Digital Commons Network^™

Mechanical Harvesting Effectively Controls Young Typha Spp. Invasion And Unmanned Aerial Vehicle Data Enhances Post-Treatment Monitoring, Shane Lishawa, Brendan D. Carson, Jodi S. Brandt, Jason M. Tallant, Nicholas J. Reo, Dennis A. Albert, Andrew M. Monks, Joseph M. Lautenbach

School of Environmental Sustainability: Faculty Publications and Other Works

The ecological impacts of invasive plants increase dramatically with time since invasion. Targeting young populations for treatment is therefore an economically and ecologically effective management approach, especially when linked to post-treatment monitoring to evaluate the efficacy of management. However, collecting detailed field-based post-treatment data is prohibitively expensive, typically resulting in inadequate documentation of the ecological effects of invasive plant management. Alternative approaches, such as remote detection with unmanned aerial vehicles (UAV), provide an opportunity to advance the science and practice of restoration ecology. In this study, we sought to determine the plant community response to different mechanical removal treatments to …

The Role Of Adult Fiddler Crab Environmental Acoustic Cues And Chemical Cues In Stimulating Molting Of Field-Caught Megalopae, Emily E. Waddell, Wendy Dow Piniak, Kathleen A. Reinsel, James M. Welch

Student Publications

In mid-Atlantic estuaries, three fiddler crab species, Uca pugilator, Uca pugnax and Uca minax co-occur, with their adults occupying different habitat types distinguished by salinity and sediment size. Some evidence exists that selective settlement is responsible for this separation but the mechanism is largely unknown. We tested the hypothesis that field-caught megalopae would accelerate metamorphosis in the presence of adult species-specific environmental acoustic cues and conspecific chemical cues. We placed megalopae in seawater with and without adult chemical cues, exposed them to one of three sound treatments for 8 days, and recorded the time each megalopa took to metamorphose. In …

Changes In The Breeding Range Of The Broad-Winged Hawk (Buteo Platypterus) Due To Habitat Fragmentation In The Northern Appalachian Region, Rachael M. Pruitt

Student Publications

The Broad-winged Hawk (BWHA), Buteo platypterus, a small, secretive hawk with distinguishing broad black tail bands, breeds in northeastern North America. The hawks nest in deciduous or mixed forest, often near water, and close to clearings or forest edges. Land conversion and fragmentation alters the landscape and reduces the area of contiguous forest used by BWHA. This study seeks to determine the habitat metrics that may be influencing the apparent breeding range declines of the BWHA at the landscape scale. Landscape characteristics and BWHA presence data from 18,684 Breeding Bird Atlas blocks (each about 25km2) from Ohio, West Virginia, Maryland, …

Bioethics In The Work Of Ernest Everett Just: + Missing - Some 400 Pages, Theodore Walker

Perkins Faculty Research and Special Events

Biology + ethics = bioethics. Here we see that Howard University biologist Ernest Everett Just (born 1883, died 1941) connected biology to ethics.

According to Just, various forms of specific biology (including especially cell biology) plus “general biology” are necessary for explaining adequately the origin of ethical behaviors. Social ethical behaviors, especially mutual aid and cooperative interactions with others and the environment, are essential to evolutionary advances among living creatures, ranging from humans to cells. Accordingly, theory of ethics (moral theory) should have roots in biology.

Also, Just wrote an unpublished book-length manuscript—“some 400 typed pages” (Just 1940)—on seeking the …

Nitrogen Sustainability: Impediments To Action And Communication, Eric E. Jorgensen

Journal of Environmental Sustainability

“Sustainability” is widely used to imply the presence of explicit consideration of environmentally friendly needs and that high societal-value is placed on those needs. However, it is abundantly clear after 30 years that talking about sustainability and achieving it are two entirely different things. The core concept underlying sustainability is that current human practices and activities be conducted so as to not degrade prospects for future generations. With nitrogen, conflicts about sustainability in-theory and sustainability in-practice are close to the surface because of nitrogen’s central role in food production and economic activity. Measures of nitrogen inputs commonly range as high …

Coral Bleaching And The Effect Of Disturbances On The Damselfish Community On Lizard Island, Australia, Alejandra Munoz

Independent Study Project (ISP) Collection

Coral reefs are characterized by their dynamic ecological processes that supports a high diversity through the recruitment of marine species and temporal disturbances that can have positive effects on the system. In the face of global climate change however, coral reefs face intense coral bleaching and increased degradation as they may begin to have less time to recover between bleaching events in the near future. Little is known on the long term effects of coral bleaching and habitat degradation on reef fish communities and much less is known about the mechanisms that bring about changes to reef fish assemblages.

This …

Characterization Of Legacy Sediment Variations In Accretion And Carbon Dynamics Following Dam Removal In A Recently Restored Tidal Freshwater Wetland, Melissa J. Davis, Christopher D. Gatens, Edward R. Crawford, Arif Sikder

Rice Rivers Center Research Symposium

Damming disrupts the natural flow of sediment to adjoining water bodies resulting in the accumulation of Legacy Sediments (LS). While the impact of LS inputs has been well investigated in lotic Mid-Atlantic piedmont stream restorations, (i.e. milldam removal 1,2,3,4,5,), there have been few studies investigating LS following dam removal in low-gradient coastal plain streams. The objectives of this study were to quantify spatial and temporal variations of LS characteristics in a low-gradient tidal stream restoration within the lower James River watershed. Secondary objectives were to assess the current temporal and spatial variability in sediment deposition within the recently restored Kimages …

Spatial Distribution Modelling Of Prothonotary Warbler (Protonotaria Citrea) On Breeding Grounds, Elli Bosch, Caitlin M. Vigneau, Rolang Piocuda, Catherine Viverette, Jessica Reese

Rice Rivers Center Research Symposium

Ecological niche modeling is used to predict a species’ distribution in a geographic area based on abiotic and biotic variables. Understanding a species’ range is important for conservation and restoration efforts. As anthropogenic forces may alter or deplete habitat, it is important to know the ecological requirements of a species to understand how and what habitat to protect. With the increasing threat of climate change and rising temperature and precipitation, the suitable habitat and the distribution for many species is expected to shift. Migratory species are particularly at risk of these changes as they require suitable habitat not only on …

Offspring Sex Ratio In Double Brooding Prothonotary Warblers, Radleigh Herschel, Anthony G. Kouri, Rebecca Vareed, Stephanie Warshawsky, Matthew Desaix

Rice Rivers Center Research Symposium

Prothonotary warblers are bright, golden birds who, with their loud calls, make themselves known in wetland habitats in the spring after returning from their winter homes in the Neotropics to breed. This migratory species is important to study because of their need for these habitats and are declining in population due to the degradation of wetland environments across the western hemisphere.

VCU started a project in 1987 to study prothonotary warblers including population genetics, breeding biology, and migration ecology. Since then, with the help of Richmond Audubon Society, the project has erected over 600 nesting boxes along the James River …

The Effects Of Inorganic Nitrogen And Phosphorus Enrichment On Herbaceous Species Growth Of The Kimages Creek Wetland (Va), Kristen Burton, Scott C. Neubauer

Rice Rivers Center Research Symposium

Dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) infiltrate waterways through fertilizer application, urban stormwater runoff, and sewer infrastructure leaks. As surrounding waterbodies experience increased DIN and DIP inputs, wetlands can experience corresponding nutrient enrichment. Vegetation uses DIN and DIP for structural growth, color, and seed production. Changes in DIN and DIP availability can influence species distribution due to differences in photosynthetic rates, root morphology and structure, and tissue type.

DIP and DIN inputs are projected to increase 15-30% and 30-60% in the next fifty years¹. It is of interest to examine plant growth characteristics within this nutrient enrichment …

Evaluating Trophic Rewilding As A Conservation Technique, Aaron Sieve

Biology: Student Scholarship & Creative Works

The focus for this paper is to define specifically trophic rewilding, determine its efficacy as a conservation technique, and explore ways to lessen one of its key limitations. Trophic rewilding is the conservation technique whereby an extirpated keystone species or ecosystem engineer is reintroduced into a degraded habitat to restore ecological function by triggering trophic cascades. The technique is evaluated through analysis of the concepts of trophic cascades and ecosystem engineers. Key limitations of trophic rewilding are that a lack of population control in reintroduced may cause issues, that many times not enough is known about trophic cascades to be …

Mapping The Missouri, Becca Krasky

Sustainable RIVER

No abstract provided.

Biophysical Drivers Of Carbon Dioxide And Methane Fluxes In A Restored Tidal Freshwater Wetland, Ellen Stuart-Haëntjens, Scott C. Neubauer, William Shuart, Christopher M. Gough

Rice Rivers Center Research Symposium

Wetlands store large amounts of carbon (C) in biomass and soils, playing a crucial role in offsetting greenhouse gas (GHG) emissions; however, they also account for 30% of global yearly CH4 emissions. Anthropogenic disturbance has led to the decline of natural wetlands throughout the United States, with a corresponding increase in created and restored wetlands. Studies characterizing biogeochemical processes in restored forested wetlands, particularly those that are both tidal and freshwater, are lacking but essential for informing science- based carbon management.

Identifying Biotic Determinants Of Historic American Eel (Anguilla Rostrata) Distributions, Taylor E. Woods, Daniel J. Mcgarvey

Rice Rivers Center Research Symposium

Traditionally, ecologists studying large scale patterns in species distributions emphasize abiotic variables over biotic interactions. Noting that both abiotic & biotic variables likely determine distributions of all organisms, many ecologists now aim for a more comprehensive view of species distributions, inclusive of both abiotic and biotic components (Soberón 2007).

Local Scale Comparisons Of Avian And Woody Vegetation Communities Within Four Arkansas State Parks, Bennett P. Grooms, Rachael E. Urbanek

Journal of the Arkansas Academy of Science

Measuring the spatial distribution of biotic communities can provide useful data to wildlife managers on how and why species assemblages differ across a landscape. During 18 May – 7 August 2015, we conducted avian point counts and collected vegetation data in nested subplots at 4 Arkansas state parks. We then used a series of one-way ANOVAs and Kruskal-Wallis tests to examine differences in species richness, Simpson’s evenness, Simpson’s diversity, and Bray-Curtis similarity across the 4 parks. Mount Magazine State Park had the lowest avian evenness (F_3,22 = 9.57 P = 0.003) and diversity (F_3,22 = 17.8 …

The Effects Of Thermal Stress On Fluorescent Protein Expression In An Indo-Pacific Scleractinian Coral Species, Acropora Tenuis, Anna Knochel

Independent Study Project (ISP) Collection

The scleractinian coral species that so heavily define tropical coral reefs are increasingly threatened by anthropogenic global warming. Rising sea surface temperatures in combination with light stress causes the photosynthetic breakdown of the coral’s algal symbiont, Symbiodinium. Corals have developed a number of physiological responses to handle acute stressors, such as the production of ultraviolet-protecting amino acids, heat shock proteins, the ability to shift symbionts, and the production of fluorescent proteins. The latter has been thought to play a photoprotective role in the coral holobiont, and studies have shown evidence that corals orient these pigments to divert harmful light away …

Sample Collection And Dna Extraction Methods For Environmental Dna Metabarcoding In Headwater Streams, Michael Triston Mullins

Online Theses and Dissertations

DNA is found to be free and ubiquitous in the environment where it is no longer associated with the source organism, and is also known as environmental-DNA (eDNA). Methods optimized for specific environments may be able supplement insight to local taxa richness. With the advent of high throughput sequencing and the proliferation of sequence data in public repositories, insights to the biodiversity of communities at the molecular level have been possible. Thus, this study compared commonly used DNA capture (water precipitation and filtration) and extraction (MoBio's PowerWater, Qiagen's DNeasy Blood and Tissue Kit, and a CTAB protocol) methods in their …

Short-Term Effects Of Nutrients On A Barrier Island Grassland Community, Ashley Moulton

Theses and Dissertations

Increased nutrient availability globally has the potential to affect community functional composition of plants in nutrient limited environments, such as coastal grassland systems. Stability of these systems are threatened worldwide by urbanization, as well as effects of sea level rise and increased frequency and intensity of storms, and atmospheric N deposition, associated with climate change. Annual net primary productivity (ANPP), species composition, and functional traits (community weighted specific leaf area (CWSLA), leaf area index (LAI), growth form and photosynthetic pathway) were measured across four treatments to assess multiple resource limitation of nitrogen (N) and phosphorus (P) and functional community response …

Effects Of Prescribed Fire On Cope’S Gray Treefrog (Hyla Chrysoscelis) Across Habitat Scales And Life Stages, Logan Mcdonald

Theses and Dissertations

Fire may alter both aquatic and terrestrial habitat used by all amphibian life stages, yet, our knowledge of its effects on amphibians is primarily limited to adult responses. I present an integrated approach to test the response of Cope’s Gray Treefrog (Hyla chrysoscelis) to fire by examining responses in tadpole performance and survivorship, adult abundance, and oviposition. Tadpoles raised with burned leaf litter had similar survival, but total mass and total length were 440% and 170% greater, respectively, for tadpoles raised in unburned litter. I assessed terrestrial and aquatic oviposition cues by embedding burned and unburned litter treatments within burned …

A Comparison Of Computational Methods For Estimating Estuarine Production And Respiration From Diel Open Water Dissolved Oxygen Measurements, Spencer Tassone

Theses and Dissertations

Diel dissolved oxygen (DO) data were used to characterize seasonal, inter-annual, and longitudinal variation in production and respiration for the James River Estuary. Two computational methods (Bayesian and bookkeeping) were applied to these data to determine whether inferences regarding DO metabolism are sensitive to methodology. Net metabolism was sensitive to methodology as Bayesian results indicated net heterotrophy (production < respiration) while bookkeeping results indicated net autotrophy (production > respiration). Differences in net metabolism among the methods was due to low seasonal variation in respiration using the Bayesian method, whereas bookkeeping results showed a strong correlation between production and respiration. Bayesian results suggest a dependence on allochthonous organic matter (OM) whereas …

A Range-Wide Assessment Of Migratory Connectivity For The Prothonotary Warbler Using Stable Hydrogen Isotopes, Jessica Reese

Theses and Dissertations

Populations of many species of migratory birds are declining, and an understanding of how populations are linked between the breeding and nonbreeding grounds is necessary in order to determine drivers of declines. While all current tracking technologies to study the movements of small songbirds are limited by their coarse resolution, tracking birds by measuring stable isotopes in keratin offers an advantage because it requires only a single capture and is cost-effective, which leads to robust sample sizes. While this tracking method is accurate, stable hydrogen isotope values measured in feathers (δ²H_f) are known to be variable …

The Effect Of Chronic Nutrient Addition From Wastewater On Forest Ecosystems At The Rice Rivers Center, Michael Beck

Theses and Dissertations

Wastewater application to land can be a useful tool for mitigating impacts of nutrient enrichment on aquatic systems. A land application treatment system at VCU’s Rice Rivers Center in Charles City County, VA provided an opportunity to study the impact of wastewater addition on the biogeochemistry of forests representative of the Mid-Atlantic Coastal Plain. Nutrient concentrations in throughfall and leachate were measured at Treatment and Control sites to assess differences in nutrient deposition and retention. Wastewater amended plots from the Walter L. Rice education building received 20-fold (N) and 6-fold (P) higher inputs relative to Control plots and plots located …

Limited Evidence For Co2-Related Growth Enhancement In Northern Rocky Mountain Pinus Contorta Populations: Trends In Growth And Intrinsic Water-Use Efficiency Across Climate Gradients, Charlotte C. Reed

Graduate Student Theses, Dissertations, & Professional Papers

Forests sequester large amounts of carbon annually; however, the degree to which enhanced forest productivity is due to more conducive climate or CO₂ fertilization remains uncertain. Increasing atmospheric CO₂ may enhance photosynthesis and/or decrease stomatal conductance thereby enhancing intrinsic water use efficiency (iWUE). While increasing iWUE has been observed in most trees globally, this increase does not necessarily translate into greater growth. This study aims to evaluate whether responses of radial growth and iWUE to increasing CO₂ vary across climatic gradients. To investigate interactions between climate and CO₂ and their impacts on tree physiology and growth, …

A Comparative Analysis Of Geometric Morphometrics Across Two Pseudemys Turtle Species In East Central Virginia, Kristin C. Dillard

Theses and Dissertations

The phylogeny of the turtle genus Pseudemys is poorly understood. In Virginia, many turtles have been found with indicator traits of both eastern river cooters (Pseudemys concinna concinna) and northern red bellied cooters (Pseudemys rubriventris). This study explores morphological evidence for hybridization between the two species across three riverine sites in east central Virginia.

Museum voucher groups for each species were analyzed for relative shell height and plastron length. The shape of the plastral scutes and upper jaw were analyzed using landmark-based morphometric software. These metrics were compared with measurements taken from 188 field-caught Pseudemys specimens. …

Quantifying Current Sediment Deposition, Legacy Sediments, And Pre-Impoundment Vertical Accretion And Carbon Dynamics Following Dam Removal In A Recently Restored Tidal Freshwater Wetland, Melissa J. Davis

Theses and Dissertations

Damming disrupts natural sediment flow to downstream resulting in legacy sediment accumulation. Legacy sediments have been well investigated in streams throughout the Piedmont region; however, there is no research of legacy sediments following dam removal in low-gradient Coastal Plain streams. Research objectives were to: characterize legacy sediments in a low-gradient stream restoration, quantify pre-impoundment accretion and carbon dynamics, and assess current sediment deposition rates via ¹⁴C analyses within sediment cores and sediment collection tiles. Carbon accumulation and accretion rates of modern tidal sediment have reached that of the tidal relic benchmark and current sediment deposition rates are similar between …

Behavioral Responses Of Sub-Adult Atlantic Sturgeon (Acipenser Oxyrinchus Oxyrinchus) To Electromagnetic And Magnetic Fields Under Laboratory Conditions, Andrew Mcintyre Iii

Theses and Dissertations

Electromagnetic fields (EMF) produced by high voltage (HV), submarine transmission cables leading from offshore wind energy generation facilities could affect foraging or migratory behaviors of electro-receptive fishes, including endangered Atlantic Sturgeon. However, no published studies have quantitatively evaluated the possible behavioral effects of EMF exposure on sturgeon during residence in coastal waters. This study evaluated behavioral responses by sub-adult Atlantic Sturgeon to electromagnetic and magnetic fields under controlled laboratory conditions. Fabricated EMF generators were used to emulate a range of field EMF conditions that migratory fishes could encounter in proximity to submarine HV sources. Sensor arrays and digital video recorders …

Evolutionary Dynamics Of Tree Invasions: Complementing The Unified Framework For Biological Invasions, Rafael D. Zenni, Ian A. Dickie, Michael J. Wingfield, Heidi Hirsch, Casparus J. Crous, Laura A. Meyerson, Treena I. Burgess, Thalita G. Zimmermann, Metha M. Klock, Evan Siemann, Alexandra Erfmeier, Roxana Aragon, Lia Montti, Johannes J. Le Roux

Faculty Publications, Environmental Studies

Evolutionary processes greatly impact the outcomes of biological invasions. An extensive body of research suggests that invasive populations often undergo phenotypic and ecological divergence from their native sources. Evolution also operates at different and distinct stages during the invasion process. Thus, it is important to incorporate evolutionary change into frameworks of biological invasions because it allows us to conceptualize how these processes may facilitate or hinder invasion success. Here, we review such processes, with an emphasis on tree invasions, and place them in the context of the unified framework for biological invasions. The processes and mechanisms described are pre-introduction evolutionary …

Effects Of Non-Consumptive Recreation And Environmental Factors On Arkansas State Park Biodiversity, Bennett P. Grooms

Theses and Dissertations from 2016

State parks serve a dual conservation role by offering protected habitat to many species while also promoting recreational use of natural resources. Non-consumptive recreation activities, however, have long-term negative effects on the behavior, physiology, and reproductive success of state park biotic communities. The purpose of my research was to investigate the possible synergistic effects of non-consumptive trail use, environmental factors, and trail design factors on avian, mesocarnivore, and woody vegetation communities in Arkansas state parks. During 18 May – 7 August 2015, I conducted avian point counts, trail user counts, set camera traps, and sampled vegetation at 227 points on …

Review Of Plants Have So Much To Give Us, All We Have To Do Is Ask: Anishinaabe Botanical Teachings By Mary Siisip Geniusz (Edited By Wendy Makoons Geniusz, Illustrated By Annmarie Geniusz), Natasha Myhal, Kelly Kindscher

The Prairie Naturalist

Plants Have So Much to Give Us, All We Have to Do Is Ask offers a new look at Anishinaabe (Ojibwe) ethnobotany as told through traditional stories. Botanical teachings through stories are a way to pass down traditional knowledge from generation to generation. For example, Anishinaabe knowledge on plants was written and recorded in communities willing to share their knowledge with early scholars, such as Albert B. Reagan (1928), Huron H. Smith (1932), and Melvin R. Gilmore (1933). Each of these scholars spent time with an Anishinaabe community to learn about plants and primarily to provide written descriptions of plants …

Reproductive Success Through High Pollinator Visitation Rates Despite Self Incompatibility In An Endangered Wallflower, Miranda K. Melen, Julie A. Herman, Jessica Lucas, Rachel E. O’Malley, Ingrid M. Parker, Aaron M. Thom, Justen B. Whittall

Biology

PREMISE OF THE STUDY: Self incompatibility (SI) in rare plants presents a unique challenge—SI protects plants from inbreeding depression, but requires a sufficient number of mates and xenogamous pollination. Does SI persist in an endangered polyploid? Is pollinator visitation sufficient to ensure reproductive success? Is there evidence of inbreeding/outbreeding depression? We characterized the mating system, primary pollinators, pollen limitation, and inbreeding/outbreeding depression in Erysimum teretifolium to guide conservation efforts.

METHODS: We compared seed production following self pollination and within- and between-population crosses. Pollen tubes were visualized after self pollinations and between-population pollinations. Pollen limitation was tested in the field. Pollinator …