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Full-Text Articles in Physical Sciences and Mathematics

A System Dynamics Model Of Soil Carbon Stock And Flows In Grasslands Under Climate And Grazing Scenarios., Deirdre Sommerlad-Rogers Jun 2021

A System Dynamics Model Of Soil Carbon Stock And Flows In Grasslands Under Climate And Grazing Scenarios., Deirdre Sommerlad-Rogers

Master's Theses

Carbon sequestration is paramount to reducing climate change. Grasslands, representing 40% of all terrestrial area, can serve as a primary sequestration location if optimal management strategies can be realized. This study used system dynamics modeling to examine the temporal dynamics of carbon stocks and flows in response to grass species composition, grazing intensity, and temperature and precipitation changes at the landscape level. While there are other biogeochemical models in existence, they are either meant to model large areas, including globally, or are meant to be at a farm level and have limited plot sizes, limiting the options for rangeland managers …


An Investigation Into Historical And Contemporary Breeding Occurrence Of The Ferruginous Hawk In Kansas, Erica Clark Jan 2021

An Investigation Into Historical And Contemporary Breeding Occurrence Of The Ferruginous Hawk In Kansas, Erica Clark

Master's Theses

The Ferruginous Hawk (Buteo regalis) is the largest Buteo species occurring in grasslands, nesting along bluffs, buttes and isolated trees. In Kansas, the Ferruginous Hawk is listed as a Species of Greatest Conservation Need, Tier II. A previous study on Ferruginous Hawks nesting in Kansas during the years of 1979 to 1987, with sporadic visits from the 1990s to 2000, revealed that the most productive nesting territories were inaccessible to predators, placed on rocky ledges and the surrounding landscape was over 50% rangeland. I revisited 82 of the 111 historic nest territories in the summers of 2019 and …


Phantom Ocean, Real Impact: Natural Surf Sound Experiments Alter Foraging Activity And Habitat Use Across Taxa, Ryan N. Wardle Dec 2020

Phantom Ocean, Real Impact: Natural Surf Sound Experiments Alter Foraging Activity And Habitat Use Across Taxa, Ryan N. Wardle

Master's Theses

A growing body of research focuses on how background sounds shape and alter critical elements of animals’ lives, such as foraging behavior, habitat use, and ecological interactions (Bradbury & Vehrencamp, 2011; Barber et al., 2010; Kight & Swaddle, 2011; Shannon et al., 2016). Much of this research has centered on the effects of anthropogenic noise (Dominoni et al., 2020; Francis & Barber, 2013; Ortega, 2012; Swaddle et al., 2015), but recent studies have also revealed that natural sound sources can influence animal behavior (Davidson et al., 2017; Le et al., 2019). Natural sounds, such as crashing surf, can create conditions …


Host Plant Resistance In Strawberries To Anthracnose And Colonization Of Crown And Root Tissue By Verticillium Dahliae And Macrophomina Phaseolina, Omar A. Gonzalez-Benitez Jun 2020

Host Plant Resistance In Strawberries To Anthracnose And Colonization Of Crown And Root Tissue By Verticillium Dahliae And Macrophomina Phaseolina, Omar A. Gonzalez-Benitez

Master's Theses

Strawberries are considered an important crop in California where in 2018 it was in the top 5 valued fruit and vegetable commodities valued at $2.84 billion accounting for 88% of the total U.S. production. Strawberry production can be severely impacted by soilborne pathogens that can affect strawberry roots, crowns and leaves which can result in plant mortality. As much as 50 to 60% mortality can occur in one field. Pathogens responsible for such losses include Colletotrichum acutatum (syn.C. nymphaeae), Macrophomina phaseolina and Verticillium dahliae. With the phaseout of methyl bromide, host resistance and an understanding of host-pathogen interactions …


Influence Of Natural And Anthropogenic Environmental Variability On Larval Fish Diet, Growth, And Condition In The Northcentral Gulf Of Mexico, Angie Hoover Dec 2018

Influence Of Natural And Anthropogenic Environmental Variability On Larval Fish Diet, Growth, And Condition In The Northcentral Gulf Of Mexico, Angie Hoover

Master's Theses

The northern Gulf of Mexico experiences high levels of freshwater runoff annually from various sources including the Mississippi River and Mobile Bay, among other sources. Early life history stages of fishes are especially vulnerable to environmental variability created by freshwater discharge. The objectives of this study were to describe the available prey field, diet, growth and condition of larval fishes with respect to various effects of freshwater discharge in the northern Gulf. The first chapter compared these parameters in larval Gulf Menhaden (Brevoortia patronus) collected from three different water masses characterized by physical and biological parameters after the …


Philosophers On The Fringe: Albert Schweitzer, Liberty Hyde Bailey, Aldo Leopold, And The Wrongful Polarization Of Environmentalist History 2017, Minnie A.M. Lauzon May 2017

Philosophers On The Fringe: Albert Schweitzer, Liberty Hyde Bailey, Aldo Leopold, And The Wrongful Polarization Of Environmentalist History 2017, Minnie A.M. Lauzon

Master's Theses

This thesis includes three articles (chapters) intending to encourage clarification of an area of environmental history that has not received adequate attention since the publication of Roderick Nash’s Wilderness and the American Mind. Since its publication in 1967, little research has been dedicated to understanding the scholarly or philosophical influence Albert Schweitzer and Liberty Hyde Bailey had on Aldo Leopold. Since my undertaking of this topic, I have established two primary goals. First, I want to provide clarification to environmentalists, academics, and the populace at large that environmentalism does not have to be bound by rules and convention, but can …


Naturalists’ Perspectives On The Use Of Mobile Technology During A Nature Hike, Aubin Marishka Radzewicz St. Clair Aug 2015

Naturalists’ Perspectives On The Use Of Mobile Technology During A Nature Hike, Aubin Marishka Radzewicz St. Clair

Master's Theses

Naturalists act as our link between scientific knowledge and the public’s understanding of natural history and conservation efforts. In order for them to succeed, they need access to reference materials as well as up-to-date information (Mankin, Warner, & Anderson, 1999). Incorporating mobile technology (i.e. tablets) into naturalists’ endeavors in natural history and environmental education can be used as supportive and educational tools. My project investigated how newly trained naturalists used tablet technology while leading groups of children on nature hikes. I investigated naturalists’ views on the use of mobile technology as a tool during the hikes. My research was guided …


An Analysis Of Juvenile Chinook Salmon Outmigration Speed And Survival In Response To Habitat Features: Sacramento River From Knights Landing To Sacramento, California, Natalie N. Mcnair Jun 2015

An Analysis Of Juvenile Chinook Salmon Outmigration Speed And Survival In Response To Habitat Features: Sacramento River From Knights Landing To Sacramento, California, Natalie N. Mcnair

Master's Theses

Outmigration is an important life stage for Chinook salmon (Oncorhynchus tshawytscha) survival in the Sacramento River, and yet our understanding of their behavior and needs during this time is limited. To gain a better understanding of their survival and movement rates during outmigration, late fall run Chinook salmon smolts were tracked using acoustic telemetry techniques. Habitat features were measured and quantified throughout the study area to evaluate how Chinook salmon respond to key levee features including shade, instream woody material, and aquatic vegetation. The overall average movement speed through the entire study area was 0.77 m/s with an …


Comparison Of Two Potential Streamgage Locations On Scott Creek At Swanton Pacific Ranch, California, Matthew C. Scrudato Jun 2010

Comparison Of Two Potential Streamgage Locations On Scott Creek At Swanton Pacific Ranch, California, Matthew C. Scrudato

Master's Theses

Two locations on Scott Creek, located 12 miles north of Santa Cruz California, are being considered for the installation of a streamgage to measure discharge. Each location offers unique considerations and challenges in gage construction and discharge measurement capabilities. A detailed flood frequency analysis was completed using a direct watershed comparison, direct equations developed by Waananen and Crippen, a Log Pearson Type III Frequency Distribution, a regional analysis, and two-station comparisons. Final results indicate a 100-year recurrence interval of 6,310 ft3/s at the Upper Scott Creek location and 6,520 ft3/s at the lower location. A detailed indirect measurement revealed that …


Influences Of Environmental Education Programs On The Participant's Affinity For Nature, Justin Alan Schmillen Jun 2010

Influences Of Environmental Education Programs On The Participant's Affinity For Nature, Justin Alan Schmillen

Master's Theses

This study was conducted to determine the change, and the factors influencing the change, in the participant’s affinity for nature resulting from an environmental education experience. In addition, this study also examined the change and factors of change in aspects of the participant’s affinity for nature that directly relate to marine and coastal resources and environments. An adapted version of the Affinity for Nature scale, an outcome measuring instrument used by the American Camp Association was used to collect data from participants (n=529) at Rancho El Chorro Outdoor School and Camp Ocean Pines, whose experience included an overnight component and …


Influence Of Clay Mineralogy On Soil Dispersion Behavior And Water Quality, Jessique L. Ghezzi May 2010

Influence Of Clay Mineralogy On Soil Dispersion Behavior And Water Quality, Jessique L. Ghezzi

Master's Theses

Currently, there is very little research available on nonpoint source pollution from rural watersheds. Government regulatory agencies are desperate for information regarding the causes of nonpoint source pollution, which includes the relationship between suspended soil particles and dispersion. Since soil dispersion is dependent on clay mineralogy, knowing the clay mineralogy of the soil in an area can help predict sediment loads entering the surrounding surface waters. This information is necessary to protect the resource value of our rivers, lakes, and estuaries, as well as to protect recreational activities such as fishing or hunting; but most importantly, this information is necessary …


Tall Fescue (Lolium Arundinaceum (Schreb.) S.J. Darbyshire) Cultivar Performance In The Central California Coastal Region, Seril Shimizu Jan 2009

Tall Fescue (Lolium Arundinaceum (Schreb.) S.J. Darbyshire) Cultivar Performance In The Central California Coastal Region, Seril Shimizu

Master's Theses

Tall fescue (Lolium arundinaceum (Schreb.) S.J. Darbyshire) has long been known as a turfgrass that utilizes lower levels of inputs than most other cool season turfgrasses (Turgeon, 2005). In recent years, turf breeders have been selecting for cultivars of tall fescue that have finer leaf textures. As the use of tall fescue expands, consumers want to now what cultivar to use and how to manage it. This study looked at 18 tall fescue cultivars grown at two mowing heights of five and 10 centimeters and evaluated plant quality based on stand density, leaf texture, and genetic plant color. In the …