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Full-Text Articles in Biology

Winter Survival Strategies Of Benthic Invertebrates In Temporary Habitats In A Northern Minnesota Lake, Cal Oldenburg Jan 2014

Winter Survival Strategies Of Benthic Invertebrates In Temporary Habitats In A Northern Minnesota Lake, Cal Oldenburg

Journal of Earth and Life Science

During the winter months in the northern hemisphere, above 40 degrees latitude, a freezing event occurs that can last several months. Some lakes may have large portions of the shallow littoral zone frozen completely solid down into the sediments. Invertebrates affected by these events have developed survival strategies to cope with the harsh environment. The two main strategies for invertebrates in these areas are to either migrate to a different area and recolonize the original area when it becomes available again, or to burrow into the sediments and withstand the freezing. A 1- month study took place on Lake Bemidji …


Genetic Variation, Local Adaptation And Population Structure In North American Red Oak Species, Quercus Rubra L. And Q. Ellipsoidalis E. J. Hill, Jennifer F. Lind-Riehl Jan 2014

Genetic Variation, Local Adaptation And Population Structure In North American Red Oak Species, Quercus Rubra L. And Q. Ellipsoidalis E. J. Hill, Jennifer F. Lind-Riehl

Dissertations, Master's Theses and Master's Reports - Open

Forest trees, like oaks, rely on high levels of genetic variation to adapt to varying environmental conditions. Thus, genetic variation and its distribution are important for the long-term survival and adaptability of oak populations. Climate change is projected to lead to increased drought and fire events as well as a northward migration of tree species, including oaks. Additionally, decline in oak regeneration has become increasingly concerning since it may lead to decreased gene flow and increased inbreeding levels. This will in turn lead to lowered levels of genetic diversity, negatively affecting the growth and survival of populations. At the same …


Effects Of Toxic Cyanobacteria (Microcystis Aeruginosa) On The Feeding And Reproduction Ecology Of The Copepod Eurytemora Affinis From Green Bay, Lake Michigan, Nicholas J. Barrett Jan 2014

Effects Of Toxic Cyanobacteria (Microcystis Aeruginosa) On The Feeding And Reproduction Ecology Of The Copepod Eurytemora Affinis From Green Bay, Lake Michigan, Nicholas J. Barrett

Lawrence University Honors Projects

Toxic Cyanobacteria is known to be a bad food source to consumers as well as a main contributor to harmful algal blooms. This study investigates the feeding relationship between an invasive copepod in the Great Lakes system, Eurytemora affinis, and a toxic strain of cyanobacteria, Microcystis aeruginosa. E.affinis has been shown to feed on toxic cyanobacteria. By measuring the filtering rate, ingestion rate, egg production and offspring size between three different food conditions, we hope to gain insight into the effects of toxic cyanobacteria on the feeding and reproduction of this copepod. Food sources include a good green algal …


Remediation Of Tetracycline From Water Sources Using Vetiver Grass (Chrysopogon Zizanioides L. Nash) And Tetracycline-Tolerant Root-Associated Bacteria, Aparupa Sengupta Jan 2014

Remediation Of Tetracycline From Water Sources Using Vetiver Grass (Chrysopogon Zizanioides L. Nash) And Tetracycline-Tolerant Root-Associated Bacteria, Aparupa Sengupta

Dissertations, Master's Theses and Master's Reports - Open

Antibiotics are emerging contaminants worldwide. Due to insufficient policy regulations, public awareness, and the constant exposure of the environment to antibiotic sources has created a major environmental concern. Wastewater treatment plants (WWTP) are not equipped to filter-out these compounds before the discharge of the disinfected effluent into water sources (e.g., lakes and streams) and current available technologies are not equipped to remediate these compounds from environmental sources. Hence, the challenge remains to establish a biological system to remove these antibiotics from wastewater. An invitro hydroponic remediation system was developed using vetiver grass (Chrysopogon zizanioides L. Nash) to remediate tetracycline …


Denitrification In Soils: From Genes To Environmental Outcomes, Jianqiu Zheng Jan 2014

Denitrification In Soils: From Genes To Environmental Outcomes, Jianqiu Zheng

Dissertations, Master's Theses and Master's Reports - Open

Denitrification is an important process of global nitrogen cycle as it removes reactive nitrogen from the biosphere, and acts as the primary source of nitrous oxide (N2O). This thesis seeks to gain better understanding of the biogeochemistry of denitrification by investigating the process from four different aspects: genetic basis, enzymatic kinetics, environmental interactions, and environmental consequences. Laboratory and field experiments were combined with modeling efforts to unravel the complexity of denitrification process under microbiological and environmental controls.

Dynamics of denitrification products observed in laboratory experiments revealed an important role of constitutive denitrification enzymes, whose presence were further confirmed …


Characterization Of A Plant Gene Family Expanded In Glycine Max, Lisa Snoderly-Foster Jan 2014

Characterization Of A Plant Gene Family Expanded In Glycine Max, Lisa Snoderly-Foster

Masters Theses

"Glycine max, commonly named the cultivated soybean, is one of the oldest and most important food crops in the world. The study of the G. max genome provides valuable insight into the molecular mechanisms that govern its reproduction and environmental responsiveness, key factors in maximizing crop yield. Since the complete sequencing of the genome in 2010, the analysis has become faster and easier, especially with the development of numerous web-based, publically accessible bioinformatics tools.

This research effort utilizes these tools to characterize a small, unannotated G. max gene family. Although no definitive evidence was uncovered for the production of a …


Investigation Of Angiogenic Effects Of Bioactive Borate Glass Microfibers And Beads In A Rodent Model, Richard Jeffrey Watters Jan 2014

Investigation Of Angiogenic Effects Of Bioactive Borate Glass Microfibers And Beads In A Rodent Model, Richard Jeffrey Watters

Masters Theses

"The primary objective of this research project was to evaluate the effects of three different compositions of bioactive glass microfibers (45S5, 13-93B3, and 13-93B3Cu) and bioactive glass beads (13-93, 13-93B3, and 13-93B3Cu) on angiogenesis in subcutaneous tissue in the SKH1 'hairless' mouse. Microvascular responses to the bioactive glass implants were investigated via three experimental approaches: noninvasive vital imaging of microvasculature in dorsal skin windows; quantitative histomorphometry of microvascular densities; and quantitative PCR measurements of mRNA expression of pro-angiogenic cytokines VEGF and FGF-2. The live imaging of dorsal skin window preparations in the hairless SKH1 showed the formation of a halo-like …


Dephosphorylation Of Iqg1 By Cdc14 Temporally Regulates Actin Ring Formation, Daniel Patrick Miller Jan 2014

Dephosphorylation Of Iqg1 By Cdc14 Temporally Regulates Actin Ring Formation, Daniel Patrick Miller

Masters Theses

"Cytokinesis is the final step in cell division when the cell separates the cytoplasm by contracting a ring composed of filamentous actin (F-actin) and type II myosin. Iqg1, an IQGAP family member, is an essential scaffolding protein in budding yeast (S. cerevisiae) required for actin recruitment to, and contraction of, the actomyosin ring. Actin is recruited by the calponin homology domain (CHD) in anaphase after Iqg1 is localized to the bud neck. Consensus sites for the cyclin-dependent kinase (CDK) Cdc28 were identified flanking the CHD. This led us to the hypothesis that phosphorylation of Iqg1 by Cdc28 negatively regulates actin …


Ecology Of A Declining Great Plains Fish, Fundulus Sciadicus, In The Missouri Ozarks, Gregory Travis Thompson Jan 2014

Ecology Of A Declining Great Plains Fish, Fundulus Sciadicus, In The Missouri Ozarks, Gregory Travis Thompson

Masters Theses

"Anthropogenic habitat disturbances are of growing concern due to their impacts on native biota, especially in freshwater ecosystems. Damming, channelization, urbanization, wetland draining, and non-native fish introductions all play large roles in habitat homogeneity, fragmentation, and species competition. This has negative effects on native fish and invertebrate species. In the Midwestern United States, the plains topminnow (Fundulus sciadicus) has been declining across its range, to the point of becoming a species of special concern in Missouri. This is possibly due to a combination of the above anthropogenic habitat disturbances. To better understand the ecology of the plains topminnow …


Spingolipid Metabolism In A Reptillian Protozoan, Entamoeba Invadens, Duran Dogan Debons Jan 2014

Spingolipid Metabolism In A Reptillian Protozoan, Entamoeba Invadens, Duran Dogan Debons

Open Access Theses & Dissertations

Entamoeba invadens (hereinafter E. invadens) is an anaerobic parasitic protozoan that can be found in water and soil. Although the host organisms for this parasite are snakes, lizards, and other reptile species, the parasite is morphologically identical to Entamoeba histolytica, a causative agent of human amebiasis. Entamoeba inavdens exists in two morphological forms--(1) a replicative trophozoite, and (2) a relatively dormant cyst. While the transformation of cyst to trophozoites (called "excystation") takes place in the stomach, the differentiation of trophozoites to cyst (known as "encystation"), occurs in the small intestine. Unlike the cyst, a trophozoite is unable to survive …


"Mining" For A Reference Condition In Southern West Virginia Streams, Matthew Rouch Jan 2014

"Mining" For A Reference Condition In Southern West Virginia Streams, Matthew Rouch

Theses and Dissertations

Quarterly samples were used to estimate assemblage-level (all species combined) fish production within three minimally-impacted, southern West Virginia streams. The total annual fish production estimate was highest in Slaunch Fork (37.52 kg∙ha-1∙y-1), a tributary of the Tug Fork River, and lowest in Cabin Creek (10.59 kg∙ha-1∙y-1), a Guyandotte River tributary. Creek Chub Semotilus atromaculatus, Mottled Sculpin Cottus bairdii and Blacknose Dace Rhinicthys atratulus were the most abundant species among sites, accounting for >90% of all sampled individuals. Reference condition criteria were also selected and metrics calculated for each of the three …


Modelling Cholera In Periodic Environments, Drew Posny, Jin Wang Jan 2014

Modelling Cholera In Periodic Environments, Drew Posny, Jin Wang

Mathematics & Statistics Faculty Publications

We propose a deterministic compartmental model for cholera dynamics in periodic environments. The model incorporates seasonal variation into a general formulation for the incidence (or, force of infection) and the pathogen concentration. The basic reproduction number of the periodic model is derived, based on which a careful analysis is conducted on the epidemic and endemic dynamics of cholera. Several specific examples are presented to demonstrate this general model, and numerical simulation results are used to validate the analytical prediction.


The Effects That Liquid And Solid Cattle Manure Have On The Water Quality Of Drainage Ditches In Putnam County, Ohio, Janelle Horstman Jan 2014

The Effects That Liquid And Solid Cattle Manure Have On The Water Quality Of Drainage Ditches In Putnam County, Ohio, Janelle Horstman

Honors Projects

Lake Erie has experienced harmful algal blooms with increased frequency since the mid-1990s due to excess nutrients from Rivers, such as the Maumee River, and largely agricultural watersheds. Nonpoint source pollution from agriculture contributes to eutrophication, algal blooms, and the degradation of water quality. This creates stress on aquatic fauna, reduced aesthetic quality, odor, and limits of the water for usage of drinking, recreation, and industry. This research paper asks what the contributions of having access to manure application records, soil records, and information about antibiotics have on what is known about manure management and antibiotic resistance, which has been …


Closing The Knowing-Doing Gap In Invasive Plant Management: Accessibility And Interdisciplinarity Of Scientific Research, Virginia Matzek, Justin Covino, Jennifer L. Funk, Martin Saunders Jan 2014

Closing The Knowing-Doing Gap In Invasive Plant Management: Accessibility And Interdisciplinarity Of Scientific Research, Virginia Matzek, Justin Covino, Jennifer L. Funk, Martin Saunders

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Like many conservation disciplines, invasion biology may suffer from a knowing-doing gap, where scientific research fails to inform management actions. We surveyed California resource managers to evaluate engagement with scientific research and to identify research priorities. We examined managers' access to information, judgment of the usefulness of existing research, ability to generate scientific information, and priorities for future research. We found that practitioners rely on their own experience, and largely do not read the peer-reviewed literature, which they regard as only moderately useful. Less than half of managers who do research carry out experiments conforming to the norms of hypothesis …


Effects Of Salinity And Dissolved Organic Matter On Cu Toxicity To Americamysis Bahia In Estuarine Environments, Rabia Nasir Jan 2014

Effects Of Salinity And Dissolved Organic Matter On Cu Toxicity To Americamysis Bahia In Estuarine Environments, Rabia Nasir

Theses and Dissertations (Comprehensive)

As salinity increases the geochemical speciation of Cu is altered as a result of organic/inorganic complexation/competition. Such salinity changes may further challenge the osmoregulatory capabilities of euryhaline organisms. This chemical-biological interaction complicates the understanding of the impacts of Cu in estuarine waters. Dissolved organic matter (DOM) has been widely established to be an important modifier of Cu toxicity in freshwaters however its effectiveness in modulating Cu toxicity across the range of salinities that occur in estuarine conditions has not been studied in a systematic manner. Site to site differences in DOM quality with respect to the potential for toxicity mitigation …


Development And Application Of A Gis-Based Long Island Sound Eelgrass Habitat Suitability Index Model, Jamie M.P. Vaudrey, Justin Eddings, Christopher Pickerell, Lorne Brousseau, Charles Yarish Dec 2013

Development And Application Of A Gis-Based Long Island Sound Eelgrass Habitat Suitability Index Model, Jamie M.P. Vaudrey, Justin Eddings, Christopher Pickerell, Lorne Brousseau, Charles Yarish

Department of Marine Sciences

The primary objectives of the Eelgrass Habitat Suitability Index Model (EHSI Model) are to assist in the evaluation of sites being considered for eelgrass restoration efforts in the Long Island Sound (LIS) area and to identify areas where water quality issues reduce or eliminate the potential for natural eelgrass colonization. To achieve this goal, geospatial processing of data available from the Long Island Sound area was conducted using ArcGIS v10.0 including the 3D Analyst and Spatial Analyst extensions. The result is a series of maps presented in this report and a GIS-based model available for users to interact with the …


Assessing Growth Response To Climate Controls In A Great Basin Artemisia Tridentata Plant Community, Lorenzo F. Apodaca Dec 2013

Assessing Growth Response To Climate Controls In A Great Basin Artemisia Tridentata Plant Community, Lorenzo F. Apodaca

UNLV Theses, Dissertations, Professional Papers, and Capstones

An assessment of the growth response of key vegetative species to climatic variability is vital to identifying possible local impacts on ecosystems faced with imminent climate change. With current climate projections in Nevada predicting a shift to an even more arid climate with greater year-to-year variability, the imperative exists to identify the effects of specific climatic controls on plant growth and to research methods to assess large-scale vegetative changes, especially in more remote areas where readily available data sets may be lacking. This study utilized annual growth ring indices constructed from big sagebrush (Artemisia tridentatassp.tridentata) stems collected in Spring Valley, …


A Survey Of Heavy Metals In Water, Soil And The Surrounding Plants In The Lower Rio Grande Valley, Erving W. Morelius Dec 2013

A Survey Of Heavy Metals In Water, Soil And The Surrounding Plants In The Lower Rio Grande Valley, Erving W. Morelius

Theses and Dissertations - UTB/UTPA

Heavy metal pollution of the environment in recent years has become a major issue of importance for both human and environmental health. Samples were investigated for the potential pollution of the area as it is a vital produce producing area. During the study plant, soil and water samples were collected from the Donna Reservoir and Canal System to test the concentration of various heavy metals. The heavy metals tested included both potentially toxic and micronutrients in the samples which included arsenic, cadmium, chromium, copper, iron, lead, nickel and sulfur. During the study, a sixty day sampling period was used to …


Evaluating The Efficacy Of Land Snail Survey Techniques In Hawaii: Implications For Conservation Throughout The Pacific, Torsten Durkan, Norine Yeung, Wallace Meyer, Kenneth Hayes, Robert Cowie Nov 2013

Evaluating The Efficacy Of Land Snail Survey Techniques In Hawaii: Implications For Conservation Throughout The Pacific, Torsten Durkan, Norine Yeung, Wallace Meyer, Kenneth Hayes, Robert Cowie

Department of Biology Faculty Publications

Terrestrial micromolluscs (snails with an adult maximum shell dimension <5 mm) constitute a considerable proportion of the land snail fauna of the Pacific. However, micromolluscs are often underestimated in biological surveys because of size bias. It has been argued that visual searches are preferable on Pacific islands because: (1) size biases are limited based on the understanding that most native Pacific island land snails are very small, and (2) amount of labor is less than other methods such as soil surveys and adequate for inventory purposes (though not for abundance assessments). To test whether visual surveys and soil surveys were accurately recording all taxa, land snail inventories were completed in three forest reserves (5 sampling sites in each) on the island of Oahu, Hawaii. Visual surveys involved 30-min visual search in a 10 m2 site; soil surveys involved sieving leaf litter and topsoil from four 0.3 m2 quadrats and extracting snails with the aid of a microscope. The data indicate a size and microhabitat bias associated with both techniques. Visual surveys consistently collected large arboreal and litter-dwelling species but missed a significant portion of micromolluscs, while soil surveys collected micromolluscs but missed larger snails. Because of such biases, employing both methods is critical for collecting all taxa at a survey location. As such, we recommend that future land snail surveys on Pacific Islands incorporate both survey techniques. Obtaining a complete inventory is critical if we are to understand species distributions and patterns of diversity and make well-informed conservation recommendations.


Acquisition Of An Electrochemical System Instrument For The Development Of Sensors, Elmer-Rico E. Mojico Oct 2013

Acquisition Of An Electrochemical System Instrument For The Development Of Sensors, Elmer-Rico E. Mojico

Cornerstone 1 Reports : Expansion and Enhancements of the Thinkfinity Platform

No abstract provided.


A Multi-Scale Analysis Of The Effects Of Local- And Landscape-Level Variables On Nuthatch Occupancy And Distribution, Jesse Wood Oct 2013

A Multi-Scale Analysis Of The Effects Of Local- And Landscape-Level Variables On Nuthatch Occupancy And Distribution, Jesse Wood

Earth and Environmental Sciences Presentations

The objectives of this study are to conduct a multi-scale analysis of the effects of habitat variables on Brownheaded Nuthatch (S. pusilla) occupancy and spatial distribution in the greater Greenville area of South Carolina. By understanding the local- and landscape-drivers of an ecologically sensitive species, we can build a predictive model of species occurrence and contribute to regional conservation efforts of both habitat and biodiversity.


Upland Habitat Quality And Historic Landscape Composition Influence Genetic Variation Of A Pond-Breeding Salamander, Stephen C. Richter, Steve J. Price, Chelsea S. Kross, Jeremiah R. Alexander, Michael E. Dorcas Sep 2013

Upland Habitat Quality And Historic Landscape Composition Influence Genetic Variation Of A Pond-Breeding Salamander, Stephen C. Richter, Steve J. Price, Chelsea S. Kross, Jeremiah R. Alexander, Michael E. Dorcas

Forestry and Natural Resources Faculty Publications

Understanding the temporal and spatial scale at which habitat alteration impacts populations is important for conservation and management. Amphibians have declined more than other vertebrates, and pond-breeding species are particularly susceptible to habitat loss and fragmentation because they have terrestrial and aquatic life stages. One approach to management of pond-breeding species is protection of core upland habitat surrounding the breeding pond. We used genetic variation as an indicator of population status in a common amphibian species, spotted salamanders (Ambystoma maculatum), to determine how amount of suitable upland habitat relates to population status in the greater Charlotte, North Carolina, …


Incorporating Satellite Derived Cloud Climatologies To Improve High Resolution Interpolation Of Daily Precipitation., Adam M. Wilson, Benoit Parmentier, Brian Mcgill, Rob Guralnick, Walter Jetz Sep 2013

Incorporating Satellite Derived Cloud Climatologies To Improve High Resolution Interpolation Of Daily Precipitation., Adam M. Wilson, Benoit Parmentier, Brian Mcgill, Rob Guralnick, Walter Jetz

Yale Day of Data

Conservation of biodiversity demands comprehension of evolutionary and ecological patterns and processes that occur over vast spatial and temporal scales. A central goal of ecology is to understand the factors that control the spatial distribution of species and this has become even more important in the face of climate change. However, at global scales there can be enormous uncertainty in environmental data used to model species distributions. Even ‘simple’ metrics such as mean annual precipitation are difficult to estimate in areas with few weather stations and available data sets do not quantify uncertainty in these surfaces. We are developing a …


Climate Change And Plant Demography In The Sagebrush Steppe, Aldo Compagnoni Jul 2013

Climate Change And Plant Demography In The Sagebrush Steppe, Aldo Compagnoni

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.


Using Economic Instruments To Develop Effective Management Of Invasive Species: Insights From A Bioeconomic Model, Shana M. Mcdermott, Rebecca E. Irwin, Brad W. Taylor Jul 2013

Using Economic Instruments To Develop Effective Management Of Invasive Species: Insights From A Bioeconomic Model, Shana M. Mcdermott, Rebecca E. Irwin, Brad W. Taylor

Dartmouth Scholarship

Economic growth is recognized as an important factor associated with species invasions. Consequently, there is increasing need to develop solutions that combine economics and ecology to inform invasive species management. We developed a model combining economic, ecological, and sociological factors to assess the degree to which economic policies can be used to control invasive plants. Because invasive plants often spread across numerous properties, we explored whether property owners should manage invaders cooperatively as a group by incorporating the negative effects of invader spread in management decisions (collective management) or independently, whereby the negative effects of invasive plant spread are ignored …


Biochemical, Nutrient And Inhibitory Characteristics Of Streptomyces Cultured From A Hypersaline Estuary, The Laguna Madre (Texas), Luis E. Espinoza, Anita L. Davelos Baines, Kristine L. Lowe May 2013

Biochemical, Nutrient And Inhibitory Characteristics Of Streptomyces Cultured From A Hypersaline Estuary, The Laguna Madre (Texas), Luis E. Espinoza, Anita L. Davelos Baines, Kristine L. Lowe

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Streptomyces are common soil bacteria that produce secondary metabolites, including several antibiotics; however, the characteristics of marine Streptomyces are largely unknown. Sediment samples were taken from 3 sites in the Laguna Madre to isolate marine Streptomyces. Sediment was diluted, spread onto synthetic seawater media to estimate the total bacterial density of the samples and spread onto starch casein agar to isolate Streptomyces. Isolated Streptomyces were tested for salinity tolerance and optimal growth pH. Isolates were assayed using API 20E® test strips and BIOLOG™ plates to construct biochemical profiles and assess nutrient utilization abilities of the bacteria, respectively. Individual Streptomyces were …


Factors Influencing Nest Site Selection By Wood Turtles (Glyptemys Insculpta) In An Altered Forest Landscape, Ellery Ruther May 2013

Factors Influencing Nest Site Selection By Wood Turtles (Glyptemys Insculpta) In An Altered Forest Landscape, Ellery Ruther

Theses & Honors Papers

There have been many studies concerning wood turtle (Glyptemys insculpta) nest site selection, including studies that evaluate nest site conditions when stream sand banks are not available. However, because of the unique landscape at our study site (high gradient, first order streams) and rapidly diminishing wood turtle populations in Virginia, I am evaluating wood turtle nest site selection. Nine physiographic and vegetative characteristics from nest, positive, negative-one and negative-two control locations were evaluated using binomial generalized linear models and then best fit models were chosen using Akaike's Information Criterion (AIC). It was found that in lieu of typical stream …


Study Of Genes Relating To Degradation Of Aromatic Compounds And Carbon Metabolism In Mycobacterium Sp. Strain Kms, Chun Zhang May 2013

Study Of Genes Relating To Degradation Of Aromatic Compounds And Carbon Metabolism In Mycobacterium Sp. Strain Kms, Chun Zhang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Polycyclic aromatic hydrocarbons are produced from incomplete combustion of organic materials by human or natural activities. These polycyclic aromatic hydrocarbons are classified as pollutants because of their toxic, mutagenic, and carcinogenic characteristics. Mycobacterium sp. strain KMS, isolated from a contaminated soil, grows on the model polycyclic aromatic hydrocarbon, pyrene, with its degradation to water and carbon dioxide. This study locates genes on the chromosome and plasmids of isolate KMS relating to pyrene degradation, elucidates the influence of other carbon sources available in the habitats of isolate KMS on degradation of pyrene, and deduces possible metabolic pathways used by isolate …


Dispersal Ecology Of Desert Mosses Along Gradients Of Elevation, Wildfire Disturbance And Local Niche, Robert Joseph Smith May 2013

Dispersal Ecology Of Desert Mosses Along Gradients Of Elevation, Wildfire Disturbance And Local Niche, Robert Joseph Smith

UNLV Theses, Dissertations, Professional Papers, and Capstones

Much of the variation in plant communities can be explained by the dispersal of individuals across landscapes, an ecological process that contributes to clinal variation, post-disturbance recovery and habitat occupancy. The role of dispersal is of particular concern for Mojave Desert plant communities that may not be able to tolerate recent departures from historical fire regimes. The aim of this thesis was to infer how dispersal is reflected by patterns of diversity in disturbed and undisturbed bryophyte communities in the Spring Mountains of southern Nevada. Chapter 2 presents an examination of sub-surface bryophyte communities (propagule "soil-banks") along a 1400 m …


Effects Of Environmental Variables On The Reproduction Of Quagga Mussels (Dreissena Rostriformis Bugensis) In Lake Mead, Nv/Az, Richard Steven Ianniello May 2013

Effects Of Environmental Variables On The Reproduction Of Quagga Mussels (Dreissena Rostriformis Bugensis) In Lake Mead, Nv/Az, Richard Steven Ianniello

UNLV Theses, Dissertations, Professional Papers, and Capstones

In 2007, quagga mussels (Dreissena rostriformis bugensis) were found in Lake Mead and have spread downstream on the Colorado River and to other lakes and reservoirs in the Southwestern United States. The quagga mussel's extremely quick colonization of Lake Mead and annual veliger abundance trends provide evidence that the quagga mussels in the Southwest have different reproductive behavior than in previous habitats. This study is one of the first to specifically examine quagga mussel reproduction in the Southwest and examines how quagga mussel reproduction varies at sites known to have different temperatures and other environmental variables resulting from the input …