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Environmental Sciences

Utah State University

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Articles 181 - 210 of 868

Full-Text Articles in Life Sciences

Comparison Of Water Dynamics In Aspen And Conifer: Implications For Ecology Water Yield Augmentation, Eric Martin Lamalfa May 2007

Comparison Of Water Dynamics In Aspen And Conifer: Implications For Ecology Water Yield Augmentation, Eric Martin Lamalfa

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Differences in water dynamics between deciduous aspen (Populus tremuloides) and co-occurring evergreen conifer species in the Northern Rocky Mountains result from complex physical and biological interactions. A comprehensive evaluation of individual water transfer mechanisms was used to elucidate the relative importance of several components of the hydro logic cycles of aspen and conifer, and determine which water transfer mechanisms have potential to cause differences in net water yield.

Adjacent aspen and conifer stands were monitored to determine snow accumulation and ablation (snow survey), soil moisture recharge (capacitance probes), snowpack sublimation (sublimation pan), transpiration period (thermal dissipation probes), and …


Relative Role Of Understory And Overstory In Carbon And Nitrogen Cycling In A Southern Appalachian Spruce-Fir Forest, P. T. Moore, H. Van Miegroet, N. S. Nicholas Jan 2007

Relative Role Of Understory And Overstory In Carbon And Nitrogen Cycling In A Southern Appalachian Spruce-Fir Forest, P. T. Moore, H. Van Miegroet, N. S. Nicholas

Watershed Sciences Faculty Publications

This study investigated aboveground pools and fluxes of biomass, carbon (C), and nitrogen (N) in the overstory and understory of a southern Appalachian red spruce (Picea rubens Sarg.) – Fraser fir (Abies fraseri (Pursh) Poir.) forest, following adelgid-induced fir mortality and spruce windthrow. Using fifty 20 m × 20 m plots, stratified by elevation (1700–1900 m), we estimated standing biomass and fluxes of all growth forms from periodic stand inventories (1998–2003), vegetation surveys, and existing or derived allometric equations. Total C and N pools and fluxes were calculated from plant- and tissue-specific C and N concentrations. Total aboveground biomass attained …


Soil Organic Carbon Dynamics Along A Climatic Gradient In A Southern Appalachian Spruce-Fir Forest, C. E. Tewksbury, H. Van Miegroet Jan 2007

Soil Organic Carbon Dynamics Along A Climatic Gradient In A Southern Appalachian Spruce-Fir Forest, C. E. Tewksbury, H. Van Miegroet

Watershed Sciences Faculty Publications

A field study was conducted in a high-elevation spruce–fir (Picea rubens Sarg. – Abies fraseri (Pursh.) Poir) forest in the Great Smoky Mountains National Park to assess the effect of temperature on soil C storage and dynamics. In eight plots along an elevation gradient (1500–1900 m), we measured soil temperature, forest floor and mineral soil C, litter decomposition, soil respiration, and forest floor mean residence time. Mean annual soil temperature and annual degree-days above 5 °C were inversely correlated with elevation. Total soil C (166–241 Mg·ha–1) showed no trend with elevation, while forest floor C accumulation (16.3–35.9 Mg·ha–1) decreased significantly …


From Herd Diversification To Livelihood Diversification As A Response To Poverty: The Case Of The Waso Boran Of Northern Kenya, D. Layne Coppock, Abdullahi D. Jillo, Abdillahi A. Aboud Dec 2006

From Herd Diversification To Livelihood Diversification As A Response To Poverty: The Case Of The Waso Boran Of Northern Kenya, D. Layne Coppock, Abdullahi D. Jillo, Abdillahi A. Aboud

Environment and Society Faculty Publications

The Waso Boran of northern Kenya used to have large, mobile, and diverse herds of livestock that exploited equally large and diverse rangelands. Forty years of human population growth, drought, environmental change, and lack of relevant policies have altered this situation, however, with the majority of Waso Boran today being livestock poor and engaged in a variety of non-pastoral activities to diversify their livelihoods. One-third of 540 households we surveyed in Isiolo District now have ten head of cattle or less, and a larger census suggests that only 15 percent of households can currently be categorized as mobile pastoralists. The …


Community Perceptions Concerning Key Ecological Resources At Risk In Baringo District, Kenya, D. Layne Coppock, Mark N. Mutinda, Abdillahi A. Aboud Dec 2006

Community Perceptions Concerning Key Ecological Resources At Risk In Baringo District, Kenya, D. Layne Coppock, Mark N. Mutinda, Abdillahi A. Aboud

Environment and Society Faculty Publications

Key ecological resources in arid and semi-arid lands are often characterized by small patches of seasonal grazing and important water points that lend critical support to entire production systems. When key resources are degraded or lost, production systems can be badly compromised. The Baringo District of north-central Kenya is well known for enduring decades of environmental degradation and food relief. As an initial part of an effort to map and characterize key ecological resources at risk in Baringo, we interviewed 136 resident leaders from pastoral and agro-pastoral areas. We asked them to identify and rank their most vulnerable ecological resources, …


Collective Action By Women’S Groups To Combat Drought And Poverty In Northern Kenya, D. Layne Coppock, Solomon Desta, Getachew Gebru, Adan Wako, Ibrahim Aden, Chachu Tadecha, Seyoum Tezera Dec 2006

Collective Action By Women’S Groups To Combat Drought And Poverty In Northern Kenya, D. Layne Coppock, Solomon Desta, Getachew Gebru, Adan Wako, Ibrahim Aden, Chachu Tadecha, Seyoum Tezera

Environment and Society Faculty Publications

Collective action can be an effective means of local development and risk reduction among rural people, but few examples have been documented in pastoral areas. We conducted extensive interviews for 16 women’s groups residing in northern Kenya. Our objectives were to understand how groups were formed, governed, and sustained and what activities they have pursued. The groups we interviewed were 10 years old, on average. Charter memberships averaged about 24 women, 20 of whom were illiterate. Half of the groups formed after facilitation by a development partner and half formed spontaneously. Groups are governed under detailed constitutional frameworks with elected …


Public Engagement To Prioritize The Pastoral Research Agenda At The Pastoral And Agro-Pastoral Research Center Of Oari In Ethiopia, D. Layne Coppock, Getachew Gebru, Lemma Gizachew, Sintayehu Mesele, Mohammed Hassena, Solomon Desta Dec 2006

Public Engagement To Prioritize The Pastoral Research Agenda At The Pastoral And Agro-Pastoral Research Center Of Oari In Ethiopia, D. Layne Coppock, Getachew Gebru, Lemma Gizachew, Sintayehu Mesele, Mohammed Hassena, Solomon Desta

Environment and Society Faculty Publications

The Oromia Agricultural Research Institute (OARI) has a mandate to conduct agricultural and livestock research throughout the Regional State of Oromia in Ethiopia. OARI has recently opened a facility near Yabello town on the Borana Plateau called the Pastoral and Agro-Pastoral Research Center. A meeting was held in August 2006 at Yabello that involved representatives from pastoral communities, the private sector, government, and non-governmental organizations. The aim was to engage stakeholders in a process of problem prioritization and set the stage to create new partnerships to better address pressing problems. The final priorities included: addressing a general decline in forage …


Changes In Land Cover And Soil Conditions For The Yabelo District Of The Borana Plateau, 1973-2003, D. Layne Coppock, Sintayehu Mesele, Heluf Gebrekidan, Lemma Gizachew Dec 2006

Changes In Land Cover And Soil Conditions For The Yabelo District Of The Borana Plateau, 1973-2003, D. Layne Coppock, Sintayehu Mesele, Heluf Gebrekidan, Lemma Gizachew

Environment and Society Faculty Publications

It has been proposed that the Borana Plateau has markedly changed in terms of land cover and land use in recent decades, but no hard data have been available to critically assess this claim. In addition, systematic analysis of soil properties has been limited. Research was designed to measure changes in land cover/land use over 30 years in the 400-km2 Yabelo District of southern Ethiopia using three satellite images taken at an average interval of 15 years. Samples were also collected to assess variation in the physical and chemical properties of dominant soils. Results indicated that Yabelo District has indeed …


Remapping The Cliff Chipmunk (Neotamias Dorsalis) Distribution And Creating A Habitat Association Model In Southern Idaho, Masako Niwa May 2006

Remapping The Cliff Chipmunk (Neotamias Dorsalis) Distribution And Creating A Habitat Association Model In Southern Idaho, Masako Niwa

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The distribution of the cliff chipmunk in Idaho was previously considered to include only the Raft River Valley and the Goose Creek Basin. A pilot study was conducted in 2003 and 2004. Thirty-five cliff chipmunk presence locations and 124 absence locations were recorded. Habitat variables of elevation, slope, deviation from south, distance to water, and vegetation type were extracted for all of the absence and presence points by means of GIS analysis. The data were analyzed by implementing a classification tree, and a "GIS habitat association model" was created. The model was tested in 2005, and the overall model accuracy …


Terpenes And Carbohydrate Source Influence Rumen Fermentation, Digestibility, Intake, And Preference In Sheep, J. J. Villalba, F. D. Provenza, K. C. Olson Jan 2006

Terpenes And Carbohydrate Source Influence Rumen Fermentation, Digestibility, Intake, And Preference In Sheep, J. J. Villalba, F. D. Provenza, K. C. Olson

Green Canyon Environmental Research Area, Logan Utah

We hypothesized that toxins and nutrients in foods interact to influence foraging behavior by herbivores. Based on this hypothesis we predicted that 1) terpenes in big sagebrush (Artemisia tridentata) influence intake and preference in sheep for diets varying in sources of nonstructural (barley grain) and structural (sugar beet pulp) carbohydrates, and 2) these effects are due to the differential effects of terpenes on fermentation products and apparent digestibility of each class of carbohydrates. Lambs were fed 2 isoenergetic and isonitrogenous diets with varying proportions of the same ingredients (beet pulp- and barley grain-based diet) or offered a choice between the …


Spatial Analyses Of Trophic Linkages Between Basins In The Great Salt Lake, Wayne A. Wurtsbaugh, David Naftz, Shane Bradt Jan 2006

Spatial Analyses Of Trophic Linkages Between Basins In The Great Salt Lake, Wayne A. Wurtsbaugh, David Naftz, Shane Bradt

Watershed Sciences Faculty Publications

Although the Great Salt Lake is frequently treated as if it were a single body of water, the natural bays and transportation causeways have divided it into a system of four bays. The bays, however, do not function independently because water, nutrients and other contaminants flow between them. The purpose of our study was to analyze the water quality in three of the bays (Farmington, Bear River and Gilbert), to determine fluxes of nutrients between them, and to determine how this was influencing brine shrimp populations in the lake. Discharge and nutrient concentrations were measured at constrictions separating the three …


Salinity Controls Phytoplankton Response To Nutrient Enrichment In The Great Salt Lake, Utah, Usa, Amy M. Marcarelli, Wayne A. Wurtsbaugh, O. Griset Jan 2006

Salinity Controls Phytoplankton Response To Nutrient Enrichment In The Great Salt Lake, Utah, Usa, Amy M. Marcarelli, Wayne A. Wurtsbaugh, O. Griset

Watershed Sciences Faculty Publications

To examine how salinity and nutrient supply interact to control phytoplankton community composition, nutrient limitation, and dinitrogen (N2) fixation rates in the Great Salt Lake (Utah, USA), we conducted a series of bioassay experiments with plankton from both Gilbert Bay, where salinities are near 160 g·L–1, and Farmington Bay, where salinities range from 10 to 90 g·L–1. Six-day nutrient addition bioassay experiments showed that the extant phyto plankton communities in both bays were limited by nitrogen (N). However, in 28- to 30-day factorial bioassay experiments in which both salinities and nutrient supply were manipulated, phosphorus stimulated chlorophyll a as much …


Degree Of Sedentarization Affects Risks And Conflicts For The Waso Boran In Northern Kenya, D. Layne Coppock, Abdullahi D. Jillo, Mark N. Mutinda, Abdilla A. Aboud Dec 2005

Degree Of Sedentarization Affects Risks And Conflicts For The Waso Boran In Northern Kenya, D. Layne Coppock, Abdullahi D. Jillo, Mark N. Mutinda, Abdilla A. Aboud

Environment and Society Faculty Publications

The Waso Borana have lived for over a century in northern Kenya. In the last few decades, however, their ability to maintain their traditions has been severely challenged. Here we report survey results from 540 households in Isiolo District, stratified among three groups differing in terms of lifestyle: sedentary, semi-sedentary, and mobile. In some cases these groups vary with respect to important perceived risks, causes of natural-resource related conflict, and possible solutions to conflict. For example, sedentary respondents often noted concerns over land tenure problems, human diseases, and political incitement. Mobile respondents, in contrast, often noted primary concerns over drought, …


Agro-Pastoralists’ Wrath For The Prosopis Tree: The Case Of The Il Chamus Of Baringo District, Kenya, D. Layne Coppock, Abdillahi A. Aboud, Phillip K. Kisoyan Dec 2005

Agro-Pastoralists’ Wrath For The Prosopis Tree: The Case Of The Il Chamus Of Baringo District, Kenya, D. Layne Coppock, Abdillahi A. Aboud, Phillip K. Kisoyan

Environment and Society Faculty Publications

Indigenous to Peru, Chile, and Argentina, the woody plant called Prosopis juliflora (also known by the American common name of “Honey Mesquite”) has spread world-wide in recent decades, including rangelands throughout Latin America, North America, south and central Asia, Australia, and sub-Saharan Africa. A species known for rapid establishment, high adaptability, and fast rates of growth, its dispersal has primarily been a consequence of intentional introduction by well- meaning “technical experts” who wanted to provide a new source of fodder, fuel wood, or a means to combat desertification in arid and semi-arid lands. One problem, however, is that unless Prosopis …


Linking Pastoralists And Exporters In A Livestock Marketing Chain: Recent Experiences From Ethiopia, D. Layne Coppock, Solomon Desta, Getachew Gebru, Seyoum Tezera Dec 2005

Linking Pastoralists And Exporters In A Livestock Marketing Chain: Recent Experiences From Ethiopia, D. Layne Coppock, Solomon Desta, Getachew Gebru, Seyoum Tezera

Environment and Society Faculty Publications

The Boran of southern Ethiopia have been traditionally viewed as unwilling or unable to engage in large scale, commercialized livestock trade. Here we report on the creation of a new livestock marketing chain from the Borana Plateau to export outlets largely serving the Gulf States. Since 2003 various meetings and exchange tours were organized by collaborating agencies and PARIMA to directly link pastoral producers with livestock exporters and policy makers. This occurred against a backdrop of growing export demand for small ruminants, rapid development of private export industry, formation of well-trained pastoral marketing groups (often dominated by women), and provision …


Energy Efficient Appliances, Leona Hawks, Celia Peterson Jul 2005

Energy Efficient Appliances, Leona Hawks, Celia Peterson

All Current Publications

No abstract provided.


Energy Efficient Windows, Leona Hawks, Celia Peterson Jul 2005

Energy Efficient Windows, Leona Hawks, Celia Peterson

All Current Publications

No abstract provided.


Checklist To Determine Energy Efficiency Of A Home, Leona Hawks Jul 2005

Checklist To Determine Energy Efficiency Of A Home, Leona Hawks

All Current Publications

No abstract provided.


Insulating Concrete Forms (Icfs), Leona Hawks, Koa Percer Jul 2005

Insulating Concrete Forms (Icfs), Leona Hawks, Koa Percer

All Current Publications

No abstract provided.


Lighting, Leona Hawks, Celia Peterson Jul 2005

Lighting, Leona Hawks, Celia Peterson

All Current Publications

No abstract provided.


Photovoltaic Systems (Pv), Leona Hawks, Celia Peterson Jul 2005

Photovoltaic Systems (Pv), Leona Hawks, Celia Peterson

All Current Publications

No abstract provided.


Solar South, Roof Overhangs, And Light Shelves, Leona Hawks, Celia Peterson Jul 2005

Solar South, Roof Overhangs, And Light Shelves, Leona Hawks, Celia Peterson

All Current Publications

No abstract provided.


Continuing Analysis Of Phytoplankton Nutrient Limitation In Farmington Bay And The Great Salt Lake, Wayne A. Wurtsbaugh, Amy M. Marcarelli Apr 2005

Continuing Analysis Of Phytoplankton Nutrient Limitation In Farmington Bay And The Great Salt Lake, Wayne A. Wurtsbaugh, Amy M. Marcarelli

Watershed Sciences Faculty Publications

Farmington Bay is a nutrient-enriched, highly eutrophic embayment of the Great Salt Lake. The highly variable salinity of the bay influences what species of plankton can survive there. Previous analyses suggested that cyanobacteria (blue-green algae) may not be able to survive or fix atmospheric nitrogen at high salinities, thus maintaining the lake in a nitrogen-limited state. To determine the interacting influence of nutrients and salinity on the growth and nitrogen fixation of plankton we performed a 28-day bioassay with water from Farmington and Gilbert Bays in October 2004. We tested the response of the plankton to additions of nitrogen (N) …


Ecological Analysis Of Nutrient, Plankton And Benthic Communities In Farmington Bay And The Great Salt Lake, Utah (2004), Amy M. Marcarelli, Wayne A. Wurtsbaugh Feb 2005

Ecological Analysis Of Nutrient, Plankton And Benthic Communities In Farmington Bay And The Great Salt Lake, Utah (2004), Amy M. Marcarelli, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

In Fall 2004, the Aquatic Ecology Practicum class at Utah State University finished a third year of research on limnological and ecological characteristics of Farmington Bay and Gilbert Bays of the Great Salt Lake. Our previous research has produced interesting findings in Farmington Bay, including hypereutrophy (Marcarelli et a!. 2001), high phosphorus loading into the Bay, overnight water column anoxia linked to high winds (Wurtsbaugh et a!. 2002), potential predator control of brine shrimp, and high levels of hydrogen sulfide in the sediment and deep brine layer (Marcarelli et a!. 2003). These class findings have lead to increased interest in …


Landscape Patterns Of Streams & Lakes In Montane Watersheds Determine Water Temperatures & Nutrient Transport: Watershed Analyses And N Tracer Experiments, Wayne A. Wurtsbaugh, J. Garrett, G. Burkart, W. Fleenor, K. Nydick, R. Hall, Michelle A. Baker Jan 2005

Landscape Patterns Of Streams & Lakes In Montane Watersheds Determine Water Temperatures & Nutrient Transport: Watershed Analyses And N Tracer Experiments, Wayne A. Wurtsbaugh, J. Garrett, G. Burkart, W. Fleenor, K. Nydick, R. Hall, Michelle A. Baker

Watershed Sciences Faculty Publications

In glaciated mountains, lakes are interspersed through watersheds and connected by streams. Although lakes or streams are frequently studied as individual water bodies, studying them as integrated functional units provides considerable insight on temperature patterns, nutrient transport and other functions. In the Sawtooth Mountains (Idaho), inter-lake distance averages 2.8 km. In summer, lakes are solar collectors, and warm outflow streams as much as 10 C, thus increasing metabolic rates. These streams seldom cool to equilibrium temperatures before encountering another lake, where the waters tend to overflow and mix into the epilimnion. With overflow, N-15 tracer experiments demonstrated that water and …


Pastoral Risk Management In Southern Ethiopia: Observations From Pilot Projects Based On Participatory Community Assessments, D. Layne Coppock, Solomon Desta, Seyoum Tezera, Rancis K. Lelo Aug 2004

Pastoral Risk Management In Southern Ethiopia: Observations From Pilot Projects Based On Participatory Community Assessments, D. Layne Coppock, Solomon Desta, Seyoum Tezera, Rancis K. Lelo

Environment and Society Faculty Publications

The Borana pastoral system has come under increasing pressure as human populations grow and per capita availability of resources declines. Livestock exhibit large, periodic die-offs that threaten wealth accumulation and food security. Several types of interventions may improve risk management here. For example, there may be opportunity for some pastoralists to diversify their livelihoods. Here we report on a community-based process involving pilot projects begun since 2000. We have embraced Participatory Rural Appraisal (PRA) and Action Research (AR) as tools for investigation and empowerment of local people. Full PRAs were conducted for semi-settled communities, located near towns, to identify priority …


Analysis Of Phytoplankton Nutrient Limitation In Farmington Bay And The Great Salt Lake, Wayne A. Wurtsbaugh, Amy M. Marcarelli Jun 2004

Analysis Of Phytoplankton Nutrient Limitation In Farmington Bay And The Great Salt Lake, Wayne A. Wurtsbaugh, Amy M. Marcarelli

Watershed Sciences Faculty Publications

The Great Salt Lake is bordered to the south and east by a growing metropolitan area that contributes high nutrients to Farmington Bay. This large bay is eutrophic, and there is concern that continued increases in effluents from the Salt Lake City area could extend to impact the much larger, and currently less productive, Gilbert Bay. This study focused on determining how nutrient supplies might limit, and therefore control, algal populations in Farmington Bay and Gilbert Bay at different salinities. We tested both short and long-term responses of algal growth using laboratory nutrient addition bioassays in the summer and fall …


Quantifying Losses Of Understory Forage In Aspen Stands On The Dixie And Fishlake National Forests, Barton R. Stam May 2004

Quantifying Losses Of Understory Forage In Aspen Stands On The Dixie And Fishlake National Forests, Barton R. Stam

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The West has lost up to 60% of its historic aspen stands over the last century, probably as a result of the successional tendency of aspen to be replaced by coniferous species in the absence of periodic fires. One of several major impacts of this change is the loss of understory forage as conifer canopy cover increases. I measured understory biomass in aspen stands ranging from 0% to 81 % absolute conifer cover in the canopy and found that understory production declines exponentially as conifers replace aspen. I also did an economic analysis to determine the value of the forage …


Response Of A Peatland Ecosystem To Stratospheric Ozone Reduction In Tierra Del Fuego, Thomas Matthew Robson May 2004

Response Of A Peatland Ecosystem To Stratospheric Ozone Reduction In Tierra Del Fuego, Thomas Matthew Robson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Tierra del Fuego, at the southernmost tip of South America, is influenced by ozone depletion. The landscape of southern and western Tierra de! Fuego is dominated by peatlands; they are important locally and in the context of global climate change, because they store large quantities of organic carbon.

To determine the influence of solar ultraviolet-B radiation (UV-B) on a Tierra de! Fuego peatland, we selectively filtered solar UV-Bin ten pairs of plots. Polyfluorine filters were used to create the Near-Ambient-UV-B Treatment (90% solar UV-B), and polyester filters to create the Reduced-UV-B Treatment ( 17% solar UV-B). These filters were first …


Hydrogen Sulfide In Farmington Bay And The Great Salt Lake: A Potential Odor-Causing Agent, Wayne A. Wurtsbaugh, Amy M. Marcarelli Mar 2004

Hydrogen Sulfide In Farmington Bay And The Great Salt Lake: A Potential Odor-Causing Agent, Wayne A. Wurtsbaugh, Amy M. Marcarelli

Watershed Sciences Faculty Publications

Odors from Farmington Bay and/or the Great Salt Lake frequently impact residents of Salt Lake and Davis counties, but the agent causing the problem and the origin of the odor is uncertain. Hydrogen sulfide (H2S) gas is produced in the deeper layers of water in Farmington Bay and Gilbert Bay in the Great Salt Lake, but these deeper waters are generally part of high salinity deep-brine layers that are resistant to wind mixing. Hydrogen sulfide has a "rotten-egg" odor and is a likely component contributing to the "lake stink." The goals of this study were to determine (1) whether wind …