Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Ecology and Evolutionary Biology

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 13141 - 13170 of 19722

Full-Text Articles in Entire DC Network

Plant-Mediated Effects On Microbial Diversity In Mesocosms Of An Oligotrophic Bog, Karl J. Romanowicz Iv Jan 2013

Plant-Mediated Effects On Microbial Diversity In Mesocosms Of An Oligotrophic Bog, Karl J. Romanowicz Iv

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

Globally, peatlands occupy a small portion of terrestrial land area but contain up to one-third of all soil organic carbon. This carbon pool is vulnerable to increased decomposition under projected climate change scenarios but little is known about how plant functional groups will influence microbial communities responsible for regulating carbon cycling processes. Here we examined initial shifts in microbial community structure within two sampling depths under plant functional group manipulations in mesocosms of an oligotrophic bog. Microbial community composition for bacteria and archaea was characterized using targeted 16S rRNA Illumina gene sequencing. We found statistically distinct spatial patterns between the …


Evaluation And Monitoring Of Ash (Fraxinus Spp.) Tolerant To Long-Term Emerald Ash Borer (Agrilus Planipennis [Coleoptera: Buprestidae]) Exposure, Kathryn G. Hietala Jan 2013

Evaluation And Monitoring Of Ash (Fraxinus Spp.) Tolerant To Long-Term Emerald Ash Borer (Agrilus Planipennis [Coleoptera: Buprestidae]) Exposure, Kathryn G. Hietala

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

Invasive insects that successfully establish in introduced areas can significantly alter natural communities. These pests require specific establishment criteria (e.g. host suitability) that, when known, can help quantify potential damage to infested areas. Emerald ash borer (Agrilus planipennis [Coleoptera: Buprestidae]) is an invasive phloem-feeding pest which is responsible for the death of millions of ash trees (Fraxinus spp. L.). Over 200 surviving ash trees were previously identified in the Huron-Clinton Metroparks located in southeast Michigan. Trees were assessed over a four year period and a hierarchical cluster analysis was performed on dieback, vigor, and presence of signs and …


Chapter 1 - Field Taxonomy And Collection Methods, Janice M. Glime Jan 2013

Chapter 1 - Field Taxonomy And Collection Methods, Janice M. Glime

Bryophyte Ecology Volume 3: Methods

Explore the contents of Bryophyte Ecology, Volume 3, Chapter 1 - field Taxonomy and Collection Methods by clicking the link above. For the Contents section of this ebook, as well as Volumes 1 through 5, please visit the Bryophyte Ecology Main Page.

Use CTRL+F to easily search within PDF files.

Ebook sponsored by Michigan Technological University and the International Association of Bryologists.


Chapter 5 - Construction, Janice M. Glime Jan 2013

Chapter 5 - Construction, Janice M. Glime

Bryophyte Ecology Volume 5: Uses

Explore the contents of Bryophyte Ecology, Volume 5, Chapter 5 - Construction by clicking the link above. For the Contents section of this ebook, as well as Volumes 1 through 5, please visit the Bryophyte Ecology Main Page.

Use CTRL+F to easily search within PDF files.

Ebook sponsored by Michigan Technological University and the International Association of Bryologists.


Chapter 1 - Household And Personal Uses, Janice M. Glime Jan 2013

Chapter 1 - Household And Personal Uses, Janice M. Glime

Bryophyte Ecology Volume 5: Uses

Explore the contents of Bryophyte Ecology, Volume 5, Chapter 1 - Household and Personal Uses by clicking the link above. For the Contents section of this ebook, as well as Volumes 1 through 5, please visit the Bryophyte Ecology Main Page.

Use CTRL+F to easily search within PDF files.

Ebook sponsored by Michigan Technological University and the International Association of Bryologists.


Chapter 3 - Fine Arts, Janice M. Glime Jan 2013

Chapter 3 - Fine Arts, Janice M. Glime

Bryophyte Ecology Volume 5: Uses

Explore the contents of Bryophyte Ecology, Volume 5, Chapter 3 - Fine Arts by clicking the links above. For the Contents section of this ebook, as well as Volumes 1 through 5, please visit the Bryophyte Ecology Main Page.

Use CTRL+F to easily search within PDF files.

Ebook sponsored by Michigan Technological University and the International Association of Bryologists.


Effects Of Dissolved Nutrient Ratios And Concentrations On Litter-Associated Microbial Activity In Streamside Channels, Timothy Burns Jan 2013

Effects Of Dissolved Nutrient Ratios And Concentrations On Litter-Associated Microbial Activity In Streamside Channels, Timothy Burns

Electronic Theses and Dissertations

Heterotrophic consumers, such as microorganisms and invertebrates, play a fundamental role in the flow of carbon and energy in streams. The effects of dissolved nutrient concentrations, and especially ratios, on litter—associated microorganisms and decomposition rates of detritus are poorly understood. This study addressed the responses of heterotrophic microbes to a wide range of concentrations and ratios of dissolved inorganic nitrogen (N) and phosphorus (P) in streamside channels simulating headwater streams. Two main questions were: (1) do microbial parameters and litter decomposition rates peak at a dissolved N:P ratio that approaches the nutrient ratio of microbial biomass, and (2) does microbial …


Impact Of Macroconsumers On Leaf Breakdown And Detritivores In Wet And Dry Wetlands On A Southeastern Us Coastal Plain Floodplain, Bryanna Libby Jan 2013

Impact Of Macroconsumers On Leaf Breakdown And Detritivores In Wet And Dry Wetlands On A Southeastern Us Coastal Plain Floodplain, Bryanna Libby

Electronic Theses and Dissertations

Interactions among macroconsumers (predators and large omnivores) and detritus breakdown are poorly understood on river floodplains. I evaluated the impact of macroconsumers on leaf breakdown, macroinvertebrate abundance and biomass, and fungal biomass on the Great Pee Dee River floodplain using exclosures in 6 wetlands. Sweetgum (Liquidambar styraciflua) leaves were held in mesh bags and in leaf packs. After 301 days, breakdown rates (k) were low in all treatments (k < 0.003 day-1) and did not significantly differ. Fungal biomass also did not significantly differ between treatments nor did overall macroinvertebrate abundance or biomass. Collector-gatherer invertebrates were significantly more abundant in treatments open to macroconsumers in mesh bags (P<0.001). Shredders had significantly higher biomass in packs held in exclosures closed to macroconsumers (P=0.048). Lack of rain limited stream-floodplain connectivity so a second, shorter study was done in one flooded wetland. After 98 days, pre-conditioned leaves in mesh bags open to macroconsumers had significantly higher breakdown rates (k = 0.0078 day-1) than those closed to macroconsumers (k = 0.0058 day-1; P= 0.050). Fungal biomass did not significantly differ between treatments. Total macroinvertebrate abundance (but not biomass) was higher in mesh bags open to macroconsumers (P=0.014). Scrapers and predators were significantly more abundant in mesh bags opens to macroconsumers (P=0.001 and P=0.004, respectively) than those closed to macroconsumers. These results indicated macroconsumers had a larger impact on litter breakdown in wet floodplain wetlands than in dry ones.


Differences In Habitat At Two Spatial Scales Fail To Predict Differing Occurrences Of Three Species Of Wintering Ammodramus Sparrows In South Carolina Salt Marshes, Kimberly A. Trinkle Jan 2013

Differences In Habitat At Two Spatial Scales Fail To Predict Differing Occurrences Of Three Species Of Wintering Ammodramus Sparrows In South Carolina Salt Marshes, Kimberly A. Trinkle

Electronic Theses and Dissertations

Salt marshes have low levels of vertebrate diversity yet extremely high rates of endemism. Two of these endemic species are the Saltmarsh (Ammodramus caudacutus) and Seaside Sparrow (A. maritima); the closely related Nelson's sparrow (A. nelsoni) winters exclusively on salt marshes. A previous winter study found that individual sparrows of all three species were highly faithful to specific banding sites, and that the relative abundances of the three species differed by site. I hypothesized that the reason sparrow assemblages varied among sites was that the three species' winter habitat requirements were different. All three species winter in salt marshes, but …


The Real Alfred Russel Wallace: Essays On An Outside-The-Box Thinker, Charles H. Smith Jan 2013

The Real Alfred Russel Wallace: Essays On An Outside-The-Box Thinker, Charles H. Smith

Faculty/Staff Personal Papers

Alfred Russel Wallace (8 January 1823 – 7 November 1913), English polymath and social critic, ranks high on the list of the most interesting characters in the history of science. Nevertheless, and despite a life filled with achievement, he has often been marginalized in the halls of learning. The truth is, Wallace was something of an “outside–the–box” thinker, and his many forays into the murkier areas of science and social science cost him a lot of potential supporters. Still others, while recognizing his intellectual talents in general, have looked at the full span of his work and interests as a …


The Effects Of Thermal Stress And Algal Competition On The Early Life-History Stages Of Porites Astreoides And The Development Of Stress-Detecting Biomarkers For Use In Scleractinan Corals, Kevin C. Olsen Jan 2013

The Effects Of Thermal Stress And Algal Competition On The Early Life-History Stages Of Porites Astreoides And The Development Of Stress-Detecting Biomarkers For Use In Scleractinan Corals, Kevin C. Olsen

UNF Graduate Theses and Dissertations

Scleractinian coral populations are declining worldwide in response to numerous stressors operating on both global and regional scales. Rising sea surface temperatures associated with global climate change and the increasing frequency of coral-macroalgae competitive interactions are two of the gravest ecological drivers facing coral reef ecosystems. However, little is known about how these stressors interact to impact corals, their health, and potential modes of population recovery. These threats also highlight the need to develop reliable techniques that detect stress in multiple life-history stages of hermatypic corals prior to the degradation of coral reef habitats. To address these concerns we evaluated …


Aquatic Macroinvertebrate Response To Invasion And Subsequent Removal Of Typha × Glauca From Great Lakes Coastal Marshes, Kimberly Anne Greene Jan 2013

Aquatic Macroinvertebrate Response To Invasion And Subsequent Removal Of Typha × Glauca From Great Lakes Coastal Marshes, Kimberly Anne Greene

Master's Theses

Aquatic macroinvertebrates are important in wetland ecosystems; many fish and wildlife species depend upon them for food resources and they aid in nutrient cycling. Wetland macroinvertebrate communities are influenced by plant community composition; as such, this study examined two implications of invasive hybrid cattail, Typha × glauca (Typha), on aquatic macroinvertebrate communities in northern Great Lakes coastal wetlands: 1) how the presence of nearly monotypic stands of Typha alters wetland aquatic macroinvertebrate communities and 2) how manual removal of Typha, via mowing and manual tilling, impacts these invertebrate communities along with wetland plant communities. I found that …


Activity Patterns And Spatial Resource Selection Of The Eastern Garter Snake (Thamnophis Sirtalis Sirtalis), Matthew Gregory Most Jan 2013

Activity Patterns And Spatial Resource Selection Of The Eastern Garter Snake (Thamnophis Sirtalis Sirtalis), Matthew Gregory Most

Master's Theses

Snake species usually exhibit seasonal variations in activity patterns, home-range size and the use of respective habitat. Using mark-recapture protocols I marked 96 individual Thamnophis sirtalis sirtalis specimens in Lake Forest, IL to determine the independent variables that best explained habitat selection in a population of Eastern Garter Snakes (T. s. sirtalis). Specifically, I focused on the relationship between seasonal movement and home range size of male and female garter snakes. I analyzed the habitat preferences and spatial ecology of Eastern Garter Snakes during the 2011 sampling season and modeled the relationship between preferred or avoided habitat, in conjunction with …


A Reassessment Of The Conservation Status Of A Critically Endangered Neotropical Frog, Mannophryne Olmonae, Using Occupancy Modeling Techniques, Jessica Mcquigg Jan 2013

A Reassessment Of The Conservation Status Of A Critically Endangered Neotropical Frog, Mannophryne Olmonae, Using Occupancy Modeling Techniques, Jessica Mcquigg

Senior Independent Study Theses

Amphibian species worldwide are threatened with decline and extinction, making species monitoring an important scientific endeavor. The Bloody Bay Poison Frog, Mannophryne olmonae, a Tobago island endemic, was identified as critically endangered by the IUCN in 2004. Recent evidence suggests that a less severe conservation status may be appropriate for M. olmonae. This study employs acoustic calling surveys, land-use information, and multi-year (2011 and 2012) occupancy modeling techniques to propose an appropriate conservation status for this species. This study suggests that M. olmonae occupies a larger geographic range than was previously thought, and is not experiencing population declines. …


Horseshoe Crab Eggs: A Rare Resource For Predators In Long Island Sound, Mark Beekey, Jennifer Mattei, Barbara J. Pierce Jan 2013

Horseshoe Crab Eggs: A Rare Resource For Predators In Long Island Sound, Mark Beekey, Jennifer Mattei, Barbara J. Pierce

Biology Faculty Publications

In Delaware Bay, the spawning of several million horseshoe crabs (Limulus polyphemus) coincides with the arrival of migratory shorebirds that feed on their eggs. High horseshoe crab spawning densities and resulting high egg densities drive egg availability and predation rates. At high spawning densities, female horseshoe crabs perturb previously deposited clutches causing eggs to rise to the sediment surface (surface egg densities average 100,000 eggs m− 2). At the surface (0–5 cm), the eggs are quickly depleted by shorebirds and other predators. This interaction between egg density and egg predation has not been explicitly explored on …


Love Is In The Air: Olfaction-Based Mate-Odour Identification By Jumping Spiders From The Genus Cyrba, Ana M. Cerveira, Robert R. Jackson Jan 2013

Love Is In The Air: Olfaction-Based Mate-Odour Identification By Jumping Spiders From The Genus Cyrba, Ana M. Cerveira, Robert R. Jackson

All Peer-Reviewed Publications

Jumping spiders (Salticidae) are known for having good eyesight, but the extent to which they rely on olfaction is poorly understood. Here we demonstrate for the first time that olfactory pheromones are used by two species from the salticid genus Cyrba (C. algerina and C. ocellata). Using a Y-shape olfactometer, we investigated the ability of adult males and females of both species to discriminate between mate and non-mate odour. A hidden spider or a spider's draglines (no spider present) were used as odour sources. There was no evident response by females of either Cyrba species to any tested odour. Males …


Pine As Fast Food: Foraging Ecology Of An Endangered Cockatoo In A Forestry Landscape, William Stock, Hugh Finn, Jackson Parker, Ken Dods Jan 2013

Pine As Fast Food: Foraging Ecology Of An Endangered Cockatoo In A Forestry Landscape, William Stock, Hugh Finn, Jackson Parker, Ken Dods

Research outputs 2013

Pine plantations near Perth, Western Australia have provided an important food source for endangered Carnaby’s Cockatoos (Calyptorhynchus latirostris) since the 1940s. Plans to harvest these plantations without re-planting will remove this food source by 2031 or earlier. To assess the impact of pine removal, we studied the ecological association between Carnaby’s Cockatoos and pine using behavioural, nutritional, and phenological data. Pine plantations provided high densities of seed (158 025 seeds ha21) over a large area (c. 15 000 ha). Carnaby’s Cockatoos fed throughout these plantations and removed almost the entire annual crop of pine cones. Peak cockatoo abundance coincided with …


Quantifying Carbon Allocation To Mycorrhizal Fungi By Temperate Forest Tree Species Across A Nitrogen Availability Gradient, Shersingh Joseph Tumber-Davila Jan 2013

Quantifying Carbon Allocation To Mycorrhizal Fungi By Temperate Forest Tree Species Across A Nitrogen Availability Gradient, Shersingh Joseph Tumber-Davila

Honors Theses and Capstones

Terrestrial ecosystems make up the largest carbon pool with a major portion of that being forests. With carbon being a major concern due to global climate change, being able to make accurate models is increasingly important. Studies have shown that trees may allocate up to 50% of their photosynthetically fixed carbon underground; however these values haven’t been accurately quantified and underground carbon allocation has been historically overlooked. Mycorrhizal fungi may be a large portion of underground carbon allocation, as they have a symbiotic relationship with trees where they provide the plant with water and nutrients in return for sugars (carbon). …


Physiological And Behavioral Mechanisms Of Range Expansion In The House Sparrow (Passer Domesticus), Andrea Lyn Liebl Jan 2013

Physiological And Behavioral Mechanisms Of Range Expansion In The House Sparrow (Passer Domesticus), Andrea Lyn Liebl

USF Tampa Graduate Theses and Dissertations

Introduced species cause both considerable ecological and economic damage every year. However, not much is known about how certain species are able to establish and spread beyond the site of initial introduction, whereas others do not. Species undergoing range expansion following an introduction may prove to be a valuable resource to invasion biology, but may also be informative in light of species' responses to changing environments (i.e. global climate change). Here, I took advantage of an ongoing range expansion of an introduced vertebrate species. House sparrows (Passer domesticus) were introduced to Mombasa, Kenya in the 1950s and have subsequently expanded …


Understanding Amphibian Decline: The Role Of Pesticides And The Pathogenic Chytrid Fungus On Amphibians And Aquatic Communities, Taegan A. Mcmahon Jan 2013

Understanding Amphibian Decline: The Role Of Pesticides And The Pathogenic Chytrid Fungus On Amphibians And Aquatic Communities, Taegan A. Mcmahon

USF Tampa Graduate Theses and Dissertations

Amphibians are the most threatened taxon on the planet. Declines have been associated with over-exploitation, habitat loss, pollution, and pathogenic diseases, but of these factors, pollution and disease have been relatively under-studied. Here, I investigated: 1) the impacts of commonly used pesticides on aquatic communities, 2) the effect of these pesticides on amphibian susceptibility to the pathogenic chytrid fungus, Batrachochytrium dendrobatidis (Bd), and 3) whether there are non-amphibian hosts of Bd and 4) how to best quantify the survival of Bd through ontogeny of the host.

In my first research chapter, I quantified the effects of environmentally relevant concentrations of …


Agricultural And Domestic Waste Contamination In Chilibre Panama And Potential Low-Cost Best Managament Practices, Christopher Etienne Weekes Jan 2013

Agricultural And Domestic Waste Contamination In Chilibre Panama And Potential Low-Cost Best Managament Practices, Christopher Etienne Weekes

USF Tampa Graduate Theses and Dissertations

Abstract

Sanitation coverage in the Republic of Panama is 5 to 10 percent below the Millennium Development Goals targets set for the country. Population growth, urbanization, unplanned development and waste mismanagement have resulted in improvised trash sites and waste discharges into river systems that are important components of the biologically diverse natural environment of Panama. The study sought to investigate and estimate the burden of waste from domestic and agricultural sources in three regions of the Chilibre corrigimiento (district). It was hypothesized that the water quality and land cover data would reflect that the most populated region in the study …


Ecological Interactions Influencing Avicennia Germinans Propagule Dispersal And Seedling Establishment At Mangrove-Saltmarsh Boundaries, Jennifer Mcclain Peterson Jan 2013

Ecological Interactions Influencing Avicennia Germinans Propagule Dispersal And Seedling Establishment At Mangrove-Saltmarsh Boundaries, Jennifer Mcclain Peterson

USF Tampa Graduate Theses and Dissertations

Mangroves and saltmarshes are ecologically important coastal ecosystems; unfortunately, these low-lying coastal ecosystems are vulnerable to global climate change. As sea-levels rise, mangroves are expected to shift their distribution landward towards higher elevation sites that are occupied by other plants, including saltmarsh taxa. Therefore, mangrove recruits at the leading edge of expansion may interact with diverse assemblages of saltmarsh plants, and these interactions could influence the success of mangrove encroachment into higher tidal-elevation areas. The purpose of the research presented here was to investigate empirically the ecological interactions that may influence the recruitment of the black mangrove, Avicennia germinans, …


Gradients In Season, Latitude, And Sea Ice: Their Effect On Metabolism And Stable Isotopic Composition Of Antarctic Micronekton, Erica H. Ombres Jan 2013

Gradients In Season, Latitude, And Sea Ice: Their Effect On Metabolism And Stable Isotopic Composition Of Antarctic Micronekton, Erica H. Ombres

USF Tampa Graduate Theses and Dissertations

Respiration, metabolic enzyme assays, and body composition parameters were measured in the Antarctic krill Euphausia superba during the summer, fall and winter on the Western Antarctic Peninsula (WAP). E. superba of all sizes decrease their metabolism from the summer to the winter. These same parameters were also measured along the WAP during the austral fall 2010. E. superba's enzyme activity indicated that there was a latitudinal gradient to the decline in metabolism along the WAP with the more northerly sites having significantly higher metabolic enzyme activities than the sites to the south.

Carbon (δ13C) and nitrogen (δ15 …


An Investigation Of The Factors Leading To Invasion Success Of Non-Native Plants Using A System Of Native, Introduced Non-Invasive, And Invasive Eugenia Congeners In Florida, Kerry Bohl Jan 2013

An Investigation Of The Factors Leading To Invasion Success Of Non-Native Plants Using A System Of Native, Introduced Non-Invasive, And Invasive Eugenia Congeners In Florida, Kerry Bohl

USF Tampa Graduate Theses and Dissertations

The overwhelming majority of plant species introduced into a new range never become invasive. Consequently, identification of factors allowing the small fraction of successful invaders to naturalize, increase in abundance, and displace resident species continues to be a key area of research in invasion biology. Of the considerable number of hypotheses that have been proposed to resolve why some plant species become noxious pests, the enemy release hypothesis (ERH) is one of the most commonly cited. The ERH maintains that invasive plants succeed in a new range because they are no longer regulated by their coevolved natural enemies, and this …


Evaluating Habitat Vulnerability And Sustainability Of Urban Seagrass Resources To Sea Level Rise, Cynthia A. Meyer Jan 2013

Evaluating Habitat Vulnerability And Sustainability Of Urban Seagrass Resources To Sea Level Rise, Cynthia A. Meyer

USF Tampa Graduate Theses and Dissertations

The seagrass resource provides essential ecosystem functions for many marine species. This research evaluated the vulnerability and sustainability of the seagrass resource in an urbanized area to the effects of sea level rise. The assessment required analysis of information regarding the biogeography of the seagrass resource, and developing a method to model the spatial extent of the suitable habitat for seagrass, and applying the model to predict the implications of simulated sea level rise scenarios on the seagrass resource.

Examining the biogeography of the seagrass resource required the development of a seagrass monitoring and assessment field survey and a comprehensive …


Ecology Of The Late Neogene Extinctions: Perspectives From The Plio-Pleistocene Of Florida, Shubhabrata Paul Jan 2013

Ecology Of The Late Neogene Extinctions: Perspectives From The Plio-Pleistocene Of Florida, Shubhabrata Paul

USF Tampa Graduate Theses and Dissertations

The ecological impact of past extinction events is one of the central issues in paleobiology. In face of present environmental changes, a better understanding of past extinctions will enable us to identify the magnitude of biodiversity crises and their underlying processes. The Late Neogene was a time of extraordinary climatic reorganization, including Northern Hemisphere glaciation, the rise of the Central American Isthmus, and associated changes in environmental conditions. Therefore, the Late Neogene extinctions of marine molluscs of South Florida present an ideal platform to examine the interaction between environmental changes and biotic response. In the present study, three different aspects …


Associational Resistance And Competition In The Asphondylia - Borrichia - Iva System, Keith Stokes Jan 2013

Associational Resistance And Competition In The Asphondylia - Borrichia - Iva System, Keith Stokes

USF Tampa Graduate Theses and Dissertations

Indirect ecological effects such as associational resistance and resource competition have the potential to affect ecological interactions and influence the structure of ecological communities. Although resource competition is commonly studied, the effects of associational resistance are not as evident if studies are not designed to detect them. Additionally, the relative strengths of different ecological mechanisms ought to be measured in studies, rather than the strength of singular mechanisms. This permits proper attribution of causes and effects in community structure and detection of higher order interactions in a way that naïve reductionism will not.

In a series of experiments, I looked …


Phototactic Behaviour Of Subterranean Copionodontinae Pinna, 1992 Catfishes (Siluriformes, Trichomycteridae) From Chapada Diamantina, Central Bahia, Northeastern Brazil, Bianca Rantin, Maria Elina Bichuette Jan 2013

Phototactic Behaviour Of Subterranean Copionodontinae Pinna, 1992 Catfishes (Siluriformes, Trichomycteridae) From Chapada Diamantina, Central Bahia, Northeastern Brazil, Bianca Rantin, Maria Elina Bichuette

International Journal of Speleology

The phototactic behaviour of three Copionodontinae (Trichomycteridae) catfish species (two troglobites and one epigean) from Chapada Diamantina was studied in order to detect modifications related to isolation in the subterranean environment. Differences in response under different luminosities were detected and, unlike other cavefish, Copionodontinae cave species have shown to be more photophobic than the epigean syntopic to them. The troglobitic Glaphyropoma spinosum is the most photophobic, presenting this behaviour under all light intensities, and more homogeneous regarding morphological characters. It suggests that this population is probably isolated for a longer time in the subterranean environment compared to Copionodon sp. n., …


A History Of Place: Using Phytolith Analysis To Discern Holocene Vegetation Change On Sanak Island, Western Gulf Of Alaska, Cricket C. Wilbur Jan 2013

A History Of Place: Using Phytolith Analysis To Discern Holocene Vegetation Change On Sanak Island, Western Gulf Of Alaska, Cricket C. Wilbur

Antioch University Dissertations & Theses

This study investigated a terrestrial climate proxy, phytoliths, as a complimentary approach to documenting the dynamics of present and past vegetation on Sanak Island, the largest island in a small island group in the eastern Aleutian archipelago, and as a new basis by which to interpret Holocene environmental variability in Alaska. A phytolith reference collection was established from 59 selected plant species of maritime tundra belonging to 27 families. The grass species and a sedge species produced abundant phytolith forms whereas the majority of dicotyledons in this study were trace producers of phytoliths. A paleoenvironmental reconstruction from fossil phytoliths recovered …


Bacterial Colonization And Extinction On Marine Aggregates: Stochastic Model Of Species Presence And Abundance, Andrew M. Kramer, M. Maille Lyons, Fred C. Dobbs, John M. Drake Jan 2013

Bacterial Colonization And Extinction On Marine Aggregates: Stochastic Model Of Species Presence And Abundance, Andrew M. Kramer, M. Maille Lyons, Fred C. Dobbs, John M. Drake

OES Faculty Publications

Organic aggregates provide a favorable habitat for aquatic microbes, are efficiently filtered by shellfish, and may play a major role in the dynamics of aquatic pathogens. Quantifying this role requires understanding how pathogen abundance in the water and aggregate size interact to determine the presence and abundance of pathogen cells on individual aggregates. We build upon current understanding of the dynamics of bacteria and bacterial grazers on aggregates to develop a model for the dynamics of a bacterial pathogen species. The model accounts for the importance of stochasticity and the balance between colonization and extinction. Simulation results suggest that while …