Regional Riparian Research and a Multi-University Approach to the Special Problem of Livestock Grazing in the Rocky Mountains and Great Plains^[1]

David W. Crumpacker^[2]

Abstract.—A selected survey of Rocky Mountain/Great Plains riparian research with emphasis on livestock grazing impacts and management is presented. A multiuniversity plan for studying interactions between livestock grazing and riparian resources in the region is presented. The power of an integrated, regionwide approach is compared with that of one involving the conduct of numerous independent, site-specific studies. An analogy is made to California, considering the State as a region. The need for support of long-term riparian research by traditional academic funding sources is also stressed.

Introduction

This report is meant to serve three purposes: 1) provide a Rocky Mountain and Great Plains regional perspective on riparian research to complement similar reports at this conference on the American Southwest and Intermountain Region; 2) discuss relationships between livestock grazing and riparian resources; and 3) describe a regional, multi-university approach to riparian research.

Status and Value of Western U.S. Riparian Ecosystems

Recent estimates indicate that 70–90% of the natural riparian ecosystems in the United States have been lost to human activities (US Council on Environmental Quality 1978; Warner 1979a; Swift and Barclay^[3] ). Losses have been estimated at 98.5% in the Sacramento Valley of California (Smith 1980) and 95% or more in Arizona (Warner 1979b). In the Rocky Mountain/Great Plains region Johnson and Carothers (1981) believe that 90–95% of the cottonwood/willow riparian ecosystems of the plains and lower foothills have been lost. Beidleman (1978) has stated that this is unquestionably the most productive and highly diversified ecosystem type in the Rocky Mountains and Great Plains. Perhaps 80% of the publicly and privately owned riparian areas that still exist in the United States are in an unsatisfactory condition or are dominated by human activities (Almand and Krohn 1978; Warner 1979b).

Western U.S. riparian ecosystems contain disproportionately great concentrations of wildlife species and populations compared to adjacent uplands. This has been well documented in the American Southwest (Davis 1977; Johnson 1971; Johnson and Carothers 1975; Johnson, Haight and Simpson 1977; Stevens etal . 1977) and the Pacific Northwest (see discussion and references cited in Thomas, Maser and Rodiek 1979). The situation is similar in the Rocky Mountains

[1] Paper presented at the California Riparian Systems Conference. [University of California, Davis, September 17–19, 1981].

[2] David W. Crumpacker is Professor of Environmental, Population and Organismic Biology, University of Colorado, Boulder, Colo. He is also President-Elect of the Eisenhower Consortium for Western Environmental Forestry Research which has its main office at 240 W. Prospect St., Fort Collins, Colo.

[3] Swift, B.L. and J.S. Barclay. 1980. Status of riparian ecosystems in the United States. Unpublished manuscript. 29 p. USDI Fish and Wildlife Service, Kearneysville, W. Va. [Prepared for presentation at the 1980 American Water Resources Association National Conference, Minneapolis, Minn.] Cited in Johnson, R. Roy and Steven W. Carothers. 1981. Southwestern riparian habitats and recreation: interrelationships and impacts in the Rocky Mountain Region. Eisenhower Consortium Bulletin. [In press]. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, Colo.

and Great Plains. Beidleman (1978) estimated very conservatively that the cottonwood/willow ecosystem type contains at least 40% of the vertebrate species found in that region. The South Platte River Valley of northeastern Colorado in Weld and Morgan Counties has 151 vertebrate species of which 147 (97%) make at least seasonal use of the riparian and associated aquatic zones (Fitzgerald 1978). The mixed cottonwood/willow community type has the most species of birds and mammals, whereas the openpark, open-cottonwood, and aquatic types have the most reptilian and amphibian species (Fitzgerald 1978). The native trees and shrubs in the moist hardwood draws of northern plains grasslands comprise less than 1% of the regional ecosystems, but are believed to provide valuable, and possibly critical, wildlife habitat (Boldt, Uresk, and Severson 1978).

Livestock Grazing and Riparian Resources

Impacts

Livestock grazing is the most pervasive land use in the western United States. Eighty-three percent of the 11 conterminous western states is in forest and range and much of this is grazed by livestock. Nationwide, it has been estimated that 70% of the forests and rangelands are grazed (Platts 1979). Cattle derive great value from western riparian ecosystems. They strongly prefer them for a number of reasons (Ames 1977), the most important of which is access to water. This preference increases as summer progresses and the adjacent upland vegetation becomes depleted or desiccated (Dahlem 1979; Martin 1979).

The major direct impacts of livestock grazing are on vegetation and soils. This can cause severe indirect effects on wildlife. Grazing for only a few days or weeks has sometimes been observed to cause serious damage to woody regeneration (Ames 1977; Duff 1979). Extensive grazing can lead to virtually no reproduction of trees and a decadent riparian forest. If too much protective ground cover is removed, the soil becomes compacted, infiltration of precipitation decreases, and erosion of topsoil into the aquatic zone occurs (Moore etal . 1979; Thomas, Maser and Rodiek 1979; Platts 1979). Major detrimental effects to trout habitats and populations can then occur (Behnke and Raleigh 1978). Excessive use of the riparian zone by livestock also lowers its commercial grazing value. Soil compaction by trampling tends to favor shallow-rooted, herbaceous perennials or tap-rooted perennial shrubs in place of fibrous-rooted plants which are usually more palatable, nutritious and dependable on a yearround basis (Platts 1979).

Recovery under Livestock Exclosure or Withdrawal

Numerous observations on recovery of riparian and aquatic ecosystems following complete exclusion of livestock have been reported in recent years. Many of the observations involved unreplicated comparisons and none included statistical analyses of the results. Nevertheless, the combined weight of this evidence suggests that there is considerable resilience in western U.S. riparian and aquatic systems. Platts (1979) and Keller, Anderson and Tappel (1979) reviewed a number of these studies that focused on streams and fisheries. Moderate to large percentage improvements were observed in riparian vegetation, streambank stability, channel morphology, substrate, water temperature, and trout number and biomass. A period of up to five years may be needed for reasonable recovery of an aquatic system, following removal of livestock (Behnke and Raleigh 1978; Moore etal . 1979; Skovlin^[4] ).

Some information is also available on the response of riparian trees and shrubs following livestock exclosure. Glinski (1977) observed large increases in cottonwood regeneration in an area of relatively abundant water and long growing season in southeastern Arizona, following eight years of exclosure. Davis (1977) has observed that young cottonwood, alder, and sycamore can grow 3–4.6 m. (10–15 ft.) in a few years in the American Southwest if protected from grazing. Crouch (1978) noted a doubling of woody understory in a cottonwood/willow community along the South Platte River in northeast Colorado, after seven years of exclosure. No further increases were observed during 18 additional years. Although the number of cottonwoods decreased in both the grazed and ungrazed areas that Crouch studied, the decline was 38% less for the ungrazed area. (The decline in the ungrazed area was attributed to other factors, one of the most important being managed stream flows which are detrimental to cottonwood germination and establishment.) A literature survey by Skovlin^[4] led him to suggest that five to eight years may be required for acceptable recovery of riparian shrubs in most areas. A high-altitude willow community at 2650 m. in the North Park region of north central Colorado (46 frost-free days) was observed by Knopf and Cannon (1981) to recover at a slow rate following removal from chronic, heavy grazing pressure. They noted that their results lend quantitative support to Myers' estimate (1981) that: a) 10 to 12 years may be insufficient time for a southwestern Montana willow community to recover from prolonged, excessive grazing; and b) it is more difficult to improve a damaged riparian ecosystem by removing it from grazing than it is to maintain a good one while grazing it. These various observations suggest that riparian ecosystems do not undergo

[4] Skovlin. Impacts of grazing on wetlands and riparian habitat—the state of our knowledge. Unpublished draft manuscript, presented at National Academy of Sciences/National Research Council workshop: Impacts of grazing intensity and specialized grazing systems on use and value of rangelands. [March 16–17, 1981, El Paso, Tex.].

general recovery from overgrazing as rapidly as their aquatic counterparts, particularly in regions with short growing seasons.

Grazing Management Options

A number of grazing management options have been suggested for riparian/aquatic systems by wildlife and fishery researchers and managers (e.g. Behnke and Raleigh 1978; Benson 1979; Moore etal . 1979; Skovlin;^[4] Storch 1979). These include alternatives such as the following: complete exclosure from grazing; management as a separate pasture in a grazing system; tailoring the management to specific flora, conditions, etc.; location of watering, salt, and supplement sites away from the riparian zone; intensive herding; reduction of stocking rates; seasonal deferments and/or yearly rests; specially designed grazing systems with six or more pastures instead of the standard two to five; changing the age and class of livestock; initial exclosures of five or more years to allow recovery of degraded riparian vegetation. There have been few suggestions from range scientists concerning riparian management under rangeland conditions. Their suggestions are also needed in order to achieve satisfactory solutions.

There has been considerable interest recently concerning the effectiveness of rest-rotation grazing systems in permitting adequate recovery and maintenance of riparian and aquatic ecosystems. There are many possible types of these grazing systems and they may include seasonal deferments in addition to the year-long rests for which they are named. Rest-rotation grazing was originally developed for upland ranges in ponderosa pine ecosystems (Stoddart etal . 1975) and is now commonly recommended by the Bureau of Land Management (BLM) in other grazing environments (Lea 1979).

Since rest-rotation systems were designed primarily for the maintenance of herbaceous range plants rather than woody riparian vegetation (Thomas, Maser and Rodiek 1979), it is certainly desirable to question their value for use in riparian recovery and maintenance. Wildlife and fishery biologists have been concerned that too much dependence on rest-rotatation systems will result in continued deterioration of riparian and aquatic systems (Armour 1979; Behnke and Raleigh 1978; Severson and Boldt 1978; Platts 1979). Although general observations and experience suggest this may be so, strong supporting evidence has not yet been produced. There is an obvious need for experimentally reliable tests of the effects of rest- and deferred-rotation grazing systems on riparian and aquatic ecosystems (Armour 1979; Platts 1979; Raleigh 1979a,b).

Furthermore, most previous observations have compared the effects of heavy, uncontrolled or unmanaged grazing to no grazing, whereas the more interesting comparisons involving light or moderate grazing have not been reported (Lea 1979; Skovlin^[4] ).

Current Research Initiatives

Several new investigations involving livestock-riparian interactions have been briefly described by Moore et al . (1979). Skovlin and Meehan are conducting a five-year study in the Blue Mountains of northeast Oregon. They are evaluating the effects of livestock grazing management strategies and effects of big game on soil, water quality and quantity, fish populations, benthic fauna, and productivity and utilization of herbaceous and woody vegetation.

According to Duff (as reported by Moore etal . 1979), effects of a three-pasture, restrotation system in southwest Utah will be monitored by exclosures in conjunction with BLM's Hot Desert Environmental Statement. Data will be obtained on recovery of vegetation and on fisheries and water quality in selected stream reaches.

According to Platts (as reported by Moore etal . ibid .) and Janes^[5] , a large 10-year study involving private (Saval Ranch) and Federal (BLM and USDA Forest Service (FS)) lands in Nevada is now underway. One aspect of this "Saval Ranch Study" will be to evaluate upland, riparian and aquatic responses to a new experimental grazing system which involves the use of a number of pasture units. Exclosures will also be maintained as controls. The Nevada Fish and Game Department will assist by conducting wildlife surveys and the USDA Science and Education Administration will perform hydrologic studies and inventories of soils and vegetation.

Various new Federal riparian research initiatives are either planned or underway in the Rocky Mountain/Great Plains region. Some of these will be described in order to indicate the current direction of riparian research.

USDI Fish and Wildlife Service

The Denver Wildlife Research Center of the USDI Fish and Wildlife Service (FWS) has recently initiated several studies of riparian ecosystems (Knopf^[6] ). Previous wildlife reports have indicated that higher elevation riparian systems have fewer species (Burkhard 1978; Schrupp 1978), as well as fewer stenotopic species (Burkhard 1978; Salt 1957), than lower riparian systems in the Rocky Mountains/Great Plains region. However, these observations have not been quantified within the different vegetation-types occurring along an altitudinal cline. Therefore, one of the projects will determine the significance of riparian vegetation to avian and mammalian communities on an altitudinal gradient. Faunal densities and vegetative parameters will be estimated in both

[5] Janes, Eric A. 1981. Personal communication. USDI Bureau of Land Management, Denver Service Center, Denver, Colo.

[6] Knopf, Fritz L. Personal communication. USDI Fish and Wildlife Service, Denver Wildlife Research Center, Fort Collins, Colo.

riparian and adjacent upland communities in north central and northeast Colorado as follows: willow vs. Engelmann spruce/subalpine fir at 2900 m.; willow and two stands of narrowleaf cottonwood/willow vs. ponderosa pine at 2100–2560 m.; open narrowleaf cottonwood/willow vs. mountain mahogany shrub at 2000–2200 m.; willow and plains cottonwood/willow vs. sagebrush steppe at 2650 and 1200 m. respectively; willow vs. aspen at 2600 m. Thus the significance of riparian vegetation to birds and mammals will be determined at each location as well as any changes in significance with altitude. Each of the study sites has been protected from livestock grazing for at least three years.

Research is in progress at the 2650 m. willow site mentioned above (Arapahoe National Wildlife Refuge) to monitor the effects of a three-year, rest-rotation grazing system on vegetation and avifauna.

The FWS in conjunction with the Colorado Division of Wildlife (Knopf^[6] ) also plans to assess vegetative and vertebrate responses to cattle grazing in a lowland, broadleaf cottonwood/willow community on the northeast plains of Colorado. The study site has been protected from livestock grazing for 30 years. This interesting experiment is essentially the reverse of those in which responses are observed in overgrazed riparian zones following removal of livestock. The effects of light to moderate grazing on a long-ungrazed riparian ecosystem will be determined. Interest will also be focused on identifying the most useful indicator species for the effects of grazing practices.

USDA Forest Service

The Rocky Mountain Forest and Range Experiment Station of the FS has a continuing interest in riparian studies in two parts of its region of responsibility, A southwestern section of the Station, with headquarters at Tempe, Arizona, is developing a comprehensive program that includes, or will include, studies on classification of plant communities, methods of artificial regeneration, effects of livestock on regeneration and maintenance of riparian systems, livestock behavior, and mammalian associations (Martin 1979; Smith^[7] ). A northern plains section of the Station, with headquarters at Rapid City, South Dakota, is conducting research on multiple-use management of woody riparian draws (e.g., see Boldt, Uresk and Severson 1978).

The Station has proposed in its 1980 Forest and Rangeland Renewable Resources Planning Act (RPA) program plan to expand both the southwestern and northern plains studies and to initiate new projects over the next 10 years as follows (Smith^[7] ; location of project headquarters in parentheses): management of riparian and associated aquatic systems within rangeland environments (Laramie, Wyoming); marketing and silviculture of bottomland hardwoods, primarily cottonwoods (Lincoln, Nebraska); integrated management of riparian systems in forest environments (Fort Collins, Colorado). This last project will complement the existing effort at Tempe which deals with integrated management of riparian systems in rangeland environments. "Integrated management" refers in this context to managing riparian ecosystems without fencing the riparian zone or including it in a separate pasture of a grazing system.

USDI Bureau of Land Management

A very interesting, worthwhile effort is being made by the Rock Springs, Wyoming District of the BLM to provide information on recovery of overgrazed riparian/aquatic ecosystems by constructing and monitoring approximately 60 exclosures in southwest Wyoming (Smith^[8] ). Some of the exclosures will be maintained as controls while others will be used as experimental grazing units. The program was begun in 1976. It includes 20 exclosures, each 8 ha. (20 ac.) in size, and nine special grazing management units that will be located in the Big Sandy drainage. Sites will range from the lower sagebrush steppe area in the cold desert, which presently contains only sparse remnants of riparian vegetation, to willow communities in the foothills and aspen/willow communities in montane regions.

The Big Sandy system of exclosures is about 80% completed. Fenced plots already installed in the foothills zone of the Bear River drainage include five riparian/aquatic exclosures and eight riparian/aquatic special pasture units. Other exclosures have been set up in the Green River basin in the vicinity of Big Piney, Wyoming. Fenced plots have been constructd in the region south of Rock Springs, Wyoming to determine the feasibility of using beaver to restore the riparian water in a gulley-cut, eroded situation.

The immediate purpose of BLM's efforts in the Rock Springs District is to provide demonstrations of riparian/aquatic recovery. However, the potential clearly exists to utilize these exclosure systems for cooperative scientific investigations on a diverse group of riparian ecosystems and on the relation of riparian/aquatic resources to livestock grazing.

A Proposed Multi-University Approach

The tremendous concentration of natural diversity in western riparian ecosystems, which are rapidly shrinking in both quantity and quality, calls for an extensive program of research and development directed towards im-

[7] Smith, Dixie R. Personal communication. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, Colo.

[8] Smith, Bruce H. Personal communication. USDI Bureau of Land Management, Rock Springs District, Rock Springs, Wyo.

proved multiple use management. Since livestock grazing is the most pervasive land use in much of the western U.S. and is acknowledged to have major impacts on riparian ecosystems, research on the relationship of livestock grazing management to riparian resources appears to have the greatest potential for maintaining and enhancing these resources. This situation led the Eisenhower Consortium for Western Environmental Forestry Research to develop a regional research plan for the states of Wyoming, Colorado, New Mexico, and Arizona (Crumpacker etal . 1981^[9] ).

The Eisenhower Consortium Plan

Study Design

The Eisenhower Consortium plan involves a long-term study to provide comparative information on the response of previously overgrazed riparian ecosystems to three kinds of experimental treatments:

1. a new rotation grazing system that includes one or more seasonal deferments and/or a year-long rest (e.g., a 3-pasture rotation with early- and late-season deferments or a 4-pasture rotation that also includes a year-long rest);

2. no grazing (achieved by fenced exclosures);

3. no grazing for several years (using exclosures) followed by the rotation grazing system used for (1), above.

The grazing systems described in treatment 1 are examples of systems which the BLM is actually recommending in their range improvement programs with the primary intention of improving upland ranges.^[10] The treatments would be implemented by commercial operators on public grazing lands managed by one or more Federal or state agencies. A main purpose of the study would be to monitor the riparian responses in the setting of a commercial cattle operation.

The investigation should last 9–12 years, and preferably longer, in view of the evidence cited earlier on recovery of woody vegetation following exclosure, the expectation of even longer recovery periods associated with treatment 1, and the need to sample a representative set of climatic conditions. The riparian zone would not be treated separately, e.g., by separate fencing or designation as a separate pasture in the grazing system. Instead, each experimental plot would include portions of the riparian zone as well as the adjacent upland and aquatic zones. All plots would be included within one pasture of the grazing system.

A four-pasture, four-year, rest-rotation system of the following type appears preferable for experimental study in the Eisenhower Consortium region because it includes several components which are basic to many grazing systems:

1. early-season deferment (graze after flowering of upland range grasses)—protects young riparian vegetation during germination, sprouting, and early growth, and during maximum susceptibility of soils and stream banks to compaction and erosion;
2. early- and mid-season deferment (graze after seed ripening of upland range grasses)—extends the protection of 1, above, further into the riparian growing season;
3. mid- and late-season deferment (graze in spring until flowering of upland range grasses)—protects young riparian vegetation during warmest part of the year when less succulent upland vegetation is available and cattle tend to congregate more often in the riparian zone;
4. no grazing throughout the year.

The actual chronological sequence for a particular pasture might be 1, 3, 2, 4. A threepasture, three-year, deferred-rotation could be obtained by the sequence 1, 3, 2, but would presumably be more likely to require a longer time for riparian improvement and be less likely to permit riparian recovery.

Half of the experimental plots would be closed by fencing to provide the compariaon of riparian, aquatic, and upland responses to grazing vs. no grazing (treatment 1 vs. 2). Additional exclosed plots could be maintained until a decision was made to open them to grazing (treatment 3), after which a second comparison would be available (treatment 3 vs. 2). A more efficient means of obtaining treatment 3 might be to begin the experiment with double-sized closed plots (recording data from one-half of each closed plot) and then to open one-half of each such plot to grazing in order to create treatment 3.

Data Collection and Analysis

Data on basic soil, vegetative and aquatic parameters would be collected from the riparian, upland, and aquatic zones in each plot, as applicable. Several possible experimental designs could be used to provide the desired group of replicated plots. For example, a relatively large number of relatively small plots could be located at approximately equal distances along a drainage, half of them designated at random for fencing to provide exclosures. If there is extreme spatial heterogeneity of riparian vegetation, one alternative would be to locate a few

[9] Crumpacker, David W., R. Roy Johnson, James O. Klemmedson, Paul A. Rechard, Thomas A. Wesche, and Robert G. Woodmansee. 1981. Effects of livestock grazing on resource values of western riparian ecosystems. Research plan prepared for the Eisenhower Consortium for Western Environmental Forestry Research, 240 W. Prospect, Fort Collins, Colo.

[10] e.g., see USDI, Bureau of Land Management, Draft Environmental Impact Statement of Grazing Management in the Missouri Breaks of Montana.

relatively large, homogeneous main plots at strategic positions to include riparian vegetation, half of them open and half closed. A number of small subplots within each main plot could then be randomly assigned as replicates. In either case, a certain distance would have to be maintained between plots in order to minimize upstream effects on neighboring downstream plots. This would be a more serious source of bias in the aquatic than in the riparian and upland parts of each plot.

Since all experimental plots would be assigned to one pasture in a four-pasture, restrotation grazing system, the open plots would be exposed to each of the four components of the system described above only once every four years. Hence, comparisons such as the difference between grazed and ungrazed treatments when the grazing involved an early-season deferment vs. when it involved a mid- and late-season deferment would be confounded with years. However, this still appears to be one of the most satisfactory ways to obtain the desired information within the practical limitations of a commercial ranching operation.

The longer the period of study, the more opportunity there would be to overcome the confounding effects of individual years on comparisons involving different components of the rotation grazing system. The comparisons of most interest, viz. those of grazing vs. no grazing (1 vs. 2, see previous page) and grazing following an initial period of rest vs. no grazing (3 vs. 2, see previous page) fortheentiresystem can be made once every four years at the completion of each full cycle of the rotation. A 12-year experiment would provide three such comparisons.

Tradeoffs

The sacrifice of an ideal experimental situation in which riparian and other responses to each grazing system component are studied each year must be weighed against the advantages of the Eisenhower Consortium scheme which utilizes public lands, public land managers, and commercial ranching operations. The cost of leasing fully experimental lands, combined with the considerably larger size of an ideal experiment, would be much greater. It might also be difficult to find a reasonably homogeneous site for such a large experiment. In addition, scientific results obtained under realistic conditions of operation are much more likely to be accepted by the livestock industry.

Another alternative approach would be to study individual grazing system components, such as early-season deferment, in completely separate experiments. However, the cumulative cost of a full set of such experiments might be as high as the holistic Consortium approach and the need would still exist to test certain combinations of the most effective components in a commercially applicable grazing system.

It is well known that cattle will utilize riparian areas rather intensely under any stocking rate or grazing system (Hormay, in Armour 1977). This has led a number of wildlife and fishery biologists to suggest that riparian zones must either be fenced or treated as separate rotational pasture units in a grazing system (e.g., see Ames 1977; Behnke and Raleigh 1978; Thomas, Maser and Rodiek 1979). However, these alternatives are not acceptable to the livestock industry (Swan 1979), and they create access problems for wildlife and recreationists. It is important, then, to determine if more realistic management techniques can be devised which will fit into commercial grazing systems and still provide for riparian maintenance or enhancement.

For these and other reasons, the Eisenhower Consortium plan includes a second level of experimentation that would be superimposed at some point on the basic design previously described. This would be tailored more to the site-specific conditions of the watershed and riparian ecosystem, as well as to the interests of local ranchers, public land managers, and university scientists. The secondary experiments might involve studies on such things as cultural aids to riparian recovery (fertilization, replanting, treatment of woody vegetation to discourage browsing); differences in palatability among woody riparian species; simulation by mechanical means of cattle grazing and trampling effects on vegetation and soils; placing of salt, supplements, shading structures, windbreaks, and alternative sources of water in the uplands; behavior of cattle in the riparian zone; and utilization of the riparian and aquatic zones by wildlife and fish.

Values of Broader Regional Application

Although the basic grazing study would be an independent experiment capable of producing results that could be extrapolated to other sites in the immediate vicinity, the potential for much more powerful generalizations exists if several similar experiments are conducted in widely different locations. The Eisenhower Consortium plan calls for a minimum of four such experiments, each in a region characterized by a different major watershed vegetation type of importance to the cattle industry. Since climatic factors are not expected to be constant over the Eisenhower Consortium region, there would be no urgent need to initiate these experiments simultaneously. Instead, they could be set up incrementally, depending on the availability of funding.

The four major watershed types suggested are as follows: sagebrush steppe of southwestern Wyoming; juniper/pinyon woodland of western Colorado; grama/galleta steppe of northern and central New Mexico; and grama/tobosa shrub steppe of southeastern Arizona. If careful attention were given to criteria such as elevation, aspect, and slope at each location, these four semiarid ecosystem types would form an interesting gradient along a north-south transect from Wyoming

to Arizona. Differences among these ecosystems in amount of energy available for vegetative regeneration and growth would result primarily from differences in their characteristic length of growing season and daily temperatures during the growing season. Available energy would increase steadily from north to south, as would the general level of moisture stress in the ambient environment as measured by evapotranspiration potential. Data obtained from the different ecosystems on this transect could then be used to answer the following types of questions.

—Is the speed of recovery of woody riparian vegetation without grazing similar in the Colorado and New Mexico ecosystem types? Is recovery more rapid in these ecosystems than in those of Wyoming and Arizona where more severe limitations may exist as a result, respectively, of lower amounts of available energy and higher ambient moisture stress during seedling germination and establishment?

—Is exclosure from grazing for several years, followed by the rotation grazing system, a more effective way to stimulate recovery of herbaceous riparian vegetation in the Wyoming than in the Arizona ecosystem type?

—Do compacted riparian soils and unstable streambanks show some recovery over time in all ecosystems when subjected to the rotation grazing system from the start? Are there differences among ecosystems in these types of responses?

The extent to which these sorts of questions can be satisfactorily answered will depend on the maintenance of a reasonable amount of background constancy across locations for a group of important variables related to watershed, riparian communities, and grazing. For example, grazing management intensities (Laycock and Conrad 1981), stocking rates, and age-classes of cattle would need to be standardized as much as possible, in addition to the type and degree of previous overgrazing (Knopf and Cannon 1981), in order not to obscure effects of the different experimental grazing treatments and grazing system components. While the riparian and aquatic communities might differ considerably at each location, constancy could be maintained for factors such as number of vegetative layers, presence of obligate, woody, riparian vegetation, and size of the associated stream.

Cost

The set of four experiments suggested by the Eisenhower Consortium plan would be expensive. However, the total annual cost over all locations would not likely exceed that of the site-specific Saval Ranch study described above, in which the riparian studies are only one part. The costs of fencing and maintaining exclosures, and of payments to lease-holders for loss of production within exclosures and other inconveniences would be relatively small compared to those associated with salaries and travel of scientific personnel an technicians.

The Consortium Strategy

The regional nature of the Eisenhower Consortium makes it an effective vehicle for conducting this type of research. The Consortium could assemble by competitive means an interdisciplinary research team for each of the four experimental sites, drawing from the faculty pool of its nine member universities: Wyoming, Colorado State, Colorado, Texas Tech, New Mexico, New Mexico State, Northern Arizona, Arizona State, and Arizona. The tenth member of the Consortium is the Rocky Mountain Forest and Range Experiment Station of the FS. The researchers would be familiar with regional problems. Proximity of certain of the campuses to some or all of the experimental sites would decrease logistic problems and experimental costs. The Consortium would also have a "political" advantage resulting from previous contacts between its member universities and local ranchers and land managers.

The California Analogy

An analogy exists between the Eisenhower Consortium and its region, on the one hand, and the California system of state universities and colleges, on the other. It would appear desirable in California to integrate regionwide riparian research activities by means of some type of consortium structure. The University of California Natural Land and Water Reserves System might provide sites for a set of riparian projects. Alternately, a series of denovo sites could be selected as was in part done for the International Biological Programme Studies. One of the major advantages of an integrated regional approach is that it provides an opportunity to ask questions which, if properly framed, can provide more broadly generalizable answers. A less desirable alternative would be a series of completely independent, small projects springing up over time throughout the same region, involving more total cost, and providing less satisfying answers to important regional questions.

Once the initial investment has been made in a long-term, regional research project, the individual research sites have the potential of attracting funds for ancillary research. The longer the experimental sites are maintained and their baseline data accumulated, the more valuable they will become as locations for additional research efforts. Several workers have previously suggested that examples of different riparian communities should be protected over time as validation sites (Patton 1977), benchmarks (Moore etal . 1979) and places where, in general, concentration of efforts would produce maximum results (Claire and Storch 1977).

The Long-Term Ecological Research (LTER) program of the National Science Foundation should be considered as a potential source of funding for research on an integrated set of western U.S. riparian ecosystems. This program currently supports long-term studies on major ecosystem

types such as northern lakes, coniferous and deciduous forests, tallgrass prairies, and estuaries. Support of riparian research might require some adjustment in the LTER programmatic philosophy since riparian ecosystmes are not organized at major levels such as biomes. Their mature successional stages are also less stable, more open to nutrient and energy fluxes, and less likely to contain a characteristic group of stenotopic species than are many other ecosystem types. Nevertheless, their biological value is so high that they are worthy of greatly increased consideration by traditional funding sources for ecological research.

Literature Cited

Almand, J. David, and William B Krohn. 1978. The position of the Bureau of Land Management on the protection and mangement of riparian ecosystems. p. 359–361. In : R.R. Johnson and J.F. McCormick (tech. coord.). Strategies for protection and management of floodplain wetlands and other riparian ecosystems: Proceedings of the symposium. [Calloway Gardens, Ga., December 11–13, 1978] USDA Forest Service General Technical Report WO-12. 410 p. Washington, D.C.

Ames, Charles R. 1977. Wildlife conflicts in riparian management: grazing. p. 49–51. In : R.R. Johnson and D.A. Jones (tech. coord.). Importance, preservation and managment of riparian habitat: a symposium. [Tuscon, Ariz. July 9, 1977] USDA Forest Service Technical Report RM-43. 217 p. Rocky Mountain Forest and Range Experiment Station, Fort Collins, Colo.

Armour, Carl L. 1977. Effects of deteriorated range streams on trout. USDI Bureau of Land Management. 7 p. Idaho State Office, Boise Ida.

Armour, Carl L. 1979. Livestock management approaches and the fisheries resource. p. 39. In : O.B. Cope (ed.). Grazing and riparian/stream ecosystems: Proceedings of the forum. [Denver, Colo., November 3–4, 1978] Trout Unlimited Inc. 94 p. Denver, Colo.

Behnke, Robert J., and Robert F. Raleigh. 1978. Grazing and the riparian zone: impact and management perspectives. p. 263–267. In : R.R. Johnson, and J.F. McCormick (tech. coord.). Strategies for protection and management of floodplain wetlands and other riparian ecosystems: Proceedings of the symposium. [Calloway Gardens, Ga., December 11–13, 1978] USDA Forest Service General Technical Report WO-12. 410 p. Washington, D.C.

Beidleman, Richart G. 1978. The cottonwood-willow riparian ecosystem as a vertebrate habitat, with particular reference to birds. p. 192–195. In : W.D. Graul, and S.J. Bissell (tech. coord.). Lowland river and stream habitat in Colorado: a symposium. [Greeley, Colo., October 4–5, 1978] Colorado Chapter of Wildlife Society and Colorado Audubon Council. 195 p.

Benson, Patrick C. 1979. Land use and wildlife with emphasis on raptors. USDA Forest Service. 32 p. Intermountain Region.

Boldt, Charles E., Daniel W. Uresk, and Kieth Severson. 1978. Riparian woodlands in jeopardy on northern high plains. p. 184–189. In : R.R. Johnson and J.F. McCormick (tech. coord.). Strategies for protection and management of floodplain wetlands and other riparian ecosystems: Proceedings of the symposium. [Calloway Gardens, Ga., December 11–13, 1978] USDA Forest Service General Technical Riport WO-12. 410 p. Washington, D.C.

Burkhard, Walter T. 1978. Vertebrate associations in lowland versus high elevation river and stream habitat in Colorado. p. 52–55. In : W.D. Graul and S.J. Bissell (tech. coord.). Lowland river and stream habitat in Colorado: a symposium. [Greeley, Colo., October 4–5, 1978] Colorado Chapter of Wildlife Society and Colorado Audubon Council. 195 p.

Claire, E.W., and R.L. Storch. 1977. Streamside management and livestock grazing: an objective look at the situation. In : J.W. Menke (ed.). Livestock and wildlife-fisheries relationships in the Great Basin. [In press] USDA Forest Service. Pacific Southwest Forest and Range Experiment Station, Berkeley, Calif. (Cited in Moore, Elbert, Eric Janes, Floyd Kinsinger, Ken Pitney, and John Swainsbury. 1979. Livestock grazing management and water quality protection—state of the art reference document. U.S. Environmental Protection Agency, Seattle, Wash., and USDI Bureau of Land Management, Denver, Colo. 147 p.)

Crouch, Glenn L. 1978. Effects of protection from livestock grazing on a bottomland wildlife habitat in northeastern Colorado. p. 118–125. In : W.D. Graul and S.J. Bissell (tech. coord.). Lowland river and stream habitat in Colorado: a symposium. [Greeley, Colo., October 4–5, 1978] Colorado Chapter of Wildlife Society and Colorado Audubon Council. 195 p.

Dahlem, Eugene H. 1979. The Mahogany Creek watershed—with and without grazing. p. 31–34. In : O.B. Cope (ed.). Grazing and riparian/stream ecosystems: Proceedings of the forum. [Denver, Colo., November 3–4, 1978] Trout Unlimited Inc. 94 p. Denver, Colo.

Davis, Gary A. 1977. Management alternatives for the riparian habitat in the Southwest. p. 59–67. In : R.R. Johnson and D.A Jones (tech. coord.). Importance, preservation and management of riparian habitat: a symposium. [Tuscon, Ariz., July 9, 1977] USDA Forest Service Technical Report RM-43. 217 p. Rocky Mountain Forest and Range Experiment Station, Fort Collins, Colo.

Duff, Donald A. 1979. Riparian habitat recovery on Big Creek, Rich County, Utah—a summary of 8 years of study. p. 91–92. In : O.B. Cope (ed.). Grazing and riparian/stream ecosystems: Proceedings of the forum. [Denver, Colo., November 3–4, 1978] Trout Unlimited Inc. 94 p. Denver, Colo.

Fitzgerald, James P. 1978. Vertebrate associations in plant communities along the South Platte River in northeastern Colorado. p. 73–88. In : W.D. Graul and S.J. Bissell (tech. coord.). Lowland river and stream habitat in Colorado: a symposium. [Greeley, Colo., October 4–5, 1978] Colorado Chapter of Wildlife Society and Colorado Audubon Council. 195 p.

Glinski, Richard L. 1977. Regeneration and distribution of sycamore and cottonwood trees along Sonoita Creek, Santa Cruz County, Arizona. p. 116–123. In : R.R. Johnson and D.A. Jones (tech. coord.). Importance, preservation and management of riparian habitat: a symposium. [Tuscon, Ariz., July 9, 1977] USDA Forest Service Technical Report RM-43. 217 p. Rocky Mountain Forest and Range Experiment Station, Fort Collins, Colo.

Johnson, R.R. 1971. Tree removal along the southwestern rivers and effects on associated organisms. American Philosophical Society Yearbook, 1970. p. 321–323.

Johnson, R. Roy, and Steven W. Carothers. 1975. The effects of stream channel modifications on birds in the southwestern United States. In : Proceedings of symposium on stream channel modification. [Harrisburg, Va., August 15–17, 1975]

Johnson, R. Roy, and Steven W. Carothers. 1981. Southwestern riparian habitats and recreation: interrelationships and impacts in the Rocky Mountain Region. Eisenhower Consortium Bulletin. [In press] USDA Forest Service. Rocky Mountain Forest and Range Experiment Station, Fort Collins, Colo.

Johnson, R. Roy, Lois T. Haight, and James M. Simpson. 1977. Endangered species vs. endangered habitats: a concept. p. 68–74. In : R.R. Johnson and D.A. Jones (tech. coord.). Importance, preservation and management of riparian habitat: a symposium. [Tuscon, Ariz., July 9, 1977] USDA Forest Service Technical Report RM-43. 217 p. Rocky Mountain Forest Range Experiment Station, Fort Collins, Colo.

Keller, Charles, Loren Anderson, and Paul Tappel. 1979. Fish habitat changes in Summit Creek, Idaho, after fencing the riparian area. p. 46–52. In : O.B. Cope (ed.). Grazing and riparian/stream ecosystems: Proceedings of the forum. [Denver, Colo., November 3–4, 1978] Trout Unlimited Inc. 94 p. Denver, Colo.

Knopf, Fritz L., and Richard W. Cannon. 1981. Structural resilience of a willow riparian community to changes in grazing practices. In : J. Peek (ed.). Livestock-wildlife relationships symposium. [Coeur D'Alene, Idaho, April, 1981. In press.] University of Idaho, Moscow, Ida.

Laycock, W.A., and P.W. Conrad. 1981. Responses of vegetation and cattle to various systems of grazing on seeded and native mountain rangelands in eastern Utah. Journal of Range Management 34:52–58.

Lea, George D. 1979. BLM management and policy for riparian/stream ecosystems. p. 13–15. In : O.B. Cope (ed.). Grazing and riparian/stream ecosystems: Proceedings of the forum. [Denver, Colo., November 3–4, 1978] Trout Unlimited Inc. 94 p. Denver, Colo.

Martin, S. Clark. 1979. Evaluating the impacts of cattle grazing on riparian habitats in the national forests of Arizona and New Mexico. p. 35–38. In : O.B. Cope (ed.). Grazing and riparian/stream ecosystems: Proceedings of the forum. [Denver, Colo., November 3–4, 1978] Trout Unlimited Inc. 94 p. Denver, Colo.

Moore, Elbert, Eric Janes, Floyd Kinsinger, Ken Pitney, and John Swainbury. 1979. Livestock grazing management and water quality protection—state of the art reference document. U.S. Environmental Protection Agency, Seattle, Wash., and USDI Bureau of Land Management, Denver, Colo. 147 p.

Myers, L.H. 1981. Grazing management vs. riparian management in southwestern MontanA . In : Proceedings on management of riparian ecosystems. [In press.] Montana Chapter of the Wildlife Society, Great Falls, Mont. (Cited in Knopf, Fritz L., and Richard W. Cannon. 1981. Structural resilience of a willow riparian community to changes in grazing practices. In : James Peek (ed.). Livestock-wildlife relationships symposium. [Coeur D'Alene, Idaho, April, 1981. In press.] University of Idaho, Moscow, Ida.)

Patton, David R. 1977. Riparian research needs. p. 80–82. In : R.R. Johnson and D.A. Jones (tech. coord.). Importance, preservation and management of riparian habitat: a symposium. [Tuscon, Ariz., July 9, 1977] USDA Forest Service Technical Report RM-43. 217 p. Rocky Mountain Forest and Range Experiment Station, Fort Collins, Colo.

Platts, William S. 1979. Livestock grazing and riparian/stream ecosystems—an overview. p. 39–45. In : O.B. Cope (ed.). Grazing and riparian/stream ecosystems: Proceedings of the forum. [Denver, Colo., November 3–4, 1978] Trout Unlimited Inc. 94 p. Denver, Colo.

Raleigh, Robert F. 1979a. Introduction. p. 1. In : O.B. Cope (ed.). Grazing and riparian/stream ecosystems: Proceedings of the forum. [Denver, Colo., November 3–4, 1978] Trout Unlimited Inc. 94 p. Denver, Colo.

Raleigh, Robert F. 1979b. Closing remarks. p. 89–90. In : O.B. Cope (ed.). Grazing and riparian/stream ecosystems: Proceedings of the forum. [Denver, Colo., November 3–4, 1978] Trout Unlimited Inc. 94 p. Denver, Colo.

Salt, G.W. 1957. An analysis of the avifaunas in the Teton Mountains and Jackson Hole, Wyoming. Condor 59:373–393.

Schrupp, Donald L. 1978. The wildlife values of lowland river and stream habitat as related to other habitats in Colorado. p. 42–51. In : W.D. Graul and S.J. Bissell (tech. coord.). Lowland river and stream habitat in Colorado: a symposium. [Greeley, Colo., October 4–5, 1978] Colorado Chapter of Wildlife Society and Colorado Audubon Council. 195 p.

Severson, Kieth E, and Charles E. Boldt. 1978. Cattle, wildlife, and riparian habitats in the western Dakotas. In : Management and use of northern plains rangeland. Regional rangeland symposium. [Bismark, No. Dak., February 27–28, 1978].

Smith, Felix E. 1980. A short review of the status of riparian forests in California. p. 1–2. In : A. Sands (ed.). Riparian forests in California—their ecology and conservation: Proceedings of the symposium. [Davis, Calif., May 14, 1977] Division of Agricultural Sciences, University of California, Berkeley, Calif. 122 p.

Stevens, Lawrence E., Bryan T. Brown, James M. Simpson, and R. Roy Johnson. 1977. The importance of riparian habitats to migrating birds. p. 156–164. In : R.R. Johnson and D.A. Jones (tech. coord.). Importance, preservation and management of riparian habitat: a symposium. [Tuscon, Ariz., July 9, 1977] USDA Forest Service Techical Report RM-43. 217 p. Rocky Mountain Forest and Range Experiment Station, Fort Collins, Colo.

Stoddart, Laurence A., Arthur D. Smith, and Thadis W. Box. 1975. Range management. Third edition. 532 p. McGraw-Hill Book Co., New York, N.Y.

Storch, Robert L. 1979. Livestock/streamside management programs in eastern Oregon. p. 56–59. In : O.B. Cope (ed.). Grazing and riparian/stream ecosystems: Proceedings of the forum. [Denver, Colo., November 4–5, 1978] Trout Unlimited Inc. 94 p. Denver, Colo.

Swan, Bill. 1979. Riparian habitat—the cattlemen's viewpoint. p. 4–6. In : O.B. Cope (ed.). Grazing and riparian/stream ecosystems: Proceedings of the forum. [Denver, Colo., November 4–5, 1978] Trout Unlimited Inc. 94 p. Denver, Colo.

Thomas, Jack Ward, Chris Maser, and Jon E. Rodiek. 1979. Wildlife habitats in managed rangelands—the Great Basin of southeastern Oregon—riparian zones. USDA Forest Service General Technical Report PNW-80. 18 p. Pacific Northwest Forest and Range Experiment Station, La Grande, Ore. (Also published under the title "Riparian zones in managed rangelands—their importance to wildlife." 1979. p. 21–31. In : O.B. Cope (ed.). Grazing and riparian/stream ecosystems: Proceedings of the forum. [Denver, Colo., November 4–5, 1978] Trout Unlimited Inc. 94 p. Denver, Colo.)

US Council on Environmental Quality. 1978. Environmental quality. The Ninth Annual Report of the Council on Environmental Quality. 599 p. US Government Printing Office, Washington, D.C. [Stock No. 041011-00040-8]

USDI Bureau of Land Management. Draft environmental statement on grazing management in the Missouri Breaks of Montana. Montana State Office.

Warner, Richard E. (recorder). 1979a. Fish and wildlife resource needs in riparian ecosystems: Proceedings of a workshop. [Harpers Ferry, W. Va., May 30–31, 1979] 53 p. National Water Resources Analysis Group, Eastern Energy and Land Use Team, USDI Fish and Wildlife Service, Kearneysville W. Va.

Warner, Richard E. 1979b. California riparian study program: background information and proposed study design. 177 p. Planning Branch, California Department of Fish and Game, Sacramento, Calif.