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Reconstructing Energy Flow Through Modern And Historical Marine Communities: Insights From Amino Acid Isotope Analysis, Emma A. Elliott Smith Dec 2019

Reconstructing Energy Flow Through Modern And Historical Marine Communities: Insights From Amino Acid Isotope Analysis, Emma A. Elliott Smith

Biology ETDs

The fundamental currency of life is energy. Organisms need energy to grow, to survive and to reproduce. Understanding the acquisition of energy by consumers is thus a foundational aspect of biological research. This is especially important in the modern era, as impacts of ongoing anthropogenic effects will be mediated or amplified through food webs. Here, I explore how isotopic analysis of individual amino acids – a technique new to ecological studies – can be used to trace energy flow through animal communities in modern and ancient time periods. In particular, I focus on kelp forest food webs, which are nearshore …


Characterizing Dryland Ecosystems Using Remote Sensing And Dynamic Global Vegetation Modeling, Abdolhamid Dashtiahangar Dec 2019

Characterizing Dryland Ecosystems Using Remote Sensing And Dynamic Global Vegetation Modeling, Abdolhamid Dashtiahangar

Boise State University Theses and Dissertations

Drylands include all terrestrial regions where the production of crops, forage, wood and other ecosystem services are limited by water. These ecosystems cover approximately 40% of the earth terrestrial surface and accommodate more than 2 billion people (Millennium Ecosystem Assessment, 2005). Moreover, the interannual variability of the global carbon budget is strongly regulated by vegetation dynamics in drylands. Understanding the dynamics of such ecosystems is significant for assessing the potential for and impacts of natural or anthropogenic disturbances and mitigation planning, and a necessary step toward enhancing the economic and social well-being of dryland communities in a sustainable manner (Global …


Enabling High Quality Oxygen Measurements During Robotic Based Studies Of Ocean Ecological And Biogeochemical Processes, Brianna A. Alanis Dec 2019

Enabling High Quality Oxygen Measurements During Robotic Based Studies Of Ocean Ecological And Biogeochemical Processes, Brianna A. Alanis

Theses and Dissertations

Dissolved oxygen is an essential parameter necessary for understanding marine ecological and biogeochemical processes. New robotic vehicles and autonomous platforms are being applied to an even wider range of ecological and biogeochemical studies. Thus, arises the opportunity for matching the best possible oxygen sensing techniques and methods to these new platforms. In so doing, we can enable both more targeted and higher resolution oxygen measurements than previously possible and potentially use oxygen measurements for a wider range of applications, including in situ incubation experiments and primary productivity measurements. This thesis tested three different oxygen sensors in a trade study for …


Effects Of Water Table Depth And Edaphic Characteristics On Plant Diversity In A Southern Mississippi Pitcher Plant Bog, Patrick Kirby Dec 2019

Effects Of Water Table Depth And Edaphic Characteristics On Plant Diversity In A Southern Mississippi Pitcher Plant Bog, Patrick Kirby

Master's Theses

This study examined the effects that water table depth and soil characteristics have on plant species richness and species composition within pitcher plant bogs across seasons. Eight piezometers were installed at random distances to monitor long-term water table depth and pressure fluctuations along a ~710-meter line transect traversing upland and bog habitats. Vegetation sampling quadrats (n=128) were set up near each piezometer. Cover data and water table depths were collected in spring and late summer. Soil samples collected from each treatment group were used to obtain soil texture and nutrient data. The summer collection period yielded a total gdiversity of …


The Peculiar Nature Of Florida’S Sandhill Wetlands, Ponds & Lakes— Their Ecohydrology, Relationship With The Regional Aquifer & Importance Within The Landscape., Renae Starr Nowicki Nov 2019

The Peculiar Nature Of Florida’S Sandhill Wetlands, Ponds & Lakes— Their Ecohydrology, Relationship With The Regional Aquifer & Importance Within The Landscape., Renae Starr Nowicki

USF Tampa Graduate Theses and Dissertations

This dissertation explores the ecohydrology of Florida’s peculiar and poorly studied sandhill wetland and water features, particularly those located in west-central Florida. The primary research goals include: compilation and summarization of the available ecohydrologic information for features across Florida; comparison of water level and water geochemistry data between sandhill wetlands and waters and the regional aquifer to provide evidence of regional hydrologic control; and use of geophysical applications to examine the hydraulic connections between sandhill wetlands and waters and the regional aquifer.

From this research, a natural history of sandhill wetland and water ecohydrology is presented, highlighting: the differences between …


Spatial And Seasonal Differences In The Top Predators Of Easter Island: Essential Data For Implementing The New Rapa Nui Multiple‐Uses Marine Protected Area, Naiti A. Morales, Erin E. Easton, Alan M. Friedlander, Euan S. Harvey, Rodrigo Garcia, Carlos F. Gaymer Oct 2019

Spatial And Seasonal Differences In The Top Predators Of Easter Island: Essential Data For Implementing The New Rapa Nui Multiple‐Uses Marine Protected Area, Naiti A. Morales, Erin E. Easton, Alan M. Friedlander, Euan S. Harvey, Rodrigo Garcia, Carlos F. Gaymer

School of Earth, Environmental, & Marine Sciences Faculty Publications

  1. Reef fishes are an important component of marine biodiversity, and changes in the composition of the assemblage structure may indicate ecological, climatic, or anthropogenic disturbances. To examine spatial differences in the reef fish assemblage structure around Easter Island, eight sites were sampled during autumn and summer 2016–2017 with baited remote underwater video systems.
  2. To determine seasonal changes, quarterly (seasonal) sampling was conducted at five of those eight sites. Fifteen pelagic species of fishes were recorded during this study, some of which have not previously been recorded in scuba surveys, including the Galapagos shark (Carcharhinus galapagensis, Snodgrass & Heller, …


United States Midwest Soil And Weather Conditions Influence Anaerobic Potentially Mineralizable Nitrogen, Jason D. Clark, Kristen S. Veum, Fabian G. Fernandez, James J. Camberato, Paul R. Carter, Richard B. Ferguson, David W. Franzen, Daniel E. Kaiser, Newell R. Kitchen, Carrie A.M. Laboski, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan Sep 2019

United States Midwest Soil And Weather Conditions Influence Anaerobic Potentially Mineralizable Nitrogen, Jason D. Clark, Kristen S. Veum, Fabian G. Fernandez, James J. Camberato, Paul R. Carter, Richard B. Ferguson, David W. Franzen, Daniel E. Kaiser, Newell R. Kitchen, Carrie A.M. Laboski, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan

Agronomy, Horticulture and Plant Science Faculty Publications

Nitrogen provided to crops through mineralization is an important factor in N management guidelines. Understanding of the interactive effects of soil and weather conditions on N mineralization needs to be improved. Relationships between anaerobic potentially mineralizable N (PMNan) and soil and weather conditions were evaluated under the contrasting climates of eight US Midwestern states. Soil was sampled (0–30 cm) for PMNan analysis before pre-plant N application (PP0N) and at the V5 development stage from the pre-plant 0 (V50N) and 180 kg N ha−1 (V5180N) rates and incubated for 7, 14, …


Traffic Noise And Sexual Selection: Studies Of Anthropogenic Impact On Bird Songs And Undergraduate Student Reasoning Of Evolutionary Mechanisms, Sarah Spier Aug 2019

Traffic Noise And Sexual Selection: Studies Of Anthropogenic Impact On Bird Songs And Undergraduate Student Reasoning Of Evolutionary Mechanisms, Sarah Spier

School of Natural Resources: Dissertations, Theses, and Student Research

Humans have transformed much of the natural landscape and are continuing to do so at an accelerated rate, compromising natural areas that serve as important habitat for many species. Roads impact much of the environment as they fragment habitat and introduce traffic noise into the acoustic environment, deferentially affecting wildlife in roadside habitat. I explored how traffic noise affects the detection of birds based on whether their vocalizations were masked by traffic noise. Masked species detection was not affected by an increase in traffic noise amplitude, while there was a negative effect of traffic noise amplitude on unmasked species detection, …


Assessing Minimal-Input Restoration Strategies For Desert Soil And Vegetation Restoration, Audrey Jean Rader May 2019

Assessing Minimal-Input Restoration Strategies For Desert Soil And Vegetation Restoration, Audrey Jean Rader

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Mojave and Sonoran Deserts have been negatively impacted by anthropogenic disturbances. Considering that these ecosystems may recover on millennial timescales, research has shown that restoration techniques can be fairly successful in initiating long-term recovery processes in these sensitive environments. However, uncertainty remains as to which techniques are effective in different circumstances, such as in different climates or across different soil properties, and which techniques may best avoid unintended consequences, such as facilitating non-native plants. To reduce fugitive dust as a human health hazard, increase soil stability, and enhance wildlife habitat, further work is necessary to develop restoration techniques for …


Ocean Robots Uncover Microbial Secrets, Susan Evans, Jim Birch, John A. Breier, Michael V. Jakuba, Mak A. Saito, Julie Robidart Feb 2019

Ocean Robots Uncover Microbial Secrets, Susan Evans, Jim Birch, John A. Breier, Michael V. Jakuba, Mak A. Saito, Julie Robidart

School of Earth, Environmental, & Marine Sciences Faculty Publications

Life on Earth began in the sea, and the oceans continue to support life on our planet. Of particular importance is the ability of marine microbes to exist in a complex web of relationships where substances are continually transformed and exchanged.


Monitoring Spatial And Temporal Variabilities Of Gross Primary Production Using Maiac Modis Data, Marcos Fernandez-Martinez, Rong Yu, John Gamon, Gabriel Hmimina, Iolanda Filella, Manuela Balzarolo, Benjamin Stocker, Josep Penuelas Jan 2019

Monitoring Spatial And Temporal Variabilities Of Gross Primary Production Using Maiac Modis Data, Marcos Fernandez-Martinez, Rong Yu, John Gamon, Gabriel Hmimina, Iolanda Filella, Manuela Balzarolo, Benjamin Stocker, Josep Penuelas

Center for Advanced Land Management Information Technologies: Publications

Remotely sensed vegetation indices (RSVIs) can be used to efficiently estimate terrestrial primary productivity across space and time. Terrestrial productivity, however, has many facets (e.g., spatial and temporal variability, including seasonality, interannual variability, and trends), and different vegetation indices may not be equally good at predicting them. Their accuracy in monitoring productivity has been mostly tested in single-ecosystem studies, but their performance in different ecosystems distributed over large areas still needs to be fully explored. To fill this gap, we identified the facets of terrestrial gross primary production (GPP) that could be monitored using RSVIs. We compared the temporal and …


Floristic Quality Assessments Of Remnant Natural Areas In The Greater Grand Rapids, Michigan Region: Evaluating Botanical Change Since The 1890s, Alan W. Stockdale, Garrett Crow, David P. Warners Jan 2019

Floristic Quality Assessments Of Remnant Natural Areas In The Greater Grand Rapids, Michigan Region: Evaluating Botanical Change Since The 1890s, Alan W. Stockdale, Garrett Crow, David P. Warners

Faculty and Professional Research

In 1901, Emma J. Cole, a beloved high school teacher and distinguished botanist, published Grand Rapids Flora. Cole’s floristic inventory remains the most comprehensive botanical study of the greater Grand Rapids, Michigan region, even though this area has experienced significant land- scape alterations since her publication. To address this knowledge gap, in 2014 we embarked on a multiple-year project aimed to discover and reassess the sites Cole described, as well as to catalog other natural remnant locations within the Grand Rapids area. This paper reports botanical invento- ries that were completed at eight sites within Kent County during 2015 and …


Environmental Forensic Characterization Of Former Rail Yard Soils Located Adjacent To The Statue Of Liberty In The New York/New Jersey Harbor, Diane Hagmann, Michael A. Kruge, Matthew Chi-Hymn Cheung, Maria Mastalerz, José Luis Gallego, Jay Prakash Singh, Jennifer Krumins, Xiaona N. Li, Nina M. Goodey Jan 2019

Environmental Forensic Characterization Of Former Rail Yard Soils Located Adjacent To The Statue Of Liberty In The New York/New Jersey Harbor, Diane Hagmann, Michael A. Kruge, Matthew Chi-Hymn Cheung, Maria Mastalerz, José Luis Gallego, Jay Prakash Singh, Jennifer Krumins, Xiaona N. Li, Nina M. Goodey

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Identifying inorganic and organic soil contaminants in urban brownfields can give insights into the adverse effects of industrial activities on soil function, ecological health, and environmental quality. Liberty State Park in Jersey City (N.J., USA) once supported a major rail yard that had dock facilities for both cargo and passenger service; a portion remains closed to the public, and a forest developed and spread in this area. The objectives of this study were to: 1) characterize the organic and inorganic compounds in Liberty State Park soils and compare the findings to an uncontaminated reference site (Hutcheson Memorial Forest); and 2) …


Compound-Specific Isotope Analysis Of Amino Acids In Biological Tissues: Applications In Forensic Entomology, Food Authentication And Soft-Biometrics In Humans, Mayara Patricia Viana De Matos Jan 2019

Compound-Specific Isotope Analysis Of Amino Acids In Biological Tissues: Applications In Forensic Entomology, Food Authentication And Soft-Biometrics In Humans, Mayara Patricia Viana De Matos

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this work we demonstrate the power of compound-specific isotope analysis (CSIA) to analyze proteinaceous biological materials in three distinct forensic applications, including: 1) linking necrophagous blow flies in different life stages to their primary carrion diet; 2) identifying the harvesting area of oysters for food authentication purposes; and 3) the ability to predict biometric traits about humans from their hair.

In the first application, we measured the amino-acid-level fractionation that occurs at each major life stage of Calliphora vicina (Robineau-Desvoidy) (Diptera: Calliphoridae) blow flies. Adult blow flies oviposited on raw pork muscle, beef muscle, or chicken liver. Larvae, pupae …


Impacts Of Plant-Microbe Interactions On Seedling Performance In A Riparian Forest Invaded By Lonicera Maackii, Taylor E. K. Strehl Jan 2019

Impacts Of Plant-Microbe Interactions On Seedling Performance In A Riparian Forest Invaded By Lonicera Maackii, Taylor E. K. Strehl

Masters Theses

Soil microbes have profound impacts on plant growth and survival and can either promote or inhibit plant dominance. Exotic plants are often strongly invasive because they have escaped their natural enemies, potentially including antagonistic soil microbes. I examined how the invasive shrub Lonicera maackii and a common native tree, Acer negundo, responded to soil microbial communities to determine the role of soil microbes in regulating invasion success. This was done by growing both species with microbes from invaded (L. maackii) and uninvaded (A. negundo) soils collected from three locations within a riparian forest. Seedlings were …


Middle To Late Holocene (7200-2900 Cal. Bp) Archaeological Site Formation Processes At Crumps Sink And The Origins Of Anthropogenic Environments In Central Kentucky, Usa, Justin Nels Carlson Jan 2019

Middle To Late Holocene (7200-2900 Cal. Bp) Archaeological Site Formation Processes At Crumps Sink And The Origins Of Anthropogenic Environments In Central Kentucky, Usa, Justin Nels Carlson

Theses and Dissertations--Anthropology

Though some researchers have argued that the Big Barrens grasslands of Kentucky were the product of anthropogenic land clearing practices by Native Americans, heretofore, this hypothesis had not been tested archaeologically. More work was needed to refine chronologies of fire activity in the region, determine the extent to which humans played a role in the process, and integrate these findings with the paleoenvironmental and archaeological record. With these goals in mind, I conducted archaeological and geoarchaeological investigations at Crumps Sink in the Sinkhole Plain of Kentucky. The archaeological record and site formation history of Crumps Sink were compared with environmental …


Historic Log Buildings As Archives Of Past Forest Ecology, Kristen K. De Graauw Jan 2019

Historic Log Buildings As Archives Of Past Forest Ecology, Kristen K. De Graauw

Graduate Theses, Dissertations, and Problem Reports (ETD)

This dissertation is composed of three separate but related manuscripts with the common theme of using historic log buildings from the central Appalachian Mountain region of eastern North America as ecological archives. In Chapter 1, I explore the biases, limitations, and ecological applications of tree-ring data from historic log buildings. European immigrants selected trees from a forested stand based on species, log sizes, and construction locations. Despite this selection bias, ecological information can be gleaned from historic log buildings, which offer a complementary record of past forest ecology and represent a site type that is not often associated with old-growth …


Relationships Between Landscape Constraints And A Crayfish Assemblage With Consideration Of Competitor Presence, Joshua B. Mouser, Robert Mollenhauer, Shannon K. Brewer Jul 2018

Relationships Between Landscape Constraints And A Crayfish Assemblage With Consideration Of Competitor Presence, Joshua B. Mouser, Robert Mollenhauer, Shannon K. Brewer

United States Geological Survey: Staff Publications

Aim: Crayfish are globally diverse and one of the most important taxa in North American streams. Despite their importance, many species are of conservation concern and efforts to improve conditions are limited. Here, we address two major impediments to improving conditions: (a) our lack of knowledge of the interplay among natural landscape and human-induced changes; and (b) a very limited understanding of how species interactions affect overall crayfish distributions.

Location: Ozark Highlands ecoregion, USA.

Methods: We used both existing data and field-collected data to examine the relationships between 12 Faxonius species and physicochemical variables at multiple spatial scales. Data were …


Micropaleontological Record Of A Preserved, Late Pleistocene Bald Cypress Forest On The Northern Gulf Of Mexico Inner Shelf, Jonathan Thien Truong May 2018

Micropaleontological Record Of A Preserved, Late Pleistocene Bald Cypress Forest On The Northern Gulf Of Mexico Inner Shelf, Jonathan Thien Truong

LSU Master's Theses

A cluster of previously buried Taxodium distichum stumps are exposed and preserved in growth position at the bottom of a trough on the inner Gulf of Mexico (GOM) continental shelf in 18 m water depth and 13 km offshore Orange Beach, AL. Radiocarbon ages from wood and optically stimulated luminescence (OSL) dating of sediments suggest a Marine Isotope Stage (MIS) 3 age, or older. This study builds on the previous work of Gonzalez (2018) and Obeclz (2017). Five biofacies were identified in vibracore collected in 2015 and 2016: 1) the Holocene Mississippi-Alabama-Florida (MAFLA) sand sheet, 2) a Holocene interbedded sand …


Nebraska Wetland Condition Assessment: Intensification Of The National Wetland Condition Assessment Throughout Nebraska, Cody Dreier May 2018

Nebraska Wetland Condition Assessment: Intensification Of The National Wetland Condition Assessment Throughout Nebraska, Cody Dreier

School of Natural Resources: Dissertations, Theses, and Student Research

Even though wetlands provide a habitat for many plants and animals and numerous services for humans, they were not always treated as areas of value. Less than half of the United States’ pre-colonial wetlands have survived to the present day. Seeing a need to understand the remaining wetlands more fully, the Environmental Protection Agency developed the National Wetland Condition Assessment to monitor target wetlands throughout the country every five years.

This study is an intensification of the National Wetland Condition Assessment for Nebraska wetlands that allowed us to sample more areas of the state and gather additional information. During the …


Extraction Of Metazoan Meiofauna From Muddy Deep-Sea Samples: Operator And Taxon Effects On Efficiency, Melissa Rohal, David Thistle, Erin E. Easton May 2018

Extraction Of Metazoan Meiofauna From Muddy Deep-Sea Samples: Operator And Taxon Effects On Efficiency, Melissa Rohal, David Thistle, Erin E. Easton

School of Earth, Environmental, & Marine Sciences Faculty Publications

Deep-sea metazoan meiofaunal specimens are usually extracted from muddy samples by centrifugation in a fluid in which meiofauna tend to float and sediment particles tend to sink. Although the procedure is in common use, its efficiency has seldom been examined. The study reported here showed that well-trained operators extracted metazoan meiofauna with efficiencies that were different enough to be a concern in quantitative studies. Therefore, samples should be assigned to operators in a stratified-random manner. In the course of these studies, both operators also extracted individuals of the common nematode family Desmoscolecidae significantly less efficiently than other nematode families, a …


Remote Sensing And Spatial Metrics For Quantifying Seagrass Landscape Changes: A Study On The 2011 Indian River Lagoon Florida Seagrass Die-Off Event, René Dieter Baumstark Mar 2018

Remote Sensing And Spatial Metrics For Quantifying Seagrass Landscape Changes: A Study On The 2011 Indian River Lagoon Florida Seagrass Die-Off Event, René Dieter Baumstark

USF Tampa Graduate Theses and Dissertations

Florida’s seagrasses are ecologically important marine environments which have suffered major degradation caused by increasing anthropogenic pressures. A 2011 seagrass die-off event caused by an algal bloom in the Florida Indian River Lagoon (IRL) was particularly severe with a majority of seagrass lost in areas such as the Banana River. An understanding of how this coastal marine environment changed is an important step toward better managing resources for conservation. Modern tools and methods provide new opportunities to study these changes at the landscape scale, a scale that informs on the larger more comprehensive state of a system. Classified satellite imagery …


The Flathead Catfish Invasion Of The Great Lakes, Pam L. Fuller, Gary E. Whelan Jan 2018

The Flathead Catfish Invasion Of The Great Lakes, Pam L. Fuller, Gary E. Whelan

United States Geological Survey: Staff Publications

A detailed review of historical literature andmuseumdata revealed that flathead catfish were not historically native in the Great Lakes Basin, with the possible exception of a relict population in Lake Erie. The species has invaded Lake Erie, Lake St. Clair, Lake Huron, nearly all drainages in Michigan, and the Fox/Wolf and Milwaukee drainages in Wisconsin. They have not been collected from Lake Superior yet, and the temperature suitability of that lake is questionable. Flathead catfish have been stocked sparingly in the Great Lakes and is not the mechanism responsible for their spread. A stocking in 1968 in Ohio may be …


Accounting For Spatial Autocorrelation In Modeling The Distribution Of Water Quality Variables, Lorrayne Miralha Jan 2018

Accounting For Spatial Autocorrelation In Modeling The Distribution Of Water Quality Variables, Lorrayne Miralha

Theses and Dissertations--Geography

Several studies in hydrology have reported differences in outcomes between models in which spatial autocorrelation (SAC) is accounted for and those in which SAC is not. However, the capacity to predict the magnitude of such differences is still ambiguous. In this thesis, I hypothesized that SAC, inherently possessed by a response variable, influences spatial modeling outcomes. I selected ten watersheds in the USA and analyzed them to determine whether water quality variables with higher Moran’s I values undergo greater increases in the coefficient of determination (R²) and greater decreases in residual SAC (rSAC) after spatial modeling. I compared non-spatial ordinary …


Preferential Production And Transport Of Grass-Derived Pyrogenic Carbon In Ne-Australian Savanna Ecosystems, Gustavo Saiz, Iain Goodrick, Christopher Wurster, Paul N. Nelson, Jonathan G. Wynn, Michael Bird Jan 2018

Preferential Production And Transport Of Grass-Derived Pyrogenic Carbon In Ne-Australian Savanna Ecosystems, Gustavo Saiz, Iain Goodrick, Christopher Wurster, Paul N. Nelson, Jonathan G. Wynn, Michael Bird

School of Geosciences Faculty and Staff Publications

Understanding the main factors driving fire regimes in grasslands and savannas is critical to better manage their biodiversity and functions. Moreover, improving our knowledge on pyrogenic carbon (PyC) dynamics, including formation, transport and deposition, is fundamental to better understand a significant slow-cycling component of the global carbon cycle, particularly as these ecosystems account for a substantial proportion of the area globally burnt. However, a thorough assessment of past fire regimes in grass-dominated ecosystems is problematic due to challenges in interpreting the charcoal record of sediments. It is therefore critical to adopt appropriate sampling and analytical methods to allow the acquisition …


Recent Ecological Change In Ancient Lakes, Stephanie E. Hampton, Suzanne Mcgowan, Ted Ozersky, Salvatore G. P. Virdis, Tuong Thuy Vu, Trisha L. Spanbauer, Benjamin M. Kraemer, George Swann, Anson W. Mackay, Stephen M. Powers, Michael F. Meyer, Stephanie G. Labou, Catherine M. O'Reilly, Morgan Dicarlo, Aaron W. E. Galloway, Sherilyn C. Fritz Jan 2018

Recent Ecological Change In Ancient Lakes, Stephanie E. Hampton, Suzanne Mcgowan, Ted Ozersky, Salvatore G. P. Virdis, Tuong Thuy Vu, Trisha L. Spanbauer, Benjamin M. Kraemer, George Swann, Anson W. Mackay, Stephen M. Powers, Michael F. Meyer, Stephanie G. Labou, Catherine M. O'Reilly, Morgan Dicarlo, Aaron W. E. Galloway, Sherilyn C. Fritz

Department of Earth and Atmospheric Sciences: Faculty Publications

Ancient lakes are among the best archivists of past environmental change, having experienced more than one full glacial cycle, a wide range of climatic conditions, tectonic events, and long association with human settlements. These lakes not only record long histories of environmental variation and human activity in their sediments, but also harbor very high levels of biodiversity and endemism. Yet, ancient lakes are faced with a familiar suite of anthropogenic threats, which may degrade the unusual properties that make them especially valuable to science and society. In all ancient lakes for which data exist, significant warming of surface waters has …


Effects Of Water Level Increase On Phytoplankton Assemblages In A Drinking Water Reservoir, Yangdong Pan, Shijun Guo, Yuying Li, Wei Yin, Pengcheng Qi, Jainwei Shi, Lanqun Hu, Bing Li, Shengge Bi, Jingya Zhu Jan 2018

Effects Of Water Level Increase On Phytoplankton Assemblages In A Drinking Water Reservoir, Yangdong Pan, Shijun Guo, Yuying Li, Wei Yin, Pengcheng Qi, Jainwei Shi, Lanqun Hu, Bing Li, Shengge Bi, Jingya Zhu

Environmental Science and Management Faculty Publications and Presentations

Excessive water level fluctuation may affect physico-chemical characteristics, and consequently ecosystem function, in lakes and reservoirs. In this study, we assessed the changes of phytoplankton assemblages in response to water level increase in Danjiangkou Reservoir, one of the largest drinking water reservoirs in Asia. The water level increased from a low of 137 m to 161 m in 2014 as a part of the South–North Water Diversion Project. Phytoplankton assemblages were sampled four times per year before, during and after the water level increase, at 10 sites. Environmental variables such as total nitrogen as well as phytoplankton biomass decreased after …


Functional Predictions Of Microbial Communities In Soil As Affected By Long‐Term Tillage Practices, Janani Hariharan, Aditi Sengupta, Parwinder Grewal, Warren A. Dick Dec 2017

Functional Predictions Of Microbial Communities In Soil As Affected By Long‐Term Tillage Practices, Janani Hariharan, Aditi Sengupta, Parwinder Grewal, Warren A. Dick

School of Earth, Environmental, & Marine Sciences Faculty Publications

Core Ideas

  • Microbial function is important but difficult to assess in soil.
  • An omics‐driven tool, PICRUSt, was used to characterize functions of soil microbial communities.
  • No‐tillage compared with plow tillage was functionally enriched for most nutrient cycles.
  • Many other functions integral to soil health can be explored by the PICRUSt omics approach.

Soil microbial communities affect the soil's biological, chemical, and physical properties, but there is still a knowledge gap regarding the long‐term impact of tillage practices on soil microbial dynamics. Additionally, the accurate identification of belowground microbial functions is a topic of active interest. In this study, microbial community …


Shrubs Facilitate Recruitment Of Caragana Stenophylla Pojark: Microhabitat Amelioration And Protection Against Herbivory, Li-Na Xie, Hong-Yu Guo, Zhe Liu, Christopher A. Gabler, Wei-Zhong Chen, Song Gu, Cheng-Cang Ma Oct 2017

Shrubs Facilitate Recruitment Of Caragana Stenophylla Pojark: Microhabitat Amelioration And Protection Against Herbivory, Li-Na Xie, Hong-Yu Guo, Zhe Liu, Christopher A. Gabler, Wei-Zhong Chen, Song Gu, Cheng-Cang Ma

School of Earth, Environmental, & Marine Sciences Faculty Publications

Key message

Mature Caragana stenophylla shrubs facilitated intraspecific sapling establishment by two mechanisms: microhabitat amelioration and protection against herbivory. Facilitation was mediated by climate, grazing, and sapling age.

Context

Pre-existing shrubs could facilitate sapling establishment of woody plants; however, how these facilitation vary across abiotic and biotic stress gradients and the underlying mechanisms remain unclear.

Aims

The aim of this study is understanding the facilitation of shrub on sapling establishment and how the two underlying mechanisms, microhabitat amelioration and protection against herbivory, vary across climatic aridity gradients, grazing gradients, and sapling age.

Methods

We conducted field sowing experiments to examine …


Using Stable Isotope Geochemistry To Determine Changing Paleohydrology And Diagenetic Alteration In The Late Cretaceous Kaiparowits Formation, Ut Usa, Daigo Yamamura Aug 2017

Using Stable Isotope Geochemistry To Determine Changing Paleohydrology And Diagenetic Alteration In The Late Cretaceous Kaiparowits Formation, Ut Usa, Daigo Yamamura

Graduate Theses and Dissertations

The Western Interior Basin of the North America preserves one of the best sedimentary and paleontological records of the Cretaceous in the world. The Upper Cretaceous Kaiparowits Formation is a rapidly deposited fluvial sequence and preserves one of the most complete terrestrial fossil record of the North America. Such a unique deposit provides an opportunity to investigate the interaction between the physical environment and ecology. In an effort to decipher such interaction, stable isotope composition of cements in sedimentary rocks, concretions and vertebrate fossils were analyzed.

Despite the difference in facies and sedimentary architecture, the isotope composition does not change …