Thesis (M.Sc.(Agric.))(Plant Production)--University of Pretoria, 2006. / Includes bibliographical references. Available on the Internet via the World Wide Web.

Thesis (M.S. in environmental science)--Washington State University, May 2007. / Includes bibliographical references (p. 30-33).

Reproductive studies in invasive plants are necessary for an understanding of their potential to establish and spread in foreign environments. Elaeagnus umbellata Thunb. (autumn olive) is an invasive woody shrub that flowers early in the spring and is often noted for its abundant fruit set. This study examined the reproductive biology of E. umbellata in Illinois, where it is highly invasive. Hand-pollination experiments were performed to determine the breeding system of E. umbellata, and floral visitors were collected to determine its pollinators. Experiments showed that E. umbellata is a predominantly outcrossing species with a self-incompatible breeding system. However, individual variation was detected in several reproductive characteristics. Pollen tube analyses revealed that a small percentage of individuals allow successful self-pollen tube growth, and self-fruit set resulting from automatic self-pollination (autogamy) was relatively high in a few plants. Automatic self-pollination is possible because the male and female parts of flowers mature sychronously, but the likelihood of autogamy may vary among individuals due to variability in the spatial separation of male and female parts (herkogamy). Variability in the incompatibility system and the level of herkogamy may impact the outcrossing rates and reproductive success of individuals. The majority of floral visitors to E. umbellata were generalist pollinators. Frequently visiting bees included small and large species such as native Andrena spp., Augochlorella aurata, Bombus spp., Ceratina calcarata, Xylocopa virginica, and the introduced Apis mellifera. Bombylius major (large bee fly) and the moth Mythimna unipuncta (armyworm) were also frequent visitors. Most of the above insect taxa are pollinators of E. umbellata based on analysis of pollen on insect bodies. E. umbellata is likely to achieve its abundant fruit set where these common pollinators and other E. umbellata are present. However, in my study sites, many individuals experienced low fruit set on branches that were open to pollinator visitation, suggesting pollen limitation may be common in some years and at certain sites. The discovery of autogamous individuals demonstrates that some E. umbellata individuals may be able to establish and spread even when mates or pollinators are limiting.

The increased movement of plants around the world is a serious and impactful environmental consequence of increased human dominance globally. Some of these plants will become established in new areas, some will proliferate, and some will become invasive causing environmental and socio-economic damage. Environmental processes contribute to plants becoming introduced, established and invasive. However, humans have an increasingly important role in all stages of the invasion process. In particular, the social processes that shape decision making, such as knowledge, risk perceptions, values and attitudes, can influence people’s behaviour that might lead to increased or decreased spread of invasive non-native plants (INNP). The social processes contributing to individual decision-making can be particularly influential in domestic gardens as it is the individual(s) responsible for that garden that decides how it is managed. Furthermore, the socio-economic impacts of INNP can be particularly acute in domestic gardens. In addition to the direct impacts of INNP in domestic gardens, an increase of their abundance therein could be detrimental to the health and well-being benefits gardens can provide, such as increased connectedness to nature. Invasion ecology is a rapidly growing area of research, however, key gaps in knowledge remain. In particular, little research has been done on INNP in domestic gardens and the perceptions of risk people have about the impacts they can have therein. This thesis applies an interdisciplinary approach to address these gaps. Japanese knotweed Fallopia japonica, is used as a case study throughout as it exemplifies many of the environmental and socio-economic impacts of INNP, many of which are particularly acute in domestic gardens. Identifying the processes contributing to the spread of INNP will help develop mitigation strategies to reduce their spread and therefore impact - this is the focus of chapters two to six. Chapter two explores the predictors of presence and abundance of Japanese knotweed at a 1km resolution within Cornwall, UK, finding that building density is the strongest predictor, followed by biophysical variables (minimum and maximum monthly temperature), and then socio-economic status of the residents within the 1km grid-cell. Chapter three considers one social process that might be contributing to the spread of INNP - the movement of propagules within soil. One of the key results of this chapter is that the abundance of invasive and naturalised species was significantly higher in garden than in housing development samples. This suggests that informal movement of soil between gardens poses a greater risk of spreading invasive plants than do commercial sources. Chapter three highlights the importance of high levels of identification skills of INNP to reduce their spread, however no previous research has tested INNP identification levels amongst the public. Chapter four explores this idea, finding that less than 20% of the public could identify Japanese knotweed. Even if people can identify INNP, if it is present in their garden they may not know how to manage it correctly and details of the impacts it can have therein. Chapter five analyses internet-based information about the management advice and impacts of INNP, determines the authors of this discourse, and considers whether and how this could be confusing to those responsible for managing domestic gardens. Analysis identified extensive variation in document structure, topics discussed, references and links to other sources, and language style; sometimes this variation was between and sometimes within author categories. A key conclusion from chapter five is that some internet-based information sources might potentially contribute to amplification (or attenuation) of risk perceptions, that could in turn lead to inappropriate management actions, resulting in increased spread of INNP. Chapter six uses a survey approach to explore risk perceptions of INNP in domestic gardens further. The results suggest differences in perceived risk of Japanese knotweed depends on people’s occupation, their direct experience of the species in a domestic context, their geographical proximity to the risk, their age and level of education. Greater understanding of the impacts INNP can have within domestic gardens will help assess the level of risk, plan mitigation strategies and design risk communication. This is the focus of chapter seven, which focuses on the economic impacts within domestic gardens. Results indicate that the magnitude and frequency of the risks Japanese knotweed poses in domestic gardens are much lower than anticipated based on media coverage, and compared with public perception. The results of this thesis have several important implications: (1) To mitigate potential inaccurate perceptions of INNP, governmental authorities need to provide clear and accurate communication about the impacts of INNP and how best to manage them. (2) When resources are limited, identifying the areas of society where knowledge is lowest or perceptions most inaccurate can help awareness and educational campaigns to be more impactful, thus reducing spread and impacts of INNP. (3) Implementation of the recommendations to reduce the spread and impacts of INNP within domestic gardens given within this thesis could contribute towards preserving the health and well-being benefits gardens can provide. Overall this thesis demonstrates further evidence of the need to consider the human causes and solutions to INNP and the need for knowledge on this topic to be applied by a diverse range of stakeholders.

Subsidized harvest of invasive silver carp Hypopthalmichthys molitrix and bighead carp H. nobilis (collectively referred to as Asian carp) from the Illinois River have been initiated in an effort to control their populations. However, market-driven control strategies have been suggested in an effort to reduce or eliminate the need for subsidies. Given that Asian carp are not a favored food fish in the U.S. and exporting to Asian markets is currently not economically feasible, industrial applications such as fish meal production have been explored. Fish meal production to support aquafeed manufacturing is potentially a high-value, high-volume market which is essential to a market-driven approach. However, the nutrient composition of Asian carp as a raw material from the Illinois River needs to be evaluated as well as the nutrient digestibility and production performance of a rendered Asian carp fish meal product to fully assess its suitability for use in aquafeeds. To determine the suitability of Asian carp to support aquafeed manufacturing, we evaluated seasonal and geographical differences in Asian carp harvested from the Illinois River, performed standard digestibility trials with hybrid striped bass and rainbow trout, and assessed production performance through standard feeding trials with hybrid striped bass, rainbow trout, and cobia. Results indicate slight geographical and seasonal variation in body composition, though both species represent protein-dense raw materials suitable for fish meal production. Additionally, Asian carp fish meal is a highly digestible feedstuff that closely resembles the nutrient content of traditional menhaden fish meal sources, although it is slightly less digestible. Production performance of fish fed practical Asian carp fish meal based diets was similar to those that used menhaden fish meal. Overall, Asian carp fish meal appears to be a highly-digestible, nutrient-dense ingredient suitable for inclusion in aquafeeds. Therefore, rendering Asian carp into fish meal appears to be a viable market-driven approach to help control Asian carp populations.

This study was conducted to provide insight into the response of Achyranthes japonica to management tools in the form of complete shoot removal (clipping) and herbicide application at Cypress Creek National Wildlife Refuge (CCNWR) in southern Illinois. Field herbicide experiments indicate that A. japonica is susceptible to foliar applications of systemic, broad leaf herbicides. The removal of A. japonica by herbicide, however, did not allow for re-establishment of the surrounding plant community in years 2011 and 2012. Seedlings at node stage 3, 4 and 6 were able to regrow following complete shoot removal indicating that this species can sustain perennial growth when it develops three nodes and that the node stage at which plants were clipped did not affect their regrowth potential. In the greenhouse, A. japonica was able to regrow following complete shoot removal at the 3 node stage and the number of branches and apical nodes on a plant are the best predictors of the regrowth potential for this species. Achyranthes japonica's susceptibility to foliar applications of systemic herbicides in the greenhouse was high. Herbicide titration results indicate that of the six herbicides tested (2,4-D ester, triclopyr, glyphosate, aminopyralid, triclopyr+fluroxypyr, and aminopyralid+metsulfuron) triclopyr required the least amount of active ingredient to reduce the growth of A. japonica by 50% (GR-50). Results overall suggest that A. japonica reaches perennial growth by the time it has three nodes, making clipping as a management tool only successful if done before plants have developed three nodes. Achyranthes japonica perennial plants are highly susceptible to foliar applications of broad leaf systemic herbicides making them a good management tool in the field.

Exotic plant species can be a serious threat to native ecosystems and the human economy. They have often been found to grow in greater abundance along roadsides, and seem to use them as corridors of invasion into the surrounding habitats. This study sought to determine whether there were any relationships between the distribution of exotic plant species and adjacency to roads in southern Illinois. To test this question, I conducted two research projects. For the first project, I ran transects from active and abandoned roadsides into adjacent forest interiors to collect data on the presence and abundance of exotic species. Along most roads, exotic species richness declined with increasing distance from the road. In most cases, abandoned roads were more likely than active roads to have a high abundance of Lonicera japonica and Rosa multiflora. For the second project, I collected geographical data for exotic species from field studies, herbaria records, and literature records, and compared them based on distance from the nearest road, family composition, and life form composition by both number of species and number of records. On average, herbaria records were farther from the road than field studies. Composition of families and variety of life forms were not significantly different when comparing by number of species, but were significantly different when comparing by number of records.

Invasive plant species have widespread effects on the ecosystems they inhabit. Extensive research has been done on the economic and ecological impact of invasive species in relation to native plant species, but little is known about the effect of these species on native fauna. My study examined the impact of an invasive plant species Elaeagnus umbellata (autumn olive) on small mammals populations in southern Illinois. Elaeagnus umbellata is a native shrub of southeast Asia and was introduced to the United States in the 1830s. It is now the fifth most abundant invasive plant species in the state of Illinois. To determine the impact of this invasive shrub on small mammal populations, Sherman traps were set up in six separate trapping webs, three in upland forests with heavy E. umbellata cover and three in upland forests with little to no E. umbellata cover (control). Trapping spanned three seasons from March-August 2013. Through the use of capture and release methods, individuals were measured, weighed, and marked for possible recapture. Beginning in season 3, Cuterebra fontinella (bot fly) abundance in small mammals was also assessed. Differences in relative abundance of small mammal populations were determined using a repeated measures ANOVA with a Tukey test. T-tests were used to determine any significant difference among small mammals between forest types. Very little difference was found among the measured variables between the invaded and control forest sites. Prevalance of C. fontinella was also similar, but the resulting percentage of infection was much higher when compared to other studies in the literature. These results indicate there is little effect of E. umbellata on small mammal populations, although the long-term impacts of this invasive species may need further research.

An effective incentivized hunting program was initiated in the United States in 2002 to reduce the population of nutria (Myocastor coypus), an invasive species of rodent contributing to wetland erosion. In this thesis, I analyze the ethics of intervening through the nutria hunting program by applying four different non-anthropocentric theories of animal and environmental ethics to the case: Peter Singer’s utilitarianism, Tom Regan’s animal rights, Paul Taylor’s respect for nature, and Aldo Leopold’s land ethic. I explain why the theories of Singer and Leopold would support intervention, while Regan’s and Taylor’s would not. Additionally, due to its unique features, the situation with the nutria is a perfect test case for evaluating the merits of these four competing theories. After taking issue with Singer’s, Regan’s, and Taylor’s theories as they pertain to the nutria case, I conclude that Leopold’s land ethic is best able to account for our considered moral belief that killing the invasive nutria in order to protect the wetlands is morally appropriate. Because Leopold’s land ethic is holistic and inegalitarian, it can explain both why the nutria are a problem and why they are less morally valuable than the native wetland species they are destroying. Of the four theories, only Leopold’s includes the entire biotic community in the sphere of moral consideration, and in so doing, recognizes that what is at stake in this case is the wetland itself, and that we have a duty to preserve its integrity, even at the cost of nutria life.

Resumo: Avaliar a prevalência de disfunções do assoalho pélvico após o tratamento de carcinoma invasor de colo uterino. Uma amostra de sessenta mulheres submetidas á histerectomia radical (n=20), radioterapia exclusiva (n=20) ou quimiorradiação (n=20) foram incluídas para análise. As funções de assoalho pélvico foram avaliadas por meio de questionários e avaliação física após, pelo menos, 6 meses do final do tratamento. A análise estatística realizada foram os testes de Mann-Whitney, kruskal-Wallis, Wilcoxon, Qui-quadrado quando apropriados. O p<0,05 foi considerado significativo. A idade variou de 28 a 75 anos (52,5 l 9,3 anos). O estádio clínico do tumor (FIGO) foi I em 25 casos (41,67%), II em 12 (20%), III em 22 (36,67%) and IV em 1 caso (1,67%). Os grupos foram semelhantes em relação a idade, paridade, menopausa e IMC. O comprimento vaginal foi menor em pacientes submetidas à radioterapia ou quimiorradiação quando comparadas com o grupo de histerectomia radical (5,5l1,9, 5,3l1,5 versus 7,4l1,1 cm, respectivamente; p<0,001). Não houve diferença em relação à incontinência urinária de esforço (p=0,56), urgência (p=0,44), urgeincontinência (p=0,54) e noctúria (p=0,53). Vida sexual ativa foi mais freqüente nas mulheres submetidas à cirurgia (90%) quando comparadas com o grupo da radioterapia (50%) e quimiorradiação (50%) (p=0,01). A dispareunia foi maior no grupo da radioterapia exclusiva, seguida da quimiorradiação e da histerectomia radical (p=0.021). O grupo da quimiorradiação apresentou maior freqüência evacuatória/dia (p<0.001) e a presença de diarréia foi menor no grupo da histerectomia radical (p=0.025), nos outros dois grupos foi semelhante. As disfunções do assoalho pélvico são comuns após o tratamento para carcinoma invasor de colo uterino. A radioterapia e a quimiorradiação são mais associadas às limitações... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study was undertaken to evaluate the prevalence of pelvic floor dysfunction following treatment for invasive carcinoma of the cervix. Sixty patients submitted to radical hysterectomy (n=20), radiotherapy (n=20) or chemoradiation (n=20) were included for analysis. Pelvic floor function was assessed by questionnaires and physical examination at least 6 months after the treatment has finished. Main outcome measures were urinary, intestinal and sexual functions and vaginal length. Data of patients were collected prospectively. Statistical analysis was performed using oe2 , Mann- Whitney, Kruskal-Wallis and Wilcoxon as appropriate. P-value< 0.05 was significantly. The age of patients ranged from 28 to 75 years old (52.5 l 9.3 years). Tumor staging (FIGO) was I in 25 cases (41.67%), II in 12 (20%), III in 22 (36.67%) and IV in 1 case (1.67%). Vaginal length was shorter in the patients submitted to radiotherapy or chemoradiation compared to radical hysterectomy group (5.5l1.9, 5.3l1.5 versus 7.4l1.1 cm; p<0.001). There were no differences regarding stress incontinence (p=0.56), urgency (p=0.44), urgeincontinence(p=0.54) and nocturia (p=0.53). Active sexual life was significantly higher in women submitted to surgical treatment (p=0.01), and dyspareunia was higher in the group of radiotherapy (p=0.021). The bowel frequency was higher in group of patients submitted to chemoradiation (p=0.025). Pelvic floor dysfunctions are common after treatment for invasive cervical carcinoma. Radiotherapy and chemoradiaiton are more associated to a limitation in sexual activity and bowel dysfunction than surgery. / Orientador: Agnaldo Lopes da Silva-Filho / Coorientador: Paulo Traiman / Banca: Jorge Nahás Neto / Banca: Sérgio Augusto Triginelli / Mestre