Paired Watershed Research Articles

Evaluating Watershed Experiments through Recursive Residual Analysis

The question of watershed response to changes in land use and land cover has received a great deal of attention in the hydrologic literature. One of the primary tools for quantifying such changes has been the paired watershed approach. In general this approach applies a linear regression analysis to relate water yield from a control watershed to a physiographically similar watershed in close proximity, and to predict changes in yield following treatment. Although much research on paired watershed experiments has focused on quantification of the impacts of land-use and land cover changes on water yield, little attention has been brought to evaluating explicitly the methodology used to quantify such effects. An alternative method is proposed for examining treatment impacts and their duration, through the application of a cumulative recursive residual test of model stability. The results from a paired watershed study of ponderosa pine watersheds in north-central Arizona are analyzed using both a traditional linear regression analysis and a recursive residuals approach. The results suggest that the linear regression approach may fail to account for the true complexity of watershed response to vegetation treatments, by underestimating the interactions of treatment impacts, shifts in climatic drivers, and revegetation rates.

Effects of Hydrodynamically Rough Grassed Waterways on Dissolved Reactive Phosphorus Loads Coming from Agricultural Watersheds

A modified type of grassed waterway (GWW) with large hydrodynamic roughness has proven ability to reduce sediment load and surface runoff under conditions where best management practices on the delivering fields reduce sediment inputs that could otherwise damage the grass cover. It is unknown how such a GWW affects the loading of surface runoff with dissolved reactive phosphorus (DRP). The effect on DRP was tested in a landscape-scale study where DRP concentrations and loads in surface runoff were measured in two watersheds in which GWWs were newly installed and increased in effectiveness over time. Both watersheds were compared with paired watersheds without GWW installation; all watersheds were continuously monitored over 5 yr (1993-1997). Additionally, DRP concentrations were measured in open field and throughfall precipitation under growing grass and crops in field experiments, and DRP concentrations in surface runoff from straw covered surfaces were determined with laboratory rainfall simulation experiments. Dissolved reactive P in throughfall for the different cover types was highly variable, and the highest concentrations (up to 2.8 mg L(-1)) occurred especially during flowering of the respective crop and after frost events. Dissolved reactive P concentrations in runoff from straw-covered surfaces were slightly higher compared with those from bare soil. On average, there was a small difference in DRP concentrations between throughfall under growing crops and grass and in runoff from bare or straw covered soil surfaces. Hence, the introduction of a relatively small grassed area has little effect on the DRP concentration in surface runoff from the total watershed. This finding was supported by the watershed data, where watersheds with and without GWW showed similar DRP concentrations. No change in DRP concentrations occurred over the 5-yr period. Such GWWs will thus reduce the DRP load analogously to the reduction in total surface runoff.

Assessment of ecosystem services as an opportunity for the conservation and management of native forests in Chile

This paper quantifies two important native forest ecosystem services in southern Chile: water supply and recreational fishing opportunities. We analyzed streamflow in relation to forest cover in six watersheds located in the Valdivian Coastal Range (39°50′–40°05′S), the effect of forest management on streamflow in two watersheds in the Valdivian Andes (600–650 m of elevation; 39°37′S), and fish abundance as a function of forest cover in 17 watersheds located in the Coastal Range and the Central Depression (39°50′–42°30′S). We found that the annual direct runoff coefficient (quickflow/precipitation) and total streamflow/precipitation in the dry summer season were positively correlated with native forest cover in the watershed ( R 2 = 0.67 and 0.76; * P = 0.045 and 0.027, respectively) during four years of observations. Conversely, a negative correlation was found between summer runoff coefficients (total streamflow/precipitation) and cover of Eucalyptus spp. and Pinus radiata plantations ( R 2 = 0.84; * P = 0.010). We estimated a mean increase of 14.1% in total summer streamflow for every 10% increase in native forest cover in the watershed. The analysis of streamflow changes between two paired watersheds dominated by native secondary Nothofagus stands, one thinned with 35% of basal area removal and a control, showed that the former had a 40% increase during summer (four years of observations). The best correlation between fish abundance and forest cover was found between trout abundance (%) and secondary native forest area in 1000 m × 60 m stream buffers ( R 2 = 0.65, *** P < 0.0001). We estimated a 14.6% increase in trout abundance for every 10% increase of native forest cover in these buffers. Similar approaches to quantify forest ecosystem services could be used elsewhere and provide useful information for policy and decision-making regarding forest conservation and management.

Responses of water yield to changes in vegetation at a temporal scale

The effect of vegetation on the water recycling of a land ecological system is considerably significant. Understanding the relationship between vegetation and runoff changes will benefit regional eco-environmental and water resources management. Based on paired catchments and time trend studies, a number of studies had been undertaken to establish the relationship between vegetation cover and water yield. We obtained some results from paired watersheds by focusing on changes at various time scales. At the mean annual scale the runoff changes resulting from vegetation alteration can be predicted using Zhang’s curves. The absolute change of runoff due to vegetation alteration in a humid area is larger than that in the dry region, while the relative change is reverse. At the annual scale, it takes 15-20 years or longer in the arid region for catchments to reach a new equilibrium after afforestation, and under natural restoration, it takes about a hundred years. The vegetation changes have a proportionally larger impact on low flow at the seasonal scale. For catchments in arid regions, relative changes in low flow sections of the flow duration curve will be much more significant compared with that in the high flow section, leading to increased number of zero-flow days. However, in humid regions, changes in runoff tend to be much more uniform.

Validation of paired watersheds for assessing conservation practices in the Upper Big Walnut Creek watershed, Ohio

Impacts of watershed scale conservation practice adoption on sediment, nutrient, and pesticide losses and adjacent stream biota are not well understood. The objective of this study was to examine the suitability of selected paired watersheds to quantify hydrology, chemical, and ecology effects of conservation practice implementation for channelized and unchannelized watersheds in Upper Big Walnut Creek watershed, Ohio. Channelized watersheds were more similar in watershed characteristics than the unchannelized watersheds. One hydrology, eight water chemistry, and five fish community response variables were measured. Most response variables in both watershed pairs were moderately correlated (r > 0.6), but the minimum percent change required to detect a response difference was greater for the unchannelized watersheds. Detectable temporal trends in the difference between like response variables for the channelized and unchannelized watershed pairs were minimal. These results validate the paired watershed design and suggest that conservation practice induced changes in hydrology, water quality, and fish communities can be quantified.

The Forest‐Streamflow Relationship in China: A 40‐Year Retrospect1

Abstract: The relationship between forests and streamflows has long been an important research interest in China. The purpose of this paper is to summarize progress and lessons learned from the forest‐streamflow studies over the past four decades in China. To better measure the research gaps between China and other parts of the world, a brief global review on the findings from paired watershed studies over the past 100 years was also provided. In China, forest management shifted in the later 1990s from timber harvesting to forest restoration. Forest‐streamflow research was accordingly changed from assessing harvesting impacts to evaluating both harvesting and forestation effects. Over the past four decades, Chinese forest hydrology research has grown substantially. Significant progress has been made on measuring individual processes, but little solid, long‐term data were available to assess the relationship between forest changes and streamflows because of an absence of standard paired watersheds. In addition, misuse of statistical analyses was often found in the literature. A unique opportunity exists in China to study the forestation effects on streamflow as several large‐scale forestation programs are being implemented. Such an opportunity should include a robust paired watershed design under an integrated watershed ecosystem framework to avoid repeating the lessons already learned. Recommendations on future forest‐streamflow research directions in China are provided.

Measuring the Impact of Urbanization on Channel Widths Using Historic Aerial Photographs and Modern Surveys1

Abstract: Land use in a watershed is commonly held to exert a strong influence on trunk channel form and process. Land use changes act over human time‐scales, which are short enough to measure effects on channels directly using historic aerial photographs. We show that high‐resolution topographic surveys for the channels of paired watersheds in the Lehigh Valley, Pennsylvania, are comparable, but have channel widths that have changed dramatically in the past five decades. The two watersheds, Little Lehigh Creek and Sacony Creek, are similar in most aspects except in their respective amount of urban land use. Aerial photographs of the urbanized Little Lehigh Creek show that a majority of the measured widths (67 of 85) were statistically wider in 1999 than in 1947. In contrast, the measured widths from the agricultural Sacony Creek are more evenly distributed among those that widened (18), narrowed (28), and those that were statistically unchanged (6) from 1946 to 1999. From 1946 to 1999 the only section of Sacony Creek that widened was that reach downstream of the only sizable urban area in the watershed. The current land use in Sacony Creek watershed resembles that of 1946, while the Little Lehigh Creek watershed has more than tripled its urban area. These data, in concert with other recent hydrologic data from the watersheds suggest that the increase in urban area‐generated peak discharges is the mechanism behind the widening that occurred in the Little Lehigh Creek. These wider channels can affect water quality, aquatic habitat, suspended sediment loads, and river esthetics.

Stream acidification and base cation losses with grassland afforestation

Afforestation of natural grasslands with fast‐growing pine and eucalyptus species is increasing globally, but little is known about its effect on ecosystems and watersheds and, ultimately, the quality of water resources. To investigate the biogeochemical and hydrological consequences of this land use change, we sampled stream water in paired watersheds in Uruguay and Argentina. In watersheds planted with pine, we found no change in stream pH following afforestation, while in watersheds planted with eucalyptus, pH was 0.7 units lower on average than in streams draining grasslands. To further investigate the mechanism behind the decrease in pH, we sampled soils and streams of eucalypt catchments in Uruguay and analyzed exchangeable base cation concentrations, alkalinity, and dissolved inorganic carbon (DIC). At these sites, Ca, Mg, and Na concentrations were &gt;30% lower in afforested soils than in grassland soils, and pH was significantly lower below 10 cm depth. Stream measurements taken over three years illustrate that these soil changes were also manifested in stream water chemistry. In the eucalypt watersheds, base cation concentrations were &gt;40% lower, and alkalinity and DIC were halved in stream water. A test with data from additional sites where both pines and eucalypts were planted nearby showed that eucalyptus has a stronger acidifying effect than pine. Overall, our data suggest that repeated harvesting cycles at some locations could negatively impact the soil store of base cations and reduce downstream water quality. Our results can be used to help minimize negative impacts of this land use and to inform policy in this and other regions targeted for plantation forestry.

Effects of Timber Harvest on Suspended Sediment Loads in Mica Creek, Idaho

Abstract Long-standing concerns exist regarding timber harvest and subsequent sediment impacts on aquatic resources. Intensive studies on contemporary harvest practices remain rare, particularly in the interior Pacific Northwest. To investigate this, a network of seven automated stream monitoring flumes was installed in the Mica Creek Experimental Watershed, in northern Idaho. Beginning in 1991, water samples collected at each flume under both flow-based and stream-stage storm rise conditions have been analyzed for total suspended solids (TSS). This period of record encompasses a pretreatment time interval from 1991 to 1997, and two treatment time intervals: post-road from 1998 to 2001 and post-road/post-harvest from 2001 through 2004. Treated and control catchments were statistically compared using a paired watershed approach for immediate and recovery time intervals corresponding to each treatment activity, road construction and timber harvest. The impacts corresponding to road construction remain difficult to discern. The impacts corresponding to timber harvest differ based on harvest treatment and time period of analysis. Results suggest a correlation between increased sediment loads and clearcutting for a brief period following the harvest. No significant correlation was found in the partial cut watershed. Continued monitoring at these sites is planned to evaluate trends over subsequent years.

Long‐Term Effects of Poultry Litter, Alum‐Treated Litter, and Ammonium Nitrate on Phosphorus Availability in Soils

Alum (Al2(SO4)(3).14H2O) additions to poultry litter result in lower ammonia (NH3) volatilization and phosphorus (P) runoff; however, the long-term effects of alum on soil P behavior have been unknown. The objectives of this study were to evaluate the long-term effects of poultry litter, alum-treated litter, and ammonium nitrate (NH4NO3) on P availability in soils and P runoff. Two studies were initiated in 1995: a small plot (1.5x3.0 m) study and a paired watershed (0.405 ha) study. In the small plot study 13 treatments (control, four rates of normal litter, four rates of alum-treated litter, and four rates of NH4NO3) were applied to tall fescue (Festuca arundinacea Schreb.) plots. Results show that after 7 yr water-extractable P (WEP) in surface soil samples was greater with normal litter, but Mehlich III P was greater in surface soils fertilized with alum-treated litter. When soil samples were taken at depth intervals to 50 cm in Year 7, Mehlich III P was only greater in the surface 5 cm for soils fertilized with alum-treated litter. At lower depths Mehlich III P was greater with normal litter, and WEP was up to 288% greater when normal litter was used, indicating that alum significantly reduced P leaching. Uptake of P by fescue was not affected by alum. Results from the paired watershed study showed P loss in runoff was 340% greater for normal litter than for alum-treated litter. This research, combined with earlier work that shows alum use improves air and soil quality, supports the use of alum as a long-term solution to reducing P runoff and leaching.

Aerating Grasslands

Aeration has been promoted as improving infiltration of rainfall and extending grass or forage productivity, but research on the impact of this practice on P losses from grasslands has had mixed results. We designed a study to determine at the field scale, using a paired watershed approach, the impact of slit aeration on runoff volume and P losses in runoff from fescue (Festuca arundinacea Schreb.)/bermudagrass (Cynodon dactylon L.) hay fields fertilized with broiler litter. Three pairs of 0.8-ha fields, each with similar soils (Typic Kanhapludults, Aquic Hapludults, and Aquultic Hapludalfs), were fertilized with broiler litter and monitored under similar management from 1995 through 1998, then one field in each pair received aeration treatment from 2001 through 2003. In the field with mostly well-drained soils, grassland aeration reduced surface runoff volume and mass losses of dissolved reactive P (DRP) in runoff by approximately 35%. In contrast, when poorly drained soils dominated, grassland aeration increased runoff volume (4.8 mm/runoff event) and mass losses of DRP and total P (0.25 kg TP ha-1 per runoff event). This implies that aeration of well-drained soils in the top poultry-producing counties of Georgia (0.2 million ha) could decrease dissolved phosphorus losses by more than 500 Mg P each year. This is not the case if soils are poorly drained.

The use of sediment budget concepts to assess the impact on watersheds of forestry operations in the southern interior of British Columbia

Sediment budget concepts can be applied to the assessment of the impacts of forest resource development on the sediment regime of streams. In British Columbia, these impacts are of concern because of the extent of commercially valuable forests. Increases in sediment yield from forestry operations can affect water quality, fish habitat, and channel stability. To address these concerns, the BC Ministry of Forests conducted several sediment budget studies from about 1992 to 2002. This paper reports the results of two studies, focusing on the water quality of streams used for community water supply. The studies address several questions: How sensitive are the streams to an increase in sediment supply? Are development-related sediment sources significant compared to natural sources? What forest practices are responsible for increasing or minimizing sediment impacts? How can the impact of forestry operations on water quality be monitored? The studies used a paired watershed approach, with discharge, turbidity, sediment yield, and solute yield measured on watersheds undergoing logging and road building, and on similar undeveloped watersheds. The studies concluded that erosion from forest roads can be a significant source of suspended sediment, but sediment from logging operations is usually negligible. The risk of landslides is an important factor in the sediment budgets, but is difficult to quantify. Differences in geology and groundwater regime can influence the sensitivity of watersheds to sediment impacts.

05/01633 A new liquid hold-up correlation for geothermal wells

Globally, rangeland has been undergoing a transition from herbaceous dominated grasslands into tree or shrub dominated woodlands with great uncertainty of associated changes in water budget. Previous modeling studies simulated the impact of woody plant encroachment on hydrological processes using models calibrated and constrained primarily by historic streamflow from intermediate sized watersheds. In this study, we calibrated the Soil and Water Assessment Tool (SWAT model), a widely used model for cropping and grazing systems, for a prolifically encroaching juniper species, eastern redcedar (Juniperus virginiana), in the south-central Great Plains using species-specific biophysical and hydrological parameters and in situ meteorological forcing from three pairs of experimental watersheds (grassland versus eastern redcedar woodland) for a period of 3-years covering a dry-to-wet cycle. The multiple paired watersheds eliminated the potentially confounding edaphic and topographic influences from changes in hydrological processes related to woody encroachment. The SWAT model was optimized with the Shuffled complexes with Principal component analysis (SP-UCI) algorithm developed from the Shuffled Complexes Evolution (SCE_UA). The mean Nash–Sutcliff coefficient (NSCE) values of the calibrated model for daily and monthly runoff from experimental watersheds reached 0.96 and 0.97 for grassland, respectively, and 0.90 and 0.84 for eastern redcedar woodland, respectively. We then validated the calibrated model with a nearby, larger watershed undergoing rapid eastern redcedar encroachment. The NSCE value for monthly streamflow over a period of 22 years was 0.79. We provide detailed biophysical and hydrological parameters for tallgrass prairie under moderate grazing and eastern redcedar, which can be used to calibrate any model for further validation and application by the hydrologic modeling community.

Effect of fall tillage following soybeans on organic matter losses in snowmelt

In a corn–soybean rotation, maintaining crop residue on the soil surface is a challenge following soybeans. Often farmers are encouraged not to till the soil following a soybean crop in order to maximize the amount of residue at the soil surface. In this study we evaluated the effect of this practice compared to fall moldboard plowing on snowmelt runoff and losses of total solids (TS) and organic carbon (using oxygen demand in runoff as a surrogate). A paired watershed approach was used to evaluate the effect of these management practices. Individual hydrographs were compared and contaminant losses in runoff calculated. Results show that snowmelt runoff and the associated losses of total solids, chemical oxygen demand (COD), and biochemical oxygen demand (BOD) were less with fall moldboard plowing compared to no fall tillage following soybean (0.22 cm, 1.9 kg ha −1, 0.81 kg ha −1, 74 g ha −1, reduction in median value per melt cycle, respectively). In areas where snowmelt runoff is an important component of annual runoff, some tillage in the fall would be preferable to no-tillage in order to reduce snowmelt runoff losses.

RUNOFF AND SEDIMENT RESPONSES TO CONSERVATION PRACTICES: LOESS PLATEAU OF CHINA1

ABSTRACT: Soil erosion is the most significant threat to land productivity and environmental quality on the Loess Plateau of China. The annual total sediment load of the Yellow River is 1.6 billion tons, with about 90 percent coming from soil erosion from the Loess Plateau. To reduce soil erosion from the Loess Plateau, conservation practices, including tree planting, ridge construction between fields and around gullies, terrace and ditch construction perpendicular to the main slope, and dam construction are being implemented. An evaluation of these conservation practices is required before they are implemented at the large scale. The objective of this study is to evaluate the effectiveness of conservation practices to control runoff and sediment yield from paired watersheds in the hilly gully region of the Loess Plateau. The advantage of the paired watershed approach is its sensibility in detecting differences in runoff and sediment transport by monitoring both watersheds during two periods, an initial period with no conservation practices and a treatment period with only one watershed subjected to conservation practices. Implementation of the conservation practices resulted in (1) cumulative runoff and sediment yield that were, respectively, 25 and 38 percent less from the treatment watershed than from the control, (2) a decrease in the number of rainfall events producing runoff and sediment transport (94 in the control versus 63 in treatment), and (3) a reduction in the maximum discharge and maximum suspended sediment concentration.

Runoff responses to afforestation in a watershed of the Loess Plateau, China

AbstractAfforestation has been suggested as a means of improving soil and water conservation in north‐western China, especially on the Loess Plateau. Understanding of the hydrological responses to afforestation will help us develop sustainable watershed management strategies. A study was conducted during the period of 1956 to 1980 to evaluate runoff responses to afforestation in a watershed on the Loess Plateau with an area of 1·15 km2, using a paired watershed approach. Deciduous trees, including locust (locusta L.), apricot (praecox L.) and elm (ulmus L.), were planted on about 80% of a treated watershed, while a natural grassland watershed remained unchanged. It was estimated that cumulative runoff yield in the treated watershed was reduced by 32% as a result of afforestation. A significant trend was also observed that shows annual runoff reduction increases with the age of the trees planted. Reduction in monthly runoff occurred mainly from June to September, which was ascribed to greater rainfall and utilization by trees during this period. Afforestation also resulted in reduction in the volume and peak flow of storm runoff events in the treated watershed with greater reduction in peak flow. Copyright © 2003 John Wiley &amp; Sons, Ltd.

Effectiveness of grassed waterways in reducing runoff and sediment delivery from agricultural watersheds.

Grassed waterways (GWWs) drain surface runoff from fields without gullying along the drainageway. Secondary functions include reducing runoff volume and velocity and retaining sediments and harmful substances from adjacent fields. Grass cover (sward)-damaging sedimentation in the GWW is commonly reduced by frequent mowing, but in doing so the effectiveness of the waterway relative to the secondary functions is reduced. Our objectives were to (i) evaluate whether the maintenance of a GWW can be reduced if on-site erosion control is effective, (ii) measure the effectiveness of such a GWW, and (iii) analyze the underlying mechanisms. A long-term (1994-2000) landscape experiment was performed in four watersheds, where two had GWWs for which maintenance was largely neglected. An intensive soil conservation system was established on all fields. Runoff and sediment delivery were continuously measured in the two watersheds with GWWs and in their paired watersheds that were similar, but without GWWs. Runoff was reduced by 90 and 10% for the two sets of paired watersheds, respectively. The different efficiencies of the GWWs resulted from different layouts (doubled width and flat-bottomed vs. v-shaped drainageway). The GWWs reduced sediment delivery by 97 and 77%, respectively, but the sward was not damaged by sedimentation. Grain sizes > 50 microm were settled due to gravity in both GWWs. Smaller grain sizes were primarily settled due to infiltration, which increased with a more effective runoff reduction. In general, the results indicated a high potential of GWWs for reducing runoff volume and velocity, sediments, and agrochemicals coming from agricultural watersheds.

Impacts of eucalyptus ( Eucalyptus exserta) plantation on sediment yield in Guangdong Province, Southern China—a kinetic energy approach

The relationship between the kinetic energy of waterdrops (rainfall and throughfall) and sediment yield (suspended solid (SS) and bed load (BL)) was studied in paired watersheds (one without vegetation and the other covered by an eucalyptus ( Eucalyptus exserta) plantation) in Guangdong Province, Southern China. The results showed that there was a significant correlation between the kinetic energy of waterdrops and sediment yield in both watersheds. Sediment yield in the unvegetated watershed is significantly affected by the kinetic energy of atmospheric raindrops. Sediment yield in the plantation watershed, however, is significantly related to the kinetic energy of throughfall waterdrops, but not to the atmospheric rainfall intensity or the rainfall kinetic energy. When rainfall amount is greater than 5 mm, and their intensities are less than 20 mm h −1, the single-layer eucalyptus plantations significantly increased the kinetic energy of waterdrops to the land surface, and consequently, accelerated soil erosion. However, these plantations do have positive impacts on the reduction of soil erosion for the rainfall events of larger intensities (particularly >40 mm h −). Management implications of these results are discussed in the context of soil protection xxxxxxxxand ecosystem rehabilitation.

Effects of Nitrogen Enrichment, Wildfire, and Harvesting on Forest‐Soil Carbon and Nitrogen

Northern forest soils represent large reservoirs of C and N that may be altered by ecosystem perturbations. Soils at three paired watershed in Maine were investigated as case studies of experimentally elevated N deposition, wildfire, and whole‐tree harvesting. Eight years of experimental (NH4)2SO4 additions at the Bear Brook Watershed in Maine significantly reduced forest‐floor C/N ratios from 30.6 to 23.4. Forest‐floor C and N pools were lower in the treated watershed (38 Mg C ha−1, 1612 kg N ha−1) compared with the reference (75 Mg C ha−1, 2372 kg N ha−1). Fifty years after wildfire at Acadia National Park, the burned watershed with hardwood regeneration had significantly lower forest‐floor C and N concentrations (208 g C kg−1 soil, 9.9 g N kg−1 soil) than the reference watershed dominated by a softwoods (437 g C kg−1 soil, 12.8 g N kg−1 soil). Forest‐floor C and N pools were lower in the burned watershed (27 Mg C ha−1, 1323 kg N ha−1) compared with the reference (71 Mg C ha−1, 2088 kg N ha−1). At the Weymouth Point, the harvested watershed regenerated to spruce‐fir, the dominant stand type that existed before the harvest, and it had significantly lower forest‐floor C concentrations and pools (406 g C kg−1 soil, 24 Mg C ha−1) than the reference (442 g C kg−1 soil, 39 Mg C ha−1) after 17 yr. All perturbations studied were associated with lower forest‐floor C pools.

Impacts of Rotational Grazing and Riparian Buffers on Physicochemical and Biological Characteristicsof Southeastern Minnesota, USA, Streams

We assessed the relationship between riparian management and stream quality along five southeastern Minnesota streams in 1995 and 1996. Specifically, we examined the effect of rotationally and continuously grazed pastures and different types of riparian buffer strips on water chemistry, physical habitat, benthic macroinvertebrates, and fish as indicators of stream quality. We collected data at 17 sites under different combinations of grazing and riparian management, using a longitudinal design on three streams and a paired watershed design on two others. Continuous and rotational grazing were compared along one longitudinal study stream and at the paired watershed. Riparian buffer management, fenced trees (wood buffer), fenced grass, and unfenced rotationally grazed areas were the focus along the two remaining longitudinal streams. Principal components analysis (PCA) of water chemistry, physical habitat, and biotic data indicated a local management effect. The ordinations separated continuous grazing from sites with rotational grazing and sites with wood buffers from those with grass buffers or rotationally grazed areas. Fecal coliform and turbidity were consistently higher at continuously grazed than rotationally grazed sites. Percent fines in the streambed were significantly higher at sites with wood buffers than grass and rotationally grazed areas, and canopy cover was similar at sites with wood and grass buffers. Benthic macroinvertebrate metrics were significant but were not consistent across grazing and riparian buffer management types. Fish density and abundance were related to riparian buffer type, rather than grazing practices. Our study has potentially important implications for stream restoration programs in the midwestern United States. Our comparisons suggest further consideration and study of a combination of grass and wood riparian buffer strips as midwestern stream management options, rather than universally installing wood buffers in every instance. RID="" ID="" The Unit is jointly sponsored by the US Geological Survey, Biological Resources Division; the Minnesota Department of Natural Resources; the University of Minnesota; and the Wildlife Management Institute.