Natural Resources and Environmental Issues

A Fisheries Investigation of the Previously Un-Surveyed Little Bear River

Christian Smith — Tue, 13 Aug 2013 09:01:05 PDT

To evaluate the effects of human impacts on the composition and abundances of fishes on the Little Bear River, the 2012 Aquatic Ecology Practicum class conducted backpack electrofishing surveys in four sites of the river on 29 September and 4 October 2012. At these sites, species composition, biomass, and abundances were documented utilizing 2-pass electrofishing. In total, ten species were captured, with native species being represented by Bonneville cutthroat trout (Oncoryhnchus clarki Utah) and mottled sculpin (Cottus bairdii). Mottled sculpin comprised the majority of native fish captured (n= 241), while brown trout accounted for the majority of nonnatives (n= 129). Brown trout abundance was highest at the most upstream site (Station 2) and decreased going down the longitudinal gradient. Regression analysis revealed that larger average pebble size at Station 2 could be a factor in determining the observed higher brown trout abundance at this site, although the small sample size warrants further investigation. At the lowest site (Station 11) with poor water quality, only introduced species were present: green sunfish (Lepomis cyanellus), common carp (Cyprinus carpio), largemouth bass (Micropterus salmoides) and sand shiner (Notropis stramineus). Recommendations for future fisheries investigations on the Little Bear River include the sampling of additional sites, inclusion of more passes per site, and additional invertebrate and pebble sampling. Management recommendations include assessment of the potential value of a fisheries management program on the Little Bear River.

Benthic Invertebrate Composition along the Little Bear River Continuum

Jared Baker et al. — Tue, 13 Aug 2013 09:01:03 PDT

Benthic invertebrates were sampled at four stations along the Little Bear River continuum: Station 2 in the mountainous headwaters, at Station 4 in the transition area to the lowland valley, at Station 7 below Hyrum Reservoir, and at Station 11 in the low-gradient agricultural area near where the river flows into Cutler Reservoir wetland. At each station samples were collected with sweep nets in each of the habitats, with an effort made to sample each type of habitat in proportion to its abundance. Ethanol-preserved samples were counted utilizing 30X compound microscopes, with 2 or more students providing counts and taxa identifications for the invertebrates from each Station. The invertebrates identified from each station are shown in Table 1. A ratio of the combined counts of clean-water taxa (Ephemeroptera, Plecoptera and Tricoptera) and all other taxa was calculated for each station. This ratio can provide insight on water quality, but with the level of taxonomy used in the class exercise, should be interpreted cautiously.

Anthropogenically Altered Land and its Effect on δ15N Values in Periphyton on a Fourth Order Stream in Utah’s Cache Valley

Chance Broderius — Tue, 13 Aug 2013 09:01:01 PDT

The Little Bear River is a tributary to the Bear River that drains the south end of the Cache Valley in Northern Utah. The upper elevations are more pristine and are made up of mostly forested mountainous terrain with some grazing activity. The lower elevations are comprised of low gradient agricultural and urban parcels. Anthropogenically influenced landscapes can result in higher nitrogen inputs to streams, and these increases are often marked by an increase in the heavy-nitrogen isotope, δ15N. This study looked at the concentration of δ15N in periphyton on the river bed. These concentrations were then compared to anthropogenic land use in the surrounding watershed. δ15N values in the periphyton were significantly correlated with increasing percentages of anthropogenically affected land use in the Little Bear River watershed. It is likely that anthropogenic land uses (manure fertilization and wastewater treatment) caused the enrichment in δ15N concentrations.

Algal Nutrient Limitation throughout the Little Bear River Watershed

Jared Baker — Tue, 13 Aug 2013 09:01:00 PDT

The objective of this study was to use a 5 day bioassay experiment to assess whether nitrogen or phosphorus limited the growth of algae in the Little Bear River watershed. Four sites were sampled along the river in September 2012. The locations of the sites were south of Avon (Station 2), near Paradise, UT (Station 6), downstream of Hyrum Reservoir (Station 7), and downstream of the Waste Water Treatment Facility in Wellsville (Station 10). Chlorophyll a analysis was conducted prior to, after 2.5 days, and at the conclusion of the 5 days. Varying combinations of nitrogen and phosphorus were added to water samples from each site and these were incubated in 125-ml flasks with 150 uM m-2 lighting and at 15°C. ANOVA was used to determine nutrient limitations within samples. Chlorophyll concentrations measured at the conclusion of the experiment indicated that both nitrogen and phosphorus limited algal growth at Stations 2 and 10 while phosphorus alone was limiting at Stations 6 and 7.

Periphyton and Phytoplankton Chlorophyll a Levels in the Little Bear River and Hyrum Reservoir, Utah

Katie Fisher — Tue, 13 Aug 2013 09:00:59 PDT

This study was conducted to assess the applicability of the River Continuum and Serial Discontinuity Concepts to the Little Bear River, using chlorophyll a values along the gradient of the river and within Hyrum Reservoir. Periphyton was analyzed from seven sites and phytoplankton from nine sites (including Hyrum Reservoir) in September 2012. The lower parts of the Little Bear River is heavily influenced by agricultural and anthropogenic sources of nutrients and other pollution, creating poor water quality in its lower reaches. Periphyton levels in the river increased along the gradient, peaking just below Hyrum reservoir, and then decreased with distance downstream. Phytoplankton chlorophyll a concentrations increased significantly with distance downstream, with concentrations near 1.5 μg L-1 in the headwaters and 5 μg L-1 in the slow-moving valley sections. On an aerial basis, chlorophyll in the periphyton community overwhelmingly dominated (>98 percent) the total chlorophyll levels. Within the phytoplankton continuum, there was, however, a drop below Hyrum Reservoir. Furthermore, there was a significant positive relationship between the total phosphorous concentrations and phytoplankton levels. Periphyton levels, however, were not correlated with phosphorus concentrations. The chlorophyll a levels found suggest that high levels of phosphorus contribute to higher levels of algal chlorophyll a. Although these levels were not indicative of poor water quality, mitigation of nutrient sources in the valley would likely create more uniform chlorophyll a levels down the gradient of the LBR.

Anthropogenic Impacts on the Longitudinal Gradient of Nutrients in the Little Bear River

Jason Fuller — Tue, 13 Aug 2013 09:00:57 PDT

I measured the anthropogenic impacts from land use on nutrient concentrations along the Little Bear River in Cache Valley, Utah. Water samples from twelve stations along the Little Bear River were collected and analyzed using an auto analyzer in order to determine conductivity and concentrations of total nitrogen, total phosphorus, soluble reactive phosphorus (SRP), ammonia (NH3), and nitrate (NO3-). Samples were collected at stations thought to reveal anthropogenically influenced nutrient loading. Some of the anthropogenic land usages that potentially impact the nutrient concentrations include agricultural land use, urban land use, Hyrum Reservoir, the Trout of Paradise fishing reserve located near the town of Paradise, and the Wellsville Wastewater Treatment Plant. Specific conductivity measurements indicated a 172 percent increase in ions from the headwaters to the lowest site sampled, near the confluence with Cutler Reservoir. My study indicated that total nitrogen was significantly increased by anthropogenic land use, with nitrate increasing from 115 μg N L-1 in the headwaters to 1260 μg N L-1 in the lowland agricultural areas. Total phosphorus (TP) did not appear to be influenced by anthropogenic land use above Hyrum Reservoir: However, below the reservoir concentrations reached 60-75 μg P L-1, above Utah threshold criteria of 50 μg L-1. Total nitrogen : total phosphorus rations indicated that phosphorus was potentially the limiting nutrient at three of the twelve stations including the Trout of Paradise fishing reserve. The dissolved inorganic nitrogen (DIN): TP ratio indicated that phosphorus was the limiting nutrient at each of the stations except Station 8, which is located below Hyrum Reservoir. These findings highlight the influence of anthropogenic land use on the Little Bear River, within the framework of the Serial Discontinuity Hypothesis (Ward and Stanford, 1995).

Temperature and Discharge on a Highly Altered Stream in Utah's Cache Valley

Andy Pappas — Tue, 13 Aug 2013 09:00:55 PDT

To study the River Continuum Concept (RCC) and the Serial Discontinuity Hypothesis (SDH), I looked at temperature and discharge changes along 52 km of the Little Bear River in Cache Valley, Utah. The Little Bear River is a fourth order stream with one major reservoir, a number of irrigation diversions, and one major tributary, the East Fork of the Little Bear River. Discharge data was collected at six sites on 29 September 2012 and temperature data was collected hourly at eleven sites from 1 October to 20 October 2012. Discharge and temperature both increased as elevation declined to Hyrum Reservoir. After which point, temperature increased slightly and discharge dropped sharply for a period and then returned to similar patterns occurring above the reservoir. In addition to the data collected during our sampling efforts, a long-term temperature dataset available from the Internet was used to observe seasonal temperature changes. While seasonal temperature patterns were variable above the reservoir, the site below Hyrum Reservoir exhibited the strongest increase in temperature from winter lows to summer highs.

A Profile of the Physical Attributes of the Little Bear River in the Context of the Serial Discontinuity Concept

Marc Weston — Tue, 13 Aug 2013 09:00:54 PDT

To study the Little Bear River’s physical characteristics in the context of the serial discontinuity concept, sites were sampled along a continuum from the headwaters to 51 km downstream, near where the Little Bear River flows into Cutler Reservoir. Samples were collected in September 2012 at base flow. To estimate sediment sizes along the transect pebble counts were conducted at six sites and where possible pebble counts were done in both pools and riffles. Sediment sizes showed a decrease in median size (D50 ) of 45 mm at the upper station to the lower station where the substrate was a mixture of sand and silt. An elevation gradient profile measured with ArcGIS demonstrated a significant positive correlation between elevation and substrate size. Sinuosity was measured using ArcGIS and showed an increasing trend from the upper reaches to the lower reaches, but the lower valley agricultural areas had remnants of levees, indicating that the river was not following its natural channel.

Executive Summary : A River Continuum Analysis of an Anthropenically-Impacted System : The Little Bear River, Utah

Nick Heredia — Tue, 13 Aug 2013 09:00:48 PDT

In September 2012 the Aquatic Ecology Practicum class from Utah State University studied the 51km river continuum of the Little Bear River located in northern Utah (Figure 1). The relatively pristine headwaters of the river begin in the Wasatch Mountain Range at an altitude of 1800 m. The river flows northward into Cache Valley where it terminates in Cutler Reservoir (1345 m elevation). Agricultural development and urbanization have modified the natural terrain and chemical characteristics of the river, and Hyrum Reservoir, located midway along the gradient causes a discontinuity in river processes. The results from analyses of stream condition indicators from up to eleven stations along the gradient were interpreted within the context of the River Continuum Concept (Vannote et al. 1980) and the Serial Discontinuity Hypothesis (Ward and Stanford 1983).

A River Continuum Analysis of an Anthropogenically-Impacted System: The Little Bear River, Utah

Wayne A. Wurtsbaugh et al. — Tue, 13 Aug 2013 09:00:47 PDT

Field Trip Overview: Habitat Loss and Plant Invasions in Northern Utah

Justin R. Williams et al. — Fri, 16 Dec 2011 08:28:55 PST

Selection and Vegetative Propagation of Native Woody Plants for Water-Wise Landscaping

Larry A. Rupp et al. — Fri, 16 Dec 2011 08:28:54 PST

Native woody plants with ornamental characteristics such as brilliant fall color, dwarf form, or glossy leaves have potential for use in water conserving urban landscapes. Individual accessions with one or more of these unique characteristics were identified based on the recommendations of a wide range of plant enthusiasts (both professional and amateur). Documentation of these accessions has been done through locating plants on-site where possible and then developing a record based on digital photography, GPS determined latitude and longitude, and place marking of Google Earth© images. Since desirable characteristics are often unique to a single plant, utilization of these plants by the landscape industry requires that they be clonally propagated. Methods of asexual propagation including grafting, budding, layering and cuttings may be successful with native plants, but are species and even accession specific. We report on the successful cutting propagation of Arctostaphylos patula, A. pungens, and Cercocarpus intricatus, and lack of success with Juniperus osteosperma, and Mahonia fremontii.

Trend of Gardner Saltbush and Halogeton in the Lower Green River Basin, Wyoming

Sherel Goodrich et al. — Fri, 16 Dec 2011 08:28:54 PST

Displacement of Gardner saltbush (Atriplex gardneri) by halogeton (Halogeton glomeratus) is being recorded at several points in the Lower Green River Basin, Wyoming by line intercept measurements and by repeat photography. This paper gives results of the monitoring studies as of 2009. Total displacement of Gardner saltbush by halogeton has taken as little as 10 years at some locations. Loss of Gardner saltbush to halogeton has major management implications.

Seasonal Soil CO2 Flux Under Big Sagebrush (Artemisia tridentata Nutt.)

Michael C. Amacher et al. — Fri, 16 Dec 2011 08:28:53 PST

Soil respiration is a major contributor to atmospheric CO2, but accurate landscape-scale estimates of soil CO2 flux for many ecosystems including shrublands have yet to be established. We began a project to measure, with high spatial and temporal resolution, soil CO2 flux in a stand (11 x 25 m area) of big sagebrush (Artemisia tridentata Nutt.) at the Logan, Utah, Forestry Sciences Laboratory. Beginning on Nov. 1, 2009, hourly soil CO2 flux measurements were made at a single location in the stand using the Li-Cor LI-8100 soil CO2 flux instrument and 20-cm long-term chamber. Beginning in April, 2010, monthly soil CO2 flux measurements were made on a grid of 11 locations within the stand using the LI- 8100 equipped with the 20-cm survey chamber. Hourly soil temperature (10-cm depth) and volumetric soil water content data were also collected. Soil CO2 flux, temperature, and water content were highly temporally and spatially variable in the sagebrush stand. Mean (std dev) soil CO2 flux, temperature, and water content for the measurement period (November 1, 2009 - October 31, 2010) were 0.96 (0.81) umol m-2 s-1, 10.59 (10.11) deg C, and 0.101 (0.062) m3 m-3, respectively. Calculated annual soil CO2 flux obtained by summing all the hourly measurements was 328 g C m-2 y-1. For semi-arid or arid sites where precipitation is less than evapotranspiration, measured total annual soil CO2 flux will be less than the potential maximum because of dry season suppression of soil respiration when soil water content is very low.

GIS Ordination Approach to Model Distribution of Shrub Species in Northern Utah

Samuel Rivera et al. — Fri, 16 Dec 2011 08:28:52 PST

Anthropogenic and natural disturbances represent a serious threat to natural ecosystems dominated by big sagebrush (Artemisia tridentata). Conservation efforts aim to restore original species composition and prevent the invasion of undesirable species. In order to restore the historic plant communities, we need a clear understanding of how species compositions are distributed along environmental gradients. Species ordination is a process of placing plant species along environmental gradients. This study was conducted in Rich County, Utah, where substantial changes in species composition have been documented in recent years. Field data, literature review, multivariate analyzes, GIS and remote sensing techniques, and expert knowledge were used to define environmental variables and their respective suitability ranges of where shrub species may occur along this area. Ordination and CART- statistical analyzes were used to estimate and predict suitability of shrub species along environmental gradients. GIS procedures were used to spatially predict species distribution. Field data and the Southwest Regional Gap Analysis Project data provided useful information to build the model and 20 percent of field data was withheld to cross-validate the findings. Final results showed that the shrub species distribution in the rangelands of Northern Utah, specifically Rich County, might be driven by precipitation and temperature gradients -influenced greatly by elevation. Slope contributing area, NDVI, and solar radiation were statistically significant factors explaining shrub distribution. To our perception, soil moisture availability might be the most explanatory variable behind these findings. In the model validation, the Kappa coefficient was K = 61.3 percent and the overall model accuracy was 74 percent. The location of species distribution areas, in the final map, can be useful to managers in order to define where resources might be allocated to preserve and restore these native rangeland ecosystems.

Introducing Big Sagebrush into a Crested Wheatgrass Monoculture

Robert L. Newhall et al. — Fri, 16 Dec 2011 08:28:52 PST

Crested wheatgrass (Agropyron desertorum or A. cristatum) has been effectively used to stabilize arid and semi-arid range sites for decades. Reestablishing native plant materials into these areas is often desirable to increase wildlife habitat and ecological diversity. Due to its competitive nature, efforts to reestablish native plants into crested wheatgrass monocultures have had limited success. Tillage will control the grass but leaves the soil vulnerable to erosion and weed invasion. This publication will report on a trial conducted near Nephi, Utah to find a method of introducing native plants into a crested wheatgrass monoculture without subjecting the resource base to degradation in the conversion process. In this trial, the effect of chemically controlling crested wheatgrass before transplanting big sagebrush (Artemisia tridentata) was studied. Small container grown plants of sagebrush were transplanted either directly into a 60 year-old stand of crested wheatgrass or after chemically controlling the grass. Three different subspecies of big sagebrush; Basin big sagebrush (Artemisia tridentata Nutt. ssp. tridentata), Mountain big sagebrush (Artemisia tridentata Nutt. ssp. vaseyana (Rydb.) Beetle) and Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young); were planted to see if there would be differences among subspecies. Four years of data indicate that controlling crested wheatgrass prior to transplanting resulted in higher sagebrush survival and faster establishment. There were some differences among sagebrush subspecies. Basin big sagebrush survived equally well with or without grass control but grew faster with grass control. Chemical control of the grass was important for both the survival and growth of Mountain big sage and Wyoming big sage.

Range Management in the Face of Climate Change

James C. Catlin et al. — Fri, 16 Dec 2011 08:28:51 PST

Moderating Livestock Grazing Effects on Plant Productivity, Nitrogen and Carbon Storage

John Carter et al. — Fri, 16 Dec 2011 08:28:50 PST

Multi-year studies of plant communities and soils in the Bear River Range in southeastern Idaho and northeastern Utah found reduced ground cover and herbaceous production in areas grazed by livestock when compared to reference values or long-term rested areas. Reductions in these ecosystem components have lead to accelerated erosion and losses in stored carbon and nitrogen. Restoration of these ecosystem components, with their associated carbon and nitrogen storage, is possible by application of science-based grazing management.

Bottom-up Effects of Substrate on Two Adjacent Shrub Communities and the Distribution of a Rare and Endangered Plant Species, Astragalus jaegerianus Munz.

Barry A. Prigge et al. — Fri, 16 Dec 2011 08:28:49 PST

Edaphic habitats are botanically interesting because of differences in vegetation with neighboring sites and because they tend to harbor rare species. In the central Mojave Desert, there are granite colluvial substrates where creosote bush, the dominant shrub in the area, is sparser and generally smaller than in the neighboring creosote bush communities. It is on these sites that the Lane Mountain milkvetch, a rare and federally endangered species, is restricted. The milkvetch is a nitrogen-fixer and grows under and within the canopy of host shrubs. Our previous studies have demonstrated that the milkvetch has no preference for species of host shrub, except Larrea tridentata, which appears to be an unsuitable host plant for the milkvetch. In this study, we surveyed three transects within milkvetch habitats and three transects in adjacent creosote bush habitats in the year 2000 and again in 2010, a period coincident with long-term drought conditions in the Mojave Desert. Our results show that adjacent milkvetch and creosote bush shrub communities differ significantly in shrub height, shrub volume, and shrub density in the year 2000: the shrubs in milkvetch communities were more numerous but smaller compared to adjacent creosote bush scrub. Species richness also differed between communities in the year 2000: milkvetch communities contained 19 different shrub species and creosote bush communities had only 9 species. Surveys in 2010 show that the drought had significant negative effects on both shrub communities. Total shrub mortality (166 shrubs) was high compared to shrub recruitment (16 shrubs), and the majority of mortality and recruitment occurred in milkvetch communities (131 deaths and 16 recruits). Shrub densities decreased significantly in milkvetch communities in 2010, but were still considerably higher than in creosote bush communities. These results suggest that the restricted distribution of the Lane Mountain milkvetch may be the result of higher shrub densities in milkvetch shrub communities; increased shrub densities increases the proximity of suitable host shrubs, which in turn increase the probability of successful seed dispersal and establishment.

Synergistic Monitoring – Addressing the Threats and Identifying Opportunities

John C. Swanson et al. — Fri, 16 Dec 2011 08:28:49 PST

For many years, land managers and scientists have been applying a variety of land treatments to improve or protect rangeland ecosystems. Collectively, we have studied the response of these treatments and wildfire events to identify opportunities for maintaining or improving Nevada sagebrush ecosystem health and functionality. In partnership with collaborators, we initiated a State-wide effort to capture, consolidate, and summarize implementation, monitoring, and research information for these events. We are conducting field studies to identify and fill information gaps. We seek a new and expanded information base that is available to Nevada land managers, scientists, and others interested in healthy and resilient sagebrush sites. We plan to identify the consequences of passive and active management; develop predictive tools for adaptive management; identify research needs; and increase accessibility to location, implementation and monitoring information for these events. Through the collaborative integration of our field study results with historic and current research and monitoring information, we seek to increase knowledge of landscape-level and site-specific ecological processes. This will further develop our ability to manage and predict rangeland health, integrity, resilience (after disturbance), and resistance (to undesired change under significant disturbance regimes) in the context of multiple-use management.