Master of Science (MS), Wright State University, 2017, Biological Sciences

Invasion of Alliaria petiolata has negative direct and indirect impacts on the systems in which they invade. This study focuses on further identifying impacts which this non-native A. petiolata has on herbivores whose range they have invaded. Oviposition on A. petiolata by the specialist butterfly, Pieris virginiensis, is known to be a mismatch event leading to larval death from sinigrin and alliarinoside. To observe if the related specialist, Anthocharis midea, falls into the same oviposition sink paired plot comparisons between native Cardamine concatenata and non-native A. petiolata were conducted. Early in the season paired-plot comparisons showed a preference for native C. concatenata while later comparisons a preference for A. petiolata. A significant influence of the date of oviposition on selected host was seen. Environmental stressors such as drought and disease can lead to changes in plant development and productivity. Trade-offs exists between defenses so as one area of defense is invested in other areas of defense will not be allocated resources because of the energetic costs. Under these environmental stressors resources should be shifted away from herbivory defense and with the reduction of secondary metabolites herbivores will be expected to perform better. Environmental stressors including drought and disease on larval performance and preference were investigated. Influences of drought stress on non-native A. petiolata were not sufficient enough to allow for specialist herbivores A. midea and P. virginiensis to reach pupation. Generalist herbivore Trichoplusia ni, the cabbage looper, was short lived and unable to reach pupation on any A. petiolata, normally watered or drought stressed. Anthocharis midea preference assays show a clear preference for native C. concatenata over non-native A. petiolata, severely drought stressed C. concatenata over normally watered plants and no preference between drought stressed or normally watered A. petiolata. Presen (open full item for complete abstract)

Committee: Donald Cipollini Ph.D. (Advisor); Thomas Rooney Ph.D. (Committee Member); John Stireman III Ph.D. (Committee Member) Subjects: Biology; Ecology

Doctor of Philosophy (PhD), Wright State University, 2015, Environmental Sciences PhD

Humans have caused drastic changes in ecosystems and communities through their modification of the natural landscape. Rare species, often highly specialized, are more impacted by these changes. Pieris virginiensis is a rare butterfly native to eastern North America that is a species of concern due to negative influences from habitat loss and plant invasion. This thesis discusses several threats to P. virginiensis, including habitat loss, climate change, competition, and the cascading effects of a novel European invasive plant, Alliaria petiolata, that attracts oviposition but does not allow for larval survival. First, I examined a local extinction event and attributed it primarily to several seasons of poor weather and extreme climatic events, but with contributions by an increasing deer population and the introduction of A. petiolata. Second, I found that A. petiolata attracts approximately two-thirds of total eggs, but no larvae survive on the novel host. I tested several chemical causes of larval death and identified two potential contributors: sinigrin, which delays growth, and alliarinoside, which reduces survival. I also examined competition between P. virginiensis, its host plants, and novel competitors in the habitats. First, I looked at shared habitat use between P. virginiensis and another, exotic Pierid butterfly P. rapae. Although habitats are occasionally shared, P. rapae is most likely not a large influence on the success or failure of P. virginiensis. Second, I examined the influence of A. petiolata when it competes with two native host plants of P. virginiensis, and found differential effects of each life stage of A. petiolata on the native host plants. Finally, I used a combination of species distribution modeling and genetic sequencing to determine the current and future states of P. virginiensis given the changing climate and other stressors on P. virginiensis populations. Although secure currently, future stressors will most likely cause (open full item for complete abstract)

Committee: Don Cipollini Ph.D. (Advisor); John Stireman Ph.D. (Committee Member); Jeffrey Peters Ph.D. (Committee Member); Thaddeus Tarpey Ph.D. (Committee Member); Francie Chew Ph.D. (Committee Member) Subjects: Biology; Botany; Climate Change; Conservation; Ecology; Environmental Science; Environmental Studies

Master of Science (MS), Ohio University, 2015, Plant Biology (Arts and Sciences)

Since the loss of Castanea dentata (American chestnut) from eastern hardwood forests, invasive species have occupied many of the forests where chestnut once resided. Even though agencies have begun to replant hybrid chestnuts into the forests, no one has examined how invasive species might interact with American chestnut. In this study, allelopathic impacts on chestnut were mimicked by adding aqueous extracts or biomass of three allelopathic invasive species tree of heaven (Ailanthus altissima (Mill.) Swingle), garlic mustard (Alliaria petiolata (M.Bieb.) Cavara and Grande), and Amur honeysuckle (Lonicera maackii ( Rupr. ) Maxim.)) to soils supporting chestnut seedlings. In greenhouse experiments, chestnut seeds were treated weekly with aqueous extracts of biomass from the invasives. Chestnut seedlings were also planted in gardens and treated with root or shoot biomass from the invasives. Finally, chestnut seedlings were planted in a forest at sites with garlic mustard present and at sites where garlic mustard had been regularly removed for 8 yrs. Growth factors of chestnut, such as height, mass, and basal area, were measured. Chestnut seedlings treated with tree of heaven extracts had lower heights and more re-sprouts than the control groups. However, results were not consistent among the experiments. Chestnut seedlings treated with some invasive plant biomass, including tree of heaven biomass, had heights statistically similar to the control groups. When treated with roots of garlic mustard, chestnut heights were statistically lower than the negative control. Chestnut seedlings planted in garlic mustard plots in the forest were only statistically taller the first time they were measured, but were not statistically different thereafter. The results from these initial experiments suggest that the allelopathic effects from tree of heaven may negatively impact reintroduction of American chestnut; however, other invasives may be less problematic.

Committee: Brian McCarthy Dr. (Advisor); Jared Deforest Dr. (Committee Member); David Rosenthal Dr. (Committee Chair) Subjects: Ecology; Plant Biology

Master of Science (MS), Wright State University, 2012, Biological Sciences

Our goal was to characterize the interactive feedback between garlic mustard (Alliaria petiolata) and European earthworm species in southwest Ohio. Earthworm community composition, abundance and biomass were compared between 0.1 m2 plots of garlic mustard, cut-leaved toothwort (Cardamine concatenate), wild ginger (Asarum canadense), or no plant cover. Exotic earthworms were present in the study site. Earthworm abundance and biomass did not correlate with garlic mustard percent cover. There was a greater density of earthworms in the fall than in the spring. Worm abundance differed between garlic mustard and wild ginger plots and cut-leaved toothwort and control plots, suggesting that earthworms may prefer to be located under plants that produce high biomass. Worm biomass did not differ between the plants. There was a greater abundance of endogeic worms below all plants, while anecic worms contributed the most biomass. Our results do not support strong feedback between garlic mustard and European earthworms.

Committee: Thomas Rooney PhD (Advisor); James Runkle PhD (Committee Member); Don Cipollini PhD (Committee Member) Subjects: Biology; Ecology

Master of Science, University of Toledo, 2009, Biology (Ecology)

Recent studies have shown that exotic plant species can have wide-ranging effects on soil ecosystem processes and biotic diversity, and those effects may be more extensive than previously thought. Garlic mustard [Allliaria petiolata (M. Bieb.) Cavara and Grande] is an exotic, invasive herb that poses a threat to North American forests by reducing native plant performance and recruitment. However, little is known about potential impacts to belowground communities and processes. The object of this study was to determine the effects of A. petiolata on soil physical, chemical, biogeochemical, and biotic properties. Soil samples were collected between October 2006 and February 2008 from plots with A. petiolata present or absent in three Ohio forests: the University of Toledo Stranahan Arboretum (Arboretum), Fuller Preserve (Fuller), and South Park (South). Variables measured included moisture content, pH, organic matter (SOM), nutrient dynamics [dissolved organic carbon (DOC), microbial biomass carbon (Cmic), dissolved organic nitrogen (DON), microbial biomass nitrogen (Nmic), ammonium, nitrate, and phosphate], microbial community function [activities of acid phosphatase (PHOS), α-glucosidase (AG), β-glucosidase (BG), N-acetyl-β-glucosaminidase (NAG), β-D-cellobiohydrase (CBH), β-xylosidase (BXYL), leucine amino peptidase (LAP), urease, phenol oxidase (phenox), and peroxidase (perox)], and microbial community structure [community DNA profiles, Simpson index (D), Shannon index (H'), and richness (S)]. Results showed that A. petiolata presence had a significant affect on only approximately one third of the measured variables. Generally, the variables affected and the direction of effects (positive or negative) were inconsistent both spatially and temporally. Soil moisture, SOM, Nmic, DOC, phosphate, BG activity, ratio of C- to P-acquiring enzyme activities (C:P), and bacterial richness and diversity were lower with A. petiolata present at Arboretum, but most treatment diff (open full item for complete abstract)

Committee: Daryl Moorhead PhD (Advisor); Michael Weintraub PhD (Advisor); William Von Sigler PhD (Committee Member) Subjects: Biology; Ecology; Environmental Science

Doctor of Philosophy, The Ohio State University, 2005, Horticulture and Crop Science

Studies were conducted at the plant, population, and community level to address questions concerning (1) seed germination in Alliaria petiolata (2) weed community composition and structure in response to tillage, rotation and herbicide, and (3) variation in Abutilon theophrasti. Alliaria petiolata seeds are dormant at maturity, requiring approximately 90 to 105 days cold-moist stratification at 4 to 5 °C for germination to occur. Mechanically scarified, and H2O2 and H2SO4 treated seeds germinated within 35 days when GA3 was applied exogenously. The composition of the weed-seedbank community was characterized 35 years after the implementation of a long-term study involving cropping sequence (continuous corn, corn-soybean, corn-oat-hay) and tillage system (conventional-, minimum-, and no-tillage). Values of S, J, and H' recorded for all combinations of the three-crop sequence were typically greater than the values of S, J, and H' reported for either the one and two-crop rotations. As the intensity of soil disturbance decreased, values for S increased. Mean germinable weed seed density was greatest in the no-tillage treatments across rotations and years. Results suggest that the weed seed community in a corn-oat-hay rotational system differs in structure and composition from communities associated with continuous corn and corn-soybean systems. There is concern that the widespread use of genetically-modified glyphosate-tolerant crops (GTCs) will alter agricultural weed community dynamics with respect to glyphosate-tolerance and emergence phenology. Species associated with individual tillage and rotation treatments were not different from species recorded in the same plots prior to the exclusive use of GTCs and glyphosate, suggesting that significant changes in weed community composition and structure have not occurred. Abutilon theophrasti is a noxious weed in modern row-crop agriculture. This study characterized the morphological, phonological, and genetic variation ve (open full item for complete abstract)

Committee: John Cardina (Advisor) Subjects: Agriculture, Agronomy

Master of Science (MS), Ohio University, 2012, Environmental and Plant Biology (Arts and Sciences)

Disturbance such as forest management is thought to promote invasive species spread. This study uses population demography to address the spread of the invasive species Ailanthus altissima, Alliaria petiolata, and Microstegium vimineum in forested sites in southeast Ohio. Invasive species populations were examined in the silvicultural treatments prescribed burn and timber harvest, plus control plots with no management. Seed rain, seedling establishment, and the soil seed bank was studied for each population. All invasive seeds formed a persistent seed bank and experienced seasonal dormancy, but the proportion of dormant seeds varied among species (p<0.05). Slope aspect effected seed survivorship and dormancy (p<0.05) for each species. Dormancy for each species showed no relationship or a weak relationship with time since seed burial. Invasive populations expanded at a constant rate among treatments, and invasive seeds changed dormancy conditions seasonally to allow for germination during favorable conditions, which may contribute to invasive ability.

Committee: Glenn Matlack PhD (Advisor); Stefan Gleissberg PhD (Committee Member); Harvey Ballard PhD (Committee Member) Subjects: Botany

Master of Science, Miami University, 2008, Botany

Exotic plant invasion may result in the disruption of symbioses between plants and soil biota, potentially affecting plant fitness and community composition. I tested whether the invasive biennial Alliaria petiolata (garlic mustard) affects abundance and community composition of ectomycorrhizal fungi (EMF) associated with experimentally planted Quercus rubra (northern red oak) seedlings. Proportional EMF colonization, EMF species richness and diversity, and Q. rubra survival were lower for seedlings in a stand with high density A. petiolata than in a stand without A. petiolata. Community composition of EMF also differed between stands. A comparison of naturally occurring Q. rubra seedlings in a moderate vs. a low density site showed a trend toward less EMF with more A. petiolata, while richness and diversity did not differ. Though confounded by uncontrolled environmental variables, these results are consistent with A. petiolata negatively impacting ectomycorrhizal fungi, warranting more research on this indirect effect on native plants.

Committee: David Gorchov (Advisor); Nicholas Money (Committee Member); Charles Kwit (Committee Member) Subjects: Botany; Ecology

Master of Science, Miami University, 2006, Botany

The impact of invasive plant species on native plants is largely assumed to be negative, but supporting evidence is sparse. We examined the long-term effects of herbicide on Alliaria petiolata and the subsequent effects on the plant community in southwestern Ohio. November herbicide application effectively killed A. petiolata, but did not reduce recruitment; spring densities of A. petiolata rosettes were not lower in sprayed plots. Only modest differences were noted in forest floor vegetation, suggesting A. petiolata rosettes competed with other plant species. We tested the hypothesis that higher June precipitation promotes rosette growth and survival with a rain shelter experiment. The three different water treatments affected soil moisture, but not A. petiolata growth or survival. Dry treatments may not have replicated drought years based on water availability measurements. June precipitation is probably not a reliable predictor of A. petiolata rosette survival in years with above average precipitation.

Committee: David Gorchov (Advisor) Subjects:

Master of Science, Miami University, 2005, Botany

The biennial Alliaria petiolata (M. Bieb) Cavara and Grande is an invasive herb currently impacting broadleaf forests in the eastern United States. To test the effects of herbicide on A. petiolata , investigate other factors affecting its density, and examine its competitive impact on the native community, I monitored 50 1 x 1 m plots in two forest stands in Hueston Woods State Nature Preserve, Preble and Butler Cos., OH. Herbicide treatment affected A. petiolata density intermittently over a three-year span, showing the strongest effect after the third year. Bare ground did not affect A. petiolata density among plots, but June precipitation was positively correlated with density across years. In the second-growth stand, spring perennials and graminoids increased in response to A. petiolata reduction in the third year. Herbicide should be applied in the dormant season of years with high summer rainfall to ensure significant reduction of the A. petiolata population.

Committee: David Gorchov (Advisor) Subjects:

Master of Science (MS), Wright State University, 2012, Biological Sciences

Garlic mustard (Alliaria petiolata) has been previously found to be significantly affected negatively by powdery mildew (Erysiphe cruciferarum). While we could not significantly corroborate those findings we did find evidence that E. cruciferarum does inhibit A. petiolata's allelopathic and competitive effects which benefits some target neighbor species such as Impatiens capensis and Elymus canadensis. We also found that the inhibition of A. petiolata by E. cruciferarum had negative consequences on another neighboring invasive species (Lonicera maackii) compared to those grown next to uninfected A. petiolata. Acer saccharum, a slow-growing species had no effect between neighbors. Sterilization treatments had variable effects on target plants, many of which mirror the effects which allelopathic plants (A. petiolata) that disrupt soil microbes seem to have. Sterilization inhibited growth of E. canadensis through the destruction of beneficial effects from microbes, while increasing the growth of L. maackii by inhibiting the pathogenic effects of microbes.

Committee: Don Cipollini Ph.D. (Advisor); James Amon Ph.D. (Committee Member); Thomas Rooney Ph.D. (Committee Member) Subjects: Biology; Botany; Conservation; Ecology; Environmental Management; Forestry; Plant Biology; Plant Pathology; Plant Propagation; Plant Sciences; Wildlife Conservation