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

Digital Commons Network

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

Articles 1 - 24 of 24

Full-Text Articles in Entire DC Network

Hydrological Characterization Of A Riparian Vegetation Zone Using High Resolution Multi-Spectral Airborne Imagery, Osama Zaki Akasheh Dec 2008

Hydrological Characterization Of A Riparian Vegetation Zone Using High Resolution Multi-Spectral Airborne Imagery, Osama Zaki Akasheh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Middle Rio Grande River (MRGR) is the main source of fresh water for the state of New Mexico. Located in an arid area with scarce local water resources, this has led to extensive diversions of river water to supply the high demand from municipalities and irrigated agricultural activities. The extensive water diversions over the last few decades have affected the composition of the native riparian vegetation by decreasing the area of cottonwood and coyote willow and increasing the spread of invasive species such as Tamarisk and Russian Olives, harmful to the river system, due to their high transpiration rates, …


Soil Moisture Responses In Traditional And Drought Adapted Landscapes In The Intermountain West, James Gregory Dec 2008

Soil Moisture Responses In Traditional And Drought Adapted Landscapes In The Intermountain West, James Gregory

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water conservation in the Intermountain West will be an important issue in the future as population and demand for limited water resources increases. In Utah, outdoor water use accounts for up to 60% of total per capita water use with 67% of that outdoor water being used to irrigate non native plant species to maintain a uniform green appearance. The objective of this study was to measure intra landscape changes in soil water potential during a 21.5 day dry down from DOY 215 to 236.5 in the summer of 2005 and 2006. Four, 2 x 2 replicated traditional and drought …


Decadal-Scale Changes On Coral Reefs In Quintana Roo, Mexico, Thaddeus Allen Nicholls Dec 2008

Decadal-Scale Changes On Coral Reefs In Quintana Roo, Mexico, Thaddeus Allen Nicholls

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In 1988 data on coral reef community composition were collected from two areas, Akumal and Chemuyil, Quintana Roo, Mexico, ranging from 5-35m depth. These areas were revisited in 2005 and data were collected by the same methods and at the same depths as in 1988. Data from 1988 and 2005 were compared to determine if the coral reefs had undergone significant changes, and what specific changes had occurred. Chi-square analysis determined that community composition data collected in 1988 are significantly different from data collected in 2005 at all sites and depths within the categories of corals, gorgonians, sponges, and macroalgae. …


Development And Evaluation Of A Minimally Invasive Sampling Technique To Estimate The Age Of Living Birds, Crissa K. Cooey Dec 2008

Development And Evaluation Of A Minimally Invasive Sampling Technique To Estimate The Age Of Living Birds, Crissa K. Cooey

Graduate Theses, Dissertations, and Problem Reports

Using pest species in initial studies of pentosidine (Ps) aging research for birds may be the catalyst to discovering more effective population control strategies for pest, invasive, and hard to manage birds. Pentosidine is an irreversible, stable, fluorescent, collagen cross-link, created through the Maillard reaction, which has been found to accumulate throughout the lifetime of an organism in various body parts such as skin, lens crystalline, and dura matter. Pentosidine assays are more accurate at determining the age of adult birds in comparison to plumage coloration, eye and mouth color, feather wear, and molt sequences due to the discovery that …


Ecology Of A Central Appalachian White-Tailed Deer Herd At Low Density, Shawn M. Crimmins Dec 2008

Ecology Of A Central Appalachian White-Tailed Deer Herd At Low Density, Shawn M. Crimmins

Graduate Theses, Dissertations, and Problem Reports

White-tailed deer (Odocoileus virginianus) are the most abundant big game species in North America and serve as the dominant herbivore in the majority of the Appalachian region. Despite the abundance of research conducted on this species, relatively little is known of the ecology of white-tailed deer occurring at low densities. Our study population experienced a 75% decline in population density and a three-fold increase in habitat disturbance via timber harvests between 2002 and 2005. From May 2006 to April 2008 I examined the home-range, survival, and herbivory patterns of a central Appalachian white-tailed deer herd that has recently experienced both …


Eco_Urbanism Restitching Clearwater's Urban Fabric Through Transit And Nature, Daniel P. Uebler Nov 2008

Eco_Urbanism Restitching Clearwater's Urban Fabric Through Transit And Nature, Daniel P. Uebler

USF Tampa Graduate Theses and Dissertations

Downtown Clearwater has grown to be disconnected from its surroundings due to an adjacent buffer area and the lack of a transit system to bring people into the city. The downtown core is also separated from its neighboring residential areas by an area of vacant land that holds in it the potential to become a gateway into the city. On a macro scale the city has grown to be separated from the Tampa Bay area due to the lack of a mass transit system.

The goal of this project is to create a new "new urbanism" in which transit and …


Predictive Modeling Of Freshwater Mussels (Unionidae) In The Appalachians, Alison R. Mynsberge Aug 2008

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

Graduate Theses, Dissertations, and Problem Reports

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 …


The Reproductive Ecology Of Graptemys Geographica In The Central Canal, Kati Keppen Rush May 2008

The Reproductive Ecology Of Graptemys Geographica In The Central Canal, Kati Keppen Rush

Undergraduate Honors Thesis Collection

Life for all organisms involves carefully managing a limited amount of resources. In many cases these resources affect how organisms Jive on a daily basis. In addition to competition from other species, organisms face competition within their own species, populations, and niches. Those individuals that manage their resources effectively will increase their chances of survival, reproduction, and the continuation of their genes in the gene pool. Studies that focus on life history characteristics of organisms aim to understand the mechanisms used by organisms to increase the chances that their genes will remain in thegenepoolpasttheirown Iifetime.Thegoal ofthesemechanisms istoensuresurvival and maximize reproduction. …


Ecology, Problem Framing And Local Land Use Controls: A Case Study Of Socio-Ecological Governance In Franklin County, Idaho, Alissa Salmore May 2008

Ecology, Problem Framing And Local Land Use Controls: A Case Study Of Socio-Ecological Governance In Franklin County, Idaho, Alissa Salmore

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Due to the continuity of energy and material flows, the persistence of an ecological network necessarily includes a linking of ecological units from local and immediate to regional and broad-ranging scales. Humans are an integral part of ecosystems acting as resource consumers and agents of change, and all systems can be considered combined 'socio-ecological' systems. Where environmental and social systems lack coordination, mismatches between the temporal, spatial or functional scales at which these systems operate lead to resource use inefficiencies and the loss of ecosystem components and functioning. This case study of Franklin County, Idaho documents a recent land use …


Spatial Modeling Of Propagule Pressure In Ailanthus Altissima, Matthew A. Kaproth May 2008

Spatial Modeling Of Propagule Pressure In Ailanthus Altissima, Matthew A. Kaproth

Graduate Theses, Dissertations, and Problem Reports

Ailanthus altissima (tree of heaven) is a non-native invasive tree spreading within central Appalachia. This dioecious, deciduous, and allelopathic species copiously produces samaras, capable of traveling at least 200 m through primary wind-dispersal. Removal of A. altissima individuals prior to timbering and other forest disturbances may help prevent spread into forest interiors. To aid in species management, this study investigated the use of remote sensing to identify the location and abundance of samaras in mixed mesophytic forests through supervised classifications. From empirical measurements, the estimated number of seeds per classified unit area was determined and the relationship between quantified propagule …


Evaluation Of The Impacts Of Highway Construction On Sediment And Benthic Macroinvertebrates In Appalachian Streams, Lara B. Hedrick May 2008

Evaluation Of The Impacts Of Highway Construction On Sediment And Benthic Macroinvertebrates In Appalachian Streams, Lara B. Hedrick

Graduate Theses, Dissertations, and Problem Reports

Corridor H is a four-lane highway under construction in north eastern West Virginia. I used a variety of methods to assess the impacts of highway construction in the Lost River watershed, Hardy County, West Virginia. I designed a two part sediment sampler to be used to monitor sediment in paired sites upstream and downstream of highway construction. The two-part design, a base that remains embedded in the substrate, and a removeable trap, allowed for long-term placement of samplers without continual disturbance of the streambed. I used a laboratory flume to compare my sediment sampler design with other devices used to …


Evolution Of Dioecy In Echinocereus Coccineus: Relative Influence Of Pollinators, Resources And Elevation Over Multiple Spatial Scales, Summer Ann Scobell Apr 2008

Evolution Of Dioecy In Echinocereus Coccineus: Relative Influence Of Pollinators, Resources And Elevation Over Multiple Spatial Scales, Summer Ann Scobell

Open Access Dissertations

"Why have separate sexes?" is a fundamental question in biology and has been investigated intensively since Darwin first proposed two hypotheses: Separate sexes evolve 1) to avoid detrimental effects of self-fertilization or 2) to improve allocation of scarce resources to each sex's reproductive function. In animal-pollinated plants dioecy is hypothesized to be favored when small, generalized pollinators predominate because they increase self-fertilization rates of plants. I concurrently tested Darwin's hypotheses using Echinocereus coccineus (Cactaceae). I found, as predicted, when specialized pollinators (hummingbirds) were excluded from plants and only generalized pollinators (bees) visited, selfing rates of plants increased 238%. High selfing …


Ecophysiology Of The Gray Snapper (Lutjanus Griseus): Salinity Effects On Abundance, Physiology And Behavior, Xaymara M. Serrano Jan 2008

Ecophysiology Of The Gray Snapper (Lutjanus Griseus): Salinity Effects On Abundance, Physiology And Behavior, Xaymara M. Serrano

Open Access Theses

Mangroves and seagrass beds serve as essential fish habitat for many economically- and ecologically-valuable species. Depending on their location, these shallow-water habitats are often characterized by substantial fluctuation in salinity levels, which can represent a source of osmoregulatory stress for associated organisms. In South Florida, one of the most important fish species that utilizes these habitats is the gray snapper (Lutjanus griseus). Although this species constitutes a significant portion of the region?s total recreational fishery harvest, the effects of salinity on its distribution, physiology and behavior remain poorly understood. The main goal of this thesis was then to investigate the …


A New Perspective: Atlantic Herring (Clupea Harengus) As A Case Study For Time Series Analysis And Historical Data, Emily Klein Jan 2008

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 …


Survival Strategies Of Eelgrass In Reduced Light, Caroline A. Ochieng Jan 2008

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 …


The Development Of A Modular Integrated Recirculating Aquaculture System Using Porphyra (Nori) For The Bioremediation Of Marine Finfish Effluent, Jennifer Pauline Day Jan 2008

The Development Of A Modular Integrated Recirculating Aquaculture System Using Porphyra (Nori) For The Bioremediation Of Marine Finfish Effluent, Jennifer Pauline Day

Doctoral Dissertations

It is crucial for the development of the fish aquaculture industry to be managed in a way that provides a reliable, long term source of products without negatively impacting the environment. The simplest form of integrated multi-tropic aquaculture (IMTA) uses a fed component (e.g. finfish) and an extractive component (e.g. seaweed) to remove the inorganic metabolites from finfish aquaculture effluent. In IMTA systems metabolic wastes become nutrients for the other cultured organisms and are incorporated into potentially valuable biomass. A demonstration-scale Modular Integrated Recirculating Aquaculture Systems (MIRAS) was constructed in a greenhouse adjacent to Great Bay Aquaculture, LLC (GBA), Newington, …


Effects Of Vegetated Buffers On Salt Marsh Plant Composition And Groundwater Nitrogen Uptake, Joanne Singfield Glode Jan 2008

Effects Of Vegetated Buffers On Salt Marsh Plant Composition And Groundwater Nitrogen Uptake, Joanne Singfield Glode

Master's Theses and Capstones

Vegetated shoreline buffers are a best management practice to reduce anthropogenic nitrogen influences on estuarine ecology. This study examined the effects of buffers on (1) groundwater chemistry; (2) the salt marsh border plant community (fertilized and control); and (3) Agropyron pungens response to fertilization. All buffer widths (5 to 15 meters) were somewhat effective at removing groundwater nutrients, with greater concentrations of TDN, NO3--N, NH4 +-N, and DOC found in groundwater wells upslope of the buffer. Although on-site manure storage resulted in 30-fold greater groundwater nitrate concentrations (mean 23 mg/L) at the widest buffer, no differences were found in nitrate …


Spectral Effects Of A Calcium Amendment On Red Spruce Foliage At Laboratory And Stand Scale, Will Robinson Kessler Jan 2008

Spectral Effects Of A Calcium Amendment On Red Spruce Foliage At Laboratory And Stand Scale, Will Robinson Kessler

Master's Theses and Capstones

Three sets of measurements were made to determine the effects of an October 1999 whole-watershed Ca-application on the chemical and spectral properties of red spruce (Picea rubens Sarg.) foliage at the Hubbard Brook Experimental Forest. Results of our measurements showed significant differences between the Ca-treated watershed (WS1) and a nearby reference watershed (WS6). Foliar chemistry data collected in 2007 showed that concentrations of Ca, Sr, and oxalate remain higher in WS1, and the increase in oxalate is strongly linked to the level of total Ca, possibly by a Ca-oxalate crystal precipitation response. High-resolution laboratory spectral data measured from 400-2500 nm …


Early Performance Of Constructed Oyster Reefs In Great Bay, New Hampshire, Mark K. Capone Jan 2008

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.


Protistan Predation And Tce Biodegradation In A Fractured Rock Aquifer, Joseph J. Cunningham Iii. Jan 2008

Protistan Predation And Tce Biodegradation In A Fractured Rock Aquifer, Joseph J. Cunningham Iii.

Master's Theses and Capstones

Despite extensive research on the resources required to initiate dechlorination of trichloroethene (TCE), slow rates and stalling continue to be observed in situ. The majority of research on biodegradation of TCE has focused resource availability, while predation is poorly understood. Predation has the potential to significantly alter bacterial abundance, and can play an important role in selecting what species are present, and determine if the community is capable of mineralizing TCE. The impact of protistan predation on TCE biodegradation rates, and occurrence and length of stalls was measured in this experiment. When protists were inhibited, TCE was mineralized. Protistan predation …


Ecology, Distribution, Quantification, And Impact Of Introduced, Asian Porphyra Yezoensis F Yezoensis Ueda And Porphyra Yezoensis F Narawaensis A Miura In The Northwestern Atlantic, Jeremy C. Nettleton Jan 2008

Ecology, Distribution, Quantification, And Impact Of Introduced, Asian Porphyra Yezoensis F Yezoensis Ueda And Porphyra Yezoensis F Narawaensis A Miura In The Northwestern Atlantic, Jeremy C. Nettleton

Master's Theses and Capstones

Invasive species pose a threat to the balance of intertidal ecosystems. Recently, two forms of the non-native species, Porphyra yezoensis Ueda, were found at multiple sites between New York and Downcast Maine. A 2007 New England survey confirmed the presence of P. yezoensis f. yezoensis at nine sites, including two beyond its reported distribution. Porphyra yezoensis f narawaensis A. Miura was found at four sites in Long Island Sound. To assess the ecological impact of f. yezoensis and f. narawaensis on Northwest Atlantic macroalgal communities, monthly density and biomass data were gathered in 2008 from seven southern New England sites …


Eelgrass In The Great Bay Estuary, New Hampshire And Maine: Monitoring Eelgrass Decline And Educating Local Students, Nora Thompson Beem Jan 2008

Eelgrass In The Great Bay Estuary, New Hampshire And Maine: Monitoring Eelgrass Decline And Educating Local Students, Nora Thompson Beem

Master's Theses and Capstones

Eelgrass monitoring efforts in the Great Bay Estuary (GBE), New Hampshire and Maine, by the New Hampshire Port Authority Mitigation Project (Chp. II) and Nutrient Pollution Indicator (NPI) testing (Chp. III) both confirmed a recent trend of eelgrass decline within the GBE. The decline has been most noticeable in the mid-estuary, where four major tributaries drain into the GBE. Eelgrass beds in proximity to Portsmouth's wastewater treatment facility have also experienced decline, highlighting the effects of such point sources on the eelgrass population.

In an effort to introduce eelgrass, its recent decline and its role in the ecology of the …


Use Of Genetic Tagging To Estimate Abundance And Detect Spatial Patterns Of Black Bears In New Hampshire, Stephanie Coster Jan 2008

Use Of Genetic Tagging To Estimate Abundance And Detect Spatial Patterns Of Black Bears In New Hampshire, Stephanie Coster

Master's Theses and Capstones

Abundance estimates for black bears (Ursus americanus) are an important tool for effective management. Recent advancements in DNA technology have enabled genetic tagging mark-recapture population estimates using DNA from hair samples. I conducted a population estimate using genetic tagging in 2 study sites presumed to have different bear densities in northern New Hampshire (Pittsburg and Milan). To test repeatability, I conducted the genetic tagging estimates in 2 consecutive years. I also compared these estimates to those derived from traditional methods used by the New Hampshire Fish and Game Department (NHFG) using hunter harvest and mortality data. I found that the …


Drought Traits Of Eucalyptus Gomphocephala In Yalgorup National Park, Paul L. Drake Jan 2008

Drought Traits Of Eucalyptus Gomphocephala In Yalgorup National Park, Paul L. Drake

Theses: Doctorates and Masters

Isohydric and anisohydric regulation of plant water status has been observed over several decades of field, glasshouse and laboratory studies, yet the functional significance and mechanism of both remain obscure. W e studied the seasonal trends in plant water status and hydraulic properties in a natural stand of Eucalyptus gomphocephala through cycles of varying environmental moisture (rainfall, groundwater depth, evaporative demand ) in order to test for isohydry and to provide physiological information for the mechanistic interpretation of seasonal trends in plant water status. Over a 16-month period of monitoring, spanning two summers, midday leaf water potential correlated with pre-dawn …