Life Sciences Commons^™

Ecological Niche Modeling Of Endemic Texas Crayfish Species Under Current Conditions, Sarah A. Burgett

Biology Theses

Crayfish play many important roles in freshwater ecosystems such as ecosystem engineering, bioindicator, and food resource. Even though they are important to ecosystems, they are highly understudied. There has been previous work done on ecological niche modeling on Texas crayfish species, but this study takes it a step further by combining soil, climate, and hydrology variables to model the ecological niches of three endemic species: Procambarus texanus, Procambarus nueces, and Procambarus fayettei. Ecological niche models were created for the three species of interest using the program Maxent. I found that P. texanus and P. fayettei have indistinguishable …

Maximum Entropy Species Distribution Modeling For The Spring Ephemeral Herb Bloodroot (Sanguinaria Canadensis) In Eastern North America, Velan Manivannan

Williams Honors College, Honors Research Projects

The spring ephemeral plant Bloodroot (Sanguinaria canadensis) has a widespread native range in North America, spanning much of the eastern United States and Canada. While its current NatureServe conservation status is designated as ‘secure’ (NatureServe, 2023), its status as a spring ephemeral places it at a heightened risk for climate change-induced phenological mismatch with advancing forest canopy closure. Additionally, under continued anthropogenic climate change, Bloodroot may also experience range shifts or contractions as the edges of its present range warm past physiological thresholds. To determine the potential for range shifts and contractions under future warming, I generated a …

Distribution And Habitat Associations Of The Georgia Satyr (Neonympha Areolatus) In Arkansas, Kristi Patterson

ATU Theses and Dissertations 2021 - Present

The Georgia satyr (Neonympha areolatus) is a small sedentary butterfly that is rare in Arkansas. Currently, the exact locations of this butterfly in Arkansas are unknown, along with the habitat characteristics associated with their presence. In order to determine these unknowns, I completed 104 surveys across seven different wildlife management areas in southern Arkansas. Pollard-Yates transects were conducted at each study site, and weather variables were recorded before each survey. Vegetation surveys were also completed at each site, and where each Georgia satyr was identified. Generalized linear models (GLM) were created to identify what parameters are important for …

The Potential Impact Of Climate Change On The Distributions Of Eleutherodactylus Cystignathoides And E. Planirostris (Anura: Eleutherodactylidae), Rebecca T. Chastain

Theses and Dissertations

Climate change is inducing changes in the distributions of many species, causing range shifts and habitat loss as well as facilitating invasions. It is a broad contributor to global amphibian decline, already causing mass extinctions and extirpations of amphibian populations, a phenomenon which is expected to continue. The understudied direct-developing frog Eleutherodactylus cystignathoides is a notable outlier, having rapidly expanded its distribution in recent years. This is of particular interest given that other eleutherodactylids, such as E. coqui and E. planirostris, have already shown propensity for rapid dispersal and invasion. Originally found in the southernmost tip of …

Documenting The Rapidly Expanding Distribution Of Invasive Ravenna Grass (Tripidium Ravennae) Eastern In Kansas, Rachel A. Styers

Electronic Theses & Dissertations

Invasive species cause significant ecological losses in the United States where they cost approximately $21 billion dollars a year to manage (Fantle-Lepczyk et al., 2022). Early detection of new invasive species, coupled with a rapid response of management efforts, can help to slow the ecological and economic impacts caused by these habitat invaders. Tripidium ravennae (L.) H. Scholz (or Ravenna grass) is a tall, robust, cespitose grass known to occur in Kansas, although its distribution remained poorly documented prior to this study. Given its known invasive tendencies, it has been declared noxious in at least six US states. Coupled with …

Ecogeographical And Micromorphological Differentiation Between Selfing And Outcrossing Sister Species, Alannie-Grace Grant

Doctoral Dissertations

Since their emergence during the Cretaceous period, Angiosperms, or flowering plants, have achieved incredible success on land, colonizing an extensive range of environmental conditions and creating the structure of the Earth’s ecosystems. As they have adapted to these conditions, Angiosperms diverged in their niche breadth, morphological, physiological, biochemical, and phenological traits and evolved into the plant species known today. Some of the diversification within Angiosperm species is attributed to the adaptive evolution of floral traits that facilitate cross-fertilization by attracting and rewarding animal pollinators who transport their pollen or reductions in these traits to maximize self-fertilization.

In this dissertation, I …

Diversidad Y Distribución Espacial Del Género Plagiochila Plagiochilaceae. Marchantiophyta En Colombia, Jonatan Alejandro Yepes Giraldo

Biología

Plagiochila es uno de los géneros más representativos de hepáticas en Colombia. En el país, el género puede encontrarse a lo largo del gradiente altitudinal, con rangos que van desde los 30 a 4300 m, aunque su mayor riqueza se encuentra principalmente en los bosques andino y altoandino, en los que desempeña procesos que aseguran la estabilidad ecológica de los ecosistemas como la regulación del recurso hídrico. En este estudio, utilizamos por primera vez datos del GBIF y del Catálogo en línea de plantas y líquenes de Colombia para investigar aspectos de la diversidad y distribución espacial del género Plagiochila …

Employing Natural History Collections In The Aid Of Conservation: Streamlining An Approach To Model Species Distributions En Masse For The Preservation Of Biodiversity, Alice Fornari

Master's Projects and Capstones

Using species distribution models (SDMs) in Natural History Collections (NHCs) can influence how humans implement conservation changes in flora and fauna communities and ecosystems. Through the use of legacy data (old NHCs and their associated locality/collection information), data correction (background data or pseudo absences added to presence-only data), and the SDM software, Maxent (and its associated geographic information systems or GIS projected models), it has been shown that it is feasible to create a low budget protocol/setup to project the past, present and future of species population changes. This has been done in the past few decades as more collections …

Characterizing Habitat Preference In Three Nearshore Reef-Associated Fishes Through Collaborative Research, Public Data, And Open Source Software, Ian D. Kelmartin

Cal Poly Humboldt theses and projects

Black rockfish (Sebastes melanops), canary rockfish (S. pinniger), and lingcod (Ophidion elongatus) are important species in Northern California’s nearshore recreational and commercial fisheries. These species are associated with nearshore rocky reefs and are among a suite of species intended to benefit from the establishment of the marine protected area (MPA) network along the Northern California Coast in 2012.

Many aspects of the North Coast’s nearshore ecosystem remain poorly studied, including the spatial distribution and habitat associations of nearshore fish species. This study used data collected from Cape Mendocino State Marine Reserve (SMR), Ten Mile …

Spatial Modelling And Wildlife Health Surveillance: A Case Study Of White Nose Syndrome In Ontario, Lauren Yee

Theses and Dissertations (Comprehensive)

Wildlife data is often limited by survey effort, small sample sizes, and spatial biases associated with collection and missing data. These factors can create unique challenges from a surveillance perspective when trying to extract spatial patterns of habitat suitability and disease distributions for conservation and management purposes. This thesis examined data quality from a wildlife health database in the context of spatial analysis of wildlife disease. Spatial analysis of the data to predict habitat suitability of bats and white nose syndrome afflicted bats was examined by using the MaxEnt modelling method. Methods to reduce spatial bias were examined and specific …

Spatially Explicit Model Of Areas Between Suitable Black Bear Habitat In East Texas And Black Bear Populations In Louisiana, Arkansas, And Oklahoma, Caitlin M. Glymph, Christopher Comer, Daniel Scognamillo, Daniel Unger, Yanli Zhang

Electronic Theses and Dissertations

Although black bears (Ursus americanus, Ursus americanus luteolus) were once found throughout the south-central United States, unregulated harvest and habitat loss resulted in severe range retractions and by the beginning of the twentieth century populations in Oklahoma, Louisiana, Texas and Arkansas were nearing extirpation. In response to these losses, translocation programs were initiated in Arkansas (1958-1968 & 2000-2006) and Louisiana (1964-1967 & 2001-2009). These programs successfully restored bears to portions of Louisiana and Arkansas, and, as populations in Arkansas began dispersing, to Oklahoma. In contrast, east Texas remains unoccupied despite the existence of suitable habitat in the region.

To facilitate …

Niche Modeling For The Giant Panda, Ailuropoda Melanoleuca, And The Original Panda, Ailurus Fulgens: Habitat Preferences And Evolutionary Consequences, Lauren M. Lyon

Electronic Theses and Dissertations

The well-known symbol for conservation, the giant panda bear, and the original red panda have been forced into remote habitats due to anthropogenic disturbance, making ecological study difficult. Therefore the first known species distribution model was created to predict the most likely areas of occurrence within the known range of these elusive animals. These models were then projected onto North America and evaluated against existing breeding programs. Additionally, the close proximity of the Gray Fossil Site and the discovery of the most complete fossil red panda specimens in the world allowed ecomorphological comparisons between the modern red panda, Ailurus fulgens …

Integrating Habitat Suitability Modeling And Radio Telemetry To Describe Habitat Use Of The Western Massasaugas, Sistrurus T. Tergeminus, In Texas, Mitchell R. Barazowski

Biology Theses

Habitat suitability modeling using the software package MaxEnt (Phillips, Anderson, & Schapire, 2006) is a popular method for describing the habitat of rare species. MaxEnt uses “presence only” data to develop models; however presence data are highly skewed towards areas of high detection probability and these areas may not represent the full range of habitat use. Thusly, predictions from models developed using only data from areas with high detection probability may not represent all suitable habitat. This study tested the ability of MaxEnt models developed using three different data sets to accurately describe Western Massasauga (Sistrurus t. tergeminus) habitat at …

Predicting Suitable Habitat Decline Of Midwestern United States Amphibians And Quantifying The Consequence Of Declines Using Pond-Breeding Salamanders, Brock Struecker

Master's Theses

With current declines of vertebrate taxa meeting or exceeding those of historic mass extinction events, there is a growing need to investigate the main drivers of declines. Amphibians are perhaps at greatest risk of global climate change and land-use changes than most other vertebrate classes and also have significant roles in ecosystem processes – combined, this creates a cause for concern. I designed a study that would investigate the effects of current and predicted climate change and land-use changes on amphibians using species distribution models and a field study to identify the potential consequences of amphibian species declines by investigating …

Using Plant Functional Traits To Estimate Prairie Restoration Species Composition, Rebecca Schreurs

All Student Theses

Prairie restoration is costly and complex with many methods and types. The use of technology to enhance, economize and simplify prairie restorations is highly desirable, as is the ability to gauge restoration success. The program Maxent allows for an interpretation of data that may facilitate the prediction of plant species composition from species functional traits in different ages of prairie restorations. The inexpensive and diverse nature of Maxent makes it advantageous to restoration managers allowing them to manage expenditures in the field. Maxent determines if specific species trait values and abundance concur with the aggregate trait values of a site. …

Finding The Needle And The Haystack: New Insights Into Locating Bog Turtles (Glyptemys Muhlenbergii) And Their Habitat In The Southeastern United States, Theresa Sonja Margareta Stratmann

All Theses

Because rare and cryptic species can be difficult to locate, distribution maps for these species are often inaccurate or incomplete. Bog Turtles (Glyptemys muhlenbergii) are emblematic of this challenge. In fact, conducting surveys of known, historical, and potential Bog Turtle habitat is a specific need stated in the Bog Turtle Northern Population Recovery Plan and in most Comprehensive Wildlife Conservation Strategies of states within the southern range. Therefore we examined ways to better locate Bog Turtle habitat and Bog Turtles within that habitat. First we determined a detection probability for a standardized trapping method so we could effectively survey for …

"Model Complexity And Variable Selection In Maxent Niche Models: Analyses For Rodents In Madagascar", Peter Galante

Dissertations and Theses

Ecological niche models (ENMs) characterize the relationship between localities where a species is known to occur and the abiotic characteristics of these regions. While widely used, ENMs remain subject to several outstanding issues, including those related to model complexity and violation of modeling assumptions (e.g., representative sampling). Critical in resolving these issues is a better understanding of the effectiveness of model selection techniques. Here, I compare two strategies for optimizing ENMs: an information-criterion approach (AICc) and a sequential approach that assesses model performance on withheld data. I do so for a single species using two datasets, one with all available …

Fern Community Reassembly In Secondary Forests Of Puerto Rico: Predictors, Complexity, And Niche Model Assessment, Thomas J. Schmidt

Masters Theses

Approximately 94% of Puerto Rico’s forests were converted into agricultural systems by 1950. Since then, extensive abandonment of agricultural land has resulted in a considerable amount of forest regeneration throughout the main island. Ferns are a major non-woody component of oceanic, tropical island forests comprising up to seventy percent of the flora. Consequently, the composition and community structure of ferns may be indicative of the relative richness of these secondary forests. I used Maximum Entropy (Maxent), a widely-used mathematical tool for distinguishing suitable versus unsuitable fern niche space, along with ENMTools, a tool that assists Maxent with proper model selection, …

Modeling Habitat Use Of A Fringe Greater Sage-Grouse Population At Multiple Spatial Scales, Anya Cheyenne Burnett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Greater sage-grouse (Centrocercus urophasianus; hereafter sage-grouse) are a prominent bird species of sagebrush-dominated landscapes across the western United States. Over the past 15 years, sage-grouse have gained international attention due to decreasing population trends despite management efforts. In 2010 the U.S. Fish and Wildlife Service designated this species as warranted for listing under the Endangered Species Act, but the listing was precluded by other species at higher conservation risk. Habitat loss, degradation, and fragmentation have been implicated as primary sources of declines in sage-grouse distribution and abundance. The Bald Hills population in southwestern Utah occupies an area with …

Improving Model Performance For Invasive Plant Species Distribution Using Global-Scale Presence-Only Data: Parameterization And Data Quality, Feng Yu

Open Access Theses

Invasive species have significant ecological and economic impacts. To control species' invasion, risk assessment provides the most essential information for identification and evaluation of the potential risk of the invasive species, especially in their early invasion stages. Species distribution models (SDMs) is the foundation for risk assessment, in terms of both the practical and theoretical interest in our understanding of species invasion process. SDMs contribute to the proactive invasion management and the test of ecological or biogeographical hypotheses about species distributions in relation to their environment.

However, modeling of invasive species at large spatial scale (i.e., cross-continental) is rarely discussed. …

A Comprehensive Research Framework For Geographic Parthenogenesis In Whiptail Lizards (Genus Aspidoscelis), Adam Leland

UNLV Theses, Dissertations, Professional Papers, and Capstones

One of the most compelling topics in biology has been the ubiquity of sexual reproduction in living organisms. Because the ecological and evolutionary advantages of sex are well founded, those organisms that reproduce asexually remain enigmatic. Parthenogenesis, the clonal reproduction of an all-female species without the need for males, is a relatively common form of asexual reproduction in vertebrates, and has been subject of numerous academic investigations. Many parthenogenic organisms also share aspects of their geographic distributions, such as inhabiting higher latitudes, higher altitudes, islands or island-like habitats, xeric environments, and marginal, disturbed or ecotonal habitats relative to their sexual …

The Effect Of The Study Region On Gis Models Of Species Geographic Distributions And Estimates Of Niche Evolution; Preliminary Tests With Montane Rodents (Genus Nephelomys) In Venezuela, Ali Raza

Dissertations and Theses

Various niche-based techniques exist to model a species' potential geographic distribution in a Geographic Information Systems (GIS) framework. These models compare the environmental conditions of localities of a species' occurrence versus those of the overall study region. In addition to uses in areas such as macroecology and conservation biology, this approach has been applied recently to studies of niche evolution and historical biogeography. Definition of the study region is critical for all of these applications but has not been addressed previously. Here, I examine the effect of changes in the extent of the study region on potential distribution models of …