Life Sciences Commons^™

Modular Structure In Fish Co-Occurrence Networks: A Comparison Across Spatial Scales And Grouping Methodologies, Daniel Mcgarvey Dr., Joseph Veech

Environmental Studies Publications

Network modules are used for diverse purposes, ranging from delineation of biogeographical provinces to the study of biotic interactions. We assess spatial scaling effects on modular structure, using a multi-step process to compare fish co-occurrence networks at three nested scales. We first detect modules with simulated annealing and use spatial clustering tests (interspecific distances among species’ range centroids) to determine if modules consist of species with broadly overlapping ranges; strong spatial clustering may reflect environmental filtering, while absence of spatial clustering may reflect positive interspecific relationships (commensalism or mutualism). We then use non-hierarchical, multivariate cluster analysis as an alternative method …

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.

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 …

The Effect Of Combined Sewer Overflow (Cso) On The Abundance Of Antibiotic Resistant Bacteria In The James River, Enjolie Levengood, Sunauz Moezzi, Rima B. Franklin

Rice Rivers Center Research Symposium

Antibiotics have been used to treat bacterial infections worldwide since their discovery in the early 20th century and are vital to human health. Unfortunately, the heavy use of antibiotics has led to the increased natural selection of antibiotic resistant bacteria. In urban rivers, the spread of resistance resistance is through through the direct acquisition of resistance genes by either either either cell-to -cell contact or DNA uptake via a process called horizontal gene transfer transfer(HGT) 2.HGT, resistance genes, and resistant bacteria are in greater abundance in wastewater systems, and are released into the environment in wastewater plant effluent2,3. One problematic …

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 …

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).

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 Inception Of A Long-Term Study Of Elevation Change And Sediment Accretion In Three Forested Tidal Freshwater Wetlands And In The Restored Freshwater Marsh At Kimages Creek, Ronaldo Lopez, Edward R. Crawford, Scott C. Neubauer, Jessica Anne Powell, Sean Weber

Rice Rivers Center Research Symposium

Sediment accretion and the corresponding ability to keep pace with sea level rise in both mature forested tidal freshwater wetlands and restored wetland sites represent significant data gaps in the current body of literature pertaining to wetland sustainability. In order to address these data gaps, Surface Elevation Tables (SETs) were installed along with feldspar marker horizons to measure contemporary sediment accretion rates in three mature forested tidal freshwater wetlands, as well as accretion within a tidal marsh currently undergoing restoration. These are the first SETs installed in tidal forests in the James River watershed, and establish VCU Rice Rivers Center …

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 …

Characterization Of Current And Historical Variations In Sediment Accretion And Carbon Dynamics At The Rice Rivers Center Kimages Creek Wetland Restoration, Melissa J. Davis, Christopher D. Gatens, Edward R. Crawford, Arif Sikder

Rice Rivers Center Research Symposium

Current research of freshwater wetland soils have assessed and reported smaller stocks of soil organic carbon in restored wetlands compared to reference natural wetlands. However, a majority of these studies focus on sites restored from agricultural draining of non-tidal depressional wetlands,whereas carbon and accretion dynamics in tidal freshwater wetlands restored via dam removal is poorly understood. The U.S. Army Corps of Engineers estimates over 80,000 dams greater than 6 feet and tens of thousands of smaller dams pepper the U.S., of which the majority are unsafe, old or no longer serve their intended purpose. Damming disrupts the natural flow of …

An Analysis Of Particulate Matter In Central Virginia, Elizabeth Garrett, Arif Sikder

Rice Rivers Center Research Symposium

Virginia is consistently rated as a state with high rates of asthma (Asthma and Allergy Foundation 2014). Although this respiratory disease has many causes, certain air pollutants can be a trigger. The EPA currently identifies, monitors, and regulates seven types of air pollutants. One of these pollutants, particulate matter, can occur both naturally and culturally. The primary anthropogenic cause of particulate matter is fly ash, which is formed during fossil fuel combustion. Different technology installed in the power plant can capture some of the fly ash but these methods are not entirely effective.

This study focused on estimating the ratio …

Assessing How Disruption Of Methanogenic Communities And Their Syntrophic Relationships In Tidal Freshwater Marshes Via Saltwater Intrusion May Affect Ch4 Emissions, David J. Berrier, Scott C. Neubauer, Rima B. Franklin

Rice Rivers Center Research Symposium

Tidal freshwater wetlands (TFW), which lie at the interface of saltwater and freshwater ecosystems, are predicted to experience moderate salinity increases due to sea level rise. Increases in salinity generally suppress CH4 production, but it is uncertain to what extent elevated salinity will affect CH4 cycling in TFW. It is also unknown whether CH4 production will resume when freshwater conditions return. The ability to produce CH4 is limited to a monophyletic group of the Euryarchaeota phylum called methanogens (MG), who are limited to a small number of substrates (e.g., acetate, H2, and formate) produced from the breakdown of fermentation products. …

Wood Frog And Spotted Salamander Abundance Across Pool Types And Wetland Networks At Fort A.P. Hill, Va, Logan Mcdonald, Will Fields, Katelyn Horn, James R. Vonesh, Kristine Grayson

Rice Rivers Center Research Symposium

Effective management of pond breeding amphibians requires identifying suitable breeding habitat and its use by different species. Suitable breeding habitat is largely characterized by pool type, physical habitat, and position within the landscape. Parameters such as vegetative cover, hydrology, and water chemistry are known to influence amphibian occupancy of vernal pools. While seasonal vernal pools have been the focus of conservation efforts, pools that are an artifact of anthropogenic disturbance, such as road ruts, may be an important component of the landscape for amphibians. The role of wetland isolation within a landscape has been well studied, but less consideration has …

Effects Of Olfactory Cues On The Foraging Behavior Of A Carabid Beetle, Calosoma Wilcoxi, A Predator Of A Forest Defoliator., Kennesha J. Myrick-Bragg, Karen Kester, Derek M. Johnson

Rice Rivers Center Research Symposium

Arthropod predators use environmental cues such as kairomones to locate herbivore prey. Several species have been shown to be attracted to volatiles emitted by herbivore host plants, as well as olfactory cues produced by the herbivore. Calosoma wilcoxi is a voracious predator that specializes on lepidopteran larvae often found in the forest canopy, showing a preference for the fall cankerworm. It is unknown whether C. wilcoxi uses olfactory cues associated with prey or their host plants to locate foraging sites.

The objective of this study is to use fall cankerworm frass, caterpillars, damaged oak leaves, and conspecifics to determine if …

Tower-Based Greenhouse Gas Fluxes In A Restored Tidal Freshwater Wetland: A Shared Resource For Research And Teaching., Ellen J. Stuart-Haëntjens, Scott C. Neubauer, Christopher M. Gough

Rice Rivers Center Research Symposium

The goals of this study are: 1) to use an eddy-covariance system to continuously measure wetland-atmosphere CO2 and CH4 exchange in a restored forested wetland, 2) to quantity C sequestration in plant biomass and soils in restored (Kimages Creek watershed) and old-growth (Harris Creek watershed) forested wetlands, and 3) to establish a shared long-term, shared research and teaching platform centered on eddy-covariance tower measurements. Since the old-growth forest wetland has had longer to accumulate C, the current C stocks are likely much larger than those of the restored wetland; however, the rate of C accumulation (i.e., C sequestration or net …

Greenhouse Gas Emissions Over A Tidal Cycle In A Freshwater Wetland, Joseph C. Morina, Rima B. Franklin

Rice Rivers Center Research Symposium

Tidal freshwater wetlands are located at the interface of non-tidal freshwater riverine systems and estuarine tidal systems. These habitats experience freshwater tides, creating unique redoximorphic soil characteristics while simultaneously presenting an opportunity for hydrologic nutrient transport into the system. Because of this periodic flooding and draining, tidal freshwater wetlands are systems of intense biogeochemical transformations, which are microbially mediated. Several microbial transformations (e.g., methanogenesis, incomplete denitrification, and nitrification) result in the production of greenhouse gases (CO2, CH4, and N2O) at globally-significant levels. For example, wetlands are one of the greatest sources of methane on Earth, accounting for 20-33% of the …

Using The Past To Restore The Future: Quantifying Historical Vegetation To Assist In Tidal Freshwater Wetland Restoration, Christopher D. Gatens, Richard Ward, Edward R. Crawford

Rice Rivers Center Research Symposium

Wetlands have been providing humans with critical natural ecosystem services throughout our time on Earth. Nevertheless, these invaluable ecosystems have been habitually altered as a cost of human progression. Two of the most common alterations to wetlands are hydrologic, in the form of damming, and filling. Both occurred along Kimages Creek in Charles City County, VA during the 19th and 20th centuries. In 2010 the Lake Charles dam was partially removed, restoring the creek's tidal communication with the James River and beginning tidal forested freshwater wetland restoration. Upon the recession of the body of water, numerous woody stumps were revealed.

A Baseline Study Of Edaphic Characteristics, Vegetation Structure, And Recruitment Of Native Baldcypress (Taxodium Distichum (L). Rich. Var. Distichum) In The Newly Restored Wetland Of The Vcu Rice Rivers Center, Melissa J. Davis, Matthew S. Schibner

Rice Rivers Center Research Symposium

In theory, the ideal of ecological restoration is to reestablish a completely functioning ecosystem, however restoration success is often elusive (Stanturf et al. 2001). There is a significant gap in the current research on the impacts of restoration management of restored wetlands on ecosystem functions, especially biogeochemical cycling (Bernal & Mitsch 2013). Furthermore, there are many questions about management techniques when it comes to ecological engineering versus self-design (Bernal & Mitsch, 2013). However, we do know that it is critical to understand the species' life history, habitat template, and spatio temporal scope when attempting to re-establish populations (Lake et al. …

Using The Past To Restore The Future: Quantifying Historical Vegetation To Assist In Tidal Freshwater Wetland Restoration Former Lake Charles At The Vcu Rice Rivers Center, Christopher D. Gatens, Edward R. Crawford

Rice Rivers Center Research Symposium

Wetlands have been providing humans with critical natural ecosystem services throughout our time on Earth. Nevertheless, these invaluable ecosystems have been habitually altered as a cost of human progression. Two of the most common alterations to wetlands are hydrologic, in the form of damming, and filling. Both occurred along Kimages Creek in Charles City County, VA during the 19th and 20th centuries. In 2010 the Lake Charles dam was partially removed, restoring the creek's tidal communication with the James River and beginning tidal forested freshwater wetland restoration. Upon the recession of the body of water, numerous woody stumps were revealed.

Behavioral Observations: Foraging And Aggression Of Neotropical Migrants And Resident Birds In Panama, Jessica M. Johnston, Samuel B. King, Ryan A. Levering

Rice Rivers Center Research Symposium

Lyons suggests that foraging data in songbirds can be an indicator of food abundance, with higher attack rate= higher habitat quality; higher foraging speed= lower habitat quality (2005). Territorial behavior such as interspecific aggression among songbirds may also be related to food availability. Previous studies have documented variation in the extent of territorial and aggressive behaviors among resident and Neotropical migratory species on tropical wintering grounds. This research gathered foraging and aggression data at two coastal angroves sites in central Panama, one on the Caribbean Coast (Galeta) and one on the Pacific Coast (Juan Diaz-East). Foraging data was used an …

Communicating The Overall Experience Of Research Through Various Approaches Using Art: A Case Study Of The Prothonotary Warbler, Hannah Huddle, Lesley P. Bulluck, Sarah E. Faris

Rice Rivers Center Research Symposium

Recommended Citation

In general, scientific research has publication of data as the end goal. The process and experience, which are of great importance in art disciplines, is not necessarily represented or valued. However, science has an inherent element of art to it, which deserves to be shown. I have been studying Prothonotary Warblers with a team from the VCU Biology Department to learn how I can reinterpret the research in a way that bridges the gap between the experience and typical scientific products. The research team measured spatial and temporal variation in warbler prey abundance (caterpillars and mayflies) and assessed …

Emergent Non-Consumptive Predator Effects Alter Habitat Colonization By Mosquitoes, Ethan G. Staats, Salvatore J. Agosta, James R. Vonesh

Rice Rivers Center Research Symposium

Top-down consumptive control (suppression) is an important driver of populations and communities of prey organisms. Diverse predator assemblages often yield non-linear suppression with respect to constituent species' effects (emergence); most often diversity enhances suppression. Predators also affect prey organisms non-consumptively through changes in prey physiological, physical, spatial, temporal, and behavioral responses to predators. Role of predator diversity in non-consumptive response by prey is relatively un-studied. Role of predator diversity in shaping prey populations and communities through habitat colonization is a novel question.

Vegetation Structure Of Mangrove Ecosystems In Panama, Christopher L. Arrington, Cole Gandee, Spencer R. Parkinson

Rice Rivers Center Research Symposium

Mangroves provide important habitat for terrestrial and marine wildlife. They buffer shorelines from flooding and sequester excess nutrients and pollutants in runoff before reaching rivers and oceans. Mangroves provide a wintering habitat for migratory bird species. These habitats are being rapidly lost to coastal development. This research focused on assessing the vegetation structure of mangrove ecosystems in Panama.

Algal Toxins In The Food Chain – A Comparative Study Of Chesapeake Bay And Baltic Coastal Food Webs, Spencer Tassone, Jūratė Lesutienė, Zita Gasiūnaitė, Linas Ložys, Renata Pilkaitytė, Žilvinas Pūtys, Paul A. Bukaveckas

Rice Rivers Center Research Symposium

Microcystin (MC) is a hepatotoxin produced by cyanobacteria (blue-green algae) which is found globally in eutrophic waters including lakes, lagoons and estuaries (Paerl and Paul 2012). The presence of MC in food webs is of concern due to adverse effects on biota and exposure to humans via commercial and recreational fisheries (Paerl and Otten 2013). Little is known regarding the factors which determine MC accumulation in food webs. We hypothesized that dietary exposure would be determined in part by sources of organic matter supporting the food web. We undertook a comparative study of the James River Estuary, a sub-estuary of …

On The Challenges Of Modeling The Net Radiative Forcing Of Wetlands: Reconsidering Mitsch Et Al. 2013, Scott C. Neubauer

Biology Publications

Wetlands play a role in regulating global climate by removing carbon dioxide (CO2) from the atmosphere and sequestering it as soil carbon, and by emitting methane (CH4) and nitrous oxide (N2O) to the atmosphere. In a recent article in this journal (Mitsch et al. Landscape Ecol 28:583–597, 2013), CO2 sequestration and CH4 emissions were modeled for several freshwater wetlands that vary in vegetation type, climate, and hydrology. The authors of that study made significant errors that caused them to underestimate the importance of wetland CH4 emissions on climate dynamics. Here, I reanalyze the Mitsch et al. dataset and show that …

Regional And Scale-Specific Effects Of Land Use On Amphibian Diversity [Poster], James R. Vonesh, David Marsh, J. J. Apodaca, Karen H. Beard, Jane M. Bell, Christine Bozarth, Derrick Carper, Julie Charbonnier, Bradley J. Cosentino, Andreia Dantas, Elizabeth A. Forys, Miranda Foster, Jaquelyn General, Kristen S. Genet, Macie Hanneken, Kyle Hess, Shane Hill, Faisal Iqbal, Kara Jones, Nancy E. Karraker, Eran Kilpatrick, Tom A. Langen, James Langford, Katherine Lauer, Alison J. Mccarthy, Joseph Neale, Saumya Patel, Austin Patton, Cherie Southwick, Nathaniel Stearrett, Nick Steijn, Mohammad Tasleem, Joseph Taylor

Biology Presentations

Background/Question/Methods

Habitat loss and degradation influence amphibian distributions and are important drivers of population declines. Our previous research demonstrated that road disturbance, development and wetland area consistently influence amphibian richness across regions of the U.S. Here, we examined the relative importance of these factors in different regions and at multiple spatial scales. Understanding the scales at which habitat disturbance may be affecting amphibian distributions is important for conservation planning. Specifically, we asked: 1) Over what spatial scales do distinct landscape features affect amphibian richness? and 2) Do road types (non-rural and rural) have similar effects on amphibian richness? This is …

Non-Lethal Effects Of Dragonfly Predators On The Interactions Between The Tadpoles Of Two Neotropical Hylid Frogs [Poster], Zacharia Costa, James R. Vonesh

Biology Presentations

Background/Question/Methods

Prey frequently alter their phenotype in response to perceived predation risk in order to reduce vulnerability. Differences in the costs and benefits of such plastic responses to predators can lead to differences in non-consumptive predator effects. Such differences can occur between taxa or through ontogeny for a given species, and may alter interactions between prey and other species in the food web. Less vulnerable prey may respond less to predator cues compared to vulnerable prey and thus may have higher performance in risky environments. Here we build upon previous research on the tadpoles of two hylid treefrogs, Agalychnis callidryas …

Interactions Between Competition And Predation Shape Early Growth And Survival Of Two Neotropical Hylid Tadpoles [Poster], Sergio C. Gonzalez, Justin C. Touchon, James R. Vonesh

Biology Presentations

Background/Question/Methods

Recent literature reviews reveal that competition typically has stronger effects on growth than the presence of predators, while predation has larger effects on survival. Further, past studies show that predators typically lessen the negative effect of competition on growth and also make interspecific competition beneficial for the survival of focal species. We examine the independent and combined effects of competition and predation for survival and growth of the tadpoles of two co-occurring Neotropical hylid frogs (Agalychnis callidryas and Dendropsophus ebraccatus). Our experiment crossed tadpole species composition (single and mixed at single total density) with the presence or absence of …

Terrestrial Predators And Abiotic Conditions Affect Hatching Survival Of Arboreal Frog Eggs: Implications For Aquatic Food Web Dynamics [Poster], Jessica Hite, James R. Vonesh

Biology Presentations

Background/Question/Methods
Recent work in food web studies has highlighted the importance of terrestrial and aquatic linkages and the trait and density-mediated effects of predators and abiotic conditions. Many studies have focused on species with complex life histories (amphibians and aquatic insects) because they encompass a variety of trophic levels and form important linkages between terrestrial and aquatic food webs. For example, red-eyed treefrog, Agalychnis callidryas eggs are deposited on vegetation overhanging ponds and risk mortality from a variety of terrestrial predators and abiotic stressors. Red-eyed treefrog embryos, however, exhibit phenotypic plasticity in hatching time in response to these terrestrial stressors. …

Life-Centered Ethics And The Human Future In Space, Michael Noah Mautner

Chemistry Publications

In the future, human destiny may depend on our ethics. In particular, biotechnology and expansion in space can transform life, raising profound questions. Guidance may be found in Life-centered ethics, as biotic ethics that value the basic patterns of organic gene/protein life, and as panbiotic ethics that always seek to expand life. These life-centered principles can be based on scientific insights into the unique place of life in nature, and the biological unity of all life. Belonging to life then implies a human purpose: to safeguard and propagate life. Expansion in space will advance this purpose but will also raise …