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Les espèces exotiques envahissantes végétales sont des plantes introduites et naturalisées hors de leur aire de répartition native et capables de maintenir et d’accroitre leur population. Certaines sont considérées comme transformatrices de par leur effet sur les écosystèmes : leur structure, leur fonctionnement ainsi que leur communauté végétale et animale. Ces transformations peuvent rendre certaines de ces espèces nuisibles de par leurs impacts écologiques et économiques important. Les travaux réalisés dans le cadre de cette thèse et présentés ici ont pour objectif d’approfondir les connaissances sur l’impact des invasions biologiques. La faune du sol, la végétation native et leur substrat ainsi que son fonctionnement ont été étudiés à différentes échelles spatiales. Deux espèces exotiques, envahissantes en Europe, ont été considérées comme modèles pour ces travaux : le robinier faux-acacia (Robinia pseudoacacia) et la renouée du japon (Reynoutria japonica). Premièrement, une méta-analyse globale a permis de démontrer l’effet positif des invasions biologiques végétales sur l’abondance de certains groupes de la faune du sol, notamment les consommateurs primaires, en fonction de la structure de l’habitat (ouvert ou fermé). Ensuite, une étude à large échelle sur le robinier faux-acacia a permis d’illustrer les différences qui peuvent exister dans la réponse des écosystèmes forestiers aux invasions le long d’un gradient latitudinal. Ce gradient, composé de quatre régions distinctes en Europe de l’Ouest présente des différences de climat et de végétation dominante, ces différences modifiant l’impact du robinier faux-acacia. Une étude approfondie sur le robinier faux-acacia en Normandie a permis de mieux comprendre l’effet du robinier faux-acacia sur les communautés animales et végétales ainsi que sur le fonctionnement des écosystèmes par comparaison avec deux essences natives dominantes. Finalement, une manipulation expérimentale en laboratoire a démontré l’impact des composés allélopathiques de la renouée du Japon sur une partie de la faune du sol. Cette étude a montré que certaines espèces exotiques envahissantes sont susceptibles d’influencer la faune, et les réseaux trophiques, du sol par leur métabolisme secondaire. Ces travaux illustrent l’intérêt, dans le contexte des invasions biologiques végétales, de l’étude simultanée des compartiments aériens et souterrains à différentes échelles spatiales. / Invasive alien plants are species introduced and naturalized outside of their native distribution range and which have the capacity to maintain and expand their population. Some of these species are considered to be ecosystem transformers by altering their structure, functioning as well as resident animal and plant communities. These induced alterations make some of these species undesirable through their ecological and economical impacts. The work presented in this thesis aimed at a better understanding of the impact of biological invasions by alien plants. The soil fauna, native vegetation and their substrate, as well as ecosystem functioning, were studied at different spatial scales. Two exotic alien species, invasive in Europe, were considered as biological models for this work: the black locust (Robinia pseudoacacia) and the Japanese knotweed (Reynoutria japonica). Firstly, a global meta-analysis demonstrated the positive impact that plant invasions can exert on the abundance of some groups within the soil fauna, notably primary consumers, within different types of habitats (open or closed). Then, a large-scale study on the black locust revealed the differences that can can occur in the response of forest ecosystems to invasions along a latitudinal gradient. Study sites along this gradient, distributed amog four distinct regions in western Europe, exhibit differences in climate and dominant native vegetation which can alter the impact of the black locust. A detailed study on black locust impact in Normandy demonstrated the impact of R. pseudoacacia on native plant and soil fauna communities, as well as some ecosystem functions, in comparison to two native tree species. Finally, a laboraty experiment demonstrated the impact that allelopathic compounds extracted from Japanese knotweed rhizomes can have on some organisms within the soil fauna. This study showed that some invasive alient plants can influence the soil fauna, and soil food webs, through their secondary metabolism. This thesis illustrates that simultaneous study of both aboveground and belowground ecosystem compartments at different spatial scales is of interest in the context of biological invasions.

The main aim of this dissertation is to determine the global occurence of geografically non-indigenous plant species - Giant Hogweed (Heracleum mantegazzianum), Himalayan balsam (Impatiens glandulifera), Japanese knotweed (Reynoutria japonika), Sakhalin knotweed (Reynoutria sachalinensis) and Reynoutria x bohemika in selected locations of the South Bohemian region, for example in district of Český Krumlov and České Budějovice. The theoretical part is focused on the characteristics of selected localities where there is an occurrence of these plants and description of the above-mentioned invasive plant species and thier subsequent liquidation. The result of the dissertation (of the work) are the map´s outputs processed in the Geographic Information System, which record the global occurance of geografically non-indigenous plant species.

Fallopiajaponica (Houtt.) Ronse Decraene (Japanese knotweed), an introduced, invasive, rhizomatous perennial plant, has become an increasing problem for nature conservation and land management in both rural and urban areas in the British Isles. In the native range of the plant, Japan, Taiwan and northern China, a number of varieties are recorded. Three congeners of F. japonica are present in the British Isles, F. sachalinensis, F. japonica var. conipacta and F. baldschuanica in addition to a hybrid F. x bohemica. An investigation by postal survey of the distribution of the hybrid F. x bohemica has identified 131 records for the British Isles. Both male and female plants of F. x bohemica have been recorded. Current understanding suggests that only female plants of F. japonica are present in the British Isles, inferring that the only means of reproduction is through vegetative regeneration. High rates of regeneration were recorded in this study for stem and rhizome material for both F. japonica and F. x bohemica in an aquatic and terrestrial environment. Implications of vegetative regeneration are discussed in terms of current management practices and future methods of control. A combination of digging with a mechanical excavator followed by spraying with the herbicide glyphosate decreased the time required to achieve an effective level of control of F. japonica compared to spraying alone. Fragmentation of the rhizome system through digging resulted in an increase in stem density allowing a more effective delivery of herbicide. Implications in terms of costs for F. japonica treatment on sites awaiting re-development are discussed. Analysis of data collated from surveys of F. japonica in Swansea using a Geographical Information System suggest that the primary habitats infested are waste ground and stream and river banks. Results suggest that disturbance, both by natural means and by human intervention has been the primary cause of spread of F. japonica in the British Isles. Management strategies are proposed which take account of these results and measures are put forward to help prevent future infestations.

Parkslide är en främmande invasiv växt som ohämmat sprider sig på bekostnad av närliggande vegetation och den biologiska mångfalden. Genom att undersöka möjligheten att ta vara på Parkslides egenskaper och skapa någonting användbart för vårt samhälle, utan negativ påverkan på människa, djur och framtid, så kan det i sin tur skapa en möjlighet för en hållbar utveckling. Ett annat sätt att se på befintligt råmaterial, som en del i en cirkulär ekonomi. Rapporten diskuterar resurs och värde med intention att minska användandet av nya material och byta ut dessa till mer hållbara lösningar.Genom faktainsamling och en materialdriven designprocess utforskas Parkslide som material, vilket resulterar i materialprover som öppnar upp möjligheterna för framtida marknader. / Japanese knotweed is an Invasive Alien plant that is widely spread, at the expense of nearby vegetation, which has a negative impact on the biodiversity. By examining the possibilities to use Japanese Knotweed and its characteristics, as something valuable and useful, it can result in opportunities for a sustainable development in the society. We can change the way we view the plant and possibly make it a part of a circular economy. This work will discuss resource and value with the intention to reduce the use of new materials and switch those to a more sustainable solution.Through literature studies, interviews, survey and a Material Driven Design process I will explore Japanese Knotweed as a material, which results in material samples and discussion. This opens up the possibilities for future markets.

L'objectif général de la thèse est d'examiner la variation et l'évolution des traits fonctionnels<p>susceptibles de sous-tendre des variations de capacité d'invasion, au sein du complexe de plantes envahissantes F. japonica, F. xbohemica et F. sachalinensis en Belgique. Ces trois taxons d'origine asiatique présentent un intérêt majeur en écologie des invasions car ils possèdent une aptitude à l'invasion contrastée bien qu'ils fassent partie du même complexe hybride, aient la même forme de vie, et la même distribution géographique. <p>En particulier, la thèse examine si Fallopia sachalinensis présente une combinaison particulière de traits fonctionnels liés à la capture et à l'utilisation des ressources susceptible d'expliquer sa capacité d'invasion plus faible. La thèse tâche également de déterminer si les hybrides sont intermédiaires entre les parents pour ces traits ou manifestent des propriétés originales susceptibles<p>d'entraîner un comportement plus invasif. Les traits fonctionnels pris en considération comprennent notamment l'architecture des parties aériennes, le SLA (surface foliaire spécifique), les teneurs foliaires en nutriments, la vitesse de décomposition des litières et la plasticité phénotypique de ces caractères. La stratégie scientifique repose sur trois approches complémentaires:<p>- des comparaisons in situ entre les taxons dans des sites ou ils coexistent;<p>- des cultures en conditions semi-contrôlées au jardin expérimental;<p>- une expérience de décomposition des litières.<p>Les résultats mettent en lumière la stratégie unique de capture et d'utilisation des ressources<p>de F. sachalinensis, ainsi que ses réponses plastiques moins adaptées (moins d'accroissement de la hauteur et de la surface foliaire totale en réponse a l'ombre, et de la biomasse et du nombre de tiges en réponse a une augmentation de la fertilité du sol). Cette stratégie contribue a sa capacité d'invasion plus faible en réduisant son efficacité d'utilisation et de capture de la lumière et des nutriments. D'autre part, l'hybride ne présente pas de valeurs transgressives pour les traits étudiés et est similaire à F. japonica en termes de traits et de plasticité. Toutefois, le nombre limité de<p>populations hybrides étudiées ne nous permet pas d'en conclure que l'hybride ne présente pas de<p>variation transgressive a l'échelle européenne. De plus, la variabilité génétique de l'hybride pourrait permettre une évolution future de sa capacité d'invasion, ce qui en fait une priorité pour la prévention et la gestion a l'échelle mondiale. / The objective of the thesis is to examine variation and evolution of functional traits that are susceptible to underlie variation of invasiveness in the invasive complex of Fallopia japonica, F. xbohemica and F. sachalinensis in Belgium. These three taxa originate from Asia and present a major interest in invasion ecology since they display contrasting invasiveness although they are part of the same hybrid complex, have the same life form and distribution area.<p>In particular, we ask if F. sachalinensis displays a specific combination of functional traits related to resource capture and use that is susceptible to explain its lower invasiveness. We also try to determine if the hybrids have intermediary trait values or if they show specific properties susceptible to increase their invasiveness. Functional traits measured include architecture, SLA (specific leaf area), nutrient foliar concentrations, litter decomposition rate and phenotypic plasticity of the same traits. Scientific strategy uses three different methods:<p>- in situ comparisons between the taxa in sites where they coexist;<p>- common gardens with semi controlled conditions;<p>- litter decomposition experiment.<p>Results show the unique strategy of F. sachalinensis concerning resource capture and use, as well as its less adaptive plastic responses (smaller increase of height and total leaf area in response to shade, and of biomass and shoot number in response to soil fertility). This strategy contributes to its lower invasiveness through a reduction in light and nutrient capture and use efficiency. The hybrid does not display transgressive variation for the studied traits and is similar to F. japonica concerning its traits and its plasticity. However, the limited number of hybrid accessions does not allow to conclude that the hybrid presents no transgressive variation throughout Europe. Moreover, genetic variability in the hybrid might allow future evolution of its invasiveness, making the hybrid a priority for prevention and management throughout the world. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Invasiva främmande arter utgör idag ett av de största hoten mot biologisk mångfald, både nationellt och globalt. Sveriges geografiska läge har medfört en relativt begränsad utbredning av invasiva främmande arter men problematiken förväntas öka med framtida klimatförändringar. SLU ArtDatabanken har därför riskklassificerat arter i Sverige utifrån deras potentiella ekologiska effekt på ekosystem samt deras invasionspotential. ArtDatabankens rapport ska ligga till grund för en framtida nationell förteckning där de invasiva främmande arterna med störst skadeverkan nationellt kommer att omfattas av svensk lagstiftning. I vår rapport undersöks vilka invasiva främmande landbaserade växter som utgör de största hoten mot ekskogar i Västra Götalands län. Resultatet kan ge ett underlag för att prioritera vilka invasiva främmande växtarter som Länsstyrelsen, i ett tidigt skede, bör rikta åtgärder mot för att bevara och skydda ekskogar i länet. Ek är särskilt skyddsvärt då släktet är ett av Europas viktigaste trädslag och utgör habitat för en stor mängd arter. Invasiva främmande växter kan utgöra ett hot mot ekskogar genom exempelvis beskuggning och konkurrens vilket kan påverka träden negativt.  Vi har i vår rapport baserat urvalet av invasiva främmande arter på ArtDatabankens risklista samt EU:s förteckning över invasiva främmande arter av unionsbetydelse. Arbetet utfördes som en GIS-analys och en fältstudie. GIS-analysen baserades på observationer i SLU Artportalen och i fältstudien inventerades 4 skyddade ekskogar i länet. De olika resultaten kan indikera på ett bristfälligt underlag i SLU Artportalen. Resultatet av GIS-analysen visade att det största hotet, både nutida och framtida, mot undersökta ekskogar var parkslide (Reynoutria japonica), medan fältstudien visade att druvfläder (Sambucus racemosa) utgjorde det största nutida hotet i inventerade ekskogar. Antalet observationer av invasiva främmande växter från vår artlista i tätortsnära ekskogar, med tillhörande buffertzoner om 2 kilometer, var fler än i ekskogar och dess buffertzoner som klassades som icke tätortsnära. Skillnaden i antal observationer var signifikant. Resultatet kan bekräfta att invasiva främmande växter är mer förekommande i och kring tätorter, varför hoten mot tätortsnära ekskogar kan vara större än mot icke tätortsnära. Detta överensstämmer med tidigare forskning som visar att spridning av invasiva främmande växter gynnas av mänskliga aktiviteter såsom trädgårdsodling samt hantering och transport av massor. / Invasive alien species pose one of the greatest threats against biodiversity, in Sweden and globally. The northern location of Sweden has limited the distribution of invasive alien species, however, issues concerning invasives are predicted to increase with future climate change. The Swedish University of Agricultural Sciences has compiled a report containing a list of more than 1000 invasive alien species which have been classified based on their ecological effect and invasion potential. The report will be the basis of the future national list of legislated species. In our report, we examine which invasive alien land-based plant species pose the greatest threats against oak tree forests in the county of Västra Götaland. Our results can be used to prioritize which invasive alien plant species the County Administrative Board, in an early stage, could direct measures against to protect oak tree forests in conservation management. The protection of oak is crucial since it is one of the most important genera in Europe, both economically and ecologically, entailing a national responsibility. Shading and competition are major threats, affecting oak trees negatively and prohibiting rejuvenation.   The species selected for analysis in our report was based on the list of invasive alien species compiled by the Swedish University of Agricultural Sciences in combination with the EU’s list of species of union concern. This report contains a GIS analysis and a field study. The GIS analysis was based on observational data in SLU Artportalen and in the field study, 4 protected oak tree forests were surveyed. The difference in results may indicate inadequate data in SLU Artportalen. Our GIS analysis showed that Japanese knotweed (Reynoutria japonica) posed the largest present and future threat against analyzed oak tree forests, while red-berried elder (Sambucus racemosa) posed the largest present threat against examined oak tree forest according to the survey in our field study. The number of observations of selected invasive alien plant species in oak tree forests, with associated surrounding buffer zones of 2 km, close to urban areas was higher than in oak tree forest, with associated buffer zones, not close to urban areas. The difference in number of observations was significant. Our result can confirm that invasive alien plant species are more numerous in urban areas than in non-urban areas, meaning the threat against oak tree forest close to urban areas may be greater. This corresponds with previous research showing that the dispersal of invasive alien plant species is promoted by human activities, such as gardening and the disposal and transportation of waste from excavations.

My thesis deals with dye plants and possibilities of their use. The first part contains classification of dye plants and history of their use. In the next part, there is a summary of dye plants and colors we can get from them. Methodology of coloring is also introduced. At the end, there are botanic parameters, environment needs and cultivation methods of eight selected dye plants. The thesis include database of dye plants in electronic form.