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Arctic Alaskan Shrub Growth, Distribution, And Relationships To Landscape Processes And Climate During The 20th Century, Ken D. Tape

Biological Sciences

The primary change underway in the tundra of Arctic Alaska is the increase in air temperature and expansion of deciduous shrubs since 1980. I explored relationships between shrub expansion and relevant ecosystem properties such as climate, soil characteristics, erosion, and herbivory. Alnus viridis ssp. fruticosa (Siberian alder) shrubs located along streams, rock outcrops, or other features with active disturbance regimes showed a positive correlation between growth ring widths and March through July air temperature. Climate-growth relationships were much weaker for alder in adjacent tussock tundra. Additionally, tussock tundra sites had different vegetation composition, shallower thaw, lower mean annual ground temperature, …

Demographic Response Of American Ginseng (Panax Quinquefolius L.) To Climate Change, Sara Souther

Graduate Theses, Dissertations, and Problem Reports (ETD)

Ecological response to recent climate change has been documented for a multitude of species worldwide. Climate models predict further increases in temperature, as much as 8 times the degree of warming that has already occurred. Given observations of species response to contemporary climate change and the unprecedented degree of warming expected over the next century, climate change will no doubt determine future ecosystem composition and affect global species diversity. In order to prevent loss of biodiversity, it is necessary to understand and accurately project species' response to climate, and to identify species that are vulnerable to climate change driven extinctions. …

The Evolution And Reproductive Ecology Of Oenothera (Onagraceae), Kyra Krakos

All Theses and Dissertations (ETDs)

This dissertation describes the role of pollination in the floral diversification of Oenothera with an integration of both ecological and phylogenetic approaches. Oenothera: Onagraceae) is a model system for studying plant reproductive biology. It provides excellent examples of shifts in reproductive traits such as pollination and breeding system, features that have been important in angiosperm diversification. These systems are evolutionarily labile; they easily shift between different states. These different reproductive traits may shift in a concerted fashion; therefore, a more comprehensive approach to understanding the evolution of these plant systems simultaneously addresses shifts in pollination and breeding system. Using 54 …

Distribution, Growth, And Disturbance Of Catalina Island Rhodoliths, Paul Anthony Tompkins

Master's Theses

Rhodoliths are free-living coralline algae (Rhodophyta) that form large beds on the seafloor. Rhodolith beds are globally widespread and biologically diverse shallow marine habitats. Beds are ecologically sensitive, disturbed by humans, and in Europe are protected by law. While rhodolith beds have been found in California waters at Catalina Island, no literature exists regarding their distribution or ecological significance. This study sought to (1) map the distribution and characterize the rhodolith beds around Catalina, (2) determine the seasonal growth rates, and (3) investigate the effect of common sources of disturbance. A systematic search of shallow subtidal (0-40 meters) areas revealed …

Ecology Of The Rock Rattlesnake, Crotalus Lepidus, In The Northern Chihuahuan Desert, Vicente Mata Silva

Open Access Theses & Dissertations

The Rock Rattlesnake, Crotalus lepidus is a small species that is found from southern Arizona, southern New Mexico, and southern Texas, in the U.S., into northern Mexico. To date, little is known about the ecology of this species. Ecological information is becoming desperately needed for supporting the conservation and protection of species living in fragile environments such as the Chihuahuan Desert amid current local and global threats (e.g., habitat destruction and modification, urban development, and climate change). Although rattlesnakes spend a significant amount of time underground while overwintering, little is known about the physiology and behavior of these organisms during …

Development And Testing Of An Unmanned Aircraft System For Environmental Science, Jerald James Brady

Open Access Theses & Dissertations

For some environmental science applications, Unmanned Aircraft Systems (UASs) are increasingly recognized for their capacity to collect remotely sensed data in a safer, more efficient and effective manner than is permitted with manned aircraft and satellite remote sensing platforms. To date, however, technological, human, and other challenges have constrained adoption of UASs in the environmental sciences. This study developed and tested a new UAS for an archetypical environmental science research group (stakeholder) composed of non-UAS experts. Specifically, this thesis: 1) Assessed the research and operational needs of the stakeholder to determine the optimum UAS platform; 2) Developed an Unmanned Aerial …

Variation In The Trophic Position Of Spiny Dogfish (Squalus Acanthias) In The Northeastern Pacific Ocean: An Approach Using Carbon And Nitrogen Stable Isotopes, Alexander George Andrews

Fisheries

"Spiny dogfish (Squalus acanthias) are among the most abundant shark species in the Gulf of Alaska (GOA). An increase in relative biomass of spiny dogfish in 2003 and 2007 inspired interest in this species as a commercial resource. However, very little was known about the ecology of this species in the GOA. This study investigated the trophic role of spiny dogfish in the GOA, British Columbia (BC), and Washington using stable isotope analysis of carbon and nitrogen. Specifically, we examined the trophic position (TP) of spiny dogfish in relation to length, sex, and geographic region. Weathervane scallops (Patinopecten caurinus) were …

Roosting Ecology Of Bats In A Disturbed Landscape, Joshua B. Johnson

Graduate Theses, Dissertations, and Problem Reports (ETD)

In 2007 and 2008, I examined roost selection of forest-interior dwelling northern myotis (Myotis septentrionalis) maternity colonies in stands treated with prescribed fire (hereafter, fire) and in unburned (hereafter, control) stands on the Fernow Experimental Forest, West Virginia. Using radio telemetry, I tracked 36 female northern myotis to 69 roost trees; 25 in the fire treatment and 44 in the control treatment. Using logistic regression and an information-theoretic model selection approach, I determined that within the fire treatment, northern myotis maternity colonies were more likely to use cavity trees that were smaller in diameter, higher in crown class, and located …

Predicting Species Composition In An Eastern Hardwood Forest With The Use Of Digitally Derived Terrain Variables, Richard D. Flanigan

Graduate Theses, Dissertations, and Problem Reports (ETD)

This thesis addresses the need for improved classification of remotely sensed imagery in the complex hardwood forests of West Virginia. A geographic information system (GIS) was used in conjunction with forest plot data to develop a model to predict species composition in the eastern hardwood forest of West Virginia. The study area was located on the West Virginia University Research Forest (WVURF) in northern West Virginia. Terrain variables including aspect, curvature and slope change drastically at a local scale within the forest to greatly influence species composition. Light Detection and Ranging (LiDAR) data was collected for the entire WVURF, which …

Human-Wildlife Conflict Across Urbanization Gradients: Spatial, Social, And Ecological Factors, Amanda H. Gilleland

USF Tampa Graduate Theses and Dissertations

As suburban and exurban residential developments continue to multiply in urban areas, they encroach on wildlife habitats leading to increased human-wildlife interactions. The animals involved in direct conflict with homeowners are often relocated or exterminated by the homeowners. Often the homeowners contact state licensed wildlife trappers to eliminate the problem animal. In this study I examined how landscape, ecological, and social factors influence the incidence of human-wildlife conflict of thirty two residential areas in the Tampa, Florida metropolitan area. These residential areas, totaling over 300 km2, are part of the urban development gradient representing a range of urban land use …

Diversity And Distribution Of The Scarab Beetle Tribe Phanaeini In The Northern States Of The Brazilian Northeast (Coleoptera: Scarabaeidae: Scarabaeinae), Conrad P. D. T. Gillett, Michael P. T. Gillett, James E. D. T. Gillett, Fernando Z. Vaz-De-Mello

Insecta Mundi

The fauna of Phanaeini of the northeast of Brazil was investigated through fieldwork in the States of Ceará, Maranhão and Piauí, and through study of preserved material from other states. Seven species of Phanaeini are newly recorded from these three states. Of these, two species are also new records for the northeast region: Phanaeus melibaeus Blanchard and an unidentified Dendropaemon Perty species. A total of 13 new state records are given for eight of the 15 species of Phanaeini recorded from the northeast to date, including three new state genus records. A key is provided for identification of all species. …

Social Entrepreneurship In Context: Identity Emergence And Legitimation, Noushi Rahman Phd, Imran Chowdhury Phd

Wilson Center for Social Entrepreneurship

Community ecologists, who consider the interdependence among organizations of different forms (Hannan and Freeman, 1986), have argued that that legitimacy can flow between organizational forms if they are sufficiently related or proximate in cognitive space (Ruef, 2000). De alio legitimation, the process by which an established population can facilitate the institutionalization of an emergent population, greatly minimizes the time period needed for the new form to achieve a taken-for-granted status (Dobrev, 2001). While some studies have looked at how this process operates across populations of organizations within the commercial sector, no study has looked at how this legitimacy might travel …

The Effects Of Habitat Corridors And Edges On Sources Of Seed Mortality: Implications For Restoring A Threatened Legume, Melissa Simon

All Theses and Dissertations (ETDs)

No abstract provided.

Canopy Demographics At The Firestone Reserve, Costa Rica, Gizelle M. Pera

CMC Senior Theses

Though Costa Rica has suffered numerous bouts of deforestation to its valuable tropical rainforest area, especially in the 1970s, it has become a leader in its efforts to regenerate and restore its rainforest. However, studies and protocols for the assessment of forest regeneration are urgently required. Research has shown that the percentage of light penetrating the canopy floor, or light fraction, is a good indicator of rainforest maturity. In this study, digital rectilinear photography and a global positioning system receiver were used to survey the Firestone Reserve inCosta Rica in order to measure the light fraction differences between primary/riparian …

Isotopic Analysis Of Arctic Ground Squirrel Tissues And Potential Food Sources, Julee Shamhart

Master's Theses and Capstones

Given limited knowledge of the food sources of Arctic ground squirrels, an important arctic prey species, it is difficult to predict the implications of changes in food source availability that could result from climate change. I hypothesized that Arctic ground squirrels at two colonies, Atigun and Toolik, would have similar feeding habits and mushrooms would contribute to their diet The Arctic ground squirrels at Toolik had significantly higher del15N (3.7 per mill difference) and del13C values (1.3 per mill difference) than those at Atigun. Mixing models indicated that the signatures observed in the Atigun hair could result from a combination …

Trophic Implications Of Light Reductions For Amphibolis Griffithii Seagrass Fauna, Adam Gartner

Theses: Doctorates and Masters

The ongoing threat of seagrass loss from reduced light availability, coupled with our lack of knowledge of associated trophic responses has motivated this characterization of the flow-on effects of light reductions to Amphibolis griffithii seagrass fauna. Recently, field manipulations of varying light reductions, induced disturbances in a A. griffithii seagrass meadow that have been shown to effect potential food resources and the structural complexity of seagrass habitats for macroinvertebrates. This offered the opportunity to assess the flow-on effects to seagrass for fauna, a topic that has seldom been examined. This study investigated the effects of different light reduction intensity (high: …

Population Ecology And Reproductive Biology Of The Diamondback Watersnake, Nerodia Rhombifer (Serpentes: Colubridae), In Southernmost Texas, Ruben D. Zamora

Theses and Dissertations - UTB/UTPA

Nerodia rhombifer is a polytypic, semi-aquatic snake with a broad geographical distribution ranging from the American Midwest southward to Chiapas, Mexico. Although relatively abundant throughout much of its range, few ecological studies of the species have been conducted. This study provides basic population ecology information in a subtropical habitat. Population data were obtained in a mark-recapture study at Santa Ana National Wildlife Refuge, Hidalgo County, Texas, from August 1995 to December 1998. Specimens taken elsewhere in Hidalgo County provided information on the reproductive biology. This study provides the first absolute density estimates from anywhere within the species’ range. Quantitative information …

Mining And Residential Development Interact To Produce Highly Impaired Stream Conditions In An Intensively Mined Appalachian Watershed, Eric Richard Merriam

Graduate Theses, Dissertations, and Problem Reports (ETD)

Large scale surface mining in southern West Virginia causes significant alteration of headwater stream networks. It is unclear, however, the extent to which mining interacts with other stressors to determine physical, chemical, and biological conditions in aquatic systems downstream. Through a watershed scale assessment of Pigeon Creek, the specific objectives of this study were to: (1) quantify the direct and interactive effects of mining and residential development on in-stream conditions; and (2) identify landscape thresholds above which biological impairment occurs. Our results indicate high levels of impairment to habitat, water quality, and benthic invertebrate communities within this watershed. Statistical analyses …

Habitat Selection And Predation Risk In Larval Lampreys, Dustin M. Smith

Graduate Theses, Dissertations, and Problem Reports (ETD)

This thesis examines habitat preference and the influence of habitat on predation of larvae (ammocoetes) of the least brook lamprey (Lampetra aepyptera). The thesis comprises three chapters: (1) an introduction and literature review on the general life history of lampreys and on studies related to ammocoetes and their habitat, (2) an experimental study of habitat preference in ammocoetes of the least brook lamprey, and (3) an experimental study of the relationship between habitat availability and predation risk in ammocoetes. For the first study, we quantified substrate selection in small (< 50 mm) and large (100-150 mm) ammocoetes of the least brook lamprey. In aquaria, ammocoetes were given a choice to burrow into six equally-available substrate types: small gravel (2.36-4.75 mm), coarse sand (0.5-1.4 mm), fine sand (0.125-0.5 mm), organic debris (approximately 70% decomposing leaves and stems, 15% silt, and 15% sand), an even mixture of silt, clay, and fine sand, and silt/clay (< 0.063 mm). Fine sand was selected with a significantly higher probability than any other substrate. In the second study, we experimentally examined the influence of habitat availability on predation risk of ammocoetes. Ammocoetes were placed in aquaria containing a predator species (yellow bullhead, Ameiurus natalis) and one of 3 substrates: fine sand (0.125-0.5 mm), coarse sand (0.5-1.4 mm), or silt/clay (<0.063 mm). Use of the three substrate types was based on a previous experiment where fine sand was determined to be the preferred benthic habitat of least brook lamprey. Based on 10 trials with each habitat type, survival of ammocoetes was highest in aquaria with fine sand (mean = 80%), and lower in those with coarse sand (mean = 58%) and silt/clay (mean = 4%). The results of both studies conducted indicate that populations of least brook lamprey ammocoetes may be limited by the availability of fine sand habitat. The first study indicated that least brook lamprey ammocoetes are habitat specialists, preferring substrates composed primarily of fine sand. The second study showed that the availability of fine sand habitat may influence the predation risk of ammocoetes, as ammocoete survival from predation was highest in fine sand, and lower in other substrates.

Foraging Ecology Of Male Cerulean Warblers And Other Neotropical Migrants, Gregory A. George

Graduate Theses, Dissertations, and Problem Reports (ETD)

Understanding foraging ecology provides insight into species resource requirements and overall conservation needs. We examined foraging behavior and tree species selection of male Cerulean Warblers (Dendroica cerulea ) (n = 673) in response to varying degrees of habitat disturbance from silvicultural treatments at four study sites in West Virginia, Kentucky and Ohio, during the 2006 and 2007 breeding seasons. Cerulean Warblers foraged primarily in the forest canopy, along branch tips by gleaning insects off leaf surfaces, often adjacent to canopy gaps, both pre- and post-harvest. Tree species availability, based on importance values (IV) calculated from density, frequency and basal areas, …

Differential Response Of Amp Activated Protein Kinase (Ampk) And Hsp70 To Temperature Stress In The Gastropod, Nucella Lapillus, Emily Zimmermann

All Theses And Dissertations

Populations of the gastropod Nucella lapillus are polymorphic for shell color, with light-colored shells predominating on warmer, wave-protected shores and dark-colored shells limited primarily to cooler, wave-exposed shores. During thermal stress, darker shells attain higher body temperatures than lighter shells. These results suggest that heat stress may determine field distribution patterns. However, there is currently little evidence of physiological consequences of thermal stress in these organisms. Following the guiding hypothesis that heat stress leads to cellular energy depletion, we explored whether the central energy regulator AMP-activated Protein Kinase (AMPK) is activated by heat stress. We compared this response in both …

Beyond Stewardship: Toward An Agapeic Environmental Ethic, Christopher J. Vena

Dissertations (1934 -)

This dissertation is a work in theological anthropology and environmental philosophy. It seeks to provide a conceptual framework for a Christian environmental ethic rooted in love.

The heart of the crisis of ecological degradation is found in human attitudes and behaviors. In the late 1960's it was suggested that Christianity was a key source of the problem because it promoted the idea of human "dominion" over creation. This spurred a variety of responses designed to show that Christian faith was compatible with environmental care. A key theme emerging from this debate was the image of humans as Stewards of God's …

Fish Distributions And Nutrient Cycling In Streams: Can Fish Create Biogeochemical Hotspots, Peter B. Mcintyre, Alexander S. Flecker, Michael J. Vanni, James M. Hood, Brad W. Taylor, Steven A. Thomas

Dartmouth Scholarship

Rates of biogeochemical processes often vary widely in space and time, and characterizing this variation is critical for understanding ecosystem functioning. In streams, spatial hotspots of nutrient transformations are generally attributed to physical and microbial processes. Here we examine the potential for heterogeneous distributions of fish to generate hotspots of nutrient recycling. We measured nitrogen (N) and phosphorus (P) excretion rates of 47 species of fish in an N-limited Neotropical stream, and we combined these data with population densities in each of 49 stream channel units to estimate unit- and reach-scale nutrient recycling. Species varied widely in rates of N …

Predictive Modeling Of Freshwater Mussels (Unionidae) In The Appalachians, Alison R. Mynsberge

Graduate Theses, Dissertations, and Problem Reports (ETD)

Freshwater mussels are in decline, particularly in the Appalachian region of North America. This region contains the world's greatest diversity of freshwater mussels, but many species are now threatened or endangered. Little is known of the basic ecology and distributions of species of freshwater mussels relative to other freshwater organisms. The goal of this study was to use predictive modeling to predict distributions of freshwater mussels in the Appalachians and identify correlated factors using a watershed framework. Models were developed in the upper Mid-Atlantic and Ohio drainage regions using subwatersheds and separately in the Tennessee region using catchments. Models developed …

Juvenile Bristol Bay Sockeye Salmon Ecology, Edward V. Farley

Fisheries

Predicting annual returns of Bristol Bay sockeye salmon (Oncorhynchus nerka) has been difficult due to large, unexplained variations in return strength. Ocean conditions, particularly during the first few months after salmon leave freshwater, are believed to have a strong influence on their early marine growth and survival. Limited historical and present research suggests that sea temperature can affect juvenile Bristol Bay distribution. During years with cool spring sea temperatures, juvenile sockeye salmon are distributed nearshore along the Alaska Peninsula, whereas they are found further offshore during years with warm spring sea temperatures. Juvenile sockeye salmon are larger, in better condition, …

Survival Strategies Of Eelgrass In Reduced Light, Caroline A. Ochieng

Doctoral Dissertations

Light reduction due to anthropogenic impacts is the most widespread cause of worldwide decline of eelgrass, an ecologically important marine angiosperm whose role in supporting overall coastal ecosystem productivity has been widely recognized. Understanding eelgrass plant and meadow responses to light reduction has therefore received significant research interest over the last 30 years, while managers have sought tools to identify critical thresholds for light availability and predict impacts of human-induced disturbances in order to prevent further eelgrass loss. In the present thesis, a review of some of the literature on light reduction and its effects on eelgrass (i) summarized the …

Effects Of Agricultural Conservation Practices On Fish And Wildlife, Stuart R. Gagnon, Joseph R. Makuch, Cassandra Y. Harper

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

This bibliography, in two volumes, is part of a multi-volume set developed by the Water Quality Information Center at the National Agricultural Library in support of the U.S. Department of Agriculture’s Conservation Effects Assessment Project (CEAP). The bibliography is a guide to recent scientific literature covering effects of agricultural conservation practices on fish and wildlife. The citations listed here provide information on how conservation programs and practices designed to improve fish and wildlife habitat, as well as those intended for other purposes, e.g., water quality improvement, affect various aquatic and terrestrial fauna.

A New Perspective: Atlantic Herring (Clupea Harengus) As A Case Study For Time Series Analysis And Historical Data, Emily Klein

Master's Theses and Capstones

This thesis endeavors to develop methods for the historical analysis of a specific species and location to begin understanding fishery patterns and change over time. The main goal was to develop statistical methods to address historical data and provide long-term information on fishery trends and potential relationships between the fishery and outside influences. The Atlantic herring (Clupea harengus) fishery was investigated for underlying patterns and the possible impact of outside variables and events from 1870 to 2007.

In the Gulf of Maine, Atlantic herring (Clupea harengus) provide critical forage for many economically valuable species, while supporting a major New England …

Early Performance Of Constructed Oyster Reefs In Great Bay, New Hampshire, Mark K. Capone

Master's Theses and Capstones

Several oyster reefs were constructed in Great Bay, New Hampshire using remotely-set oysters. A single large reef treatment and a cluster of several small reefs treatment were utilized to test hypotheses relevant to oyster restoration design, and to monitor early restoration reef performance. There was no significant difference in oyster size, density, and recruitment between two experimental reef structures, with both reef types having high survival and fast growth rates for the 2-year study. Both experimental reef structures had significantly higher recruitment rates than natural reefs in 2006, a year of relatively high recruitment (p < 0.05), and elevated yet not significantly higher recruitment rates in 2005, a weak recruitment year (p = 0.078). In situ fluorometry data showed that a restored reef can significantly impact chlorophyll-a levels in overlying water within two years of reef construction. Individual oyster clearance rates ranged from 1.87 L/hr--2.41L/hr.

Ecological Genomics: Understanding Gene And Genome Function In The Natural Environment, M. C. Ungerer, L. C. Johnson, M. A. Herman

School of Biological Sciences: Faculty Publications

The field of ecological genomics seeks to understand the genetic mechanisms underlying responses of organisms to their natural environments. This is being achieved through the application of functional genomic approaches to identify and characterize genes with ecological and evolutionary relevance. By its very nature, ecological genomics is an interdisciplinary field. In this review, we consider the significance of this new area of study from both an ecological and genomic perspective using examples from the recent literature. We submit that by considering more fully an ecological context, researchers may gain additional insights into the underlying genetic basis of ecologically relevant phenotypic …