United States Department of Agriculture / Forest Service

Rocky Mountain Research Station

General Technical Report RMRS-GTR-269

December 2012

Threats to Western United States 

Riparian Ecosystems: A Bibliography

Boris Poff, Karen A. Koestner, Daniel G. Neary, and David Merritt
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Authors_____________________________

Boris Poff, District Hydrologist, Bureau of Land Management, 

Las Vegas, Nevada.

Karen A. Koestner, Hydrologic Research Technician, U.S. 

Department of Agriculture, Forest Service, Rocky Mountain 

Research Station, Forestry Sciences Laboratory, Flagstaff, 

Arizona.

Daniel G. Neary, Research Soil Scientist, U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Research Station, 

Forestry Sciences Laboratory, Flagstaff, Arizona.

Poff, Boris; Koestner, Karen A.; Neary, Daniel G.; Merritt, David. 2012. Threats to western United 

States riparian ecosystems: A bibliography. Gen. Tech. Rep. RMRS-GTR-269. Fort Collins, 

CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 78 p.

Abstract __________________________________________________

This bibliography is a compendium of state-of-knowledge publications about the threats affecting 

western U.S. riparian ecosystems and is a companion to the website: http://www.rmrs.nau.edu/

awa/ripthreatbib/. The website contains abstracts and access to many of the publications via PDFs, 

or it directs the readers to websites where PDFs of the publication can be viewed or obtained. 

The bibliography is ordered alphabetically and the type of threats discussed in each publication is 

highlighted. These threats include agriculture, climate change, dam construction, disease, drought, 

invasive species, fire, floods, flow regulation, forest harvesting, grazing, groundwater depletion, 

insects, mining, recreation, roads, water diversions, urbanization, and water quality.

Keywords: ecosystem, riparian, soil, water, watersheds, hydrology, threats, vegetation, wildlife, 

drought, floods, grazing, invasive plants

David Merritt, Riparian Ecologist, U.S. Department of Agriculture, Rocky Mountain Research Station, Forest Service, 

Stream Systems Technology Center, Fort Collins, Colorado.

Acknowledgments____________________

This effort was funded by a grant from the U.S. Department 

of Agriculture, Forest Service, Pacific Northwest Research 

Station, Western Wildland Environmental Threat Assessment 

Center. The authors would like to particularly thank Dr. Terry 

Shaw for his support and vision over the years regarding threats 

to western U.S.A. riparian ecosystems. 

Cover: Rocky Mountain Station scientists and technicians working with White Mountain—Fort Apache Nation personnel in 

evaluating the physical conditions of streams in high elevation riparian areas in the White Mountains, Arizona.
Summary ___________________________

In the western United States, riparian ecosystems occupy 

a small percentage of the landscape (<2%), but they provide 

essential ecological functions for both human and biotic populations. Despite their small portion of the landscape, western 

riparian ecosystems provide habitat for about one-third of 

the plant species. In arid regions like the Southwest and the 

Great Basin, about 60% of all vertebrate species and 70% of 

all threatened and endangered species are riparian obligates. 

This bibliography is a compendium of 480 state-of- knowledge 

publications about the threats affecting western U.S.A. riparian ecosystems and it is a companion to the website: http://

www.rmrs.nau.edu/awa/ripthreatbib/. The website contains 

Adobe Acrobat PDFs of the publications or it directs readers to journal websites where the PDFs can be downloaded, 

read, or ordered. This bibliography can be obtained as a hard 

copy or downloaded as an electronic version from the Rocky 

MountainResearch Station’s Publications website: http://www.

fs.fed.us/rm/publications/.

The bibliography presents publications on a range of riparian threats elucidated by Obedzinski and others (2001) and 

Theobald and others (2010). The topics include agriculture, 

climate change, dam construction, disease, drought, invasive 

species, fire, floods, flow regulation, forest harvesting, grazing, groundwater depletion, insects, mining, recreation, roads, 

water diversions, urbanization, and water quality. Most of the 

bibliographic entries deal with three or more threats and are 

listed as multiple threats. The two topics with the most references are grazing and invasive species. 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 1

Introduction

Riparian ecosystems serve critical ecological functions 

in all ecotones throughout the world. In the western 

United States, many components of these keystone 

ecosystems are and have been in decline since European settlement (Obedzinski and others 2001). This 

bibliography is a compilation of available research 

results, technical, position and policy papers published 

between 1938 and 2010 on the threats posed to riparian 

ecosystems. Over the course of two-thirds of a century, 

scientists and policy makers have publicly discussed the 

causes of this constant decline.

The threats identified herein range from agricultural 

development, climatic changes, dam construction, increases in insect and disease attacks, drought, fire, 

floods, flow regulation, forest harvesting, improperly 

managed grazing activities, groundwater depletion, 

invasion of exotic species, mining, recreation, roads, 

water diversion, urbanization and degradation in water 

quality.

While the majority of the papers listed in this bibliography focus on one specific riparian threat, there are 

several articles that examine the importance of interactions among various factors in causing the decline. 

Some papers also clarify issues that need to be addressed 

in order to restore and maintain sustainable riparian 

ecosystems in the western United States, including the 

function of vegetation, hydrologic conditions, riparian 

zone structure, landscape features, geomorphology and 

management objectives.

Riparian Ecosystems in the Western 

United States

In the western United States, riparian ecosystems 

(fig. 1) occupy a small percentage of the landscape, but 

they provide essential ecological functions for both 

Figure 1—Gunnison River, Colorado (photo by Lisa Lynch, 

National Park Service).

human and biotic populations (figs. 2 and 3). While riparian ecosystems occur on less than 2% of the total land 

area in the West (Svejcar 1997a), they provide habitat for 

about one-third of the plant species. In the arid Southwest 

and similar arid regions, about 60% of all vertebrate 

species (Obedzinski and others 2001) and 70% of all 

threatened and endangered species are riparian obligates 

(Johnson 1989). These ecosystems are not only unique 

because they have high species diversity and densities 

as well as high productivity, but they also allow for continuous interactions to occur between riparian, aquatic, 

and upland terrestrial ecosystems through exchange of 

energy, nutrients and species (Johnson and McCormick 

1978). Riparian ecosystems are systems with a high water 

table because of proximity to an aquatic ecosystem or 

subsurface water and have distinct vegetation and soil 

characteristics. Aridity, topographic relief and presence 

Threats to Western United States 

Riparian Ecosystems: A Bibliography

Boris Poff, Karen A. Koestner, 

Daniel G. Neary, and David Merritt
2 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

of depositional soils most strongly influence the extent 

of high water tables and associated riparian ecosystems 

(Johnson and McCormick 1978). Even though riparian 

zones are not easily delineated, they are composed of 

mosaics of landforms, communities and environments 

within the larger landscape (Gregory and others 1991).

Riparian zones range in width from a few to hundreds 

of meters. Large rivers such as the Colorado can have 

riparian zones that are narrow (fig. 4) or wide in the case 

of the Yellowstone River, depending on the geomorphology of the fluvial system (fig. 5). They can be 

wooded banks of rivers in the Pacific Northwest (fig. 6) 

(Obedzinki and others 2001). They are found along 

ephemeral stream channels, such as in southwestern 

Figure 2—Rio Grande River, New Mexico (photo courtesy of 

http://artsblog.freedomblogging.com/).

Figure 3—Gila River, New Mexico (photo by Daniel G. Neary, 

USDA Forest Service).

Figure 4—Colorado River, Arizona (photo by Daniel G. Neary, 

USDA Forest Service).

Figure 5—Yellowstone River, Wyoming (photo courtesy of 

http://wallpaper-s.org/).

Figure 6—Spanish Creek, North Fork, Feather River, 

California (photo courtesy of Plumas National Forest).
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 3

arroyos that carry water only during rain or snowmelt 

events or along perennial streams and flood plains with 

dense vegetation. This vegetation can vary from aquatic 

graminoid-sedge wet meadows (fig. 7) to extensive conifer 

forests (fig. 8). Riparian ecosystems provide an enormous 

service to watershed function because of their ability to 

filter out large quantities of sediments, nutrients, pesticides, 

animal wastes, and other non-point source pollution (Baker 

and others 2004). Hence, the health of such an ecosystem 

is usually measured in terms of watershed level function. 

Riparian vegetation also influences light penetration, 

air and water temperatures, and trophic interactions 

such as the transition between aquatic and terrestrial 

zones (figs.8 and 9). Large woody debris and litter associated with riparian vegetation are often necessary 

for productive fish habitats (fig. 8) and influence the 

physical, chemical and biotic characteristic of riparian 

and instream ecosystems (Naiman and Decamps 1997). 

Figure 7—Ord Creek, White River headwaters, Arizona 

(photo by Alvin Medina, USDA Forest Service). 

Figure 8—White River, Arizona (photo by Alvin Medina)..

Figure 9—West Fork, Black River, Arizona (photo by Alvin 

Medina, USDA Forest Service).

Figure 10—Cache La Poudre River, Colorado (photo courtesy 

of http:// www.wallpaperdave.com/poudre.htm).
4 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

However, in some riparian ecosystems, herbaceous plants 

provide the functions supplied by woody plants in other 

locations (fig. 7) (Medina 1996).

Riparian areas in the western United States attract 

a lot of attention from the human population in the 

region and across the country because of their scenic 

beauty, valuable resources and recreation opportunities 

(figs. 10 and 11). However, 

human use of riparian ecosystems and management 

of surrounding uplands 

have produced a number of 

threats to their sustainability 

(Stromberg and others 2004). 

The National Academy of 

Science’s synthesis of the 

functions and management 

strategies for national riparian areas brought out several 

important points relative to 

threats to riparian ecosystem sustainability (National 

Academy of Science 2002). 

The Academy pointed out 

that historical and current 

land use has affected the 

hydrologic, geomorphic, and biological structures of 

many riparian areas in the United States. In addition, 

global climate change processes are likely to aggravate 

threats to and stresses on riparian ecosystems rather than 

ameliorate them. The Academy acknowledged that most 

human development and land-use activities have cumulative effects on riparian ecosystems, but those impacts are 

rarely considered during landuse planning or management. 

Several areas of concern were 

noted relative to potential threats 

to riparian areas. Assessments of 

the health of riparian ecosystems 

are few in number and have been 

rather localized than regional or 

national in scope (fig. 12). More 

importantly, the National Academy of Science concluded that 

disturbed riparian ecosystems 

are quite resilient, can be restored 

and managed to maintain many 

of their functions and ecosystem 

services. However, they are not 

immune to the impacts of poor 

management and abuse of surrounding landscapes.

Figure 12—Verde River, Arizona, 

geomorphic, vegetation, and 

fish biota survey on the Prescott 

National Forest by the USDA 

Forest Service, Rocky Mountain 

Research Station (photo by Alvin 

Medina, USDA Forest Service).

Figure 11—Cimarron River, New Mexico (photo 

courtesy of http:// www.flickr.com/photos/

stevenm_61/299271362/).
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 5

Riparian Ecosystem Threats

Riparian Ecosystem Threats

Riparian areas are complex, diverse and constantly 

changing because of the highly dynamic fluvial systems in which they occur (Svejcar 1997a; Karr 1999). 

Understanding and managing riparian systems requires 

recognition of the role of disturbance and the evolutionary experience of riparian organism within the context 

of regional ecosystems. Like streamflow regimes and 

hydroclimate, riparian ecosystems exhibit local and regional distinctions and have been subjected to numerous 

and wide-scale disturbances by human occupation of 

the western North American landscape (Svejcar 1997b). 

Land managers must be able to understand and assess the 

following dimensions of disturbance: (1) type (abiotic, 

biotic or interactive); (2) regime (intensity, frequency, 

spatial scale, temporal scales relative to annual or life 

cycles); (3) ecological/physical system (hydrologic regime, geomorphic type, landscapes, populations, taxa 

etc.); and (4) regional/local context (within, adjacent to 

or encompassing riparian zones; Karr 1999).Short-term 

disturbances in riparian ecosystems are relatively easy 

to comprehend and observe (Svejcar 1997b). However, 

a short-term view can bias the observer’s perception 

of the real dynamic state of a riparian ecosystem. The 

100-year flood that “surprises” humans is nothing more 

than another creative disturbance in the long evolution 

of a riparian zone. Long-term disturbances, particularly 

those out of the current observational and historical 

range, may confuse any interpretation of the dynamic 

state of riparian ecosystems and the real magnitude of 

observed disturbance. For example, streams and riparian 

zones in the Great Basin are still adjusting to the drying 

up of late Pleistocene lakes and consequent lowering of 

base levels (Chambers 2008a). Streams and their riparian zones in the Southwest have had to respond to the 

disturbances of four major sequences of aggradation 

and degradation at intervals of 150 to 400 years over 

the past 2,100 years (Baker and others 2004).

Agriculture

Riparian ecosystems provided areas for agriculture 

for Native Americans before the arrival of European 

settlers (National Academy of Science 2002). With 

the settlement of the West in the latter half of the 19th 

Century, riparian areas were extensively developed and 

altered. This continues today along smaller rivers like 

the Verde River (fig. 12) in Arizona, but also along larger 

rivers with broad alluvial plains like the lower Colorado 

River in Arizona and California, the Sacramento River 

in California and the Columbia River in Oregon and 

Washington. Diversion of rivers and groundwater pumping in alluvial riparian plains for agriculture irrigation 

has contributed to water quality problems and groundwater depletion (Johnson and Riley 1984; Johnson and 

Haight 1984; National Academy of Science 2002). In 

the Southwest, salinization of tributaries and the main 

stem reaches of the Colorado River has been a major 

water quality problem.

Grazing is an agricultural practice that was concentrated in riparian areas because of the abundance of water 

and forage. It has had a significant impact on western 

riparian ecosystems (Kaufmann and Krueger 1984). 

Because of this, grazing is identified as a separate topic 

in this bibliography. However, grazing in western riparian zones is not confined to domestic livestock. Native 

ungulates, such as deer and elk, have had significant 

impacts on riparian vegetation and soils (Medina 1996; 

Neary and Medina 1996).

Climate Change

Weather patterns in western North America are normally characterized by periodic wet and dry periods, 

but climate changes in the future are likely to have more 

profound impacts (Chambers and Pellant 2008). The 

overall climate can periodically increase or decrease 

riparian stress, depending on the degree of variability 

and sensitivity of the plant or animal species. Alterations 

in weather patterns due to global climatic processes such 

as El Nino and La Nina have created significantly drier 

or wetter conditions historically (Risser 1991).

These climatic factors may predispose some species 

to the debilitating effects of other factors (insects, diseases, air pollutants, fire, mechanical injury, etc.), while 

coincidentally improving conditions for other species. 

For example, during dry periods, some grass species 

may begin to colonize sites previously dominated by 

moist-site species such as cottonwood (Populus spp.) and 

willow (Salix spp.). Johnson and others (1976) identified 

the importance of fresh alluvium for the establishment 

of pioneer species such as cottonwood (Populus spp.) 

and willow (Salix spp.). If this alluvial development is 

prevented by drier weather patterns, then species better 

adapted to non-disturbance, such as ash (Fraxinus spp.), 

boxelder (Acer negundo) or oak (Quercus spp.), might 

begin to dominate.

Climate change can influence riparian ecosystems due 

to the reliance of these systems on the presence of water 
6 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

(Naiman and others 2002). Excessive water (floods) or 

insufficient flows (drought) due to climate change can 

affect both the biological and physical compositions 

of riparian areas. Both of these topics are identified as 

separate riparian threats in this bibliography (Dixon and 

others 2009). Barnett and others (2008) attributed many 

of the observed changes affecting riparian ecosystems, 

such as in river flow, snow packs, temperature, etc., to 

human activities. Future climate changes will certainly 

produce vegetation shifts (Abrahams and others 1995; 

Chambers and Pellant 2008; Huxman and Scott 2007) 

that may or may not be mitigated with restoration techniques (Seavy and others 2009).

Dam Construction

Construction of a dam in Montana reduced the magnitude and intensity of floods to the point that cottonwood 

density decreased significantly over a 45-year period 

(Bradley and Smith 1986). In this case, even though 

recruitment of cottonwood seedlings continues to occur, 

survival is low. The problem is that not enough seedlings 

are growing in the critical zone. This zone needs to be 

sufficiently above water level to ensure rooting before 

high water disturbs seedling establishment. It must also 

be near enough to the surface water table to draw sufficient moisture to survive dry periods. Rood and others 

(1995) found similar results with dam construction on 

rivers in southern Alberta.

Hadley and Emmett (1998) found the opposite to be 

true with dam construction on a tributary of the South 

Platte River. A dramatic shift in the riparian plants 

from sparse grasses to dense woody vegetation occurred 

after dam construction. This rapid change was linked 

to channel scour, sediment deposition declines, fewer 

scouring peakflows that damaged woody plants, and an 

increase in dry season low flows.

The important effect of water diversion is the resultant change in the hydrologic regime and geomorphic 

conditions. In some parts of the West, riparian woody 

vegetation is more abundant now due to human-induced 

disturbances than in pre-European times (Rood and 

others 2007). Thus, some declines in woody riparian 

plants currently observed in the western United States 

can actually be resilience in the riparian ecosystem 

exhibiting slow recovery to a natural dynamic state. In 

evaluating the impact of riparian threats, it is imperative 

to fully understand the nature, dynamics, and trends of 

past disturbances.

Diseases and Insects

Although a large number of insect species are associated with riparian hardwoods in the western United 

States (Rogers 1996), the level of threat to riparian areas 

presented by various insects is largely undocumented 

(Obedzinski and others 2001). Most insect studies have 

been conducted in upland landscapes and usually concern large-scale insect outbreaks, such as the western 

spruce budworm and a large number of bark beetles that 

impacted western North American forests. The overall 

effect of insects within riparian zones appears to be 

much more subtle.

Even though many diseases affect riparian hardwood 

species in the West (Obedzinski and others 2001), little 

is known about the influence of disease processes on 

riparian vegetation. Similar to insects, most of our 

current knowledge of disease impacts in riparian ecosystems is inferred from research conducted in uplands. 

Diseases are primarily inciting factors because they 

tend to weaken plants rather than kill them outright. 

This weakening process makes riparian woody plants 

more susceptible to other biotic or abiotic factors. An 

example provided by Obedzinski and others (2001) is 

infection by true mistletoe (Phoradendron macrophyllum) in Arizona and New Mexico, which results in a 

loss of vigor (and occasionally death) of riparian species such as cottonwood, ash, sycamore (Platanus spp) 

and walnut (Juglans spp.). Invasive species bring new 

levels of threat to riparian vegetation by predisposing 

vegetation, especially woody plants, to secondary pathogens or to environmental stress. Disease levels can be 

indicators of threats and serve as an indicator of stress. 

With increases in disease levels following stress, trees 

become highly susceptible to insects, disease-causing 

organisms, and drought (Obedzinski and others 2001).

Drought

Drought is a major feature of climate change. A good 

number of the publications listed under climate change 

address this topic. Drought creates stress by reducing 

the ability of plants to photosynthesize and by limiting 

the moisture necessary for germination or the seasonal 

flooding required by flood-adapted species such as cottonwood (Obedzinski and others 2001). Kranjcec and 

others (1998) found that groundwater level declines and 

the lack of seasonal flooding had serious effects on cottonwood reproduction and establishment. Drought also 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 7

can influence native riparian species because they cannot compete with exotic species better adapted to drier 

conditions and minimal flooding. Cleverly and others 

(1997) and Stromberg and others (2007a) noted that summer flooding, no flooding, or reduced or altered water 

tables enabled tamarisk invasion of cottonwood-willow 

systems in Arizona.

Fire

The role of fire in the dynamics of riparian zones is 

poorly understood (Dwire and Kaufmann 2003). Riparian areas along the Gila River (fig. 3) in the Southwest 

periodically burned during dry periods (Baker and others 2004). In the Great Plains, tree-dominated riparian 

woodlands may be somewhat limited by fire (Boldt 

and others 1978). Fire can also affect germination and 

establishment of many obligate riparian tree species. 

Aspen seedling establishment has been observed to be 

greatest in riparian zones that had burned to mineral 

soil. Fires have a larger effect on shaping the ecological 

characteristics of riparian zones than was believed in 

the past (Petit and Naiman 2007).

Some past, as well as current research, has been 

exploring relationships among native and exotic plants 

and fire. For example, Busch and Smith (1995) found 

that tamarisk had a competitive advantage in water uptake over willow coppice sprouts on burned sites in the 

Southwest. Accumulation of flammable tamarisk leaf 

litter also may contribute to the occurrence of episodic 

fires that destroy native tree species such as willows 

(Smith and others 2009b).

Wildland fires can affect the amount of sediment that 

reaches streams, alter the loadings of coarse woody 

debris into riparian areas, and can significantly affect 

the vigor and type of riparian vegetation (Baker and 

others 2004). Prescribed fires and wildfires of low-tomoderate severity usually do not cause much post-fire 

sedimentation. By contrast, severe fires often produce 

enough sediment to overload the transport capacity of 

a stream. While this can provide ecological benefits for 

aquatic habitats in the short term, that same debris can 

cause long-term disruptions of fluvial, sediment, and 

biological processes.

Floods

Floods are major geomorphic forces in most western 

North American streams. Riparian ecosystems characterized by episodic, high volume, high velocity storm 

flows produce major shifts in woody riparian vegetation 

distribution and abundance (Baker and others 2004). 

Trees established in floodplains between major flows 

can be scoured out by high velocity flows and eliminated 

from near-channel terraces. This process is a function 

of the particular fluvial dynamics and not necessarily human activities. Geomorphology aggravates this 

situation when stormflows become confined within 

narrow channels by canyon walls. In the upper Verde 

River of Arizona, peak flood flows are a threat to fish 

populations, but they are also particularly important for 

establishing fish habitat (Rinne 1993).

Flow Regulation

One of the consequences of dam construction that provides both a threat and a benefit to riparian ecosystems 

is flow regulation. Dams have the effect of reducing 

peakflows for increased water storage and increasing 

or decreasing low baseflows. These changes in flow 

regime can have a substantial affect on both riparian 

plants and aquatic biota. Crawford and others (1996) and 

Groenveld and Griepentrog (1985) reported declines in 

riparian vegetation in flow regulated rivers. Beauchamp 

and Stromberg (2007) measured no significant changes 

in Populus spp. and Salix spp. stands on the Verde 

River of Arizona due to flow regulation, but Tamarix

establishment increased. Beauchamp and others (2006) 

noted marked declines in herbaceous species richness 

and abundance due to flow regulation. Fluctuating flows 

produced by flow regulation for electricity generation 

and irrigation have been known to reduce periphyton 

density in rivers (Benenati and others 1998).

Forest Harvesting

Native Americans relied heavily on trees, shrubs, and 

herbaceous plants in riparian woodlands. Settlement 

of the West in the 19th Century resulted in removal of 

woody riparian vegetation and the decline of some of 

these ecosystems. Sands and Howe (1977) indicated that 

there were about 775,000 ac of riparian woodlands in 

California in the first half of the 19th Century. By the 

end of that Century, these woodlands had been reduced 

significantly by use of trees for fuel wood, fence posts, 

and building materials as well as by converting land to 

agriculture. By 1977, only 12,000 ac of the 19th Century 

riparian woodlands remained intact.

A similar sort of reduction in riparian woodlands of 

the Southwest occurred to harvesting of riparian forests. 
8 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

Forest harvesting combined with grazing, conversions 

to agriculture, and water regulation reduced riparian 

woody vegetation to only 5 percent of what was originally found at the beginning of the western settlement 

(Johnson and Haight 1984). Similar situations occurred 

in the northern Black Hills and the Pacific Northwest.

Logging affects western riparian ecosystems through 

tree falling, log skidding, road construction, and direct 

removal of vegetation (DeBano and Schmidt 1989a,b). 

The first three factors compact and disturb soil, which 

increases erosion, depresses growth, and further stresses 

residual vegetation. Removal of vegetation can alter 

thermal regimes, increase soil loss, diminish ecological 

characteristics such as structural diversity, alter species 

composition, and improve site conditions for invasions 

by non-native plants and other biota.

Grazing

Most of the publications in this bibliography that address a single threat discuss grazing. Past overgrazing 

by livestock certainly raised the level of threats to western United States riparian ecosystems and exacerbated 

their decline. However, as livestock numbers are being 

reduced across the West to balance utilization with 

productivity, expanding populations of native ungulates, 

particularly elk (Cervus elaphus), have raised the potential to cause significant riparian impacts. Ecological 

impact concerns have been identified in four areas 

(Kauffman 1988): (1) soil compaction; (2) herbage 

removal; (3) physical damage to plants; and (4) changes 

in fluvial processes that may eliminate germination 

sites for woody vegetation.

Excessive trampling by ungulates’ hooves produces 

compaction that degrades soil aggregates, reduces associated soil pore space, and results in reduced plant vigor 

and growth (Elmore and Kauffman 1994; Kauffman 

and others 1983a,b). This situation decreases infiltration 

rates, increases surface runoff and erosion, and decreases 

the water status of plants (Kauffman and Kreuger 1984). 

By contrast, limited hoof action can assist the recovery 

of disturbed streambanks. It results in more microsites 

for seed germination and reduces the angle-of-repose 

of greatly incised streambanks. Plants will not colonize 

vertical banks of incised channels, but will quickly 

become established when streambanks are lowered to 

angles of 30-60 degrees (Baker and others 2004).

Herbage utilization by grazers, domestic or wild, can 

alter the ecological character of vegetation by altering structure and species composition (Kauffman and 

Kreuger 1984). Generally, this change occurs through 

the selective grazing habits, distribution and intensity of 

different types of herbivores, and the sensitivity of certain 

plant species to animal traffic and feeding. Kauffman 

and Kreuger (1984) noted that riparian overgrazing and 

site degradation favored the replacement of native bunch 

grasses with Kentucky bluegrass (Poa pratensis). In many 

locations, the most important cause for unsuccessful 

riparian plant reproduction was grazing and trampling 

by domestic livestock (Ehrhart and Hansen 1997). Grazing of cottonwood seedlings was reported to be a major 

factor limiting regeneration along a southern Arizona 

creek (Glinski 1977). In Yellowstone National Park, a 95 

percent decline of tall willows (S. bebbiana, S. boothii, 

S. lutea, and S. geyeriana) and a virtual elimination of 

willow seed production was due to repeated elk browsing 

(Kay and Chadde 1991). Despite substantial decreases 

in riparian grazing by livestock, large increases in the 

number of elk in the Southwest in the latter half of the 

20th Century have substantially altered the ecological 

characteristics of riparian vegetation (Clary and Kruse 

2004).

Grazing has been implicated in significant stream 

channel incision during the past century (Trimble and 

Mendel 1995; Neary and Medina 1996). Cattle, sheep, and 

elk all have contributed substantially to geomorphic alterations of riparian ecosystems (Medina 1996). Climate 

changes in the past century have also resulted in strong 

fluvial degradations and will certainly do more in the 

current century (Chambers and Pellant 2008). Grazing 

disrupts aggradation processes in riparian ecosystems 

through the cumulative effect of herbivory and alteration of the vegetation and soil matrix by hoof action 

(Neary and Medina 1996). Weakening of streambanks 

and disruption of substrates that armor channel bottoms precipitate channel incisions. Eventually, channels 

lose their riffle areas, streams migrate laterally, pools 

shallow out, water tables lower, and riparian vegetation 

composition shifts from hydric to more mesic species.

Groundwater Depletion

Groundwater depletion is a function of consumptive 

use by urban and agricultural users, flow regulation, 

and dam construction. These alterations of flow regimes 

have markedly lowered groundwater levels in some 

areas. Groundwater is important to riparian vegetation 

during periods of drought or in areas of low seasonal 

precipitation (Groeneveld and Griepentrog 1985; Stromberg and others 1992). Stress on mesquite woodlands 

increased with increasing groundwater withdrawal from 

an ephemeral creek in Arizona (Stromberg and others 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 9

1992) and elsewhere in the Southwest (Stromberg and 

others 2004). Although summer rains and seasonal high 

flows temporarily reduced water stress, the effects of 

declining water tables usually are not mitigated and ultimately lead to continued stress and riparian ecosystem 

declines.

Invasive Species

Invasive species are a major issue in any assessment 

of threats to riparian ecosystems. Russian-olive (Elaeagnus angustifolia), a native of Europe and western Asia, 

and tamarisk (Tamarix chinensis), first introduced into 

the United States in the early 1800s from Europe, are 

woody species of concern because of their ability to 

colonize riparian sites and exclude native species (Howe 

and Knopf 1991). Obedzinski and others (2001) pointed 

out that Russian-olive and tamarisk have invaded many 

sites because: (1) a decrease in the number of flooding 

events, due to dam construction and flow regulation, as 

described above; and (2) the life history of the species 

(Horton 1977). Tamarisk and Russian-olive negatively 

affect native riparian species germination and establishment in three ways: (1) the exotic species have a 

longer period to exploit suitable germinating conditions; 

(2) shading by exotics minimizes the potential for successful cottonwood regeneration; and (3) the exotics are 

better able to compete for shade and limited moisture 

(Howe and Knopf 1991) and to tolerate drought (Cleverly 

and others 1997).

Coupled with its ability to increase soil salt concentrations through autogenic processes, tamarisk has a 

high salt tolerance that gives it a competitive advantage 

over many native species (Stromberg and others 2004, 

2007b). Tamarisk combines fast growth in wet years 

with extreme tolerance of water and heat stress (Cleverly 

and others 1997). Reduction in streamflow by climate 

change, flow regulation, water diversion or dam construction further aggravates the tamarisk threat. In the 

Southwest, tamarisk has invaded many mesquite bosques 

and cottonwood/willow forests along the Rio Grande, 

the San Pedro, and the lower Colorado River (Stromberg 

and others 2007b). In Colorado, deteriorating riparian 

cottonwood stands are being replaced by Russian-olive, 

raising concerns about the future ecological status of 

these important riparian ecosystems. In New Mexico, the 

Rio Grande riparian system will likely be dominated by 

exotic species within the 21st century (Howe and Knopf 

1991).

These shifts towards invasive woody plants in riparian ecosystems could significantly influence wildlife 

habitat. Reductions in riparian plant diversity, faunalplant assemblages, uniqueness and critical habitat due 

to exotic invasions may not only influence terrestrial 

wildlife and vegetation, but also may affect macroinvertebrates within the stream. Changes in the quality of 

stream organic material inputs, together with alterations 

of the duration, intensity, and quality of light transmitted to the aquatic environment, can affect the quality, 

types and abundances of substrates for many microand macroinvertebrates (Obedzinski and others 2001). 

Further, in parts of the West, invasive fish, crustaceans, 

and mollusks are creating major threats as well (Rinne 

1993).

Mining

Mining has had impacts on riparian ecosystems 

throughout western North America. The major threats 

to riparian ecosystems have come from forest harvesting 

to provide mine timbers and fuelwood for underground 

mines and flow and sediment alteration due to placer 

mining and sand and gravel operations (Andrews and 

others 1985; Heifner 1978). Mines have also had drastic 

impacts on water quality and altered fish habitats (Martin 

and Platts 1981).

Multiple Threats

Most of the entries in this bibliography have been 

classified as multiple threats because they deal with 

three or more threats working in combination on riparian areas. Indeed, most riparian ecosystems in the West 

are being influenced by a variety of stressors. In most 

cases it is difficult to clearly distinguish the individual 

impact of each threat. The effects of an obvious threat 

might mask those of a more insidious one. For instance, 

Medina (1996) and Neary and Medina (1996) found that 

threats to riparian meadows in the White Mountains of 

Arizona posed by easily observed and obvious cattle 

grazing were masking those already imposed by elk 

grazing and climate change. Thus riparian ecosystem 

threats need to be examined carefully to determine 

causes and effect. In some instances this may not be 

possible. However, land managers need to be aware of 

this in order to make good, science-based decisions.

Recreation

Recreationists are frequently drawn to riparian areas 

in the West because of the water resource and lush 
10 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

vegetation (Winter 1993). Despite their value to land 

managers, recreation activities such as camping, hiking 

and off-road vehicles use are posing threats to some 

western riparian systems (Aitchison and others 1977; 

Johnson and Carothers 1982). Heavy recreational use 

can mimic damage caused by grazing, producing soil 

compaction and woody riparian vegetation deterioration by (1) reducing density and diversity of herbaceous 

plants; (2) lowering tree and shrub vigor; (3) eliminating seedlings and younger trees; (4) increasing tree 

diseases; (5) shifting plant species diversity in favor 

of disturbance-adapted species; and (6) increasing the 

potential for exotic species spread.

Recreation threats are often linked to other threats. 

Manning (1979) found that younger trees were reduced 

or eliminated on moderately or heavily used recreational 

sites. In areas of concentrated use, aspen stands have 

shown damage from a variety of recreation-related impacts including bark carving, soil trampling, firewood 

cutting, and removal of young suckers. The results of 

this damage are: (1) reduced or no advanced regeneration; (2) tree vigor reduction in all size classes; and (3) 

increased susceptibility to insect attack and disease 

spread. Changes in flow, climate change, and insect and 

disease stresses are commonly entwined with recreation 

impacts.

Roads

Roads are a special case of threats in that they are 

inciters for threats like recreation and urbanization and 

are usually associated with mining, forest harvesting, 

and agriculture (DeBano and Schmidt 1989; Hesseldenz 

1984). While usually limited in extent, roads can be a 

new source of sediment or deliver petroleum-based pollutants into riparian ecosystems (Petrosky and Holubetz 

1985; Stevens and others 2005).

Urbanization

While urbanization is a threat to minor streams located 

within the footprint of urban development, these threats 

are mostly noticed and addressed by land management agencies on major streams like the Colorado, Rio 

Grande, Columbia, Snake, Missouri, and Sacramento 

rivers. However, the associated threats produced by increased human presence in the West produce extensive 

and intensive impacts across the region (Stromberg and 

others 2004).

Water Diversion

Dams and irrigation diversion canals often associated 

with dams have significantly altered habitat for woody 

riparian vegetation in many parts of the West. Stromberg 

and others (2004, 2007a) surmised that the altering of 

water flows, especially by diversions, is among the greatest threats to Sonoran cottonwood-willow ecosystems. 

Rood and others (2005, 2007) rated river damming and 

associated water diversion right after livestock grazing 

and agriculture as primary causes of decline in cottonwood riparian ecosystems.

Water diversion is a special case of flow regulation. 

Many riparian species are sensitive to changes in the 

hydrologic regime that affects flooding periodicities and 

water table depth. Cottonwoods in particular have been 

significantly affected by water diversion. Like many 

Western riparian species, cottonwoods are adapted to 

spring flooding and high water tables. Water diversion 

has not only significantly reduced flooding events, but 

also has resulted in substantial lowering of riparian water 

tables to depths that prevent newly established woody 

plants like cottonwoods from obtaining moisture. In 

some cases, root systems of riparian tree species have not 

been able to grow fast enough to keep up with dropping 

water table levels (Groeneveld and Griepentrog 1985).

Water diversion and flow regulation also has allowed 

riparian systems to become dominated by exotic tree 

species such as Russian-olive and tamarisk, which 

out-compete species such as cottonwood and willow 

for available seedbeds. In the Southwest, primary, 

secondary, and tertiary tributaries of all major rivers 

have been affected by water diversions of some type. 

By the middle of the 20th Century, the effects of water 

diversion on the Gila-Salt-Verde River system were so 

great that less than 50 percent of their original length 

remained free flowing (Johnson and Haight 1984).

Water Quality

Water quality changes in streams, lakes, and ponds 

associated with riparian ecosystems are associated 

with other threats, chiefly agriculture, grazing, mining, fire, forest harvesting, urbanization, and recreation. While recreation and urbanization produce 

numerous, but localized non-point source pollution 

problems, agriculture, including livestock grazing, 

probably is the largest threat to riparian ecosystems 

due to nutrient release from fertilizers, bacteria associated with animal fecal material, and salinization 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 11

of irrigation return waters (Brown 1984; Mueller and 

Moody 1984). Mining is often (but not always) a point 

source of water pollution, as briefly addressed above.

Summary

This bibliography presents publications on a range 

of riparian threats elucidated by Obedzinski and others (2001) and Theobald and others (2010). The topics 

include agriculture, climate change, dam construction, 

disease, drought, invasive species, fire, floods, flow 

regulation, forest harvesting, grazing, groundwater 

depletion, insects, mining, recreation, roads, water diversions, urbanization, and water quality. Most of the 

bibliographic entries deal with three or more threats 

and are listed as multiple threats. The two topics with 

the most individual references are grazing and invasive 

species. In most cases, it is difficult to deal with isolated 

threats as most occur in combination with other threats. 

Land managers need to be aware of the multiple threats 

and their interactions in order to successfully manage 

riparian ecosystems in the western United States.

A periodically updated electronic version of this 

bibliography is available at the following web site: 

http://www.rmrs.nau.edu/awa/ripthreatbib/. The site 

contains an overview of the Southwest Watershed Science Team and their scientific endeavors including 

Streamside Management Zones, wildfires, prescribed 

fires, the Cascabel Watershed Study, Sierra Ancha Experimental Forest, the Upper Verde River, Laupahoehoe 

Experimental Forest in Hawaii, the Beaver Creek Experimental Watersheds, and the fire and fire surrogates 

study. A list of Team members, contact information, and 

publications is also provided.

Bibliography

1. Abrahams, A.D.; Parsons, A.J.; Wainwright, J. 1995. Effects 

of vegetation change on interrill runoff and erosion, 

Walnut Gulch, southern Arizona. Geomorphology. 

13: 37-48.

Abstract: During the past 100 years, grassland has been replaced by shrubland in many parts of the American Southwest 

due to overgrazing, climate change or a combination thereof. 

The effects of this vegetation change on interrill runoff and 

erosion are investigated by performing field experiments on 

small and large runoff plots located on contemporary grassland and shrubland hillslopes in Walnut Gulch Experimental 

Watershed. The experiments indicate that the vegetation 

change causes runoff and erosion to increase in interrill 

areas by decreasing resistance to overland flow, decreasing 

runoff infiltration, increasing the spatial heterogeneity of 

the plant canopy, and possibly increasing the susceptibility 

of the soil to frost action. GRAZING, CLIMATE CHANGE, 

WATER QUALITY

2. Acuna, V.; Munoz, I.; Giorgi, A.; Omella, M.; Sabater, 

F.; Sabater, S. 2005. Drought and postdrought recovery cycles in an intermittent Mediterranean stream: 

structural and functional aspects. Journal of the North 

American Benthological Society. 24(4): 919–933.

Abstract: The effects of the intensity of seasonal droughts 

on stream ecosystems were studied in an intermittent forested 

stream in a Mediterranean climate. Macroinvertebrate community structure and stream ecosystem metabolism were 

measured during seasonal summer droughts in 2001, 2002, 

and 2003. Ecosystem metabolism was profoundly affected 

by stream intermittency. Organic matter that accumulated 

during the dry period enhanced ecosystem respiration during the post-drought recovery. Highest biotic diversity was 

found at low water levels as the stream dried and contracted. 

DROUGHT

3. Adams S.B.; Burnett, K.M.; Bission, P.; Harvey, B.; Nislow, 

K.H.; Rieman, B.E.; Rinne, J.N. 2009. The role of the 

Forest Service in aquatic invasive species research. 

In: Dix, M.E.; Britton, K., eds. A dynamic invasive 

species research vision: Opportunities and priorities 

2009-29; Gen. Tech. Rep. WO-GTR-79/83. Washington, 

DC: U.S. Department of Agriculture, Forest Service, 

Research and Development; 55-66.

Abstract: The authors identify some key general research 

needs as well as areas in which the Forest Service is well 

positioned to contribute research that other organizations are 

not addressing. However, the authors believe a more formal 

process, bringing Forest Service aquatic and riparian scientists 

together with other biologists and stakeholders, is necessary 

to effectively identify and prioritize specific research needs. 

INVASIVE SPECIES

4. Aitchison, S.W. 1977. Some effects of a campground on 

breeding birds in Arizona. In: Johnson, R.R.; Jones, D.A., 

tech. coords. Importance, preservation and management of 

riparian habitat: A symposium; 1977 July 9; Tucson, AZ. 

Res. Pap. RM-43. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest and 

Range Experiment Station: 175-182.

Abstract: Over a 3-year period, breeding bird densities were 

found to be similar between a constructed campground and 

a relatively natural area when the campground was closed to 

campers. However, bird species composition differed between 

sites, the campground having relatively heavier bodied birds 

than the control area. Once the campground was opened for 

human use, the breeding bird population decreased in density and diversity. On the control site the population either 

remained the same or increased. RECREATION
12 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

5. Aitchison, S.W.; Carothers, S.W.; Johnson, R.R. 1977. Some 

ecological considerations associated with river recreation management. In: Proceedings of river recreation 

management and research symposium; 1977 January 

24-27; Minneapolis, MN. Gen. Tech. Rep. NC-28. St. 

Paul, MN: U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station: 222-225.

Abstract: Drawing from an ecological study on the Colorado River, four river recreation management concerns are 

discussed: (1) river research vs. river management, their 

interrelationships and priorities; (2) extensive resource inventories, their role as indicators of environmental deterioration; 

(3) human impact, its identification and proposed mitigation; 

and (4) suggested guidelines for identifying unique and ecologically sensitive areas. Other environmental degradations 

not directly associated with human impact such as habitat 

destruction by wild asses are also discussed. RECREATION, 

GRAZING

6. Allen, D.R.; Marlow, C.B. 1991. Effects of cattle grazing 

on shoot population dynamics of beaked sedge. In: 

Clary, W.P.; McArthur, E.D.; Bedunah, D.; Wambolt, 

C.L.; comps. Proceedings of the symposium on ecology 

and management of riparian shrub communities; 1991 

May 29-31; Sun Valley, ID. Gen. Tech. Rep. INT-309. 

Ogden, UT: U.S. Department of Agriculture, Forest 

Service, Intermountain Research Station: 89-91.

Abstract: To study the effect of cattle grazing on the number 

of new shoots produced by beaked sedge with the 1989 and 

1990 growing seasons, 40 plots were protected and 40 plots 

were grazed by cattle in June and September each year. Preliminary analysis of monthly shoot production data indicates 

that the greatest difference between grazed and ungrazed plots 

was in July. Seasonal mortality on grazed and ungrazed plots 

was similar, although high rodent-caused mortality in the 

ungrazed plots may have masked the effects of cattle grazing. The study area lies along an upper reach of Cottonwood 

Creek in the Montana Agricultural Experiment Station’s Red 

Bluff Research Ranch in southwestern Montana. GRAZING

7. Allred, M.D. 1993. Little Bear River hydrologic unit. In: 

Tellman, B.; Cortner, H.J.; Wallace, M.G.; DeBano, L.F.; 

Hamre, R.H., tech. coords. Riparian management: Common threads and shared interests. A western regional 

conference on river management strategies; 1993 Feb 

4-6; Albuquerque, NM. Gen. Tech. Rep. RM-226. Fort 

Collins, CO: U.S. Department of Agriculture Forest 

Service, Rocky Mountain Forest and Range Experiment 

Station: 359-363.

Abstract: This paper describes the Little Bear River project, 

the threats to the river, which include sedimentation and nonpoint source pollution, partly caused by livestock grazing and 

agriculture, land treatment and best management practices. 

It discusses public participation and scoping. MULTIPLE 

THREATS

8. American Fisheries Society: Western Division. 1982. 

The best management practices for the management 

and protection of western riparian streams. Alberta, 

Canada: Western Division of the American Fisheries 

Society. 45 p.

Abstract: This position paper presents the opinion of the 

WDAFS on the status of impacts on, and concern for westernaquatic-riparian habitats. It addresses seven primary impacts 

on riparian resources: livestock grazing, mining, water 

development and irrigation, road construction, agriculture, 

urbanization, and timber harvest. MULTIPLE THREATS

9. Ames, C.R. 1977.Wildlife conflicts in riparian management: 

Grazing. In: Johnson, R.R.; Jones, D.A., tech. coords. 

Importance, preservation and management of riparian 

habitat: A Symposium; 1977 July 9; Tucson, AZ. Res. 

Pap. RM-43. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 49-51.

Abstract: Grazing has a negative impact on riparian zones. 

These zones constitute a small but critically important part 

of the range resource. The riparian types in southern Arizona have increased from what they were 100 years ago. The 

increase has occurred through stream eutrophication and is 

most noticeable where the streams pass through the grassland type. Protection of the riparian type, where grazing is 

an established use, can only be effectively achieved though 

fencing. GRAZING

10. Amlin, N.M.; Rood, S.B. 2002. Comparative tolerances 

of riparian willows and cottonwoods to water-table 

decline. Wetlands. 22(2): 338-346.

Abstract: Cottonwoods (Populus sp.) and willows (Salix sp.) 

generally dominate riparian landscapes across western North 

America. To investigate their relative tolerances to water-table 

decline, rooted shoot cuttings (saplings) of two willows, and 

two cottonwoods, were grown in rhizopods, controlled growth 

devices that allow water-table manipulation. The willow 

and cottonwood saplings were similarly affected by abrupt 

water-table decline, but willow seedlings were slightly more 

vulnerable than cottonwood seedlings. GROUNDWATER 

DEPLETION

11. Anderson, B.W.; Ohmart, R.D. 1979. Riparian revegetation: 

An approach to mitigating for a disappearing habitat in 

the Southwest. In: Swanson, G.A., ed. The mitigation 

symposium: A national workshop on mitigating losses 

of fish and wildlife habitats. Gen. Tech. Rep. RM-65. 

Fort Collins, CO: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Forest and Range 

Experiment Station: 481-487.

Abstract: This study tested the feasibility of riparian revegetation efforts along the Colorado River to mitigate habitat 

losses for operational enhancement. Using 6 years of plant 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 13

and vertebrate data on two 20 to 30-hectare plots, significant plant and animal correlations were developed through 

community models. These correlations led to the design of 

species compositions that would yield optimum wildlife 

values and aid in mitigating disappearing riparian habitat. 

MULTIPLE THREATS

12. Anderson, B.W.; Ohmart, R.D. 1982. Revegetation for 

wildlife enhancement along the lower Colorado River. 

Boulder, NV: U.S. Bureau of Reclamation, Lower 

Colorado Region. 215 p.

Abstract: The use of riparian vegetation by wildlife and 

the effect of rapidly disappearing habitat on species, mostly 

due to saltcedar, are discussed. The report is the result of a 

2-year study using soil and salinity data of dredge spoil and 

refuge sites. The report investigates the effect of deep tillage, 

irrigation on growth distributions, and component analysis. 

Wildlife use and density are defined according to the study and 

a summary and synthesis is provided. INVASIVE SPECIES

13. Anderson, B.W.; Ohmart, R.D. 1985. Riparian revegetation 

as a mitigating process in stream and river restoration. 

In: Gore, J.A., ed. The restoration of rivers and streams. 

Boston: Butterworth Publishers: 41-80.

Abstract: This chapter summarizes the results of field studies 

of riparian habitats on the lower Colorado River and the efforts 

to use field-collected data to develop plant community designs 

that would house as many vertebrate species as possible and 

support high densities of wildlife. The authors present designs 

and methodologies that can be used in habitat improvement, 

mitigation, and operational enhancement in totally managed 

rivers systems where native revegetation has been curtailed 

or stopped. MULTIPLE THREATS

14. Anderson, B.W.; Higgins, A.; Ohmart, R.D. 1977. Avian 

use of saltcedar communities in the lower Colorado River 

Valley. In: Johnson, R.R.; Jones, D.A., tech. coords. 

Importance, preservation and management of riparian 

habitat: A symposium; 1977 July 9; Tucson, AZ. Res. 

Pap. RM-43. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 128-136.

Abstract: Bird densities and bird species diversities in saltcedar stands of the lower Colorado River Valley were determined 

on a seasonal basis from May 1974 through February 1977. 

Comparisons were made between six saltcedar structural 

types. A method of determining the relative value of the communities, as well as the saltcedar structural types, based on 

density, bird species diversity, number of species, structural 

diversity, and size of census area is described. Results show 

the saltcedar community supported fewer birds than native 

communities, although tall, dense stands were valuable for 

nesting doves and rarer bird species in riparian communities 

along the lower Colorado River. INVASIVE SPECIES

15. Anderson, B.W.; Ohmart, R.D.; Allen, H.A., Jr. 1984. 

Riparian birds in the riparian/agriculture interface. In: 

Warner, R.E.; Hendrix, K.M., eds. California riparian 

systems: Ecology, conservation, and productive management. Berkeley and Los Angeles, CA: University of 

California Press: 30-36.

Abstract: The interface between riparian and agricultural 

systems supports relatively large number of bird species and 

individuals because it offers a variety of food and structural 

resources that are especially apparent in winter. The interface 

can be used to compensate effectively for loss of natural 

habitats by interspersing agricultural lands with native vegetation. AGRICULTURE

16. Anderson, J.W.; Beschta, R.L.; Boehne, P.L.; Bryson, 

D.; Gill, R.; Howes, S.; McIntosh, B.A.; Purser, M.D.; 

Rhodes, J.J.; Sedell, J.W.; Zakel, J. 1993. A comprehensive approach to restoring habitat conditions needed to 

protect threatened salmon species in a severely degraded 

river—The Upper Grande Ronde River anadromous fish 

habitat protection, restoration and monitoring plan. In: 

Tellman, B.; Cortner, H.J.; Wallace, M.G.; DeBano, L.F.; 

Hamre, R.H., tech. coords. Riparian management: Common threads and shared interests. A western regional 

conference on river management strategies; 1993 Feb 

4-6; Albuquerque, NM. Gen. Tech. Rep. RM-226. Fort 

Collins, CO: U.S. Department of Agriculture, Forest 

Service, Rocky Mountain Forest and Range Experiment 

Station: 175-179.

Abstract: The Upper Grande Ronde River has undergone 

severe sedimentation caused by the cumulative effects of 

high levels of erosion generated from road construction, 

mining, logging, grazing, and wildfire. The Upper Grande 

Ronde River Plan was developed in response to several 

environmental and social issues and is summarized in this 

paper. MULTIPLE THREATS

17. Anderson, M.C. 2009. Livestock and elk grazing effects 

on stream morphology, brown trout population dynamics, movement and growth rate, Valles Caldera National 

Preserve, New Mexico. Masters Thesis. Las Cruces, 

NM: New Mexico State University. 173 p.

Abstract: Goals of this research were to assess changes in 

stream morphology and response of a brown trout population, to exclude cattle and elk from riparian areas, and to 

monitor spatial variability among individual and population 

level characteristics in brown trout to changing biotic and 

abiotic conditions. However, livestock and elk grazing had 

no impacts on stream morphology or brown trout populations 

and individual levels characteristics. GRAZING

18. Andrews, J.; Fishburn, E.; Frazier, B.; Johnson, R. 1985. 

North Fork John Day River habitat improvement: Annual 

report FY 1985. In: Natural Propagation and Habitat 

Enhancement, Volume I—Oregon. Project No. 84-8. 
14 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

Portland, OR: U.S. Department of Energy, Bonneville 

Power Administration, Division of Fish and Wildlife: 

222-261.

Abstract: Gold dredging activities have changed the natural 

course and hydrology of the North Fork John Day River in 

Oregon. High flow channels were created by the gold dredging. 

To date, the anadromous fish rearing habitat in this portion of 

the river has not recovered from the impacts of this dredging. 

The overall project goal described by this report has been to 

increase the production of spring Chinook salmon. MINING

19. Anzinger D.; Radosevich, S.R. 2008. Fire and nonnative 

invasive plants in the Northwest coastal bioregion. In: 

Zouhar, K.; Kapler, J.; Sutherland, S.; Brooks, M.L., 

eds. Wildland fire in ecosystems: Fire and nonnative 

invasive pants. Gen. Tech. Rep. RMRS-GTR-42-vol. 6. 

Fort Collins, CO: U.S. Department of Agriculture, Forest 

Service, Rocky Mountain Research Station: 197-224.

Abstract: This chapter discusses the relationship between 

fire (natural and prescribed) and nonnative plants species 

with major vegetation communities of the Northwest costal 

bioregion, including riparian forests. It specifically addresses 

the roles of fire in promoting nonnative species invasions, 

the effects of nonnative species on fire regimes, and usefulness of fire as a management tool for controlling nonnative 

species. FIRE, INVASIVE SPECIES

20. Armour, C. 1986. Impacts of present management on 

fisheries. In: Smits, J.H., ed. Management of riparian 

areas. Washington, DC: Public Lands Council: 37-38.

Abstract: This paper briefly discusses the impacts of riparian 

management in the mid-1980s and what research is needed to 

preserve functioning fisheries in the western United States. 

MULTIPLE THREATS

21. Athearn, F.J. 1988. Habitat in the past: Historical perspectives of riparian zones on the White River. In: Mutz, 

K.M.; Cooper, D.J.; Scott, M.L.; Miller, L.K. tech., 

coords. Restoration, creation and management of wetland and riparian ecosystems in the American West: 

Proceedings of a symposium of the Rocky Mountain 

Chapter of the Society of Wetland Scientists; 1988 

November 14-16; Denver CO: 73-75.

Abstract: This paper provides a brief description of how 

western riparian areas along the White River in Colorado 

have changed in the past 200 years. MULTIPLE THREATS

22. Bahre, C.J. 1991. A legacy of change: Historic human 

impact on vegetation in the Arizona Borderlands. Tucson, AZ: University of Arizona Press.

Abstract: This book examines historical land uses and the 

impact they have had on natural vegetation in southeastern 

Arizona. The author investigates livestock grazing, fire, 

fuelwood cutting, exotic plant introductions, agriculture, 

logging, and haying and shows how poorly understood 

the relationship between human activities and vegetation changes are. The most apparent directional changes, 

however, have been the introduction of exotic species and 

the removal of native vegetation for settlement purposes.

MULTIPLE THREATS

23. Baker, M.B., Jr.; Ffolliott, P.F.; DeBano, L.F.; Neary, 

D.G., eds. 2004. Hydrology, ecology and management 

of riparian areas in the southwestern United States. 

Lewis Publishers: 408 p.

Abstract: The authors provide decision makers, land-use 

planners, land managers, technical experts, and other riparian 

stakeholders with state-of-the-art information for sustaining 

environmentally sound riparian areas. Some of the threats to 

riparian zones considered in the 18 chapters include invasive 

species, grazing, dam construction, flow alteration, drought, 

recreation, roads, forest harvesting, and urbanization. MULTIPLE THREATS

24. Barnett, T.P.; Pierce, D.W.; Hidalgo, H.G.; Bonfils, C.; 

Santer, B.D.; Das, T.; Bala, G.; Wood, A.W.; Nozawa, 

T.; Mirin, A.A.; Cayan, D.R.; Dettinger, M.D. 2008. 

Human-induced changes in the hydrology of the Western 

United States. Science. 2319: 1080-1083.

Abstract: The authors present a regional, multivariable 

climate change detection and attribution study, using a highresolution hydrologic model forced by global climate models, 

focusing on the changes that have already affected this primarily arid region. The results show that up to 60% of the 

climate related trends of river flow, winter air temperature, 

and snow pack between 1950 and 1999 are human-induced. 

CLIMATE CHANGE

25. Barro, S.C.; Wohlgemuth, P.M.; Campbell, A.G. 1988. 

Post-fire interactions between riparian vegetation and 

channel morphology and the implications for stream 

channel rehabilitation choices. In: Abell, D.L., coord. 

Proceedings of the California riparian systems conference: Protection, management, and restoration for the 

1990s; 1988 September 22-24; Davis, CA. Gen. Tech. 

Rep. PSW-110. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and 

Range Experiment Station: 51-53.

Abstract: This study investigated post-fire interactions 

between riparian vegetation and channel morphology in the 

upper Santa Ynez River drainage basin. The intensity of the 

fire through the riparian area was indicated by the damage to 

trees and the understory. In addition to removing vegetation, 

the fire caused changes in soil characteristics, which have led 

to accelerated erosion on hillside slopes. FIRE

26. Barrows, C.W. 1993. Tamarisk control: II. A success 

story. Restoration and Management Notes. 11: 35-38.

Abstract: This paper describes a tamarisk control project in 

a heavily infested 10-hectare wetland in Riverside County, 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 15

California. The results have been encouraging and suggest, 

while complete and perpetual eradication of tamarisk is 

unlikely in most situations, control followed by restoration 

of historic vegetation is a viable option in many watersheds. 

INVASIVE SPECIES

27. Barry, W.J. 1984. Management and protection of riparian ecosystems in the state park system. In: Warner, 

R.E.; Hendrix, K.M. eds., California riparian systems: 

ecology, conservation, and productive management. 

Berkeley and Los Angeles, CA: University of California 

Press: 758-766.

Abstract: Preserving California’s natural heritage is one 

of the California Department of Parks and Recreation’s 

three primary missions. The general objectives of policies 

formulated for riparian ecosystems are to restore, protect, 

and maintain riparian ecosystems in as near a natural state 

as possible. This paper discusses the on- and off-site impacts 

with specific examples of resource management problems, 

policies, and programs. RECREATION

28. Bateman, H.L.; Chung-MacCoubrey, A.; Snell, H.L.; 

Finch, D.M. 2008. Abundance and species richness 

of snakes along the Middle Rio Grande riparian forest in New Mexico. Herpetological Conservation and 

Biology. 4: 1-8.

Abstract: This study provides basic information on trapping success, species richness, and capture rates for snakes 

inhabiting the bosque along the Middle Rio Grande in New 

Mexico. MULTIPLE THREATS

29. Bateman, H.L.; Harner, M.J.; Chung-MacCoubrey, A. 

2008. Abundance and reproduction of toads (Bufo) 

along a regulated river in the southwestern United 

States: Importance of flooding in riparian ecosystems. 

Journal of Arid Environments. 72: 1613-1619.

Abstract: Abundance and size of toads were related to precipitation, river flow, and groundwater over 7 years along 

the Middle Rio Grande. Results demonstrated that small, 

managed floods can positively affect abundance of toads by 

providing off-channel, aquatic habitats along regulated rivers. 

FLOW REGULATION

30. Beauchamp, V.B.; Stromberg, J.C. 2007. Flow regulation of the Verde River, Arizona encourages Tamarix

recruitment but has minimal effect on Populus and 

Salix stand density. Wetlands. 27: 381-389.

Abstract: This investigation compared Populus, Salix, 

and Tamarix stem density in 63 stands on unregulated and 

regulated reaches of the Verde River. Results from this study 

suggest that where major flooding still occurs in regulated 

reaches, or where managed flooding is an option, recruitment 

of Populus and Salix is possible at similar levels to unregulated reaches. FLOW REGULATION, INVASIVE SPECIES

31. Beauchamp, V.B.; Stromberg, J.C. 2008. Changes to 

herbaceous plant communities on a regulated desert 

river. River Research and Applications. 24: 754-770.

Abstract: This investigation examined differences in herbaceous species richness, abundance and composition in 

Populus-Salix stands along an unregulated and regulated 

reach of the Verde River in Arizona. It also contrasted flood 

inundation frequency and edaphic conditions (soil moisture, 

nutrients, and texture) between reaches and interpreted the 

vegetation difference in light of observed differences in environmental conditions. Results demonstrate that sediment 

transport within riparian corridors is important for maintenance of herbaceous communities and that restoration of flow 

regimes alone may be insufficient to restore herbaceous flora 

on some regulated reaches. FLOW REGULATION

32. Beauchamp, V.B.; Stromberg, J.C.; Stutz, J.C. 2005. Interactions between Tamarix ramosissima (Saltcedar), 

Populus fremontii (Cottonwood), and mycorrhizal 

fungi: Effects on seedling growth and plant species 

coexistence. Plant and Soil. 275: 221-231.

Abstract: Throughout the western United States, riparian 

forests dominated by Populus species are declining due to 

disruptions in natural flood cycles and groundwater levels 

by dams, groundwater pumping and water diversions. The 

regional decline of riparian gallery forests has occurred concomitantly with the spread of Tamarix (saltcedar) into riparian 

areas. Little is known about the composition and function 

of the mycorrhizal fungal community in riparian areas, or 

its importance in competitive interactions between Populus 

fremontii, a dominant tree in southwestern United States 

riparian forests that forms arbuscular and ectomycorrhizas, 

and Tamarix. The results of this study indicate that Tamarix

is non-mycotrophic and that in this greenhouse experiment 

inoculation altered patterns of coexistence between Populus

and Tamarix. INVASIVE SPECIES

33. Beauchamp, V.B.; Stromberg, J.C.; Stutz, J.C. 2006. Flow 

regulation has minimal influence on mycorrhizal fungi 

of a semi-arid floodplain ecosystem despite changes 

in hydrology, soils, and vegetation. Journal of Arid 

Environments. 68: 188-205.

Abstract: In this study, floodplain soil texture and chemistry, 

herbaceous cover and richness, and arbuscular mycorrhizal 

fungi (AMF) richness and colonization were compared between unregulated and regulated reaches of the Verde River, 

Arizona. Despite differences in floodplain soils characteristics, AMF colonization, richness, and community composition 

were similar between reaches. FLOW REGULATION

34. Behnke, R.J. 1978. Grazing and the riparian zone: Impacts 

on aquatic values. In: Graul, W.D.; Bissel, S.J., tech. 

coords. Lowland river and stream habitat in Colorado: 

A symposium; 1978 Oct 4-5. Greeley, CO: Wildlife 

Society and Colorado Audubon Council, Colorado 

Chapter: 126-132.
16 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

Abstract: Multiple use conflicts arise where grazing has long 

been a dominant use and other values have been neglected. Of 

special concern is the fact that livestock concentrate in riparian zones and this problem is particularly acute in arid and 

semi-arid regions where the most ubiquitous and significant 

damage occurs to riparian vegetation. GRAZING

35. Behnke, R.J.; Raleigh, R.F. 1978. Grazing and the riparian zone: Impact and management perspectives. In: 

Johnson, R.R.; McCormick, J.F., tech. coords. Strategies 

for protection and management of floodplain wetlands 

and other riparian ecosystems. Gen. Tech. Rep. WO12. Washington, DC: U.S. Department of Agriculture, 

Forest Service: 263-267.

Abstract: Livestock overgrazing on riparian vegetation is 

magnified in arid and semi-arid regions. Typical stream habitat 

changes resulting from overgrazing of riparian vegetation, 

trampling of stream banks, and increased erosion include: 

widening and shallowing of the streambed, gradual stream 

channel trenching or braiding, silt degradation of spawning 

and invertebrate food producing areas, loss of streamside 

and instream cover, increased water temperatures and velocities, decreased terrestrial food inputs, and a 3-4 fold 

decrease in trout biomass in grazed versus ungrazed areas. 

Recent livestock/fisheries study results and livestock grazing 

management options to repair, maintain and protect riparian 

habitats are presented. GRAZING

36. 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. 54: 419-431.

Abstract: This paper summarizes the major effects of livestock grazing on stream and riparian ecosystems in the arid 

West. The authors focused primarily on results from peer 

reviewed, experimental studies, and secondarily on comparative studies of grazed vs. naturally or historically protected 

areas. Results were summarized in tabular form. Livestock 

grazing was found to negatively affect water quality and 

seasonal quantity, stream channel morphology, hydrology, 

riparian zone soils, instream and streambank vegetation, and 

aquatic and riparian wildlife. GRAZING

37. Belt, G.H.; O’Laughlin, J.; Merrill, T. 1992. Design of 

forest riparian buffer strips for the protection of water 

quality: Analysis of scientific literature. Report No. 8. 

Moscow, ID: University of Idaho, Idaho Forest, Wildlife 

and Range Policy Analysis Group. 35 p.

Abstract: This report identifies, evaluates and synthesizes 

research-based information relating riparian buffer strips to 

forest practices, water quality and fish habitat. This literature 

review suggests that scientists are at different stages in their 

understanding of the several important functions provided 

by buffer strips, which include temperature moderation, sediment filtration, and LOD recruitment. MULTIPLE THREATS

38. Benenati, P.L.; Shannon, J.P.; Blinn, D.W. 1998. Desiccation and recolonization of phytobenthos in a regulated 

desert river: Colorado River at Lees Ferry, Arizona, 

USA. Regulated Rivers. 14: 519-532.

Abstract: The daily and seasonal fluctuating flows characteristic of hydroelectric peaking power facilities can have 

detrimental effects on the growth and survival of downstream 

benthos. The operation of Glen Canyon Dam and the presence 

of Lake Powell have modified the Colorado River benthic 

food base in Grand Canyon since 1963. Prior to impoundment, production in the muddy Colorado River was driven 

primarily by allochthonous input, with occasional clear-water 

periods and limited algal growth. However, productivity has 

decreased in the varial zone owing to periodic atmospheric 

exposure resulting from fluctuating flows. The authors tested 

the recolonization of the phytobenthic community in the 

tailwaters of Glen Canyon Dam following long and shortterm experimentally induced desiccation. The response of 

Cladophora glomerata, Oscillatoria spp., miscellaneous phytobenthos species, and periphyton was studied over 18 weeks 

using three treatments: (1) undisturbed control cobbles from 

the submerged zone; (2) cobbles desiccated and replaced into 

the submerged zone; and (3) cobbles desiccated and replaced 

into the varial zone. Periphyton density and compositional 

response resulting from these treatments were also examined. 

Recovery and maintenance of benthic resources are hindered 

by fluctuating flow regimes driven by electricity and irrigation 

requirements. Repeated desiccation of the phytobenthos has 

major effects on the bottom-up interactions in the Colorado 

River ecosystem. FLOW REGULATION

39. Bergthold, P.M. 1978. Arizona State Park’s Natural Area 

Program. In: Johnson, R.R.; McCormick, J.F., tech. 

coords. Strategies for protection and management of 

floodplain wetlands and other riparian ecosystems. Gen. 

Tech. Rep. WO-12. Washington, DC: U.S. Department 

of Agriculture, Forest Service: 243-247.

Abstract: A Natural Area Program within Arizona State 

Parks identifies and registers important sites within the State. 

Over half of the identified Natural Areas contain riparian 

elements. Developing protective strategies, cooperating with 

land managing agencies, and public education show promise 

for maintaining an important southwestern resource. MULTIPLE THREATS

40. Beschta, R.L.; Bilby, R.E.; Brown, G.W.; Holtby, L.B.; 

Hofstra, T.D. 1989. Stream temperature and aquatic 

habitat: Fisheries and forestry interactions. In: Salo, 

E.O.; Cundy, T.W., eds. Streamside management: 

Forestry and fishery interactions. Institute of Forest 

Resources Contribution 57. Seattle, WA: University of 

Washington: 191-232.

Abstract: The temperature of water entering a forest stream 

system typically resembles that of the watershed’s subsoil 

environment. Logging activities can initiate pronounced 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 17

temperature changes by the removal of forest vegetation 

along channels. Although direct mortality of fish is probably 

not a major concern throughout the Pacific Northwest when 

stream temperatures are altered by management activities, 

temperature changes can influence rates of egg development, 

rearing success, species competition, and other factors. 

FOREST HARVESTING

41. Betancourt, J.L. 1990. Tucson’s Santa Cruz River and 

Arroyo Legacy. PhD. Dissertation. Tucson: University 

of Arizona. 239 p.

Abstract: Tucson’s Santa Cruz River, often cited in the arroyo literature, offers a unique opportunity to chronicle the 

arroyo legacy and evaluate its causes. The study presented 

reconstructs both the physical and cultural circumstances of 

channel entrenchment along the Santa Cruz River. Primary 

data include newspaper accounts, notes and plants of General 

Land Office surveys, eyewitness accounts, legal depositions 

and repeat photography. MULTIPLE THREATS

42. Bilby, R.E. 1988. Interactions between aquatic and terrestrial systems. In: Raedeke, K.J., ed. Streamside 

management: Riparian wildlife and forestry interactions. 

Institute of Forest Resources Contribution 59. Seattle, 

WA: University of Washington: 13-30.

Abstract: The interactions between aquatic and terrestrial 

ecosystems must be considered in assessing the potential 

impacts of change in either. Although the type and magnitude 

of the interactions may vary from site to site, the linkages 

between the two systems are still largely responsible for the 

physical, chemical, and biotic characteristics of the riparian 

and aquatic habitats. For example, small streams are more 

severely affected by riparian vegetation than larger ones. 

MULTIPLE THREATS

43. Bisson, P.A.; Rieman, B.E.; Luce, C.; Hessburg, P.F.; 

Lee, D.C.; Kershner, J.L.; Reevfes, G.H.; Gresswell, 

R.E. 2003. Fire and aquatic ecosystems of the western 

U.S.A.: Current knowledge and key questions. Forest 

Ecology and Management. 178: 213–229.

Abstract: This paper synthesizes information from the Fire 

and Aquatic Ecosystems Workshop, which identified concepts 

and tools emerging from current science, explored research 

strategies that will improve understanding, and identified 

management implications. The ultimate goal was to help 

managers identify ecologically sound and socially acceptable 

ways to protect and restore aquatic ecosystems and processes 

that are influenced by fire and its management. In this paper, 

the authors summarize the important points that emerged from 

the workshop and related research. The authors also suggest 

research questions that, when answered, will aid in formulating socially and ecologically acceptable fire management 

policy. They propose a path toward improved understanding 

that involves managers, scientists, and the public. FIRE

44. Bisson, P.A.; Quinn, T.P.; Reeves, G.H.; Gregory, S.V. 

1992. Best management practices, cumulative effects and 

long-term trends in fish abundance in Pacific Northwest 

river systems. In: Naiman, R.J., ed. Watershed management: Balancing sustainability and environmental 

change. New York: Springer-Verlag: 189-225.

Abstract: In this article the authors review the difficulties in 

describing cumulative effects of forest management on fishes 

of the Pacific Northwest. Despite uncertainties in interpreting long-term trends from catch and escapement statistics as 

well as widespread programs of hatchery production, many 

local fish populations are declining. MULTIPLE THREATS

45. Blinn, C.R.; Dahlman, R.A. 1996. Riparian harvesting 

with a soft footprint. In: Laursen, S.B., ed. At the water’s 

edge: The science of riparian forestry. Proceedings of 

the science of riparian forestry conference; 1995 June 

19-20; Duluth, MN. University of Minnesota: 76-81.

Abstract: A variety of approaches can be utilized to leave 

a soft footprint when harvesting within a riparian management zone (RMZ). A selection of planning considerations, 

harvesting strategies, equipment options, and alternatives for 

temporary crossings of streams and areas with weak or wet 

soils are discussed. The specific practices selected for operating in a particular RMZ need to consider the operational 

capabilities and economic constraints that the logger faces. 

FOREST HARVESTING

46. Bock, C.E.; Saab, V.A.; Rich, T.D.; Dobkin, D.S. 1992. 

Effects of livestock grazing on neotropical migratory 

landbirds in western North America. In: Finch, D.M; 

Stangel, P.W., eds. Status and management of neotropical 

migratory birds; 1992 September 21-25; Estes Park, CO . 

Gen. Tech. Rep. RM-229. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain 

Forest and Range Experiment Station: 296-309.

Abstract: Livestock grazing is a widespread and important 

influence on neotropical migratory birds in four major ecosystems in western North America: Grasslands of the Great 

Plains and Southwest, riparian woodlands, Intermountain 

shrubsteppe, and open coniferous forests. The objective of 

this article is to provide a succinct management-oriented 

overview of species-specific avian responses to grazing in 

the aforementioned habitats. GRAZING

47. Boeer, W.J.; Schmidly, D.J. 1977. Terrestrial mammals 

of the riparian corridor in Big Bend National Park. In: 

Johnson, R.R.; Jones, D.A., tech. coords. Importance, 

preservation and management of riparian habitat: A 

symposium; 1977 July 9; Tucson, AZ . Res. Pap. RM43. Fort Collins, CO: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Forest and Range 

Experiment Station: 212-217.
18 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

Abstract: Thirty species of terrestrial mammals inhabit riparian habitats in Big Bend National Park (BBNP), but only 

one species (the beaver) is restricted to these areas. Major 

changes in the vegetation during the past 30 years, involving 

an increase in basal and canopy cover, have resulted in the 

elimination of at least one species from the river corridor as 

well as increased abundance and distribution for two other 

species. Compared to the other major plant communities 

in BBNP, the rodent fauna of the riparian community has 

lower evenness, richness, and diversity indices. Human use 

and trespass livestock grazing are the major impacts acting 

on the natural riparian communities in BBNP. MULTIPLE 

THREATS

48. Boggs, K.; Weaver, T. 1991. Response of riparian shrubs to 

declining water availability. In: Clary, W.P.; McArthur, 

E.D.; Bedunah, D.; Wambolt, C.L., comps. Proceedings 

of the symposium on ecology and management of riparian shrub communities; 1991 May 29-31; Sun Valley, 

ID. Gen. Tech. Rep. INT-309. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain 

Research Station: 48-51.

Abstract: Community dominance, productivity and grazing 

effects were recorded in a cottonwood sere along the Yellowstone River. The sere progressed from seedlings of Great 

Plains cottonwood and sandbar willow, to cottonwood forests 

with a dense shrub understory, and then to grasslands. Total 

shrub canopy cover and biomass rose as sandbar willow matured, declined as they died, rose again as shrubs developed 

under the cottonwood canopy, and declined as grasslands 

dominated. GROUNDWATER DEPLETION

49. Bohn, B.A.; Kershner, J.L. 2002. Establishing aquatic 

restoration priorities using a watershed approach. 

Journal of Environmental Management. 64: 355–363.

Abstract: This article introduces the watershed analysis procedure as an important tool to help restoration practitioners 

identify, prioritize and implement aquatic restoration activities 

at the appropriate ecosystem scale. MULTIPLE THREATS

50. Bohn, C. 1989. Management of winter soil temperatures to 

control streambank erosion. In: Gresswell, R.E.; Barton, 

B.A.; Kershner, J.L. eds. Practical approaches to riparian resource management: An educational workshop; 

1989 May 8-11; Billings, MT. U.S. Department of the 

Interior, Bureau of Land Management: 69-71.

Abstract: Temperature modifications resulting from vegetative cover appear to be sufficient to reduce the number of 

freeze-thaw cycles along the streambank face. Riparian management should be designed to provide sufficient vegetative 

cover over the winter to insulate streambanks and maintain 

soil strength. WATER QUALITY

51. Bohn, C.C.; Buckhouse, J.C. 1985. Some response of 

riparian soils to grazing management in Northeastern 

Oregon. Journal of Range Management. 38: 378-381.

Abstract: Infiltration, sediment production, penetrometer 

penetrability and bulk density were measured on control/

treatment paired plots of several grazing schemes in a 

riparian zone of northeastern Oregon. Treatments were 

in effect over a period of 5 years. Restoration favored the 

hydrologic parameters measured, while deferred rotation 

and season-long grazing did little to enhance, and sometimes 

hindered, hydrologic expression. Late-season grazing in September demonstrated a positive hydrologic response, whereas 

late-season grazing in October was negative—probably due 

to the onset of fall rains and a change in soil moisture conditions. GRAZING

52. Boldt, C.E.; Uresk, D.M.; Severson, K.E. 1978. Riparian 

woodlands in jeopardy on the northern high plains. In: 

Johnson, R.R.; McCormick, J.F., tech. coords. Strategies 

for protection and management of floodplain wetlands 

and other riparian ecosystems. Gen. Tech. Rep. WO12. Washington, DC: U.S. Department of Agriculture, 

Forest Service: 187-189.

Abstract: There is considerable evidence that riparian woodlands are decadent as evidenced by rotten trees with broken 

and snag tops. Some woodlands have been replaced by grasses 

and forbs. Many of these woodlands are in advanced stages 

of deterioration. Small patches of shrubs and trees are found 

in the draw systems. Many of these shrub-tree stands are 

near the end of their life spans, are vulnerable to damage by 

insects, disease, and humans. Other factors that may influence 

long-term changes in these woodlands are alteration of the 

local hydrology, climate change, geology, soils, plant succession, and protection from wildfire. MULTIPLE THREATS

53. Boone, S.G. 1976. Problems of irrigation return flows. 

In: Environmental aspects of irrigation and drainage; 

1976 July 21-23. Ontario, Canada: University of Ottawa: 673-689.

Abstract: There are water quality problems with irrigation 

return flows. The quality of the receiving water is usually 

degraded by irrigation flow or at least modified in quality. 

This paper discusses the significance of the water quality 

problems and what can be done to reduce water pollution, 

especially in the western United States. WATER DIVERSION

54. Borden, F.Y.; Turner, B.J.; Strauss, C.H. 1977. Colorado 

River campsite inventory. In: Proceedings of river 

recreation management and research symposium; 1977 

January 24-27; Minneapolis, MN. Gen. Tech. Rep. 

NC-28. St. Paul, MN: U.S. Department of Agriculture, 

Forest Service, North Central Forest Experiment Station: 226-231.

Abstract: With the influx of river-running recreationists into 

undeveloped sections of rivers, the wilderness aspects of these 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 19

environments may be endangered by overuse. Visitor carrying capacity of a river section for river-running is a function 

of the number of beaches for campsite use, their locations, 

and their individual capacities. The first phase of a project 

to assess the overall carrying capacity of the Grand Canyon 

river-running system was the campsite inventory described 

in this article. RECREATION

55. Borden, T.B. 1978. Cottonwood as a crop in Colorado. In: 

Graul, W.D.; Bissel, S.J., tech. coords. Lowland river 

and stream habitat in Colorado: A Symposium; 1978 

Oct 4-5; Greeley, CO: Wildlife Society and Colorado 

Audubon Council, Colorado Chapter: 114-117.

Abstract: This paper addresses the threats to riparian communities when cottonwood is used as a crop. MULTIPLE 

THREATS

56. Boydstun, C.; Fuller, P.; Williams, J.D. 1995. Nonindigenous fish. In: LaRoe, E.T.; Farris, G.S.; Puckett, C.E.; 

Doran, P.D.; Mac, M.J., eds. Our living resources: A 

report to the nation on the distribution, abundance, and 

health of U.S. plants, animals, and ecosystems. Washington, DC: U.S. Department of the Interior, National 

Biological Service: 431-433.

Abstract: Intentional and unintentional aquatic introductions have enabled nonindigenous fish to become permanent 

residents in the U.S. aquatic system. This article analyzes 

reports of nonindigenous fish introductions with a cut-off 

date of 1800. INVASIVE SPECIES

57. Braasch, S.; Tanner, G.W. 1989. Riparian zone inventory. 

Rangelands. 11(3): 103-106.

Abstract: This paper summarizes two studies that (1) evaluated the capacity of mountain stream channels to resist detachment of bed and bank materials, (2) provided information 

about the capacity of streams to adjust to and recovery from 

potential changes in water flow and/or increases in sediment 

production , and (3) evaluated the successional state and range 

condition of the riparian plant community. These studies 

provided a better understanding of the relationships between 

livestock grazing and riparian zone protection/preservation 

and the enhancement of fish habitat. MULTIPLE THREATS

58. Braatne, J.H.; Rood, S.B.; Goater, L.A.; Blair, C.L. 2008. 

Analyzing the impacts of dams on riparian ecosystems: 

A review of research strategies and their relevance to 

the Snake River through Hells Canyon. Environmental 

Management. 41: 267-281.

Abstract: This article provides an assessment of dams and 

river flow regulation on riparian ecosystems. The authors 

conclude that multiple study approaches are essential to 

provide confident interpretations of ecological impacts 

downstream from dams and propose a comprehensive study 

for Hells Canyon that integrates multiple research strategies. 

DAM CONSTRUCTION

59. Bradley, C.E.; Smith, D.G. 1986. Plains cottonwood recruitment and survival on a prairie meandering river 

floodplain, Milk River, Southern Alberta and Northern 

Montana. Canadian Journal of Botany. 64: 1433-1442.

Abstract: Age, distribution, and density of two populations 

of plains cottonwood (Populus deltoides var. occidetltalis

Rydb.) on the floodplain of the Milk River, southern Alberta 

and northern Montana, were studied in relation to historical 

river hydrology and sedimentation regimes. In Alberta, cottonwood recruitment leading to long-term survival on river 

meander lobes (point bars) correlates with years when daily 

maximum flows during the period of seed dispersal (June 1 

to July 10) attain a stage equal to or greater than the 2-year 

return flood, based on the annual flood series. Such flood 

events, during the seed dispersal period, occur an average 

of once in 5 years. In Montana, on the floodplain for 25 km 

downstream of Fresno Dam, built in 1939, the densities of 

cottonwoods recruited since 1939 are significantly lower than 

on floodplain sites upstream, in Alberta. Results suggest that 

this is due to a marked reduction in flood magnitude and 

frequency, rates of sedimentation and meander migration. 

Based on this study, the prospects for cottonwood survival 

on floodplains downriver from dams in this and other prairie 

river valleys are not encouraging unless management measures are taken to reverse the trend. DAM CONSTRUCTION

60. Breeding, N.A. 1995. Management plan for the Rio Cebolla 

watershed Sandoval County and Rio Arriba County, 

New Mexico. In: Shaw, D.W.; Finch, D.M., tech. coords. 

Desired future conditions for southwestern riparian ecosystems: Bringing interests and concerns together. Gen. 

Tech. Rep. RM-272. Fort Collins, CO: U.S. Department 

of Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 346-350.

Abstract: This paper discusses a proposed watershed management plan to remediate water quality problems of the Rio 

Cebolla watershed in northern New Mexico. These issues 

include eutrophication of Fenton Lake Reservoir, riparian 

damage and heavy sediment in the river. As a result, fish 

productivity and fishing is poor and scenic enjoyment is 

spoiled. WATER QUALITY

61. Briggs, M.K. 1992. An evaluation of riparian revegetation 

efforts in Arizona. Master Thesis. Tucson: University 

of Arizona. 229 p.

Abstract: This thesis evaluated 25 riparian revegetation 

projects and two alternative mitigation projects in Arizona. 

Riparian revegetation is limited in its ability to improve degraded riparian ecosystems and is most effective when the 

causes of site degradation are addressed. Interrupting natural 

river flow, a drop in the water table, intense competition 

from animals and plants, and unstable substrate were cited as 

probable causes of site deterioration. MULTIPLE THREATS
20 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

62. Briggs, M.K. 1996. Riparian ecosystem recovery in arid 

lands. Tucson: University of Arizona Press. 160 p.

Abstract: The book presents a review of watershed characteristics and an examination of drainage systems, then 

proceeds to a determination of the causes of riparian decline. 

It describes the factors that have a significant effect on the 

results of riparian rehabilitation and offers case studies that 

demonstrate how revegetation has been used both effectively 

and ineffectively. It also discusses strategies other than revegetation that may be effective. MULTIPLE THREATS

63. Briggs, M.K.; Roundy, B.A.; Shaw, W.W. 1994. Trial and 

error: Assessing the effectiveness of riparian revegetation in Arizona. Restoration and Management Notes. 

12: 160-167.

Abstract: Improvement of degraded riparian ecosystems by 

revegetation has some limitations. Riparian revegetation is 

most effectively used in areas where artificially planted vegetation survives without being obscured by natural regeneration 

of the same species that were planted. Addressing the causes 

of site degradation is the most important factor in successful 

riparian revegetation. MULTIPLE THREATS

64. Brinson, M.M.; Swift, B.L; Plantico, R.C.; Barclay, J.S. 

1981. Riparian ecosystems: Their ecology and status. 

Report FWS/0BS-81/17. Kearneysville, WV: U.S. 

Department of the Interior, Fish and Wildlife Service, 

Biological Services Program. 155 p.

Abstract: This paper documents and interprets the information that is available on riparian ecosystems so that the 

consequences of their alteration and deterioration can be 

assessed at a national level. The common functional properties of these ecosystems and their attractiveness to wildlife 

make it possible to address riparian ecosystems as discrete 

and manageable entities. MULTIPLE THREATS

65. Brinson, M.M.; Malvárez, A.I. 2002. Temperate freshwater wetlands: types, status, and threats. Environmental 

Conservation. 29(2): 115-133.

Abstract: This review examines the status of temperate-zone 

freshwater wetlands and makes projections of how changes 

over the 2025 time horizon might affect their biodiversity. 

Information from the recent technical literature, general accounts in books, and some first-hand experience provided 

the basis for describing major wetland types, their status and 

major threats. Loss of biodiversity is a consequence both of 

a reduction in area and deterioration in condition. Factors 

responsible for losses and degradation include diversions and 

damming of river flows, disconnecting floodplain wetlands 

from flood flows, eutrophication, contamination, grazing, 

harvests of plants and animals, global warming, invasions 

of exotics, and the practices of filling, dyking, and draining.

MULTIPLE THREATS

66. Brock, J. H. 1994. Tamarix spp. (saltcedar), an invasive 

exotic woody plant in arid and semi-arid riparian habitats 

of western USA. In: de Waal, L.C.; Child, L.E.; Wade, 

P.M.; Brock, J.H., eds. Ecology and management of 

invasive riverside plants. Chichester, NY: John Wiley 

and Sons Ltd.: 27-44.

Abstract: This chapter chronicles the introduction and effects 

of saltcedar on riparian systems of the arid and semi-arid west. 

The ecology of this invasive species is discussed as well as 

various management techniques used to curb its growth and 

prevalence. INVASIVE SPECIES

67. Brode, J.M.; Bury, R.B. 1984. The importance of riparian systems to amphibians and reptiles. In: Warner, 

R.E.; Hendrix, K.M., eds. California riparian systems: 

Ecology, conservation, and productive management. 

Berkeley, CA: University of California Press: 30-36.

Abstract: California has about 120 native herpetofauna 

species. Riparian systems provide habitat for 83% of the 

amphibian and 40% of the reptile species. Harvesting timber 

and creating reservoirs are detrimental to amphibians and 

reptiles in the zone of influence of such activities. These 

activities have their greatest effects upon reptiles and amphibians whose entire life histories occur in the riparian zone. 

MULTIPLE THREATS

68. Brookshire, D.S.; McKee, M.; Schmidt, C. 1996. Endangered species in riparian systems of the American 

West. In: Shaw, D.W.; Finch, D.M., tech. cords. Desired 

future conditions for southwestern riparian ecosystems: 

Bringing interests and concerns together. Gen. Tech. 

Rep. RM-272. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station : 238-241.

Abstract: This paper examines the economic impact of critical habitat designation for three fish species endemic to the 

Virgin River of Arizona, Nevada, and Utah: the woundfin, 

the Virgin River chub, and the Virgin River spinedace. The 

authors state that the impact of critical habitat designation 

is very small when viewed in the context of the regional 

economy. AGRICULTURE, URBANIZATION

69. Brothers, T.S. 1984. Historical vegetation change in the 

Owens River riparian woodlands. In: Warner, R.E.; 

Hendrix, K.M., eds. California riparian systems: 

Ecology, conservation, and productive management. 

Berkeley, CA: University of California Press: 75-84.

Abstract: This study evaluates human-caused vegetation 

change in the riparian woodland of Owens River. The greatest change occurred below the intake of the Los Angeles 

Aqueduct, where drying of the channel has eliminated most 

native riparian cover and allowed invasion by saltcedar and 

Russian olive. Fire, water management, and other factors 

may have reduced tree cover above the aqueduct intake and 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 21

encouraged proliferation of weedy native shrubs. The scarcity 

of tree seedling suggests that one or more of these factors 

continue to inhibit tress regeneration. MULTIPLE THREATS

70. Brown, B.T.; Johnson, R.R. 1985. Glen Canyon Dam, 

fluctuating water levels, and riparian breeding birds: 

The need for management compromise on the Colorado 

River in the Grand Canyon. In: Johnson, R.R.; Ziebell, 

C.D.; Patton, D.R.; Ffolliott, P.F.; Hamre, R.H., tech. 

coords. Riparian ecosystems and their management: 

reconciling conflicting uses. First North American riparian conference; 1985 April 16-18; Tucson, AZ. Gen. 

Tech. Rep. RM-120. Fort Collins, CO: U.S. Department 

of Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 76-80.

Abstract: Large water releases from Glen Canyon Dam in 

May and June are harmful to riparian breeding birds along 

the Colorado River in the Grand Canyon. Nest inundation can 

be avoided by releasing surplus water at times other than the 

breeding season. Habitat loss is the most serious long-term 

threat to riparian birds. WATER DIVERSION

71. Brown, D.E.; Lowe, C.H.; Hausler, J.F. 1977. Southwestern riparian communities: Their biotic importance and 

management in Arizona. In: Johnson, R.R.; Jones, D.A. 

tech. coords. Importance, preservation and management 

of riparian habitat: A symposium. 1977 July 9; Tucson, 

AZ. Res. Pap. RM-43. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain 

Forest and Range Experiment Station: 201-211.

Abstract: The various riparian communities occurring in 

Arizona and the Southwest are described and their biotic 

importance discussed. Recommendations are made concerning the management of streamside environments and their 

watersheds. These include recommendations pertaining to 

the classification and inventory of riparian habitats; the determination of limiting factors for key riparian species; the 

establishment of study areas; the regulation and elimination 

of livestock grazing; the greater consideration of streamside 

vegetation in authorizing water management projects; and 

the more conservation use of our watersheds. MULTIPLE 

THREATS

72. Brown, H.T. 1984. A case study of a salinity control 

program, Uinta Basin, Utah. In: French, R.H., ed. 

Salinity in watercourses and reservoirs: Proceedings 

of the 1983 international symposium on state-of-theart control of salinity; July 13-15; Salt Lake City, UT. 

Boston: Butterworth Publishers: 275-284.

Abstract: This paper discusses the problems and solutions 

related to the salt contribution to the Colorado River due to 

irrigation. These include the water supply and use, soils, and 

geologic formations. WATER QUALITY

73. Bryant, L.D. 1982. Response of livestock to riparian zone 

exclusion fencing. Journal of Range Management. 35: 

781-785.

Abstract: In this study the major portion of a streamside riparian zone was excluded by fencing. Use by cows with calves 

and by yearlings was evaluated on the remaining portion of 

the riparian and upland zones during the summer grazing 

season. Regardless of aspect, both classes of livestock generally selected the riparian zone over the uplands throughout 

most of the summer grazing season. Both classes of livestock 

reversed their selection in favor of upland vegetation in the 

latter part of the season. Slopes less than 35% were preferred 

throughout the grazing season. Cows were more selective in 

use of certain plant communities than yearlings and, contrary 

to usual findings, distributed themselves over the range better than yearlings. Neither salt placement nor alternate water 

location away from the riparian zone influenced livestock 

distribution appreciably. GRAZING

74. Bryant, L.D. 1985. Livestock management in the riparian 

ecosystem. In: Johnson, R.R.; Ziebell, C.D.; Patton, D.R.; 

Ffolliott, P.F.; Hamre, R.H., tech. coords. Riparian ecosystems and their management: Reconciling conflicting uses. 

First North American riparian conference; 1985 April 16-18; 

Tucson, AZ. Gen. Tech. Rep. RM-120. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain 

Forest and Range Experiment Station: 285-289.

Abstract: Intensive, long-term livestock grazing has occurred 

along most streams in the western United States. Although 

most livestock grazing on public lands is now under some 

form of management, many riparian areas are below “good” 

in ecological condition, with forage production considerably 

below. Eight years of research at Meadow Creek, Starkey 

Experiment Forest and Range, Wallowa-Whitman National 

Forest, in northwestern Oregon, indicates that herbage production was increased 1- to 4-fold through timing and intensity 

of grazing. Rest-rotation, deferred rotation, and season-long 

grazing systems were tested. Although there were no statistically different changes in plant composition, the production of 

both graminoids and forbs increased dramatically. GRAZING

75. Buckhouse, J. 1991. Grazing practice relationships: Predicting riparian vegetation response from stream systems. 

In: Bedell, T., ed. Watershed management guide for the 

interior Northwest. Oregon State University Extension 

Service. Corvallis, OR: 47-52.

Abstract: Grazing management can be either helpful or detrimental to riparian systems. The natural stress of a stream 

system (prevailing climate, gradient, soil, rock, water flow, 

etc.) ranges from stable to unstable. Management-induced 

stress (grazing intensity, season of use, logging practices, 

roading systems, etc.) can range from minimal to dramatic.

GRAZING
22 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

76. Bull, W.E. 1997. Discontinuous ephemeral streams. 

Geomorphology. 19: 227-276.

Abstract: Initiation of arroyo cutting may be too complex to 

be attributed to a single cause such as change in mean annual 

precipitation or grazing by livestock, but is most likely associated with a decrease in density of protective plant cover 

on hillsides and along valley floors. Relatively larger unit 

stream power makes downstream reaches more susceptible 

to initial entrenchment during floods than headwater reaches, 

and favors persistent arroyos. Entrenchment continues until 

an equilibrium longitudinal profile is briefly attained. Then, 

channel widening occurs: streambanks are undercut, and 

aggradation begins. This paper attempts to answer a variety 

of questions related to discontinuous ephemeral streams. 

However, the emphasis in this paper departs from that of 

most past literature in two ways. First, discussions include 

the hydrology of aggrading reaches, as well as degrading 

reaches. Second, conceptual models, including the base 

level of erosion, threshold of critical power, and time lags of 

response are used to evaluate the characteristics of discontinuous ephemeral streams. The author concludes that changes 

in vegetation density on hillslopes and along valley floors, 

either as a result of short-term climatic change or because of 

the actions of humans, profoundly influences the responses 

of discontinuous ephemeral streams. MULTIPLE THREATS

77. Bunn, S.E.; Arthington, A.H. 2002. Basic principles 

and ecological consequences of altered flow regimes 

for aquatic biodiversity. Environmental Management. 

30(4): 492-507.

Abstract: This literature review is focused around four key 

principles to highlight the important mechanisms that link 

hydrology and aquatic biodiversity and to illustrate the consequent impacts of altered flow regimes: (1) flow is a major 

determinant of physical habitat in streams; (2) aquatic species 

have evolved life history strategies primarily in direct response 

to the natural flow regimes; (3) maintenance of natural patterns of longitudinal and lateral connectivity is essential to 

the viability of populations of many riverine species; and 

(4) the invasion and success of exotic and introduced species 

in rivers is facilitated by the alteration of flow regimes. The 

impacts of flow change are manifest across broad taxonomic 

groups including riverine plants, invertebrates, and fish.

MULTIPLE THREATS

78. Bunn, S.E.; Davies, P.M.; Mosisch, T.D. 1999. Ecosystem 

measures of river health and their response to riparian 

and catchment degradation. Freshwater Biology. 41: 

333-345.

Abstract: This paper assesses stream ecosystem response 

to catchment disturbance, particularly to the loss of riparian vegetation by quantifying the sources and fate of energy 

and nutrients. Benthic gross primary production (GPP) and 

respiration (R24) provided measures of the amount of organic 

carbon produced and consumed within the system, while 

stable isotope analysis was used to trace the fate of terrestrial 

and instream sources of organic matter in the aquatic food 

web. A decline in the health of forest streams was observed 

when GPP exceeded R24, especially when instream primary 

producers switched from palatable unicellular algae to prolific 

filamentous green algae and macrophytes. Accumulation of 

these plants has led to changes in channel morphology, loss 

of aquatic habitat, and a decline in water quality. MULTIPLE 

THREATS

79. Burke, M.; Jorde, K.; Buffington, J.M. 2009. Application 

of a hierarchical framework for assessing environmental 

impacts of dam operation: Changes in streamflow, bed 

mobility and recruitment of riparian trees in a western 

North American river. Journal of Environmental Management. 90: S224-S236.

Abstract: This case study demonstrates how a process-based, 

hierarchical framework can be used for quantifying environmental impacts of dam operations over space and time, and 

provides an approach for evaluating alternative management 

strategies. DAM CONSTRUCTION

80. Burkham, D.E. 1976. Hydraulic effects of changes in bottomland vegetation on three major floods, Gila River 

in Southeastern Arizona. Professional Paper 655-J. 

Washington, DC: U.S. Geologic Survey. 14 p.

Abstract: The main purpose of this report is to describe 

the apparent differences in hydraulic characteristics of the 

Gila River during three major floods owing to changes in 

bottom-land vegetation. The types of change in vegetation 

is the replacement of salt-cedar and mesquite trees with 

grass, which is likely to cause changes in rates of erosion 

and deposition, in channel width, depth, sinuosity, gradient, 

roughness, and even channel location. FLOODS

81. Burns, J.W. 1978. Planning for riparian vegetation 

management on the Sacramento River, California. In: 

Johnson, R.R.; McCormick, J.F., tech. coords. Strategies 

for protection and management of floodplain wetlands 

and other riparian ecosystems. Gen. Tech. Rep. WO12. Washington, DC: U.S. Department of Agriculture, 

Forest Service: 178-183.

Abstract: Natural resource values of the Sacramento River 

are being threatened by agricultural encroachment, flood 

control, erosion control and water development projects. 

The methods for preserving riparian vegetation that have 

been explored include zoning, modifying flood and erosion 

control construction and maintenance practices, regulating 

timber harvesting, mitigating losses, acquiring land, developing a resource atlas to guide future planning, and developing 

a waterways management plant for the river. MULTIPLE 

THREATS
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 23

82. Bury, R.B.; Corn, P.S. 1988. Response of aquatic and 

streamside amphibians to timber harvest: A review. In: 

Raedeke, K.J., ed. Streamside management: Riparian 

wildlife and forestry interactions. Contribution No. 

59. Seattle, WA: University of Washington, Institute 

of Forest Resources: 165-181.

Abstract: Stream-dwelling amphibians, which can be the 

dominant vertebrates of small streams in forests of the PacificNorthwest, are prototypic riparian organisms. Impacts of 

timber harvest vary among species, physical habitats, and regions 

of the Pacific Northwest. Populations of giant salamanders increased following clear cutting in the Oregon Cascades, while 

in the Oregon Coast Range long-term effects of logging were 

negative and severe for all species. FOREST HARVESTING

83. Busby, F.E. 1978. Stream and stream ecosystems, livestock 

grazing and multiple-use management. In: Cope, O.B., 

ed. Proceedings of the forum—grazing and riparian/

stream ecosystems; 1978 November 3-4; Denver, CO. 

Arlington, VA: Trout Unlimited: 6-12.

Abstract: This paper emphasizes stream and riparian ecosystems and their use as trout habitat. The problem generally 

attributed to the relationship between these ecosystems and 

livestock grazing include (1) vegetation deterioration in the 

riparian zone near the streams, (2) stream bank destruction, 

(3) shallower and wider streams, (4) higher stream water 

temperature, (5) sediment-covered stream bottoms, (6) loss 

of trout spawning beds, and (7) loss of trout. GRAZING

84. Busch, D.C.; Smith, S.D. 1995. Mechanisms associated 

with decline of woody species in riparian ecosystems 

of the southwestern U.S. Ecological Monographs. 

65(3): 347-371.

Abstract: This paper evaluates the interactions of dominant 

woody riparian taxa of the lower Colorado River systems 

under two primary hypothesis: (1) that hydrologic variation 

has significant effects on riparian plant community structure 

and function; and (2) that varying salinity in floodplain 

environments also affects these attributes. The persistence 

of Salix, but not Populus, on the Colorado River appears to 

be due to greater water and salinity stress tolerance in Salix

than in Populus. MULTIPLE THREATS

85. Busch, D.E.; Scott, M.L. 1995. Western riparian ecosystems. In: LaRoe, E.T.; Farris, G.S.; Puckett, C.E.; Doran, 

P.D.; Mac, M.J., eds. Our living resources: A report to 

the nation on the distribution, abundance, and health 

of U.S. plants, animals, and ecosystems. Washington, 

DC: U.S. Department of the Interior, National Biological Service: 286-290.

Abstract: This article contrasts the roles played by natural 

and human-induced disturbances in structuring western riparian ecosystems and draws data from the lower Colorado 

and upper Missouri. Decline in riparian forest dominated 

by cottonwood and willow have been attributed to change 

in the physical environment and to the extensive invasion of 

tamarisk. This article also focuses on how water and landuse management may threaten valuable ecological resources. 

MULTIPLE THREATS

86. Busch, D.E.; Smith, S.D. 1991. Fire in a riparian shrub 

community: Postburn water relations in the tamarixsalix association along the lower Colorado River. In: 

Clary, W.P.; McArthur, E.D.; Bedunah, D.; Wambolt, 

C.L., comps. Proceedings of the symposium on ecology 

and management of riparian shrub communities; 1991 

May 29-31; Sun Valley, ID. Gen. Tech. Rep. INT-309. 

Ogden, UT: U.S. Department of Agriculture, Forest 

Service, Intermountain Research Station: 52-55.

Abstract: Higher potentials in recovering burned salt-cedar 

relative to unburned plants and the opposite situation in willow provide evidence that postfire water stress is reduced in 

the former but not the latter. Similarily, diurnal patterns of 

stomatal conductance in these taxa are consistent with the 

existence of more vigor in burned salt-cedar than willow. 

Plots of water potential and transpiration demonstrate that 

hydraulic efficiencies may contribute to differences in fire 

recovery. FIRE

87. Campbell, C.J.; Green, W. 1968. Perpetual succession of 

stream-channel vegetation in a semiarid region. Journal 

of the Arizona Academy of Science. 5: 86-97.

Abstract: In this paper the authors separate riparian from 

the proposed term “pseudoriparian,” thus making riparian of 

an obligate nature and pseudoriparian facultative. Pseudoriparian would apply to woody plants capable of completing 

their life cycle in relatively xeric or mesic sites, but which 

achieve maximum size and density when additional subsurface 

moisture is available. Special management problems created 

by exotic species are also discussed. INVASIVE SPECIES

88. Cannon, R.W.; Knopf, F.L. 1984. Species composition of 

a willow community relative to seasonal grazing histories in Colorado. Southwestern Naturalist. 29: 234-237.

Abstract: This paper describes the consequences of longterm grazing upon the species composition of a shrub willow 

community in Colorado. GRAZING

89. Capelli, M.H.; Stanley, S.J. 1984. Preserving riparian 

vegetation along California’s south-central coast. In: 

Warner, R.E.; Hendrix, K.M., eds. California riparian 

systems: Ecology, conservation, and productive management. Berkeley: University of California Press: 673-686.

Abstract: California’s south central coast contains over 400 

km of riparian vegetation within the Coastal Zone, concentrated principally in narrow corridors bordering short coastal 

streams. A great deal of this vegetation has been disturbed 

or destroyed by urban, agricultural, and related flood control 

activities. MULTIPLE THREATS
24 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

90. Carothers, S.W.; Brown, B.T. 1991. The Colorado River 

through Grand Canyon: Natural history and human 

change. Tucson: University of Arizona Press: 235 p.

Abstract: This book chronicles change in the natural world 

of the Colorado River as it flows through the Grand Canyon. 

The authors discuss pre-dam conditions and the effects damming of the river has had on natural conditions and processes. 

They describe how these natural systems have adjusted to 

and persisted through human induced environmental alterations. The authors rely on a large body of research to detail 

current conditions, management concerns, and restoration/

rehabilitation options. Their discussion on the effects of 

regulated flow due to damming on the riparian areas covers 

numerous management issues such as: vegetation increases, 

invasive species abundance, and sediment deposition rates. 

DAM CONSTRUCTION

91. Carothers, S.W.; Johnson, R.R. 1981. Status of the Colorado River ecosystem in the Grand Canyon National 

Park and Glen Canyon National Recreation Area. In: 

Adams, V.D.; Lamarra, V.A., eds. Aquatic resources 

management of the Colorado River ecosystem; Proceedings of the 1981 symposium on the aquatic resources 

management of the Colorado River ecosystem; 1981 

November 16-18; Las Vegas, NV. Ann Arbor Science 

Publishers: 139-160.

Abstract: This report summarizes the known ecological 

changes that have occurred within the aquatic and riparian 

ecosystems of the Colorado River Glen and Grand Canyons 

that result from structural control of the river and the more 

recent recreational use taking place. In addition, it discusses 

the issues and concerns that influence the capability of the 

National Park Service to carry out its mandate to maintain 

these administrative areas for the good of present and future 

generations. MULTIPLE THREATS

92. Carothers, S.W.; Mills, G.S.; Johnson, R.R. 1990. The creation and restoration of riparian habitat in southwestern 

arid and semi-arid regions. In: Kusler, J.A.; Kentula, 

M.E., eds. Wetland creation and restoration: The status 

of the science. Washington, DC: Island Press: 351-366.

Abstract: This paper discusses the creation and restoration of 

riparian habitats in Southwestern arid and semi-arid regions. 

In most cases, creation and restoration projects have involved 

the planting of vegetation and not the creation of conditions 

suitable for the natural regeneration of riparian habitats. 

Important considerations for riparian creation or restoration 

projects include the elimination or control of the threats to the 

ecosystem, which include: soil salinity and texture, amount 

and frequency of irrigation, protection from rodent and rabbit predation, elimination of competing herbaceous weeds, 

protection from vandalism, off-road vehicles, and livestock. 

MULTIPLE THREATS

93. Case, R.L. 1995. Ecology of riparian ecosystems of 

Northeast Oregon: Shrub recovery at Meadow Creek 

and the structure and biomass of headwater Upper 

Grande Ronde ecosystems. Master’s Thesis. Corvallis, 

OR: Oregon State University. 137 p.

Abstract: This thesis documents late 20th century headwater riparian structure and biomass in the Upper Rio Grande 

Ronde Basin and provides an ecological perspective related 

to riparian restoration and management. Further, the response 

of riparian hardwood species to the termination of livestock 

and wild ungulate grazing is quantified. GRAZING

94. Chambers, J.C. 2008a. Climate change and the Great 

Basin. In: Chambers, J.C.; Devoe, N.; Evenden, A., 

eds. Collaborative management and research in the 

Great Basin—examining the issues and developing a 

framework for action. Gen. Tech. Rep. RMRS-GTR-204. 

Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 29-32.

Abstract: This paper provides a short overview of past and 

projected climate change for the globe and for the Great Basin 

region. CLIMATE CHANGE

95. Chambers, J.C. 2008b. Invasive plant species and the 

Great Basin. In: Chambers, J.C.; Devoe, N.; Evenden, 

A., eds. Collaborative management and research in the 

Great Basin—examining the issues and developing a 

framework for action. Gen. Tech. Rep. RMRS-GTR-204. 

Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 38-41.

Abstract: This paper provides a short overview of how invasive plant species have affected the Great Basin and what 

the consequences are for native ecosystems and the services 

they provide. INVASIVE SPECIES

96. Chambers, J.C. 2008c. Water resources and the Great 

Basin. In: Chambers, J.C.; Devoe, N.; Evenden, A., 

eds. Collaborative management and research in the 

Great Basin—examining the issues and developing a 

framework for action. Gen. Tech. Rep. RMRS-GTR-204. 

Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 20-23.

Abstract: This paper provides a short overview of the key 

issues affecting the water resources in the Great Basin region. 

MULTIPLE THREATS

97. Chambers, J.C.; Pellant, M. 2008. Climate change impacts on northwestern and intermountain United States 

rangelands. Rangelands. 30(3): 29-33.

Abstract: This paper provides a short overview of the projected climate change and the resulting consequences for the 

Northwestern and Intermountain U.S. rangelands, including 

their riparian ecosystems. CLIMATE CHANGE
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 25

98. Chaney, E.; Elmore, W.; Platts, W.S. 1990. Livestock 

grazing on western riparian areas. Eagle, ID: Northwest 

Resource Information Center. 45 p.

Abstract: This document is aimed at the broad and growing audience of people interested in improved management 

of livestock grazing on western riparian areas and adjacent 

uplands. Its purpose is to provide general insight into the 

problems and opportunities. GRAZING

99. Chaney, E.; Elmore, W.; Platts, W.S. 1993. Managing 

change—livestock grazing on western riparian areas. 

Eagle, ID: Northwest Resource Information Center. 31 p.

Abstract: This document is designed to foster broader 

understanding of how improved grazing management on 

western riparian areas can enhance water quality and overall 

productivity of rangeland watersheds. GRAZING, WATER 

QUALITY

100. Chen, H.; Qualls, R.G.; Blank, R.R. 2005. Effect of soil 

flooding on photosynthesis, carbohydrate partitioning 

and nutrient uptake in the invasive exotic Lepidium 

latifolium. Aquatic Botany. 82: 250–268.

Abstract:Lepidium latifolium L. is an invasive exotic crucifer 

that has spread explosively in wetlands and riparian areas of 

the western United States. To understand the ecophysiological 

characteristics of L. latifolium that affect its ability to invade 

riparian areas and wetlands, this study examined photosynthesis, chlorophyll concentration, carbohydrate partitioning and 

nutrient uptake in L. latifolium in response to soil flooding. 

The results suggested that the maintenance of relatively high 

photosynthesis and the accumulation of soluble sugar in roots 

of flooded plants are important adaptations for this species in 

flooded environments. Despite a reduction in photosynthesis 

and disruption in nutrient and photosynthate allocation in 

response to flooding, L. latifolium was able to survive 50 

days of flooding stress. Overall, L. latifolium performed like 

a facultative hydrophyte species under flooding. INVASIVE 

SPECIES, FLOODS

101. Chischilly, S. 1993. The San Juan River. In: Tellman, 

B.; Cortner, H.J.; Wallace, M.G.; DeBano, L.F.; Hamre, 

R.H., tech. coords. Riparian management: Common 

threads and shared interests; A western regional conference on river management strategies; 1993 Feb 4-6; 

Albuquerque, NM. Gen. Tech. Rep. RM-226. Fort 

Collins, CO: U.S. Department of Agriculture, Forest 

Service, Rocky Mountain Forest and Range Experiment 

Station: 323-327.

Abstract: This paper describes the San Juan River, its watershed, riparian vegetation, and the threats to the river, which 

include river alteration caused by saltcedar and Russian-olive. 

INVASIVE SPECIES

102. Clark County Board of Commissioners. 1978. Clark 

County 208 water quality management plan. Clark 

County, NV. Las Vegas, NV: Clark County Sanitation 

District. 188 p.

Abstract: The draft Clark County 208 Water Quality Management Plan presents the objectives, policies, and programs 

for managing water quality in the county. The plan addresses 

municipal wastewater treatment, ground water management, 

storm water programs, Las Vegas Wash, agriculture diffuse 

sources, and water quality standards revisions. An environmental assessment of the proposed plan is also included. 

WATER QUALITY

103. Clary, W.P. 1995. Vegetation and soil responses to grazing simulation on riparian meadows. Journal of Range 

Management. 48: 18-25.

Abstract: Riparian areas have not responded consistently to 

grazing systems, suggesting that more knowledge is needed 

to explain how different areas respond to specific stresses. 

Several studies were conducted to determine herbaceous 

plant response to simulated grazing on riparian areas. Results 

suggest that many of the land management agency riparian 

guidelines would maintain biomass productivity in these 

sedge-dominated communities. GRAZING

104. Clary, W.P. 1999. Stream channel and vegetation responses to late spring cattle grazing. Journal of Range 

Management. 52: 218-227.

Abstract: A 10-year riparian grazing study was conducted 

on a cold, mountain meadow riparian system in central Idaho 

in response to cattle grazing-salmonid fisheries conflicts. 

Six pastures were established along Stanley Creek to study 

the effects on riparian habitat of no grazing, light grazing, 

and medium grazing during late June. Stream channels narrowed, stream width-depth ratios were reduced, and channel 

bottom embeddedness decreased under all three grazing 

treatments as the area responded to changes from heavier 

historic grazing use. Streambank stability increased and 

streamside willow communities increased in both height and 

cover under all treatments. Plant species richness increased 

on both streamside and dry meadow areas during the years 

of grazing and moderate drought. Many improvements were 

similar under all three treatments indicating these riparian 

habitats are compatible with light to medium late spring use 

by cattle. GRAZING

105. Clary, W.P.; Medin, D.E. 1991. Vegetation, breeding 

bird, and small mammal biomass in two high-elevation 

sagebrush riparian habitats. In: Clary, W.P.; McArthur, 

E.D.; Bedunah, D.; Wambolt, C.L., comps. Proceedings 

of the symposium on ecology and management of riparian shrub communities; 1991 May 29-31; Sun Valley, ID. 

Gen. Tech. Rep. INT-309. Ogden, UT: U.S. Department 

of Agriculture, Forest Service, Intermountain Research 

Station: 100-110.
26 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

Abstract: Two riparian areas, one in Nevada (Deer Creek) and 

one in Idaho (Summit Creek), were compared on the basis of 

vegetation, breeding bird, and small mammal characteristics. 

The objectives of the study were to (1) investigate similarities and dissimilarities of riparian areas otherwise alike in a 

number of environmental conditions, and (2) examine their 

response to grazing stress. GRAZING

106. Clary, W.P.; Booth, G.D. 1993. Early season utilization of 

mountain meadow riparian pastures. Journal of Range 

Management. 46: 493-497.

Abstract: In the Western United States, the greatest impact 

on small stream riparian areas often has been from grazing 

by domestic livestock. This is particularly true for riparian 

areas within arid or semiarid rangelands. In 1987 a grazing 

study was initiated on Stanley Creek located within the Sawtooth National Recreation Area, Sawtooth National Forest, 

in central Idaho. The general objectives were to determine 

vegetation, wildlife, fishery, and stream channel responses 

to grazing management. Observations suggest spring grazing 

of riparian areas is a good management strategy because of 

a reduced tendency for cattle to concentrate along streams 

during that season. In this study, June cattle distribution was 

examined within four experimental pastures located along 

Stanley Creek. Two pastures were grazed at a light stocking 

rate and two pastures were grazed at a medium stocking rate. 

Utilization of riparian plant communities during this early 

summer period had no relationship to the amount of plant 

moisture content, but was negatively associated with surface 

soil moisture. GRAZING

107. Clary, W.P.; Kinney, J.W. 2002. Streambank and vegetation response to simulated cattle grazing. Wetlands. 

22(1): 139–148.

Abstract: Simulated grazing techniques were used to 

investigate livestock impacts on structural and vegetation 

characteristics of streambanks in central Idaho, U.S.A. The 

treatments, continued over 2 years, consisted of no grazing, 

simulated moderate early summer grazing, simulated moderate mid-summer grazing, and simulated heavy season-long 

grazing. Ten months after the last treatment application, the 

average spring foliage growth was 20–43% lower on the 

moderate treatment plots and 51–87% lower on the heavy 

season-long treatment plots than on the untreated control 

plots. GRAZING

108. Clary, W.P.; Kruse, W.H. 2004. Chapter 11: Livestock 

grazing in riparian areas: Environmental impacts, 

management practices and management implications. 

In: Baker, M.B., Jr.; Ffolliott, P.F.; DeBano, L.F.; Neary, 

D.G., eds. 2003. Hydrology, ecology and management 

of riparian areas in the southwestern United States. 

Boca Raton: Lewis Publishers: 237-258.

Abstract: This chapter examines the impacts of grazing in 

Southwest riparian areas since Spanish introduction of cattle 

in the 1500s. In the early 20th Century, major environmental 

damage occurred because of excessive grazing with little or 

no management. Current grazing management is aimed at 

balancing cattle grazing with other impacts from agriculture, 

mining, and recreation. GRAZING

109. Cleverly, J.R.; Smith, S.D.; Sala, A.; Devitt, J.R. 1997. 

Invasive capacity of Tamarix ramosissima in a Mojave 

Desert floodplain: the role of drought. Oecologia. 111: 

12-18.

Abstract: Tamarix ramosissima is a woody phreatophyte 

that has invaded thousands of hectares of floodplain habitat 

in the southwestern United States. This study examined the 

response of gas exchange and stem sap flow of Tamarix and 

three co-occurring native phreatophytes (Pluchea sericea, 

Prosopis pubescens, and Salix exigua) to drought conditions 

in an early successional floodplain community in the Mojave 

Desert of southern Nevada. In an analysis of a size/age series 

of each species across the whole floodplain (both mature 

and successional stands), stem growth rate was lowest for 

Tamarix. However, along the same successional chronosequence, Tamarix came to dominate the 50+ year old stands 

with dense thickets of high stem density. This analysis suggests that the invasive Tamarix is the most drought tolerant 

of the four species, whereas Salix transpires the most water 

per unit leaf surface area and is the least tolerant of seasonal 

water stress. Therefore, Salix appears to be well adapted to 

early successional communities. However, as flood-plains in 

this arid region become more desiccated with age, Tamarix

assumes greater dominance due to its superior drought tolerance relative to native phreatophytes and its ability to produce 

high density stands and high leaf area.

INVASIVE SPECIES, DROUGHT

110. Clifton, C. 1989. Effects of vegetation and land use on 

channel morphology. In: Gresswell, R.E.; Barton, B.A.; 

Kershner, J.L., eds. Practical approaches to riparian 

resource management: An educational workshop; 1989 

May 8-11; Billings MT. U.S. Department of the Interior, 

Bureau of Land Management: 121-129.

Abstract: Spatial and temporal morphologic variability 

in mountain streams may be attributed to local prevailing 

conditions. Morphologically distinct reaches of Wickiup 

Creek, in the Blue Mountains of central Oregon, result from 

differences in the composition and structure of streamside 

vegetation, physiography, and land use. Comparisons of 

grazed and ungrazed meadow reaches and a forested reach 

loaded with large organic debris reveal specific differences 

related to the local environmental setting. Over a 50-year 

period without grazing, a 94% reduction in channel cross 

section area occurred. GRAZING
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 27

111. Cohan, D.R.; Anderson, B.W.; Ohmart, R.D. 1978. Avian 

population responses to salt cedar along the lower 

Colorado River. In: Johnson, R.R.; McCormick, J.F., 

tech. coords. Strategies for protection and management 

of floodplain wetlands and other riparian ecosystems. 

Gen. Tech. Rep. WO-12. Washington, DC: U.S. Department of Agriculture, Forest Service: 371-382.

Abstract: Avian population responses to saltcedar were 

studied seasonally for 3 years along the lower Colorado River. 

Bird densities and diversities were examined in saltcedar 

and three additional types of riparian vegetation, all similar 

horizontal and vertical configurations. Significantly fewer 

insectivores used saltcedar than would be predicted on the 

basis of insect biomass. Avoidance of saltcedar by insectivores 

may be related to the sticky exudates, which may damage 

the plumage. Frugivores were absent from saltcedar because 

of the near total absence of available fruits and berries. INVASIVE SPECIES

112. Colborn, T.; Thayer, K. 2000. Aquatic ecosystems: 

Harbingers of endocrine disruption. Ecological Applications. 10(4): 949-957.

Abstract: This invited paper stresses that the existence of 

synthetic chemicals in the environment can no longer be left 

out of management considerations as was done in the 1950-

1970s. Further, it points out that by neglecting to prevent their 

release into the environment their cryptic, transgenerational, 

developmental effects would never have been discovered. If 

it had not been for wildlife harbingers, endocrine disruption 

might have continued to be overlooked. WATER QUALITY

113. Colorado River Basin Salinity Control Forum. 1975. 

Proposed water quality standards for salinity including 

numeric criteria and plan of implementation for salinity 

control, Colorado River system. Colorado River Basin 

Salinity Control Forum (The Program). 134 p.

Abstract: This report, prepared by the 7-State Colorado River 

Basin Salinity Control Forum, presents, in a single document, 

the water quality standards for salinity submitted for adoption 

by each of the states within the Basin. WATER QUALITY

114. Conine, K.H.; Anderson, B.W.; Ohmart, R.D.; Drake, 

J.F. 1978. Responses of riparian species to agricultural 

habitat conversion. In: Johnson, R.R.; McCormick, J.F., 

tech. coords. Strategies for protection and management 

of floodplain wetlands and other riparian ecosystems. 

Gen. Tech. Rep. WO-12. Washington, DC: U.S. Department of Agriculture, Forest Service: 248-262.

Abstract: Approximately 1,100 ha of agricultural land and 

540 ha of riparian habitats were censused over a 14-month 

period in the lower Colorado River Valley to examine relative 

use of these areas by riparian birds. Many species did not use 

agricultural lands at all; insectivorous species suffered severe 

losses through agricultural conversions, while others used 

agricultural area to a high degree. Also, agricultural-riparian 

edge was beneficial to certain species. AGRICULTURE

115. Cooper, D.J.; Emerick, J.C. 1987. The effects of acid mine 

drainage on a Carex aquatilis fen in the Colorado Rocky 

Mountains. In: Mutz K.M.; Lee, L.C., tech. coords. 

Wetland and riparian ecosystems of the American 

West: Proceedings of the eighth annual meeting of the 

Society of Wetland Scientists; 1987 May 26-29; Seattle, 

WA. Denver, CO: Planning Information Corp.: 96-100.

Abstract: A Carex aquatilis dominated fen in the Peru Creek 

drainage, Colorado Rocky Mountains, has been impacted by 

drainage from the Pennsylvania Mine. Metal concentrations 

in leaves, roots, and standing dead leaves were analyzed 

and it was determined that Zn, Cu, and Al were probably 

the leading cause of poor plant health. WATER QUALITY

116. Cooper, D.J.; Merritt, D.M.; Anderson, D.C.; Chimner, 

R.A. 1999. Factors controlling the establishment of 

Fremont cottonwood seedlings on the Upper Green 

River, USA. Regulated Rivers: Research and Management. 15: 419-440.

Abstract: Declines in cottonwood (Populus spp.) recruitment 

along alluvial reaches of large rivers in arid regions of the 

western United States have been attributed to modified flow 

regimes, lack of suitable substrate, insufficient seed rain, and 

increased inter-specific competition. We evaluated whether 

and how these factors were operating during 1993–1996 to 

influence demographics of Fremont cottonwood along reaches 

of the Green and Yampa Rivers near their confluence in 

northwestern Colorado. The data presented herein suggest 

that dense tamarisk thickets preclude or hinder cottonwood 

establishment by depleting soil moisture and creating shade. 

Tamarisk removal prior to a controlled flood could facilitate 

cottonwood seedling establishment in existing tamarisk 

stands. MULTIPLE THREATS

117. Courtois, L.A. 1984. Temporal desert riparian systems—the 

Mojave River as an example. In: Warner, R.E.; Hendrix, 

K.M., eds. California riparian systems: Ecology, 

conservation, and productive management. Berkeley: 

University of California Press: 688-693.

Abstract: During years of high precipitation, temporal riparian zones form on the dry lake playas within the Mojave 

River drainage and can exist for several years. This is followed 

by establishment of pioneer aquatic species, which eventually give way to halophytes as surface waters recede. Once 

surface water evaporates the alkali sink vegetation becomes 

reestablished. The greatest threat to this ecological balance is 

the increased human demand for water and the establishment 

of permanent agriculture. AGRICULTURE
28 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

118. Crawford, C.S; Ellis, L.M.; Molles, M.C., Jr.; Valett, 

H.M. 1996. The potential for implementing partial 

restoration of the Middle Rio Grande ecosystem. In: 

Shaw, D.W.; Finch, D.M., tech. coords. Desired future 

conditions for southwestern riparian ecosystems: 

Bringing interests and concerns together. Gen. Tech. 

Rep. RM-272. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 93-99.

Abstract: The Rio Grande currently inundates only a small 

portion of its riparian forests during late spring runoff. Such 

flood events were once responsible for the germination of 

cottonwoods and willows along the river, for a mosaic of 

wetland mixed with different aged stands of forest, and for 

enhancement of decomposition and nutrient cycling. River 

regulations in this century have decoupled the linkage between 

the floodplain and the river and led to senescence without 

replacement of the once dominant native cottonwoods in the 

Middle Rio Grande reach. FLOODS, FLOW REGULATION

119. Croonquist, M.J.; Brooks, R.P. 1991. Use of avian and 

mammalian guilds as indicators of cumulative impacts 

in riparian-wetland areas. Environmental Management. 

15(5): 701-714.

Abstract: This paper presents a method of assessing cumulative effects of human activities on bird and mammal 

communities by using response guilds to reflect how species 

theoretically respond to habitat disturbance at the landscape 

level. The authors hypothesized that the response-guild approach would predict post-disturbance wildlife community 

changes more efficiently than a single-species approach. 

They found that avian response guilds reflected habitat disturbance more accurately than mammalian response guilds. 

MULTIPLE THREATS

120. Crouch, G.L. 1961. Inventory and analysis of wildlife 

populations and habitat, South Platte River Valley. Final 

report. Federal Aid in Wildlife Restoration Project W104-R-1-2. Colorado Game and Fish Department. 68 p.

Abstract: This investigation sought to determine the relative 

difference in wildlife populations and habitat conditions on 

grazed and ungrazed bottomlands along the South Platte River 

in Logan County, Colorado. Results of wildlife counts showed 

that significantly larger numbers of ducks, deer, pheasants, 

quail, cottontail rabbits, squirrels, hawks, crows, and small 

birds were seen on the ungrazed land; more shorebirds were 

counted on the grazed tract, while there were no significant 

differences in the numbers of doves, eagles, horned owls, or 

magpies. GRAZING

121. Crouch, G.L. 1978. Effects of protection from livestock 

grazing on a bottomland wildlife habitat in northeastern 

Colorado. In: Graul, W.D.; Bissel, S.J., tech. coords. 

Lowland river and stream habitat in Colorado: A 

symposium ; 1978 Oct. 4-5; Greeley, CO. Lyons, CO: 

The Wildlife Society, Colorado Chapter; Boulder, CO: 

Colorado Audubon Council: 118-125.

Abstract: Vegetation on a bottomland wildlife habitat protected from grazing for 7 and 25 years was compared to an 

adjacent grazed tract along the South Platte River in northeastern Colorado. Overall cover and height of the understory was 

about twice as great on the ungrazed area for each evaluation, 

but did not change appreciably over the 18-year interval. A 

significant decrease in the number of cottonwood trees on 

both areas, particularly the grazed area, requires attention 

by wildlife habitat managers. GRAZING

122. Crouse, M.R. 1987. New approaches to riparian area 

management on public lands. In: Mutz K.M.; Lee, 

L.C., tech. coords. Wetland and riparian ecosystems of 

the American West: Proceedings of the eighth annual 

meeting of the Society of Wetland Scientists; 1987 May 

26-29; Seattle, WA. Denver, CO: Planning Information 

Corp.: 32-35.

Abstract: Riparian areas are among the most productive 

ecosystems found on lands managed by the U.S. Bureau of 

Land Management (BLM). Conflicts often occur over what 

land uses are appropriate for these areas. This paper traces 

the BLM’s current multidiscipline approach for managing 

riparian areas, including timber harvest practices and grazing options. Case histories of successful stream restoration 

are presented. MULTIPLE THREATS

123. Crumpacker, D.W. 1984. Regional riparian research and 

a multi-university approach to the special problem of 

livestock grazing in the Rocky Mountains and Great 

Plains. In: Warner, R.E.; Hendrix, K.M., eds. California 

riparian systems: Ecology, conservation, and productive management. Berkeley: University of California 

Press: 413-423.

Abstract: This paper presents a selected survey of Rocky 

Mountain/Great Plains riparian research with emphasis on 

livestock grazing impacts and management. An analogy 

is made to California, considering the State as a region.

GRAZING

124. Dahl, T.E. 2005. Status and trends of wetlands in the 

conterminous United States, 1998 to 2004. Washington, 

DC: U.S. Department of the Interior, Fish and Wildlife 

Service: 112 p.

Abstract: This report provides scientific and statistical 

results on the progress that has been made toward achieving 

national wetland quality goals. The Status and Trends Study 

collects data on wetland acreage gains and losses; it does 

not assess the quality or condition of the nation’s wetlands. 

MULTIPLE THREATS
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 29

125. Dahl, T.E.; Johnson, C.E. 1991. Status and trends of 

wetlands in the conterminous United States, mid-1970’s 

to mid-1980’s. Washington, DC: U.S. Department of the 

Interior, Fish and Wildlife Service. 28 p.

Abstract: This report covers the mid-1970s to the mid-1980s, a 

period in which Federal, State, and local government programs 

and policies began to affect wetland use and conversion. Even 

though the data contained in this report generally predates 

more recent wetlands legislation, they provide information 

that can help to assess the effectiveness of public policies 

and programs that have been intended to reduce the loss of 

the Nation’s remaining wetlands. MULTIPLE THREATS

126. Dahlem, E.A. 1978. The Mahogany Creek watershed – 

with and without grazing. In: Cope, O.B., ed. Proceedings of the forum—grazing and riparian/stream 

ecosystems; 1978 November 3-4; Denver CO. Arlington, 

VA: Trout Unlimited: 31-34.

Abstract: Heavy livestock use in the Mahogany Creek 

watershed had led to deterioration of trout habitat and to a 

general decline in vegetative condition, both riparian and 

non-riparian. In 1976 fencing excluded livestock grazing 

first from the creek and than from the entire watershed. Only 

after complete removal of livestock was significant riparian 

habitat improvement accomplished along the creek. GRAZING

127. Davis, F.W.; Keller, E.A.; Parikh, A.; Florsheim, J. 1988. 

Recovery of the chaparral riparian zone after wildfire. 

In: Abell, D.L., coord. Proceedings of the California 

riparian systems conference: Protection, management, and 

restoration for the 1990’s; 1988 September 22-24; Davis, 

CA. Gen. Tech. Rep. PSW-110. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest 

Forest and Range Experiment Station: 194-203.

Abstract: After the Wheeler Fire in southern California in 

1985, sediment deposition and vegetation recovery was monitored in a section of the severely burned chaparral riparian 

zone of the North Fork of Matilija Creek. Increased runoff 

was accompanied by low magnitude debris flow and fluvial 

transport gravel, most of which was added to the channel 

and nearby hillslopes by post-fire dry ravel. The pre-burn 

riparian forest was dominated by white alder, California 

sycamore, and coastal live oak. Regeneration of these species was entirely by resprouting, due to the absence of local 

viable seed sources. Recovery of the herb layer was affected 

strongly by the seeding of Italian ryegrass. Species richness 

of annuals decreased considerably in the second year, when 

perennials dominated the riparian zone. FIRE

128. Davis, G.A. 1977. Management alternatives for the 

riparian habitat in the Southwest. In: Johnson, R.R.; 

Jones, D.A., tech. coords. Importance, preservation and 

management of riparian habitat: A symposium; 1977 

July 9; Tucson, AZ. Res. Pap. RM-43. Fort Collins, CO: 

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

Mountain Forest and Range Experiment Station: 59-67.

Abstract: Exploitation by man has significantly altered 

the riparian habitat in the Southwest. For decades, the 

primary or dominant use of riparian habitat has been 

water management; other values were not considered. 

Management alternatives and objectives are evaluated 

for environmental consequences. FLOW REGULATION, 

GROUNDWATER DEPLETION

129. Davis, T. 1995. The Southwest’s last real river: Will it 

flow on? High Country News. 27(11): 1, 10-11.

Abstract: This paper describes the threats the San Pedro 

River faces at the beginning of the new millennium. MULTIPLE THREATS

130. Deardorff, D.; Wadsworth, K. 1996. Cooperative management of riparian forest habitat to maintain biological quality and ecosystem integrity. In: Shaw, D.W.; 

Finch, D.M., tech. coords. Desired future conditions for 

southwestern riparian ecosystems: Bringing interests 

and concerns together. Gen. Tech. Rep. RM-272. Fort 

Collins, CO: U.S. Department of Agriculture, Forest 

Service, Rocky Mountain Forest and Range Experiment 

Station: 227-229.

Abstract: The New Mexico State Land Office has initiated 

a rare plant survey of State trust land, an inventory and assessment of riparian areas on the trust land, and the development of a biological resources data base and information 

management system. Some riparian sites that still belong to 

the trust have been negatively impacted by livestock such 

that biological quality and ecological integrity of these sites 

have been reduced. This paper reviews potential solutions of 

how the State Land Office can manage trust land and restore 

riparian sites. GRAZING

131. DeBano, L.F.; Ffolliott, P.F. 1996. Flow of water and 

sediments through Southwestern riparian systems. In: 

Shaw, D.W.; Finch, D.M., tech. coords. Desired future 

conditions for southwestern riparian ecosystems: 

Bringing interests and concerns together. Gen. Tech. 

Rep. RM-272. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 128-134.

Abstract: This paper describes streamflow, sediment movement and vegetation interactions within riparian systems of the 

southwestern United States. Intermittent streamflow coupled 

with the discontinuous storage and subsequent movement of 

sediment though channel systems in response to fire and other 

disturbances is extremely complex, and can be difficult to 

interpret when assessing responses of southwestern riparian 

system to management. MULTIPLE THREATS

132. DeBano, L.F.; Hansen, W.R. 1989. Rehabilitating 

depleted riparian areas using channel structures. In: 

Gresswell, R.E.; Barton, B.A.; Kershner, J.L., eds. 

Practical approaches to riparian resource management: 
30 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

An educational workshop; 1989 May 8-11; Billings 

MT. U.S. Department of the Interior, Bureau of Land 

Management: 143-148.

Abstract: Abusive land use activities have deteriorated valuable riparian areas in the southwestern United States. Loss of 

protective cover causes erosion, which reduces soil moisture 

and channel stability that is necessary for maintaining riparian 

areas. Review of three rehabilitation projects in New Mexico 

and Colorado indicate that channel structures store sediment, 

stabilize channels, raise water table, and enhance riparian 

vegetation. MULTIPLE THREATS

133. DeBano, L.F.; Schmidt, L.J. 1989a. Improving southwestern riparian areas through watershed management. Gen. 

Tech. Rep. RM-182. Fort Collins, CO: U.S. Department 

of Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 33 p.

Abstract: The overall objectives of this document are to 

provide (1) a state-of-the-art report on riparian hydrology 

in the Southwest, and (2) general guidelines for improving 

hydrologic relationships in naturally occurring and man 

induced riparian areas throughout the arid Southwest. As a 

result, the document focuses on improving riparian areas in 

harsh arid environments where intermittent and ephemeral 

streamflow predominate. This document is not intended to 

be a review of the direct effect of grazing on riparian areas 

for fishery habitat. GRAZING, FLOW REGULATION

134. DeBano, L.F.; Schmidt, L.J. 1989b. Interrelationship 

between watershed conditions and health of riparian 

areas in southwestern United States. In: Gresswell, R.E.; 

Barton, B.A.; Kershner, J.L., eds. Practical approaches 

to riparian resource management: An educational workshop; 1989 May 8-11; Billings MT. U.S. Department 

of the Interior, Bureau of Land Management: 45-52.

Abstract: Sensitive hydrologic interrelationships exist 

between watershed condition and the health of associated 

riparian areas in the southwestern United States. The impact 

of extensive unmanaged livestock grazing, wildfires, and 

past forest clearing, coupled with numerous small linear 

perturbations such as travelways, low standard roads, and 

livestock trails, has dramatically illustrated the interrelationship between watershed conditions and riparian health. 

MULTIPLE THREATS

135. DeBano, L.F.; Rinne, J.N.; Medina, A.L. 1996. Understanding and managing southwestern riparian-stream 

ecosystems: national forest systems and forest services 

research partnership. In: Neary, D.G.; Ross, K.C.; Coleman, S.S., eds. In: Proceedings of the national hydrology 

workshop; 1992 April 27- May 1; Phoenix, AZ. Gen. 

Tech. Rep. RM-279. Fort Collins, CO: U.S. Department 

of Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 96-102.

Abstract: Partnerships between research scientists and land 

managers can facilitate the application of research findings. 

Successful partnerships developed between Rocky Mountain 

Station scientists and Southwestern Region staffs have been 

involved in addressing riparian-stream interactions. These 

successful partnerships involve several interpersonal and 

organizational considerations. Examples and keys to successful partnerships are described. MULTIPLE THREATS

136. Dennis, N.B.; Ellis, D.; Arnold, J.R.; Renshaw, D.L. 1984. 

Riparian surrogates in the Sacramento/San Joaquin 

Delta and their habitat values. In: Warner, R.E.; Hendrix, K.M., eds. California riparian systems: Ecology, 

conservation, and productive management. Berkeley: 

University of California Press: 566-576.

Abstract: The distribution and condition of riparian vegetation in the Sacramento/San Joaquin Delta has been highly 

modified during 130 years of land reclamation, construction, 

and maintenance of the present levee system and the conversion of the land to agricultural cultivation. A variety of 

vegetation complexes with partial riparian attributes exists 

under a few natural, but primarily induced conditions in the 

Delta, providing some of the wildlife values associated with 

historic Delta riparian vegetation. AGRICULTURE

137. Dewine J.M.; Cooper, D.J. 2008. Canopy shade and the 

successional replacement of tamarisk by native box 

elder. Journal of Applied Ecology. 45: 505-514.

Abstract: In this study the authors investigated the establishment chronology, competition, and comparative shade tolerances of tamarisk and box elder to determine the superior 

competitor and to predict successional trajectories in mixed 

stands. The study found box elder to be a superior competitor 

to tamarisk and attributes the success of tamarisk in North 

America to its high stress tolerance, superior dispersal ability 

and absence of natural enemies. INVASIVE SPECIES

138. Dieter, C.D.; McCabe, T.R. 1989. Habitat use by beaver 

along the Big Sioux River in eastern South Dakota. 

In: Gresswell, R.E.; Barton, B.A.; Kershner, J.L., eds. 

Practical approaches to riparian resource management: 

An educational workshop; 1989 May 8-11; Billings, 

MT. U.S. Department of the Interior, Bureau of Land 

Management: 135-140.

Abstract: Habitat use by beavers was investigated in grazed 

and ungrazed areas along the Big Sioux River in eastern 

Sioux River in eastern South Dakota. A greater proportion of 

trees were cut by beavers in ungrazed than in grazed areas. 

Over half of the trees damaged by beaver either resprouted 

or remained alive and standing. GRAZING

139. Ditton, R.B.; Schmidly, D.J.; Boeer, W.J.; Graefe, A.R. 

1977. A survey and analysis of recreational and livestock 

impact on the riparian zone of the Rio Grande in Big 

Bend National Park. In: Proceedings of river recreation 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 31

management and research symposium; 1977 January 

24-27; Minneapolis, MN. Gen. Tech. Rep. NC-28. St. 

Paul, MN: U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station: 256-266.

Abstract: The Rio Grande of the Big Bend National Park 

has experienced dramatic increases in recreational and water 

resource use. This paper assesses the actual and potential 

impact on the river and on associated land area ecosystems 

from present levels of human usage. MULTIPLE THREATS

140. Dixon, M.D.; Stromberg, J.C.; Price, J.T.; Galbraith, H.; 

Fremier, A.K.; Larsen, E.W. 2009. Chapter 8: Potential effects of climate change on the Upper San Pedro 

riparian ecosystem. In: Stromberg, J.C.; Tellman, B.J., 

eds. Ecology and conservation of the San Pedro River. 

Tucson, AZ: University of Arizona Press: 57-72.

Abstract: The upper San Pedro is used as a case study to 

explore the effects of climate change. This study uses a 

range of climate change scenarios to explore the sensitivity 

of the riparian ecosystem, in particular the composition and 

dynamics of riparian vegetation. The authors state that their 

results are considered preliminary and suggest that several 

successional changes in the riparian vegetation of the upper 

San Pedro floodplain are likely. CLIMATE CHANGE

141. Dotzenko, A.D.; Papamichos, N.T.; Romine, D.S. 1967. 

Effects of recreational use on soil and moisture conditions in Rocky Mountain National Park. Journal of Soil 

and Water Conservation. 22: 196-197.

Abstract: This study found that soil compacting effect of 

intensive recreational use produces infiltration, runoff and 

erosion problems. Heavy use significantly reduced the surface 

soil moisture content. RECREATION

142. Dougherty, S.T.; Berry; C.A.; Deimel, M.A. 1987. 

Hydrology and vegetation in montane and subalpine 

wetlands of Colorado. In: Mutz K.M.; Lee, L.C., 

tech. coords. Wetland and riparian ecosystems of the 

American West: Proceedings of the eighth annual meeting 

of the Society of Wetland Scientists. 1987 May 26-29; 

Seattle WA. Denver, CO: Planning Information Corp.: 81-84.

Abstract: Limited published information is available on the 

relationships between hydrology and vegetation in montane 

and subalpine wetland of the central and southern Rocky 

Mountains. This paper addresses hydrology and vegetation of 

these wetlands and cites two recent research projects related 

to this topic. It also suggests the considerations in predicting 

impacts for wetland systems. MULTIPLE THREATS

143. Duncan, K.W.; Schemnitz, S.D.; Suzuki, M.; Homesley, 

Z.; Cardenas, M. 1993. Evaluation of saltcedar control—

Pecos River, New Mexico. In: Tellman, B.; Cortner, 

H.J.; Wallace, M.G.; DeBano, L.F.; Hamre, R.H., tech. 

coords. Riparian management: Common threads and 

shared interests; A western regional conference on river 

management strategies; 1993 Feb 4-6; Albuquerque, 

NM. Gen. Tech. Rep. RM-226. Fort Collins, CO: U.S. 

Department of Agriculture Forest Service, Rocky Mountain Forest and Range Experiment Station: 207-210.

Abstract: This paper introduces the Pecos River Native 

Riparian Restoration Project, which aims to (1) demonstrate 

native wetlands and wildlife habitat improvement through 

saltcedar management, (2) demonstrate effective, economical 

and environmentally sound salt cedar control, and (3) monitor possible hydrologic effects from saltcedar control and 

management. INVASIVE SPECIES

144. Dwire, K.A.; Kauffman, J.B. 2003. Fire and riparian 

ecosystems in landscapes of the western USA. Forest 

Ecology and Management. 178: 61–74.

Abstract: The objectives of this paper are to: (1) synthesize 

the limited research conducted on fire regimes in riparian 

areas relative to uplands, (2) summarize the distinctive features of riparian zones that influence the properties of fire, 

(3) discuss the impacts of land use as they may affect fire 

behavior in riparian areas, and (4) describe the adaptations 

of riparian plant species to fire. FIRE

145. Ehrhart, R.C.; Hansen, P.L. 1997. Effective cattle 

management in riparian zones: A field survey and 

literature review. Riparian Technical Bulletin No. 3. 

Billings,MT: U.S. Department of the Interior: Bureau 

of Land Management: 92 p.

Abstract: This report contains (1) a brief review of the characteristics and functions of riparian ecosystem in the western 

United States and the impact livestock grazing has had on 

them, (2) a presentation and analysis of the data collected over 

four field seasons, (3) a “Principles and Techniques” section 

that suggests general principles for developing successful 

grazing management strategies for the riparian areas and 

offers examples of good management techniques based both 

on field observations and the current literature, (4) a selected 

bibliography identifying especially useful material readily 

available to land managers and private operators. GRAZING

146. Ellis, L.M.; Crawford, C.S.; Molles, M.C., Jr. 1998. 

Comparison of litter dynamics in native and exotic 

riparian vegetation along the Middle Rio Grande of 

central New Mexico, U.S.A. Journal of Arid Environments. 38: 283–296.

Abstract: This paper presents a long-term study of how 

southwestern riparian ecosystems have been altered by both 

changed river flow regimes and introduced exotic plants, by 

investigating structural and functional aspects of the Rio 

Grande riparian forest in central New Mexico. The study 

compares (1) litter production, (2) litter decomposition, and 

(3) quantities of stored organic litter at cottonwood- and 

saltcedar-dominated sites during 1991 through 1996. It also 

compares the responses of these two vegetation types to 

experimental flooding. INVASIVE SPECIES
32 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

147. Elmore, W. 1986. Riparian management issues, overview 

and background. In: Smits, J.H., ed. Management of 

riparian areas. Washington, DC: Public Lands Council: 1-4.

Abstract: This paper briefly discusses riparian processes 

and the management challenges of the livestock industry to 

do more with lands management than they have done in the 

past. GRAZING

148. Elmore, W. 1988. Rangeland and riparian systems. 

In: Abell, D.L., coord. Proceedings of the California 

riparian systems conference: Protection, management, 

and restoration for the 1990’s; 1988 September 22-24; 

Davis, CA. Gen. Tech. Rep. PSW-110. Berkeley, CA: 

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

Southwest Forest and Range Experiment Station: 93-95.

Abstract: The management and recovery of degraded riparian systems is a major conservation issue. Presently there are 

many grazing management strategies being applied based on 

the name of the technique with little incorporation of basic 

stream processes. Managers must understand the exact workings of grazing strategies and the individual processes of 

each stream before prescribing solutions to degraded riparian 

systems. GRAZING

149. Elmore, W. 1992. Riparian responses to grazing practices. In: Naiman, R.J., ed. Watershed management: 

Balancing sustainability and environmental change. 

New York: Springer-Verlag: 442-457.

Abstract: By the early 1900s many of the stream systems 

throughout the western rangelands were severely damaged 

or eliminated because of improper livestock use. Riparian 

exclosures throughout the West have proven that livestock 

grazing is not necessary to improve stream riparian systems. 

However, recent experience has shown that with proper 

grazing, livestock can be present while stream systems are 

improving. GRAZING

150. Elmore, W.; Beschta, R.L. 1987. Riparian areas: Perception in management. Rangelands. 9(6): 260-265.

Abstract: The objectives of this paper are (1) to promote 

awareness and discussion of riparian issues by and among 

livestock owners, land managers, environmentalists, biologists 

and the general public; (2) to identify the characteristics and 

benefits of productive riparian systems; and (3) to encourage 

managers of public and private lands to reconsider the effects 

to control channels structurally. GRAZING

151. Elmore W.; Kauffman, B. 1994. Riparian and watershed 

systems: Degradation and restoration. In: Vavra, M.; 

Laycock, W.A.; Pieper, R.D., eds. Ecological implications of livestock herbivory in the West. Denver CO: 

Society for Range Management: 212-231.

Abstract: This chapter examines causes of degradation of 

riparian ecosystems and upland watersheds. It looks at historical reasons for their current state and at present restoration 

efforts and strategies. GRAZING

152. Emerick, J.C. 1988. The restoration potential for wetlands impacted by acid mine drainage in the Colorado 

Rocky Mountains. In: Mutz, K.M.; Cooper, D.J; Scott, 

M.L.; Miller, L.K., tech. coords. Restoration, creation 

and management of wetland and riparian ecosystems in 

the American West: Proceedings of a symposium; 1988 

November 14-16; Denver, CO. Boulder, CO: Society of 

Wetland Scientists, Rocky Mountain Chapter, 109-111.

Abstract: Water pollution by acid mine drainage is a significant environmental problem in Colorado and other western 

States. There are close to 10,000 inactive mines in Colorado, 

many that discharge acid mine drainage, or produce leachate 

with characteristics similar to mine dumps or mill tailings. 

This paper discusses the impacts effects and solutions to this 

problem. MINING

153. Engel-Wilson, R.W.; Ohmart, R.D. 1978. Floral and 

attendant faunal changes on the lower Rio Grande between Fort Quitman and Presidio, Texas. In: Johnson, 

R.R.; McCormick, J.F., tech. coords. Strategies for 

protection and management of floodplain wetlands 

and other riparian ecosystems. Gen. Tech. Rep. WO12. Washington, DC: U.S. Department of Agriculture, 

Forest Service: 139-147.

Abstract: Written and photographic documentation from 

explorers and settlers demonstrate that the floodplain was 

historically dominated by cottonwood-willow and screwbean 

mesquite communities. Past and present land and water use 

practices have resulted in an almost complete elimination of 

native tree species and dominance by the exotic saltcedar. 

Avian census data from the area show higher bird population 

densities and diversities in the select mature cottonwoodwillow communities than in mature saltcedar communities. 

INVASIVE SPECIES

154. England, A.S.; Foreman, L.D.; Laudenslayer, W.F., Jr. 

1984. Composition and abundance of bird populations 

in riparian systems of the California deserts. In: Warner, 

R.E.; Hendrix, K.M., eds. California riparian systems: 

Ecology, conservation, and productive management. 

Berkeley: University of California Press: 694-705.

Abstract: Avian population diversity, density, and species 

richness in desert riparian systems were analyzed. Riparian 

systems associated with permanent water are very limited. 

From a management standpoint the greatest threats to these 

systems are posed by recreationists, grazing, livestock and 

feral burros, as well as mining operations. MULTIPLE 

THREATS
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 33

155. Ewel, K.C. 1978. Riparian ecosystem: Conservation of 

their unique characters. In: Johnson, R.R.; McCormick, 

J.F., tech. coords. Strategies for protection and management of floodplain wetlands and other riparian 

ecosystems. Gen. Tech. Rep. WO-12. Washington, DC: 

U.S. Department of Agriculture, Forest Service: 56-62.

Abstract: Riparian ecosystems have two essential characteristics: laterally flowing water that rises and falls at least once 

within a growing season , and a high degree of connectedness 

with other ecosystems. Other pulses such as fire and hurricanes 

may also be important in ecosystem maintenance. Changes in 

hydroperiod or amplitude of water level fluctuation produce 

the most dramatic changes in riparian communities. Changes 

in neighboring ecosystems that have high rates of exchange 

of energy and nutrients with riparian ecosystems, may also 

have significant effects. MULTIPLE THREATS

156. Fenchel, G.; Oaks, W.; Swenson, E. 1989. Selecting desirable woody vegetation for environmental mitigation and 

controlling wind erosion and undesirable plants in the 

Rio Grande and Pecos River Valleys of New Mexico. 

Five-year interim report (1983-1987). Los Lunas, NM: 

U.S. Department of Agriculture, Soil Conservation 

Service, Plant Materials Center.

Abstract: Soil erosion along the Rio Grande and Pecos 

Rivers and flood plains has detrimental effects on the riparian habitat and the environment. Actions of man and the 

spread of undesirable species such as saltcedar have been 

associated with the decline of the riparian and flood plain 

habitats. River channel maintenance activities, as mandated 

by law, can require measures such as revegetation. This 

report describes the work conducted by the USDI Bureau 

of Reclamation and the USDA Soil Conservation Service to 

control erosion at the Elephant Butte and Caballo Reservoirs. 

MULTIPLE THREATS

157. Fenner, P.; Brady, W.W.; Patton, D.R. 1985. Effects of 

regulated water flows on regeneration of Fremont cottonwood. Journal of Range Management. 38: 135-138.

Abstract: This study investigated the effects of releasing 

water from dams on the establishment of riparian vegetation. The hypothesis examined was that dams modify local 

conditions to the extent that some plant species find the 

riparian zone less favorable or even unfavorable as habitat. 

DAM CONSTRUCTION

158. Fierke, M.K.; Kauffman, J.B. 2005. Structural dynamics of riparian forests along a black cottonwood successional gradient. Forest Ecology and Management. 

215: 149–162.

Abstract: The objectives of this study were to quantify and 

describe successional change, stand development, and biomass 

accumulation in black cottonwood riparian forests of the Willamette River, Oregon from recently established seedlings on 

fresh alluvial substrate to late-successional stands. FLOODS

159. Finch, D.M. 1996. Research and management of soil, 

plant, animal, and human resources in the Middle 

Rio Grande Basin. In: Shaw, D.W.; Finch, D.M., tech. 

coords. Desired future conditions for southwestern 

riparian ecosystems: Bringing interests and concerns 

together. Gen. Tech. Rep. RM-272. Fort Collins, CO: 

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

Mountain Forest and Range Experiment Station: 69-76.

Abstract: The Rocky Mountain Forest and Range Experiment Station initiated a research program in 1994 called, 

“Ecology, diversity, and sustainability of soil, plant, animal, 

and human resource of the Rio Grande Basin.” Its mission 

focuses on the development and application of new knowledge 

to sustain ecological systems and human populations in the 

Middle Rio Grande Basin. Research studies emphasize upland 

ecology and management, linkages between watersheds and 

riparian zones, sensitive fish and wildlife populations and 

species of concern, and past and present cultural resources. 

MULTIPLE THREATS

160. Finch, D.M. 1999. Recovering southwestern willow 

flycatcher populations will benefit riparian health. In: 

McCabe, Richard E.; Loos, Samantha E., eds. Transactions of the 64th North American Wildlife and Natural 

Resources Conference; 1999 March 26-30; Burlingame, 

CA. Washington, DC: Wildlife Management Institute: 

275-291.

Abstract: This paper briefly reviews the distribution, taxonomy and population status of the southwestern willow 

flycatcher then follows with a survey of problems and threats 

faced by fragmented flycatcher populations in the Southwest. 

It concludes with a summary of potential actions that various 

stakeholders, including private citizens, can take to benefit the 

flycatcher as well as important strides to take in conserving 

and recovering riparian ecosystems. MULTIPLE THREATS

161. Fleischner, T.L. 1994. Ecological costs of livestock grazing in Western North America. Conservation Biology. 

8(3): 629-644.

Abstract: Livestock grazing is the most widespread land 

management practice in western North America with seventy 

percent of the western United States both public and private 

land being grazed. This paper discusses the many ecological 

costs of grazing, such as loss of biodiversity, disruption of 

ecosystem functions, and change in the physical characteristics of both terrestrial and aquatic habitats. This research 

pertains particularly to riparian ecosystems, which is where 

livestock often congregate and can have the greatest impact. 

The author advocates for the involvement of conservation 

biologists in the ongoing social and scientific dialogue on 

grazing issues to promote healthy ecosystems. GRAZING

162. Fleming, C.M.; Kunkle, S.H.; Flora, M.D. 1996. Riparian 

wetlands and visitor use management in Big Bend National Park, Texas. In: Shaw, D.W.; Finch, D.M., tech. 
34 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

coords. Desired future conditions for southwestern 

riparian ecosystems: Bringing interests and concerns 

together. Gen. Tech. Rep. RM-272. Fort Collins, CO: 

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

Mountain Forest and Range Experiment Station: 212-215.

Abstract: Resource impacts, resulting from careless use 

and overuse, has been documented by several surveys at a 

number of the more popular areas in the Big Bend National 

Park’s riparian or wetland habitats. This paper discusses these 

impacts and the park management actions that are underway 

or under consideration to deal with them. The management 

actions are aimed at limiting resource damage to wetland and 

riparian habitat while permitting visitor use of the resources. 

RECREATION

163. Flenniken, M.; Mceldowney, R.R.; Leiniger, W.C.; Frasier 

G.W. 2001. Hydrologic responses of a montane riparian ecosystem following cattle use. Journal of Range 

Management. 54: 567-574.

Abstract: Riparian areas link streams with their terrestrial 

catchments and decrease water pollution by trapping sediments from upland sources before they reach streams or lakes. 

Livestock grazing in riparian areas is a controversial practice. 

If not properly managed, cattle can cause degradation to both 

the riparian zone and adjacent water body. Vegetative, soil microtopographical, microchannel, and hydrograph parameters 

were measured in a montane riparian community in northern 

Colorado to quantify the effects of cattle on overland flow and 

runoff characteristics. Results from this study have improved 

our understanding of flow and runoff processes following 

cattle use of a riparian ecosystem. GRAZING

164. Follstad Shah, J.J.; Dahm, C.N. 2008. Flood regime and 

leaf fall determine soil inorganic nitrogen dynamics 

in semiarid riparian forests. Ecological Applications. 

18(3): 771-788.

Abstract: This study examines the effects of flood regime 

on plant community and soil inorganic nitrogen dynamics 

in riparian forests dominated by native Populus detoides

var. wislizenii Eckenwalder (Rio Grande cottonwood) and 

nonnative Tamarix chinensis Lour. (saltcedar) along the 

regulated middle Rio Grande of New Mexico. The authors 

recommend utilizing naturalized flows that help maintain 

riparian groundwater elevations between 1 and 3 m in reaches 

with mature P. deltoides or where P. deltoides revegetation 

is desired. Other recommendations include identifying areas 

that naturally undergo long periods of inundation and consider restoring these areas to seasonal wetlands and using 

native xeric-adapted riparian plants to revegetate long and 

short inter-flood interval sites where groundwater elevations 

commonly drop below 3 m. FLOODS, INVASIVE SPECIES

165. Fonseca, J. 1993. A county government perspective. In: 

Tellman, B.; Cortner, H.J.; Wallace, M.G.; DeBano, 

L.F.; Hamre, R.H., tech. coords. Riparian management: 

Common threads and shared interests. A western regional conference on river management strategies; 1993 

Feb 4-6; Albuquerque, NM. Gen. Tech. Rep. RM-226. 

Fort Collins, CO: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Forest and Range 

Experiment Station: 22-24.

Abstract: The Pima County hydrologist describes how the 

county is dealing with the threat of losing riparian vegetation 

due to development and land use change on private lands. 

URBANIZATION

166. Fornwalt, P.J.; Kaufmann, M.R.; Huckaby, L.S.; Stohlgren, T.J. 2009. Effects of past logging and grazing on 

understory plant communities in a montane Colorado 

forest. Plant Ecology. 203: 99-109.

Abstract: The authors investigate the long-term impacts of 

settlement-era activities on understory plant communities by 

comparing understory composition at a historically logged 

and grazed site to that of an environmentally similar site that 

was protected from past use. The study found that species 

richness and cover within functional groups rarely differed 

between sites in either upland or riparian areas, though 

compositional differences were apparent in riparian zones. 

MULTIPLE THREATS

167. Fort, D.D. 1993. The protection of riparian areas: New 

approaches for new times. In: Tellman, B.; Cortner, 

H.J.; Wallace, M.G.; DeBano, L.F.; Hamre, R.H. tech., 

coords. Riparian management: Common threads and 

shared interests. A western regional conference on river 

management strategies; 1993 Feb 4-6; Albuquerque, 

NM. Gen. Tech. Rep. RM-226. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky 

Mountain Forest and Range Experiment Station: 70-75.

Abstract: In this brief paper, an appraisal of the opportunities 

and barriers to riparian protection and restoration is presented. 

The focus is on public policy and current opportunities for 

riparian protection. MULTIPLE THREATS

168. Fox, K. 1977. Importance of riparian ecosystems: Economic considerations. In: Johnson, R.R.; Jones, D.A., 

tech. coords. Importance, preservation and management 

of riparian habitat: A symposium; 1977 July 9; Tucson, 

AZ. Res. Pap. RM-43. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain 

Forest and Range Experiment Station: 19-22.

Abstract: Efforts to preserve riparian habitat must recognize 

man’s growing demands to put this area to other use. Economic 

pressures, at conflict with environmental concerns, pose an 

inevitable threat to vegetation and wildlife. A compromise 

in the balance or preservation and development must be 

maintained. MULTIPLE THREATS

169. French, R.H.; Woessner, W.W. 1981. Erosion and salinity 

problems in arid regions. In: Proceedings of the specialty 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 35

conference; 1981 Aug. 10-14; San Francisco, CA. ASCE 

Water Forum 81. New York: American Society of Civil 

Engineers: 1319-1326.

Abstract: The mineral quality problem in southwestern rivers is a complex problem, which is critically important on a 

regional, national and international basis. Mineral quality, 

commonly termed salinity or total dissolved solids, is a 

particularly serious water quality problem on the main stem 

of the Colorado River. Man-made sources of salinity include 

municipal and industrial consumptive use of water, irrigation, 

and evaporation from reservoirs. WATER QUALITY

170. Furman, D. 1988. San Joaquin River riparian habitat 

below Bellow Friant Dam: Preservation and restoration. 

In: Abell, D.L., coord. Proceedings of the California 

riparian systems conference: Protection, management, 

and restoration for the 1990’s; 1988 September 22-24; 

Davis, CA. Gen. Tech. Rep. PSW-110. Berkeley, CA: 

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

Southwest Forest and Range Experiment Station: 79-82.

Abstract: Riparian habitat along California’s San Joaquin 

River in the 25 miles between Friant Dam and Freeway 99 

occurs on approximately 6 percent of its historic range. It 

is threatened directly and indirectly by increased urban encroachment such as residential housing, certain recreational 

uses, sand and gravel extraction, agriculture, and road construction. MULTIPLE THREATS

171. Gage, E.A.; Cooper, D.J. 2004. Constraints on willow 

seedling survival in a Rocky Mountain montane floodplain. Wetlands. 24(4): 908-911.

Abstract: In this study, authors analyzed the influence of soil 

texture and relative elevation on patterns of willow seedling 

survival along a relatively degraded, small-order montane 

stream. Results indicate that both soil water availability and 

scour by spring floods influence the spatial and temporal 

patterns of willow seedling survival on point bars along 

small-order montane streams. A better understanding of the 

factors governing willow seedling survival can help managers identify potential constraints on the natural recovery or 

restoration of degraded riparian communities and to predict 

vegetation responses to anthropogenic and natural disturbances, such as large floods and climate change. FLOODS, 

CLIMATE CHANGE

172. Gazal, R.M.; Scott, R.L.; Goodrich, D.C.; Williams, 

D.G. 2006. Controls on transpiration in a semiarid 

riparian cottonwood forest. Agricultural and Forest 

Meteorology. 137: 56-67.

Abstract: This paper presents the seasonal patterns of cottonwood transpiration at two contrasting riparian sites in 

order to better understand how the trees transpire in relation 

to canopy structure, evaporative demand, and groundwater 

depth along the San Pedro River in southeastern Arizona. 

Riparian cottonwood forests are exposed to extreme 

fluctuations in water availability and transpiration demand 

throughout the growing season, and their access to shallow 

groundwater sources determines their structural and physiological responses to drought. Spatial and temporal variation 

in depth to groundwater induces drought stress in cottonwood, threatening their productivity and existence along the 

river systems throughout much of western United States. 

GROUNDWATER DEPLETION, DROUGHT

173. Gergel, S.E.; Turner, M.G.; Miller, J.R.; Melack, J.M.; 

Stanley, E.H. 2002. Landscape indicators of human 

impacts to riverine systems. Aquatic Sciences. 64(2): 

118-128.

Abstract: This paper briefly reviews the chemical, biotic, 

hydrologic and physical habitat assessment approaches commonly used in riverine systems. It then discusses how landscape indicators can be used to assess the status of rivers by 

quantifying land cover changes in the surrounding catchment, 

and contrasting landscape-level indicators with the more 

traditionally used approaches. MULTIPLE THREATS

174. Gillen, R.L.; Krueger, W.C.; Miller, R.F. 1985. Cattle 

use of riparian meadows in the Blue Mountains of 

Northeastern Oregon. Journal of Range Management. 

38: 205-209.

Abstract: The objectives of this study were to (1) determine the 

intensity and pattern of cattle use of small riparian meadows 

under continuous and deferred rotation grazing management 

and (2) compare the temperature and relative humidity regimes of riparian and upland plant communities. GRAZING

175. Glinski, R.L. 1977. Regeneration and distribution of sycamore and cottonwood trees along Sonoita Creek, Santa 

Cruz County, Arizona. In: Johnson, R.R.; Jones, D.A., 

tech. coords. Importance, preservation and management 

of riparian habitat: A symposium; 1977 July 9; Tucson, 

AZ. Res. Pap. RM-43. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain 

Forest and Range Experiment Station: 116-123.

Abstract: This study describes the effects of livestock grazing 

and streambed erosion on the regeneration and distribution of 

sycamore and cottonwood trees. Sycamore reproduce from 

root and trunk sprouts and, because of this, their distribution 

is not as likely to change significantly. Cottonwood reproduction was nearly absent in areas grazed by cattle, and was 

confined to the narrow erosion channel. If this regeneration 

pattern continues, the future maximum width of the cottonwood forest will decrease nearly 60%. GRAZING

176. Gradek, P.; Saslaw, L.; Nelson, S. 1988. An application 

of BLM’s riparian inventory procedure to rangeland 

riparian resources in the Kern and Kaweah River 

watersheds. In: Abell, D.L., coord. Proceedings of the 
36 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

California riparian systems conference: Protection, 

management, and restoration for the 1990’s; 1988 September 22-24; Davis, CA; Gen. Tech. Rep. PSW-110. 

Berkeley, CA: U.S. Department of Agriculture, Forest 

Service, Pacific Southwest Forest and Range Experiment Station: 109-115.

Abstract: The Bakersfield District of the Bureau of Land 

Management conducted an inventory of rangeland riparian 

systems using a new method developed by a Bureau-wide 

task force to inventory, monitor, and classify riparian areas. 

Data on vegetation composition were collected for 65 miles 

of streams and entered into a hierarchical vegetation classification system. Ratings of hydrologic function, vegetative structure, and vegetative use by grazing animals were 

employed to measure impacts by land uses and potential for 

recovery with proper management. GRAZING

177. Graf, W.L. 2006. Downstream hydrologic and geomorphic 

effects of large dams on American rivers. Geomorphology. 79(3-4): 331-360.

Abstract: This paper explains the specific methods and results for investigating the downstream effects of large dams 

on hydrology, and geomorphology. It also addresses regional 

variation of hydrology and geomorphology as affected by 

dams, and explores the ecologic implications of downstream 

influence of dams. DAM CONSTRUCTION

178. Gray, M.V.; Greaves, J.M. 1984. Riparian forest as habitat 

for the Least Bell’s Vireo. In: Warner, R.E.; Hendrix, 

K.M., eds. California riparian systems: Ecology, 

conservation, and productive management. Berkeley: 

University of California Press: 605-611.

Abstract: Data are presented on vegetation structure in Least 

Bell’s Vireo breeding habitats. A discussion of vegetation 

and several other factors relevant to breeding success of 

this endangered species is presented. Recommendations are 

made for actions, such as limiting grazing and recreation, to 

ensure the future of the subspecies as a breeding inhabitant 

of riparian forests. MULTIPLE THREATS

179. Green, D.M.; Kauffman, J.B. 1989. Nutrient cycling at 

the land-water interface: The importance of the riparian zone. In: Gresswell, R.E.; Barton, B.A.; Kershner, 

J.L., eds. Practical approaches to riparian resource 

management: An educational workshop; 1989 May 8-11; 

Billings, MT. U.S. Department of the Interior, Bureau 

of Land Management: 61-68.

Abstract: Recent research has shown that low reductionoxidation potential result in denitrification and that phosphorus immobilization processes occur within intact riparian 

ecosystems, thereby greatly influencing water quality. The 

effects of grazing and other anthropogenic disturbances can 

alter these biogeochemical cycles resulting in drastic alterations in riparian vegetation composition and productivity, 

aquatic ecosystems and water quality. WATER QUALITY

180. Green, D.M.; Kauffman, J.B. 1995. Succession and 

livestock grazing in a Northeastern Oregon riparian 

ecosystem. Journal of Range Management. 48: 307-313.

Abstract: Comparisons of vegetation dynamics of riparian 

plant communities under livestock use and exclusions over 

a 10-year period were quantified in a Northeastern Oregon 

riparian zone. Results indicate that influences of herbivory 

on species diversity and evenness varies from one community 

to another, and basing management recommendation on one 

component ignores the inherent complexity of riparian ecosystems. The objective of this study was to quantify changes 

in vegetation species composition over 10 years of eight 

grazed and ungrazed riparian plant communities. GRAZING

181. Gregory, S.V.; Swanson, F.J.; McKee, W.A.; Cummins, 

K.W. 1991. An ecosystem perspective of riparian zones: 

Focus on links between land and water. Bioscience. 

41: 540-551.

Abstract: Bank erosion is integral to the functioning of 

river ecosystems. It is a geomorphic process that promotes 

riparian vegetation succession and creates dynamic habitats 

crucial for aquatic and riparian plants and animals. River 

managers and policymakers, however, generally regard bank 

erosion as a process to be halted or minimized in order to 

create landscape and economic stability. Bank erosion is now 

recognized as a desirable attribute of rivers. Recent advances 

in the understanding of bank erosion processes and of associated ecological functions, as well as of the effects and 

failure of channel bank infrastructure for erosion control, 

suggest that alternatives to current management approaches 

are greatly needed. A conceptual framework for alternatives 

is developed in this paper that addresses bank erosion issues. 

The alternatives conserve riparian linkages at appropriate 

temporal and spatial scales, consider integral relationships 

between physical bank processes and ecological functions, 

and avoid secondary and cumulative effects that lead to the 

progressive channelization of rivers. By linking geomorphologic processes with ecological functions, the significance 

of channel bank erosion in sustainable river and watershed 

management is addressed. MULTIPLE THREATS

182. Groeneveld, D.P.; Griepentrog, T.E. 1985. Interdependence of groundwater, riparian vegetation, and streambank stability: A case study. In: Johnson, R.R.; Ziebell, 

C.D.; Patton, D.R.; Ffolliott, P.F.; Hamre, R.H., tech. 

coords. Riparian ecosystems and their management: 

reconciling conflicting uses. First North American riparian conference; 1985 April 16-18; Tucson, AZ. Gen. 

Tech. Rep. RM-120. Fort Collins, CO: U.S. Department 

of Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 44-48.

Abstract: Groundwater is closely coupled with streamflow 

to maintain water supply to riparian vegetation, particularly 

where precipitation is seasonal. A case study is presented where 

Mediterranean climate and groundwater extraction are linked 

with the decline of riparian vegetation and subsequent severe 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 37

bank erosion on the Carmel River in Carmel Valley, California. GROUNDWATER DEPLETION, FLOW REGULATION

183. Hadley, R.F.; Emmett, W.W. 1998. Channel changes 

downstream from a dam. Journal of the American Water 

Resources Association. 34: 629-637.

Abstract: A flood-control dam was completed during 1979 

on Bear Creek, a small tributary stream to the South Platte 

River in the Denver, Colorado, area. Before and after dam 

closure, repetitive surveys between 1977 and 1992 at five 

cross sections downstream of the dam documented changes 

in channel morphology. During this 15-year period, channel 

width increased slightly, but channel depth increased by more 

than 40 percent. Within the study reach, stream gradient decreased and median bed material sizes coarsened from sand 

in the pools and fine gravel on the rime to median coarse 

gravel throughout the reach. The most striking visual change 

was from a sparse growth of streamside grasses to a dense 

growth of riparian woody vegetation. DAM CONSTRUCTION

184. Hain, F. 2006. New threats to forest health require 

quick and comprehensive research response. Journal 

of Forestry. 104(4): 182-186.

Abstract: Exotic pest introductions are a global threat occurring at an unprecedented rate. Comprehensive research 

programs are required at the onset to prevent the spread of 

the invasive insects, pathogens, or plants, and rehabilitate 

and restore native habitats and ecosystems. Unfortunately, 

much of the current research on invasives is piecemeal. Past 

experiences with exotic and native pests provide some valuable 

lessons about how we should approach research programs on 

invasive organisms. The infrastructure required for effectively 

administering comprehensive research programs is complex. 

An example is discussed. INVASIVE SPECIES, INSECTS 

AND DISEASE

185. Hair, D.; Stowell, R. 1986. South Fork Clearwater River 

habitat enhancement: Annual report FY 1985. In: Natural 

propagation and habitat improvement Volume II. Project 

No. 84-5. Portland, OR: U.S. Department of Energy, 

Bonneville Power Administration, Division of Fish and 

Wildlife. 282 p.

Abstract: This annual report deals with additional treatments 

to improve fish habitat in the South Fork Clearwater River 

that had not been covered in previous reports. Fish habitat 

problems are the result of overgrazing and previous dredge 

mining for gold, which eliminated the riparian meadow. 

MULTIPLE THREATS

186. Hall, F.C. 1988. Characterization of riparian systems. In: 

Raedeke, K.J., ed. Streamside Management: Riparian 

wildlife and forestry interactions. Institute of Forest 

Resources Contribution 59. Seattle, WA: University of 

Washington: 7-11.

Abstract: The purpose of this introductory paper is simply 

to bring together in a general way some of the more important factors influencing riparian ecosystems. These include 

natural factors, such as seasonal flows, floods, beavers, and 

fire. Management activities such as livestock grazing, timber 

harvest, and the building of roads, dams, and other structures 

generate unnatural impacts. MULTIPLE THREATS

187. Hancock, J.L. 1989. Selling a successful riparian management program: A public land manager’s viewpoint. 

In: Gresswell, R.E.; Barton, B.A.; Kershner, J.L., eds. 

Practical approaches to riparian resource management: 

An educational workshop; 1989 May 8-11; Billings, 

MT. U.S. Department of the Interior, Bureau of Land 

Management: 1-3.

Abstract: The purpose of this paper is to discuss the human 

relationship keys to selling a successful riparian area management program. Giving riparian areas in central Oregon 

as examples, the author shows how to deal with management 

threats to riparian areas, such as livestock grazing. GRAZING

188. Haney, J. 2007. Rivers and water management in the 

Southwest. Southwest Hydrology; 6(3): 22-23, 34-35.

Abstract: The web of water law, policy, and management 

in the West has developed over decades, varies by State, 

and is exceedingly complex. That complexity reflects an attempt to achieve equity among the various water use sectors: 

municipal, agricultural, mining, and commercial/industrial. 

This paper discusses how water management can be used to 

prevent further loss and impairment of southwest rivers and 

wetlands. MULTIPLE THREATS

189. Hansen, P. 1993. Developing a successful riparianwetland grazing management plan for the Upper Ruby 

River cattle and horse allotment in southwestern Montana. In: Tellman, B.; Cortner, H.J.; Wallace, M.G.; 

DeBano, L.F.; Hamre, R.H., tech. coords. Riparian 

management: Common threads and shared interests; 

A western regional conference on river management 

strategies; 1993 Feb 4-6; Albuquerque, NM. Gen. Tech. 

Rep. RM-226. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 328-335.

Abstract: The major concern with the Upper Ruby cattle and 

horse grazing allotment has been the health of the riparian 

zone. The historic use of the riparian zone along the Upper 

Ruby River and its major tributaries has left much of it in a 

degraded state. This paper provides background information, 

identifies problems, describes how to develop management 

objectives, and proposes a monitoring plan. GRAZING

190. Hedlund, J.D. 1984. USDA planning process for Colorado River Basin salinity control. In: French, R.H., ed. 

Salinity in watercourses and reservoirs: Proceedings of 
38 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

the 1983 international symposium on state-of-the-art 

control of salinity; 1984 July 13-15, Salt Lake City UT. 

Boston MA: Butterworth Publishers: 63-77.

Abstract: Man-caused increases in salinity result from diversion, consumptive use, and salt-loading in return flows. 

The largest man-induced increase in salinity is caused by the 

concentrating effect of irrigated agriculture and salt loading 

associated with it. This paper discusses the problem and 

solutions in more detail. WATER QUALITY

191. Hehnke, M.; Stone, C.P. 1978. Value of riparian vegetation to avian populations along the Sacramento River 

system. In: Johnson, R.R.; McCormick, J.F. tech., coords. 

Strategies for protection and management of floodplain 

wetlands and other riparian ecosystems. Gen. Tech. 

Rep. WO-12. Washington, DC: U.S. Department of 

Agriculture, Forest Service: 228-235.

Abstract: The purpose of this study was to determine the 

value of riparian habitat to birds along the Sacramento River. 

Spring and fall migratory peaks of bird density and diversity 

were higher in riparian and associated vegetation than in 

riprapped and associated vegetation. Riparian vegetation 

appears to control avian density and diversity in associated 

vegetation. MULTIPLE THREATS

192. Heifner, M.A. 1978. Sand and gravel mining in Colorado 

riparian habitats. In: Graul, W.D.; Bissel, S.J., tech. 

coords. Lowland river and stream habitat in Colorado: 

A symposium; 1978 October 4-5; Greeley, CO. Greeley, 

CO: Wildlife Society and Colorado Audubon Council: 

141-147.

Abstract: This paper discusses the extent and general areas 

of sand and gravel mining in riparian habitats along Colorado 

streams and rivers. It emphasizes the impacts of mining on 

the loss of long-established terrestrial wildlife habitats and the 

prospects of loss mitigation by replacement with a combined 

terrestrial/aquatic habitat. MINING

193. Hendrickson, D.A.; Minckley, W.L. 1984. Cienegas—

Vanishing climax communities of the American Southwest. Desert Plants. 6(3): 131-175.

Abstract: This paper discusses various factors that have led 

to the destruction of cienegas in the American Southwest. 

The authors state that cienegas conditions can be restored 

at historic sites by provision of constant water supply and 

amelioration of catastrophic flooding events. FLOODS, 

FLOW REGULATION

194. Henszey, R.J.; Wolff, S.W.; Wesche, T.A.; Skinner, Q.D.; 

Hubert, W.A. 1988. Assessment of a flow enhancement 

project as a riparian and fishery habitat mitigation effort. 

In: Mutz, K.M.; Cooper, D.J; Scott, M.L.; Miller, L.K., 

tech. coords. Restoration, creation and management 

of wetland and riparian ecosystems in the American 

West: Proceedings of a symposium; 1988 November 

14-16; Denver, CO. Boulder, CO: Society of Wetland 

Scientists, Rocky Mountain Chapter: 88-93.

Abstract: As part of mitigation procedures for impacts caused 

by the Cheyenne Stage II water development project in the 

Little Snake River Drainage, Wyoming, the flow in a previously ephemeral watercourse on the east slope of the Laramie 

Range is being enhanced to create a perennial stream. Water 

used to enhance this flow is obtained by trans-basin diversion. The mitigation is being done in hopes of enhancing the 

riparian and fishery habitat. This paper describes the overall 

mitigation project, the study design, and preliminary results. 

WATER DIVERSION

195. Henszey, R.J.; Pfeiffer, K.; Keogh, J.R. 2004. Linking 

surface- and groundwater levels to riparian grassland 

species along the Platte River in Central Nebraska, 

USA. Wetlands. 24(3): 665-687.

Abstract: This study suggests that for Platte River riparian 

grasslands, high water levels are more influential than mean, 

median, or low water levels. Land-management practices (i.e., 

grazing, haying, and extended rest) affected six species by a 

change in frequency or a shift in position along the water-level 

gradient. Four general plant communities composed of species 

responding individually to the water-level gradient and other 

factors were identified for Platte River riparian grasslands: 

emergent, sedge meadow, mesic prairie, and dry ridge. Plant 

response curves are the first step toward predicting how 

plants responding to riparian-grassland water levels might 

also respond to river management. MULTIPLE THREATS

196. Hesseldenz, T.F. 1984. Developing a long-term protection plan for the McCloud River, California. In: Warner, 

R.E.; Hendrix, K.M., eds. California riparian systems: 

Ecology, conservation, and productive management. 

Berkeley: University of California Press: 784-794.

Abstract: The McCloud River drainage in northern California 

hosts numerous species with rare or threatened status that 

have, until recently, been indirectly protected by a history 

of private ownership and inaccessibility of large parts of the 

drainage. Dam construction, water diversion, road construction, timber harvest, angling pressure, and limestone quarrying 

now threaten the drainage and have encouraged intensive planning efforts to lessen their impacts. MULTIPLE THREATS

197. Hink, V.C.; Ohmart, R.D. 1984. Middle Rio Grande 

biological survey. Tempe: Arizona State University, 

Center for Environmental Studies. 160 p.

Abstract: The objectives of this study were to identify the 

major types of riparian habitat within the study reach, and 

to characterize the vegetation and terrestrial vertebrate communities of each type. The study focused on the area within 

and including the drains and levees that parallel the river. 

MULTIPLE THREATS
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 39

198. Hirsch, A.; Segelquist, C.A. 1978. Protection and management of riparian ecosystems: Activities and views of the 

US Fish and Wildlife Service. In: Johnson, R.R.; McCormick, J.F., tech. coords. Strategies for protection and 

management of floodplain wetlands and other riparian 

ecosystems. Gen. Tech. Rep. WO-12. Washington, DC: 

U.S. Department of Agriculture, Forest Service: 344-352.

Abstract: Land use changes and water resource development 

activities are jeopardizing valuable riparian ecosystem. Current activities of the Fish and Wildlife Service providing for 

the protection of riparian resources are described, and several 

initiatives are outlined to strengthen riparian ecosystem protection and management programs. MULTIPLE THREATS

199. Holway, D.A. 2005. Edge effects of an invasive species 

across a natural ecological boundary. Biological Conservation. 121: 561–567.

Abstract: This paper examines the spatial pattern and ecological effects of a biological invasion at well-delineated and 

abrupt edges between riparian corridors and coastal sage scrub 

at 10 sites in southwestern California. In general, edge effects 

occurring at natural boundaries should receive increased attention as they might disrupt ecosystems not greatly altered 

by human activity. INVASIVE SPECIES

200. Hook, D.D.; Murray, M.M.; DeBell, D.S.; Wilson, B.C. 

1987. A technique for assessing the influence of shallow 

water table levels on red alder (Alnus rubra Bong.) family 

performance. In: Mutz, K.M.; Lee, L.C., tech. coords. 

Wetland and riparian ecosystems of the American 

West: Proceedings of the eighth annual meeting of the 

Society of Wetland Scientists; 1987 May 26-29; Seattle 

WA. Denver, CO: Planning Information Corp.: 248-252.

Abstract: Depth of rusting on iron rods placed in the soil 

near red alder trees was used to assess the relationship between tree height at age 5 years and the soil water table level 

during the dormant season. The iron rods proved to be a 

sensitive indicator of water table levels. By using regression 

and covariance analysis, differences in family response were 

found over the range of 0 – 30 cm deep water tables. It was 

concluded that the technique is sensitive, simple to use, and 

inexpensive. GROUNDWATER DEPLETION

201. Hoover, D.E.; Gipson, P.S.; Pontius, J.S.; Hynek, A.E. 

2001. Short-term effects of cattle exclusion on riparian 

vegetation in Southeastern Kansas. Transactions of the 

Kansas Academy of Science. 104(3–4): 212–222.

Abstract: This paper describes the effects of cattle exclusion on the structure and composition of riparian vegetation observed in a 2-year study in southeastern Kansas. A 

significant difference in the percentage of bare ground and 

herbaceous vegetation height was observed between the 

grazed and ungrazed study sites. Excluding cattle from closed 

canopy riparian woodlands in southeastern Kansas resulted 

in a positive short-term response of understory herbaceous 

vegetation. Results suggest that riparian fencing may be an 

effective management tool for restoring understory vegetation in riparian communities grazed by cattle in the eastern 

Great Plains. GRAZING

202. Horton, J.L.; Kolb, T.E.; Hart, S.C. 2001. Responses 

of riparian trees to interannual variation in ground 

water depth in a semi-arid river basin. Plant, Cell and 

Environment. 24: 293-304.

Abstract: The study presented in this paper investigated the 

physiological and growth responses of native (Populus and 

Salix) and exotic (Tamarix) riparian trees to groundwater 

availability at the free-flowing Hassayampa River, Arizona, 

during dry (1997) and wet (1998) years. GROUNDWATER 

DEPLETION, INVASIVE SPECIES

203. Horton, J.L.; Kolb, T.E.; Hart, S.C. 2001a. Physiological 

response to groundwater depth varies among species 

with river flow regulation. Ecological Applications. 

11(4): 1046–1059.

Abstract: This paper presents findings of an investigation of the physiological condition of two native species, 

Populus fremontii and Salix gooddingii, and one invasive 

exotic, Tamarix chinensis, along gradients of groundwater 

availability at a dam-regulated river and a free-flowing river 

in the Sonoran Desert in Arizona. DAM CONSTRUCTION, 

INVASIVE SPECIES

204. Horton, J.S. 1977. The development and perpetuation of 

the permanent tamarisk type in the phreatophyte zone 

of the Southwest. In: Johnson, R.R.; Jones, D.A., tech. 

coords. Importance, preservation and management of 

riparian habitat: A symposium; 1977 July 9; Tucson, AZ. 

Res. Pap. RM-43. Fort Collins, CO: U.S. Department 

of Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 124-127.

Abstract: Several species of tamarisk were introduced into 

the United States in the 19th century for ornamental use. Saltcedar became naturalized and by the 1920s was a dominant 

shrub along the southwestern rivers. Its aggressive character 

suits it to be a permanent dominant in much of the phreatophyte vegetation of this region. Successful management of 

this vegetation for any resource must carefully consider its 

ecological characteristics. INVASIVE SPECIES

205. Houghton, C.J.; Michny, F.J. 1988. Middle Sacramento 

River refuge: A feasibility study. In: Abell, D.L., coord. 

Proceedings of the California riparian systems conference: Protection, management, and restoration for the 

1990’s; 1988 September 22-24; Davis, CA. Gen. Tech. 

Rep. PSW-110. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and 

Range Experiment Station: 83-87.
40 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

Abstract: The woodlands and other streamside habitat 

of Sacramento River’s riparian system have been severely 

reduced within the last century. This riparian habitat and 

its ability to sustain diverse populations of fish, migratory 

birds, mammals, and other wildlife have been significantly 

impacted by water control projects, agriculture developments, 

and other land uses. MULTIPLE THREATS

206. Howard, S.W.; Dirar, A.E.; Evans, J.O.; Provenza, F.D. 

1983. The use of herbicides and/or fire to control saltcedar (Tamarix). Proceedings of the Western Society 

of Weed Science. 36: 65-72.

Abstract: Experiments conducted over 2 years have indicated 

that managed burning and spraying to control saltcedar is only 

effective in July. Burning in late July prevented 64 percent of 

the plants from resprouting the year following the treatment, 

whereas spraying the resprouts with herbicide 1 month after 

prevented 99 percent or better, of the plants from resprouting. 

INVASIVE SPECIES

207. Howe, W.H.; Knopf, F.L. 1991. On the imminent decline 

of Rio Grande cottonwoods in central New Mexico. The 

Southwestern Naturalist. 36(2): 218-224.

Abstract: The combination of paucity of cottonwood regeneration over the last 30 years, the rapid colonization 

during this century of Russian-olive and saltcedar into the 

valley, and the current river channel management practices 

suggest that the Rio Grande riparian woodland will become 

dominated by the exotic shrubs over the next 50 to 100 years. 

INVASIVE SPECIES

208. Hubbard, J.P. 1977. Importance of riparian ecosystems: 

Biotic considerations. In: Johnson, R.R.; Jones, D.A., 

tech. coords. Importance, preservation and management 

of riparian habitat: A symposium; 1977 July 9; Tucson, 

AZ. Res. Pap. RM-43. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain 

Forest and Range Experiment Station: 14-18.

Abstract: The emphasis on the importance of riparian 

ecosystems to the biota of the Southwest has concentrated 

mainly on the question of surface water, as in the case of 

fishes and of certain other animals and plants. However, 

there are other riparian features involved that should also be 

mentioned, and among the most important is the vegetation 

characteristic of these ecosystems described in this paper. 

MULTIPLE THREATS

209. Hubbs, C.; Miller, R.R.; Edwards, R.J.; Thompson, 

K.W.; Marsh, E.; Garrett, G.P.; Powell, G.L.; Morris, 

D.J.; Zerr, R.W. 1977. Fishes inhabiting the Rio Grande, 

Texas and Mexico, between El Paso and the Pecos confluence. In: Johnson, R.R.; Jones, D.A., tech. coords. 

Importance, preservation and management of riparian 

habitat: A symposium; 1977 July 9; Tucson, AZ. Res. 

Pap. RM-43. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 91-97.

Abstract: The fishes of the middle part of the Rio Grande 

can be divided into three fauna assemblages: the saline Rio 

Grande fauna upstream from the Conchos confluence; the 

Rio Conchos-Rio Grande fauna in the Rio Grande between 

Conchos and Pecos; and the tributary creek fauna that depend 

on tributary creeks for all or part of their life history stages. 

Endangered species are found in the last assemblage, but two 

presumed endangered species seem to have been eliminated 

already. MULTIPLE THREATS

210. Hunter, W.C.; Anderson, B.W.; Ohmart, R.D. 1985. 

Summer avian community of Tamarix habitats in three 

southwestern desert riparian systems. In: Johnson, R.R.; 

Ziebell, C.D.; Patton, D.R.; Ffolliott, P.F.; Hamre, R.H., 

tech. coords. Riparian ecosystems and their management: reconciling conflicting uses. First North American 

riparian conference; 1985 April 16-18; Tucson, AZ. Gen. 

Tech. Rep. RM-120. Fort Collins, CO: U.S. Department 

of Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 128-134.

Abstract: Data from three southwestern river systems were 

used to assess avian response to saltcedar. Species were 

grouped by breeding biology and groups responded differently in their occurrence in saltcedar among the valleys. 

Biogeographical and climatic factors may explain these differences. INVASIVE SPECIES

211. Huxman, T.E.; Scott, R.L. 2007. Climate change, vegetation dynamics, and the landscape water balance. 

Southwest Hydrology. 6(1): 28-37.

Abstract: Elevated CO2 concentrations favor woody plants 

over grasses and may accelerate woody-plant thickening or 

encroachment. Changes in the ratio of woody plants to grasses 

can influence the landscape water balance by affecting recharge and streamflow. Larger woody vegetation populations 

would be expected to increase the amount of water leaving 

landscapes as evapotranspiration. CLIMATE CHANGE

212. Jackson, J.; Ball, J.T.; Rose, M.R. 1990. Assessment of 

the salinity tolerance of eight Sonoran Desert riparian 

trees and shrubs. Final Report. Reno, NV: Desert Research Institute, University of Nevada System, Biological 

Sciences Center: 102 p.

Abstract: Eight species of Sonoran Desert riparian trees and 

shrubs were examined in a greenhouse-based study of salinity 

tolerance at six levels. The publication addresses the results 

of these studies. A serious problem related to plant growth in 

arid regions is the accumulation of salt in soil. Whereas salts 

in humid soils are leached by continuous precipitation, arid 

soils zones accumulate high salt content through processes 

of evaporation and upward capillary movement of moisture 

from the water table. WATER QUALITY
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 41

213. Janda R.J. 1977. Summary of watershed conditions in the 

vicinity of Redwood National Park, California. OpenFile Report 78-25. Menlo Park, CA: U.S. Department 

of the Interior: Geological Survey: 82 p.

Abstract: The Redwood Creek Unit of Redwood National 

Park is located in the downstream end of an exceptionally 

rapidly eroding drainage basin. Spatial distribution and types 

of erosional landforms, observed in the field and on timesequential aerial photos, measured sediment load. The lithologic heterogeneity of streambed materials indicate (1) that 

sediment discharges reflect a complex suite of natural and 

man-induced mass movement and fluvial erosion processes 

operating on a geologically heterogeneous, naturally unstable 

terrain, and (2) that although infrequent exceptionally intense 

storms control the timing and general magnitude of major erosion events, the loci, types, and amounts of erosion occurring 

during those events are substantially influenced by land use. 

Erosional impact of past timber harvest in the Redwood Creek 

basin reflect primarily the cumulative impact of many small 

erosion problems caused not so much by removal of standing timber as by the intensity and pattern of ground surface 

disruption accompanying removal. FOREST HARVESTING

214. Jensen, S.; Platts, W.S. 1987. Processes influencing riparian ecosystems. In: Mutz, K.M.; Lee, L.C., tech. coords. 

Wetland and riparian ecosystems of the American 

West: Proceedings of the eighth annual meeting of the 

Society of Wetland Scientists. 1987 May 26-29; Seattle 

WA. Denver, CO: Planning Information Corp.: 228-232.

Abstract: A primary function of rivers, the transport of water 

and sediments, is influenced by the interaction of geologic, 

climatic, hydrologic, geomorphic, pedogenic, and biotic processes. These same processes are principally responsible for 

the development of riparian ecosystems, which regulate the 

flux of water and sediments. The distribution, values, qualities and dynamics of riverine/riparian ecosystems may be 

viewed as responses to these co-evolutionary processes. As 

man assumes a dominant role in orchestrating the dynamics 

of watersheds, an understanding of these relationships is essential for proper management of riverine/riparian ecosystems. 

MULTIPLE THREATS

215. Jensen, 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: 307-404.

Abstract: This paper addresses restoration of degraded 

riverine/riparian habitat in the Great Basin Hydrographic 

Region and the Snake River Subregion of the Columbia River 

Hydrographic Region. It discusses degraded habitat and 

how to identify when values and beneficial uses have been 

impaired. Further, it describes how to achieve the goal of 

restoration by returning a habitat to a less impaired state. In 

its appendix it gives nine examples of riparian restoration 

projects, including cause of their degradation as well as 

past and current threats to these riverine/riparian habitats. 

MULTIPLE THREATS

216. Johnson, A.S. 1989. The thin green line: Riparian corridors and endangered species in Arizona and New 

Mexico. In: Mackintosh, G., ed. Preserving communities 

& corridors. Washington, DC: Defenders of Wildlife: 

35-46.

Abstract: The paper provides a historical account of the riparian communities in Arizona and New Mexico. It describes 

the negative impacts of grazing and land use change, namely 

agriculture, on these systems. 149 vertebrate species are listed 

for both States. This paper provides a detailed list for both 

States listing the threatened and endangered species occurring 

in each major riparian community. MULTIPLE THREATS

217. Johnson, B.; Merritt, D. 2009. The effects of wildfire on 

native tree species in the Middle Rio Grande bosques 

of New Mexico. Fort Collins, CO: Colorado State 

University. 43 p.

Abstract: The cottonwood bosques along the Middle Fork of 

the Rio Grande (MRG) form a ribbon of surviving habitat in 

what was once a vast ecosystem. Acknowledging the reality 

that widespread restoration of the historical hydrogeomorphic 

conditions that would support natural cottonwood reproduction is highly unlikely, management strategies for bosque 

forests have seen an increasing emphasis on preservation of 

the existing habitats and the established trees within. The 

objective of this study was to examine the effects of wildfires 

on cottonwood forests along the MRG to help inform the 

best management practices for these highly valued natural 

systems. FIRE

218. Johnson, B.A.; Riley, J.A. 1984. Price/San Rafael River 

Basin salinity investigation. In: French, R.H., ed. Salinity 

in watercourses and reservoirs: Proceedings of the 1983 

international symposium on state-of-the-art control of 

salinity; 1984 July 13-15; Salt Lake City, UT: Boston, 

MA: Butterworth Publishers: 407-416.

Abstract: The Price and San Rafael River Basins are located 

in east-central Utah and annually contribute 434,000 tons of 

salt to the Colorado River. Historical evidence indicates that 

agricultural practices are responsible for the greatest contribution. This paper discusses the problem and solutions in more 

detail. AGRICULTURE, WATER QUALITY

219. Johnson, R.R. 1978. The Lower Colorado River: A 

Western system. In: Johnson, R.R.; McCormick, J.F., 

tech. coords. Strategies for protection and management 

of floodplain wetlands and other riparian ecosystems. 

Gen. Tech. Rep. WO-12. Washington, DC: U.S. Department of Agriculture, Forest Service: 41-55.
42 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

Abstract: The historic look at the Colorado River illustrates 

the dramatic effects of human activity on most Western 

rivers. Engineering features for the management of water 

and electric power have resulted in increased evaporation, 

associated salinity, and other physiochemical changes; drastic reduction in many native plant and animal populations; 

increasing population of introduced species; and changes in 

erosional and sedimentation rates. MULTIPLE THREATS

220. Johnson, R.R.; Carothers, S.W. 1982. Riparian habitat 

and recreation: Interrelationships and impacts to the 

Southwest and Rocky Mountain region. Eisenhower 

Consortium Bulletin 12. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain 

Forest and Range Experiment Station: 31 p.

Abstract: Riparian habitats are characterized by outstanding species richness and population densities of both plants 

and animals. Increasing recreational pressures on these 

ecotones between water and surrounding uplands are forcing 

management agencies to re-analyze consumptive versus nonconsumptive resource allocations. MULTIPLE THREATS.

221. Johnson, R.R.; Haight, L.T. 1984. Riparian problems 

and initiatives in the American Southwest: A regional 

perspective. In: Warner, R.E.; Hendrix, K.M., eds. 

California riparian systems: Ecology, conservation, 

and productive management. Berkeley: University of 

California Press: 404-412.

Abstract: Destruction of much of the Southwest’s riparian 

zone is the result of waters by consumptive uses and by mechanical damages from grazing, mining, engineering activities 

and more recently with suburban and urban development. Only 

by an increase in active, scientific based management will 

we succeed in leaving even a viable remnant of Southwestern 

riparian ecosystems for posterity. MULTIPLE THREATS

222. Johnson R.R.; McCormick, J.F. 1978. tech. coords. 

Strategies for protection and management of floodplain 

wetlands and other riparian ecosystems. Proceedings 

of a symposium; 1978 December 11-13. Gen. Tech. 

Rep. WO-12. Washington, DC: U.S. Department of 

Agriculture, Forest Service: 410 p.

Abstract: This symposium brought together scientists 

from across the U.S.A. to discuss and develop strategies for 

managing and protecting wetlands and riparian ecosystems. 

Threats to that goal were addressed in numerous papers. 

MULTIPLE THREATS

223. Johnson, W.C.; Burgess, R.L.; Keammerer, W.C. 1976. 

Forest overstory vegetation and environment on the 

Missouri River floodplain in North Dakota. Ecological 

Monographs. 46: 59-84.

Abstract: The study area, bounded by two large reservoirs, 

includes the most extensive remnant of floodplain forest in 

the Dakotas. Structure and composition of the forest overstory 

are strongly related to stand age and horizontal and vertical position on the floodplain. Populus deltoids and Salix 

amygdaloides predominate in young stands on low terraces 

near the center of the floodplain. Fraxinus pennsylvanica, 

Acer negundo, Ulmus americana, and Quercus macrocarpa

predominate in old stands on high terraces near the edge of 

the floodplain. Stands intermediate in composition are uncommon because of the discontinuous meandering pattern 

of the river across its floodplain. Surface soil environment 

and species diversity change markedly during the course of 

succession. The soils of young stands are generally sandy 

and low in organic matter. Soil nutrient content and available 

water capacity are generally higher in older stands because 

of higher organic matter content and repeated inputs of nutrient rich silt from past floods. Tree species diversity initially 

increases as stands age, reaches a maximum in stands with 

mixtures of both pioneer and terminal species, and declines 

slightly in the oldest stands. Analyses of population structure 

indicate a recent decline in the establishment of small stems 

of Acer and Ulmus. Available data suggest that these changes 

can be attributed to the removal of periodic spring flooding 

caused by the presence and operation of the reservoirs. It is 

also hypothesized that the lack of seedling-sapling stands 

of Populus in the region is the result of a reduction in the 

meandering rate of the river following reservoir construction 

and poor seedbed conditions in the absence of flooding. DAM 

CONSTRUCTION

224. Johnson, R.R.; Haight, L.T.; Simpson, J.M. 1977. Endangered species vs. endangered habitats: A concept. In: 

Johnson, R.R.; Jones, D.A., tech. coords. Importance, 

preservation and management of riparian habitat: A 

symposium; 1977 July 9; Tucson, AZ. Res. Pap. RM43. Fort Collins, CO: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Forest and Range 

Experiment Station: 68-79.

Abstract: Although the great diversity within riparian ecosystems was recognized earlier, their extreme productivity 

was not discovered until this decade. The highest densities 

of nesting birds for North America have been reported from 

Southwest cottonwood riparian forests. Complete loss of 

riverine habitat in the Southwest lowlands could result in 

extirpation of 47 percent of the 166 species of birds which 

nest in this region. MULTIPLE THREATS

225. Johnson, T.D.; Kolb, T.E.; Medina, A.L. 2009. Do riparian plant community characteristics differ between 

Tamarix (L.) invaded and non-invaded sites on the 

upper Verde River, Arizona? Biological Invasions: doi 

10.1007/s10530-009-9658-2.

Abstract: This study sought to determine whether riparian 

vegetation characteristics differed between sites where Tamarix was present and sites where Tamarix was absent during 

invasion of the upper Verde. The results are contrary to other 

reports of Tamarix association with depauperate riparian 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 43

plant communities, and suggest that Tamarix invasion of a 

watershed with a relatively natural flow regime and a robust 

native plant community follows similar establishment patterns 

as the native riparian plant community. INVASIVE SPECIES

226. Johnson, W.C. 1992. Dams and riparian forests: Case 

study and the upper Missouri River. Rivers. 3: 229-242.

Abstract: This research examined the effects of altered 

flow and meandering rate of the Missouri River in central 

North Dakota on the compositional dynamics of floodplain 

forests. This was accomplished by estimating the rates 

of river erosion and deposition during pre-dam and postdam periods from historical maps and aerial photographs. 

Future changes in forest composition were simulated using 

a simple mathematical model based on measured rates of 

forest succession and river meandering for pre- and postdam periods. Simulations indicated a future decline in the 

areal extent of pioneer forests (cottonwood, willow) due to 

river regulation. Later successional species will dominate 

the future forests. Experimentation is needed to regenerate 

pioneer forests to maintain current levels of species diversity 

on the floodplain. DAM CONSTRUCTION

227. Johnson, W.C.; Dixon, M.D.; Simons, R.; Jenson, S.; 

Larosn, K. 1995. Mapping the response of riparian 

vegetation to possible flow reductions in the Snake 

River, Idaho. Geomorphology. 13: 159-173.

Abstract: This study was conducted to determine the relationship between the middle Snake River environment 

and its riparian vegetation, as a means of estimating the 

effects of possible future flow alterations on the quantity, 

quality, and distribution of riparian zone plants. Future 

flow reductions, either caused by greater water use or by 

climate change, could have a pervasive effect on riparian 

vegetation because streamflow is often the most important 

of all environmental factors affecting pattern and process 

in the riparian ecosystem. This paper presents the results of 

the subproject to map portions of the riverbed, which may 

be sensitive to vegetation expansion if flows are reduced in 

the future. One flow reduction scenario was developed and 

examined by combining field measurements of riparian vegetation gradients and river cross-sections, digital elevation 

modeling, and a geographic information system. CLIMATE 

CHANGE, FLOW REGULATION

228. Jonez, A.R. 1984. Controlling salinity in the Colorado 

River Basin, the arid West. In: French, R.H., ed. Salinity 

in watercourses and reservoirs: Proceedings of the 1983 

international symposium on state-of-the-art control of 

salinity; 1984 July 13-15, Salt Lake City UT. Boston 

MA: Butterworth Publishers: 337-347.

Abstract: The Colorado’s most insidious problem is increasing salinity. By the time the Colorado reaches Hoover Dam it 

is carrying 9 million tons of salt annually. About half of the 

present salt pollution comes from natural sources, while the 

other half is human caused. This paper discusses the problem 

and solutions in more detail. WATER QUALITY

229. Jonez, A.R.; Sharpe, F.P.; Strauss, P.; Deason, W.O. 

1978. Interaction of water management and riparian 

ecosystems: Attitudes, practices, and effects. In: Johnson, R.R.; McCormick, J.F., tech. coords. Strategies 

for protection and management of floodplain wetlands 

and other riparian ecosystems. Gen. Tech. Rep. WO12. Washington, DC: U.S. Department of Agriculture, 

Forest Service: 284-288.

Abstract: Under its broad mission of planning, developing, 

and managing water and related land resource projects, which 

supply water for agriculture, domestic, and industrial use in 

the 17 western states, the Bureau of Reclamation also fulfills 

the mission of preserving or mitigating riparian habitat. 

MULTIPLE THREATS

230. Judd, B.I.; Laughlin, J.M.; Guenther, H.R.; Handegrade, 

R. 1971. The lethal decline of mesquite on the Casa 

Grande National Monument. Great Basin Naturalist. 

31: 153-159.

Abstract: This study attempts to determine what factors 

may have been responsible for the massive lethal decline of 

the mesquite trees on the Casa Grande National Monument. 

The author concludes that the decline of the water table and 

mistletoe infestation may be the major contributors, with age 

of trees, insect infestation and natural successional process 

as secondary factors. MULTIPLE THREATS

231. Karr, J.R. 1999. Defining and measuring river health. 

Fresh Water Biology. 41(2): 221-234.

Abstract: Society benefits and depends on rivers, yet over 

the past century humans have dramatically changed rivers in 

the United States, even threatening river health. The concept 

of river health is a logical outgrowth of scientific principles, 

legal mandates, and changing societal values. This paper 

argues that the success in protecting the health of rivers 

depends on realistic models of human actions, landscapes, 

and river interactions, as well as biological monitoring, the 

use of multimetric biological indices, and the ability to communicate the observed results to citizens and political leaders. 

Several examples are given including rivers in Oregon and 

Washington. MULTIPLE THREATS

232. Katibah, E.F.; Dummer, K.J.; Nedeff, N.E. 1984. Current 

condition of riparian resources in the Central Valley 

of California. In: Warner, R.E.; Hendrix, K.M., eds. 

California riparian systems: Ecology, conservation, 

and productive management. Berkeley: University of 

California Press: 314-321.
44 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

Abstract: This paper describes the current condition of the 

remaining riparian resources in the Central Valley as evaluated 

with the aid of low-altitude aerial photography. A discussion 

of several factors influencing riparian resources—grazing, 

stream channelization, intra-zone and adjacent land uses—is 

presented. MULTIPLE THREATS

233. Kauffman, J.B. 1988. The status of riparian habitats 

in Pacific Northwest forests. In: Raedeke, K.J., ed. 

Streamside management: Riparian wildlife and forestry 

interactions. Institute of Forest Resources Contribution 

59. Seattle, WA: University of Washington: 45-55.

Abstract: The status of a riparian ecosystem is a value judgment and the needs of society must therefore be considered in 

ascertaining it. Management activities should vary according 

to the unique feature of the riparian zone, the desired land 

uses, and wildlife species. The management philosophy that 

will influence the future of riparian wildlife populations, 

water quality, timber production, or livestock production 

will ultimately reflect the importance of these resources to 

the citizens of the Pacific Northwest. MULTIPLE THREATS

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

on riparian ecosystems and streamside management 

implications: A review. Journal of Range Management. 

37: 431-438.

Abstract: This literature review focuses on the threats that 

livestock pose to riparian ecosystems and how management 

actions can reduce these impacts. It also discusses the importance and functions of riparian ecosystems. GRAZING

235. Kauffman, J.B.; Beschta, R.L.; Otting, N. 1997. An ecological perspective of riparian and stream restoration 

in the Western United States. Fisheries. 22(5): 12-24.

Abstract: There is an unprecedented need to preserve and 

restore aquatic and riparian biological diversity before extinction eliminates the opportunity. Ecological restoration is the 

reestablishment of processes, functions, and related biological, chemical, and physical linkages between the aquatic and 

associated riparian ecosystems; it is the repairing of damage 

caused by human activities. The first and most critical step 

in ecological restoration is passive restoration, the cessation 

of those anthropogenic activities that are causing degradation or preventing recovery. Given the capacity of riparian 

ecosystems to naturally recover, often this is all that is needed 

to achieve successful restoration. Prior to implementation of 

active restoration approaches (e.g., instream structures, channel and streambank reconfiguration, and planting programs), a 

period of time sufficient for natural recovery is recommended. 

Riparian and stream ecosystems have largely been degraded by 

ecosystem-wide, off-channel activities and, therefore, cannot 

be restored by focusing solely on manipulations within the 

channel. While ecological restoration comes at a high cost, 

it also is an investment in the natural capital of riparian and 

aquatic systems and the environmental wealth of the nation. 

MULTIPLE THREATS

236. Kaufmann, J.B.; Krueger, W.C.; Vavra, M. 1983a. Effects 

of late season cattle grazing on riparian plant communities. Journal of Range Management. 36: 685-690.

Abstract: Livestock impacts on riparian plant community 

composition, structure, and productivity were evaluated. After 3 years of comparison between fall grazed and exclosed 

(non-grazed) areas, 4 plant communities out of 10 displayed 

some significant species composition and productivity differences. Two meadow types and the Douglas hawthome 

(Crategus douglasii) community type had significant differences in standing biomass. These also were utilized more 

heavily than any other communities sampled. Shrub use was 

generally light except on willow (Salix spp.) gravel bars. 

Succession appeared to be retarded by livestock grazing on 

gravel bars. Few differences were recorded in other plant 

communities sampled, particularly those communities with 

a forest canopy. GRAZING

237. Kauffman, J.B.; Krueger, W.C.; Vavra, M. 1983b. Impacts of cattle on streambanks in Northeastern Oregon. 

Journal of Range Management. 36: 683-685.

Abstract: Impacts of a late season livestock grazing strategy 

on streambank erosion, morphology and undercutting were 

studied for 2 years along Catherine Creek in northeastern 

Oregon. Streambank loss, disturbance and undercutting were 

compared between grazing treatments, vegetation type, and 

stream-meander position. No significant differences were 

found among vegetation types or stream-meander location. 

Significantly greater streambank erosion and disturbance 

occurred in grazed areas than in exclosed areas during the 

1978 and 1979 grazing periods. Over-winter erosion was not 

significantly different among treatments. However, erosion 

related to livestock grazing and trampling was enough to 

create significantly greater annual streambank losses when 

compared to ungrazed areas. GRAZING

238. Kauffman, J.B.; Case, R.L.; Lytjen, D.; Otting, N.; 

Cummings, D.L. 1995. Ecological approaches to riparian restoration in Northeast Oregon. Restoration and 

Management Notes. 13: 12-15.

Abstract: The degradation of riparian ecosystems associated 

with the upper Snake River in Oregon and Idaho has contributed significantly to the precipitous declines of resident 

and anadromous salmonids. Given the economic, ecologic, 

and cultural importance of trout and salmon in the Pacific 

Northwest, the recovery of these ecosystems through restoration at landscape scales is necessary. This paper discusses 

the importance of understanding the inherent resilience of 

riparian vegetation to disturbances in the restoration of these 

ecosystems. MULTIPLE THREATS

239. Kay, C.E.; Chadde, S. 1991. Reduction of willow seed 

production by ungulate browsing in Yellowstone National Park. In: Clary, W.P.; McArthur, E.D.; Bedunah, 

D.; Wambolt, C.L., comp. Proceedings of the symposium 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 45

on ecology and management of riparian shrub communities; 1991 May 29-31; Sun Valley, ID. Gen. Tech. Rep. 

INT-309. Ogden, UT: U.S. Department of Agriculture, 

Forest Service, Intermountain Research Station: 92-99.

Abstract: This paper explores the impact native ungulates 

(elk, moose, mule deer, pronghorn, bighorn sheep, and bison) 

in Yellowstone National Park are having on sexual reproduction of willows. Long-term grazing exclosures were used 

to compare seed production in unbrowsed versus browsed 

willow communities. GRAZING

240. Keller, C.; Anderson, L.; Tappel, P. 1978. Fish habitat 

changes in Summit Creek, Idaho, after fencing the 

riparian area. In: Cope, O.B., ed. Proceedings of the 

forum—grazing and riparian/stream ecosystems; 1978 

Nov. 3-4; Denver, CO. Arlington, VA: Trout Unlimited: 

46-52.

Abstract: The rapid response of aquatic and riparian habitat 

to fencing is surprising. The unique environment of Summit Creek has contributed to dramatic habitat changes in 

only two growing seasons. The high water table, constant 

streamflow, deep soil, low stream gradient and moderate 

stream temperatures enabled the stream/riparian ecosystem 

to respond quickly after fencing. GRAZING

241. Kennedy, C.E. 1977. Wildlife conflicts in riparian management: Water. In: Johnson, R.R.; Jones, D.A., tech. 

coords. Importance, preservation and management of 

riparian habitat: A symposium; 1977 July 9; Tucson, 

AZ. Res. Pap. RM-43. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain 

Forest and Range Experiment Station: 52-58.

Abstract: This paper is a summary of observations of 

the need for a better understanding of the interactions of 

stream-riparian-vegetation-energy-nutrients-water production—aquatic life and terrestrial life. Most of the riparian 

ecosystem interactions have had very little attention in Arizona 

and New Mexico. MULTIPLE THREATS

242. Kennedy, L.J.; Tiller, R.L.; Stutz, J.C. 2002. Associations 

between arbuscular mycorrhizal fungi and Sporobolus 

wrightii in riparian habitats in arid Southwestern North 

America. Journal of Arid Environments. 50: 459–475.

Abstract: The objective of this study was to determine the 

extent of the interaction between AM fungi and S. wrightii by 

examining the seasonal dynamics of mycorrhizal colonization 

in roots of S. wrightii, and determining the AM fungal communities associated with S. wrightii in four different riparian 

habitats along the San Pedro River in south-east Arizona. 

Samples were collected from lower floodplains where S. 

wrightii is a component of mixed vegetation communities, 

which also include Fremont’s cottonwood, mesquite and the 

exotic saltcedar, and from upper terraces that are sacaton 

grasslands. Because many rivers of arid environments exhibit 

perennial streamflow in some stretches and intermittent 

streamflow in other reaches, both perennial and intermittent 

reaches were examined. INVASIVE SPECIES

243. Key, J.W.; Gish, M.A. 1988. Clark Canyon (Mono 

County) riparian demonstration area. In: Abell, D.L., 

coord. Proceedings of the California riparian systems 

conference: Protection, management, and restoration 

for the 1990’s; 1988 September 22-24; Davis, CA. Gen. 

Tech. Rep. PSW-110. Berkeley, CA: U.S. Department of 

Agriculture, Forest Service, Pacific Southwest Forest 

and Range Experiment Station: 127-134.

Abstract: Destabilization of meadow sections of the stream 

and the upper stream reaches contributed to an increase of 

suspended sediments, turbidity, and stream channel widening in the lower stream reaches of the Clark Canyon riparian 

demonstration area within the East Walker River sub-basin. 

Several different treatments have been implemented to (1) restore meadow riparian area to high levels of productivity, 

(2)stabilize active erosion and gully development, (3) improve 

aquatic habitat from poor to good condition, and (4) improve 

wildlife cover and downstream fish habitat. These treatments 

include changes in grazing management practices. GRAZING

244. Klebenow, D.A.; Oakleaf, R.J. 1984. Historical avifaunal changes in the riparian zone of the Truckee 

River, Nevada. In: Warner, R.E.; Hendrix, K.M., eds. 

California riparian systems: Ecology, conservation, 

and productive management. Berkeley: University of 

California Press: 203-209.

Abstract: Comparisons of populations of the present avifauna 

with observations made during 1868 along the lower Truckee 

River show species changes in abundance. The most noticeable changes in the avifauna involved species that require 

dense understory of woody riparian vegetation, wet meadow, 

and marsh. Numerous species have declined in abundance; 

many not found in recent counts were abundant or common 

in 1868. The apparent population decline can be related to the 

compounding effects of farmland development, river channeling operations, and overgrazing. MULTIPLE THREATS

245. Knight, A.W.; Bottorff, R.L. 1984. The importance of 

riparian vegetation to stream ecosystems. In: Warner, 

R.E.; Hendrix, K.M., eds. California riparian systems: 

Ecology, conservation, and productive management. 

Berkeley: University of California Press: 160-167.

Abstract: Riparian vegetation is very important in determining the structure and function of stream ecosystems. The 

manner in which riparian systems are managed and protected 

is commonly related to their value as buffer strips, stream 

bank stabilizers, and fish and wildlife habitat. These strips of 

streamside vegetation may be the only habitat remaining for 

some wildlife species. As riparian vegetation is modified or 

destroyed by grazing, logging, urbanization, road construction, water development, mining and recreation, interest in 
46 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

its importance is increasing. The objective of this paper is to 

briefly review the role of riparian vegetation in the structure 

and function of stream ecosystems, especially headwater 

streams. MULTIPLE THREATS

246. Knight, R.L. 1988. Relationships of birds of prey and 

riparian habitat in the Pacific Northwest: An overview. 

In: Raedeke, K.J., ed. Proceedings of the Southwest 

raptor management symposium; Washington, DC: 

National Wildlife Federation: 79-91.

Abstract: This paper presents a review of information on 

raptor communities: nesting, foraging, nocturnal roosting, 

seasonal use, and the effects of human perturbations (e.g. 

logging, recreational activities). It also discusses management 

practices used to mitigate conflicts between human and raptor 

uses of riparian zones. MULTIPLE THREATS

247. Knopf, F.L. 1986. Changing landscapes and the cosmopolitism of the eastern Colorado avifauna. Wildlife 

Society Bulletin. 14: 132-142.

Abstract: The development of a riparian forest on the Great 

Plains has provided a corridor for the movement of forest 

birds across those grasslands that have historically served 

as an ecological barrier to dispersal. Almost 90% of the 

contemporary avifauna of northeastern Colorado was not 

present at the turn of the century. The corridor has resulted 

in secondary contact of many congeneric species, which 

currently hybridize on the Great Plains; the hybridization 

may be interpreted either as reversing 10,000 years of speciation, or alternatively as promoting hybrid vigor within. 

INVASIVE SPECIES

248. Knopf, F.L. 1986. Wildlife considerations in seasonal 

grazing of riparian zones. In: Smits, J.H., ed. Management of riparian areas. Washington, DC: Public Lands 

Council: 39-40.

Abstract: This paper concludes that 10 to 12 years is insufficient time for a riparian community to recover from a history 

of excessive grazing. While fish habitats respond quickly to 

changes in grazing practices, terrestrial communities take 

considerably longer. GRAZING

249. Knopf, F.L. 1988. Riparian wildlife habitats: More, 

worth less, and under invasion. In: Mutz, K.M.; Cooper, 

D.J; Scott, M.L.; Miller, L.K., tech. coords. Restoration, creation and management of wetland and riparian ecosystems in the American West: Proceedings 

of a symposium; 1988 November 14-16; Denver, CO. 

Boulder, CO: Society of Wetland Scientists, Rocky 

Mountain Chapter: 20-22.

Abstract: This paper gives a general overview of riparian 

ecosystems in the American West, the potential conflicts 

these systems face, and how they have changed over time. 

MULTIPLE THREATS

250. Knopf, F.L.; Cannon, R.W. 1982. Structural resilience of 

a willow riparian community to changes in grazing practices. In: Wildlife livestock relationships symposium: 

Proceedings 10. Moscow, ID: University of Idaho Forest, Wildlife, and Range Experiment Station: 198-207.

Abstract: The objective of this study was to quantify the 

impact of cattle on the physical structure of a high-altitude 

willow community in Colorado. The willow community tolerated heavy grazing pressures well initially, but recovered 

slowly when damaged. GRAZING

251. Knopf, F.L. and T.E. Olson. 1988. Naturalization of 

Russian-olive: Implications to Rocky Mountain wildlife. 

Wildlife Society Bulletin. 12: 289-298.

Abstract: This paper (1) alerts natural resource conservation personnel to naturalization of Russian-olive in the West, 

(2) reports on the avian and mammalian associations of 

monotypic stand of Russian-olive in three western States, 

(3) discusses similarities of those associations to vertebrate communities occurring in nearby native riparian and 

upslope vegetation types using an analytical approach, 

and (4) speculates on implications of the continued naturalization of Russian-olive to Rocky Mountain avian and 

mammalian communities. INVASIVE SPECIES

252. Knopf, F.L.; Sedgwick, J.A.; Cannon, R.W. 1988. Guild 

structure of a riparian avifauna relative to seasonal cattle 

grazing. Journal of Wildlife Management. 52: 280-290.

Abstract: The avifauna within the willow community on 

the Arapaho National Wildlife Refuge was dominated by 11 

species of passerine birds during the summers of 1980-1981. 

Population densities of the eurytopic response guild differed little between healthy (historically winter-grazed) and 

decadent willow communities (historically summer-grazed) 

within a year. Densities of species in the mesotopic response 

guild differed more dramatically, and stenotopic responseguild species were absent or accidental in decadent willows. 

The authors hypothesize that the response-guild structure 

primarily reflects the impact of cattle upon the horizontal 

patterning of the vegetative community. GRAZING

253. Knopf, F.L.; Johnson, R.R.; Rich, R.; Samson, F.B.; 

Szaro, R.C. 1988. Conservation of riparian ecosystem 

in the United States. Wilson Bulletin. 100: 289-298.

Abstract: This paper describes two potential dangers in 

developing management policy based on a site-specific 

information, viewed from a national perspective: (1) local 

information can foster erroneous conclusions regarding 

the biological contribution of a specific association to the 

continental avifauna; and (2) the tendency to view sitespecific data as finite, bounded information. MULTIPLE 

THREATS
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 47

254. Knudsen, A.B.; Johnson, R.; Johnson, K.; Henderson, 

N.R. 1977. A bacteriological analysis of portable toilet 

effluent at selected beaches along the Colorado River, 

Grand Canyon National Park, Arizona. In: Proceedings of river recreation management and research 

symposium; 1977 January 24-27; Minneapolis, MN. 

Gen. Tech. Rep. NC-28. St. Paul, MN: U.S. Department 

of Agriculture, Forest Service, North Central Forest 

Experiment Station: 290-295.

Abstract: Portable toilet effluent buried at nine beaches 

along the Colorado River, Grand Canyon National Park, 

Arizona, was examined. Viable total and fecal coliforms 

were isolated 84 percent of the time. Organisms migrated 

up to 8 inches away from the burial sites at 22 percent of 

the beach locations. Coliforms were present throughout the 

strata to a depth of 2 feet. No direct relationship was evident 

when comparing percent soil moisture, percent coarse sand, 

and numbers of organisms. Ground temperatures directly 

affected the numbers of organisms present. A definite public 

health hazard is seen in the numbers of coliforms and associated organisms surviving from one season to the next. 

RECREATION

255. Konopacky, R.C.; Bowles, E.C.; Cernera, P.J. 1985. 

Salmon River habitat enhancement: Annual report FY 

1984. Project No. 83-359. Portland, OR: U.S. Department 

of Energy, Bonneville Power Administration, Division 

of Fish and Wildlife.

Abstract: The objectives of this study were (1) to determine 

the feasibility of enhancing anadromous fish habitat, and (2) to 

evaluate effects of habitat enhancement on the habitat and fish 

community in various reaches of the Salmon River in Idaho, 

where increased sedimentation caused by mining activities 

had resulted in degradation of the aquatic habitat. MINING

256. Konopacky, R.C.; Cernera, P.J.; Bowles, E.C.; Montgomery, J.M. 1986. Salmon River Habitat Enhancement: 

Annual Report FY 1985. Project No. 83-359. Portland, 

OR. U.S. Department of Energy, Bonneville Power 

Administration, Division of Fish and Wildlife. 445p.

Abstract: This study evaluates the effects of habitat enhancement on the habitat and fish community in various reaches of 

the Salmon River in Idaho, where increased sedimentation 

caused by mining activities had caused degradation of the 

aquatic habitat. In particular the Bear Valley Creek (Middle 

Fork Salmon River), Yankee Fork Salmon River, and East 

Fork Salmon River/Herd Creek were evaluated. MINING

257. Korte, N.; Kearl, P.; Koehler, D. 1993. Strategies to define 

and implement large-scale watershed restoration project 

policy on the Navajo Nation. In: Tellman, B.; Cortner, 

H.J.; Wallace, M.G.; DeBano, L.F.; Hamre, R.H., tech. 

coords. Riparian management: Common threads and 

shared interests. A western regional conference on river 

management strategies; 1993 Feb 4-6; Albuquerque, 

NM. Gen. Tech. Rep. RM-226. Fort Collins, CO: U.S. 

Department of Agriculture Forest Service, Rocky Mountain Forest and Range Experiment Station: 198-202.

Abstract: Typical effects of poor land-management practices 

on riparian zones are evident throughout the Navajo Nation. 

After many years (50-100 or more) of overgrazing by livestock, 

the original riparian vegetation is gone. For a restoration 

project to have lasting beneficial effects, the tribe has to be 

an active participant. Examples of training, experience, and 

additional research needs are given in this paper. GRAZING

258. Kovalchik, B.L. 1991. Growth and yield of willows in 

central Oregon compared to reports in world literature. 

In: Clary, W.P.; McArthur, E.D.; Bedunah, D.; Wambolt, 

C.L., comps. Proceedings of the symposium on ecology 

and management of riparian shrub communities; 1991 

May 29-31; Sun Valley, ID. Gen. Tech. Rep. INT-309. 

Ogden, UT: U.S. Department of Agriculture, Forest 

Service, Intermountain Research Station: 83-88

Abstract: Many willow dominated sites have been degraded 

to less stable plant communities in response to improper 

management activities such as overuse by livestock. This 

paper summarizes world literature on willow growth and 

compares the information with willow growth in central 

Oregon. GRAZING

259. Kovalchik, B.L.; Elmore, W. 1991. Effects of cattle grazing systems on willow dominated plant associations 

in central Oregon. In: Clary, W.P.; McArthur, E.D.; 

Bedunah, D.; Wambolt, C.L. comp. Proceedings of the 

symposium on ecology and management of riparian 

shrub communities; 1991 May 29-31; Sun Valley, ID. 

Gen. Tech. Rep. INT-309. Ogden, UT: U.S. Department 

of Agriculture, Forest Service, Intermountain Research 

Station: 111-119.

Abstract: Improper cattle grazing has severely affected the 

stability of riparian zones, especially those once dominated by 

willows. The authors reviewed willow literature and combined 

pertinent information with experience and described grazing 

system effects on willow-dominated plant associations in 

central Oregon. GRAZING

260. Kranjcec, J.; Mahoney, J.M.; Rood, S.B. 1998. The responses 

of three riparian cottonwood species to water table decline. 

Forest Ecology and Management. 110: 77-87.

Abstract: The present study demonstrates that tolerance to 

water table decline varies across cottonwood genotypes and 

that Populus balsamifera saplings were the most vigorous. 

This is relevant to the natural distribution in which P. balsamifera occurs in mountain regions where stream stages 

and riparian water table depths often change abruptly. The 

vigor of P. balsamifera is also consistent with the reproductive mechanism of “branch propagation,” a process of clonal 
48 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

recruitment in which browsed or broken branch fragments 

root along stream edges, enabling dispersive propagation, 

particularly of P. balsamifera and P. trichocarpa.GROUNDWATER DEPLETION, DROUGHT

261. Kriegshauser, D.; Somers, P. 2004. Vegetation changes 

in a riparian community along the Dolores River 

downstream from McPhee reservoir in southwestern 

Colorado. In: van Riper III, C.; Cole, K.L., eds. The 

Colorado Plateau: Cultural, biological and physical 

research. Tucson, AZ: The University of Arizona Press: 

129-137.

Abstract: This paper describes the long-term study, which 

was undertaken to determine whether, and to what extent, a 

regime of low, constant river flow would affect a set of riparian communities of various ages and composition. WATER 

DIVERSION

262. Krueper, D.J. 1992. Effects of land use practices on 

western riparian ecosystems. In: Finch, D.M.; Stangel, 

P.W., eds. Status and management of neotropical 

migratory birds; 1992 September 21-25; Estes Park, CO: 

Gen. Tech. Rep. RM-229. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain 

Forest and Range Experiment Station: 321-330.

Abstract: This paper reviews impacts to Western United 

States riparian ecosystems along with mitigation and conservation recommendations for resource managers. MULTIPLE 

THREATS

263. Krueper, D.J. 1996. Effects of livestock management 

on Southwestern riparian ecosystems. In: Shaw, D.W.; 

Finch, D.M., tech. coords. Desired future conditions for 

southwestern riparian ecosystems: Bringing interests 

and concerns together. Gen. Tech. Rep. RM-272. Fort 

Collins, CO: U.S. Department of Agriculture, Forest 

Service, Rocky Mountain Forest and Range Experiment 

Station: 328-301.

Abstract: Within the past 100 years, an estimated 95% 

of the riparian habitat in western North America has been 

altered, degraded, or destroyed due to a wide variety of 

land use practices such as river channelization, clearing for 

agriculture, livestock grazing, water impoundments, and 

urbanization. This has resulted in negative impacts on native 

wildlife population including insects, fish, reptiles, amphibians, birds, and mammals. The importance of riparian habitats 

and the negative impacts to the native wildlife are described 

in this paper. GRAZING

264. Lacy, M.; Stuart, A.; Smith, B. 1985. John Day River 

enhancement: Annual Progress Report FY 1985. 

In: Natural propagation and habitat enhancement, 

Volume I—Oregon. Project No. 84-21. Portland, OR: 

U.S. Department of Energy, Bonneville Power Administration, Division of Fish and Wildlife: 212-221.

Abstract: A variety of man’s activities have impacted salmon 

and steelhead habitat in the John Day River system in Oregon. 

Dredging, overgrazing, road building, logging, landowner 

clearing, increased water withdrawals, and channelization 

created further fish habitat problems by disturbing or destroying riparian vegetation and destabilizing streambanks 

and watersheds. The purpose of the in-stream and riparian 

restoration work described in this report is to maintain wild 

gene pools and enhance production of smelts and adults. 

MULTIPLE THREATS

265. Lafayette, R.A.; Pruitt, J.R.; Zeedyk, W.D. 1992. Riparian area enhancement through road design and maintenance. In: Neary, D.G.; Ross, K.C.; Coleman, S.S., 

eds. Proceedings of the national hydrology workshop; 

1992 April 27- May 1; Phoenix, AZ. Gen. Tech. Rep. 

RM-279. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and 

Range Experiment Station: 85-95.

Abstract: This paper has several main objectives: (1) present 

a historical perspective on road-related impacts on riparian 

areas in the Southwest, (2) discuss how these impacts were 

recognized and analyzed, (3) list typical problems associated 

with road/riparian conflicts, (4) present suggested solutions, 

and methods to avoid future problems or correct existing ones, 

and (5) discuss program progress to date and likely future 

accomplishments. ROADS

266. Lambert, D.J.; Hannon, S.J. 2000. Short-term effects of 

timber harvest on abundance, territory characteristics, 

and pairing success of Ovenbirds in riparian buffer 

strips. The Auk. 117(3): 687–698.

Abstract: In managed forests, riparian buffer strips typically 

are maintained to protect water quality. If properly designed, 

buffer strips also may act as wildlife reserves. However, forest 

managers have lacked the information to develop standards 

for buffer strips to maximize benefits for wildlife species. 

This study assessed the conservation potential of 20-, 100-, 

and 200-m wide buffers for an area-sensitive songbird in 

boreal mixed-wood forest in Alberta. The authors measured 

abundance, territory characteristics, and pairing success of 

Ovenbirds (Seiurus aurocapillus) at treatment and control 

lakes one year before and after upland timber harvest. The 

data indicate that 20-m buffer strips do not support breeding 

Ovenbirds, whereas 100- and 200-m buffers retain Ovenbirds 

during the year following harvest. FOREST HARVESTING

267. Larsen, R.E.; Krueger, W.C.; George, M.R.; Barrington, 

M.R.; Buckhouse, J.C.; Johnson, D.E. 1998. Viewpoint: 

Livestock influences on riparian zones and fish habitat: 

Literature classification. Journal of Range Management. 

51: 661-664.

Abstract: This study used a key to classify articles about 

livestock influences on riparian zones and fish habitat into 

3 classes: papers that contained original data, those that 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 49

were commentary, and reports about methodology such as 

classification systems, policies, and monitoring criteria. 

Four hundred and twenty-eight of the total articles were 

directly related to grazing impacts on riparian zones and 

fish habitat. Only 89 of these grazing impact articles were 

classified as experimental, where treatments were replicated 

and results were statistically valid. This analysis revealed 

several limitations of riparian grazing studies: (1) inadequate 

description of grazing management practices or treatments, 

(2) weak study designs, and (3) lack of pre-treatment data. 

More long-term, replicated treatment studies are needed in 

the future. GRAZING

268. Leal, D.A.; Meyer, R.A.; Thompson, B.C. 1996. Avian 

community composition and habitat importance in the 

Rio Grande corridor of New Mexico. In: Shaw, D.W.; 

Finch, D.M., tech. coords. Desired future conditions for 

southwestern riparian ecosystems: Bringing interests 

and concerns together. Gen. Tech. Rep. RM-272. Fort 

Collins, CO: U.S. Department of Agriculture, Forest 

Service, Rocky Mountain Forest and Range Experiment 

Station: 62-68.

Abstract: Generally, avian communities preferred cottonwood and other native woody species as dominants over those 

that are highly manipulated and/or monotypic, such as mowed 

river edge, pecan orchards, and pure stands of saltcedar. 

Bird occurrence and distribution in the Rio Grande corridor 

is not so neatly related to composition of native vegetation 

as is sometimes characterized. Exotic plant species, such as 

saltcedar and Russian olive, are utilized to varying degrees 

by the existing avian community. INVASIVE SPECIES

269. Leonard, S.; Kinch, G.; Elsbernd, V.; Borman, M.; 

Swanson, S. 1997. Riparian area management: Grazing management for riparian-wetland areas. Technical 

Reference 1737-14. Denver, CO: U.S. Department of the 

Interior, Bureau of Land Management: 63 p.

Abstract: Depending on condition and potential, riparian 

areas usually respond more quickly than drier upland ranges 

to changes in grazing management. This document presents 

information from various land managers and researchers to 

guide livestock management in riparian areas using their 

unique responsiveness to accomplish management objectives. GRAZING

270. Lesica, P.; Miles, S. 2004. Ecological strategies for managing tamarisk on the C.M. Russell National Wildlife 

Refuge, Montana, USA. Biological Conservation. 119: 

535–543.

Abstract: The purpose of this study was to provide descriptions of habitats and geomorphologic settings threatened by 

tamarisk invasion. Knowing which stands can be killed by 

inundation and which stands most threaten native biological 

diversity will aid managers in planning integrated tamarisk 

management. Specifically this study (1) determines the types 

of vegetation in which tamarisk occurs or is likely to occur, 

(2) provides information on the age of tamarisk stands and how 

they are likely to alter native plant communities, (3) develops 

criteria for managers on how to identify stands that are most 

likely to adversely affect native plant communities and the 

biological diversity they support, and (4) determines which 

hydrologic regimes destroy tamarisk at which elevations. 

INVASIVE SPECIES

271. Lewis, D.E.; Marsh, G.G. 1977. Problems resulting 

from the increased recreational use of rivers in the 

west. In: Proceedings of river recreation management 

and research symposium; 1977 January 24-27; Minneapolis, MN. Gen. Tech. Rep. NC-28. St. Paul, MN: 

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

Central Forest Experiment Station: 27-31.

Abstract: This paper discusses impacts and conflicts created 

by increasing recreation use of rivers in the western United 

States. Problems addressed include environmental, social, and 

administrative interrelationships on rivers. RECREATION

272. Lite, S.J.; Stromberg, J.C. 2005. Surface water and 

ground-water thresholds for maintaining PopulusSalix forests, San Pedro River, Arizona. Biological 

Conservation. 125: 153–167.

Abstract: The purpose of this study was to (1) identify hydrologic thresholds for maintaining Populus fremontii-Salix. 

gooddingii forests; (2) quantify changes in P. fremontii, S. 

gooddingii, and Tamarix ramosissima population stand 

structure traits (size class diversity, canopy cover, basal 

area, vegetation volume, and stem density) across gradients 

of ground-water depth and fluctuation and surface flow permanence; and (3) assess how community composition and 

biomass structure vary across these hydrologic gradients. 

GROUNDWATER DEPLETION, INVASIVE SPECIES

273. Livingston, M.F.; Schemnitz, S.D. 1996. Summer bird/

vegetation associations in Tamarisk and native habitat 

along the Pecos River, southeastern New Mexico. In: 

Shaw, D.W.; Finch, D.M., tech. coords. Desired future 

conditions for southwestern riparian ecosystems: 

Bringing interests and concerns together. Gen. Tech. 

Rep. RM-272. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 171-180.

Abstract: This paper describes research that is part of a longterm study investigating hydrological and wildlife response to 

tamarisk removal on the Pecos River in New Mexico. Factors 

including vegetation structure, grazing, habitat patchiness, 

and human disturbance are offered to explain differences in 

bird community pattern between sites. INVASIVE SPECIES

274. Loper, D.; Sun, D.; Taliaferro, B. 1987. Rancher initiated 

riparian management along the Oregon Trail. In: Mutz, 

K.M.; Lee, L.C., tech. coords. Wetland and riparian 
50 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

ecosystems of the American West: Proceedings of 

the eighth annual meeting of the Society of Wetland 

Scientists. 1987 May 26-29; Seattle WA. Denver, CO: 

Planning Information Corp.: 276-279.

Abstract: Riparian areas along the Oregon Trail were, historically, overused and abused. Many of these areas have been 

improving and can improve even more through sound ranch 

management. The Sun Ranch and the Green River Ranch and 

Livestock Company are using in-stream structures to raise 

the water level within creeks on their ranches. GRAZING

275. Lucas, R.W.; Baker, T.T.; Wood, M.K.; Allison, C.D.; 

Vanleeuwen, D.M. 2004. Riparian vegetation response 

to different intensities and seasons of grazing. Journal 

of Range Management. 57: 466-474.

Abstract: This study, in the Black Range of western New 

Mexico, compared effects of different seasons of use (cool 

season, warm season, and dormant season) and grazing 

intensities (light, moderate, and none) of cattle on young 

narrowleaf cottonwood populations, and herbaceous vegetation in two adjacent southwestern riparian areas. The authors 

concluded that no single riparian area management approach 

is best in all situations, but the grazing treatments used in this 

study appear to have been successful at maintaining riparian 

communities. GRAZING

276. Mahoney, D.L.; Erman, D.C. 1984. The role of streamside 

bufferstrips in the ecology of aquatic biota. In: Warner, 

R.E.; Hendrix, K.M., eds. California riparian systems: 

Ecology, conservation, and productive management. 

Berkeley: University of California Press: 168-176.

Abstract: Riparian vegetation is important as a source of food 

to stream organisms, as shade over small-order streams, and 

as a bank-stabilizing force to prevent excessive sedimentation 

and to intercept pollutants. Logging may significantly affect 

each of these factors unless proper protective measures are 

employed. Analysis of algal samples from 30 streams shows 

light intensity and chlorophyll concentrations are major factors related to legging intensity that affect instream primary 

production. Transportable sediment from 24 streambeds has 

shown that this measure of sediment is higher in logged and 

narrow buffered streams than in controls 7 to 10 years after 

logging. FOREST HARVESTING

277. Malmqvist, B.; Rundle, S. 2002. Threats to the running 

water ecosystems of the world. Environmental Conservation. 29(2): 134-153.

Abstract: This paper reviewed long-term trends that currently 

impact running waters with the aim of predicting what the 

main threats to rivers will be in the year 2025. The main 

ultimate factors forcing change in running waters, such as 

ecosystem destruction, physical habitat, and water chemistry 

alteration, direct addition or removal of species, stem from 

proximate influences from urbanization, industry, land-use 

change, and water-course alterations. MULTIPLE THREATS

278. Manci, K.M. 1989. Riparian Ecosystem Creation and 

Restoration: A Literature Summary. U.S. Fish and 

Wildlife Biological Report 89(20). Fort Collins, CO: 

U.S. Department of the Interior, Fish and Wildlife 

Service: 59 p.

Abstract: This summary provides an overview of the status 

of riparian ecosystems in the United States. Case studies of 

various riparian ecosystem creation or restoration projects are 

used to demonstrate various techniques and to report some 

results of their use. MULTIPLE THREATS

279. Manning, R.E. 1979. Impacts of recreation on riparian 

soils and vegetation. Water Resources Bulletin. 15: 

30-43.

Abstract: The magnetic attraction of water resources for 

recreation has direct implications for land resources that are 

needed to provide access and support facilities. This paper 

reviews and synthesizes the literature dealing with the impacts 

of recreation use on riparian soils and vegetation. Part one of 

the paper sets forth the major negative impacts of recreation 

use on soils and vegetation. A seven-step soil impact cycle is 

identified, beginning with the scuffing away of leaf litter and 

other organic material and working through the soil erosion 

and sedimentation process. Four major kinds of impacts of 

recreation use on vegetation are then outlined, and the relationship between impacts on soil and vegetation is demonstrated. 

Part two identifies several spatial and temporal patterns of 

environmental impact caused by recreation use. The node 

and linkage pattern of recreation use, campground and trail 

expansion, ground cover response and succession, rates of 

soil compaction, and resource response to various intensities 

of recreation use are important aspects. The final part of the 

paper deals with measuring environmental impacts caused 

by recreation use. Management implications of the research 

findings are considered throughout the paper. RECREATION

280. Marcus, L. 1988. Riparian reforestation and watershed 

management: Some examples from the California Coast. 

In: Abell, D.L., coord. Proceedings of the California 

riparian systems conference: Protection, management, 

and restoration for the 1990’s; 1988 September 22-24; 

Davis, CA; Gen. Tech. Rep. PSW-110. Berkeley, CA: 

U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station: 

204-210.

Abstract: Managing and restoring watersheds often involves 

re-creation of riparian habitats. Examples from rural and urban 

areas illustrate how riparian restoration can be integrated into 

watershed projects. MULTIPLE THREATS

281. Marlow, C.B.; Pogacnik, T.M. 1986. Cattle feeding and 

resting patterns in a foothills riparian zone. Journal of 

Range Management. 39: 212-217.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 51

Abstract: Cattle impact on riparian areas is dependent upon 

both their behavior and utilization of streamside vegetation. 

Development of grazing strategies for riparian environments 

would be enhanced by an understanding of cattle behavior in 

riparian and adjacent uplands. Results of a 2-year behavior 

study indicate that a seasonal trend in cattle use of riparian 

and upland areas exists. GRAZING

282. Marlow, C.B.; Olson-Rutz, K.; Atchley, J. 1989. Response 

of a southwestern Montana riparian system to four 

grazing management alternatives. In: Gresswell, R.E.; 

Barton, B.A.; Kershner, J.L., eds. Practical approaches 

to riparian resource management: An educational workshop; 1989 May 8-11; Billings, MT. U.S. Department 

of the Interior, Bureau of Land Management: 111-116.

Abstract: The effects of deferred rotation, time-control, 

season-long and livestock exclusion on streambank stability 

and trout habitat condition in a southwestern Montana riparian 

zone has been monitored for 3 years. Decreasing the length 

of time cattle have access to a stream reach and adjusting 

the grazing period to coincide with low streambank moisture 

levels shows promise for the improvement of riparian zone 

conditions. GRAZING

283. Marnell, L.F. 1995. Cutthroat trout in Glacier National 

Park, Montana. In: LaRoe, E.T.; Farris, G.S.; Puckett, 

C.E.; Doran, P.D.; Mac, M.J., eds. Our living resources: 

A report to the nation on the distribution, abundance, 

and health of U.S. plants, animals, and ecosystems. 

Washington, DC: U.S. Department of the Interior, 

National Biological Service: 153-154.

Abstract: The introduction and entry of non-native species to 

the indigenous fishery of Glacier National Park has radically 

altered the park’s pristine condition. The non-native species 

introduction has adversely affected the native westslope cutthroat trout. Effects of fish introductions in Glacier National 

Park include establishment of non-native trout populations 

in historically fishless waters, genetic contamination and 

ecological interferences with various life-history stages of 

native trout. INVASIVE SPECIES

284. Martin, D.W.; Chambers, J.C. 2001. Restoring degraded 

riparian meadows: Biomass and species responses. 

Journal of Range Management. 54: 284-291.

Abstract: Riparian meadows in central Nevada are highly 

productive and have been extensively utilized for livestock 

grazing. Consequently, many have been severely degraded 

resulting in changes in species composition and decreases in 

productivity. During a 3-year study, the authors examined the 

responses of mesic meadow systems to yearly nitrogen addition and clipping to increase their understanding of grazing 

effects. They also examined the effects of a one-time, fall 

aeration and revegetation (removal of existing vegetation and 

reseeding) to evaluate the restoration potential of these sites. 

Changes in total biomass, species aerial cover and frequency, 

and surface basal cover were used to evaluate treatment 

responses. The results were influenced by high spatial and 

temporal variability in water table elevations. GRAZING

285. Martin, K.E. 1984. Recreation planning as a tool to 

restore and protect riparian systems. In: Warner, R.E.; 

Hendrix, K.M., eds. California riparian systems: 

Ecology, conservation, and productive management. 

Berkeley: University of California Press: 748-757.

Abstract: This paper examines planning strategies that assure 

the protection of riparian systems from recreationists while 

providing for recreation use. A riparian forest adjacent to a 

densely populated area and subject to intensive recreation use 

is investigated. The popular recreation activities that occur in 

connection with a riparian system are identified and methods 

for controlling recreation use are discussed. RECREATION

286. Martin, S.B.; Platts, W.S. 1981. Effects of mining: Influence of forest rangeland management on anadromous 

fish habitat in western North America. Gen. Tech. 

Rep. PNW-119. Portland, OR: U.S. Department of 

Agriculture, Forest Service, Pacific Northwest Forest 

and Range Experiment Station: 15 p.

Abstract: This report describes the methods of mining and 

the effects on aquatic ecosystems of mine-caused sediment, 

changes in pH, and toxic heavy metals. MINING

287. Martin, S.C. 1978. Evaluating the impact of cattle grazing 

on riparian habitats in the national forests of Arizona 

and New Mexico. In: Cope, O.B., ed. Proceedings of 

the forum—grazing and riparian/stream ecosystems; 

1978 Nov. 3-4; Denver, CO. Arlington, VA: Trout 

Unlimited: 35-38.

Abstract: The objective of this paper is to determine when 

and where cattle are least likely to damage riparian sites, 

and to assess the feasibility of reducing damage by changing 

schedules of grazing, developing additional livestock waters, 

or by other range-management practices. GRAZING

288. Masters, L.S.; Burkhardt, J.W.; Tausch, R. 1991. The 

geomorphic process: Effects of base level lowering 

on riparian meadow communities. Rangelands. 13: 

280-284.

Abstract: The drying of the Pleistocene lakes has resulted in 

widespread downcutting and headward erosion that is continuing throughout watersheds in the Great Basin. However, 

this knowledge has largely been ignored or overlooked. It is 

important to recognize and understand these relationships so 

that responsible management decisions can be made. Removing or reducing domestic livestock from a meadow will not 

prevent the loss of that valuable land, if the more dominant 

erosion processes associated with base-level adjustments are 

driving current stream channel changes. Climatically driven 

lake level changes, crustal tectonics, or man-made channel 

alterations produce similar results. Road construction, bridge 
52 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

and culvert installation, reservoirs and water diversions, channelizing, and revetment projects can all affect local stream 

base levels and initiate subsequent upstream and downstream 

channel adjustments. MULTIPLE THREATS

288. Masters, R.A.; Sheley, R.L. 2001. Principles and practices for managing rangeland invasive plants. Journal 

of Range Management. 54: 502-517.

Abstract: Invasive plants reduce the capacity of ecosystems 

to provide goods and services required by society, alter ecological processes, and can displace desirable species. They 

can reduce wildlife habitat quality, riparian area integrity, 

rangeland economic value, and enterprise net returns. The 

invasion process is regulated by characteristics of the invading 

plant and the community being invaded. The presence and 

spread of invasive plants is often symptomatic of underlying 

management problems that must be corrected before acceptable, long-term rangeland improvement can be achieved. 

Invasive plant management programs must be compatible with 

and integrated into overall rangeland resource management 

objectives and plans. Because of the complexity of managing invasive plants, it is imperative that relevant ecological 

and economic information be synthesized into user-friendly 

decision support systems. INVASIVE SPECIES, GRAZING

289. McCormick, F.H.; Contreras, G.C.; Johnson, S.L. 

2009. Effects of non-indigenous invasive species on 

water quality and quantity. In: Dix, M.E.; Britton, K., 

eds. A dynamic invasive species research vision: Opportunities and priorities 2009-2029. Gen. Tech. Rep. 

WO-GTR-79/83. Washington, DC: U.S. Department 

of Agriculture, Forest Service, Research and Development: 111-120.

Abstract: This paper identifies desired resource outcomes, 

addresses management strategies and systems needed to 

achieve the outcomes, discusses potential effects on riparian systems and water resources, and identifies research and 

actions needed to achieve the desired outcomes. INVASIVE 

SPECIES

290. McCluskey, D.C.; Brown, J.; Bornholdt, D.; Duff, D.A.; 

Winward, A.H. 1983. Willow planting for riparian 

habitat improvement. Tech. Note 363. Washington, 

DC: U.S. Department of the Interior, Bureau of Land 

Management: 21 p.

Abstract: This report is designed for field personnel who 

are interested in employing willow planting as a technique 

for riparian habitat improvement. MULTIPLE THREATS

291. McGuire, J.R. 1978. A riparian policy for changing 

times. In: Johnson, R.R.; McCormick, J.F., tech. coords. 

Strategies for protection and management of floodplain 

wetlands and other riparian ecosystems. Gen. Tech. 

Rep. WO-12. Washington, DC: U.S. Department of 

Agriculture, Forest Service: 341-343.

Abstract: The Forest Service recognizes the importance 

and unique values of riparian ecosystems, and the increasing 

public awareness of these values. Policy directions state that 

these lands on the National Forest System will be managed 

for their unique values, following the principles of multiple 

use and sustained yield, and meeting stewardship responsibilities for protecting soil, water, and vegetative resources.

MULTIPLE THREATS

292. McInnis, M.L.; McIver, J. 2001. Influence of off-stream 

supplements on streambanks of riparian pastures. 

Journal of Range Management. 54: 648-652.

Abstract: Accelerated erosion of streambanks in grazed riparian pastures is of concern to land managers. We tested the 

hypothesis that providing cattle free-choice off-stream water 

and trace mineralized salt would lessen negative impacts of 

grazing on cover and stability of streambanks compared to 

pastures lacking these amenities, and may therefore reduce 

the potential of accelerated erosion. The study was conducted 

on Milk Creek at the Hall Ranch Unit of the Eastern Oregon 

Agricultural Research Center near Union, Oregon. Three 

replications each of three grazing treatments were examined: 

(1) non-grazed control, (2) grazed with supplemental water 

and trace mineralized salt provided, and (3) grazed with no 

supplemental water or salt. GRAZING

293. McKinstery, M.C.; Hubert, W.A.; Anderson, S.H. 2004. 

Wetland and riparian areas of the Intermountain West: 

Ecology and management. Austin TX: University of 

Texas Press: 319 p.

Abstract: This book consists of twelve articles, which 

examine issues ranging from laws and regulations affecting habitats, to the unique physiographic features of the 

region, the importance of wetlands and riparian areas to 

fish, wildlife, and livestock, the ecological function of these 

areas, and their value to humans and the methods to evaluate 

these habitats. The authors also address the human impacts 

on the land from urban and suburban development, mining, 

grazing, energy extraction, recreation, water diversion, and 

timber harvesting, and suggest ways to mitigate such impacts. 

MULTIPLE THREATS

294. McNatt, R. 1978. Possible strategies for preservation of 

the San Pedro River riparian community. In: Johnson, 

R.R.; McCormick, J.F., tech. coords. Strategies for 

protection and management of floodplain wetlands 

and other riparian ecosystems. Gen. Tech. Rep. WO12. Washington, DC: U.S. Department of Agriculture, 

Forest Service: 201-206.

Abstract: Because of the scarcity of riparian habitat in 

Arizona and its obvious importance to fish and wildlife, the 

U.S. Fish and Wildlife Service is investigating methods to 

preserve remaining riparian areas along the San Pedro River 

in southeast Arizona. Possible strategies include acquisition 

under the Unique Ecosystem program, enactment of local 

ordinances, and State-wide legislation. MULTIPLE THREATS
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 53

295. Medin, D.E.; Clary, W.P. 1989. Small mammal populations in a grazed and ungrazed riparian habitat in Nevada. Res. Pap. INT-413. Ogden, UT: U.S. Department 

of Agriculture, Forest Service, Intermountain Forest 

and Range Experiment Station: 6 p.

Abstract: This paper compares community composition and 

the relative abundance of small mammal populations between 

a riparian habitat grazed by cattle and a comparable adjacent 

exclosure on the West Fork of Deer Creek in northeastern 

Nevada. GRAZING

296. Medina, A.L. 1996. Native aquatic plants and ecological 

condition of southwestern wetlands and riparian areas. 

In: Shaw, D.W.; Finch, D.M., tech. coords. Desired future conditions for southwestern riparian ecosystems: 

Bringing interests and concerns together. Gen. Tech. 

Rep. RM-272. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 329-335.

Abstract: Research on montane wetland and riparian systems 

has shown the relative importance of native aquatic plants 

in maintaining the systems in a functional condition. The 

presence or absence of key species is used as an indicator 

of ecological condition, and desired ecological condition of 

composition and abundance of native aquatic plants. This type 

of information is needed by resource managers in defining 

the endpoint of their management actions. Information is 

presented on the functional role of these species in sustaining the biological and physical integrity of these habitats. 

INVASIVE SPECIES

297. Medine, A.J. 1981. Potential impacts of energy development upon water quality of Lake Powell and the Upper 

Colorado River. In: Adams, V.D.; Lamarra, V.A., eds. 

Aquatic resources management of the Colorado River 

ecosystem. Proceedings of the 1981 symposium on the 

aquatic resources management of the Colorado River 

ecosystem; 1981 November 16-18; Las Vegas, NV. Ann 

Arbor Science Publishers: 399-424.

Abstract: The objective of the study described in this paper 

was to examine the projected oil shale scenarios with respect 

to environmental concerns, particularly the impact of water 

quality in the upper Colorado River. WATER QUALITY

298. Meehan, W.R.; Swanson, F.J.; Sedell, J.R. 1977. Influences of riparian vegetation on aquatic ecosystems 

with particular reference to salmonid fishes and their 

food supply. In: Johnson, R.R.; Jones, D.A., tech. 

coords. Importance, preservation and management of 

riparian habitat: A symposium; 1977 July 9; Tucson, 

AZ. RP-RM-43. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 137-145.

Abstract: The riparian zone has important influences on the 

total stream ecosystem including the habitat of salmonids. 

Shade and organic detritus from the riparian zone control the 

food base of the stream, and large woody debris influences 

channel morphology. Temporal and spatial changes in the 

riparian zone, the indirect influences of riparian vegetation 

on salmonids, and the effects of man’s activities are discussed. 

MULTIPLE THREATS

299. Meents, J.K.; Anderson, B.W.; Ohmart, R.D. 1984. 

Sensitivity of riparian birds to habitat loss. In: Warner, 

R.E.; Hendrix, K.M., eds. California riparian systems: 

Ecology, conservation, and productive management. 

Berkeley: University of California Press: 619-625.

Abstract: The extent and composition of riparian plant communities in the lower Colorado River valley have historically 

been altered, primarily by man. Some of these communities 

are disappearing (cottonwood and mesquite), and others are 

expanding (saltcedar and arrowweed). We examined the avian 

community associated with riparian vegetation and identified avian habitat specialists. Nearly all of these specialists 

are concentrated in cottonwood/willow or honey mesquite 

communities. Saltcedar generally supported no avian species 

with narrow habitat breadth. INVASIVE SPECIES

300. Mehlhop, P.; Vaughn, C.C. 1993. Threats to and sustainability of ecosystems for freshwater mollusks. In: 

Covington, W.W.; DeBano, L.F., tech. coords. Sustainable ecological systems: Implementing an ecological 

approach to land management; 1993 July 12-15; Flagstaff, AZ. Gen. Tech. Rep. RM-247. Fort Collins, CO: 

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

Mountain Forest and Range Experiment Station: 68-77.

Abstract: This paper examines the ecological and life history 

characteristics of two groups of mollusks of North America—

prosobranch snails and riverine bivalves—that have suffered 

declines due to human activities or appear to be threatened 

with declines in the future. MULTIPLE THREATS

301. Merritt, D.M.; Poff, N.L. 2010. Shifting dominance of 

riparian Populus and Tamarix along gradients of flow 

alteration in western North American rivers. Ecological 

Applications. 20(1): 135-152.

Abstract: The study presented in this paper was a natural 

experiment in eight ecoregions in arid and semiarid portions 

of the western United States, measuring Tamarix and native 

Populus recruitment and abundance at 64 sites along 13 

perennial rivers spanning a range of altered flow regimes. 

Based on their results the authors infer that Tamarix would 

have naturalized, spread, and established widely in riparian 

communities in the absence of dam construction, diversion, 

and flow regulation in the western United States. However, 

Tamarix dominance over native species would likely be less 

extensive in the absence of human alteration of river-flow 

regimes. INVASIVE SPECIES
54 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

302. Minckley, W.L.; Brown, D.E. 1982. Southwest wetlands. 

Biotic communities in the American Southwest United 

States and Mexico. In: Brown, D.A., ed. Desert Plants. 

Vol. 4, No. 1-4, part 6. Tucson, AZ: University of Arizona Press: 223-288.

Abstract: Part 6 of this publication differentiates and/or shows 

maps of aquatic, riparian and other wetland biotic communities of the American Southwest. It classifies aquatic habitats, 

wetlands and riparian communities, gives a brief description 

of each, provides examples, and addresses threats and other 

management challenges. MULTIPLE THREATS

303. Mortenson S.G.; Weisberg, P.J.; Ralston, B.E. 2008. Do 

beavers promote the invasion of non-native Tamarix in 

the Grand Canyon riparian zone? Wetlands. 28: 666-675.

Abstract: A spatial analysis was conducted to assess whether 

the presence of beavers correlates with the relative of Salix

and Tamarix. Results showed that riparian surfaces covered 

by Tamarix was significantly greater for sites where beavers 

were present. This indicates that either Tamarix and beavers 

co-occur in similar habitats, beavers prefer habitats that have 

high Tamarix cover, or beavers contribute to Tamarix dominance through selective use of its native woody competitors. 

INVASIVE SPECIES

304. Mosley, J.C.; Cook, P.S.; Griffis, A.J.; O’Laughlin, J. 

1997. Guidelines for managing cattle grazing in riparian areas to protect water quality: Review of research 

and best management practices policy. Report No.15. 

Moscow, ID: University of Idaho: Idaho Forest, Wildlife, 

and Range Policy Analysis Group: 67p.

Abstract: This report attempts to reply to three focus questions about riparian grazing: what management strategies are 

indicated by research, how are BMPs administered, and how 

does state policy protect water quality? GRAZING

305. Mount, J.W.; Krausman, W.; Finch, D.M. 1996. Riparian habitat change along the Isleta-Belen reach of the 

Middle Rio Grande. In: Shaw, D.W.; Finch, D.M., tech. 

coords. Desired future conditions for southwestern 

riparian ecosystems: Bringing interests and concerns 

together. Gen. Tech. Rep. RM-272. Fort Collins, CO: 

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

Mountain Forest and Range Experiment Station: 48-68.

Abstract: This paper provides a summary of vegetation 

changes over an 11-year period (1984-1995) in the middle 

reach of the Rio Grande. Over this time span the bosque 

vegetation has aged, exotic woody species, saltcedar, and 

Russian olive have increased in cover. In some cases, introduced species have replaced other vegetation such as coyote 

willow. Thirty-one fire events, which altered vegetation, had 

also been recorded. MULTIPLE THREATS

306. Mueller, D.K.; Moody, C.D. 1984. Historical trends in 

concentration and load of major ion in the Colorado River 

System. In: French, R.H., ed. Salinity in watercourses 

and reservoirs: Proceedings of the 1983 international 

symposium on state-of-the-art control of salinity; 1984 

July 13-15, Salt Lake City UT. Boston MA: Butterworth 

Publishers: 181-192.

Abstract: During the early 1970s salinity in the lower Colorado River was recognized as a basin-wide problem. This paper 

reports on the method developed to generate mean monthly 

discharge and concentration values and present preliminary 

results of the trend analysis. WATER QUALITY

307. Mueller, G.; Marsh, P. 1995. Bonytail and razorback 

sucker in the Colorado River basin. In: LaRoe, E.T.; 

Farris, G.S.; Puckett, C.E.; Doran, P.D.; Mac, M.J., eds. 

Our living resources: A report to the nation on the distribution, abundance, and health of U.S. plants, animals, 

and ecosystems. Washington, DC: U.S. Department of 

the Interior, National Biological Service: 324-326

Abstract: The dramatic decline prompted the listing of the 

bonytail as endangered in 1980, and a similar listing for the 

razorback sucker followed in 1991. Although both fishes are 

Federally protected and recovery programs began over 15 

years ago, these species continue to edge toward extinction. 

The problem lies in the complexity of the environmental 

and legal issues, combined with possible conflicts in land, 

water, and fishery- management philosophies. MULTIPLE 

THREATS

308. Myers, L.H. 1989. Grazing and riparian management 

in southwestern Montana. In: Gresswell, R.E.; Barton, 

B.A.; Kershner, J.L., eds. Practical approaches to riparian resource management: An educational workshop; 

1989 May 8-11; Billings, MT. U.S. Department of the 

Interior, Bureau of Land Management: 117-120.

Abstract: A subjective analysis of riparian vegetation response 

in 34 grazing systems was completed. Common denominators 

to both poor and good riparian management are discussed 

and recommendations are provided. GRAZING

309. Naiman, R.J.; Décamps, H. 1997. The ecology of interfaces: Riparian zones. Annual Review of Ecology and 

Systematics. 28(1): 621-658.

Abstract: This article provides an overview of important 

characteristics of riparian zones, describes physical effects on 

adjacent environments, summarizes ecological characteristics, 

and discusses consequences of environmental alterations on 

ecosystem form and function. MULTIPLE THREATS

310. Naiman, R.J.; Turner, M.G. 2000. A future perspective 

on North America’s freshwater ecosystems. Ecological 

Applications. 10(4): 958-970.

Abstract: This article explores trends in alterations to freshwater ecosystems, discusses the ecological consequences of 

biophysical alterations expected to occur in the next 20–30 

years, and identifies some of the major scientific challenges 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 55

and opportunities to effectively address the changes. Topics 

discussed include altered hydrological regimes, biogeochemical cycles, altered land use, riparian management, life history 

strategies, and relations between climate change and water 

resource management. MULTIPLE THREATS

311. Naiman, R.J.; Bunn, S.E.; Nilsson, C.; Petts, G.E.; Pinay, 

G.; Thompson, L.C. 2002. Legitimizing fluvial ecosystems as users of water: An overview. Environmental 

Management. 30(4): 455-467.

Abstract: This article articulates some fundamental relationships between physical and ecological processes, presents basic principles for maintaining the vitality of fluvial 

ecosystems, identifies several major scientific challenges 

and opportunities for effective implementation of the basic 

ecological principles, and acts as an introduction to three 

specific articles to follow on biodiversity, biogeochemistry, 

and riparian communities. All the objectives, by necessity, 

link climate, land, and fresh water. Additionally, forecasting 

the ecological consequences of changing water regimes is a 

fundamental challenge for science, especially as environmental issues related to fresh waters escalate in the next two to 

three decades. CLIMATE CHANGE

312. National Academy of Science. 2002. Riparian areas: 

Functions and strategies for management. Washington, 

DC: National Academy Press. 428 p.

Abstract: This report by the National Academy of Science 

examines the structure and functioning of riparian ecosystems, 

how they have been altered by human activity, their legal 

status, and their potential for management and restoration. 

MULTIPLE THREATS

313. Neary, D.G.; Medina, A.L. 1996. Geomorphic response 

of a montane riparian habitat to interactions of ungulates, vegetation and hydrology. In: Shaw, D.W.; Finch, 

D.M., tech. coords. Desired future conditions for 

southwestern riparian ecosystems: Bringing interests 

and concerns together. Gen. Tech. Rep. RM-272. Fort 

Collins, CO: U.S. Department of Agriculture, Forest 

Service, Rocky Mountain Forest and Range Experiment 

Station: 143-147.

Abstract: Wildcat Creek, a tributary of the Black River on 

the Apache-Sitgreaves National Forest is being studied to 

determine the impacts of cattle and elk grazing on riparian 

wet meadows. Grazing and trampling impacts of elk and 

cattle were found to affect the aggradation/degradation process in a pool-riffle sequence in two ways: (1) overgrazing 

of stream banks resulted in exposure of the soil fabric and 

loss during high flows, sloughing banks, channel widening, 

and a reduction in the ability of plants to trap sediments; and 

(2) trampling at animal crossing initiated a degradation of 

riffles by breaking down the armoring gravels that are held 

in place by native aquatic plants. GRAZING

314. Nelson, S.M. 2003. The Western Viceroy butterfly (Nymphalidae: Limenitis archippus obsoleta): An indicator 

for riparian restoration in the arid southwestern United 

States? Ecological Indicators. 3: 203–211.

Abstract: The purpose of this study was to study the autecology of the Western Viceroy butterfly (Limenitis archippus 

obsoleta) against the background of riparian restoration. 

Studies took place on the Bill Williams River, which contains a naturally functioning cottonwood/willow ecosystem. 

INSECTS, MULTIPLE THREATS

315. Nilsson, C.; Berggren, K. 2000. Alterations of riparian 

ecosystems caused by river regulation. BioScience. 

50(9): 783-792.

Abstract: Hydrological alterations—to ensure water for 

agricultural, industrial, and domestic purposes, for hydroelectricity or for flood protection—have changed ecosystem 

structures and processes in running waters and associated 

environments the world over. In this article, the authors discuss 

the global-scale ecological changes in riparian ecosystems 

resulting from dam operations including examples in western 

North America. DAM CONSTRUCTION

316. Noll, W.; Williams, S.; Boyce, R. 1988. Grande Ronde 

River Basin: Fish habitat improvement implementation 

plan. Oregon Department of Fish and Wildlife; U.S. 

Department of Energy, Bonneville Power Administration: 39p.

Abstract: This plan identifies existing habitat problems, 

solutions, goals and objectives, priorities, estimated project 

costs and associated fishery benefits. The program provides 

for treatment of approximately 66 miles of stream habitat 

from 1988 to 1991. The primary factor limiting Chinook 

and steelhead production is rearing habitat including (1) high 

summer water temperatures, (2) low summer flows, (3) lack 

of riparian vegetation, (4) lack of habitat diversity, and (5) 

poor channel stability. MULTIPLE THREATS

317. Norcross, E.; Calvo, G. 1993. Private lands river protection: Balancing private and public concerns. In: Tellman, B.; Cortner, H.J.; Wallace, M.G.; DeBano, L.F.; 

Hamre, R.H., tech. coords. Riparian management: Common threads and shared interests. A western regional 

conference on river management strategies; 1993 Feb 

4-6; Albuquerque, NM. Gen. Tech. Rep. RM-226. Fort 

Collins, CO: U.S. Department of Agriculture, Forest 

Service, Rocky Mountain Forest and Range Experiment 

Station: 55-69.

Abstract: This paper describes the state of the nation’s rivers including the threats posed to riparian areas. Further, it 

explains some of the difficulties inherent in managing rivers 

on private lands, and provides a summary of existing and 

proposed private lands river protection tools. MULTIPLE 

THREATS
56 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

318. Oakley, A.L.; Collins, J.A.; Everson, L.B.; Heller, D.A.; 

Howerton, J.C.; Vincent, R.E. 1985. Riparian zones and 

freshwater wetlands. In: Brown, E.R., ed. Management 

of wildlife and fish habitats in forests of western Oregon 

and Washington, Part. 1. Portland, OR: U.S. Department of Agriculture Forest Service, Pacific Northwest 

Region: 57-80.

Abstract: Riparian zones and freshwater wetlands are among 

the most heavily used wildlife habitats occurring in forest 

lands of western Oregon and Washington. Biologists have 

recognized this for years but only recently has the significance 

of riparian and wetland productivity been well quantified by 

research studies. Of the references cited in this chapter, the 

majority have been published since 1970. Results of ongoing research are expected to further substantiate and expand 

our knowledge of wildlife use in these habitats. MULTIPLE 

THREATS

319. Obedzinski, R.A.; Shaw, C.G.; Neary, D.G. 2001. Declining woody vegetation in riparian ecosystems of the 

Western United States. Journal of Applied Forestry. 

16(4): 169-181.

Abstract: This article examines the decline of woody vegetation in keystone riparian ecosystems and clarifies what issues 

need to be addressed for successful and sustainable riparian 

restoration. It is an overview of the factors implicated in the 

decline of woody riparian vegetation and the interactions 

among these factors. Causes of decline discussed include: 

exotic species invasion, stress-induced mortality, increases 

in insect and disease attack, drought, beaver, fire, climate 

change, and anthropogenic activities, such as agricultural 

development, groundwater depletion, dam construction, 

water diversion, grazing, recreation, urbanization, timber 

harvesting, and mining. MULTIPLE THREATS

320. Ohmart, R.D. 1996. Ecological condition of the East 

Fork of the Gila River and selected tributaries: Gila 

National Forest, New Mexico. In: Shaw, D.W.; Finch, 

D.M., tech. coords. Desired future conditions for 

southwestern riparian ecosystems: Bringing interests 

and concerns together. Gen. Tech. Rep. RM-272. Fort 

Collins, CO: U.S. Department of Agriculture, Forest 

Service, Rocky Mountain Forest and Range Experiment 

Station: 312-317.

Abstract: Numerous anthropogenic factors have been involved in the degradation of Gila River riparian systems to 

their current condition, but the major degrading force has been 

unmanaged domestic livestock grazing either season-long or 

year-long. Potential to recover these fluvial systems or proper 

functioning condition is high with management intervention. 

Stream gradients are moderate to low and sediment loads 

sufficient for bank formation. MULTIPLE THREATS

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

livestock grazing on fish and wildlife resources in 

western riparian habitats. Krausman, P.R., ed. Rangeland 

wildlife. Denver, CO: Society of Rangeland Management: 245-279.

Abstract: There are many agents of riparian destruction and 

degradation other than overgrazing by domestic livestock. 

Most of these have been along major western streams, while 

unmanaged livestock degradation, the focus of this chapter, 

has been ubiquitous and at all elevations. GRAZING

322. Ohmart, R.D.; Anderson, B.W.; Hunter, W.C. 1985. Influence on waterbird, wader, and shorebird use along the 

lower Colorado River. In: Johnson, R.R.; Ziebell, C.D.; 

Patton, D.R.; Ffolliott, P.F.; Hamre, R.H., tech. coords. 

Riparian ecosystems and their management: reconciling conflicting uses. First North American riparian 

conference; 1985 April 16-18; Tucson, AZ. Gen. Tech. 

Rep. RM-120. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 117-122.

Abstract: Waterbird, wader, and shorebird use of the Colorado 

River was restricted to habitats in or immediately adjacent 

to the river prior to agriculture development. The authors 

studied agricultural habitats systematically for three years 

and identified those agricultural settings that were most 

important for individual species and groups of waterbirds, 

waders, and shorebirds. AGRICULTURE

323. Ohmart, R.D.; Deason, W.O.; Burke, C. 1977. A riparian 

case history: The Colorado River. In: Johnson, R.R.; 

Jones, D.A., tech. coords. Importance, preservation and 

management of riparian habitat: A symposium; 1977 

July 9; Tucson, AZ. Res. Pap. RM-43. Fort Collins, CO: 

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

Mountain Forest and Range Experiment Station: 35-47.

Abstract: Historically to present, cottonwood communities 

have declined in abundance along the lower Colorado River 

to the condition that the future of this natural resource is 

precarious. Avian species showing strong specialization to 

cottonwood communities may be extirpated should the cottonwood community be lost from the river. Only through the 

concern and action by responsible agencies can we assure the 

persistence of this natural resource. MULTIPLE THREATS

324. Olson, R.W.; Armour, C.L. 1978. Economic considerations for imposed livestock management approaches 

for fish and wildlife in riparian/stream areas. In: Cope, 

O.B., ed. Proceedings of the forum—grazing and riparian/stream ecosystems. 1978 Nov. 3-4; Denver, CO. 

Arlington, VA: Trout Unlimited: 67-71.

Abstract: In this paper complex interrelationships between 

various range uses are conceptualized. A perspective is presented about monetary values of rangeland use of ranchers, 

consumers, and hunters. Additionally, economic ramifications 

of implementation of improved riparian management techniques on fish and wildlife resources are addressed. GRAZING
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 57

325. Olson, T.E.; Gray, M.V. 1988. Characteristics of least 

Bell’s vireo nest sites along the Santa Ynez River. In: 

Abell, D.L., coord. Proceedings of the California riparian systems conference: Protection, management, 

and restoration for the 1990’s; 1988 September 22-24; 

Davis, CA. Gen. Tech. Rep. PSW-110. Berkeley, CA: 

U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station: 

278-284.

Abstract: Due primarily to alteration of riparian vegetation 

and nest parasitism by brown cowbirds, the least Bell’s vireo 

has undergone a tremendous decline in range and numbers 

since the 1920s. The objective of this study was to characterize nest sites of least Bell’s vireos and to describe trends in 

use of nesting habitat within the Santa Ynez River drainage. 

INVASIVE SPECIES

326. Olson, T.E; Knopf, F.L. 1986a. Agency subsidization of 

a rapidly spreading exotic. Wildlife Society Bulletin. 

14:492-493.

Abstract: Establishment of Russian-olive in North America 

has been promoted by State and Federal agencies using 

the species in plantings and providing seedlings to private 

landowners at less-than-market value. Because seedlings 

continue to be made available from these agencies, the rate 

of naturalization will surely continue to increase in western 

states and possibly in some areas of Canada and Mexico. 

INVASIVE SPECIES

327. Olson, T.E.; Knopf, F.L. 1986b. Naturalization of Russianolive in the western United States. Western Journal of 

Applied Forestry. 1: 65-69.

Abstract: Since its introduction into the United States, 

Russian-olive has escaped cultivation at many locations. This 

exotic tree is now present in every western State, especially 

within riparian zones. The species has high value for wildlife, 

but can interfere with agricultural practices and has potential 

to displace native riparian trees. INVASIVE SPECIES

328. Omernik, J.M.; Abernathy, A.R.; Male, L.M. 1981. Relationships between surface water nutrient levels and 

proximity of agricultural and forest land to receiving 

waters. In: Stefan, H.G., ed. Proceedings of the symposium on surface water impoundments (Vol. 1); 1981 June 

2-5; Minneapolis, MN. New York: American Society 

of Civil Engineers: 323-334.

Abstract: The primary objective of this study was to clarify 

the buffer strip/surface water nutrient level relationship by 

determining whether or not consideration of proximity of two 

land use types (agriculture and forest) to streams improved 

the ability to predict stream nutrient levels over simply using the proportion of watershed occupied by each land use. 

WATER QUALITY

329. Parmenter, R.R. 2009. Applying hydrology to land 

management on the Valles Caldera National Preserve. 

Southwest Hydrology. 8(2): 22-23.

Abstract: This paper provides a brief summary of the management history, challenges, and future plans that will affect 

the hydrology and riparian ecosystems within this National 

Preserve. MULTIPLE THREATS

330. Petrosky, C.E.; Holubetz, T.B. 1985. Idaho habitat evaluation for offsite mitigation record: Annual report FY 

1984. Report to U.S. Department of Energy, Bonneville 

Power Administration, Contract No. 1984BP13381, 

Project No. 198300700. Boise: Idaho Department of 

Fish and Game.

Abstract: Man’s activities in Idaho, namely logging, intensive 

livestock grazing, mining and agriculture, have degraded 

many streams. The purpose of this study is to (1) document 

physical changes in habitat, (2) measure changes in steelhead 

and Chinook production attributable to habitat enhancement 

projects, (3) measure changes in standing crops of resident 

fish species due to enhancement, and (4) determine project 

effectiveness. MULTIPLE THREATS

331. Pettit, N.E.; Naiman, R.J. 2007. Fire in the riparian 

zone: Characteristics and ecological consequences. 

Ecosystems. 10: 673-687.

Abstract: The authors review the current understandings of the 

frequency, spatial distributions, mechanisms, and ecological 

consequences of fire in riparian zones. They conclude that 

riparian fires are potentially important in shaping ecological 

characteristics in many regions, but that this is poorly quantified and that a better understanding is essential to access 

the effects of fire in helping shape the complex ecological 

characteristics of the riparian zones over the longer-term. FIRE

332. Pinay, G.; Clément, J.C.; Naiman, R.J. 2002. Basic 

principals and ecological consequences of changing 

water regimes on nitrogen cycling in fluvial systems. 

Environmental Management. 30(4): 481-491.

Abstract: This article addresses three basic ecological principles driving the biogeochemical cycle of nitrogen in river 

systems: (1) how the mode of nitrogen delivery affects river 

ecosystem functioning, (2) how increasing contact between 

water and soil or sediment increases nitrogen retention and 

processing, and (3) the role of floods and droughts as important natural events that strongly influence pathways of 

nitrogen cycling in fluvial systems. New challenges related 

to the cumulative impact of water regime change, the scale 

of appraisal of these impacts, and the determination of the 

impacts due to natural and human changes are discussed. It 

is suggested that cost of long-term and long-distance cumulative impacts of hydrological changes should be evaluated 

against short-term economic benefits to determine the real 

environmental costs. MULTIPLE THREATS
58 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

333. Pister E.P.; Kerbavaz, J.H. 1984. Fish Slough: A case 

study in management of a desert wetland system. In: 

Warner, R.E.; Hendrix, K.M., eds. California riparian 

systems: Ecology, conservation, and productive management. Berkeley: University of California Press: 929-933.

Abstract: Fish Slough is a remnant of a once widespread, 

shallow aquatic/riparian wetland in the arid Owens Valley. 

Fish Slough supports a variety of rare species, including the 

endangered Owens pupfish. Water exports and introduction 

of exotic fish species has led to the near extinction of this 

endangered species. Successes and failures of management 

efforts at Fish Slough hold lessons for management of other 

endangered species and natural areas. MULTIPLE THREATS

334. Platts, W.S. 1974. Geomorphic and aquatic conditions 

influencing salmonids and stream classification. U.S. 

Department of Agriculture, Forest Service, Surface 

Environment and Mining Program: 199 p.

Abstract: Investigations were conducted of (1) the physical 

structure of aquatic environments in grantic, mountainous 

lands in Idaho, (2) the relationship between the physical 

stream structure and fish populations, (3) the influence of 

geomorphic process of aquatic ecosystems, (4) the relation of order within landforms in relation to uniformity in 

aquatic environments, and (5) the potential for classifying 

aquatic environments from land classification systems. A 397 

square mile area in the upper south fork of the Salmon River 

watershed was stratified into four geologic process groups 

and 12 geomorphic types. Within that area, 38 streams were 

studied by analyzing 2,482 transects for physical aquatic and 

streambank environments, while 291 areas were investigated 

as to fish populations. MULTIPLE THREATS

335. Platts, W.S. 1978. Livestock grazing and riparian/

stream ecosystems—an overview. In: Cope, O.B., ed. 

Proceedings of the forum—grazing and riparian/stream 

ecosystems; 1978 Nov. 3-4; Denver, CO. Arlington, VA: 

Trout Unlimited: 39-45.

Abstract: Streams have been subjected to damaging events 

since the day they were formed, initially by such natural 

events as glaciation, floods, climatic temperature changes and 

droughts, and, more recently, by man colonizing along stream 

banks and using the stream and its surroundings for mining, 

lumbering, livestock grazing, road construction, and sewage 

and waste disposal. This paper points out that (1) solutions to 

grazing problems are not easily found; (2) no single discipline 

possesses the skills and knowledge for all problem-solving; 

(3) past studies have identified many problems and offered 

some guidance; (4) more studies are needed to develop better 

understanding; (5) agencies responsible for the management 

of the streamside environment have not adequately considered 

the influence of livestock grazing; and (6) not all answers 

will be found in the near future. GRAZING

336. Platts, W.S. 1984. Riparian system/livestock grazing 

interaction research in the Intermountain West. In: 

Warner, R.E.; Hendrix, K.M., eds. California riparian 

systems: Ecology, conservation, and productive management. Berkeley: University of California Press: 424-429.

Abstract: This paper presented research that identifies the 

influences livestock grazing has on riparian and aquatic 

ecosystems. A research study was initiated in 1975 by the 

USDA Forest Service that studied grazing influences and 

developed solutions so managers would have the best information to evaluate range management alternatives. Preliminary 

findings on continuous and rest-rotation grazing systems are 

discussed. GRAZING

337. Platts, W.S. 1989. Compatibility of livestock grazing 

strategies with fisheries. In: Gresswell, R.E.; Barton, 

B.A.; Kershner, J.L., eds. Practical approaches to riparian resource management: An educational workshop; 

1989 May 8-11; Billings, MT. U.S. Department of the 

Interior, Bureau of Land Management: 103-110.

Abstract: A better understanding of management strategies 

with respect to their stream-riparian compatibility should 

help fishery specialists work more closely and effectively 

with range conservationists in rangeland management. These 

strategies are discussed here. GRAZING

338. Platts, W.S.; Nelson, R.L. 1989. Characteristics of riparian plant communities and streambanks with respect 

to grazing in northeastern Utah. In: Gresswell, R.E.; 

Barton, B.A.; Kershner, J.L., eds. Practical approaches 

to riparian resource management: An educational workshop; 1989 May 8-11; Billings, MT. U.S. Department 

of the Interior, Bureau of Land Management: 73-81.

Abstract: Streambanks and associated riparian vegetation 

were studied in grazed and ungrazed pastures along Big 

Creek, Utah, to determine whether differences in streamside 

community type composition and condition were related to 

differences in streambank morphology. Considerable structural difference was observed between grazed sites and sites 

where grazing has been suspended or greatly reduced for 

nearly 2 years. GRAZING

339. Platts, W.S.; Gebhardt, K.A.; Jackson, W.L. 1985. The 

effects of large storm events on basin-range riparian stream habitats. In: Johnson, R.R.; Ziebell, C.D.; 

Patton, D.R.; Ffolliott, P.F.; Hamre, R.H., tech. coords. 

Riparian ecosystems and their management: Reconciling conflicting uses. First North American riparian 

conference; 1985 April 16-18; Tucson, AZ. Gen. Tech. 

Rep. RM-120. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 30-34.

Abstract: Large storm events had major impacts on stream 

riparian reaches that had received heavy livestock grazing. 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 59

One ungrazed rehabilitated stream reach actually improved 

in habitat condition while two adjacent grazed stream reaches 

decreased. Each stream reacted differently to channel erosion, 

with two streams showing mainly lateral channel movement 

and the third stream exhibiting vertical channel movement. 

GRAZING

340. Poff, B.; Tecle, A. 2002. Bacteriological water quality 

trend analysis in Oak Creek Canyon, Arizona. In: Proceedings: Ground water/surface water interactions. 2002 

summer specialty conference; 2002 July 1-3. Keystone, 

CO: American Water Resources Association: 431-436.

Abstract: This paper analyzes the temporal and spatial distribution of bacterial contamination at Slide Rock Park in Oak 

Creek Canyon, Arizona. Sources of contamination include 

livestock and wildlife grazing in the forests above the creek, 

domesticated and wild animals, residential homes inside the 

canyon and the recreationist visiting the canyon. The data 

shows some correlation between the numbers of visitors and 

E. coli counts at the Slide Rock State Park. WATER QUALITY

341. Poff, N.L.; Zimmerman, J.K.H. 2010. Ecological responses to altered flow regimes: A literature review to 

inform the science and management of environmental 

flows. Freshwater Biology. 55: 194-205.

Abstract: For this literature review 165 papers published over 

the last four decades were assessed, with a focus on more recent 

papers. This analysis does not support the use of the existing 

global literature to develop general, transferable quantitative 

relationships between flow alteration and ecological response. 

However, they do support the inference that flow alteration 

is associated with ecological change and that the risk of 

ecological change increases with increasing magnitude of 

flow alteration. CLIMATE CHANGE, FLOW REGULATION

342. Poff, N.L.; Olden, J.D.; Merritt, D.M.; Pepin, D.M. 2007. 

Homogenization of regional river dynamics by dams 

and global biodiversity implications. Proceedings of the 

National Academy of Science. 104: 5732-5737.

Abstract: The authors used 186 long-term streamflow 

records on intermediate-sized rivers across the continental 

United States to show that dams have homogenized the flow 

regimes on third- through seventh-order rivers in 16 historically distinctive hydrologic regions over the course of the 

20th century. Such quantitative analysis provides the basis for 

conservation and management actions aimed at restoring and 

maintaining native biodiversity and ecosystem function and 

resilience for regionally distinct ecosystems at continental 

to global scales. DAM CONSTRUCTION

343. Potyondy, J.P. 1992. Technical issues related to nonpoint source management. In: Neary, D.G.; Ross, K.C.; 

Coleman, S., eds. Proceedings of the national hydrology 

workshop; 1992 April 27- May 1; Phoenix, AZ. Gen. 

Tech. Rep. RM-279. Fort Collins, CO: U.S. Department 

of Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 65-73.

Abstract: Non-point source control strategies rely primarily 

on the application of Best Management Practices (BMPs) 

as the means to achieve protection of designated beneficial 

uses. The continued use of BMPs appears to offer important 

advantages over instream water quality standards and their 

continued use is suggested. In the long-term, monitoring data 

accumulated to evaluate BMPs can be used to build a sound 

scientific basis for eventual evolution to water quality based 

approaches. WATER QUALITY

344. Prange, R. 1993. Duck Creek riparian habitat restoration 

project. In: Tellman, B.; Cortner, H.J.; Wallace, M.G.; 

DeBano, L.F.; Hamre, R.H., tech. coords. Riparian 

management: Common threads and shared interests. 

A western regional conference on river management 

strategies; 1993 Feb 4-6; Albuquerque, NM. Gen. Tech. 

Rep. RM-226. Fort Collins, CO: U.S. Department of 

Agriculture Forest Service, Rocky Mountain Forest and 

Range Experiment Station: 395-396.

Abstract: This paper describes the successful restoration of 

the Duck Creek riparian habitat, through fencing to protect 

streambanks from livestock grazing. GRAZING

345. Pringle, C.M. 2000. Threats to U.S. public lands from 

cumulative hydrologic alterations outside of the their 

boundaries. Ecological Applications. 10(4): 971-989.

Abstract: This paper is based on synthesis and summary of 

existing information and emerging trends. It highlights immediate problems facing managers of freshwater resources 

on public lands and is not meant to be a comprehensive 

treatise. Major goals are to (1) describe regional differences 

in the availability of fresh water, rates of human population 

growth, and the distribution of public lands in the United 

States; (2) summarize the general extent and magnitude of 

current pressures on water resources in those categories of 

public lands where there is a strong emphasis on managing 

aquatic ecosystems for environmental needs (i.e., national 

parks, national forests, and national wildlife refuges); and 

(3) discuss two case studies where science-management 

linkages have been effective in implementing some localized 

solutions, yet where many landscape-scale problems remain 

to be addressed. This analysis is intended to place the water 

resources issues faced by public lands into a broader context 

and to illustrate the increasing need to understand the cumulative and long-term ecological effects of hydrologic alterations 

outside of public land boundaries. MULTIPLE THREATS

346. Queheillalt, D.M.; Morrison, M.L. 2006. Vertebrate use 

of a restored riparian site: A case study on the central 

coast of California. Journal of Wildlife Management. 

70(3): 859-866.

Abstract: The primary objective of the study described in 

this research note was to determine use by vertebrates of 
60 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

a riparian restoration site (Carmel-by-the-Sea, California, 

U.S.A.). The study can be used as an example of how the effectiveness of an ongoing restoration project can be assessed 

and modified. MULTIPLE THREATS

347. Radtke, D.B. 1990. Environmental contaminants in the 

lower Colorado River Valley, Arizona, California and 

Nevada. In: Proceedings of the Arizona Hydrological 

Society’s second annual symposium; Water quality and 

quantity issue into the 1990s: Adaptation to current 

realities; 1990 September 14-16; Casa Grande, AZ. 

Arizona Hydrological Society: 21 p.

Abstract: This paper presents the results of a reconnaissance 

irrigation drainage study in the lower Colorado River Valley, 

Arizona, California, and Nevada. Water, bottom sediment, 

and biota were sampled and analyzed for selected inorganic 

and synthetic organic constituents that may be present at toxic 

concentrations. Selenium was the only inorganic constituent 

that exceeded any existing standard, criterion or guideline for 

protection of wildlife resources. WATER QUALITY

348. Rashin, E.B.; Clishe, C.J.; Loch, A.T.; Bell, J.M. 2006. 

Effectiveness of timber harvest practices for controlling 

sediment related water quality impacts. Journal of the 

American Water Resources Association. 42(5): 1307-1327.

Abstract: Timber harvest best management practices (BMPs) 

in Washington State were evaluated to determine their effectiveness at achieving water quality standards pertaining to 

sediment related effects. Practices for ground-based harvest 

and cable yarding in the vicinity of small streams without 

buffers were ineffective or only partially effective at preventing water quality impacts. Recommendations are given for 

practices that provide a high confidence of achieving water 

quality standards by preventing chronic sediment delivery and 

avoiding direct channel disturbance. FOREST HARVESTING

349. Ray, D.; Woodroof, W.; Roberts, R.C. 1984. Management of riparian vegetation in the North Coast region 

of California’s Coastal Zone. In: Warner, R.E.; Hendrix, K.M., eds. California riparian systems: Ecology, 

conservation, and productive management. Berkeley: 

University of California Press: 660-672.

Abstract: Riparian vegetation has important habitat and 

economic values. The Coastal Act requires protection of both 

of these sets of values. Local coastal plans have attempted to 

resolve this policy conflict by protecting riparian corridors 

and habitat patches. Protection of large areas of riparian 

vegetation by land-use regulation has proven difficult. MULTIPLE THREATS

350. Reeder, R., ed. 1994. Riparian road guide: Managing 

roads to enhance riparian areas. Washington, DC: Terrene Institute. 32 p.

Abstract: This short booklet provides a description of how 

anthropogenic activities, (road construction in particular) 

has negatively impacted riparian systems in the semi-arid 

Southwest. It also provides examples of successful measures 

to avoid these negative impacts. ROADS

351. Reichard, N. 1988. Restoring and maintaining riparian 

habitat on private pastureland. In: Abell, D.L., coord. 

Proceedings of the California riparian systems conference: Protection, management, and restoration for the 

1990’s; 1988 September 22-24; Davis, CA. Gen. Tech. 

Rep. PSW-110. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and 

Range Experiment Station: 211-216.

Abstract: Protecting riparian habitat from livestock grazing 

on private land is a complex task that requires paying attention to sociological and economic as well as physical and 

biological factors. Six livestock exclusion fencing projects 

on private property in northwestern California are described. 

The importance of long term maintenance and the need for 

landowner incentives are discussed. Significant gains may 

be made via a statewide, coordinated effort to encourage 

the protection of riparian habitat on private land. GRAZING

352. Reid. L.M. 2010. Cumulative effects of fuel treatments 

on channel erosion and mass wasting. In: Elliot, W.J.; 

Miller, I.S.; Audin, L., eds. Cumulative watershed effects of fuel management in the western United States. 

Gen. Tech. Rep. RMRS-GTR-231. Fort Collins, CO: 

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

Mountain Research Station: 101-125.

Abstract: This chapter describes characteristics of channel 

erosion and mass-wasting processes, the environmental factors 

that most strongly influence erosion processes, the mechanisms by which fuel treatments can influence those controlling factors, outlines strategies for determining whether such 

influences will occur, and describes how erosion evaluations 

might be incorporated into a cumulative impact analysis. The 

erosion processes discussed here include channel-bank erosion, gullying, soil creep, landsliding and related processes. 

FOREST HARVESTING

353. Richards, C.; Cernera, P.J. 1987. Salmon River habitat 

enhancement: Annual report FY 1986. Project no. 

83-359. U.S. Department of Energy, Bonneville Power 

Administration, Division of Fish and Wildlife.

Abstract: This study evaluates the effects of habitat enhancement on the habitat and fish community in various reaches of 

the Salmon River in Idaho, where increased sedimentation 

caused by mining activities had caused degradation of the 

aquatic habitat. In particular, the Bear Valley Creek (Middle 

Fork Salmon River), Yankee Fork Salmon River, and East 

Fork Salmon River/Herd Creek were evaluated. MINING

354. Richter, H.E. 2006. Participatory learning on the San 

Pedro: Designing the crystal ball together. Southwest 

Hydrology. 6: 24-25.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 61

Abstract: The contribution of groundwater from the regional 

aquifer to both the alluvial aquifer and baseflows in the river 

is essential to sustain the lush habitats of the San Pedro River 

in southeastern Arizona. However, increasing human water 

demands, in combination with drought, have the potential to 

alter the hydrologic context that sustains this riparian vegetation and impacts those species dependent on it. DROUGHT

355. Rieger, J.P.; Kreager, D.A. 1988. Giant Reed: A climax 

community of the riparian zone. In: Abell, D.L., coord. 

Proceedings of the California riparian systems conference: Protection, management, and restoration for the 

1990’s; 1988 September 22-24; Davis, CA. Gen. Tech. 

Rep. PSW-110. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and 

Range Experiment Station: 222-225.

Abstract: Active management of coastal streams is needed 

to ensure the continued existence of significant riparian 

systems in Southern California. The concept of a dynamic 

self-replacing plant community is no longer a truism there. In 

the past decade, one exotic species in particular, Giant Reed, 

has had an ever-increasing negative role in the succession of 

riparian systems. The aggressiveness of this exotic has enabled it to invade disturbed areas along many watercourses 

in Southern California. INVASIVE SPECIES

356. Rieman, B. 2003. Status of native fishes in the western 

United States and issues for fire and fuels management. 

Forest Ecology and Management. 178: 197-211.

Abstract: This paper suggests that progress toward more integrated management of forests and native fishes will require 

at least three steps: (1) better integration and development 

of a common conceptual foundation and ecological goals, 

(2) attention to landscape and ecological context, and (3) 

recognition of uncertainty. FIRE, FOREST HARVESTING

357. Rink, L.P.; Windell, J.R. 1988. Riparian wetland enhancement in the San Miguel River Valley, Telluride, CO. 

In: Mutz, K.M.; Cooper, D.J; Scott, M.L.; Miller, L.K. 

tech., coords. Restoration, creation and management 

of wetland and riparian ecosystems in the American 

West: Proceedings of a symposium; 1988 November 

14-16; Denver, CO. Boulder, CO: Society of Wetland 

Scientists, Rocky Mountain Chapter: 102-108.

Abstract: This paper describes a wetland mitigation project 

that was implemented concurrent with a development project and involved approximately 3 acres of riparian wetland 

enhancement. MULTIPLE THREATS

358. Rinne, J.N. 1985. Livestock grazing effects on southwestern streams: A complex research problem. In: 

Johnson, R.R.; Ziebell, C.D.; Patton, D.R.; Ffolliott, 

P.F.; Hamre, R.H., tech. coords. Riparian ecosystems 

and their management: Reconciling conflicting uses. 

First North American riparian conference; 1985 April 

16-18; Tucson, AZ. Gen. Tech. Rep. RM-120. Fort 

Collins, CO: U.S. Department of Agriculture, Forest 

Service, Rocky Mountain Forest and Range Experiment 

Station: 295-299

Abstract: Conducting viable research on the effects of domestic livestock grazing on stream environments and biota in 

southwestern National Forests is problematic. The multipleuse concept, spatio-temporal factors, inadequate control 

and replication, and changes in land management objectives 

and direction render it difficult to effectively study grazing 

impacts. GRAZING

359. Rinne, J.N. 1990. Minimizing livestock grazing effects 

on riparian stream habitats: Recommendations for research and management. In: Proceedings of a national 

conference on enhancing the states’ lake and wetland 

management programs; 1989 May 18-19; Chicago, IL. 

Northeastern Illinois Planning Commission: 15-28.

Abstract: Over 70 percent of historic riparian habitats in 

the United States have been lost through various land use 

practices, including grazing. Although grazing on public 

lands has been regulated for 50 years, this land use practice 

continues to have detrimental effects on riparian systems 

in the arid American Southwest. To date, much research on 

grazing effects on riparian systems has been deficient in 

design and brief in duration. GRAZING

360. Rinne, J.N. 1990. The utility of stream habitat and biota 

for identifying potential conflicting forest land uses: 

Montane riparian areas. Forest Ecology and Management. 33/34: 363-383.

Abstract: This paper reviews the literature on the use of fine 

sediment, aquatic macroinvertebrates, and fishes as indicators 

for identifying and describing the effects of various land-use 

practices on riparian-stream systems. Also, it presents the 

results of research on the effects of land-management activities on these three variables for several southwestern United 

States montane streams. MULTIPLE THREATS

361. Rinne, J.N. 1993. Declining southwestern aquatic habitats 

and fishes: Are they sustainable? In: Covington, W.W.; 

DeBano, L.F., tech. coords. Sustainable ecological 

systems: Implementing an ecological approach to land 

management; 1993 July 12-15; Flagstaff, AZ. Gen. Tech. 

Rep. RM-247. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 256-265.

Abstract: Rinne (1) discusses and summarizes the nature of 

the decline of aquatic resources in the region, (2) suggests 

necessary actions to halt and perhaps reverse this decline, and 

(3) attempts to answer the question: Are aquatic habitats and 

fishes sustainable in the American Southwest? MULTIPLE 

THREATS
62 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

362. Rinne, J.N. 2000. Fish and grazing relationships in 

southwestern national forests. In: Jemison, R.; Raish, C., 

eds. Livestock management in the American Southwest: 

Ecology, society, and economics. New York: Elsevier 

Science: 329-371

Abstract: This paper discusses the state of knowledge of relationships between fish, fish habitat, and grazing throughout 

the West and examines these relationships more specifically 

in Arizona and New Mexico. In the arid Southwest, riparian 

and instream areas frequently serve as fish habitat and are 

critical to the survival of threatened and endangered native 

fish species. Riparian and instream areas are also where 

domestic animals congregate to graze, which can have a 

considerable impact on riparian vegetation, which impacts 

fish habitat and populations. GRAZING

363. Risser, P.G. 1991. Impacts on ecosystems on global environmental changes in Pacific Northwest Watersheds. 

In: Naiman, R.J., ed. Watershed management: Balancing sustainability and environmental change. Seattle, 

WA: University of Washington, Center for Streamside 

Studies: 12-24.

Abstract: Climate change is producing subtle but measurable changes in ecosystem processes that are best measured 

at watershed scales. This paper examines ecosystem process 

change in a number of Pacific Northwest watersheds with 

long-term climate and watershed input-output data sets. Alterations in weather patterns due to global climatic processes, 

such as El Nino and La Nina, are creating significantly drier 

or wetter conditions and resultant decreases and increases in 

water flow. CLIMATE CHANGE

364. Roath, L.R.; Krueger, W.C. 1982. Cattle grazing influence on a mountain riparian zone. Journal of Range 

Management. 35: 100-103.

Abstract: A combination of management and physical 

topographic constraints caused cattle to concentrate on the 

riparian zone early in the grazing season in 1977 and 1978. A 

large percentage of cattle days and vegetation utilization on 

the riparian zone occurred in the first 4 weeks of the grazing 

period. Utilization on herbaceous vegetation was 76 and 72% 

in 1977 and 1978, respectively. Impact of grazing on the most 

prevalent species, Kentucky bluegrass, was minimal. Shrub 

use increased with increased maturity of herbaceous vegetation. Utilization of major shrubs was not excessive in either 

year, and very likely had no long-term effects on either the 

abundance or vigor of the shrubs. The interactions between 

herbaceous vegetation maturity and availability with shrub 

utilization are discussed. The measurements of vegetation use 

combined with observations were used to develop a qualitative 

assessment of livestock influences. GRAZING

365. Roath, R. 1986. Livestock management on riparian areas. In: Smits, J.H., ed. Management of riparian areas. 

Washington, DC: Public Lands Council: 41-43.

Abstract: Livestock influences on riparian areas can be 

regulated by management. However, for managers to regulate 

the impacts on riparian areas, a thorough understanding of 

the vegetation, livestock, and the interactions between both 

is required. GRAZING

366. Roberts, T.C., Jr. 1991. Political and social aspects of 

riparian area management. In: Clary, W.P.; McArthur, 

E.D.; Bedunah, D.; Wambolt, C.L., comps. Proceedings of the symposium on ecology and management 

of riparian shrub communities; 1991 May 29-31; Sun 

Valley, ID. Gen. Tech. Rep. INT-309. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Intermountain Research Station: 120-122.

Abstract: The author discusses three reasons why progress 

on riparian areas have been slow and suggests means for 

improvement. MULTIPLE THREATS

367. Roelle, J.E.; Hagenbuck, W.W. 1995. Surface cover 

changes in the Rio Grande floodplain, 1935-1989. In: 

LaRoe, E.T.; Farris, G.S.; Puckett, C.E.; Doran, P.D.; 

Mac, M.J., eds. Our living resources: A report to the 

nation on the distribution, abundance, and health of 

U.S. plants, animals, and ecosystems. Washington, DC: 

U.S. Department of the Interior, National Biological 

Service: 290-292.

Abstract: Agricultural conversion, urban and suburban 

expansion, water development, recreation, and invasion by 

non-native species such as Russian olive and saltcedar have 

severely reduced the extent and quality of riparian vegetation 

communities particularly in the arid and semi-arid Southwest. 

This article documents changes between 1935 and 1989 in 

cover types of the floodplain of the Rio Grande in central 

New Mexico. MULTIPLE THREATS

368. Rogers, T.J. 1996. Insects of the riparian. In: Shaw, D.W.; 

Finch, D.M., tech. coords. Desired future conditions for 

southwestern riparian ecosystems: Bringing interests 

and concerns together. Gen. Tech. Rep. RM-272. Fort 

Collins, CO: U.S. Department of Agriculture, Forest 

Service, Rocky Mountain Forest and Range Experiment 

Station: 154-156.

Abstract: This paper describes life histories, defoliation 

problems and other activities of insects associated with forest tree species growing along high elevation streams and 

riverbanks. In addition, examples of insects and diseases 

associated with lower elevations riparian areas are given. 

INSECTS, DISEASE

369. Rood, S.B.; Mahoney, J.M. 1990. Collapse of riparian poplar forests downstream from dams in western 

prairies: Probable causes and prospects for mitigation. 

Environmental Management. 14(4): 451-464.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 63

Abstract: This paper reviews reports of popular decline 

downstream from dams to determine and suggest mitigation 

and revegetation strategies. DAM CONSTRUCTION

370. Rood, S.B.; Mahoney, J.M.; Reid, D.E.; Zilm, L. 1995. 

Instream flows and the decline of riparian cottonwoods 

along the St. Mary River, Alberta. Canadian Journal of 

Botany. 73: 1250-1260.

Abstract: The St. Mary Dam enables water storage and diversion for irrigation. Consequently, river flows downstream 

are dramatically reduced during summer months. To assess 

historical changes in the abundance of riparian cottonwoods 

(Populus balsamifera, Populus angustifolia, and Populus 

deltoides), airphoto analyses were conducted for 40-km 

river reaches upstream and downstream from the dam and 

along adjacent dammed and undammed rivers. Cottonwoods 

along the lower St. Mary River are confined by steep-walled 

canyons to narrow bands. Analyses of the lineal river distance associated with cottonwoods revealed a 68% decline 

from 1951 to 1985. The decline was progressive during the 

period. Analyses of historical stream flows indicated that 

the cottonwood mortality was drought induced as a result of 

insufficient flows during the hot, dry summer periods and 

abrupt flow reductions following the high-flow period in 

the late spring. The riparian water table was determined to 

be closely coordinated with river stage, as changes in river 

elevation were followed by quantitatively similar changes in 

water table depth. Along the St. Mary River, reduced sedimentation downstream from the dam was not considered to be 

responsible for the cottonwood decline. The historically sparse 

cottonwood abundance along the lower St. Mary River may 

have reflected environmental conditions that were naturally 

only marginally suitable, and those groves may have been 

particularly vulnerable to the impacts of river flow regulation. 

DAM CONSTRUCTION, CLIMATE CHANGE

371. Rood, S.B.; Samuelson, G.M.; Weber, J.K.; Wywrot, 

K.A. 2005. Twentieth-century decline in streamflows 

from the hydrographic apex of North America. Journal 

of Hydrology. 306: 215-233.

Abstract: This study analyzed historic patterns of streamflow from the North American hydrographic apex with rivers 

selected (1) to represent headwaters that flow into the three 

oceans, (2) from watersheds with minimal human impacts, 

(3) from relatively free-flowing reaches upstream from major 

dams or diversion, and (4) with statistically sufficient hydrologic records. CLIMATE CHANGE

372. Rood, S.B.; Goater, L.A.; Mahoney, J.M.; Pearce, C.M.; 

Smith, D.G. 2007. Floods, fire and ice: Disturbance 

ecology of riparian cottonwoods. Canadian Journal of 

Botany. 85: 1019-1032.

Abstract: This literature review presents an assessment of 

the influences of three prominent physical disturbances, 

floods, fire, and ice on cottonwood population ecology along 

rivers from the central Rocky Mountain zone around the 

Canada–U.S. border. The authors conclude that (1) riparian 

cottonwoods are tolerant of and dependent on occasional 

physical disturbance for population rejuvenation; (2) differing disturbance responses contribute to niche differentiation across the Populus species; (3) different disturbances 

enable varied spatial and temporal patterns of cottonwood 

establishment; and (4) natural disturbance regimes favor native cottonwoods and disfavor some invasive woody plants. 

MULTIPLE THREATS

373. Rosen, P.C.; Schwalbe, C.R. 1995. Bullfrogs: Introduced 

predators in Southwestern wetlands. In: LaRoe, E.T.; 

Farris, G.S.; Puckett, C.E.; Doran, P.D.; Mac, M.J., eds. 

Our living resources: A report to the nation on the distribution, abundance, and health of U.S. plants, animals, 

and ecosystems. Washington, DC: U.S. Department 

of the Interior, National Biological Service: 452-454.

Abstract: Introduced predators, such as the bullfrog, can have 

devastating effects on faunas that evolved without equivalent 

predatory types. The bullfrog, as an exotic in the absence of 

key original enemies, attains tremendous population densities and can lead to regional extinctions and may account for 

some unexplained amphibian declines. Especially in Arizona, 

inaction could lead to the extinction of at least three native 

leopard frog species within a decade. INVASIVE SPECIES

374. Rucks, J.A. 1978. Comparison of riparian communities influenced by grazing. In: Graul, W.D.; Bissel, 

S.J., tech. coords. Lowland river and stream habitat in 

Colorado: A symposium; 1978 Oct. 4-5; Greeley, CO: 

The Wildlife Society and Colorado Audubon Council, 

Colorado Chapter. 100-113.

Abstract: The Bureau of Land Management in Colorado 

evaluated abundance and diversity of plant, bird and small 

populations in three study areas each with different grazing management practices. Significant differences in both 

abundance and diversity of each species was shown in the 

representative grazing sites. GRAZING

375. Rucks, M.G. 1984. Composition and trend of riparian 

vegetation on five perennial streams in southeastern Arizona. In: Warner, R.E.; Hendrix, K.M., eds. 

California riparian systems: Ecology, conservation, 

and productive management. Berkeley: University of 

California Press: 97-107.

Abstract: The Gila River, San Francisco River, Bonita 

Creek, Mescal Creek, and Aravaipa Creek were studied in 

the summer of 1980 to establish baseline data to be used for 

management decision and future monitoring. Cattle browsing 

appears to be the major contributing factor to the downward 

trend of broadleaf riparian communities. The only system 

in this study with an upward trend in the broadleaf riparian community is Aravaipa Creek, where cattle have been 

excluded since 1973. GRAZING
64 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

376. Sada, D. 2008. Great Basin riparian and aquatic ecosystems. In: Chambers, J.C.; Devoe, N.; Evenden, A., 

eds. Collaborative management and research in the 

Great Basin—examining the issues and developing a 

framework for action. Gen. Tech. Rep. RMRS-GTR-204. 

Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 49-52.

Abstract: This paper provides a short overview of key issues affecting the riparian and aquatic ecosystems, which 

are dominated by isolated springs in the Great Basin region. 

MULTIPLE THREATS

377. Sanders, S.D.; Flett, M.A. 1988. Montane riparian habitat 

and willow flycatchers: Threats to a sensitive environment and species. In: Abell, D.L., coord. Proceedings 

of the California riparian systems conference: Protection, management, and restoration for the 1990’s; 1988 

September 22-24; Davis, CA. Gen. Tech. Rep. PSW-110. 

Berkeley, CA: U.S. Department of Agriculture, Forest 

Service, Pacific Southwest Forest and Range Experiment Station: 262-266.

Abstract: Mountain meadows provide critical habitat for 

California’s dwindling population of Willow Flycatchers and 

for many other breeding birds. Most meadows in the western 

United States are managed for livestock or other consumptive 

uses rather than for wildlife. The potential threats to Willow 

Flycatchers and their habitat are discussed, and suggestions 

to protect and enhance mountain meadow habitat for this and 

other riparian species are offered. MULTIPLE THREATS

378. Sands, A.; Howe G. 1977. An overview of riparian forest in California: Their ecology and conservation. In: 

Johnson, R.R.; Jones, D.A., tech. coords. Importance, 

preservation and management of riparian habitat: A 

symposium; 1977 July 9; Tucson, AZ. Res. Pap. RM43. Fort Collins, CO: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Forest and Range 

Experiment Station: 98-115.

Abstract: This paper is comprised of abstracts from presentations made at the symposium on riparian forests in California: their ecology and conservation. The purpose of this 

symposium was to encourage a strong alliance of individuals 

and agencies who will work together to establish protection 

for the endangered riparian ecosystems of California. MULTIPLE THREATS

379. Sarr, D.A. 2002. Riparian livestock exclosure research 

in the western United States: A critique and some 

recommendations. Environmental Management. 30(4): 

416-526.

Abstract: This paper reviews, critiques, and provides recommendations for the improvement of riparian livestock exclosure 

research. Several initial ideas for strengthening the scientific 

basis for livestock exclosure research are presented: (1) incorporation of meta-analyses and critical reviews, (2) use of 

restoration ecology as a unifying conceptual framework, (3) 

development of long-term research programs, (4) improved 

exclosure placement/design, and (5) a stronger commitment 

to collection of pretreatment data. GRAZING

380. Schindler, D.W.; Newbury, R.W.; Beaty, K.L.; Prokopowich, J.; Ruszcynski, T.; Dalton, J.A. 1979. Effects of 

a windstorm and forest fire on chemical losses from 

forested watersheds and on the quality of receiving 

streams. Canadian Journal of Fisheries and Aquatic 

Science. 37: 328-334.

Abstract: A severe natural windstorm followed by a high 

intensity forest fire caused significant increases in runoff 

and in losses of nitrogen, phosphorus, and potassium from 

two Precambrian watersheds. Both the windstorm and the 

fire had significant effects on water and chemical yields. 

Both increased concentrations and increased flow volumes 

appear to be responsible for the increased nutrient loss. FIRE, 

WATER QUALITY

381. Schlorff, R.W.; Bloom, P.H. 1984. Importance of riparian systems to nesting Swainson’s hawk in the Central 

Valley of California. In: Warner, R.E.; Hendrix, K.M., 

eds. California riparian systems: Ecology, conservation, and productive management. Berkeley: University 

of California Press: 612-618.

Abstract: Once a common breeding bird of the Central 

Valley and elsewhere in California, the Swainson’s Hawk 

has experienced a severe population decline due to, among 

other things, loss of riparian system that provided trees for 

nest sites. The pattern of land use prevalent over the past 130 

years has reduced riparian systems of the Central Valley to 

a tiny fraction of their former extent. It will be necessary to 

maintain and restore stands of vegetation in riparian systems 

if the Swainson’s Hawk is to continue as a breeding species 

in the Central Valley. AGRICULTURE

382. Schmidly, D.J.; Ditton, R.B. 1978. Relating human 

activity and biological resources in riparian habitats 

of Western Texas. In: Johnson, R.R.; McCormick, J.F., 

tech. coords. Strategies for protection and management 

of floodplain wetlands and other riparian ecosystems. 

Gen. Tech. Rep. WO-12. Washington, DC: U.S. Department of Agriculture, Forest Service: 107-116.

Abstract: This paper discusses the recreational and wildlife 

values of riparian habitats along the Rio Grande in western 

Texas. Several human activities have the potential to impact or 

have impacted riparian resources in this region: (1) irrigation 

diversions and stream channelization, (2) reservoir construction, (3) agriculture, (4) overgrazing from domestic livestock, 

(5) introduction of exotic plants and fishes, (6) increases in 

human recreation activity, and (7) pesticide build-up. This 

paper seeks to place these impacts into broader land use 

perspective so that riparian resources can be more effectively 

managed in western Texas. MULTIPLE THREATS
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 65

383. Schmidt, L.J. 1987. Recognizing and improving riparian values: The Forest Service approach to riparian 

management. In: Mutz, K.M.; Lee, L.C., tech. coords. 

Wetland and riparian ecosystems of the American 

West: Proceedings of the eighth annual meeting of the 

Society of Wetland Scientists; 1987 May 26-29; Seattle 

WA. Denver, CO: Planning Information Corp.: 36-38.

Abstract: The Forest Service has a continuing commitment 

to conservation of riparian areas following the concept of 

“wise use.” Goals and decisions reflected in Forest Plans 

recognize the importance of riparian values. These plans 

have identified long-term objectives, guidelines, standards, 

and management requirements to protect the unique values 

of riparian areas. MULTIPLE THREATS

384. Schulz, T.T.; Leininger, W.C. 1990. Differences in riparian vegetation structure between grazed areas and 

enclosures. Journal of Range Management. 43: 295-299.

Abstract: Resource managers need to know how degraded 

riparian areas respond to changes in management, such as 

reduction and elimination of grazing. Differences in vegetation structure were examined in a montane riparian zone in 

north-central Colorado after 30 years of cattle exclusion and 

continued, but reduced, grazing pressure. In order to assess 

the changes in the riparian community, canopy coverage, 

density, and standing crop of important riparian species were 

measured in 1985 and 1986. GRAZING

385. Scott, M.L. 1988. Landscape analysis of woody riparian vegetation along a portion of the Cache La Poudre 

River, CO. In: Mutz, K.M.; Cooper, D.J; Scott, M.L.; 

Miller, L.K., tech. coords. Restoration, creation and 

management of wetland and riparian ecosystems in the 

American West: Proceedings of a symposium; 1988 

November 14-16; Denver, CO. Boulder, CO: Society of 

Wetland Scientists, Rocky Mountain Chapter: 63-70.

Abstract: Infrared aerial photography was used to assess 

the extent of woody riparian vegetation along a gradient 

from urban to agricultural areas on the Cache La Poudre 

River, a tributary of the South Platte River, CO. Although 

the aerial extent of riparian vegetation in the urban area is 

not significantly different from that in the agricultural area, 

detailed examination of land use patterns indicated a change 

in occurrence and nature of riparian vegetation from urban 

to agricultural land uses. URBANIZATION

386. Scott, M.L.; Shafroth, P.B.; Auble, G.T. 1999. Responses 

of riparian cottonwoods to alluvial water table declines. 

Environmental Management. 23(3): 347-358.

Abstract: Human demands for surface and shallow alluvial 

groundwater have contributed to the loss, fragmentation, and 

simplification of riparian ecosystems threatening dominant 

riparian Populus species. This research examines the role of 

surface and groundwater dynamics on the establishment of 

new, and maintenance of existing Populus stands. GROUNDWATER DEPLETION

387. Seavy, N.E.; Gardali, T.; Golet, G.H.; Griggs, F.T.; Howell, 

C.A.; Kelsey, R.; Small, S.L.; Viers, J.H.; Weigand, J.F. 

2009. Why climate change makes riparian restoration 

more important than ever: Recommendations for practice and research. Ecological Restoration. 27: 330-338.

Abstract: This paper addresses (1) how and why riparian 

restoration prepares ecosystems for climate change, (2) how 

riparian restoration can be enhanced to accommodate climate change, and (3) research needed to ensure that riparian 

restoration is robust to climate change. CLIMATE CHANGE

388. Sedgwick, J.A.; Knopf, F.L. 1987. Breeding bird response 

to cattle grazing of a cottonwood bottomland. Journal 

of Wildlife Management. 51: 230-237.

Abstract: This paper discusses the avian relationships and 

the impact of grazing on breeding densities of selected 

migratory birds in a plains cottonwood bottomland in 

northeastern Colorado. Moderate, late-fall grazing had no 

detectable impact on calculated densities in the six studied species. Habitat associations suggested that common 

yellowthroat and yellow-breasted chats were most unique 

and most likely to respond negatively to higher levels of 

grazing. GRAZING

389. Sedgwick, J.A.; Knopf, F.L. 1991. Prescribed grazing 

as secondary impact in a western riparian floodplain. 

Journal of Range Management. 44: 369-373.

Abstract: The effect of late-autumn cattle grazing on plant 

biomass was examined in a western Great Plains cottonwood 

riparian zone prone to catastrophic flooding every 5 to 8 

years. Following 1 year of pre-treatment data collection in 

1982, five 16-ha pastures were grazed from 1982 to 1984 and 

compared to five control pastures within the South Platte 

River floodplain in northeastern Colorado. GRAZING

390. Sewards, M.A.; Valett, H.M. 1996. Effect of livestock 

grazing on nutrient retention in a headwater stream of 

the Rio Puerco Basin. In: Shaw, D.W.; Finch, D.M., 

tech. coords. Desired future conditions for southwestern 

riparian ecosystems: Bringing interests and concerns 

together. Gen. Tech. Rep. RM-272. Fort Collins, CO: 

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

Mountain Forest and Range Experiment Station: 135-

142.

Abstract: Sediment and nutrient loss from headwater streams 

of sedimentary basins in the semi-arid Southwest have been 

attributed to both over-grazing by livestock and to climatic 

cycles that influence arroyo formation. Considerable effort 

has been directed toward the influence of livestock grazing 

on riparian species abundance and diversity. Less work has 

concentrated on the influence of livestock on in-stream processes and communities. This paper considers the interaction 

of flooding and livestock grazing on hydrologic and nutrient 

retention in a headwater stream of the Rio Puerco Basin, New 

Mexico. GRAZING
66 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

391. Shafroth, P.B.; Auble, G.T.; Stromberg, J.C.; Patten, D.T. 

1998. Establishment of woody riparian vegetation in 

relation to annual patterns of streamflow, Bill Williams 

River, Arizona. Wetlands. 18(4): 577-590.

Abstract: This paper retrospectively examines establishment 

of four woody riparian species along the Bill Williams River, 

Arizona, in the context of annual pattern of streamflow for 

the years 1993-1995. CLIMATE CHANGE

392. Shafroth, P.B.; Stromberg, J.C.; Patten, D.T. 2000. Woody 

riparian vegetation response to different alluvial water 

table regimes. Western North American Naturalist. 

60(1): 66-76.

Abstract: The objective of this study was to add to the sparse 

database of plant response to measured water table decline in 

western riparian ecosystems, by quantifying the response of 

three woody riparian species to different water table dynamics and to clarify factors that are likely to be important in 

determining plant response. The authors examined the growth 

and survival of saplings of populous, Salix and Tamarix at 

three sites with different groundwater regimes over a 3-year 

period along the Bill Williams River in western Arizona. 

INVASIVE SPECIES

393. Shanfield, A.N. 1984. Alder, cottonwood, and sycamore 

distribution and regeneration along the Nacimiento 

River, California. In: Warner, R.E.; Hendrix, K.M., 

eds. California riparian systems: Ecology, conservation, 

and productive management. Berkeley: University of 

California Press: 196-202.

Abstract: Distribution and regeneration of alder, cottonwood, 

and sycamore was assessed for much of the Nacimiento River. 

Alder, abundant along narrow reaches, had well-distributed 

height classes. Cottonwood, now rare along the river, exhibited 

low numbers of saplings; overgrazing of cattle is believed 

primarily responsible for the decline. Sycamore had good 

regeneration along narrow reaches and poor regeneration on 

broader bottomlands. GRAZING

394. Shapiro, A.M. 1984. Geographical ecology of the Sacramento Valley riparian butterfly fauna. In: Warner, 

R.E.; Hendrix, K.M., eds. California riparian systems: 

Ecology, conservation, and productive management. 

Berkeley: University of California Press: 934-941.

Abstract: The Sacramento Valley butterfly fauna is depauperate and uniform in the riparian corridor from Redding to 

the Sacramento-San Joaquin Delta. There are few obvious 

pre-American relicts and only one taxomonically recognized 

endemic. Historical reasons for these conditions are discussed. 

Land-use change and habitat fragmentation posses the greatest threats to the fauna. MULTIPLE THREATS

395. Shaw, N.L. 1991. Recruitment and growth of Pacific 

willow and sandbar willow seedlings in response to 

season and intensity of cattle grazing. In: Clary, W.P.; 

McArthur, E.D.; Bedunah, D.; Wambolt, C.L., comps. 

Proceedings of the symposium on ecology and management of riparian shrub communities; 1991 May 29-31; 

Sun Valley, ID. Gen. Tech. Rep. INT-309. Ogden, UT: 

U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 130-137.

Abstract: In this report, the effects of cattle grazing treatments 

on recruitment and growth of Pacific willow and sandbar 

willow seedlings was monitored over a 4-year period on a 

degraded low-elevation stream in the sagebrush-steppe zone 

of eastern Oregon. GRAZING

396. Shaw, N.L.; Clary, W.P. 1996. Willow establishment in 

relation to cattle grazing on an eastern Oregon stream. 

In: Shaw, D.W.; Finch, D.M., tech. coords. Desired 

future conditions for southwestern riparian ecosystems: 

Bringing interests and concerns together. Gen. Tech. 

Rep. RM-272. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 128-156.

Abstract: Natural regeneration and growth of coyote willow 

and whiplash willow were monitored from 1987 to 1993 on a 

low-elevation eastern Oregon stream degraded by more than 

a century of heavy livestock grazing. Browsing by deer each 

summer substantially reduced willow growth in all pastures, 

possibly masking treatment differences. Few willows have 

grown beyond browsing height to increase site stability and 

begin providing on-site seed sources. GRAZING

397. Shepard, B.B. 1989. Evaluation of the U.S. Forest Service 

“COWFISH” model for assessing livestock impacts on 

fisheries in the Beaverhead National Forest, Montana. 

In: Gresswell, R.E.; Barton, B.A.; Kershner, J.L., eds. 

Practical approaches to riparian resource management: 

An educational workshop; 1989 May 8-11; Billings, 

MT. U.S. Department of the Interior, Bureau of Land 

Management: 23-33.

Abstract: The COWFISH fish habitat model developed by 

the U.S. Forest Service was evaluated during 1986 and 1987 

at 43 stream sites within the Beaverhead National Forest, 

Montana, to determine the ability of the model to assess 

effects of livestock grazing on trout fisheries. Use of the 

COWFISH model by range professionals and livestock permittees increased their awareness of the effects of livestock 

grazing on aquatic resources. GRAZING

398. Sherman, H. 1989. Streambank plants vital to water 

quality. Agricultural Research. 8: 19.

Abstract: This article gives a brief description of the research conducted by T. Svejcar of the USDA-ARS to reduce 

damage to streambanks caused by human activities, such as 

livestock grazing, mining, road building and recreational 

uses. MULTIPLE THREATS
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 67

399. Simonds, G. 1988. Riparian habitat: Deseret’s point of 

view. In: Mutz, K.M.; Cooper, D.J; Scott, M.L.; Miller, 

L.K., tech. coords. Restoration, creation and management of wetland and riparian ecosystems in the American 

West: Proceedings of a symposium; 1988 November 

14-16; Denver, CO. Boulder, CO: Society of Wetland 

Scientists, Rocky Mountain Chapter: 178-179.

Abstract: This paper provides a brief description of how 

riparian areas in the Deseret Ranch located in northeastern 

Utah have changed in the past. GRAZING

400. Skagen, S.K.; Kelley, J.F.; van Riper, C., III; Hutto, 

R.L.; Finch, D.M.; Krueper, D.J.; Melcher, C.P. 2005. 

Geography of spring landbird migration through riparian 

habitats in Southwestern North America. The Condor. 

107: 212–227.

Abstract: This project represents a synthesis of several 

western migration studies, is an initial step in identifying 

regions and landscapes important during migration stopover, 

and may enhance efforts for conserving migration habitats 

of landbirds that breed in Southwestern North America. 

MULTIPLE THREATS

401. Smith, D.M.; Finch, D.M.; Hawksworth, D.L. 2009a. 

Black-Chinned Hummingbird nest-site selection and 

nest survival in response to fuel reduction in a southwestern riparian forest. The Condor. 111(4): 641-652.

Abstract: The Black-Chinned Hummingbird nests primarily 

in riparian forests where humans have altered the structure 

and composition of this habitat. There have been few studies 

regarding hummingbirds’ nest survival, have been limited in 

scale and have not addressed effects of habitat change. This 

study examines the response of Black-Chinned Hummingbirds 

to habitat alterations caused by fuel reduction. The researchers found a negative relationship of nest height and survival 

in cottonwood, the substrate most commonly used after fuel 

reduction. They suggest replacing exotic vegetation with native vegetation of low stature such as New Mexico olive to 

prevent decreases in nest survival. FOREST HARVESTING

402. Smith, D.M.; Kelly, J.F.; Finch, D.M. 2007. Avian nest 

box selection and nest success in burned and unburned 

southwestern riparian forest. Journal of Wildlife Management. 71: 411-421.

Abstract: This study evaluated the effects of high-intensity 

spring and summer wildfire on the quality of breeding bird 

habitat in the Middle Rio Grande Valley. The results show 

that certain bird species will successfully breed in burned 

riparian forest if nest sites are available. FIRE

403. Smith, D.M.; Finch, D.M.; Gunning, C.; Jemison, R.; 

Kelly, J.F. 2009b. Post-wildfire recovery of riparian 

vegetation during a period of water scarcity in the 

Southwestern USA. Fire Ecology Special Issue. 5(1): 

38-55.

Abstract: The observations of this study suggest that in 

the absence of ideal hydrologic and climatic conditions, 

fire can reduce cottonwood density in the bosque (riparian 

forest) along the Middle Rio Grande of central New Mexico 

and promote the spread of saltcedar. Further, it suggests 

that the increasingly xeric conditions predicted under most 

climate change scenarios could result in greater recovery of 

exotic saltcedar over native vegetation. FIRE, INVASIVE 

SPECIES,CLIMATE CHANGE

404. Smith, J.J. 1988. Recovery of riparian vegetation on 

an intermittent stream following removal of cattle. 

In: Abell, D.L., coord. Proceedings of the California 

riparian systems conference: Protection, management, 

and restoration for the 1990’s; 1988 September 22-

24; Davis, CA. Gen. Tech. Rep. PSW-110. Berkeley, 

CA: U.S. Department of Agriculture, Forest Service, 

Pacific Southwest Forest and Range Experiment Station: 217-221.

Abstract: In 1984-1987 the recovery of riparian willows 

and sycamores was studied on two short, intermittent stream 

sections in a newly acquired portion of a state park in central California. Prior to removal of cattle in 1983, the plots 

contained mature sycamores, one young sycamore and five 

willows. By 1985 over 320 willows, 16 sycamores and 1 cottonwood had appeared, and basal sprouts had developed on 

the mature sycamores. Young willows and sycamores grew 

slowly, and establishment and growth generally ceased as 

surface flows disappeared. Because of slow growth at the 

sites, a significant willow corridor is probably only possible 

in the absence of cattle browsing. GRAZING

405. Smith, M.A.; Rodgers, J.D.; Dodd, J.L.; Skinner, Q.D. 

1992. Habitat selection by cattle along an ephemeral 

channel. Journal of Range Management. 45: 385-390.

Abstract: Because of widespread concern about cattle 

grazing effects on riparian zones of public lands, seasonal 

habitat selection by cattle was studied along a cold desert 

area ephemeral waterway of north-central Wyoming. Little 

is known of grazing effects on ephemeral streams compared 

to perennial streams. Cattle activity was monitored in small 

pastures and a surrounding large allotment in spring, summer, 

and fall. Observations included activity and habitat where it 

occurred. Concomitantly, utilization levels, protein content, 

and dry matter content of forages were determined in the 

small pastures. GRAZING

406. Snider, G.B.; Daugherty, P.J.; Medina, A.L. 1998. An 

ecological and economic approach for analyzing the 

costs and benefits of riparian restoration projects. In: 

Hydrology and water resources in Arizona and the 

Southwest. Arizona-Nevada Academy of Science: 47-50.

Abstract: Successful restoration of threatened riparian ecosystems should be analyzed using a combined ecological and 

economic approach. The disciplines of ecology and economics 
68 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

need to recognize the mutualistic relationship between these 

biophysical and socioeconomic systems in order to achieve 

successful restoration. This requires a shift of focus from a 

narrow single-species approach to the integrity of the entire 

system recognizing the mutualistic connectedness between 

ecology and economics. MULTIPLE THREATS

407. Snyder, W.D. 1988. Stem cutting propagation of woody 

phreatophytes in eastern Colorado. In: Mutz, K.M.; 

Cooper, D.J; Scott, M.L.; Miller, L.K., tech. coords. 

Restoration, creation and management of wetland and 

riparian ecosystems in the American West: Proceedings of a symposium; 1988 November 14-16; Denver, 

CO. Boulder, CO: Society of Wetland Scientists, Rocky 

Mountain Chapter: 151-156.

Abstract: Seven species of native woody phreatophytes and 

one exotic species were planted using stem cutting techniques 

at sites with relatively high groundwater levels along eastern 

Colorado rivers from 1984 to 1986. This paper reviews and 

evaluates stem cutting propagation trial in eastern Colorado. 

MULTIPLE THREATS

408. Sommarstorm, S. 1984. Riparian regulation: Random, 

redundant or rational? In: Warner, R.E.; Hendrix, K.M., 

eds. California riparian systems: Ecology, conservation, 

and productive management. Berkeley: University of 

California Press: 274-280.

Abstract: The purpose of this paper is (1) to identify the 

primary local, State, and Federal regulatory agencies and 

laws responsible for conserving riparian systems on private 

lands; (2) to analyze these regulatory responsibilities from 

the perspective of the regulators as well as those regulated; 

(3) to propose some improvements in the current regulatory approach; and (4) to stimulate discussion regarding the 

traditional assumption about environmental regulation as a 

conservation tool. Further, this paper discusses the various 

threats to riparian systems from a regulatory point of view. 

MULTIPLE THREATS

409. Spear, M.J.; Mullins, C.L. 1987. Riparian habitat of the 

Middle Rio Grande—A case study for more effective 

protection. In: Mutz, K.M.; Lee, L.C., tech. coords. 

Proceedings of the eighth annual meeting of the Society of Wetland Scientists; 1987 May 26-29; Seattle 

WA. Denver, CO: Planning Information Corp.: 45-47.

Abstract: One of the most extensive remaining gallery 

cottonwood forests in the Southwest is located along the 

Middle Rio Grande. This riparian zone supports a diversity 

and density of wildlife unmatched by other habitat types in 

the Southwest. However, Federal, State and local programs 

to protect wetlands, of which riparian ecosystems are a part, 

have been ineffective in the Middle Rio Grande. Accordingly, 

the unique value of this area makes it an ideal candidate for 

special attention or protection. MULTIPLE THREATS

410. Spencer, D.F.; Ksander, G.G.; Whitehand, L.C. 2005. 

Spatial and temporal variation in RGR and leaf quality of a clonal riparian plant: Arundo donax. Aquatic 

Botany. 81: 27–36.

Abstract: The purpose of this study was to determine if 

growth, plant quality, and nutrient availability varied temporally and spatially in a northern California population of 

Arundo donax, which has invaded riparian zones in California 

where it acts as a transformer species. Because plant growth 

and leaf quality influence the effectiveness of management 

techniques, this study sought to determine if these characters 

varied. INVASIVE SPECIES

411. Spotts, R. 1988. Conflicts in river management: A conservationist’s perspective on Sacramento River riparian 

habitats—impacts, threats, remedies, opportunities and 

consensus. In: Abell, D.L., coord. Proceedings of the 

California riparian systems conference: Protection, 

management and restoration for the 1990’s; 1988 September 22-24; Davis, CA. Gen. Tech. Rep. PSW-110. 

Berkeley, CA: U.S. Department of Agriculture, Forest 

Service, Pacific Southwest Forest and Range Experiment Station: 521-525.

Abstract: This paper provides a conservationist’s perspective on how resource loses could be stopped and eventually 

reversed, through a combination of less-damaging bank 

protection methods, reliable mitigation for unavoidable 

impacts, willing seller acquisitions and restoration projects. 

MULTIPLE THREATS

412. Starnes, W.C. 1995. Colorado River Basin fishes. In: 

LaRoe, E.T.; Farris, G.S.; Puckett, C.E.; Doran, P.D.; 

Mac, M.J., eds. Our living resources: A report to the 

nation on the distribution, abundance, and health of 

U.S. plants, animals, and ecosystems. Washington, DC: 

U.S. Department of the Interior, National Biological 

Service: 149-152.

Abstract: This paper examines the trends of the population 

make up of the Colorado River Basin fishes: native versus 

non-native species. The author states that the abundance of 

non-native fishes can be an indicator of the degree of alteration of the Colorado River ecosystem and can impair future 

studies of biodiversity. INVASIVE SPECIES

413. Stednick, J.D. 2010. Effects of fuel management practices 

on water quality. In: Elliot, W.J.; Miller, I.S.; Audin, 

L., eds. Cumulative watershed effects of fuel management in the western United States. Gen. Tech. Rep. 

RMRS-GTR-231. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Research 

Station: 149-163.

Abstract: Fuel management practices occur infrequently 

ranging from once every year to once over several decades. 

These activities, which influence riparian ecology, should be 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 69

implemented with best management practices to minimize 

or prevent water quality changes or non-point source pollution. FIRE

414. Stern, V.M. 1984. Pest and beneficial insects associated 

with agriculture and riparian systems. In: Warner, 

R.E.; Hendrix, K.M., eds. California riparian systems: 

Ecology, conservation, and productive management. 

Berkeley: University of California Press: 970-982.

Abstract: Vast changes have occurred in the California landscape over the past 100 years. In agriculture, many of these 

changes favor the buildup of pest populations over biological 

control. The manipulation of pest populations is a complex 

study is applied ecology. AGRICULTURE

415. Stevens, L.E.; Stacey, P.B.; Jones, A.L.; Duff, D.; Gourley, 

C.; Catlin, J.C. 2005. A protocol for rapid assessment 

of southwestern stream-riparian ecosystems. In: 

van Riper III, C.; Mattson, D.J., eds. The Colorado 

Plateau II: Biophysical, socioeconomic and cultural 

research. Tucson, AZ: The University of Arizona Press: 

397-420.

Abstract: This paper presents an improved method for rapid 

stream-riparian assessment, measuring the functioning condition of these habitats. MULTIPLE THREATS

416. Stevens, R.; McArthur, E.D.; Davis, J.N. 1991. Reevaluation of vegetative cover changes, erosion, and sedimentation on two watersheds—1912-1983. In: Clary, 

W.P.; McArthur, E.D.; Bedunah, D.; Wambolt, C.L., 

comps. Proceedings of the symposium on ecology and 

management of riparian shrub communities; 1991 May 

29-31; Sun Valley, ID. Gen. Tech. Rep. INT-309. Ogden, 

UT: U.S. Department of Agriculture, Forest Service, 

Intermountain Research Station: 123-128.

Abstract: This paper outlines two approaches to watershed 

restoration and their results in the two Ephraim Canyon 

watersheds—Watersheds A and B—by evaluating changes 

in cover type, erosion, and sedimentation in the years 1952, 

1958, 1961, and 1983. MULTIPLE THREATS

417. Stone, K.R.; Pilliod, D.S.; Dwire, K.A.; Rhoades, C.C.; 

Wollrab, S.P.; Young, M.K. 2010. Fuel reduction management practices in riparian areas of the Western USA. 

Environmental Management. 46: 91-100.

Abstract: Two decades of uncharacteristically severe wildfires have caused government and private land managers to 

actively reduce hazardous fuels to lessen wildfire severity in 

western forests, including riparian areas. Because riparian 

fuel treatments are a fairly new management strategy, this 

paper documents the frequency and extent on Federal lands 

in the western United States and found that well-designed 

monitoring of the consequences of riparian fuels treatments 

on fuel loads, fire risk, and ecological effects is needed to 

provide a scientifically defensible basis for the continued 

and growing implementation of these treatments. FOREST 

HARVESTING, FIRE

418. Storch, R.L. 1978. Livestock/streamside management 

programs in eastern Oregon. In: Cope, O.B., ed. Proceedings of the forum—grazing and riparian/stream 

ecosystems; 1978 Nov. 3-4; Denver, CO. Arlington, 

VA: Trout Unlimited: 56-59.

Abstract: Uncontrolled livestock grazing has seriously affected the water quality of streams. Indiscriminate use of streams 

by livestock results is breaking down the streambanks, eating 

and trampling shrubs that shade the streams and/or provide 

habitat for wildlife, and disturbing the stream bottoms. The 

effects of such use have been erosion of streambanks, higher 

water temperatures, increased sedimentation, soil compaction, 

and reduction of quality and quantity of forage. GRAZING

419. Strahan, J. 1984. Regeneration of riparian forests of the 

Central Valley. In: Warner, R.E.; Hendrix, K.M., eds. 

California riparian systems: Ecology, conservation, 

and productive management. Berkeley: University of 

California Press: 58-67.

Abstract: Riparian forests of the Sacramento River have 

an overstory and a regeneration pattern corresponding to 

the successional stage and fluvial landform associated with 

the forest stands. Land use and water development projects 

alter fluvial landforms and fluvial events to create changes in 

forest composition and regeneration. MULTPLE THREATS

420. Stromberg, J.C. 2001. Restoration of riparian vegetation in the southwestern United States: Importance of 

flow regimes and fluvial dynamism. Journal of Arid 

Environments. 49: 17-34.

Abstract: This paper describes changes that have occurred 

within riparian ecosystems of the southwestern United States, 

reviews the role of key environmental factors that structure 

riparian plant communities, and assesses various ways in 

which riparian vegetation can be restored by naturalizing 

ecological processes. MULTIPLE THREATS

421. 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.

Abstract: A major threat to riparian ecosystems is groundwater depletion. This paper confirms the importance of 

hydrologic factors, notably depth to groundwater and inundation frequency, in structuring the San Pedro River plant 

community. Utilizing a space-time continuum model the 

authors predict the eventual “desertification” of riparian flora 

(i.e. loss or reduction of cover of species based on their probability of occurrence in wetlands) as one potential response 

to groundwater decline. GROUNDWATER DEPLETION
70 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

422. Stromberg, J.C.; Tress, J.A.; Wilkins, S.D.; Clark, S.D. 

1992. Response of velvet mesquite to groundwater decline. Journal of Arid Environments. 23: 45-58.

Abstract: Mesquite bosques are groundwater-dependent 

riparian woodlands that were once widespread in the American Southwest. Temporal and spatial variation in plant water 

potential, leaflet size, leaflet number, canopy height, and 

live and dead vegetation volume all indicate that the bosque 

requires a shallow aquifer and that bosque traits change continually with groundwater depth. This paper quantifies the 

relationships between groundwater depths and bosque traits 

using an ephemeral creek in the Sonoran Desert. GROUNDWATER DEPLETION

423. Stromberg, J.C.; Wilkins, S.D.; Tress, J.A. 1993. Vegetation-hydrology models: Implications for management of 

Prosopis velutina (velvet mesquite) riparian ecosystems. 

Ecological Applications. 3(2): 307-314.

Abstract: Velvet mesquite forests are one of the many types 

of arid-land riparian ecosystems that are threatened by 

groundwater pumping and other types of water development. 

The authors developed vegetation and hydrologic models for 

velvet mesquite stands across a xeric to mesic moisture gradient that can be used in the management of these threatened 

ecosystems. They found that stand structure was strongly 

related to water availability. The application of these models 

includes the ability to identify minimum water table depths for 

riparian stand maintenance and to detect stressful hydrologic 

conditions, via water potential measurements, before the onset 

of structural degradation. GROUNDWATER DEPLETION

424. Stromberg, J.C.; Beauchamp, V.B.; Dixon, M.D.; Lite, 

S.J.; Paradzick, C. 2007a. Importance of low-flow and 

high-flow characteristics to restoration of riparian vegetation along rivers in arid southwestern United States. 

Freshwater Biology. 52(4): 651–679.

Abstract: This paper addresses relationships between stream 

flow regimes and riparian vegetation of the arid southwestern 

United States, focusing mainly on rivers within Arizona’s Gila 

River drainage basin. Specifically, it examines relationships 

of low flows and high flows with plant species diversity, 

plant species composition, and landscape heterogeneity. 

DROUGHT, FLOODS

425. Stromberg, J.C.; Briggs, M.; Gourley, C.; Scott, M; 

Shafroth, P.; Stevens, L. 2004. Chapter 6: Human alterations of ecosystems. In: Baker, M.B., Jr.; Ffolliott, P.F.; 

DeBano, L.F.; Neary, D.G., eds. Hydrology, ecology and 

management of riparian areas in the southwestern United 

States. Boca Raton, FL: Lewis Publishers: 99-126.

Abstract: This chapter discusses the ways in which Southwest 

riparian ecosystems have been changed by water management. Special attention is given to dams and groundwater 

pumping, which can act synergistically to change riparian 

biota, sediment dynamics, and water flow. Restoration strategies for hydrologically altered riparian zones are discussed. 

MULTIPLE THREATS

426. Stromberg, J.C.; Lite, S.J.; Marler, R.; Paradzick, C.; 

Shafroth, P.B.; Shorrock, D.; White, J.M.; White, M.S. 

2007b. Altered stream-flow regimes and invasive plant 

species: The Tamarix case. Global Ecology and Biogeography. 16(3): 381–393.

Abstract: This paper aims to test the hypothesis that anthropogenic alteration of streamflow regimes is a key driver 

of compositional shifts from native to introduced riparian 

plant species. Results indicate that Populus and Salix were 

the dominant pioneer trees along the reaches with perennial 

flow and a natural flood regime. In contrast, Tamarix had 

high abundance (patch area and basal area) along reaches with 

intermittent stream flows (caused by natural and cultural factors), as well as those with dam-regulated flows. INVASIVE 

SPECIES, DAM CONSTRUCTION

427. Stromberg-Wilkins, J.C.; Patten, D.T. 1987. Mast cropping 

in Arizona walnut. In: Mutz, K.M.; Lee, L.C., tech. coords. Wetland and riparian ecosystems of the American 

West: Proceedings of the eighth annual meeting of the 

Society of Wetland Scientists; 1987 May 26-29; Seattle 

WA. Denver, CO: Planning Information Corp.: 309-314.

Abstract: Arizona walnut is a facultative wetland tree, which 

grows is a variety of riparian habitats. Populations exhibit 

different degrees of masting, that is, periodic production of 

large crops. Stream flow characteristics and moisture availability are associated with masting patterns among walnut 

populations. DROUGHT

428. Stuber, R.J. 1985. Trout habitat, abundance and fishing 

opportunities in fenced vs unfenced riparian habitat 

along Sheep Creek, CO. In: Johnson, R.R.; Ziebell, 

C.D.; Patton, D.R.; Ffolliott, P.F.; Hamre, R.H., tech. 

coords. Riparian ecosystems and their management: 

Reconciling conflicting uses. First North American 

riparian conference; 1985 April 16-18; Tucson, AZ. Gen. 

Tech. Rep. RM-120. Fort Collins, CO: U.S. Department 

of Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 310-314.

Abstract: Fencing was used to protect 40 hectares of riparian stream habitat along 2.5 km of Sheep Creek, CO, from 

adverse impacts due to heavy streamside recreation use and 

cattle grazing. Fish habitat within the fenced area was narrower, deeper, had less streambank alteration, and better 

streamside vegetation than comparable unfenced section. 

There was a higher proportion of non-game fish present in 

unfenced sections. GRAZING, RECREATION
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 71

429. Studenmund, R.G. 1993. The Nature Conservancy’s 

Sweetwater River project. In: Tellman, B.; Cortner, 

H.J.; Wallace, M.G.; DeBano, L.F.; Hamre, R.H., tech. 

coords. Riparian management: Common threads and 

shared interests. A western regional conference on river 

management strategies; 1993 Feb 4-6; Albuquerque, 

NM. Gen. Tech. Rep. RM-226. Fort Collins, CO: U.S. 

Department of Agriculture Forest Service, Rocky Mountain Forest and Range Experiment Station: 356-358.

Abstract: This paper provides a background on the Sweetwater River in Wyoming and gives the reason for the decline 

of its riparian degradation. Further, it describes the Nature 

Conservancy’s efforts to restore the riparian ecosystem of 

the river. MULTIPLE THREATS

430. Sudbrock, A. 1993. Fighting back: An overview of the 

invasion, and a low-impact way of fighting it. Restoration and Management. 11: 31-34.

Abstract: This paper offers an overview of the ecological 

problems related to saltcedar and recommends a proven, 

low-impact method for eradicating it. INVASIVE SPECIES

431. Sun, K. 1987. Building and restoring riparian zones 

through ranch management. In: Mutz, K.M.; Lee, L.C., 

tech. coords. Wetland and riparian ecosystems of the 

American West: Proceedings of the eighth annual 

meeting of the Society of Wetland Scientists; 1987 May 

26-29; Seattle WA. Denver, CO: Planning Information 

Corp.: 271-275.

Abstract: The condition of the Sweetwater Valley in Wyoming 

during the late 1800s is well documented. Pictures and pioneer journals characterize the overgrazed condition. Shifting 

sand bars, lack of brush and trees and unstable banks speak 

of the poor stream condition. Recent pictures show abundant willows, grassy banks and narrower stabilized stream. 

Flood irrigation has raised the water table, and return flow 

has helped to stabilize the flow during dry months. Careful 

grazing practices permit good use of forage and wildlife is 

abundant. GRAZING

432. Sun, K. 1988. Historical perspective of riparian areas 

along the Oregon Trail. In: Mutz, K.M.; Cooper, D.J; 

Scott, M.L.; Miller, L.K., tech. coords. Restoration, 

creation and management of wetland and riparian 

ecosystems in the American West: Proceedings of 

a symposium; 1988 November 14-16; Denver, CO. 

Boulder, CO: Society of Wetland Scientists, Rocky 

Mountain Chapter: 71-72.

Abstract: This paper provides a brief description of how 

western riparian areas along the Oregon Trail have changed 

in the past 200 years. Several photographs are presented. 

MULTIPLE THREATS

433. Svejcar, T. 1997a. Riparian zones: 1) What are they and 

how do they work? Rangelands. 19(4): 4-7.

Abstract: This is an informative paper that defines and describes riparian zones. It covers the importance of riparian 

zones, their structure and function, and the dynamic nature 

and long-term cycles of riparian ecosystems. MULTIPLE 

THREATS

434. Svejcar, T. 1997b. Riparian zones: 2) History and human 

impacts. Rangelands. 19(4): 8-12.

Abstract: This paper outlines the history of human impacts 

on riparian zones. Svejcar focuses on post-settlement impacts 

covering the broad categories of beaver populations removal, 

livestock introduction, herbicide use, mechanical treatment 

application, logging, mining, and recreation. Other factors 

that are mentioned include human induced changes in upland vegetation and alien species introduction. MULTIPLE 

THREATS

435. Swanson F.J.; Fredriksen, R.L. 1982. Sediment routing 

and budgets: Implications for judging impacts of forestry practices. In: Swanson, F.J.; Janda, R.J.; Dunne, 

T.; Swanston, D.N., tech. eds. Workshop on sediment 

budgets and routing in forest drainage basins. Gen. 

Tech. Rep. PNW-141. Portland OR: U.S. Department 

of Agriculture Forest Service, Pacific Northwest Forest 

and Range Experiment Station. 129-137

Abstract: Sediment budget and routing studies offer some 

improvements over traditional studies of small drainage 

basin manipulations and individual erosion processes for 

analysis of impacts of forestry practices on soil erosion from 

hillslopes and sedimentation in streams. Quantification of 

long-term (century) and short-term (decades) impacts waits 

a more detailed analysis of the dynamics of sediment storage 

in stream channels and at hillslope sites prone to failure by 

debris avalanches. MULTIPLE THREATS

436. Swanson, F.J.; Lienkaemper, G.W. 1978. Physical consequences of large organic debris in Pacific Northwest 

streams. Gen. Tech. Rep. PNW-69. Portland, OR: U.S. 

Department of Agriculture Forest Service, Pacific 

Northwest Forest and Range Experiment Station: 12 p.

Abstract: Large organic debris in streams controls the 

distribution of aquatic habitats, the routing of sediment 

through stream systems and the stability of streambed and 

banks. Management activities directly alter debris loading 

by addition or removal of material and indirectly by increasing the probability of debris torrents and removing standing 

streamside trees. MULTIPLE THREATS

437. Swanson, S. 1988. Using stream classification to prioritize riparian rehabilitation after extreme events. 

In: Abell, D.L., coord. Proceedings of the California 

riparian systems conference: Protection, management, 
72 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

and restoration for the 1990’s; 1988 September 22-24; 

Davis, CA. Gen. Tech. Rep. PSW-110. Berkeley, CA: 

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

Southwest Forest and Range Experiment Station: 96-101.

Abstract: Riparian grazing can be managed in a variety of 

ways to avoid detrimental effects. A useful alternative to a 

riparian exclosure is a riparian pasture that can be managed 

for optimum riparian resource values. GRAZING

438. Swanston, D.N. 1980. Influence of forest and rangeland 

management on anadromous fish habitat in western 

North America: Impacts of natural events. PNWGTR-104. Portland, OR: U.S. Department of Agriculture 

Forest Service, Pacific Northwest Forest and Range 

Experiment Station: 27 p.

Abstract: Natural events affecting vegetative cover and the 

hydrology and stability of a stream and its parent watershed 

are key factors influencing the quality of anadromous fish 

habitat. High intensity storms, drought, soil mass movement, 

and fire have the greatest impacts. Wind, stream icing, and 

the influence of insects and disease are important locally. 

MULTIPLE THREATS

439. Swenson, E.A. 1988. Progress in the understanding of 

how to reestablish native riparian plants in New Mexico. 

In: Mutz, K.M.; Cooper, D.J; Scott, M.L.; Miller, L.K., 

tech. coords. Restoration, creation and management of 

wetland and riparian ecosystems in the American West: 

Proceedings of a symposium; 1988 November 14-16; 

Denver, CO. Boulder, CO: Society of Wetland Scientists, 

Rocky Mountain Chapter: 144-150.

Abstract: This paper reports on the development of a dormant pole planting technique and cites the results of several 

operational projects. In addition, species evaluation and 

superior accession selections are described. A description 

of the deteriorated riparian vegetation is included as well. 

MULTIPLE THREATS

440. Szaro, R.C.; Belfit, S.C.; Aitkin, J.K.; Rinne, J.N. 1985. 

Impact of grazing on a riparian Garter Snake. In: 

Johnson, R.R.; Ziebell, C.D.; Patton, D.R.; Ffolliott, 

P.F.; Hamre, R.H., tech. coords. Riparian ecosystems 

and their management: Reconciling conflicting uses. 

First North American riparian conference; 1985 April 

16-18; Tucson, AZ. Gen. Tech. Rep. RM-120. Fort 

Collins, CO: U.S. Department of Agriculture, Forest 

Service, Rocky Mountain Forest and Range Experiment 

Station: 359-363.

Abstract: Numbers of wandering garter snakes were significantly higher where cattle grazing was excluded than along 

grazed portions of the Rio de las Vacas. Differences can be 

attributed to the regeneration of streamside vegetation and 

increased amount of organic debris. GRAZING

441. Tainter, J.A.; Tainter, B.B. 1996. Riverine settlement 

in the evolution of prehistoric land-use systems in the 

Middle Rio Grande Valley, New Mexico. In: Shaw, D.W.; 

Finch, D.M., tech. coords. Desired future conditions for 

southwestern riparian ecosystems: Bringing interests 

and concerns together. Gen. Tech. Rep. RM-272. Fort 

Collins, CO: U.S. Department of Agriculture, Forest 

Service, Rocky Mountain Forest and Range Experiment 

Station: 22-32.

Abstract: This paper describes changes in prehistoric landuse in part of the Middle Rio Grande Valley, New Mexico. 

Processes of economic change, land-use intensification, and 

regional abandonment suggest that there were periods of 

significant prehistoric disturbance to both upland and valley 

ecosystems. MULTIPLE THREATS

442. Taylor, D.M. 1986. Effects of cattle grazing on passerine birds nesting in riparian habitat. Journal of Range 

Management. 39: 254-258.

Abstract: Nine transects, in areas with different histories 

of cattle grazing, were established along the Blitzen River 

in Oregon. Counts of birds and measurements of vegetation 

were made in the summers of 1981 and 1982. Increased frequency of grazing on an annual basis correlated significantly 

with decreases in bird abundance, shrub volume, and shrub 

heights. The longer the time since a transect was last grazed 

correlated significantly with increases in bird abundance, 

shrub volume, and shrub heights. Bird abundance increased 

significantly with increased shrub volume and taller shrub 

heights. Bird species richness decreased with increased grazing. Bird counts were 5 to 7 times higher on an area ungrazed 

since 1940 than on 2 areas grazed annually until 1980, and 

11 to 13 times higher than on a transect severely disturbed by 

extensive grazing and dredging activities. Disturbances from 

camper activities also appeared to reduce bird populations. 

MULTIPLE THREATS

443. Tellman, B.; Yarde, R.; Wallace, M.G. 1997. Arizona’s 

changing rivers: How people have affected the rivers. 

Tucson: University of Arizona, College of Agriculture, 

Water Resources Research Center: 198 p.

Abstract: This book describes how humans have been changing Arizona’s Rivers for centuries and how the changes since 

the mid-19th century have been more profound than earlier 

changes. The great dams on the Colorado River are the most 

visible of those modern activities. Arizona’s population explosion of the 20th century accelerated those changes, many of 

which are irreversible. MULTIPLE THREATS

444. Tettemer, J.M. 1987. A joint venture to preserve, enhance 

and maintain wetlands and riparian systems. In: Mutz, 

K.M.; Lee, L.C., tech. coords. Wetland and riparian 

ecosystems of the American West: Proceedings of 

the eighth annual meeting of the Society of Wetland 

Scientists; 1987 May 26-29; Seattle WA. Denver, CO: 

Planning Information Corp.: 286-288.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 73

Abstract: This paper observes that wetlands preservation 

through a joint venture is a practical alternative to the current conflicts. It identifies the objectives for riparian and 

wetland systems, obstacles in reaching those objectives, and 

the developer’s interests. It encourages master planning of 

riparian and wetlands areas. MULTIPLE THREATS

445. Theobald, D.M.; Merritt, D.M; Norman, J.B., III. 2010. 

Assessment of threats to riparian ecosystems in the 

western U.S. Prepared for the Western Environmental 

Threats Assessment Center, Pineville, OR: 56 p.

Abstract: This report provides an initial, coarse-scale assessment of historical, current and future threats to streams 

and riparian areas in the western United States. MULTIPLE 

THREATS

446. Tiedemann, A.R.; Helvey, J.D.; Anderson, T.D. 1978. 

Stream chemistry and watershed nutrient economy following wildfire and fertilization in Eastern Washington. 

Journal of Environmental Quality. 7: 580-588.

Abstract: During the first 3 years after a severe wildfire in 

1970, maximum concentration of nitrate-N instream water 

increased from pre-fire levels on a burned, unfertilized watershed and on two watersheds that were burned and fertilized. Relative background conditions and levels observed in 

the control stream, the fire exerted protracted impact on the 

chemistry of these streams. Results, however, indicate that 

fire and fertilization exerted negligible effects on chemical 

water quality for municipal use. FIRE, WATER QUALITY

447. Tiner, R.W., Jr. 1984. Wetlands of the United States: 

Current status and recent trends. National Wetlands 

Inventory. U.S. Department of the Interior, U.S. Fish 

and Wildlife Service. 59 p.

Abstract: This report identifies the current status of U.S. 

wetlands and major areas where wetlands are in greatest 

jeopardy from the national standpoint. It also presents regional 

and national information on wetland trends, including past 

and current threats. MULTIPLE THREATS

448. Tremble, M. 1993. The Little Colorado River. In: Tellman, B.; Cortner, H.J.; Wallace, M.G.; DeBano, L.F.; 

Hamre, R.H., tech. coords. Riparian management: Common threads and shared interests. A western regional 

conference on river management strategies; 1993 Feb 

4-6; Albuquerque, NM. Gen. Tech. Rep. RM-226. Fort 

Collins, CO: U.S. Department of Agriculture Forest 

Service, Rocky Mountain Forest and Range Experiment 

Station: 283-289.

Abstract: This paper describes the Little Colorado River, 

its watershed, riparian vegetation, and the threats to the 

river, which includes river alteration caused by saltcedar. 

INVASIVE SPECIES

449. Trimble, S.W.; Mendel, A.C. 1995. The cow as a geomorphic agent: A critical review. Geomorphology. 13: 

233-253.

Abstract: The authors of this paper believe that both empirical studies and deterministic modeling can provide insights 

as to the effects of grazing on geomorphology. GRAZING

450. Troendle, C.A.; Olsen, W.K. 1992. Potential effects of 

timber harvest and water management on streamflow 

dynamics and sediment transport. In: Covington, W.W.; 

DeBano, L.F., tech. coords. Sustainable ecological 

systems: Implementing an ecological approach to land 

management; 1993 July 12-15; Flagstaff, AZ: Gen. Tech. 

Rep. RM-247. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 34-41.

Abstract: This paper addresses the flow parameters that 

influence sediment transport and the implications of changing flow dynamics, whether from flow or forest management, 

and the effect it has on the transport process. MULTIPLE 

THREATS

451. Tyree, M.T.; Kolb, K.J.; Rood, S.B.; Patiño, S. 1994. 

Vulnerability to drought-induced cavitation of riparian 

cottonwoods in Alberta: A possible factor in the decline 

of the ecosystem? Tree Physiology. 14: 455-466.

Abstract: This paper examines the vulnerability of xylem 

to loss of hydraulic conductivity caused by drought induced 

cavitation of three riparian cottonwood species. These species suffer a 50% loss of hydraulic conductivity when xylem 

pressure fell to –0.7 MPa for Populus deltoides and –0.1.7 

MPa for P. balsamifera and P. augustifolia, making them the 

three most vulnerable tree species reported so far in North 

America. The authors also address the role of drought-induced 

xylem dysfunction to the decline of riparian ecosystems in 

dammed rivers. DROUGHT

452. Unsicker, J.E.; White, C.A.; James, M.R.; Kuykendall, 

J.D. 1984. Protecting stream environment zones to 

preserve water quality in the Lake Tahoe Basin. In: 

Warner, R.E.; Hendrix, K.M., eds. California riparian 

systems: Ecology, conservation, and productive management. Berkeley: University of California Press: 808-814.

Abstract: Stream environment zones can provide effective 

natural removal of pollutants in precipitation runoff, which 

would otherwise adversely affect the waters of Lake Tahoe. 

Human disturbance—mostly development and related activities—of some stream environment zones in the Tahoe Basin 

has drastically reduced their treatment capability. WATER 

QUALITY

453. Uresk, D.W.; Boldt, C.E. 1986. Effect of cultural treatments on regeneration of native woodlands on the 

Northern Great Plains. Prairie Naturalist. 18(4): 193-202.
74 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

Abstract: The objectives of this study were to determine the 

response of shrubs and trees in the northern Great Plains to 

livestock grazing and exclusion of grazing and in unthinned 

woodlands and thinned woodlands in which low vigor trees 

were removed and woody plants transplanted. A riparianlike woodland system in the upper reaches of Magpie Creek 

drainage near Belfield was selected. GRAZING, FOREST 

HARVESTING

454. U.S. Department of the Interior. 2005. Water management 

of the regional aquifer in the Sierra Vista subwatershed, 

Arizona—2004 Report to Congress. Upper San Pedro 

Partnership: 36 p.

Abstract: The report first discusses and defines the concept 

of sustainable yield and sets specific goals for the reduction 

of ground-water overdraft. The report then presents specific 

planned water-use management and conservation measures 

intended to facilitate the achievement of sustainable yield. 

The water-management measures presented in this report 

were either selected from among the options the Partnership 

has previously evaluated, or are measures implemented by 

individual members. Finally, a monitoring plan is outlined 

that will verify the effectiveness of management measures in 

reducing overdraft. GROUNDWATER DEPLETION

455. U.S. Fish and Wildlife Service. 1989. National wetlands 

priority conservation plan. Washington, DC: U.S. 

Department of the Interior, U.S. Fish and Wildlife 

Service: 87 p.

Abstract: This document discusses wetland values and losses 

and provides evaluation criteria to be used in making wetland 

acquisition determinations. Guidance is also provided on the 

use of the National Wetland Priority and Conservation Plan 

and its relationship with other legislation, plans, policies, and 

programs. MULTIPLE THREATS

456. USDA Soil Conservation Service. 1977. On-farm program 

for salinity control: Final report of the Grand Valley 

salinity study. Grand Valley Project, Colorado. U.S. 

Department of Agriculture, Soil Conservation Service 

and Agricultural Research Service.

Abstract: The overall objectives of the Grand Valley Salinity Control studies are to determine (1) the salt loading from 

irrigated and related upland areas and (2) the opportunity 

for reducing salt loading through improvements on irrigated 

farmland and reducing erosion and sediment delivery from 

privately owned upland areas. WATER QUALITY

457. USDA Soil Conservation Service. 1979. USDA salinity 

report for the Uintah Basin unit: Colorado River Basin 

salinity control study: State of Utah. Salt Lake City, UT: 

U.S. Department of Agriculture, Soil Conservation Service, Forest Service, and Agricultural Research Service.

Abstract: The Uintah Basin Unit is predominantly an agricultural area. Irrigation was introduced in the Basin in 1905 

and has steadily increased since. There has also been a steady 

increase in saline land areas and in salt concentration in the 

river systems. One of the main objectives of this study is to 

determine the present contribution of salinity from irrigated 

cropland and related upland watersheds. WATER QUALITY

458. USDA Soil Conservation Service. 1981a. USDA salinity control and environmental assessment: Moapa 

Valley subevaluation unit, Nevada of the Virgin River 

Unit. Reno, NV: U.S. Department of Agriculture, Soil 

Conservation Service, Colorado River Basin Salinity 

Control Program.

Abstract: Moapa Valley Subevaluation Unit, a portion of 

Virgin River Unit, is a drainage to Colorado River. Moapa 

Valley Subevaluation Unit was identified as a problem area 

where irrigation and erosion are diffuse sources of salinity. 

During the study, alternative solutions were identified and 

estimates were made of effects of the plans to reduce salt 

loading to Colorado River. WATER QUALITY

459. USDA Soil Conservation Service. 1981b. USDA salinity 

control and environmental assessment: Virgin Valley 

subevaluation unit of the Virgin River Unit. Reno, NV: 

U.S. Department of Agriculture, Soil Conservation Service, Colorado River Basin Salinity Control Program.

Abstract: This report suggests that by reducing salt loading, 

the value of the Nation’s output of goods and services will be 

increased. In addition, this paper describes the Environmental 

Quality (EQ) and Economic Development (ED) objectives 

as follows: (1) The EQ objective is to improve water quality 

by reducing the sediment and salt load to the Colorado River 

and enhance fish and wildlife resources; (2) The ED objective is to increase the efficiency of agricultural production 

by improved irrigation efficiency and reduced downstream 

salinity damages. WATER QUALITY

460. USDI Bureau of Reclamation Engineering and Research 

Center. 1977. Final environmental statement INT FES 

77-15. Colorado River water quality improvement program (Vol. 1). U.S. Department of the Interior, Bureau 

of Reclamation; U.S. Department of Agriculture, Soil 

Conservation Service.

Abstract: This environmental impact statement is intended to 

provide a regional analysis of the basin-wide alternatives and 

cumulative effects of salinity control works, measures, and 

facilities. Las Vegas Wash and Crystal Geyser are addressed 

in a more detailed manner. WATER QUALITY

461. USDI Bureau of Reclamation. 1981. Saline water use and 

disposal opportunities: Colorado River water quality 

improvement program. Denver, CO: U.S. Department 

of the Interior, Bureau of Reclamation: 165 p.

Abstract: In order to meet the overall salinity control objective for the Colorado River Basin, approximately 2.8 million 

tons of salt per year will have to be removed from the river 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 75

system around the turn of the century. Environmental impacts 

of salinity control are discussed in two broad categories—

impacts associated with interception and/or collection of 

saline water and impacts associated with transport use and/

or disposal of saline water. WATER QUALITY

462. USDI Bureau of Reclamation. 1989. Lower Gunnison 

Basin unit, North Fork area: Preliminary findings report. 

Colorado River water quality improvement program. 

Denver, CO: U.S. Department of the Interior, Bureau 

of Reclamation.

Abstract: Of the 422,000 tons of salt contributed annually to 

the Colorado River system from the study area, about 274,000 

tons are attributed to on-farm sources, about 148,000 tons 

are attributed to off-farm sources, and less than 1 percent is 

attributed to saline flows from abandoned oil and gas wells. 

WATER QUALITY

463. Van Cleve, D.H.; Comrack, L.A.; Wier, H.A. 1988. Coyote 

Creek (San Diego County) management and restoration 

at Anza-Borrego Desert State Park. In: Abell, D.L., 

coord. Proceedings of the California riparian systems 

conference: Protection, management, and restoration 

for the 1990’s; 1988 September 22-24; Davis, CA. Gen. 

Tech. Rep. PSW-110. Berkeley, CA: U.S. Department of 

Agriculture, Forest Service, Pacific Southwest Forest 

and Range Experiment Station: 148-153.

Abstract: Despite its status as part of a State park, its relative inaccessibility, and the wilderness designation of much 

of the surrounding area, the Coyote Creek area suffers from 

numerous threats to its ecological health and its value as a 

refuge to humans and sensitive fauna. These threats include 

the impacts of humans on the natural, cultural and esthetic 

features and the effects of alien species on native flora and 

fauna. MULTIPLE THREATS

464. Vandersande, M.W.; Glenn, E.P.; Walworth, J.L. 2001. 

Tolerance of five riparian plants from the lower Colorado River to salinity, drought and inundation. Journal 

of Arid Environments. 49: 147-159.

Abstract: The purpose of this controlled greenhouse study 

was to determine the interaction of salt and water stress on the 

survival, salt tolerance, water-use characteristics, and growth 

rates of plant species currently found along the Colorado 

River. The study also aimed to determine the tolerance of 

the same species to long-term inundation of the root zone. 

MULTIPLE THREATS

465. Walters, C. 1997. Challenges in adaptive management of 

riparian and coastal ecosystems. Conservation Ecology. 

1(2):1. Online: http://www.consecol.org/vol1/iss2/art1/.

Abstract: This paper discusses four reasons for low success 

rates in implementing policies of adaptive management. First, 

modeling for adaptive-management planning has often been 

supplanted by ongoing modeling exercises. Second, effective 

experiments in adaptive management often have been seen 

as excessively expensive and/or ecologically risky, compared 

to best use baseline options. Third, there is often strong 

opposition to experimental policies by people protecting 

various self-interests in management bureaucracies. Fourth, 

there are some very deep value conflicts within the community of ecological and environmental management interests. 

MULTIPLE THREATS

466. Warner, R.E. 1984. Structural, floristic and condition 

inventory of Central Valley riparian systems. In: Warner, 

R.E.; Hendrix, K.M., eds. California riparian systems: 

Ecology, conservation, and productive management. 

Berkeley: University of California Press: 356-374.

Abstract: This paper reports a ground-based inventory of 

51 riparian sites. Morphological structures, floristics, plant 

diversity and site condition were quantified using an inventory methodology designed for that purpose. Condition 

trends are assessed, and human-use impacts are discussed. 

MULTIPLE THREATS

467. Welsch, D.J. 1991. Riparian forest buffers: Function 

and design for protection and enhancement of water 

resources. NA-PR-07-91. Radnor, PA: U.S. Department of Agriculture, Forest Service, Forest Resources 

Management, Northeastern Area, State and Private 

Forestry. 20 p.

Abstract: This document provides a description of streamside 

forest ecosystems and the adverse affects of their removal on 

water resources. Further it describes how streamside forests 

are beneficial to water quality. It also gives an example for 

the establishment of effective forest buffers based on current 

research findings. WATER QUALITY

468. Wesche, T.A. 1985. Stream channel modifications and 

reclamation structures to enhance fish habitat. In: Gore, 

J.A., ed. The restoration of rivers and streams. Boston: 

Butterworth Publishers: 103-163.

Abstract: This chapter discusses the basic instream components of fish habitat, the impacts of various channel 

modification activities on habitat diversity, as well as channel 

restoration procedures and structures to enhance fish habitat 

from a planning aspect and from a design and installation 

approach. MULTIPLE THREATS

469. Wheeler, G.P.; Francher, J.M. 1984. San Diego County 

riparian systems: Current threats and statuary protection efforts. In: Warner, R.E.; Hendrix, K.M., eds. 

California riparian systems: Ecology, conservation, 

and productive management. Berkeley: University of 

California Press: 838-843.

Abstract: The effectiveness of present laws in conserving 

San Diego County riparian systems is examined. Agencies 

are more effective when several laws apply, when credible 

statuary authority and enforcement exists, and when public 
76 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

support is generated. Population pressures and development 

pose the greatest threats to San Diego County riparian systems. URBANIZATION

470. Whitney, J.C. 1996. The Middle Rio Grande: Its ecology 

and management. In: Shaw, D.W.; Finch, D.M., tech. 

coords. Desired future conditions for southwestern 

riparian ecosystems: Bringing interests and concerns 

together. Gen. Tech. Rep. RM-272. Fort Collins, CO: 

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

Mountain Forest and Range Experiment Station: 4-21.

Abstract: The Rio Grande is regulated for water supply 

(primarily irrigation) and flood control. The effects of this 

interaction have contributed to the character of the riparian 

ecosystem in its expression. Over 40% of New Mexico’s 

population lives within the Middle Rio Grande reach. This 

paper discusses the climate, geology, hydrology, subsequent 

river morphology, and anthropogenic factors that contribute 

to the past and current expressions of the riparian habitat associated with the Middle Rio Grande. MULTIPLE THREATS

471. Williams, C.D. 1984. The decline of Ash Meadows, a 

unique desert ecosystem. In: Warner, R.E.; Hendrix, 

K.M., eds. California riparian systems: Ecology, 

conservation, and productive management. Berkeley: 

University of California Press: 716-719.

Abstract: Ash Meadows is a unique hydric ecosystem of 

the Amargosa desert. The approximately 162 km2

 area is 

dominated by over 30 springs and seeps that support a wide 

variety of plant and animals life, including nearly 30 endemics. 

Ash Meadows was apparently heavily used by several Indian 

cultures. Since the late 1960s, the area has been subject to 

a variety of agricultural, industrial, residential and mineral 

development schemes, the most recent of which threatens to 

cause the demise of the ecosystem. MULTIPLE THREATS

472. Williams, D.F.; Kilburn, K.S. 1984. Sensitive, threatened, 

and endangered mammals of riparian and other wetland 

communities in California. In: Warner, R.E.; Hendrix, K.M., eds. California riparian systems: Ecology, 

conservation, and productive management. Berkeley: 

University of California Press: 950-956.

Abstract: Studies of the distribution, habitat requirements, 

and population status of species and subspecies of mammals in California were conducted in order to identify taxa 

threatened with extinction. It was found that destruction of 

riparian and other wetland communities is the principle factors jeopardizing 21 taxa. MULTIPLE THREATS

473. Williams, J.E.; Kobetich, G.C.; Benz, C.T. 1984. Management aspects of relict populations inhabiting the 

Amargosa Canyon ecosystem. In: Warner, R.E.; Hendrix, K.M., eds. California riparian systems: Ecology, 

conservation, and productive management. Berkeley: 

University of California Press: 706-715.

Abstract: Amargosa Canyon is one of three areas within the 

264-km Amargosa River drainage of Nevada and California 

that contains permanently flowing water. The extensive riparian community and associated habitats of Amargosa Canyon 

contain a large number of relict populations. Although the 

USDI BLM has designated Amargosa Canyon a roadless 

area, the ecosystem is threatened by illegal off-road vehicle 

use, exotic species, upstream urbanization, and mining of 

groundwater aquifers. MULTIPLE THREATS

474. Winter, P.L. 1993. Positives and negatives of recreation in 

riparian areas. In: Tellman, B.; Cortner, H.J.; Wallace, 

M.G.; DeBano, L.F.; Hamre, R.H., tech. coords. Riparian management: Common threads and shared interests. 

A western regional conference on river management 

strategies; 1993 Feb 4-6; Albuquerque, NM. Gen. Tech. 

Rep. RM-226. Fort Collins, CO: U.S. Department of 

Agriculture Forest Service, Rocky Mountain Forest and 

Range Experiment Station: 155-158.

Abstract: This paper summarizes work conducted by the 

Pacific Southwest Research Station’s Wildland Recreation 

and Urban Culture project conducted from 1987 to 1993. This 

project has conducted many studies in riparian day-use areas 

because these areas have been found to be a reliable point of 

contact for recreationists. RECREATION

475. Woessner, W.W.; Mifflin, M.D.; French, R.H.; Elzeftawy, 

A.; Zimmerman, D.E. 1984. Salinity balance of the 

Lower Virgin River basin, Nevada and Arizona. In: 

French, R.H., ed. Salinity in watercourses and reservoirs: 

Proceedings of the 1983 international symposium on 

state-of-the-art control of salinity; 1984 July 13-15;Salt 

Lake City UT. Boston MA: Butterworth Publishers: 

145-156.

Abstract: This 12-month study developed additional hydrologic data for the development of salinity budgets in the 

Lower Virgin River Valley, Nevada and Arizona, a tributary 

of the Colorado River. Results indicate a complex hydrologic 

system with concentration, storage, and transport of salt 

occurring in the study area. Water and salt budget analysis 

indicate a 36% net loss of water and a 34% net loss in salt for 

a 61-km reach of river. The majority of water loss is attributed 

to saltcedar consumptive use. Salt concentrations associated with saltcedar consumptive use exceeded consumptive 

concentration of salt by agriculture and direct evaporation 

by 2.6 times. Data indicate that saltcedar areas play a major 

role in salt accumulation and storage. INVASIVE SPECIES, 

WATER QUALITY

476. Wohl, E.; Cooper, D.; Poff, N.L.; Rahel, F.; Staley, D.; 

Winters, D. 2007. Assessment of stream ecosystems 

function and sensitivity in the Bighorn National Forest, 

Wyoming. Environmental Management. 40: 284-302.

Abstract: This paper presents a hierarchical analysis of 

stream ecosystem distribution and sensitivity to natural and 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012 77

anthropogenic disturbances for the Bighorn National Forest, 

WY. The assessment presented here highlights the regional 

uniqueness and importance of watersheds within the forest, 

which contain predominately high-gradient stream dominated by snowmelt and mixed snowmelt and rainfall runoff. 

CLIMATE CHANGE

477. Wozniak, F.E. 1996. Human impacts on riparian ecosystems of the Middle Rio Grande Valley during historic 

times. In: Shaw, D.W.; Finch, D.M., tech. coords. Desired 

future conditions for southwestern riparian ecosystems: 

Bringing interests and concerns together. Gen. Tech. 

Rep. RM-272. Fort Collins, CO: U.S. Department of 

Agriculture, Forest Service, Rocky Mountain Forest 

and Range Experiment Station: 33-43

Abstract: The development of irrigation agriculture in 

historic times has profoundly impacted riparian ecosystems 

in the Middle Rio Grande Valley of New Mexico. A vital 

relationship existed between water resources and settlement 

in the semi-arid Southwest since prehistoric times. Levels 

of technology have influenced human generated changes in 

the riparian ecosystems of the Middle Rio Grande Valley. 

AGRICULTURE

478. Wright, H.E., Jr. 1981. The role of fire in land/water 

interactions. In: Mooney, H.A.; Bonnicksen, T.M.; 

Christenson, N.L.; Lotan, J.E.; Reiners, W.A., tech. 

coords. Fire regimes and ecosystem properties: Proceedings of the conference; 1978 December 11-15; Honolulu 

HI. Gen. Tech. Rep. WO-26. Washington, DC: U.S. 

Department of Agriculture, Forest Service: 421-444.

Abstract: Forest fires cause a temporary increase in runoff to streams and lakes. Mass transport of nutrients and 

cations also increase. The charcoal and pollen stratigraphy 

of annually laminated lake sediments provides a record of 

past fire frequency. Lake-sediments studies also document 

forest history over thousands of years showing the shift from 

fire-adapted forest to resistant forest, or the reverse. FIRE

479. Yeager, T.D. 1996. Critical groundwater hydroperiods for 

maintaining riparian plant species (Thesis). Laramie, 

WY: University of Wyoming: 52 p.

Abstract: This study specifically reports on how three important riparian plant species responded to variable water table 

conditions. The three herbaceous riparian species chosen for 

this experiment were Nebraska sedge, tufted hairgrass, and 

Kentucky bluegrass. DROUGHT

480. Yong, W.; Finch, D.M. 1996. Landbird species composition and relative abundance during migration along 

the Middle Rio Grande. In: Shaw, D.W.; Finch, D.M., 

tech. coords. Desired future conditions for southwestern 

riparian ecosystems: Bringing interests and concerns 

together. Gen. Tech. Rep. RM-272. Fort Collins, CO: 

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

Mountain Forest and Range Experiment Station: 77-92.

Abstract: This paper reports species composition and relative abundance of stopover migrants during spring and fall 

migration along the middle Rio Grande in 1994. Comparisons 

of relative abundance from previous studies demonstrated 

that population of many species have remained relatively 

stable over approximately 6- and 12-year periods, while 

some species have become more common or rare. Research 

recommendations focusing on bird use of stopover habitats 

during migration along the Rio Grande are provided. MULTIPLE THREATS
78 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-269. 2012

Agriculture: 15, 68, 114, 117, 136, 218, 322, 381, 414, 477

Climate Change: 1, 24, 94, 97, 140, 171, 211, 227, 311, 

341, 363, 370, 371, 387, 391

Dam Construction: 58, 59, 79, 90, 157, 177, 183, 223, 

226, 315, 342, 369, 370

Drought: 2, 109, 172, 260, 354, 420, 424, 451, 479

Fire: 24, 43, 86, 127,144, 217, 331, 356, 380, 402, 403, 

417, 478

Floods: 80, 100, 118, 158, 164, 171, 193, 424

Flow Regulation: 29-31, 33, 38,118,128,133, 182

Forest Harvesting: 40, 45, 82, 213, 266, 276, 348, 352, 

356, 401, 413, 417, 453

Grazing: 1, 6, 9, 17, 34-36, 46, 51, 73-75, 83, 88, 93, 

98, 99, 103-108, 110, 120-123, 126, 130, 131, 138,145, 

147-151, 161, 163, 174-176, 180, 184, 187, 189, 201, 234, 

236, 237, 239, 240, 242, 248, 250, 252, 257-259, 263, 

267, 269, 274, 275, 281, 282, 284, 287, 292, 295, 304, 

308, 313, 321, 324, 335-339, 34, 351, 359, 360, 362, 364, 

365, 374, 375, 379, 384, 388, 389, 390, 393, 395-397, 399, 

405, 418, 428, 431, 437, 440, 442, 449, 453 

Groundwater Depletion: 10, 48, 128, 172, 182, 200, 

202, 203, 260, 272, 386, 420-423, 454

Insects & Disease: 184, 314, 368

Invasive Species: 3, 5, 12, 14, 19, 26, 30, 32, 56, 66, 

87, 95, 100, 101, 109, 111, 137, 143, 146, 153, 164, 199, 

203, 204, 206, 207, 210, 225, 243, 247, 251, 268, 270, 

272, 273, 283, 288, 289, 296, 299, 301, 303, 325-327, 

355, 373, 392, 403, 404, 412, 426, 430, 448

Mining: 18, 152, 192, 255, 256, 286, 353

Multiple Threats: 7, 8, 11, 13, 16, 20-23, 28, 37, 39, 41, 

42, 44, 47, 49, 52, 55, 57, 61-65, 67, 69, 71, 76-78, 81, 84, 

85, 89, 91,92, 96, 116, 119, 122, 124, 125, 129, 134, 135, 

139, 142, 154-156, 159,160, 166-168, 170, 173, 178, 181, 

185, 186, 188,191, 195-198, 205, 208, 209, 214-216, 219, 

221, 222, 224, 229-231, 232, 233, 235, 238, 241, 244-

246, 249, 253, 262, 262, 264, 277, 278, 280, 288, 290, 

292, 293, 294, 298, 300, 302, 305, 307, 309, 310, 312, 

314, 316-320, 323, 329, 330, 332-336, 349, 357, 358, 361, 

366, 367, 372, 376-378, 383, 394, 398, 400, 406-409, 

411, 415, 416, 419, 420, 425, 429, 432-436, 438, 439, 441, 

443-445, 447, 450, 455, 463-466, 468, 470-473, 476, 480 

Recreation: 4, 5, 27, 54, 141, 162, 220, 254, 271, 279, 

285, 382, 474

Roads: 265, 350

Urbanization: 68, 165, 385, 469

Water Diversion: 53, 70,194, 261

Water Quality: 1, 50, 60, 72, 99, 102, 112, 113, 115, 

169, 179, 190, 212, 218, 228, 297, 306, 328, 340, 343, 

347, 380, 446, 452, 456-462, 467

Index of Reference Numbers

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