Life Sciences Commons^™

Critical Forces That Structure Subtidal Ecological Communities In The Gulf Of Maine, And The Integration Of Invasive Species Into These Communities, Martine C. Wagstaff

Graduate Doctoral Dissertations

Shallow subtidal epibenthic communities worldwide are under threat from exploitation, pollution, eutrophication, acidification, climate change, and invasive species, with implications for ecosystem diversity, productivity, function, and services. Subtidal ecosystems in the Gulf of Maine are particularly impacted, making it crucial to understand these habitats so that our impacts can be predicted and mitigated. I investigated the basic ecological forces that structure shallow subtidal epibenthic communities in this region, and how invasive species integrate themselves into these communities. I used community phylogenetic and functional trait analyses to investigate if invertebrate communities in the rocky subtidal are assembled via deterministic or random …

Plant Community Responses To Invasive Shrub And Vine Removal In An Urban Park Woodland., Eric Richard Moore

Electronic Theses and Dissertations

Counter to what some people think, urban areas can be biodiversity hotspots. Maintaining this biodiversity can be challenging, since exotic shrubs and vines block sunlight and threaten native plant regeneration. Since 2007, the Louisville Olmsted Parks Conservancy (LOPC) has spent $2 million on invasive plant management in Cherokee Park. Before the project began, long-term transects were established by the LOPC to collect baseline presence/absence data on 11 invasive plant species. In 2014, I revisited these transects and documented presence/absence data on the entire plant community. I found that four species (garlic mustard, winter creeper, Japanese honeysuckle, and English ivy) have …

Attraction And Risk In Urban Bird Habitats, Megan E. Litwhiler

Dissertations

Urban expansion is an increasing threat to native bird populations. Consequently, maintaining and developing safe urban habitat space is necessary for conservation. Birds living in, or migrating through, urban areas utilize a variety of managed green-spaces such as parks, gardens, college campuses, and cemeteries. In addition to managed habitats, birds may use abandoned property that has been reclaimed by vegetation and associated spontaneous, biological communities. Such urban habitats may provide valuable resources for birds and other wildlife; however, these sites often contain high densities of non-native plants and can be polluted, potentially imparting a greater risk than benefit to the …

Is Chir Pine Displacing Banj Oak In The Central Himalaya? Socioeconomic Implications For Local People And The Conservation Of Oak Forest Biodiversity, Ankush Nautiyal

Graduate Theses and Dissertations

Various studies have suggested that chir pine (Pinus roxburghii) is replacing banj oak (Quercus leucotrichophora) in the Central Himalaya. Five sites with three different types of forests (banj oak, chir pine and mixed oak-pine) were sampled to compare the diversity of their vegetation and to assess the impact of this ongoing conversion on biodiversity. Soil samples collected from oak and pine forests were analyzed and compared. In addition, dendrochronology was used to obtain age estimates of chir pine and to understand the growth response of this species to precipitation. Also, samples of ectomycorrhizal fungi were collected in the form of …

Alliaria Petiolata (M.Bieb.) Cavara & Grande [Brassicaceae], An Invasive Herb In The Southern Ozark Plateaus: A Comparison Of Species Composition And Richness, Soil Properties, And Earthworm Composition And Biomass In Invaded Versus Non-Invaded Sites, Jennifer D. Ogle

Graduate Theses and Dissertations

Invasive species are widely recognized as organisms that severely alter ecosystem processes in the habitats to which they are introduced. Alliaria petiolata is one of the most important invasive plants in forests of the northern United States. This study examined the geographic distribution of the plant in the southern Ozarks, as well as the effect that it may be having on natural processes within forests of the region by comparing plant species richness, plant cover, and soil properties in invaded and non-invaded plots. It was found that A. petiolata is not significantly altering species richness, cover, or soil properties in …

Phylogenetically Novel Species Are More Successful Due To High Competitive Ability At Local And Regional Scales, Amy C. Patterson

Senior Honors Papers / Undergraduate Theses

While few introduced exotic species become invasive, this small number of species poses serious threats to biodiversity, ecosystem function, and recreation, leading ecologists to study why certain species become invasive and why certain communities are prone to invasions. Several leading hypotheses seek to explain invasiveness, including the Enemy Release Hypothesis, the trait superiority hypothesis, and the Biotic Resistance Hypothesis, but none are consistently supported in the literature. We suggest that the lack of uniting hypothesis is a result of the inability to put multiple proposed mechanisms in the same framework, and suggest for a uniting framework Darwin’s Naturalization Hypothesis along …

A Microhabitat Assessment Of Five Species Of Invasive Plants In The Ozarks And Appalachians, Eric Hearth

Graduate Theses and Dissertations

Invasive species present a threat to native communities and their introduction and expansion can alter community structure and dynamics. Multiple approaches can be employed for invasive species management including prevention and detection. In this study, microhabitat assessments were conducted on colonies of five species of invasive plants, Alliaria petiolata (M. Bieb.) Cavara & Grande, Lespedeza cuneata (Dum. Cours.) G. Don, Lonicera japonica Thunb., Microstegium vimineum (Trin.) A. Camus, and Rosa multiflora Thunb. in the Ozark Plateau and Appalachians. Elevation, soil moisture, soil pH, light ratio, slope, aspect, distance to disturbance, as well as soil nutrient levels were recorded for each …

Relative Abundances Of The Recently Introduced Barnacles, Megabalanus Coccopoma And An Unidentified Species Of Megabalanus, In The Southeastern U.S., Jennifer L. Tyson

Honors College Theses

ABSTRACT

Megabalanus coccopoma is a prominent invasive species off the coast of Georgia. Recently, among collected samples thought to be M. coccopoma, several individuals of an unidentified species of barnacle were found. The species has been identified as a Megabalanus species, but is still unidentified to the species level. Species identification is difficult due to morphological variation, inconsistent taxonomic keys, and unknown origin. In this study I developed a method to accurately distinguish M. coccopoma from the unidentified Megabalanus sp. using sequence differences in the mitochondrial Cytochrome Oxidase I (COI) gene. This study will provide an accurate estimate of …

Phylogenetically Novel Species Are More Successful Due To High Competitive Ability At Local And Regional Scales, Amy C. Patterson

Undergraduate Research Symposium Posters

Invasive species are widely considered to be a major threat to native biodiversity, however some studies suggest that exotic species seldom cause the extinction of native species, and may even increase biodiversity at some spatial scales. This leads to the question of whether exotic plant species that have naturalized to a new range are biologically distinct from their native counterparts. Here, we chose one common native and one common exotic plant species from each of five plant families, and evaluated their growth over one growing season for two proposed mechanisms of biological invasion. We evaluated the Enemy Release Hypothesis (ERH), …

Efficacy Of Dormant Season Herbicide Application On Control Of Japanese Honeysuckle (Lonicera Japonica) For Habitat Restoration In Kentucky, Jason L. Weese

Theses and Dissertations--Forestry and Natural Resources

Kentucky’s disappearing native grassland communities provide habitat for native flora and fauna. A study was conducted to compare the efficacy of herbicides in control of the invasive Japanese honeysuckle (Lonicera japonica) applied at times when most native species are dormant. Six herbicide mixtures (glyphosate, glyphosate + imazapyr, glyphosate + imazapic, imazapyr, triclopyr + difluphenzopyr, and metsulfuron + difluphenzopyr) were applied in three seasons to assess the effect of application timing of each mixture on honeysuckle control. Herbicides were applied with a CO² pressurized sprayer at three sites in a randomized complete block design. Pretreatment sampling indicated that …

Soil Bacterial Structure And Function Associated With The Invasive Grass Microsteguim Vimineum And Two Native Grasses, Jennifer Kay Bell

Electronic Theses and Dissertations

Soil microorganisms play vital roles in biogeochemical cycles and are necessary for maintaining soil health. An invasive plant that alters the structure and function of the soil microbial assemblage could gain an advantage over native plants, enhancing its ability to invade new habitats, alter ecosystem function, and hinder efforts to reestablish native populations. Assays of enzyme activity and next generation sequencing of bacterial 16S rRNA genes were used to assess the soil microbial function and community structure associated with the invasive grass, Microstegium vimineum and two co-occurring native grasses (Dichanthelium boscii and Chasmanthium laxum). Significantly lower enzyme activity was found …

Zebra Mussel (Dreissena Polymorpha) Habitat Associations In Four West-Central Minnesota Lakes, April Rose Londo

All Graduate Theses, Dissertations, and Other Capstone Projects

In 1989, zebra mussels (Dreissena polymorpha) were first documented in the land of ten thousand lakes in the Lake Superior Basin at Duluth. Zebra mussels are successful invaders because the species attaches to substrates with byssal threads, can adapt to a wide range of environmental conditions, and has a free-swimming veligers that are easily transported. Although invasive mollusks pose a range of economic and ecological threats to inland waters, our understanding of zebra mussels in Minnesota lakes remains limited. To gain additional information regarding zebra mussel ecology in lake systems, I conducted research in four west-central Minnesota lakes that were …

Landowner Knowledge And Opinions Of Invasive Species And Their Management Surrounding A Suburban Nature Preserve, Christina Mclaughlin

Legacy Theses & Dissertations (2009 - 2024)

Invasive species are a growing human-caused threat to biodiversity around the globe as they are moved both accidentally and intentionally through trade routes. The human component of conservation management is especially critical in invasive species, as human awareness is key to preventing and rapidly responding to new introductions. Yet the social component of management is poorly studied, even as outreach efforts continue to grow in an effort to gain public support. This study attempts to understand public knowledge and opinions toward invasive species and their management through an online survey of neighboring landowners to a suburban nature preserve, the Albany …

Ecology Of Feral Cats Felis Catus And Their Prey In Relation To Shrubland Fire Regimes, Tim S. Doherty

Theses: Doctorates and Masters

Invasive predators are major drivers of global biodiversity loss and their impacts may be worsened by other disturbances such as fire. I examined how the fire history of shrublands influences the ecology of feral cats Felis catus, dingoes Canis dingo and their prey species in Western Australia’s northern Wheatbelt region.

A review of the literature revealed that feral cats inhabit a diverse range of ecosystems worldwide, but are generally recorded most often in habitat types characterised by a mixture of plant growth forms close to ground level. Cat habitat use is influenced by predation/competition, prey availability, shelter availability and …