Life Sciences Commons^™

Leaf Optical And Indirect Lai Measurements In Wheat And Alfalfa At Maciv: Agmet Progress Report 89-4, E. A. Walter-Shea, B. L. Blad

School of Natural Resources: Documents and Reviews

No abstract provided.

The Impacts Of Permafrost Thaw Slumps On Arctic Stream Ecology, Maria Dolan

Theses and Dissertations (Comprehensive)

Climate change is intensifying permafrost thaw across terrain of the circumpolar Arctic. Increased temperatures and rainfall at northern latitudes have resulted in the expansion of thermokarst features such as retrogressive thaw slumps, which make previously frozen debris available for transport into nearby river systems. In the Peel Plateau, Northwest Territories, the mobilization of these materials exposes rivers to a large quantity of sediment and solutes that may act as a chronic, press disturbance, potentially altering stream food webs. Here, I examine if: 1) thaw slumps have driven changes to the physical and biological properties of slump impacted streams since an …

Determination Of A New Spring-Flying Species Of The Pterourus Glaucus Complex (Papilionidae) In Southern New England, Harry Pavulaan

The Taxonomic Report of the International Lepidoptera Survey

The Pterourus glaucus complex in three southern New England states is analyzed for cryptic speciation. What was historically considered to be one species, P. glaucus (Linnaeus, 1758), was recently split to separate P. canadensis (Rothschild & Jordan, 1906) at species rank (Hagen et al., 1991). Additionally, P. appalachiensis Pavulaan & Wright, 2002, was described as an Appalachian Mountain endemic. The western member of the complex, P. rutulus (Lucas, 1852), has frequently been considered a subspecies of P. glaucus (Scott, 1986; Tyler, Brown & Wilson, 1994), as was P. alexiares (Höpffer, 1866) (Tyler, Brown & …

Working In Pairs Increases Consistency Of Georgia Adopt-A-Stream's Habitat Assessment, Christopher H. Kodani, Robert Bourne, Cody Jones, Michael Kahle, Cecilia Nachtmann

Georgia Journal of Science

Habitat assessment is a skill that is important to stream ecologists of all levels, including volunteers of water quality monitoring programs such as Georgia Adopt-A-Stream (AAS). Some aspects of habitat assessment can be subjective because observers must use their best judgement in assessing some variables, therefore, it is worthwhile to examine the variation in volunteer stream monitor observations, the effect of training, and the reliability of habitat metrics calculated from the data collected. To gain some insight, we asked volunteers attending a workshop at AAS’s 2022 Confluence Conference to complete a Habitat Assessment Worksheet both before and after a short …

The Moon Jelly, Adam Krogmann

PANDION: The Osprey Journal of Research and Ideas

Artist Statement

The Moon Jelly is a piece I created as a part of the Scientific Illustration course I participated in during the summer semester of 2023. This piece was inspired by the livestreams of the Monterey Bay Aquarium that film these moon jellies (Aurelia aurita) in their tank. The Moon Jelly is an ink drawing created as part of a collection focused on Monterey Bay Aquarium animals. Through this artwork I hoped to draw attention to smaller marine animals that may otherwise be overlooked even though they provide a vital role in the ecosystem. Moon jellyfish are important marine …

Psychological And Social Well-Being Of Bony Fishes In Zoos And Aquariums, Ronald G. Oldfield, Patrick Bonano

Animal Sentience

Research on the behaviour of animals in zoos has been conducted for decades, and observations have provided information that has improved the psychological and social well-being of animals. However, research on fishes in zoos and aquariums seems to be lacking. Here, we assess the current state of research on fishes in zoos and aquariums by surveying the peer-reviewed literature. Our assessment differs from previous surveys in that we examine the taxonomic classes Chondrichthyes (sharks and rays) and Osteichthyes (bony fishes) separately. Our survey finds that bony fishes have been drastically underrepresented in zoo journals, more drastically than chondrichthyans, revealing an …

Exploring Biosignatures And Biogeochemical Processes In Lanzarote Lava Tubes: Implications For Martian Analog Research, Vera Palma, Ana Z. Miller, Francesco Sauro, Bogdan P. Onac, José M. De La Rosa, Sara Gutiérrez-Patricio, Beatriz Cubero, José A. Gonzalez-Perez, Jesus Martínez-Frías, A Teresa Caldeira

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.

Emerging Contaminants In Extreme Environments: Microplastics Monitoring In Karst Springs Of Montenegro, Marko Nikolic, Djuradj Milosevic, Ana Manovic, Vladimir Pesic, Melita Mustafic, Dragana Asceric, Milica Nikolic, Dimitrija Savic-Zdravkovic

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.

High Mountain Ecosystems And Snow Cover In A Changing Climate: For Better Or For Worse, Philippe Choler

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.

Exploring Pristine Microbial Ecosystems From The Uninhabited Volcanic Selvagens Islands, Pedro N. Jiménez-Morillo, Sara Gutiérrez-Patricio, Vera Palma, Ana Teresa Caldeira, Nicasio Tomás Jiménez-Morillo, Ana Z. Miller

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.

Of Geese And Grass: Investigating Impacts Of Brant Grazing On Eeelgrass, Dakota L. Osborne

Master's Theses

Grazing pressure is important in structuring plant communities, particularly in aquatic environments. Eelgrass (Zostera marina), a keystone species in estuaries across North America, is experiencing widespread population declines. As a keystone species, eelgrass provides numerous important functions, including: 1) water filtration, 2) sediment stabilization, 3) providing refuge and nursery habitat for numerous species, and 4) carbon sequestration. Benefits which could be lost if eelgrass beds continue to diminish. California has experienced some of the greatest eelgrass declines, and Morro Bay, CA experienced a 96% decrease in eelgrass from 2007 to 2017. Most studies to date have examined bottom-up …

Characterizing Predation Risk During Atlantic Salmon Smolt Migration, Matthew Mensinger

Electronic Theses and Dissertations

Salmon populations across the globe have incurred substantial declines over the last 50 years with many on the verge of extinction. Among these, the Gulf of Maine Distinct Population Segment of Atlantic salmon (Salmo salar) has declined by > 95%, and was subsequently listed under the Endangered Species Act in 2000. Once inhabiting rivers throughout New England, Maine is the last place in the United States where sea-run adults return to spawn each spring. The majority of these fish return to the Penobscot River, which has been the focus of intense restoration and research efforts over the last two …

Advancing Research And Engagement To Strengthen Ties Between Paleoenvironmental Research And Indigenous Communities, Kit M. Hamley

Electronic Theses and Dissertations

Humans and the environment have and always will be inextricably intertwined. As we move into a period of unprecedented climate and global change, it is critical that we learn from past coupled cultural-environmental systems. Paleoenvironmental science is equipped with a powerful toolkit and broad set of methodologies for examining the past and can provide important insight into complex ecosystem dynamics during periods of past change. Indigenous science/knowledge is similarly equipped with a set of methodologies (often rooted in relationships, reciprocity and responsibility) for understanding the past and making sense of the present and future. Paleoenvironmental science can also provide information …

Drivers Of Spatio-Temporal Dynamics In Long-Term Studies Of Mammal And Bird Populations In Maine, Gabriela Franzoi Dri

Electronic Theses and Dissertations

Investigating the dynamics of animal populations across large spatial and long temporal scales is fundamental to fully comprehend complex ecosystem processes since animals are responsible for many vital ecological functions including seed dispersal and vegetation regeneration. Spatial and temporal trends are particularly important in a changing world, where land-use and climate change can dramatically affect species distributions and interactions. Therefore, understanding how global change modifies populations’ structure in space and time is crucial for developing efficient conservation actions.

The goal of my dissertation is to examine the drivers of spatio-temporal distribution patterns and demographic parameters of mammal and bird populations …

Physical And Biological Responses To Climate-Driven Shifts In Greenland Lakes Across Multiple Temporal And Spatial Scales, Vaclava Hazukova

Electronic Theses and Dissertations

With amplified warming and predicted intensification of the hydrological cycle in the circumpolar North, the linkages between terrestrial and aquatic environments are changing. Yet, the impact of these alterations on Arctic terrestrial ecosystems and their functions remains uncertain. While it is evident that air temperature and precipitation do not change consistently throughout the annual cycle, ecosystem ramifications are not always examined in the context of relevant seasonal variations.

Lakes are ubiquitous across the Arctic and research over the past three decades has demonstrated their pivotal role in the Arctic carbon cycle, emphasizing their contributions as carbon sources to the atmosphere. …

Biogeochemical Consequences Of A Changing Cryosphere: Assessing Spatial And Temporal Variability In Arctic And Sub-Arctic Lake Chemistry, Ansley Grider

Electronic Theses and Dissertations

The fate of heavy metals and nutrients melting out of the cryosphere into aquatic systems is not well understood. In chapter 2 of this thesis, we addressed this knowledge gap by measuring heavy metals and nutrients in the water and sediment of four glacially-fed (GF) and four snow and groundwater-fed (SF) lakes near Kangerlussuaq, West Greenland during the summer of 2023. GF lakes had 86% higher water concentrations of nutrients -- total phosphorus (TP), NO₃^-, and NH₄⁺ -- and 137% higher concentrations of some metals -- Cd, Pb, Cr, Co, Ni, Al, Fe, Cu, Zn …

Living Dead Forests: Assessing Detrital Services In Puget Sound Pseudotsuga Menziesii Ecosystems, Forrest Becker

Capstone Collection

Coarse woody debris (CWD), the detrital result of down wood recruitment, contributes to wildlife habitat, nutrient cycling, morphological processes like soil formation, and each forest’s sense of place but if undermanaged can fuel wildfires or obstruct stakeholder use. Despite its ubiquity in Puget Sound Douglas fir (Pseudotsuga menziesii) forests in Washington, USA, few studies quantify the exact ecosystem services which down wood provides. This study seeks to understand how forest managers can estimate the ecosystem services of down wood and how human communities perceive down wood management between community, public, and private Douglas fir (P. menziesii) …

Unraveling Wetland Ecology: The Effect Of Abiotic Heterogeneity And Habitat Size On Wetland Plant Diversity In The Piedmont, Gregory T. Gilmore

All Theses

Ecosystems around the world are seeing an unprecedented decline in biodiversity. However, to better prevent this decline we cannot only understand the drivers of biodiversity loss, but also the factors that support diversity. Traditional ecological hypotheses such as the Habitat Heterogeneity Hypothesis (HHH) and the Theory of Island Biogeography (TIB) have provided frameworks for understanding biodiversity drivers. However, recent research suggests a more nuanced relationship between heterogeneity, habitat size, and diversity than previously thought. This study looks to bridge existing research gaps by examining the ecologically and conservational important habitat of wetlands. Specifically, the study focuses on the plant diversity …

Effects Of Climate Change On (Semi)-Arid Ecosystems In The Southwestern United States, Charlotte Van Der Nagel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Climate change is considered amongst the most severe threats to terrestrial and aquatic ecosystems globally. Ecosystems in the southwestern United States have specifically been impacted by intense drought conditions since 2000. Higher temperatures combined with altered precipitation stresses many ecosystems; however, ecosystem specific responses to such stressors may vary. Here, the effects of climate change on semi-arid ecosystems are analyzed for some of the most vulnerable ecosystems in the southwestern United States: lacustrine, riparian, and dryland ecosystems.

Lakes and reservoirs in arid environments often serve as drinking water sources and recreational areas where high water quality is essential. Climate change …

I’M A Forest, Not A Saltmarsh, Captain: Carbon And Sap Flow Dynamics In Coastal Forested Wetlands Of The Southeastern United States, Chris Shipway

All Theses

Coastal forested wetlands are identified as some of the highest-priority ecosystems for climate change mitigation. Here, we present two studies conducted in these unique ecosystems.

The first assessed changes in aboveground vegetative C stocks along the estuarine-riverine gradients of the Winyah Bay in South Carolina and the Savannah River in Georgia, using a space-for-time substitution to increase understanding of the impacts to upper estuarine forested wetlands from relative sea level rise. Standing C stocks on the Savannah River averaged 183.6 Mg C ha^-1, while sites on the Winyah system averaged 162.3 Mg C ha^-1. The largest …

Assessment Of Enzyme Stability In Subsurface Sediments By Computational Methods, Kambiz Kalhor

Masters Theses

The microorganisms found in marine subseafloor sediment play a vital role in global carbon and nitrogen cycles, with an estimated 2.9×10²⁹ cells, accounting for about 0.6% of Earth’s total living biomass. These microbes grow at a very slow rate, with carbon turnover occurring over the course of years to thousands of years, about six orders of magnitude slower than sulfate reducing bacteria in pure culture. These slow metabolic rates suggest that the enzymes they produce must also have extended lifespans in order to be effective over such long periods of time. As a result, these enzymes are likely to …

Influence Of Invasive Species, Drought, And Stream Permanence On Stream Crayfish Species With A Focus On The Imperiled Mammoth Spring Crayfish (Faxonius Marchandi), Leah Marie Bayer

Graduate Theses and Dissertations

Freshwater crayfish constitute one of the most-threatened taxonomic groups in North America. Invasion by other crayfish species as well as habitat degradation through alteration of natural flow regime are two of the most prominent threats to crayfish persistence. Additionally, extreme weather events like droughts can amplify threats posed by other stressors on crayfish populations and are expected to increase in frequency, magnitude, and/or duration in the future, which may negatively influence narrow-ranged endemic crayfish populations typical of the Southeast. The Mammoth Spring Crayfish, Faxonius marchandi, is a narrow-ranged endemic that occurs in the Spring River drainage of Arkansas and Missouri …

Impact Of Containment And Elevation On Created Marsh Plant Community And Ecosystem Dynamics, Kevin R. Stoner

LSU Master's Theses

Coastal marsh restoration is increasing globally, as marshes are impacted by anthropogenic impacts. Billions of dollars are allocated to marsh restoration in the Mississippi River delta where wetland loss rates are extremely high. The recovery of structural and functional attributes of created marshes varies by attribute measured and project. Here, two marshes created in 2018 and one natural marsh were used to examine how variations in hydrologic connectivity and marsh elevation influence subsurface hydrology and salinity, vegetation community structure, soil properties, accretion, and denitrification. I established a comparative field study in a created marsh contained within a higher elevation containment …

Microplastic Accumulation In The Marsh Periwinkle (Littoraria Irrorata), Sarah Keaton, Hannah Lukhard, Eli Windy, Manar Hasan

DePaul Discoveries

Contamination of oceans by microplastics (mm) currently poses a major threat to aquatic and terrestrial ecosystems worldwide. Recent attention towards this issue has raised questions about the extent to which microplastics have accumulated in the environment, and has led to an increase in studies on the effects of microplastics in various organisms. However, levels of contamination in protected natural areas are still largely unexplored, yet can offer an important empirical perspective on the issue. In addition, little is known about the potential effects of microplastics on behavior in the field. This research was conducted within the protected ACE Basin National …

Spatial Ecology Of Mountain Lions Throughout Their Distribution In California, Kyle D. Dougherty

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

Mountain lions (Puma concolor) have been studied extensively throughout their wide geographic distribution in the Western Hemisphere, but most research has been conducted at relatively small spatial scales. We used GPS telemetry data contributed by researchers in 16 study areas throughout California to advance understanding of mountain lion spatial ecology. First, we investigated multi-scale resource selection of mountain lions relative to spatially varying risk of intentional human-caused mortality associated with livestock depredation management. We show that individuals that proactively avoided mortality risk when selecting home ranges were able to relax their avoidance of risk when making resource selection …

Spatial And Abiotic Effects Of Urbanization On Small Mammal Communities, Bri Casement

Master's Theses

Urbanization, the phenomenon of increasing human population density and artificial structures, is known to decrease the richness, abundance, and diversity of native wildlife populations, fragment natural areas, and increase human and human-commensal animal interactions with wildlife. Dynamics of species persistence in habitat fragments is often understood in the framework of island biogeography theory (IBT), with habitat fragments being analogous to oceanic islands. Despite the conceptual similarities between oceanic islands in IBT and urbanized habitat fragments (fragment size, fragment age, and distance to immigration sources), there are important differences. In urban fragments, the matrix is not completely impassible, habitats within fragments …

Spatial Ecology Of Mountain Lions Throughout Their Distribution In California, Kyle Duncan Dougherty

Dissertations and Doctoral Documents from University of Nebraska-Lincoln, 2023–

Mountain lions (Puma concolor) have been studied extensively throughout their wide geographic distribution in the Western Hemisphere, but most research has been conducted at relatively small spatial scales. We used GPS telemetry data contributed by researchers in 16 study areas throughout California to advance understanding of mountain lion spatial ecology. First, we investigated multi-scale resource selection of mountain lions relative to spatially varying risk of intentional human-caused mortality associated with livestock depredation management. We show that individuals that proactively avoided mortality risk when selecting home ranges were able to relax their avoidance of risk when making resource selection …

The Relationship Between Changing Land Cover And Benthic Macroinvertebrate Diversity In Choccolocco Creek, Northeast Alabama, Kindall Brown

Theses

Land cover changes, driven by urbanization, agriculture, and deforestation, significantly affect the physical and chemical characteristics of water bodies at both the watershed and riparian levels. At the larger spatial scale, a stream’s surrounding watershed facilitates lateral inputs into the stream that are essential for biodiversity support, hydrological stability, and water quality. When a stream becomes disconnected from the lateral inputs due to urban or agricultural development, the morphology of the stream is significantly altered. On a smaller spatial scale, the riparian zone can act as a buffer to pollutants. The vegetation surrounding the stream bank promotes stability to the …

New Insights On Hybridization In Potamogeton Floridanus (The Florida Pondweed)), Kaitlyn R. Sampson

<strong> Theses and Dissertations </strong>

Freshwater ecosystems are some of the most important and highest threatened habitats in the world, and aquatic plants play an important, but often-overlooked, role in maintaining them. Potamogeton is a diverse and ecologically important aquatic plant genus well known for taxonomic difficulty and rampant hybridization. lbis study aimed to 1) test the hypothesis that Potamogeton jloridanus (Florida pondweed) is a hybrid between P. oakesianus and P. pulcher, and 2) to investigate correlations in ecological conditions for the focal species. This study revealed the discovery of a new population of P. jloridanus in Big Coldwater Creek in Santa Rosa Co., FL, …

Behavioural Distributions Of Macrophytes In An Oxbow Lake, Dhir Beel With Reference To Its Water Quality In Assam, India, Arup Nama Das, D. K. Sharma

Journal of Bioresource Management

An Oxbow lake, Dhir Beel, situated in Western Assam, India, stands as a habitat for a plethora of plant and animal species, nurturing a vibrant ecosystem within its freshwater environs. This study sought to address concerns surrounding pollution, encroachment, siltation, and overfishing within Dhir Beel. Over a span of three years (2016-2019), samples were meticulously collected from five distinct sites to analyze both water quality and macrophyte populations. Employing the APHA method, the physico-chemical parameters of the water were evaluated, while a comprehensive identification process was undertaken to categorize the macrophytes. These aquatic plants, spanning dicots, monocots, and pteridophytes, were …