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2017

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Articles 241 - 270 of 428

Full-Text Articles in Natural Resources and Conservation

Competition Amplifies Drought Stress In Forests Across Broad Climatic And Compositional Gradients, Kelly E. Gleason, John B. Bradford, Alessandra Bottero, Anthony W. D'Amato, Shawn Fraver, Brian J. Palik, Michael A. Battaglia, Louis Iverson, Laura Kenefic, Christel C. Kern May 2017

Competition Amplifies Drought Stress In Forests Across Broad Climatic And Compositional Gradients, Kelly E. Gleason, John B. Bradford, Alessandra Bottero, Anthony W. D'Amato, Shawn Fraver, Brian J. Palik, Michael A. Battaglia, Louis Iverson, Laura Kenefic, Christel C. Kern

Environmental Science and Management Faculty Publications and Presentations

Forests around the world are experiencing increasingly severe droughts and elevated competitive intensity due to increased tree density. However, the influence of interactions between drought and competition on forest growth remains poorly understood. Using a unique dataset of stand-scale dendrochronology sampled from 6405 trees, we quantified how annual growth of entire tree populations responds to drought and competition in eight, long-term (multi-decadal), experiments with replicated levels of density (e.g., competitive intensity) arrayed across a broad climatic and compositional gradient. Forest growth (cumulative individual tree growth within a stand) declined during drought, especially during more severe drought in drier climates. Forest …


Land Use As An Indicator Of Stream Habitat Quality In Salt Creek, Adam Brown May 2017

Land Use As An Indicator Of Stream Habitat Quality In Salt Creek, Adam Brown

Department of Environmental Studies: Undergraduate Student Theses

This study sought to quantify land use types in Lancaster County and identify which, if any, environmental parameters were significantly influencing fish and invertebrate distribution in the Salt Creek basin. Historical sampling data were obtained from the Nebraska Department of Environmental Quality. Watershed land cover maps were created and the percentages of urban/developed, forested, row crop, and grassland use were calculated. This data was combined with NDEQ water quality parameter, fish, and invertebrate sampling data to conduct nonmetric multidimensional scaling. This analysis did not provide significant conclusions about the driving force of fish and invertebrate distribution in this region because …


Influence Of Stream Permanence, Predation, And Invasive Species On Crayfish In The Ozark Highlands With An Emphasis On Species Of Greatest Conservation Need (Orconectes Marchandi, Orconectes Eupunctus And Cambarus Hubbsi), Allyson Noelle Yarra May 2017

Influence Of Stream Permanence, Predation, And Invasive Species On Crayfish In The Ozark Highlands With An Emphasis On Species Of Greatest Conservation Need (Orconectes Marchandi, Orconectes Eupunctus And Cambarus Hubbsi), Allyson Noelle Yarra

Graduate Theses and Dissertations

Due to the ecological importance of crayfish and the increasing vulnerability of freshwater systems due to habitat loss, invasive species, and hydrologic alteration, understanding crayfish-environment relationships is crucial in the context of aquatic species conservation. I sought to examine the influence of hydrologic variation among intermittent and permanent streams on crayfish occupancy, abundance, predation risk, and potential vulnerability to invasive species effects. I conducted crayfish and environmental data sampling during two consecutive summers across 20 Ozark streams of differing permanence levels (10 intermittent, 10 permanent). In these same streams, I conducted fish and scat surveys over the course of four …


Ecological Importance Of Invader Source Population And Disturbance In Aquatic Invasions, Nicole Elizabeth Graham May 2017

Ecological Importance Of Invader Source Population And Disturbance In Aquatic Invasions, Nicole Elizabeth Graham

Graduate Theses and Dissertations

Invasive species are a global problem and their effects on recipient ecosystems may be mediated by disturbance and intraspecific variation. Crayfish can substantially influence stream structure and function, and invasive crayfish often have differential impacts than native crayfish in aquatic ecosystems. Since species traits often vary across a distribution, it is possible that invasive crayfish from different source populations may have distinct impacts on recipient ecosystem structure and function. In the Ozark Highlands of Arkansas and Missouri, USA, invasive O. neglectus (the Ringed Crayfish) may be leading to the displacement of native O. eupunctus (the Coldwater Crayfish). The objective of …


Impacts On The Stakeholders Of The Nexus Pipeline, Jessica A. Speweike May 2017

Impacts On The Stakeholders Of The Nexus Pipeline, Jessica A. Speweike

Honors Projects

This journalistic feature covers the different impacts on those individuals who are involved with or affected by the Nexus Gas Transmission pipeline. Testimony from Ohio landowners, activists, scientists and public officials cover a variety of opinions and concerns raised by the pipeline. Private property rights, environmental impact, and possible economic implications are detailed by those who have been involved with the Nexus pipeline since its early stages of implementation.


Integration Of Hydrogeophysical Datasets For Improved Water Resource Management In Irrigated Systems, Catherine E. Finkenbiner May 2017

Integration Of Hydrogeophysical Datasets For Improved Water Resource Management In Irrigated Systems, Catherine E. Finkenbiner

School of Natural Resources: Dissertations, Theses, and Student Research

Water scarcity is predicted to be the major limitation to increasing agronomic outputs to meet future food and fiber demands. With the agricultural sector accounting for 80 – 90% of all consumptive water use and an average water use efficiency (WUE) of less than 45%, major advances must be made in irrigation water management. Precision agriculture, specifically variable-rate irrigation (VRI) and variable-speed irrigation (VSI) systems, offers the technologies to address and manage for infield variability and incorporate that into management decisions. The major limitation to implementing this technology often lies in the management of spatial datasets and the development of …


Heterogeneity Of Avian Breeding Habitat On Grazing Lands Of The Northern Great Plains, Maggi S. Sliwinski May 2017

Heterogeneity Of Avian Breeding Habitat On Grazing Lands Of The Northern Great Plains, Maggi S. Sliwinski

School of Natural Resources: Dissertations, Theses, and Student Research

Native rangelands in the Great Plains are largely privately owned and used for beef production. Vegetation heterogeneity is important for maintaining biodiversity, but private land may be more homogenous than desired. My research had two components: 1) to examine whether a variety of grazing strategies created vegetation heterogeneity in a large, intact rangeland, and 2) to understand beef producers’ attitudes about vegetation heterogeneity.

First, I sampled vegetation structure, composition, and bird abundance at multiple plots on eleven management units in Cherry County, Nebraska. Units were managed with commonly used grazing strategies (e.g., short-duration grazing and season-long continuous grazing). I examined …


Problematizing Socio-Scientific Issues: An Approach To Understanding Student Decision-Making Using Construal Level Theory, Ashley M. Peterson May 2017

Problematizing Socio-Scientific Issues: An Approach To Understanding Student Decision-Making Using Construal Level Theory, Ashley M. Peterson

School of Natural Resources: Dissertations, Theses, and Student Research

Socio-scientific issues (SSIs) are challenges at the intersection of science and everyday life that require use of scientific knowledge, argumentation skills, personal values, and morals to articulate science-informed decisions. While addressing SSIs, the ways in which individuals define a problem will influence the solution or decision reached. The problem definition can differ along many dimensions, including content and construal level. A construal is a mental construction of the past and future, other places and people, and unlikely events. Construal Level Theory (CLT) suggests pro-environmental intentions are associated with abstract situations. I explore the application of CLT to teaching and learning …


Living On The Edge: Assessing The Effects Of Catastrophic Fire On Plants Utilized By Two Endemic Subspecies Of Spring Mountains Butterflies, Charles Ryan Herrmann May 2017

Living On The Edge: Assessing The Effects Of Catastrophic Fire On Plants Utilized By Two Endemic Subspecies Of Spring Mountains Butterflies, Charles Ryan Herrmann

UNLV Theses, Dissertations, Professional Papers, and Capstones

In the past few decades there has been an increase in catastrophic, high-intensity, large-scale wildfires globally due to the combination of climate warming with more than a century of fire suppression policy. One region that has been drastically affected is the Western United States, as there has been an increase in ‘mega-fires’ in the past few decades. The 2013 Carpenter 1 Fire in the Spring Mountains, Nevada was the largest fire in recorded history in these mountains, spreading out over 11,137 hectares. Catastrophic fire like the Carpenter 1 Fire can have potentially devastating effects on endemic species inhabiting refugia on …


Spatiotemporal Analyses Of Recycled Water Production, Jana E. Archer May 2017

Spatiotemporal Analyses Of Recycled Water Production, Jana E. Archer

Electronic Theses and Dissertations

Increased demands on water supplies caused by population expansion, saltwater intrusion, and drought have led to water shortages which may be addressed by use of recycled water as recycled water products. Study I investigated recycled water production in Florida and California during 2009 to detect gaps in distribution and identify areas for expansion. Gaps were detected along the panhandle and Miami, Florida, as well as the northern and southwestern regions in California. Study II examined gaps in distribution, identified temporal change, and located areas for expansion for Florida in 2009 and 2015. Production increased in the northern and southern regions …


Management Of Predators, Prey, And Aviation Safety At Naval Air Station Patuxent River, Maryland: Can Coyotes Help Reduce Deer Strike Hazards?, Robert Lewis May 2017

Management Of Predators, Prey, And Aviation Safety At Naval Air Station Patuxent River, Maryland: Can Coyotes Help Reduce Deer Strike Hazards?, Robert Lewis

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

In the past 100 years, coyotes (Canis latrans) have expanded their range eastward. During their expansion, coyotes hybridized with gray wolves (Canis lupus) in the north and red wolves (Canis rufus) in the south. Coyotes were historically occupants of the plains, but now may be found in environments as varied as the sagebrush steppe, deserts, swamps, and inner cities. St. Mary’s County, MD, home to Naval Air Station Patuxent River (Pax River), was one of the last counties in the country to be colonized by coyotes. Pax River is a research and development/flight test and evaluation center, and houses numerous …


Riparian Buffered Sinkholes In The Blue River Watershed, Colin Copler Apr 2017

Riparian Buffered Sinkholes In The Blue River Watershed, Colin Copler

Undergraduate Theses

Riparian vegetation along streams has many positive effects on water quality and macroinvertebrate communities, especially in agricultural areas. Some of these effects include erosion prevention, pollutant removal, and lower summer water temperatures. There has been much research done examining the link between these riparian areas and streams; however, riparian vegetation is understudied in karst areas. Karst is a geologic formation that is composed of limestone, which dissolves in groundwater, forming sinkholes. Thus, the question this paper seeks to investigate is does riparian vegetation around sinkholes in a karst plain influence water quality within a watershed? Water quality, land cover, and …


Plant Diversity Influences The Structure And Function Of A Restored Prairie And Its Responses To Added Disturbances, Rebecca Bevans Apr 2017

Plant Diversity Influences The Structure And Function Of A Restored Prairie And Its Responses To Added Disturbances, Rebecca Bevans

School of Natural Resources: Dissertations, Theses, and Student Research

As global warming, human conversion of natural landscapes to agricultural uses, and widespread biodiversity losses continue to alter the ecosystems we depend on, an understanding of the relationship between ecosystem structure, composition, and function is needed to maintain valuable ecosystem states and their associated functions. Research testing the limits of an ecosystem’s ability to maintain essential structure and functioning under disturbance conditions can aid in this goal.

In this study, I measured the relationship between plant diversity, community structure and functional traits, and their responses to added disturbances. I added disturbances representing those either caused or intensified by human activity …


Mapping The Spatial-Temporal Variation In Ras Ghanada Seagrass Meadows And Sand Shoals Between 1996, 2006 & 2012, Ryan Brookbank Apr 2017

Mapping The Spatial-Temporal Variation In Ras Ghanada Seagrass Meadows And Sand Shoals Between 1996, 2006 & 2012, Ryan Brookbank

HCNSO Student Theses and Dissertations

Seagrass meadows offshore Ras Ghanada, as elsewhere, are an important component to the ecosystem providing numerous benefits to both aquatic and human life. This work focused on mapping the spatial and temporal distribution of seagrass meadows offshore Ras Ghanada using aerial photography acquired in 1996 and high-resolution satellite images captured in 2006 and 2012. The movements of sand shoals were also tracked, so as to further explain the dynamics of this ecosystem, as it is the area between the shoal crests that hosts the best developed seagrass meadows. The natural limiting factor for seagrass on the Ras Ghanada coastal shelf …


Evaluation Of Modis Land Surface Temperature Data To Estimate Near-Surface Air Temperature In Northeast China, Yuan Z. Yang, Wen H. Cai, Jian Yang Apr 2017

Evaluation Of Modis Land Surface Temperature Data To Estimate Near-Surface Air Temperature In Northeast China, Yuan Z. Yang, Wen H. Cai, Jian Yang

Forestry and Natural Resources Faculty Publications

Air temperature (Tair) near the ground surface is a fundamental descriptor of terrestrial environment conditions and one of the most widely used climatic variables in global change studies. The main objective of this study was to explore the possibility of retrieving high-resolution Tair from the Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) products, covering complex terrain in Northeast China. The All Subsets Regression (ASR) method was adopted to select the predictors and build optimal multiple linear regression models for estimating maximum (Tmax), minimum (Tmin), and mean (Tmean) air temperatures. …


Predation Risk: A Potential Mechanism For Effects Of A Wind Energy Facility On Greater Prairie-Chicken Survival, Jennifer A. Smith, Mary B. Brown, J.O. Harrison, Larkin A. Powell Apr 2017

Predation Risk: A Potential Mechanism For Effects Of A Wind Energy Facility On Greater Prairie-Chicken Survival, Jennifer A. Smith, Mary B. Brown, J.O. Harrison, Larkin A. Powell

School of Natural Resources: Faculty Publications

Recent expansion of the wind energy industry has raised concerns about the potential effects of wind energy facilities on prairie grouse. For example, efforts have been made to evaluate indirect effects on prairie grouse survival, but it is also critical to investigate the underlying mechanisms to direct conservation strategies. The objective of this study was to investigate the indirect effects of a wind energy facility on the survival of female Greater Prairie-Chickens (Tympanuchus cupido pinnatus) and on the occupancy of avian and mammalian predators. Between March and July of 2013 and 2014, we investigated spatial variation in predation risk by …


Ecosystem-Based Fisheries Management (Ebfm) Risk Assessment Of The Western Australian Abalone Managed Industry, F J. Webster, B Wise, Anthony M. Hart Apr 2017

Ecosystem-Based Fisheries Management (Ebfm) Risk Assessment Of The Western Australian Abalone Managed Industry, F J. Webster, B Wise, Anthony M. Hart

WA Marine Stewardship Council report series

This report provides a comprehensive overview of the Western Australian (WA) Abalone Managed Fishery (AMF) and the outcomes from the 2015 ecological risk assessment of this fishery. The AMF targets three species of abalone greenlip (Haliotis laevigata), brownlip (H. conicopora) and Roe’s abalone (H. roei). Greenlip and brownlip abalone are primarily targeted on the south coast of WA, while Roe’s abalone is primarily targeted on the West Coast. Commercial fishing for abalone in WA has been undertaken since 1964.


Nest Site Selection And Nest Survival Of Eastern Wild Turkeys In A Pyric Landscape, Nathan A. Yeldell, Bradley S. Cohen, Andrew R. Little, Bret A. Collier, Michael J. Chamberlain Apr 2017

Nest Site Selection And Nest Survival Of Eastern Wild Turkeys In A Pyric Landscape, Nathan A. Yeldell, Bradley S. Cohen, Andrew R. Little, Bret A. Collier, Michael J. Chamberlain

School of Natural Resources: Faculty Publications

Pine (Pinus spp.)-dominated forests are commonly managed with prescribed fire in the southeastern United States to reduce fuel loads, maintain diverse plant communities, and increase habitat quality for wildlife. Prescribed fire alters understory vegetation, which is a key component of nesting habitat for ground-nesting birds. We assessed the influences of vegetation, prescribed fire, and landscape features (e.g., roads, edge) on nest site selection and nest survival of eastern wild turkeys (Meleagris gallopavo silvestris) in a pine-dominated ecosystem in west-central Louisiana. We radio-marked 55 female wild turkeys and evaluated vegetation and landscape characteristics associated with 69 nests during the …


Hydraulics Near Unscreened Diversion Pipes In Open Channels: Large Flume Experiments, Ali Ercan, M. Levent Kavvas, Kara Carr, Zachary Hockett, Houssein Bandeh, Timothy D. Mussen, Dennis E. Cocherell, Jamilynn B. Poletto, Joseph J. Cech Jr., Nann A. Fangue Apr 2017

Hydraulics Near Unscreened Diversion Pipes In Open Channels: Large Flume Experiments, Ali Ercan, M. Levent Kavvas, Kara Carr, Zachary Hockett, Houssein Bandeh, Timothy D. Mussen, Dennis E. Cocherell, Jamilynn B. Poletto, Joseph J. Cech Jr., Nann A. Fangue

School of Natural Resources: Faculty Publications

Most of the water diversions on the Sacramento and San Joaquin Rivers (California, United States) and their tributaries are currently unscreened. These unscreened diversions are commonly used for irrigation and are potentially harmful to migrating and resident fishes. A large flume (test section: 18.29 m long, 3.05 m wide and 3.20 m high) was used to investigate the hydraulic fields near an unscreened water diversion under ecologically and hydraulically relevant diversion rates and channel flow characteristics. We investigated all combinations of three diversion rates (0.28, 0.42, and 0.57 m3/s) and three sweeping velocities (0.15, 0.38, and 0.61 m/s), …


Trap-Neuter-Return Programs And The Importance Of Associated Public Awareness, Nicolette Sliwa Apr 2017

Trap-Neuter-Return Programs And The Importance Of Associated Public Awareness, Nicolette Sliwa

Biology: Student Scholarship & Creative Works

The focus of this paper is to describe a typical Trap-Neuter-Return (TNR) program and highlight the major pros and cons surrounding this somewhat controversial method of managing the overwhelming free-roaming cat population. The effects of the species’ overabundance on the environment and human health are also discussed. Citing studies completed on TNR programs around the globe as well as mathematical models, the effectiveness of this method is compared to other, currently used alternatives. Finally, it has been suggested that the general awareness level a neighborhood possesses about the true goals of TNR programs has a potentially significant impact on the …


Droughtscape, Spring 2017, National Drought Mitigation Center Apr 2017

Droughtscape, Spring 2017, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Contents

Drought center helps islands reduce drought vulnerability

2017 sees above-average precipitation, warmer temps

California pulls out of drought

After tech transfer, training Tunisia launches first drought map

Drought center releases 2016 annual report

Book chapter focuses on drought and health

U2U wraps up, brings useful tools to farmers

Survey finds drought info leads to better decisions


Varying Perspectives On Landscape Diversity, Benet Kinghorn Apr 2017

Varying Perspectives On Landscape Diversity, Benet Kinghorn

Department of Environmental Studies: Undergraduate Student Theses

No abstract provided.


Population Structure Analysis Of Western Painted Turtles, Charrissa Zuerlein Apr 2017

Population Structure Analysis Of Western Painted Turtles, Charrissa Zuerlein

Department of Environmental Studies: Undergraduate Student Theses

Changes in the population structure, specifically the age, size and sex composition, of Western painted turtles can be studied to gain insight into the changes that will occur in closely related endangered species. As species with temperature-dependent sex determination (TSD), the sex ratios of new clutches are affected by climate, and this could cause problems for the species as climate changes occur. This study focuses on fluctuations in the population structure of a single population located near Cedar Point Biological Station in Ogallala, Nebraska. Each summer from 2005-2016 turtles were caught using floating basking traps and hoop nets. Results show …


Influences Of Catch-And-Release Angling On Fish Avoidance Behavior, Alexis D. Fedele Apr 2017

Influences Of Catch-And-Release Angling On Fish Avoidance Behavior, Alexis D. Fedele

School of Natural Resources: Dissertations, Theses, and Student Research

Newly opened recreational fisheries provide the opportunity to explore direct social impacts on controlled (i.e., managed), naïve (i.e., previously unexploited by anglers) population of fish. Herein, we examine the direct influence of angling on wild fish populations, and aim to identify the behavioral outcomes in fish resulting from angling through laboratory experiments. Using two naïve fish populations from newly opened reservoirs in Nebraska, we assessed the short-term (30 d) response of fish populations to recreational angling. At one reservoir, we noted declining catch rates in catch-and-release regulated fish but not in harvested-regulated fish. We hypothesized that catch-and-released fish were given …


Multi-Scaled Approaches For Protecting Montana's Watersheds And Water Resources, Elizabeth Yoder Apr 2017

Multi-Scaled Approaches For Protecting Montana's Watersheds And Water Resources, Elizabeth Yoder

Graduate Student Portfolios, Professional Papers, and Capstone Projects

The central theme carried among my four portfolio pieces is: using scientific and governmental approaches to conserve watershed health. For the purposes of this portfolio, I define watershed health as a very general term that describes the state of water quantity and quality that is available for human and ecosystem needs in a watershed. I see each of my portfolio pieces focusing on a different scale and method (i.e., science or government, including different levels of government, local, state and federal) for conserving watershed health. My first portfolio piece reviews water quality degradation caused by pharmaceuticals and personal care products …


Effects Of Timber Harvest On Avian Abundance And Diversity, Mckenzie Brandon Apr 2017

Effects Of Timber Harvest On Avian Abundance And Diversity, Mckenzie Brandon

Honors Capstones

No abstract provided.


Public Perception Of Leadership In The Municipal Solid Waste Sector, Allison Creeger Apr 2017

Public Perception Of Leadership In The Municipal Solid Waste Sector, Allison Creeger

Department of Environmental Studies: Undergraduate Student Theses

No abstract provided.


Saving Money While Participating In Urban Agriculture, Jill Wieneke Apr 2017

Saving Money While Participating In Urban Agriculture, Jill Wieneke

Department of Environmental Studies: Undergraduate Student Theses

With more and more people pouring into urban areas, many have become unattached to where their food comes from and are disengaged with local food systems. Urban agriculture (UA) can bring people closer to healthy foods and be a potential savings. This will bring more resilience to a community and amend food insecurities Through this case study at the Hawley Hamlet Neighborhood Garden, urban gardeners can understand the capabilities of UA and the effects of food affordability into urban settings. This case study is an example of vegetable outputs and cost savings that can be obtained at a community garden …


Distribution And Condition Of Stony Corals In The Veracruz Reef System National Park: A Management Perspective, Mauricio López Padierna Mar 2017

Distribution And Condition Of Stony Corals In The Veracruz Reef System National Park: A Management Perspective, Mauricio López Padierna

HCNSO Student Theses and Dissertations

The Veracruz Reef System (VRS) is located in the southwestern Gulf of Mexico. It is comprised of 28 coral reefs in various stages of development and conservation. They are protected under the Parque Nacional Sistema Arrecifal Veracruzano National Park created in 1992. There are many threats to the reefs of the VRS, including the Port and city of Veracruz, which hosts half a million inhabitants and Mexico’s oldest active port. The inhabitants of Veracruz have used reef resources for thousands of years, as evidenced in archaeological sites on Sacrificios island, and constructions throughout the city, most notably in the San …


Influence Of Internal Variability On Population Exposure To Hydroclimatic Changes, Justin S. Mankin, Daniel Viviroli, Mesfin Mekonnen, Arjen Y. Hoekstra, Radley M. Horton, Jason E. Smerdon, Noah S. Diffenbaugh Mar 2017

Influence Of Internal Variability On Population Exposure To Hydroclimatic Changes, Justin S. Mankin, Daniel Viviroli, Mesfin Mekonnen, Arjen Y. Hoekstra, Radley M. Horton, Jason E. Smerdon, Noah S. Diffenbaugh

Daugherty Water for Food Global Institute: Faculty Publications

Future freshwater supply, human water demand, and people’s exposure to water stress are subject to multiple sources of uncertainty, including unknown future pathways of fossil fuel and water consumption, and ‘irreducible’ uncertainty arising from internal climate system variability. Such internal variability can conceal forced hydroclimatic changes on multi-decadal timescales and near-continental spatial-scales. Using three projections of population growth, a large ensemble from a single Earth system model, and assuming stationary per capita water consumption, we quantify the likelihoods of future population exposure to increased hydroclimatic deficits, which we define as the average duration and magnitude by which evapotranspiration exceeds precipitation …