Digital Commons Network^™

Discontinuity Analysis Reveals Alternative Community Regimes During Phytoplankton Succession, David G. Angeler, Craig R. Allen, Dirac L. Twidwell Jr., Monika Winder

School of Natural Resources: Faculty Publications

It is well-recognized in plankton ecology that phytoplankton development can lead to distinct peaks (i.e., blooms) during spring and summer. We used a 5-year (2007–2011) phytoplankton data set and utilized discontinuity analysis to assess resilience attributes of spring and summer blooms based on the cross-scale resilience model. Using the size structure (i.e., cross-scale structure as an indicator of resilience) in the sampled plankton data, we assessed whether spring and summer blooms differ substantially between but not within blooms; that is, whether they comprise alternative community regimes. Our exploratory study supported this expectation and more broadly resilience theory, which posits that …

Proposal To Build A Green Roof On Top Of Hardin Hall On Unl's East Campus, Abbie Andersen

Department of Environmental Studies: Undergraduate Student Theses

The purpose of this study is to research the feasibility of implementing more green roofs around The University of Nebraska-Lincoln’s campuses. To do this investigation a systematic literature review process was used gathering multiple relevant, peer reviewed articles from UNL’s “Encore” search engine. The data was then organized into categories that described the necessary considerations that needed to be made to retrofit green roofs, information on their many benefits, and finally the potential energy cost savings that can be obtained through use of a green roof. From here a proposal for a model green roof on top of UNL’s Hardin …

Amphibian And Reptile Community Responses To Forest And Riparian Disturbance, Jacquelyn Christine Guzy

Graduate Theses and Dissertations

Riparian zones are transitional, semi-terrestrial areas regularly influenced by freshwater. These areas serve as dispersal corridors for many animal and plant species and ultimately function as important reservoirs of biodiversity in altered landscapes. While much of the riparian habitat in the United States has been affected by anthropogenic activities, management actions may mitigate potentially negative influences of these activities. For example, Streamside Management Zones (i.e., riparian buffers; SMZs) are commonly implemented within managed forests to protect water quality, but may also provide habitat for riparian-associated wildlife. Yet, little research has rigorously addressed the value of SMZs for wildlife, particularly cryptic …

Is Grassfed Meat And Dairy Better For Human And Environmental Health?, Frederick D. Provenza, Scott L. Kronberg, Pablo Gregorini

Wildland Resources Faculty Publications

The health of livestock, humans, and environments is tied to plant diversity—and associated phytochemical richness—across landscapes. Health is enhanced when livestock forage on phytochemically rich landscapes, is reduced when livestock forage on simple mixture or monoculture pastures or consume high-grain rations in feedlots, and is greatly reduced for people who eat highly processed diets. Circumstantial evidence supports the hypothesis that phytochemical richness of herbivore diets enhances biochemical richness of meat and dairy, which is linked with human and environmental health. Among many roles they play in health, phytochemicals in herbivore diets protect meat and dairy from protein oxidation and lipid …

Wildfire Alters Spatial Patterns Of Available Soil Nitrogen And Understory Environments In A Valley Boreal Larch Forest, Jianjian Kong, Jian Yang, Bo Liu, Lin Qi

Forestry and Natural Resources Faculty Publications

Wildfire, a primary natural disturbance in many forests, affects soil nutrient availability and spatial distributions of forest plants. However, post-fire changes in soil nutrients and spatial patterns of understory environments at fine scales are poorly understood. Here, we characterized spatial patterns of soil nitrogen availability and site characteristics at a 3-year-post-fire and an unburned site in a valley boreal larch forest. We also examined the relationship between soil nitrogen availability and site characteristics. The results showed that the burned site had higher NO₃⁻ and lower NH₄⁺ than the control. The herb, litter and coarse wood debris …

A Prairie And Its People: Conflict And Cooperation. E. Frank Schramm, Joseph E.A. Alexis, The Amos Eager Family, The University Of Nebraska And Other Notable Owners Of Nine Mile Prairie And Its Environs, Jon H. Oberg

University of Nebraska State Museum: Staff and Affiliates, Publications

This study looks at the social history of individuals connected to a particular geographic quadrant -- Section 1 of Middle Creek precinct, Lancaster County, Nebraska. This an area famous for its natural history, as it is the home of Nine Mile Prairie. But the property owners in this section have a colorful history that encompasses the fields of sports, politics, academics, foreign wars, and crime. The study looks primarily at E. Frank Schramm, Joseph E.A. Alexis, and the Amos Eager family, who with other owners contributed importantly to the history and development of the City of Lincoln and the State …

Implications Of Channel Catfish Movement In An Internationally Managed System, Henry Hansen

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

The large-scale movements and spatial behavior of channel catfish in the Red River of the North, have direct interactions with geopolitics, anthropogenic structures, and ecosystems. Investigating the spatial dynamics and exploitation of this mobile and internationally managed fish species provides opportunities for resource managers to design evidence­-based policy for the diverse interest groups that utilize the fishery. My thesis comprised two parts: 1) characterize system­wide movement and survival patterns using mark­-recapture methods and acoustic telemetry and 2) project the interaction of hypothetical exploitation scenarios and alternative movement methodologies to assess the fishery from an ecosystem service flow perspective. Channel catfish …

Estimating The Use Of Public Lands: Integrated Modeling Of Open Populations With Convolution Likelihood Ecological Abundance Regression, Lutz F. Gruber, Erica F. Stuber, Joseph J. Fontaine

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

We present an integrated open population model where the population dynamics are defined by a differential equation, and the related statistical model utilizes a Poisson binomial convolution likelihood. Key advantages of the proposed approach over existing open population models include the flexibility to predict related, but unobserved quantities such as total immigration or emigration over a specified time period, and more computationally efficient posterior simulation by elimination of the need to explicitly simulate latent immigration and emigration. The viability of the proposed method is shown in an in-depth analysis of outdoor recreation participation on public lands, where the surveyed populations …

Identifying Priority Conservation Areas And Strategies For Myotis Sodalis (Chiroptera: Vespertilionidae) Via Habitat And Connectivity Modeling, Ashleigh B. Cable

Masters Theses

Myotis sodalis, the Indiana bat, is a federally endangered bat species in the United States of America (USA). Conservation efforts are typically focused at identified maternity sites at local scales, however, the species is a regional migrant that interacts with its environment at multiple spatial scales. We are limited in our knowledge of landscape-level requirements of this species, especially in large areas such as Illinois, USA, where a wide range of environmental and landscape conditions exist. Many previous M. sodalis habitat studies have limited their focus to smaller spatial scales. Due to limitations in funding, personnel, and time, it …

Early Warnings For State Transitions, Caleb P. Roberts, Dirac Twidwell, Jessica L. Burnett, Victoria M. Donovan, Carissa L. Wonkka, Christine L. Bielski, Ahjond S. Garmestani, David G. Angeler, Tarsha Eason, Brady W. Allred, Matthew O. Jones, David E. Naugle, Shana M. Sundstrom, Craig R. Allen

School of Natural Resources: Faculty Publications

New concepts have emerged in theoretical ecology with the intent to quantify complexities in ecological change that are unaccounted for in state-and-transition models and to provide applied ecologists with statistical early warning metrics able to predict and prevent state transitions. With its rich history of furthering ecological theory and its robust and broad-scale monitoring frameworks, the rangeland discipline is poised to empirically assess these newly proposed ideas while also serving as early adopters of novel statistical metrics that provide advanced warning of a pending shift to an alternative ecological regime. We review multivariate early warning and regime shift detection metrics, …

Why Do They Do That? Understanding Factors Influencing Visitor Spatial Behavior In Parks And Protected Areas, Abigail M. Sisneros-Kidd

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Visitors to parks and protected areas within the United States and worldwide often visit these areas with a particular destination in mind, such as seeing Old Faithful erupt in Yellowstone National Park or standing on the rim of the Grand Canyon in Grand Canyon National Park. These visitor use destinations, and the pathways leading to them, such as trails and roadways, see high levels of use, and as a result, impacts to soil, vegetation, air, water, soundscapes, and night skies that result from this use. The field of recreation ecology studies these impacts to park and protected area resources resulting …

Book Reviews: Force Of Nature: George Fell, Founder Of The Natural Areas Movement. Arthur Melville Pearson., James R. Herkert

The Prairie Naturalist

Arthur Melville Pearson’s Force of Nature is a book that tells two very interesting and intertwined stories. One is a story of how perseverance and determination can drive an individual to accomplish great things. And the other is a story of how the modern day natural areas movement came to be. Fortunately for those interested in conservation and natural areas protection, those two stories were combined in the life of George Fell (1916-1994). In Fell’s home state of Illinois, where his impact is widely known, his name is synonymous with conservation. In other places where his impact is less well …

Present And Future Thermal Environments Available To Sharp-Tailed Grouse In An Intact Grassland, Edward J. Raynor, Larkin Powell, Walter H. Schacht

School of Natural Resources: Faculty Publications

Better understanding animal ecology in terms of thermal habitat use has become a focus of ecological studies, in large part due to the predicted temperature increases associated with global climate change. To further our knowledge on how ground-nesting endotherms respond to thermal landscapes, we examined the thermal ecology of Sharp-tailed Grouse (Tympanuchus phasianellus) during the nesting period. We measured site-specific iButton temperatures (TiB) and vegetation characteristics at nest sites, nearby random sites, and landscape sites to assess thermal patterns at scales relevant to nesting birds. We asked if microhabitat vegetation characteristics at nest sites matched the characteristics that directed macrohabitat …

Effects Of Patch Size And Basal Area On Avian Taxonomic And Functional Diversity In Pine Forests: Implication For The Influence Of Habitat Quality On The Species–Area Relationship, Myung-Bok Lee, John P. Carroll

School of Natural Resources: Faculty Publications

Relationships between avian diversity and habitat area are assumed to be positive; however, often little attention has given to how these relationships can be influenced by the habitat structure or quality. In addition, other components of biodiversity, such as functional diversity, are often overlooked in assessing habitat patch value. In the Sandhills Ecoregion of Georgia, USA, we investigated the relationship between avian species richness and functional diversity, forest basal area, and patch size in pine forests using basal area as a surrogate for overstory structure which in turn impacts vegetation structure and determines habitat quality within a patch. We conducted …

An Examination Of Beta Diversity Indices And Their Predictors In Two Large-Scale Systems, Philip Schroeder

Electronic Theses and Dissertations

Biodiversity is what conservation biology was developed to conserve. It is the physical manifestation of life as a concept and, be it for practical or idealistic reasons, all conservationists seek to protect or, in some cases, enhance it. Because of its monolithic importance to the field, much effort has been expended trying to better measure and understand it. Recently, greater attention has been paid to the partition of diversity; the observation that the total diversity of a system (γ) can be broken down into within-site diversity (α) and between-site diversity (β). In particular, it has been noticed that the β …

Existing Ecological Conditions And Management Recommendations For A Portion Of The Chehalem Ridge Nature Park, Oregon, Amanda Pole

Environmental Science and Management Professional Master's Project Reports

Effective land management and habitat restoration work rely on the collection of baseline information regarding the existing conditions of the planning area. Existing conditions assessments can include such information as hydrologic conditions, botanical species assessment, land use issues, wildlife surveys, habitat distribution/quality assessments, etc. This project provides Oregon Metro’s Parks and Nature department with updated information regarding the existing conditions of a portion of the Chehalem Ridge Nature Park (CRNP) as well as recommendations and supplemental maps to aid in future management planning.

Within the ~61-acre project area exist several habitat types: a developing seasonal wetland, riparian forest, Douglas-fir forest, …

A Presence-Absence Survey To Monitor Montezuma Quail In Western Texas, Cristela Gonzalez Sanders, Fidel Hernández, Leonard A. Brennan, Andrew N. Tri, Robert Perez

National Quail Symposium Proceedings

Developing an effective monitoring program for Montezuma quail (Cyrtonyx montezumae) is challenging because the technique must be practical for surveying vast, remote landscapes while accounting for the species’ low detectability. We used call-back surveys within a presence–absence framework to estimate occupancy and detection probability of Montezuma quail and used this information in conjunction with habitat data to develop an estimated probability of occurrence map for the species. We established survey points at 4 sites in western Texas (n = 20–30 points/site) and conducted 5 repeat surveys/season during June–August 2007 and 2008. We documented abiotic conditions (temperature, time …

Do Movement Patterns And Habitat Use Differ Between Optimal- And Suboptimal-Sized Northern Bobwhite Coveys?, Christopher K. Williams, Roger Applegate, Anthony R. Ives

National Quail Symposium Proceedings

The group size of social animals and spatial structure of the environment can affect group behavior and movement decisions. Our objective was to investigate movement patterns and habitat use of northern bobwhite coveys (Colinus virginianus) of different size. Using radiotelemetry, we continuously monitored covey group size, daily movement, and habitat use on 12 independent 259-ha study areas in eastern Kansas, USA, during the winters between 1997 and 2000. We used correlated random walk models and fractal dimension models to determine if covey size affected movement characteristics or habitat selection. Intermediate-sized coveys (9–12 individuals, close to optimal covey size) …

Landscape Genetics Of The California Tiger Salamander: Inferences From Multiple Methods, Samantha Gabrielle Thomas

Masters Theses & Specialist Projects

Landscape genetics is a rapidly growing field of study that compares patterns of gene flow among populations with habitat heterogeneity across a landscape to infer the interaction between dispersal of individuals and their physical environment. Empirical data generated from a landscape genetics study can inform conservation and management strategies, making the field increasing popular. However, concerns have arisen in the literature that the field is expanding faster than the analytic framework that supports it. Multiple methods for generating estimates of the association among habitat types and dispersal (i.e., least-cost paths and resistance surfaces) have been proposed, and there is a …

Larval Rockfish Diversity Abundance Dynamics In Association With A Marine Protected Area In The Southern California Bight, Dustin Chen

Theses

Marine protected areas (MPAs) are areas aimed at protecting natural and cultural resources that are often proposed as a way to alleviate the effects of overfishing on populations of targeted species; these areas have varying degrees of fishing and recreational use restrictions. In order to assess MPA efficacy, it is important to determine the mechanisms by which the presence of MPAs affect reproductive output within and potentially even beyond their boundaries. I attempted to address this through studying the responses of rockfish (Sebastes spp.) larval abundances to the presence of the Cowcod Conservation Areas (CCAs) located within the Southern California …

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 …

Common Carp Disrupt Ecosystem Structure And Function Through Middle-Out Effects, Mark A. Kaemingk, Jeffrey C. Jolley, Craig P. Paukert, David W. Willis, Kjetil Henderson, Richard S. Holland, Greg A. Wanner, Mark L. Lindvall

School of Natural Resources: Faculty Publications

Middle-out effects or a combination of top-down and bottom-up processes create many theoretical and empirical challenges in the realm of trophic ecology. We propose using specific autecology or species trait (i.e. behavioural) information to help explain and understand trophic dynamics that may involve complicated and nonunidirectional trophic interactions. The common carp (Cyprinus carpio) served as our model species for whole-lake observational and experimental studies; four trophic levels were measured to assess common carp-mediated middle-out effects across multiple lakes. We hypothesised that common carp could influence aquatic ecosystems through multiple pathways (i.e. abiotic and biotic foraging, early life feeding, nutrient). Both …

The Influence Of Tree Height On Lidar’S Ability To Accurately Characterize Forest Structure And Spatial Pattern Across Reference Landscapes, Haley L. Wiggins

Graduate Student Theses, Dissertations, & Professional Papers

Successful restoration of degraded forest landscapes requires reference models that adequately capture structural heterogeneity at multiple spatial scales. Field-based methods for assessing variation in forest structure are costly and inherently suffer from limited replication and spatial coverage. LiDAR is a more cost-effective approach for generating landscape-scale data, but it has a limited ability to detect understory trees. Increased understanding of appropriate height cut-offs for trees to be reliably included in LiDAR-based analysis could improve applications of LiDAR to assessments of landscape-scale forest structure. Toward that end, I investigated the effect of varying tree-height criterion (minimum height cutoffs of 6, 9, …

Balancing Stability And Flexibility In Adaptive Governance: An Analysis Of Tools Available In U.S. Environmental Law, Robin Kundis Craig, Ahjond S. Garmestani, Craig R. Allen, Craig Anthony (Tony) Arnold, Hannah E. Birge, Daniel A. Decaro, Alexander K. Fremier, Hannah Gosnell, Edella Schlager

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Adaptive governance must work “on the ground,” that is, it must operate through structures and procedures that the people it governs perceive to be legitimate and fair, as well as incorporating processes and substantive goals that are effective in allowing social-ecological systems (SESs) to adapt to climate change and other impacts. To address the continuing and accelerating alterations that climate change is bringing to SESs, adaptive governance generally will require more flexibility than prior governance institutions have often allowed. However, to function as good governance, adaptive governance must pay real attention to the problem of how to balance this increased …

A Bayesian Method For Assessing Multi-Scale Species-Habitat Relationships, Erica F. Stuber, Lutz F. Gruber, Joseph J. Fontaine

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Context Scientists face several theoretical and methodological challenges in appropriately describing fundamental wildlife-habitat relationships in models. The spatial scales of habitat relationships are often unknown, and are expected to follow a multi-scale hierarchy. Typical frequentist or information theoretic approaches often suffer under collinearity in multiscale studies, fail to converge when models are complex or represent an intractable computational burden when candidate model sets are large.

Objectives Our objective was to implement an automated, Bayesian method for inference on the spatial scales of habitat variables that best predict animal abundance.

Methods We introduce Bayesian latent indicator scale selection (BLISS), a Bayesian …

Swift Foxes In Southwestern South Dakota: Assessing The Current Status Of A Reintroduced Population, Sarah Ann Nevison

Electronic Theses and Dissertations

Swift foxes (Vulpes velox) were reintroduced into Badlands National Park between 2003 and 2006 after being nearly extirpated from South Dakota in the early 1900’s. Genetic analysis provided strong evidence that the reintroduction was successful, but viability analysis indicated the population may be in jeopardy with a high probability of extinction. Recently, the population has declined due to various biotic and abiotic factors (e.g., recent weather patterns, effects of plague [Yersinia pestis], and increased coyote [Canis latrans] numbers). No information on the status of swift foxes has been collected since 2009. Between 2014 and 2016, the objectives of this study …

Complex Vegetation Dynamics At The Fire–Grazing–Drought Nexus, Christine H. Bielski

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

The discipline of ecology long ago moved away from viewing systems as static entities where disturbance processes, environmental stochasticity, and spatiotemporal variability play minor roles in determining ecosystem structure and function. Ecological theory continue to develop frameworks and statistical techniques capable of describing the inherent complexity in natural systems. However, in dealing with the complexity in nature, many applied disciplines have yet to adopt such frameworks or statistical techniques. The objective of this study was bridge the gap between ecological theory and application by using complex systems theory to describe grassland vegetation dynamics at the fire-grazing-drought nexus. Chapters 2 and …

Applications Of Time-Lapse Imagery For Monitoring And Illustrating Ecological Dynamics In A Water-Stressed System, Emma Brinley Buckley

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

Understanding and perceiving the natural world is a key part of management, policy, conservation, and inevitably for our future. Increased demand on natural resources has heightened the importance of documenting ecosystem changes, and knowledge-sharing to foster awareness. The advancement of digital technologies has improved the efficiency of passive monitoring, connectivity among systems, and expanded the potential for innovative and communicative approaches. From technological progression, time-lapse imagery has emerged a valuable tool to capture and depict natural systems. I sought to enhance our understanding of a water-stressed system by analyzing imagery, in addition to integrating images with data visualization to illustrate …

Assessment Of American White Pelican Predation And Reproductive Success Of Walleye In The Tamarac River, Mn, Jake Graham

Biology Graduate Theses

The Tamarac River is a major tributary of the Red Lakes MN, which provides an economically important multispecies fishery. The river experiences spring spawning migrations of northern pike, walleye, and white suckers. However, limited data exists related to reproductive success of fishes in the river. Furthermore, in the previous decade large congregations of American white pelicans (AWPE) have been observed using the Tamarac River as a foraging ground each spring. Assessing reproductive success of fishes in the Tamarac River provides a more holistic understanding of fish ecology in the river and the importance of the Tamarac River to the Red …

Gaur (Bos Gaurus) Abundance, Distribution, And Habitat Use Patterns In Kuiburi National Park, Southwestern Thailand, Supatcharee Tanasarnpaiboon

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

Population status of gaur (Bos gaurus), a wild cattle, in most habitats where they are present, is still unknown. As the use of camera traps in wildlife studies are widespread, I developed photographic individual identification procedures and utilized encounter histories of gaur individuals from camera trap data to estimate gaur abundance and density using the spatially explicit capture-recapture analysis. The study was conducted at Kuiburi National Park, southwestern Thailand, comprised of dry evergreen forest, moist evergreen forest, and man-modified secondary forest during November 2013- January 2015. I conducted 71 direct observations in a savannah-like habitat area to observe …