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.

Thesis (M.S.)--Indiana University, 2008. / Title from screen (viewed on April 23, 2008). Department of Earth Sciences, Indiana University-Purdue University Indianapolis (IUPUI). Advisor(s): Gabriel M. Filippelli, Catherine J. Souch, Gary D. Rosenberg. Includes vitae. Includes bibliographical references (leaves 85-87).

Thesis (MS)--Montana State University--Bozeman, 2009. / Typescript. Chairperson, Graduate Committee: Andrew J. Hansen. Includes bibliographical references.

Rural villages are important elements in cultural landscape. Thanks his variety here often enact biocentres and make possible to existence wide spectrum of plant, that could occur in other places and by other conditions only rock hard. At present however happens under the thumb of wasteful management to typical provincial nature suppression and to extinction of some species. This work was bent on vegetation investigation in three villages in Volyňsko in district Strakonice. Ascertained kinds spectrum distinguish on the basis of many factors, for example location position, abiotic factors or way of management. To other subject of interest was derived, let us say invasive kinds occurrence as well as protected species. On the basis these results can tell, that the rural villages are in monotonous agricultural landscape significant biotope that it is necessary to protect.

Diss. (sammanfattning) Umeå : Umeå universitet, 2006. / Härtill 4 uppsatser.

Depuis des décennies, les dépôts atmosphériques azotés sont connus pour agir de manière sévère sur le fonctionnement des écosystèmes forestiers. Ils influent en effet la biogéochimie du sol, l’équilibre des éléments nutritifs et, en conséquence, la croissance des espèces végétales, la biodiversité végétale de sous-étage et plus globalement la santé des forêts. Dans le cadre de la convention internationale de Genève visant à limiter la pollution atmosphérique transfrontalière à longue distance, le concept de « Charges Critiques », défini à la fin des années 1980, a été retenu comme outil permettant d’évaluer la sensibilité d’un écosystème aux contaminants. Il permet d’estimer la quantité maximale de polluants atmosphériques acceptable par l’écosystème avant apparition de conséquences néfastes à son fonctionnement. De plus, en raison de l’impact des changements globaux sur les processus biogéochimiques régissant le fonctionnement des écosystèmes, l’influence des dépôts atmosphériques et du changement climatique doit être considéré de manière simultanée pour évaluer l’évolution de l’état des écosystèmes au cours du temps. Dès lors l’enjeu majeur est de pouvoir prédire l’effet combiné de ces facteurs sur les écosystèmes forestiers français. C’est l’objectif de ce travail de thèse. Des modèles dynamiques couplés biogéochimiques – écologiques, tels que les modèles ForSAFE-VEG ou PROPS, ou écologiques (basés sur la base de données EcoPlant) ont été développés ou adaptés à ces fins, et appliqués à différentes échelles locale, régionale et nationale, selon différents scénarios de dépôts et climatiques. L’application et la calibration du modèle couplé ForSAFE-VEG sur des placettes forestières permanentes du réseau RENECOFOR ont permis de prédire l’évolution de la composition biogéochimique de la solution du sol et en cascade de la composition floristique de trois sites, sous différents scénarios de dépôts atmosphériques et de changement climatique. Les principales évolutions des sites sont liées à leurs caractéristiques stationnelles. Si le changement climatique joue un rôle prédominant sur la réponse des espèces, les écosystèmes oligotrophes restent sensibles aux dépôts de N. A court terme, l’effet combiné des dépôts et du changement climatique sur le long terme est modulé par les effets de la gestion forestière. L’extrapolation du modèle couplé à plus large échelle nécessite une continuité dans la disponibilité des données d’entrée et de calibration de la réponse des espèces. Les données et scénarios de changement climatiques ont été complétés et actualisés à l’aide du modèle SAFRAN et des nouveaux scénarios RCP régionalisés. La calibration de la réponse des espèces végétales à l’échelle de la France a été réalisée à partir des mesures de la base de données phytoécologiques EcoPlant, par le développement de modèles de distribution d’espèces (SDM), en intégrant simultanément des variables climatiques, édaphiques, d’énergie et de nutrition. Le couplage entre le modèle ForSAFE et les SDM assure une modélisation robuste à l’échelle du territoire de la réponse des écosystèmes forestiers dans le temps, calibrée pour les conditions pédoclimatiques françaises. La modélisation des charges critiques d’acidité, d’eutrophisation et de biodiversité sur l’ensemble des sites RENECOFOR et la totalité des écosystèmes forestiers français montre des sensibilités variées aux dépôts de soufre et d’azote en fonction des écosystèmes, avec parmi les plus sensibles les Landes, la Sologne et le Massif Central. Des indices de qualité des habitats (HSi) ont été calculés à l’échelle de tous les écosystèmes par le modèle PROPS et les SDM. La sélection des espèces représentatives reste primordiale car elle conditionne la valeur finale de HSi. Ce paramètre est l’un des plus sensibles à prendre en compte dans la modélisation. Il est à mettre en relation avec les objectifs de protection des écosystèmes voulus par les gestionnaires. / For decades, it has been known that atmospheric nitrogen depositions have a severe impact on the operations of forest ecosystems. Indeed, they affect the soil biogeochemistry, the balance of the nutritive elements and consequently the plant species growth, the biodiversity of the understory vegetation and more globally the forest health. As part of the Geneva Agreement to limit the long-range transboundary air pollution, the concept of "critical loads", defined towards the end of the 1980s, was adopted as a tool to enable the assessment of the sensitivity of the ecosystems to contaminants. It can be used to estimate the maximal amount of atmospheric contaminants which can be accepted by the ecosystem before significant harmful effects on specified sensitive biological indicators appear. In addition, because of the impact of global warming on biogeochemical processes regulating the functioning of ecosystems, the influence of atmospheric depositions and climate change must be considered simultaneously to evaluate the evolution of ecosystem conditions over time. Since then, the major issue has been to be able to predict the combined effect of these factors on the French forest ecosystems. This is the aim of this PhD work. Coupled dynamic biochemical-ecological models, such as ForSAFE-VEG or PROPS models, or ecological (based on EcoPlant database) were developed or adapted for this purpose and applied to different local, regional and national scales against different deposition and climatic scenarios. The application and calibration of the coupled model ForSAFE-VEG on permanent forest plots from the RENECOFOR network enabled prediction of the evolution of the soil solution biogeochemical composition, as well as monitoring of the floristic composition of three sites, under different scenarios of atmospheric deposition and climate change. The principal site evolutions are related to their stational characteristics. If the climate change plays a primary role on a species’ response, the oligotrophic ecosystems remain sensitive to nitrogen depositions. On a short term basis, the combined effect of the deposits and long term climate change is modulated by forest management. The extrapolation of the coupled model on a larger scale requires continuity in the availability of input data and calibration of the species’ response. The data and climate changes scenarios were completed and updated with the SAFRAN model and new regionalised RCP scenarios. The calibration of the response of plant species throughout France was carried out using measurements of the phytoecological database EcoPlant, via development of species distribution models (SDM). The coupling between ForSAFE and the SDM ensures a robust global modelling of the forest ecosystems’ response over time, calibrated for the French pedoclimatic conditions. The modelling of the acidic, eutrophication and biodiversity critical loads, on all the RENECOFOR sites and French forest ecosystems, shows the various sensitivities to sulphur and nitrogen depositions depending on the ecosystem. Ecosystems located in the Landes, Sologne and Massif Central appear to be amongst the most sensitive ones. The Habitats Suitability Index (HSI) was calculated throughout all the ecosystems via PROPS models and the SDM. The selection of representative species remains pivotal as the final HSI value is conditional, depending on this factor. This parameter is one of the most sensitive factors to take into account with the model. It must be linked with forest managers' objectives for the protection of the ecosystems.