The Environmental Science and Design Symposium, formerly the Land and Water Symposium, is a multidisciplinary forum that promotes the exchange of ideas related to the resiliency of natural and built systems. This year’s theme, Complexity of Environmental Legacies, reflects the challenges of developing sustainable systems in landscapes transformed by decades of modification and contamination. Speakers from a wide range of disciplines (fashion, geology, geography, architecture, and ecology) will address topics related to urban, sustainability, restoration, and the integration of design with biological systems.
Browse the Environmental Science and Design Research Initiative 2019 Collections
« Previous | 37 - 42 of 56 | Next »
Oak tree differentiation of defense and reallocation strategies in response to herbivore pressure
03/21/2019Plant strategies against herbivory may involve defending themselves by producing plant secondary metabolites (PSM), regrowing to negate injuries from tissue loss (tolerance), or reallocating resources to better defend or protect themselves from further damage. We investigated the strategies of oak plants to minimize herbivory by investment in tannins and reallocation of non-structural carbohydrates. Oak species may differentially invest in defenses and reallocation depending on the intensity and location of herbivore feeding. We simulated the effects of herbivory by removing 25% or 75% of oak tissue, removing either the apical or lateral meristems. The investment in defenses may act as a selective pressure driving herbivore diversity and behavior. Using 12 oak species from different parts of a well-supported phylogeny, we applied five treatments of simulated herbivory, varying in intensity and location. The 12 species were chosen to represent a broad array of geographical and phylogenetic diversity. Using an untransformed statistical analysis, we found that oak species invest differentially in defensive mechanisms. We will also present a more thorough phylogenetic comparative analysis of the data to determine if differences in defense and reallocation strategies are a result of adaptation to herbivory or if defense and reallocation strategies are associated with particular oak lineages.Predicting Lake Erie Algal Blooms based on Alternate Ecosystem States Theory: Early Warning Signals of an Impending Bloom
03/21/2019Algal blooms have become a yearly occurrence in Lake Erie for some time now. These blooms are not only a nuisance but can also pose a risk to human health. Theoretically, early warning signals will exist prior to a shift in ecosystem state, i.e. an algal bloom. Indicators, such as increasing variance and rising autocorrelation close to 1, have been associated with transitions to alternate ecosystem states. These early warning signals have been observed in some whole-ecosystem experiments using quickest detection (QD) methods. The goal of this study was to determine if these early warning signals were detected in chlorophyll data prior to an algal bloom in a real-life ecosystem, Lake Erie. The QD method for detecting early warning signals associated with shifts in ecosystem states was used. In Lake Erie, the shift from a mixed phytoplankton state to a cyanobacterial dominated state was considered a transition to an alternate ecosystem state. Results showed that increasing variance before an algal bloom was not always detected, and therefore early warning signals of an impending algal bloom were not seen. The research suggests that examining phycocyanin, a pigment specific to blue-green algae, may provide more promising results in the future. If successful, this research could be used to provide warnings of impeding algal blooms to water treatment managers, allowing them to be prepared for the situation.Pyrite Morphology, Texture, and Trace Metals Across a Weathering Profile (from Parent Rock to Soil) of Ohio Coal Shales
03/21/2019Acid mine drainage (AMD) refers to the acidic outflow of water from a mining site caused by the weathering of pyrite (FeS2) present in coal. Oxidation of pyrite, within underground mine work and surface waste, releases sulfuric acid and metals, including nickel, cobalt, arsenic, and lead into surface and subsurface waters. AMD negatively impacts water quality, wildlife, and human health. The aim of this study was to determine changes in pyrite particle size, morphology, texture, and composition during the weathering of the parent coal-shale rock. This was accomplished by collecting scanning electron microscopy (SEM) images and energy dispersive spectroscopy (EDS) element maps of pyrite in the following materials: (1) the parent coal-shale rock; (2) rock powder before and after simulated weathering; and (3) soils developing on historic mine waste. Shale samples were crushed to 63, 250, and 2000 µm and subjected to an artificial weathering process over several months to observe if particle size impacted the degree of weathering and its effect on mineral morphology. Soils were collected at various depths and prepared as thin sections. The commonest morphologies seen were framboids and octahedra. Oxidation rim and replacement textures were observed repeatedly, especially in the soils. Iron and sulfur oxide concentrations were universally observed over the range of crushed particle sizes and various surface topographies. Oxidation rim textures are most abundant on small particles consistent with prolonged weathering, resulting in greater degrees of oxidation. Preliminary results suggest AMD production increases with greater variability of surface topography and decreasing particle size. Understanding how the release of AMD will progress in an impacted system, controlled by the degree of weathering of parent rock, is important to assessing its environmental impact. Characterization of mine spoil is instrumental to proper planning and implementation of treatment systems.Quantifying the rate of denitrification in different stream components of a 4th order stream
03/21/2019Nitrogen is an important macroelement essential for life. Denitrification is an important step in the nitrogen cycle which microbially converts nitrate to nitrous oxide (incomplete denitrification) or di-nitrogen gas (complete denitrification). Denitrification is ecologically significant in streams as it can help in mitigating the amount of nitrate transport downstream. In this study, conducted in summer 2018, we examined the rate of denitrification in various stream components (sediment, water and macroinvertebrates). Freshwater macroinvertebrate guts have been shown to be a site for denitrification in prior research works. For the purpose of the study two sites in the West Branch of the Mahoning River (in Jennings Woods) were chosen. Macro-invertebrates that were sampled include crayfish, mayfly, caddisfly and members of Athericidae. Rate of denitrification was measured with and without acetylene block treatment. Each component (sample) was replicated thrice per treatment except caddisfly and mayfly samples due to lack of sufficient individuals that could be obtained from the respective sites. Caddisfly and mayfly samples were used only for the study with acetylene block treatment. Rate of denitrification was statistically significant among samples in both the sites and between the two different treatments. Sample, site, interaction between sample and site and the interaction between sample, site and treatment were also statistically significant. The future goal is to study the functional genes associated with denitrification in the various stream components and perform 16S gene sequencing to gain insight regarding the microbial community present in the various stream components.Remote Sensing of Cyanobacterial and Harmful Algal Blooms in Lake Okeechobee and Biscayne Bay, Florida
03/21/2019Cyanobacterial and Harmful Algal Blooms (CyanoHABs) have become a major topic of concern for homeowners and environmental groups in Florida, with blooms occurring in both Lake Okeechobee and Biscayne Bay in prior years. While Biscayne Bay and Lake Okeechobee are distinct water bodies, with different manifestations of the blooms, in both environments CyanoHABs can contain toxins that are harmful to humans and animals, can lead to fish and wildlife kills, as well as disrupt ecosystems. Furthermore, recreational and economic use of the waters of Biscayne Bay and Lake Okeechobee are negatively impacted by these blooms. Monitoring and assessment of the CyanoHABs in both water bodies is a vital aspect of understanding the drivers and impacts of CyanoHAB growth in Florida. Spectral decomposition of satellite remote sensing images of Lake Erie has been shown to be effective at discriminating between in-water constituents, both those related to CyanoHABs, and those that are non-HAB forming. Here we show that the KSU spectral decomposition method is also successful in identifying in-water constituents in Florida waters using images from the Sentinel 3A- Ocean and Land Color Instrument, acquired on 16 July 2017 and 28 July 2018. We identify the CyanoHAB signal in Lake Okeechobee on both days, as well as the sediment and algal signal in Biscayne Bay.
Road Salt Runoff in Freshwater Constructed Wetlands: A Year in the Life
03/21/2019Road salts, brines, and other de-icers are used to melt snow and ice on roads and sidewalks. The runoff resulting from this process is high in salt ions such as sodium, chloride, calcium, magnesium, and potassium. These ions end up in our waterways, and contribute to the problem of increasing salinity in freshwater ecosystems. In this study, two constructed freshwater wetlands near Kent State University were monitored for one year by measuring conductivity with in situ conductivity probes, concentration of road salt ions in surface water samples, and salt content in plant tissue. This data set allowed us to assess seasonal trends in road salt runoff as well as to estimate a mass balance for road salt ions in these systems. We found that the wetlands were a considerable sink for road salt ions over the course of the year. Moreover, the degree to which each wetland retained the ions was not the same. The wetland with continuous flow and comparatively less pore space retained less of the ions than the intermittently flowing, deeper wetland. This notable imbalance in the salt budget of these wetlands, despite their differences in flow regime, is symptomatic of unsustainable road salt practices in these and similar watersheds. Should this pattern continue, there could reach a point where the wetlands could no longer store the influx of salt ions each year, resulting in a large release of saline water into downstream freshwater ecosystems. Long term studies like this are critical to addressing these issues, and these findings can be used to inform management decisions not only in Kent, Ohio, but also in any city to better balance ecosystem function with public safety.