Biology Commons^™

Ecosystem Response To Increasing Hurricane Disturbance: Comparing Nutrient Cycling Dynamics Associated With Early- And Late-Successional Tree Species In A Wet Tropical Forest, Miriam Kleit

Biology Honors Projects

Puerto Rico has seen changes in the frequency and severity of disturbances in recent years as hurricanes become more frequent and more intense under climate change. In ecosystems experiencing increasing disturbances, we expect that species composition will shift as early successional trees become more common. These changes to species composition and community ecology are likely to affect terrestrial nutrient cycling both directly and indirectly, and it is still not well understood how shifting community composition may alter ecosystem functioning. To address this gap, I measured carbon (C) and nitrogen (N) variables in soils, microbial biomass, roots, leaves, and soil greenhouse …

Interior Least Terns (Sternula Antillarum Athalassos) In A Landscape Of Fear: Explaining Predator Frequency On Sandbars Using Habitat Features, Carice N. Kimbrell

ATU Theses and Dissertations 2021 - Present

Causes of colony failure in interior least terns (Sternula antillarum athalassos) have been a prevalent topic for researchers investigating this previously endangered species. In Arkansas, these colonies are primarily located on sandbars formed along the McClellan-Kerr Arkansas River Navigation System. Reduction in nesting site quality may put this sensitive species at a greater risk for predator encounters. In my first chapter, I identified which sandbar characteristics resulted in higher frequencies of predator encounters at interior least tern colonies. In my second chapter, I investigated how those predators influenced colony production and whether interior least tern colonies exhibited similar …

Could Biological Soil Crusts Act As Natural Fire Fuel Breaks In The Sagebrush Steppe?, Lea A. Condon, Douglas J. Shinneman, Roger Rosentreter, Peter S. Coates

Biology Faculty Publications and Presentations

For decades, large portions of the semi-arid sagebrush ecosystem have been experiencing increased frequency and extent of wildfire, even though small, infrequent fire is a natural disturbance in this ecosystem (Baker, 2006). Increased wildfire is threatening the existence of sagebrush ecosystems and the wildlife species that depend upon them (Baker, 2006; Coates et al., 2016). Increased wildfire in sagebrush ecosystems is often driven by invasive annual grasses, especially cheatgrass, Bromus tectorum (L.). Invasion can initiate a trajectory toward a “grass-fire cycle”, in which cheatgrass increases fine fuel loadings that promote fire, and native plant species do not recover quickly after …

Fire History And Long-Term Carbon Accumulation In Hemi-Boreal Peatlands Companion Dataset, Dominic Uhelski, Evan Kane, Katherine Heckman, Rodney Chimner

Michigan Tech Research Data

This dataset contains peat property data including location, depth, bulk density, organic matter content, and carbon content, infrared spectra, and radiocarbon dates. Peat cores were collected between 2011 and 2019. Analyses were performed between 2018 and 2021. Samples were collected from peatlands in Michigan, Wisconsin, and Minnesota for the purposes of reconstruction of fire history. The data is associated with a yet-to-be-published manuscript to be submitted to Ecosystems.

A README file is included describing the contents of the dataset and all major spreadsheet files contain a Meta worksheet which describes each column of
data.

Fire And Periodical Cicadas: Impacts On Soil Nutrients And Understory Plant Germination, Andrea Gamache

Master of Science in Integrative Biology Theses

Purpose

A compound disturbance, composed of a prescribed fire and a periodical cicada emergence, occurred in northern Georgia in the summer of 2021. Independently these disturbances have substantial effects on the surrounding ecosystems. This study investigated the collective impact on soil composition and seed germination.

Methods

Through the soil analysis of cicada turrets, burned soil, and unburned soil, we hope to understand the composition of each soil type. Additionally, a 2 x 2 factorial study was performed with those same samples, providing insight into the impact on seed germination these disturbances have. The two factors were between burned and unburned …

A Natural Experiment Identifies An Impending Ecological Trap For A Neotropical Amphibian In Response To Extreme Weather Events, Morgan A. Clark, William M. Ota, Sierra J. Smith, Brett K. Muramoto, Summer Ngo, Gabriella E. Chan, Maxwell A. Kenyon, Matthew C. Sturtevant, Max G. Diamond, Gary M. Bucciarelli, Lee B. Kats

All Faculty Open Access Publications

Extreme weather events are predicted to increase as a result of climate change, yet amphibian responses to extreme disturbance events remain understudied, especially in the Neotropics. Recently, an unprecedented windstorm within a protected Costa Rican rainforest opened large light gaps in sites where we have studied behavioral responses of diurnal strawberry poison frogs (Oophaga pumilio) to ultraviolet radiation for nearly two decades. Previous studies demonstrate that O. pumilio selects and defends perches where ultraviolet radiation (UV-B) is relatively low, likely because of the lethal and sublethal effects of UV-B. In this natural experiment, we quantified disturbance to O. pumilio habitat, …

Dataset For: Mapping Fire History And Quantifying Burned Area Through 35 Years Of Prescribed Fire History At An Illinois Tallgrass Prairie Restoration Site Using Gis, Erin G. Rowland-Schaefer, Elizabeth M. Bach, Bill P. Kleiman, Holly P. Jones

Research Datasets

Fire was important to pre-colonization prairies. In today’s remnant and reconstructed prairies, managers frequently employ prescribed fire, a historical management practice that limits woody encroachment, suppresses non-native species, and promotes nutrient cycling. However, few long-term prescribed fire spatial datasets are available for study. We used archived images of prescribed fire maps and hand-drawn fire records to generate a geospatial record of the prescribed fire history at Nachusa Grasslands, a combination remnant and restored preserve in northern Illinois. This record contains maps of the prescribed fire history of the preserve across the entirety of its 35-year history. We used the maps …

Coupled Structure-Function Responses To Disturbance: High Structural Complexity Resistance Supports Primary Production Resistance, Kerstin M. Niedermaier

Theses and Dissertations

The capacity of forests to resist structural change and retain material legacies–the biotic and abiotic resources that persist through disturbance–is crucial to sustaining ecosystem functioning after disturbance. However, the role of forest structure as both a material legacy and feature supporting carbon (C) cycling stability following disturbance has not been widely investigated. We used a large-scale disturbance manipulation to ask whether LiDAR-derived canopy structures as material legacies drive 3-year responses of NPP to a range of disturbance severity levels. As part of the Forest Resilience Threshold Experiment (FoRTE) in northern Michigan, USA we simulated phloem-disrupting disturbances at a range of …

Grassland Bird Responses To Bison And Prescribed Fire Disturbances At Nachusa Grasslands And Kankakee Sands, Antonio Del Valle

Graduate Research Theses & Dissertations

Grazing from native herbivores such as bison (Bison bison), in combination with prescribed fire, are applied to tallgrass prairies by managers to recreate important disturbance patterns in this ecosystem. Bird communities may be indirectly impacted by these disturbances through their direct impact on plants that provides critical breeding habitat for grassland birds. The objectives of this research are to determine the impacts that bison and prescribed fire have on grassland breeding birds in two tallgrass prairie preserves, Kankakee Sands and Nachusa Grasslands. Birds, vegetation structure, and bison activity were surveyed systematically at these two preserves in 2020 and 2021. Prescribed …

Periodically Disturbing The Spatial Structure Of Biofilms Can Affect The Production Of An Essential Virulence Factor In Pseudomonas Aeruginosa, Rebecca J. Quinn, Ivana Barraza, Laura García-Diéguez, Camryn Pajon, Lauren E. Krausfeldt, Kerollos Ibrahim, Laura A. Enzinna, Morgan E. Thorn, Omar Tonsi Eldakar, Travis J. A. Craddock, Robert P. Smith

Biology Faculty Articles

Understanding the environmental factors that affect the production of virulence factors has major implications in evolution and medicine. While spatial structure is important in virulence factor production, observations of this relationship have occurred in undisturbed or continuously disturbed environments. However, natural environments are subject to periodic fluctuations, including changes in physical forces, which could alter the spatial structure of bacterial populations and impact virulence factor production. Using Pseudomonas aeruginosa PA14, we periodically applied a physical force to biofilms and examined production of pyoverdine. Intermediate frequencies of disturbance reduced the amount of pyoverdine produced compared to undisturbed or frequently disturbed conditions. …

Intense Mowing Management Suppresses Invader, But Shifts Competitive Resistance By A Native To Facilitation, David U. Nagy, Emily Rauschert, Ragan M. Callaway, Tamas Henn, Rita Filep, Robert W. Pal

Biological, Geological, and Environmental Faculty Publications

Interactions among native and invasive species may affect management outcomes and goals. We implemented different mowing regimes to control the invasive Solidago gigantea and restore natural diversity, and also examined interactions between Solidago and a European native competitor, Tanacetum vulgare in the context of these regimes. Experimentally planted Tanacetum suppressed Solidago by 79% without management, and a suite of mowing management regimes reduced the density of Solidago by 80–98% when Tanacetum was absent. But, when Tanacetum was added, the density of the invader was not reduced by mowing. Put another way, in mowed plots with Tanacetum, Solidago was twofold to …

The Impacts Of Disturbance On Submerged Aquatic Macrophytes Populations Of The Jemez Mountains, New Mexico, Virginia F. Thompson

Biology ETDs

This dissertation investigates the effects of disturbance (a catastrophic forest fire and decadal-level multi-day flood) on populations of submerged aquatic macrophytes (SAMs) in the streams and rivers of the Jemez Mountains of northern New Mexico, USA. Research conducted and reported in this dissertation addresses the following research questions: 1.) What factors influence the presence or absence of SAMs in Jemez Mountain streams? 2.) How does disturbance (catastrophic wildfire and decadal-level flood) change the amount of aboveground SAM biomass? and 3.) How does that disturbance change the nutrient content (%C, %N, %P) and nutrient stoichiometry of SAMs? These disturbance events had …

Increasing The Frequency Of Periodic Spatial Disturbance Decreases Surface Attachment Protein Expression In Staphylococcus Aureus, Ivana M. Barraza

All HCAS Student Capstones, Theses, and Dissertations

Staphylococcus aureus is an opportunistic pathogen that can cause a variety of acute and chronic illnesses. The severity of these illnesses such as sepsis, necrotizing pneumonia, and toxic shock syndrome is measured through the virulence that S. aureus inflicts on its host. Methicillin-resistant S. aureus (MRSA) is commonly associated with secondary infections and is challenging to treat given the limited selection of antibiotics that are effective against it. Accordingly, novel approaches to reduce S. aureus pathogenicity are required. S. aureus regulates pathogenesis through a cell-to-cell communication system referred to as quorum sensing. Effective communication determines the production of two broad …

Disturbance, Defense And Fitness In Silverleaf Nightshade (Solanum Elaeagnifolium) In Their Native Range In South Texas, Jesus Chavana

Theses and Dissertations

The role of human disturbance in accelerating weed growth is well understood. While most of these studies have focused on soil mediated disturbance, mowing is also a management practice that could impact weed traits. Using silver leaf nightshade (Solanum elaeagnifolium), a noxious and invasive weed, we asked whether continuous mowing affects growth and plant defense traits. We found that mowed plants produced significantly less fruits, had lower total seed fitness, but had higher seed mass, and germinated significantly faster. When three common herbivores were allowed to feed on the seedlings; tobacco hornworm (Manduca sexta), a generalist Solanaceae caterpillar gained more …

Herb-Layer Dynamics In An Old-Growth Forest: Vegetation–Environment Relationships And Response To Invasion-Related Perturbations, Taylor M. Buskey, Margaret E. Maloney, Julia I. Chapman, Ryan W. Mcewan

Biology Faculty Publications

Temperate forests of eastern North America are subject to multiple invasions from non-native species that have the potential to drive long-term dynamics in biodiversity. Garlic mustard (Alliaria petiolata (M. Bieb.) Cavara and Grande) is an invasive plant in many deciduous forests, and management efforts often focus on removing this species to initiate native species restoration. Agrilus planipennis Fairmaire (emerald ash borer; Coleoptera: Buprestidae) is a non-native insect pest that has caused substantial loss of ash trees (Fraxinus spp. L.) in North America. Our goal was to understand how the herbaceous layer in an old-growth forest responded to the removal of …

Disruption Of Pyoverdine Synthesis In Pseudomonas Aeruginosa Through Periodic Disturbance Of Biofilm Structure, Rebecca J. Quinn

All HCAS Student Capstones, Theses, and Dissertations

Infections due to bacteria were once easily treated using antibiotics. However, the effective shelf life of antibiotics is diminishing due to the rise and spread of antibiotic resistant bacteria. Accordingly, novel approaches to treating infections are required. Pseudomonas aeruginosa is a multi-drug resistant, biofilm forming opportunistic pathogen. A determinant of P. aeruginosa’s pathogenicity is pyoverdine, a siderophore that is used to sequester iron from the environment. After being produced by a bacterium, pyoverdine is secreted into the environment where it complexes with iron. The pyoverdine-iron complex is then returned to the bacteria through diffusion, where it drives the synthesis of …

Synergies Among Environmental Science Research And Monitoring Networks: A Research Agenda, J. A. Jones, P. M. Groffman, J. Blair, F. W. Davis, H. Dugan, E. E. Euskirchen, S. D. Frey, T. K. Harms, E. Hinckley, M. Kosmala, S. Loberg, S. Malone, Sydne Record, A. V. Rocha, B. L. Ruddell, E. H. Stanley, C. Sturtevant, A. Thorpe, T. White., W. R. Wieder, L. Zhai, K. Zhu

Biology Faculty Research and Scholarship

Many research and monitoring networks in recent decades have provided publicly available data documenting environmental and ecological change, but little is known about the status of efforts to synthesize this information across networks. We convened a working group to assess ongoing and potential cross-network synthesis research and outline opportunities and challenges for the future, focusing on the US-based research network (the US Long-Term Ecological Research network, LTER) and monitoring network (the National Ecological Observatory Network, NEON). LTER-NEON cross-network research synergies arise from the potentials for LTER measurements, experiments, models, and observational studies to provide context and mechanisms for interpreting NEON …

The Effects Of Prescribed Burning And Microhabitat Type On Ant (Formicidae) Functional Groups And A Survey Of Ants In The Dr. Howard Reynolds Nature Area (A Mixed Grass Prairie), Ashley N. Durr

Master's Theses

This project sought to understand how prescribed burning and microhabitat type impacts Kansas ant functional groups and also whether prescribed burning in different microhabitat types altered the burn’s impact on those functional groups. The Dr. Howard Reynolds Nature Trail, located in Hays, Kansas, was burned in the spring of 2019. The area consists of 2 distinct habitat types: a dry, mixed-grass dominated uphill area and a moist, densely vegetated downhill area. Pitfall trapping was conducted during the summers of the year prior to the burn (2018) and the year following the burn (2019). 15 pitfall traps were spread across each …

Biogeochemical Recuperation Of Lowland Tropical Forest During Succession, Benjamin W. Sullivan, Rachel L. Nifong, Megan K. Nasto, Silvia Alvarez-Clare, Camie M. Dencker, Fiona M. Soper, Kevin T. Shoemaker, F. Yoko Ishida, Joana Zaragoza-Castells, Eric A. Davidson, Cory C. Cleveland

Biology Faculty Publications

High rates of land conversion and land use change have vastly increased the proportion of secondary forest in the lowland tropics relative to mature forest. As secondary forests recover following abandonment, nitrogen (N) and phosphorus (P) must be present in sufficient quantities to sustain high rates of net primary production and to replenish the nutrients lost during land use prior to secondary forest establishment. Biogeochemical theory and results from individual studies suggest that N can recuperate during secondary forest recovery, especially relative to P. Here, we synthesized 23 metrics of N and P in soil and plants from 45 secondary …

Mechanisms Underlying Production Stability In Temperate Deciduous Forests, Shea B. Wales

Theses and Dissertations

A persistent and reliable future terrestrial carbon (C) sink will depend on how stable forest production is under more variable climate conditions. We examined how age, forest structure, and disturbance history relate to the interannual variability of above-ground wood net primary production (NPPw). Our site in northern Michigan spans two experimental forest chronosequences and three late successional stands; the chronosequences have distinct disturbance histories, originating following either clear cut harvesting (“Cut Only”) or clear cut harvesting and fire (“Cut and Burn”), and range from 21 to 108 years old. Annual NPPw was estimated using dendrochronology and site specific allometric equations. …

Dispersal In Host–Parasitoid Interactions: Crop Colonization By Pests And Specialist Enemies, Edward W. Evans

Biology Faculty Publications

Interactions of insect pests and their natural enemies increasingly are being considered from a metapopulation perspective, with focus on movements of individuals among habitat patches (e.g., individual crop fields). Biological control may be undercut in short-lived crops as natural enemies lag behind the pests in colonizing newly created habitat. This hypothesis was tested by assessing parasitism of cereal leaf beetle (Oulema melanopus) and alfalfa weevil (Hypera postica) larvae at varying distances along transects into newly planted fields of small grains and alfalfa in northern Utah. The rate of parasitism of cereal leaf beetles and alfalfa weevils …

The Successful Exploitation Of Urban Environments By The Golden Silk Spider, Nephila Clavipes (Araneae, Nephilidae), Jake Ripp, Omar T. Eldakar, Andrew C. Gallup, Paul T. Arena

Biology Faculty Articles

Urbanization typically leads to habitat destruction producing negative effects for native species, but some species may exploit these settings. This concept was investigated in the golden silk spider (Nephila clavipes), a large, formidable spider that commonly inhabits forest edges as well as open spaces in urban environments throughout its vast geographic range. Here, we compared variation of N. clavipes success as measured by body size, web size and web positioning along an urban–rural gradient in southern Florida. From morphological measurements collected in the field, urban spiders had 60% longer legs and 35% longer bodies than both park and …

Long-Term Propagule Pressure Overwhelms Early Community Determination Of Invader Success In A Serpentine Grassland, Amanda N. Carr

WWU Graduate School Collection

The role of plant diversity in reducing invasions has generated decades of debate. Diverse communities might be more resistant to invasion because the communities contain resident species that are functionally similar to the invader (limiting similarity/sampling effect), or the residents use the range of available resources more effectively (complementarity) than single species. However, the resistance of diverse communities to invasion appears to decline with increasing spatial and temporal scale, in a phenomenon called the “invasion paradox.” I addressed two groups of hypotheses related to this paradox, broadly that: (1) functional diversity and functional identity resist invasion initially, via complementarity or …

A Metadata Reporting Framework (Frames) For Synthesis Of Ecohydrological Observations, Danielle S. Christianson, Charuleka Varadharajan, Bradley O. Christoffersen, Matteo Detto, Boris Faybishenko, Bruno O. Gimenez, Val Hendrix, Kolby J. Jardine, Robinson Negron-Juarez, Gilberto Z. Pastorello

Biology Faculty Publications and Presentations

Metadata describe the ancillary information needed for data preservation and independent interpretation, comparison across heterogeneous datasets, and quality assessment and quality control (QA/QC). Environmental observations are vastly diverse in type and structure, can be taken across a wide range of spatiotemporal scales in a variety of measurement settings and approaches, and saved in multiple formats. Thus, well-organized, consistent metadata are required to produce usable data products from diverse environmental observations collected across field sites. However, existing metadata reporting protocols do not support the complex data synthesis and model-data integration needs of interdisciplinary earth system research. We developed a metadata reporting …

Effects Of Lightning On Trees: A Predictive Model Based On In Situ Electrical Resistivity, Evan M. Gora, Phillip M. Bitzer, Jeffrey C. Burchfield, Stefan A. Schnitzer, Stephen P. Yanoviak

Biological Sciences Faculty Research and Publications

The effects of lightning on trees range from catastrophic death to the absence of observable damage. Such differences may be predictable among tree species, and more generally among plant life history strategies and growth forms. We used field‐collected electrical resistivity data in temperate and tropical forests to model how the distribution of power from a lightning discharge varies with tree size and identity, and with the presence of lianas. Estimated heating density (heat generated per volume of tree tissue) and maximum power (maximum rate of heating) from a standardized lightning discharge differed 300% among tree species. Tree size and morphology …

Effects Of Wave Action On The Structure Of Fish Assemblages Across An Exposure Gradient, Lauren Liddon

Master's Theses

Disturbance affects the function and diversity of ecosystems. Increased wave exposure to salt marsh can disturb sediments and cause a loss of habitat. The purpose of this study was to explore the effects of increased wave exposure on diversity, abundance, and functional ecology of estuarine fishes. If increased wave exposure is acting as a disturbance to these habitats, ecological theory (Intermediate Disturbance Hypothesis) predicts that diversity will peak at intermediate frequencies and intensities of disturbance. Fish were sampled from 10 sites monthly for 6 years. The sites were assigned to different exposure categories (Open, Intermediate, and Sheltered) using an exposure …

Vegetation Community Changes In Two National Forests In The Pineywoods, East Texas, Trisha L. Williams

Electronic Theses and Dissertations

Despite extensive research into forest succession, little research has been directed to long-term studies. The fundamental properties of succession remain unclear and further research into terrestrial vegetation and an accounting of drivers in specific ecosystem types is required. This study addresses change in plant communities from five ecosystem types in two east Texas National Forests over a 20-year period. An analysis of 30 sample stands yields results due to various ecosystem drivers of vegetation change and uncovers plant community responses in multiple ecosystem types over this period. This research provided three key results: 1) that vegetation composition change occurs more …

Toward An Improved Conceptual Understanding Of North American Tree Species Distributions, Paige E. Copenhaver-Parry

Faculty Publications - Department of Biological & Molecular Science

Species distributions have often been assumed to represent climatic limitations, yet recent evidence has challenged these assumptions and emphasized the potential importance of biotic interactions, dispersal limitation, and disturbance. Despite significant investigation into these factors, an integrated understanding of where and when they may be important is lacking. Here, we review evidence for the factors underlying the historical and contemporary distributions of North American tree species and argue that a cohesive conceptual framework must be informed by an understanding of species ecological and evolutionary history. We further demonstrate that available evidence offers little indication of a significant, independent influence of …

Beyond Bivariate Correlations: Three-Block Partial Least Squares Illustrated With Vegetation, Soil, And Topography, Daehyun Kim, Thomas J. Dewitt, César S. B. Costa, John A. Kupfer, Ryan W. Mcewan, J. Anthony Stallins

Ryan McEwan

Ecologists, particularly those engaged in biogeomorphic studies, often seek to connect data from three or more domains. Using three-block partial least squares regression, we present a procedure to quantify and define bi-variance and tri-variance of data blocks related to plant communities, their soil parameters, and topography. Bi-variance indicates the total amount of covariation between these three domains taken in pairs, whereas tri-variance refers to the common variance shared by all domains. We characterized relationships among three domains (plant communities, soil properties, topography) for a salt marsh, four coastal dunes, and two temperate forests spanning several regions in the world. We …

Gammaridean Amphipods As Bioindicators In Subtropical Seagrass Ecosystems, Jennifer L. Sweatman

FIU Electronic Theses and Dissertations

Anthropogenic disturbances are ubiquitous in coastal marine ecosystems. As such, more intensive monitoring efforts are necessary to conserve these valuable habitats. Bioindicators, organisms that predictably respond to changes in environmental variables, may be utilized in monitoring efforts to assess ecosystem functioning. To incorporate organisms into monitoring programs as bioindicators managers need to first understand the difference between the natural phenology of the focal organisms and their responses to different forms of anthropogenic disturbance.

To determine if gammaridean amphipods could be used as indicators of changes in environmental quality in sub-tropical seagrass ecosystems, I conducted spatial and temporal surveys of amphipod …