to ensure 

success of the project.

General Considerations for 

Vegetation Management

The methods used for vegetation management within 

meadow complexes depend on the water table regime and 

the composition of meadow vegetation, as influenced by the 

disturbance history of the site. As discussed in Chapter 2, the 

hydrologic regime is the primary determinant of soil characteristics, plant community composition, and dynamics of 

riparian meadow complexes (Chambers and others 1999; 

Castelli and others 2000; Martin and Chambers 2001a, 

2001b, 2002). A classification of riparian ecological types 

in the central Great Basin based on climate, landforms, soils, 
120 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

and vegetation identified five meadow ecological types 

(Weixelman and others 1996). Three of the meadow ecological types are characterized by similar, high water tables 

and are differentiated based on elevation and soil texture. 

They are aquatic sedge (Carex aquatilis; high elevations), 

tufted hairgrass (Deschampsia ceaspitosa; coarser textured 

soils), and Nebraska sedge (Carex nebraskensis; mid to low 

elevations and fine textured soils). The remaining two types 

occur over a gradient of decreasing water table depth and 

are the mesic (mesic graminoid) and dry (dry graminoid) 

meadow types. An additional ecological type often occurs 

at the periphery of graminoid meadow complexes and is 

characterized by lower water tables: sage meadow (basin 

big sagebrush/Great Basin wildrye; Artemisia tridentata

ssp. tridentata/Leymus cinereus). At higher elevations, a 

similar ecological type occurs that is dominated by mountain big sagebrush (A. tridentata ssp. vaseyana) and Great 

Basin wildrye. “Average” water table depth and relative 

variability have been determined for the wet (Carex nebraskensis), mesic, dry, and sage meadow ecological types 

(fig. 8.6; Chambers and others 2004b). Wet and mesic meadows have the highest water table requirements and tolerate 

the least variability in water table depth (Castelli and others 

2000). Stream incision within meadow complexes has the 

potential to lower the base level of groundwater discharge 

into the stream (depending on the hydrologic setting), cause 

lowered water tables, and result in a change in the composition of meadow vegetation in areas affected by lower water 

tables (Chambers and others 2004a, 2004b). As a result, big 

sagebrush and other upland species can encroach and eventually dominate in areas formerly characterized by meadow 

vegetation (Chambers and Linnerooth 2001; Wright and 

Chambers 2002).

Figure 8.5. Bank stabilization 

of an area in Kingston 3 

meadow using coconut 

fiber rolls and graminoid 

plugs from the meadow (a) 

immediately after installation 

and (b) three years later. 

Photos by J. Chambers. (b)

(a)
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 121

An understanding of the factors that differentiate ecological types and of the potential states and transitions within 

ecological types can be used to design effective strategies 

for restoring and managing meadow complexes. A model 

state and transition diagram that illustrates the relationships 

among the wet, mesic, and dry meadow ecological types and 

that shows potential alternative states and transitions within 

each ecological type is shown in fig. 8.7. The diagram illustrates that meadow ecological types occur along water 

table gradients and are characterized by unique vegetation 

communities. Abiotic thresholds exist among the different 

ecological types that are determined by water table depth. 

Thresholds can be defined based on the parameters that determine the limits of natural variability (Ritter and others 

1999) for each ecological type. Threshold crossings occur 

when a system does not return via natural processes to the 

original state following disturbance (Laycock 1991; Ritter 

and others 1999).

Alternative vegetation states within each ecological type 

typically occur along anthropogenic disturbance gradients 

(fig. 8.7). Biotic threshold crossings to new alternative states 

can result from either internal interactions, like competition, 

or from external factors, like inappropriate livestock use or 

species invasions. If an ecological threshold to an alternative 

state has been crossed, management intervention typically is 

required to return the system to the former state (Wright and 

Chambers 2002; Chambers and others 2004a). Large changes in either biotic or abiotic conditions and, consequently, 

ecosystem processes can result in new ecological types with 

different sets of restoration potentials. For example, a lowering of the water table by as little as 30 cm can result in an 

abiotic threshold crossing from a wet meadow to a mesic 

meadow (fig. 8.6).

Use of Vegetation Management

Minor stream incision can result in transitions to drier 

vegetation communities within meadow ecological types. 

Management options include stabilizing the stream system 

and stream banks, as described above, and managing the 

meadow complex to prevent overgrazing by livestock and 

invasion of weedy species. Monitoring grazing use, ensuring that utilization guidelines are met, and treating weedy 

species as soon as they appear can prevent transitions to undesirable states.

Incision that causes a significant drop in the water table 

may cause all or part of the meadow to transition to a new 

ecological type with a new site potential. The change in the 

stream system and groundwater table may occur during one 

or multiple events. In those cases where it is not ecologically 

or economically feasible to stabilize the stream system, it 

may be necessary to wait until the stream has obtained a new 

base level or is at grade before initiating active vegetation 

management. In meadows with active springs or seeps that 

are not adjacent to the stream, portions of the meadow may 

remain relatively wet.

The first step in determining the potential of a site to 

support a given ecological type is to monitor the depth to 

saturation or the water table. This can be accomplished by 

using soil augers, digging soil pits to evaluate depth to saturation, or installing groundwater wells to measure water 

table depths. Because water table depths are highly variable 

both among and within years in mesic, dry, and sage meadow ecological types (Castelli and others 2000; Martin and 

Chambers 2002), monitoring should be conducted several 

times during the growing season and for at least two years 

prior to project initiation (Chambers and others 2004b). The 

water table depths shown in fig. 8.6 can be used to evaluate site potential. Plant species composition also can be 

used as an indicator of site potential with the caveat that 

riparian obligate and facultative species are often longlived and significant lag times can occur during transition 

to new ecological states. Establishment and persistence of 

upland species like the shrubs, big sagebrush (A. tridentata

ssp. tridentata, A. tridentata ssp. vaseyana), or rabbitbrush 

(Chyrsothamnus species), are strong indicators that site potential has transitioned to sage meadow.

Sites that have maintained their potential to support 

wet or mesic meadow types may exhibit slight changes in 

species composition and may only require stabilization of 

spring channels or stream banks. However, sites that have 

transitioned rapidly from wet or mesic meadow types to 

sites with the potential to support dry or sage meadows 

may exhibit weedy species invasions or undesirable species compositions (Wright and Chambers 2002). Active 

management that includes prescribed fire to remove upland 

shrubs and revegetation can be used to improve the ecological condition of these sites and to maintain them as dry 

or shrub meadows.

The dry meadow type, as originally described, is dominated by grasses and sedges and has relatively shallow water 

table depths and depths to saturation (-70 to -100 cm in June 

Figure 8.6. The water table depths (means + S.E.) for meadow 

ecological types typical of intermediate elevations in the 

central Great Basin (from Chambers and others 2004b).
122 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

and July) (Weixelman and others 1996). These water table 

depths facilitate establishment and persistence of typical dry 

meadow species such as Nevada bluegrass (P. secunda ssp. 

juncifolia). Saturated rooting zones during the spring and 

early summer prevent establishment and persistence of big 

sagebrush and other shrubs (Ganskopp 1986). Overgrazing 

and other perturbations can alter species composition but 

will not result in shrub encroachment unless the water table 

drops. Sites with slightly lower water tables (-150 to -250 

cm) are characterized by dry meadow species but are susceptible to sagebrush encroachment. Dry meadow species 

persist because occasional high water tables and favorable 

environmental conditions facilitate episodic establishment 

(Chambers and Linnerooth 2001). However, water tables are 

sufficiently low that basin big sagebrush also can establish 

and persist (Wright and Chambers 2002). Inappropriate 

livestock use increases sagebrush establishment by reducing competition from herbaceous species (see Belsky and 

others 1999). Designation of sites with lower water tables 

(-150 to -250 cm) as alternative states of the dry meadow 

ecological type depends on the interpretation of the “range 

of natural variability” within an ecological type. If the range 

is considered sufficiently broad to include sites with slightly 

lower water tables that can exhibit sagebrush encroachment, 

then these sites represent alternative states of the dry meadow ecological type. Regardless, sites that exhibit sagebrush 

encroachment but that have typical dry meadow species 

in the understory can be maintained as dry meadows with 

prescribed fire and proper livestock grazing (Wright and 

Chambers 2002).

Figure 8.7. Hypothetical state 

and transition models 

for the wet, mesic, and 

dry meadow ecological 

types. Differences 

among ecological types 

are largely dependent 

on water table depths; 

differences among states 

are largely dependent 

on disturbance and 

management history (from 

Chambers and others 

2004b).
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 123

Sites with deeper water tables (-250 to >-300 cm) are 

dominated by sagebrush with a minor component of dry 

meadow species. These sites have crossed abiotic thresholds 

and no longer have the potential to support the dry meadow 

ecological type. The failure of typical dry meadow species 

to establish (Chambers and Linnerooth 2001) indicates that 

any dry meadow species that occur on the sites are probably 

remnants of what existed prior to stream incision and lowered water tables. These sites are unstable and can exhibit 

several different pathways depending on the disturbance 

regime and initial species composition. In the worst case 

scenario, they can transition to sagebrush dominance with 

an understory of upland herbaceous or invasive species. Past 

research shows that at low to intermediate elevations within 

the watersheds, basin big sagebrush and Great Basin wildrye 

can establish on these sites (Wright and Chambers 2002). 

Thus, the potential exists for at least the more xeric species 

that characterize the basin big sagebrush/Great Basin wildrye ecological type to also establish (Weixelman and others 

1996). Prescribed fire can be used to remove the sagebrush 

overstory on these sites. Because the herbaceous understory 

species that characterize the basin big sagebrush/Great Basin 

wildrye ecological type are almost nonexistent, they must be 

seeded onto the site. Fire alone can convert these sites to annual forbs and grasses, especially if the fire-adapted, exotic 

grass cheatgrass (Bromus tectorum) or annual mustards exist 

in the understory (Wright and Chambers 2002).

Methods for successfully revegetating these types of 

sites can be found in Whisenant (1999) and Monsen and 

others (2004). Native species that have been successfully 

established on these sites and that are commercially available include the grasses—Great Basin wildrye (L. cinereus), 

western wheatgrass (Pascopyrum smithii), and creeping 

wildrye (Elymus triticoides)—and forbs—yarrow (Achillia 

millifolium) and blue flax (Linum lewissii) (Wright and 

Chambers 2002). Ample sources of sagebrush seeds typically exist adjacent to meadow complexes, and sagebrush 

usually establishes on its own. If rabbitbrush occurs on the 

site, it will re-sprout following fire and may preempt the site 

unless the herbaceous species establish rapidly. Maintenance 

of these sites requires preventing inappropriate livestock use 

and invasion of non-native species.

Other Management Considerations

The degree of stream incision and current ecological conditions of meadow complexes in Great Basin watersheds 

are affected significantly by anthropogenic disturbance. 

Ongoing studies provide direct evidence that roads have increased the rate and magnitude of stream incision. Several 

cases of “road captures” have been documented and many 

others have been observed where streams have been diverted onto road surfaces during high flows (Lahde 2003). 

These diversions onto road surfaces increase shear stress 

and stream power and, ultimately, stream incision (Lahde 

2003). Once initiated, stream incision can propagate through 

large portions of the system as a result of knickpoint migration. Active management of roads is needed to minimize the 

potential for stream diversion onto roads during high flows. 

This includes minimizing new road crossings and maintaining road conditions that decrease the likelihood of avulsion 

and stream diversion during high flows. It also includes 

long-term management that is aimed at relocating existing 

roads and positioning new roads out of the valley bottoms.

Inappropriate livestock use and other types of disturbance 

like off-road vehicle use and camping activities can alter 

physiolological responses and competitive interactions of 

meadow species (Martin and Chambers 2001a, 2002) and, 

thus, community composition and ecological condition of 

meadow ecological types (Martin and Chambers 2001b). 

These disturbances can increase the effects of changes in 

water tables resulting from stream incision. For example, 

inappropriate livestock use (timing, season, or duration) of 

riparian meadows often compacts soils and decreases infiltration capacity (Weixelman and others 1997) and alters 

plant physiological processes and population and community 

dynamics through vegetation removal and nitrogen deposition (Martin and Chambers 2001a, 2001b). Inappropriate 

livestock use also can decrease stream channel stability by 

removing stream bank vegetation, decreasing bank undercuts, and increasing bank erosion (NRC 2002). Informal 

fall monitoring of several riparian meadows in the central 

Great Basin by Chambers over multiple years indicated 

that repeated overuse by livestock (60 to 80% utilization) 

likely affects streambank stability and ecological conditions 

in many of these meadows. Proactive management of livestock use and other anthropogenic disturbances is essential 

to maintain and improve the ecological conditions of these 

meadows and to ensure that stream stabilization and vegetation management projects succeed.

Post-Project Evaluation, Monitoring 

and Adaptive Management

Until recently, evaluations, or post-project appraisals 

(PPA), of most stream and meadow restoration/stabilization 

projects were limited to qualitative assessments, if they were 

conducted at all. The potential benefits of such appraisals 

have received considerable attention in recent years, and 

it is apparent that PPAs are essential for developing sound 

management strategies. Several advantages exist for systematically collecting post-project data for stream stabilization/

restoration projects (Downs and Kondolf 2002) that are applicable to meadow complexes in the central Great Basin. 

These advantages are: determining (1) if the treatment was 

carried out or constructed as originally planned; (2) whether the treatment accomplished the project’s objectives or 

success criteria; (3) if the project resulted in unexpected, 

negative effects; (4) if the project could be altered to improve 

future treatments; and (5) whether the treatment proved to be 

an effective use of limited resources.

It is important to note that the development of a PPA does 

not start after the project has been implemented. Rather, it 

begins at the onset of the project with the creation of one 

or more explicit statements that define success criteria. As 
124 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011.

previously stated, success criteria are quantitative objectives 

against which post-project data can be compared to evaluate 

the performance of a specific approach. A PPA also requires 

collection of pre-project baseline data and post-project 

monitoring data, which can be compared to quantitatively 

determine how a system changes through time.

Many investigators and land managers now argue that 

PPAs should be combined with an adaptive management 

strategy (Walters 1986, 1997; Downs and Kondolf 2002). 

Halbert and Lee (1991) define adaptive management as an 

approach that:

...treats management programs as experiments. 

Rather than assuming that we understand the 

system that we are attempting to manage, adaptive management allows management to proceed 

in the face of uncertainty. Adaptive management 

uses each step of a management program as an 

information-gathering exercise whose results 

are then used to modify or design the next state 

in the management program.

Adaptive management is not the same as management 

by trial and error. Rather, adaptive management involves 

systematic collection and analysis of data through sound 

ecosystem monitoring and subsequent revision of a management approach on the basis of the collected scientific 

information. The primary advantage of this approach is that 

it allows management decisions to be revised as new information is obtained on how the system functions (Wieringa 

and Morton 1996).

It may not seem necessary to expend the time and effort 

to develop detailed design criteria and post-project appraisals for relatively small meadow treatments. However, given 

the importance of meadow ecosystems to the region and the 

limited quantitative data regarding the performance of meadow treatments, we believe that PPAs coupled with adaptive 

management strategies should be used in the Great Basin.

References

Arthur, M.B. 1936. Fish stream improvement handbook. 

Washington, DC: U.S. Department of Agriculture, Forest 

Service. 33 p.

Belsky, A.J.; Matzke, A.; Uselman, S. 1999. Survey of livestock 

influences on stream and riparian ecosystems in the western 

United States. Journal of Soil and Water Conservation. 51: 

419-431.

Beschta, R.L.; Platts, W.S.; Kauffman, J.B. 1992. Field review 

of fish habitat improvement projects in the Grande Ronde 

and John Day River basins of eastern Oregon. Portland, OR: 

U.S. Department of Energy, Bonneville Power Administration, 

DOE/BP-21943-1, February 1992. 53 p.

Castelli, R.M.; Chambers, J.C.; Tausch, R.J. 2000. Soil-plant 

relations along a soil-water gradient in Great Basin riparian 

meadows. Wetlands. 20: 251-266.

Chambers, J.C.; Blank, R.R.; Zamudio, D.C; Tausch, R.J. 1999. 

Central Nevada riparian areas: physical and chemical properties 

of meadow soils. Journal of Range Management. 52: 92-99.

Chambers, J.C.; Linnerooth, A.R. 2001. Restoring riparian 

meadows currently dominated by Artemisia using alternative 

state concepts—the establishment component. Applied 

Vegetation Science. 4: 157-166.

Chambers, J.C.; Miller, J.R.; Germanoski, D.; Weixelman, D.A. 

2004a. Process based approaches for managing and restoring 

riparian ecosystems. In: Chambers, J.C.; Miller, J.R., eds. 

Great Basin Riparian Ecosystems—Ecology, Management and 

Restoration. Covelo, CA: Island Press: 261-292.

Chambers, J.C.; Tausch, R.J.; Korfmacher, J.L.; Miller, J.R.; Jewett, 

D.G. 2004b. Effects of geomorphic processes and hydrologic 

regimes on riparian vegetation. In: Chambers, J.C.; Miller, J.R., 

eds. Great Basin Riparian Ecosystems—Ecology, Management 

and Restoration. Covelo, CA: Island Press: 196-231.

Christensen, N.L.; Bartuska, A.M.; Brown, J.H.; Carpenter, S.; 

D’Antonio, C.; Francis, R.; Franklin, J.F.; MacMahon, J.A.; 

Noss, R.F.; Parsons, D.J.; Peterson, C.H.; Turner, M.G.; 

Woodmansee, R.G. 1996. The report of the Ecological Society 

of America Committee on the scientific basis for ecosystem 

management. Ecological Applications. 6: 665-691.

Downs, P.W.; Kondolf, M.G. 2002. Post-project appraisals 

in adaptive management of river channel restoration. 

Environmental Management. 29: 477-496.

Frissell, C.A.; Nawa, R.K. 1992. Incidence and causes of physical 

failure of artificial habitat structures in streams of western 

Oregon and Washington. North American Journal of Fisheries 

Management. 12: 182-197.

Ganskopp, D.C. 1986. Tolerances of sagebrush, rabbitbrush, 

and greasewood to elevated water tables. Journal of Range 

Management. 39: 334-337.

Gray, D.H.; Sotir, R.B. 1996. Biotechnical and Soil Bioengineering 

Slope Stabilization. A Practical Guide for Erosion Control. New 

York, NY: Wiley. 378 p.

Halbert, C.L.; Lee, K.N. 1991. Implementing adaptive management. 

The Northwest Environmental Journal. 7: 136-150.

Hoag, J.C. 2003. Harvesting, propagating and planting wetland 

plants. Tech. Note. Plant Materials No. 13. Boise, ID: U.S. 

Department of Agriculture, Natural Resources Conservation 

Service. 11 p.

Lahde, D. 2003. The influence of secondary roads on stream 

incision in watersheds of the central Great Basin. Natural 

Resources and Environmental Sciences, University of Nevada, 

Reno. Thesis. 103 p.

Laycock, W.A. 1991. Stable states and thresholds of range condition 

on North American rangelands: a viewpoint. Journal of Range 

Management. 44: 427-433.

Li, M.; Eddleman, K.E. 2002. Biotechnical engineering as an 

alternative to traditional engineering methods. A biotechnical 

streambank stabilization design approach. Landscape and 

Urban Planning. 60: 225-242.

Martin, D.W.; Chambers, J.C. 2001a. Restoring degraded riparian 

meadows: biomass and species responses. Journal of Range 

Management. 54: 284-291.

Martin, D.W.; Chambers, J.C. 2001b. Effects of water table, 

clipping, and species interactions on Carex nebrascensis and 

Poa pratenis in riparian meadows. Wetlands. 21: 422-430.

Martin, D.W.; Chambers, J.C. 2002. Restoration of riparian 

meadows degraded by livestock grazing: above- and belowground responses. Plant Ecology. 163: 77-91.

Miller, J.R.; Kochel, R.C. 2008. Characterization and evaluation 

of stream restoration projects in North Carolina. Final Report 

to the North Carolina Clean Water Management Trust Fund, 

CWMTF. Project No. 2002B-805. 109 p.

Miller, J.R.; Kochel, R.C. 2010. Assessment of channel dynamics, 

in-stream structures and post-project channel adjustments 

in North Carolina and its implications to effective stream 

restoration. Environmental Earth Sciences. 59: 1681-1692.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-258. 2011. 125

Miller, J.R.; Orbock Miller, S.M. 2007. Contaminated Rivers: A 

Geomorphological-Geochemical Approach to Site Assessment 

and Remediation. Berlin, Germany: Springer. 418 p.

Monsen, S.B.; Stevens, R.; Shaw, N.L., comps. 2004. Restoring 

western rangelands and wildlands. Gen. Tech. Rep. RMRSGTR-136-vol-1. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Research Station. 

294 p.

National Research Council [NRC]. 2002. Riparian Areas: Functions 

and Strategies for Management. Washington, DC: National 

Academy Press. 428 p.

Riley, A.L. 1998. Restoring Streams in Cities. Washington, DC: 

Island Press. 423 p.

Ritter, D.F.; Kochel, R.C.; Miller, J.R. 1999. The disruption of 

Grassy Creek: implications concerning catastrophic events and 

thresholds. Geomorphology. 29: 323-338.

Rosgen, D.L. 1996. Applied River Morphology. Pagosa Springs, 

CO: Wildland Hydrology, Inc. 390 p.

Rosgen, D.L. 2001. The cross-vane, w-weir, and j-hook vane 

structures. Their description, design and application for stream 

stabilization and river restoration. Proceedings of ASCE 

Conference on Wetlands Engineering and River Restoration: 

27-31 August 2001; Reno, NV. Reston, VA: 1-22.

Rosgen, D. 2006. The cross-vane, w-weir, and j-hook vane structures 

(Updated 2006). Description, design and application for stream 

stabilization and river restoration. Wildland Hydrology, Inc. 

Available: http://www.wildlandhydrology.com.

Schumm, S.A.; Watson, C.; Harvey, M. 1984. Incised channels: 

morphology, dynamics and control. Littleton, CO: Water 

Resources Publications.

Seehorn, M.E. 1985. Fish habitat improvement handbook. 

Technical Publication R8-TP 7. Atlanta, GA: U.S. Forest 

Service, Southern Region. 30 p.

Seehorn, M.E. 1992. Stream habitat improvement handbook. 

Technical Publication R8-TP 16. Atlanta, GA: U.S. Forest 

Service, Southern Region. 30 p.

Simon, A. 1989. The discharge of sediment in channelized alluvial 

streams. Water Resources Research Bulletin. 25: 1177-88.

Simon, A.; Hupp, C.R. 1986. Channel evolution in modified 

Tennessee channels. Proceedings of the Fourth Federal 

Interagency Sedimentation Conference. 24-27 March 1986; Las 

Vegas, NV; in two volumes: 5.71-5.82.

Skidmore, P.B.; Shields, F.D.; Doyle, M.W.; Miller, D.E. 2001. 

A categorization of approaches to natural channel design. In: 

Hayes, D.F., ed. Proceedings of the 2001 wetlands engineering 

and river restoration conference. Reston, VA: American Society 

of Civil Engineers. CD-ROM.

Thompson, D.M. 2005. The history of the use and effectiveness of 

instream structures in the United States. Geological Society of 

America. Reviews in Engineering Geology. Vol. XVI: 35-50.

USDA Forest Service. 1952. Fish stream improvement handbook. 

Washington, DC.

Walters, C.J. 1986. Adaptive Management of Renewable Resources. 

New York, NY: Macmillan Pub. Co. 374 p.

Walters, C.J. 1997. Challenges in adaptive management of riparian 

and coastal ecosystems. Conservation Ecology [online]. 1(2):1. 

Available: http://www.consecol.org/vol1/iss2/art1/.

Weixelman, D.; Zamudio, D.; Zamudio, K.; Heise, K. 1996. 

Ecological type identification and ecological status determination. R4-ECOL-96-01. Ogden, UT: U.S. Department of 

Agriculture, Forest Service, Region 4.

Weixelman, D.; Zamudio, D.C.; Zamudio, K.A.; Tausch, R.J. 1997. 

Classifying ecological types and evaluating site degradation. 

Journal of Range Management. 50: 315-321.

Whisenant, S.G. 1999. Restoring Damaged Wildlands. A ProcessOriented, Landscape-Scale Approach. Cambridge, United 

Kingdom: Cambridge University Press. 312 p.

Wieringa, M.J.; Morton, A.G. 1996. Hydropower, adaptive 

management and biodiversity. Environmental Management. 20: 

831-840.

Wohl, E.; Angermeier, P.L.; Bledsoe, B.; Kondolf, G.M.; 

MacDonnell, L.; Merritt, D.M.; Palmer, M.A.; Poff, N.L.; 

Tarboton, D. 2005. River restoration. Water Resources 

Research. Vol. 41: W10301.

Wright, M.J.; Chambers, J.C. 2002. Restoring riparian meadows 

currently dominated by Artemisia using threshold and alternative state concepts—aboveground vegetation response. Applied 

Vegetation Science. 5: 237-246.
The use of trade or firm names in this publication is for reader 

information and does not imply endorsement by the U.S. 

Department of Agriculture of any product or service.
Federal Recycling Program Printed on Recycled Paper

Rocky

 Mountain

 Research Station

The Rocky Mountain Research Station develops scientific information 

and technology to improve management, protection, and use of the 

forests and rangelands. Research is designed to meet the needs of 

the National Forest managers, Federal and State agencies, public and 

private organizations, academic institutions, industry, and individuals. 

Studies accelerate solutions to problems involving ecosystems, range, 

forests, water, recreation, fire, resource inventory, land reclamation, 

community sustainability, forest engineering technology, multiple use 

economics, wildlife and fish habitat, and forest insects and diseases. 

Studies are conducted cooperatively, and applications may be found 

worldwide.

Station Headquarters

Rocky Mountain Research Station 

240 W Prospect Road

Fort Collins, CO 80526

(970) 498-1100

Research Locations

Reno, Nevada

Albuquerque, New Mexico

Rapid City, South Dakota

Logan, Utah

Ogden, Utah

Provo, Utah

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its 

programs and activities on the basis of race, color, national origin, age, disability, 

and where applicable, sex, marital status, familial status, parental status, religion, 

sexual orientation, genetic information, political beliefs, reprisal, or because all 

or part of an individual’s income is derived from any public assistance program. 

(Not all prohibited bases apply to all programs.) Persons with disabilities who 

require alternative means for communication of program information (Braille, 

large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 

720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, 

Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, 

DC 20250-9410, or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA 

is an equal opportunity provider and employer.

Flagstaff, Arizona

Fort Collins, Colorado

Boise, Idaho

Moscow, Idaho

Bozeman, Montana

Missoula, Montana