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Direct And Indirect Effects Of Invasive Cirsium Arvense On Pollination In Southern Appalachian Floral Communities, Jesse Daniels

Electronic Theses and Dissertations

Invasive plants can alter pollination dynamics in invaded communities by disrupting patterns of pollinator visitation, pollen transfer dynamics (conspecific [CP] and heterospecific [HP]), and reproductive success. The direction of invasive effects (competitive, neutral, and facilitative) may be partially determined by spatial scale and species’ floral traits. Here, we investigated pollinator visitation, CP and HP receipt, and pollen tube growth for species in a C. arvense present community and non-present community at two scales. At the community-level, the effect of C. arvense on pollinator visitation varied among species. Floral symmetry seemed to explain this variation. At the floral neighborhood-level, we found …

Indirect Food Web Interactions: Sea Otter Predation Linked To Invasion Success In A Marine Fouling Community, Maggie F. Jenkins

Master's Theses

Humans have caused grave ecological and economic damage worldwide through the introduction of invasive species. Understanding the factors that influence community susceptibility to invasion are important for controlling further spread of invasive species. Predators have been found to provide biotic resistance to invasion in both terrestrial and marine systems. However, predators can also have the opposite effect, and facilitate invasion. Therefore, recovery or expansion of native predators could facilitate the spread of invasive species. Needles et al. (2015) demonstrated that the threatened southern sea otter (Enhydra lutris nereis) facilitated the invasion of an exotic bryozoan, Watersipora subatra. …

Genetic Structure Of Invasive Baby’S Breath (Gypsophila Paniculata) Populations In A Michigan Dune System, Hailee B. Leimbach-Maus

Masters Theses

Invasive species can reduce biodiversity of a system by outcompeting native species for resources, changing the physical characteristics of a habitat, and altering natural disturbance regimes. Coastal sand dune ecosystems are dynamic with elevated levels of disturbance, and as such they are highly susceptible to plant invasions. The topography, geographic distribution of preferred habitat, and disturbance regime in an ecosystem can influence where an invasive plant becomes established, its dispersal patterns, and how densely it grows. One such invasion that is of major concern to the Great Lakes dune systems is baby’s breath (Gypsophila paniculata). The invasion of …

Remote Sensing For Management Of Invasive Plants In Great Lakes Coastal Wetlands, Matthew James Unitis

Boise State University Theses and Dissertations

Great Lakes coastal wetlands are some of the most crucial ecosystems to biodiversity in the Great Lakes Basin, yet suffer increasing degradation due to invasive plants. Wetland plant invasions can be controlled in their initial stages, but early detection of invasive plants using field surveys are often untenable due to budget constraints. Remote sensing techniques offer solutions to management objectives during the early stages of invasion on a landscape scale due to their ability to cheaply create spatially explicit information about plant distributions. Some invasive plants, such as Typha x. glauca, are conspicuous on a large scale, and can be …

Characterization Of Urban Wetland Vegetation And Management Practices, Megan Anne Larson

Graduate Dissertations and Theses

Urban wetlands are important ecosystems that moderate flooding risks and improve water quality. Vegetation is a key component of urban wetlands; plants promote sedimentation, play critical roles in biogeochemical cycling, and provide food and habitats for other organisms. My research focuses on the standing vegetation and seed banks of urban wetland plant communities. Urban wetlands in south-central New York had a higher percent cover of invasive species in the standing vegetation and significantly lower species richness; however, native species were also common in urban flora. These sites had a high percentage of obligate wetland species, and most closely resembled emergent …

Can An Invasive Species Burn Soil Carbon? Black Locust Invasion And Soil Carbon In The Albany Pine Bush, Jacqueline Sharry

Honors Theses

Invasive plant species can have dramatic and pervasive impacts on ecosystems, from species interactions, to resource availability, to biodiversity. One such invasive plant, the nitrogen-fixing black locust tree (Robinia pseudoacacia), has had significant effects on the soil chemistry in the globally rare inland pine barren ecosystem of the Albany Pine Bush. We have documented a loss of soil carbon following invasion by black locust, one that persists long after locusts are removed. We hypothesize that the nitrogen added through fixation by the black locust increases the carbon flux from soil to the atmosphere. Because decomposition rates are dependent …

Direct And Indirect Controls On Bee Community Composition, Caroline Marie Devan

Dissertations

Bees are important pollinators, critical for the continued survival of plants in both natural and agricultural ecosystems. Diverse bee communities have been shown to increase richness in plant communities and plant reproduction depends upon bee community richness. Yet there is growing concern that pollinators, especially bees, are declining globally. This dissertation focuses on evaluating the mechanisms responsible for bee community composition in order to promote bee conservation in natural systems and their restoration in human-dominated urban and agricultural landscapes.

Bee populations are impacted directly by three things: floral resources, nesting resources and risk, primarily from natural enemies. Bees are indirectly …

The Impact Of Copper On Non-Indigenous And Native Species Of Suspension-Feeding Bivalves In Mission Bay, San Diego, California, Brian Juhl

Theses

Native (Chione californiensis) and non-indigenous bivalve species [Musculista senhousia (now known as Arcuatula senhousia), and Venerupis philippinarum] were collected from Mission Bay, San Diego, California and exposed to copper contaminated water at estimated concentrations of 0 ppb, 25 ppb, and 50 ppb over the course of two experimental periods of 18 days and 12 days. Bivalves were placed in tanks in a temperature controlled environment, and measurements of a number of parameters were taken during and after the exposure to copper: survivorship, feeding rates, growth, mucus production, and tissue copper concentrations for the entire body, …

Mitigating Bioiversity Loss Of Native Plants, Jamie Ana Grigonis

Student Theses 2015-Present

Growing up harvesting from my own vegetable garden and going from nursery to nursery with my mother, it has been extremely evident that plant biodiversity is more than just privet along driveways and carnations in window boxes. Plant biodiversity is often overlooked but crucial to having a healthy and thriving environment. Without certain plants, our ecosystems will crumble and this needs to be addressed now while it’s still at a level we can grow from. In my internship I am working alongside the director of the Thain Family Forest at the New York Botanical Gardens in order to get a …

Flames And Frogs – The Impact Of Environmental Disturbances On Host-Parasite Dynamics, Nicole Ortega

USF Tampa Graduate Theses and Dissertations

The successful completion of this work is dedicated first to my grandparents for having always shown their unwavering love and encouragement in my journeys (most of which they kindly and politely only pretended to understand) and for having also served as life-long role models who upheld an unparalleled work ethic. To many whom I consider to be my chosen family, especially Ann Williams and Brittany Sears, who kept me laughing, but more importantly, kept my crazy train from derailing during these tumultuous years. To Wayne Price and Tom Jackman, who fostered the success of my career and are the epitome …

Tracking A Tree-Killer: Improving Detection And Characterizing Species Distribution Of Phytophthora Cinnamomi In Appalachian Forests, Kenton L. Sena

Theses and Dissertations--Plant and Soil Sciences

Phytophthora cinnamomi is a soil-borne oomycete pathogen causing root rot in susceptible host species. P. cinnamomi is thought to have originated in Southeast Asia, but has since been introduced to many regions around the world, where it causes dramatic declines in many forest tree species. In the eastern US, the primary susceptible tree species of concern are American chestnut (Castanea dentata), white oak (Quercus alba), and shortleaf pine (Pinus echinata). American chestnut, functionally eliminated in the early 1900s by the rapidly acting chestnut blight (Cryphonectria parasitica), has been the subject of decades-long …