Physical Sciences and Mathematics Commons^™

Increase In Ponderosa Pine Density In The Nebraska Sandhills: Impacts On Grassland Plant Diversity And Productivity, Alexa Armstrong

Department of Environmental Studies: Undergraduate Student Theses

Increase in woody species encroachment into semi-arid grasslands and savannas has been of great concern at a global level. Temperature and precipitation are key factors determining vegetation cover; however other factors, such as fire regime and grazing may be at play in semi-arid ecosystems. Historically, in Nebraska’s semi-arid grasslands, woody species have been controlled by periodic fires. Changes in social values and land use, fire suppression, overgrazing, increased N deposition, and climate change, have attributed to the observed shift from grasslands to shrublands or woodlands. The primary objectives of this study were to determine the impacts of Ponderosa pine ( …

A Comparison Of The Effectiveness Of Scent Lures On Attracting Mesopredators, Tom Batter

Department of Environmental Studies: Undergraduate Student Theses

A mesopredator is a medium-sized middle trophic level predator such as a raccoon (Procyon lotor), red fox (Vulpes vulpes), striped skunk (Mephitis mephitis), or coyote (Canis latrans; Crooks and Soule 1999). Mesopredators have long been trapped for recreational, economic, or academic reasons. Throughout human history trapping has been used to capture animals for food and skins, as well as to prevent personal harm and property damage from predators. In order to increase the probability of success, scent lures are often used as an attractant (Geary 1984, Mills et al. 2010, Schlexer 2008).

Prey Selection By The Northern Watersnake, Nerodia Sipedon, Kyle O' Connell

Department of Environmental Studies: Undergraduate Student Theses

Prey selection and composition of the northern waternake, Nerodia sipedon was investigated between 8/2010 and 3/2011 by palpation of stomach contents in the field and conducting laboratory trials. 41 snakes were captured, five yielded prey contents. Fish parts, freshwater mussels, and an insect exoskeleton were found. No amphibians were found despite availability at study sites. Snakes in the laboratory underwent 22 trials, feeding on 11 occasions. Snakes fed on an equal number of both fish species, revealing no selection. Further research is needed to determine the rate of digestion of N. sipedon.

Herpetofaunal Diversity At Yankee Hill State Lake And Wildlife Management Area, Lancaster County, Nebraska, Shelby Klima

Department of Environmental Studies: Undergraduate Student Theses

A survey for amphibians and reptiles was conducted in March through October 2011 at Yankee Hill Wildlife Management Area in Lancaster County, Nebraska. The survey was conducted using several different techniques including: visual and auditory encounters, artificial and natural cover objects, aquatic trappings and road surveys. A total of 145 individuals representing 12 species were identified including seven reptiles and five amphibians. A total of 48% of the species that may potentially occur on the site were encountered, all of which are common, widely distributed generalist species. Neither Graham’s Crayfish Snake nor the Massasauga, both target species for this survey, …

Avian Species Abundance In Response To Recreational Trail Use, Carrie A. Wencel

Department of Environmental Studies: Undergraduate Student Theses

Studies have indicated that non-consumptive outdoor recreation may affect wildlife. Thus, as the nation increases interest in outdoor recreation, data suggests the effect on wildlife will also increase. Previous studies indicate that as disturbance to wildlife increases, both avian species richness will decrease. Knowing how to anticipate effects on native species when planning and managing recreational areas is important in order to both provide for human desires and ensure the least impact to local species diversity.

The goal of this project was to observe and compare avian species richness and diversity between selected trail sites within Shevlin Park, Bend, Oregon …

The Distribution And Life Cycle Of Alliaria Petiolata In Lincoln, Nebraska, Caleb Pharris

Department of Environmental Studies: Undergraduate Student Theses

Alliaria petiolata (Garlic Mustard) is a biennial alien invasive plant species of the Brassicacea family. It is responsible for displacing native plant species throughout North America and its management has proven to be extremely difficult. Recently several populations of Alliaria petiolata have been discovered in southwestern Lincoln, Nebraska. The spread of Alliaria petiolata is a concern for natural resource managers and the general public. Due to the difficulty of its control, Alliaria petiolata is capable of creating monocultures which diminish the aesthetic value of an ecosystem. While most commonly found in the understory of hardwood forests, it is capable of …

Ecotourism In Costa Rica: Environmental Impacts And Management, Emily Mckeone

Department of Environmental Studies: Undergraduate Student Theses

Globally we are witnessing growing environmental destruction, particularly to the natural resource bases of underdeveloped countries. If ecotourism can generate profits for local economies, while protecting and conserving the natural resource base of that community, it could be a strong alternative for numerous countries. Evidence suggests that the ecotourism industry has been expanding at a rapid rate in recent decades (Dasenbrock 2002). It is important to understand the positive and negative ecological impacts of the industry as this rapid growth rate continues.

The main objective of this study is to highlight the strengths and weaknesses of the ecotourism industry in …

An Assessment Of Stable Hydrogen-Isotope Analysis Methods To Assign Geographic Origin To Migratory Red-Tailed Hawks (Buteo Jamaicensis), Carla Marie Ahlschwede

Department of Environmental Studies: Undergraduate Student Theses

Stable-hydrogen isotopes are becoming an increasingly popular method of studying migratory birds, though sample preparation methods may affect results. In this study I examined feathers from red-tailed hawks (Buteo jamaicensis) to determine the relationship between measure of δD due to inter-feather variation or drying methods, assessed the accuracy of results by using two birds of known-origin and estimated possible natal origins of migratory red-tailed hawks. Two feathers per individual were taken from 81 wild hawks caught at Hitchcock Nature Center near Crescent IA and from 2 rescued red-tailed hawks, Raptor Recovery Nebraska near Eagle, NE. 119 of the …

Communication For Mate Selection In Anurans: Dominant Frequency Versus Snout-Vent-Length, Shari Jean Kunert

Department of Environmental Studies: Undergraduate Student Theses

No abstract provided.

How Are The Torres Strait Islander's Traditional Hunting Practices Affected By The Current Rate Of Decline In Dugong And Sea Turtle Populations And The Australian Government's Co-Management Policies On Marine Preservation?, Katilyn Price

Department of Environmental Studies: Undergraduate Student Theses

This paper will attempt to identify the extent to which the Torres Strait Islanders traditional hunting practices have been disrupted by the overall decline in dugong and sea turtle populations, which has directly correlated to an increase in hunting restrictions put in place by the Australian Government. The traditional hunting of dugongs and sea turtles provides not only a food source, but brings prestige to the men who catch them and serves as an educational platform to teach the younger generations about their culture. There are many environmental threats that impact the populations of sea turtles and dugongs though the …

Is Orthoptera Abundance And Distribution Across A Small Grassland Area Affected By Plant Biomass, Plant Species Richness, And Plant Quality?, Caitlin Falcone

Department of Environmental Studies: Undergraduate Student Theses

The choice of a specific microhabitat represents a compromise among a number of different factors organisms use to monitor habitat suitability. Grassland vegetation structure can vary widely along environmental gradients over a relatively small area. This vegetation structure can have a large influence on habitat selection by grasshoppers (Orthoptera). However, it is not clear which vegetation characteristics are most important in determining grasshopper abundance. We found that plant biomass, plant species richness, and plant quality all have an effect on grasshopper abundance and distribution. We observe that these affects vary both within and among the two years of data collection. …

River Sediment Sampling Methods- Causeway Building And Removal, Dillon Dittmer

Department of Environmental Studies: Undergraduate Student Theses

Abstract The Environmental Protection Agency (EPA) and U.S. Fish and Wildlife Service (USFWS) suspect that causeways have a negative impact on river ecology both when installed and when removed. The Nebraska Department of Roads routinely uses causeways as a tool in the construction and repair of bridges. Although research has not been conducted on the impact of causeway building and removal data has been collected about the impact of dams, causeways, etc. on estuaries. This data is considered subjective and authors often cite sampling methods as a source of error. Currently there are no widely used handheld sampling methods that …

Herbicides And Amphibian Populations, Zach Shirk

Department of Environmental Studies: Undergraduate Student Theses

Amphibians are a unique class of species that are found worldwide except Antarctica and Greenland. They range in size from a few millimeters to over six feet long. Amphibian’s habitats are as various as their size, but one thing in common is that amphibians require an aquatic location to breed. Amphibians live in deserts, mountain prairies, rain forest, wetlands, and almost everywhere in between. Amphibians are an integrated part of most natural ecosystems across the world. Amphibians are a critical part of many food chains; they provide the important link between secondary and tertiary consumers. Amphibians are indicator species in …

Relatin Dissolved Oxygen Concentration To Fish Distribution In Jarecki Lake, Adam Sutton

Department of Environmental Studies: Undergraduate Student Theses

Abstract Water temperature and dissolved oxygen (DO) profiles were measured once every month from mid July to mid February in a relatively deep sand-pit lake in southeast Nebraska. These profiles showed depleted DO concentrations below the thermocline during summer stratification indicating areas fish will likely avoid in summer months. Colder temperatures in fall caused complete mixing of the water column allowing fish to inhabit all depths of the lake. An inverse temperature stratification occurred directly below the ice during winter months as ice cover cooled the surface water to below 4 degrees Celsius. Ice cover also blocked air – water …

A Proposed Plan For Managing Eastern Nebraska's Saline Wetlands, Vandhana Rabadinanth

Department of Environmental Studies: Undergraduate Student Theses

Abstract Eastern Nebraska’s saline wetlands play a major role in Nebraska’s environmental place in the world. Besides the role of scientific changes being important, education also is essential in the conservation of these wetlands. Through the observation of Salt Creek tiger beetle (Cicindela nevadica lincolniana) and soil electroconductivity, I propose that we need to reform Nebraska’s education system to help schools play a bigger part in environmental issues such as this one. There is a drastic trend in the correlations between Salt Creek tiger beetle populations and wetland degradation. Since many Lincoln residents have a limited knowledge of what is …

Relating Fires Affect On Forest Succession And Forest's Effect On Fire Severity In One Burned And Unburned Environment, Tyler Jay Seiboldt

Department of Environmental Studies: Undergraduate Student Theses

Wildfires are a natural part of many forest ecosystems and play a vital role in maintaining their health. Wildfires can have a critical influence on a landscapes plant community through their relative frequency, seasonality, and severity. One of the most heavily influenced regions by wildfire disturbance is the Klamath Mountain region of California. I looked at the affect a wildfires severity had on the Whiskey creek valley within the Whiskeytown National Recreation Area. 8 tree species and 4 flower species were examined on both the burned and unburned regions within this valley nearly a year after the wildfire (May 17-23 …

Using Gis To Locate Areas For Growing Quality Coffee In Honduras, Ellen Mickle

Department of Environmental Studies: Undergraduate Student Theses

Abstract Small-scale coffee producers worldwide remain vulnerable to price fluctuations after the 1999-2003 coffee crisis. One way to increase small-scale farmer economic resilience is to produce a more expensive product, such as quality coffee. There is growing demand in coffee-producing and coffee-importing countries for user-friendly tools that facilitate the marketing of quality coffee. The purpose of this study is to develop a prototypical quality coffee marketing tool in the form of a GIS model that identifies regions for producing quality coffee in a country not usually associated with quality coffee, Honduras. Maps of areas for growing quality coffee were produced …

Impacts Of Plant Size, Density, Herbivory, And Desease On Native Platte Thistle (Cirsium Canescens), Deidra Jacobsen

Department of Environmental Studies: Undergraduate Student Theses

Abstract. Based on prior field observations, we hypothesized that individual and interacting effects of plant size, density, insect herbivory, and especially fungal disease, influenced seedling and juvenile plant growth in native Platte thistle populations (Cirsium canescens Nutt.). We worked at Arapaho Prairie in the Nebraska Sandhills (May - August 2007), monitoring plant growth, insect damage, and fungal infection within different density thistle patches. In the main experiment, we sprayed half of test plants in different density patches with fungicide (Fungonil© Bonide, containing chlorothalonil) and half with a water control. Fungal infection rates were very low, so we found no difference …

A Survery Of Western United States Instream Flow Programs And The Policies That Protect A River's Ecosystem, Kyle Jackson

Department of Environmental Studies: Undergraduate Student Theses

The Western United States can best be described as a vast, varying land, with the high plains to the east and the jagged horizons of Rockies to the west. However there is one common trait shared by these states: the lack of water resources. With the continued development of this land, the fact that water is scarce is becoming more real. This issue became more difficult to handle as the public became more aware that many competing uses existed for the finite resource, and those different uses were degrading the natural environments of the surface waters. With this realization instream …

Variations In Stomatal Traits Of 14 Bornean Tree Species Growing On Soils With Different Moisture Contents In Lambir Hills National Park, Whitney Logan Cannon

Department of Environmental Studies: Undergraduate Student Theses

The goal of this study was to look at variations in stomatal traits of tree species on soils with different moisture contents and fertility at Lambir Hills National Park. Stomates are important structures on the surface of leaves that mediate conduction of moisture and gassesin and out of the leaf. If stomatalt raits are important for regulation, then there should be variation in stomatal traits in regards to their soil specialization. The 14 Borneant ree speciess ampledi ncluded6 sandyl oam specialists6, clay specialistsa nd 2 generalistsfo und growing with equald istributionso n both sandyl oam and clay. Confocal microscopy was …