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Memoria para optar al Título Profesional de Ingeniero Agrónomo Mención: Sanidad Vegetal / Durante la temporada 2002-03 se estudió el efecto del polen de Helianthus annus L. (maravilla), Eschscholtzia californica Cham. (dedal de oro), Convolvulus arvensis L. (correhuela), Brassica rapa L. (yuyo), Raphanus sativus L. (rábano), Senecio vulgaris L. (senecio) y Taraxacum officinale Wever ex Wiggers (diente de león) en la sobrevivencia de los individuos, fertilidad y viabilidad de los huevos de Neoseiulus californicus (McGregor) en laboratorio.

Memoria para optar al título profesional de Ingeniero en Recursos Naturales Renovables / Los combustibles fósiles son fuentes de energía que provienen de los restos de plantas y animales. Se necesitan millones de años para que se formen y según la Agencia Internacional de Energía, el 86% del consumo mundial de energía proviene del petróleo y a medida que los países se industrializan y sus poblaciones aumentan, también crece el consumo de energía. El agotamiento de las fuentes tradicionales de combustibles fósiles ha puesto a la mayoría de los países a encontrar soluciones en energías alternativas y sostenibles, que provengan de fuentes renovables, de bajo impacto ambiental y que reduzcan las emisiones de efecto invernadero. En las últimas décadas, la economía chilena ha tenido un significativo incremento del consumo de energía. El país es dependiente de las importaciones y el uso de la energía es menos eficiente que en el resto del mundo. Como consecuencia, el costo de la energía es alto en comparación internacional, por lo que es necesario buscar formas de diversificar la matriz energética, y reducir la dependencia de Chile de combustibles fósiles importados, para asegurar su estabilidad económica y reducir los impactos ambientales asociados al consumo de estos. El objetivo y propósito principal de esta investigación fue identificar áreas con potencial para el establecimiento de plantaciones de Diente de León común y de Diente de León Ruso con fines bioenergéticos en Chile. La propuesta se basa en la selección y categorización de variables climáticas y edáficas, la construcción del modelo cartográfico y la síntesis cartográfica. La identificación de las potenciales áreas de establecimiento fue analizada utilizando una metodología de algebra de mapas y combinatoria de las variables agroclimáticas. Los rangos y criterios de adaptabilidad identificados se evaluaron basados en una escala de clasificación que da cuenta de zonas con diferente grado de adaptabilidad y zonas con distintos niveles de restricción relacionadas a temperatura, disponibilidad hídrica y/o suelo. Se identificaron 15.539.813 ha con potencial para el establecimiento del Diente de León en Chile, las que se clasifican en: 6.392.014,2 ha Aptas, 4.540.562,5 ha Optimas y 4.607.236,4 ha Marginalmente Aptas. La zona costera de la V Región de Valparaíso, es la que muestra la mayor potencialidad para el establecimiento de esta especie, con aptitud térmica e hídrica óptima, y suelos ricos materia orgánica. Los resultados generados constituyen una aproximación para identificar sitios de interés para el desarrollo del Diente de León como especie energética. / Fossil fuels are an energy source that comes from the remains of plants and animals. It takes millions of years for them to form and according to the International Energy Agency, about 86% of global energy consumption comes from oil, and as countries industrialize and population increases, so does the power consumption. The depletion of traditional fossil fuels sources has made most countries to look for solutions in alternative and sustainable energy coming from renewable sources, with low environmental impact and minimal greenhouse emissions. In recent decades, Chile's economy has had a significant increase in power consumption. The country is heavily dependent on imports and the use of energy is less efficient compared to the rest of the world. As a result, the energy cost is high in contrast with other nations, so it is necessary to find ways to diversify energy sources and reduce dependence on imported fossil fuels of the country, to ensure economic stability and reduce the environmental impacts associated with this fuel consumption. The intents and main objective of this research was to identify potential areas for the establishment of plantation for common Dandelion and Russian Dandelion with bioenergy purposes in Chile. The proposal is based on the selection and categorization of climatic and soil variables, construction of a cartographic model and a cartographic synthesis. Identifying the potential areas of establishment was analyzed using a methodology of mapping algebra and combination of agroclimatic parameters. Ranges and adaptability criteria identified were evaluated based on a rating scale that show areas with different scales of adaptability and areas with different levels of restriction related to temperature, water availability and / or soil . 15.539.813 ha were identified with potential for the establishment of Dandelion in Chile, which are classified as suitable with 6.392.014,2 ha, optimal with 4.540.562,5 ha and marginally suitable 4.607.236,4 ha. The coastal area of the V Region of Valparaiso is showing the greatest potential for the establishment of this species, with optimal thermal and water suitability; and soil with rich organic matter. The results generated are an approach to identify sites of interest for the development of Dandelion as energetic species.

Memoria para optar al título profesional de: Ingeniero en Recursos Naturales Renovables / Los combustibles fósiles son fuentes de energía que provienen de los restos de plantas y animales. Se necesitan millones de años para que se formen y según la Agencia Internacional de Energía, el 86% del consumo mundial de energía proviene del petróleo y a medida que los países se industrializan y sus poblaciones aumentan, también crece el consumo de energía. El agotamiento de las fuentes tradicionales de combustibles fósiles ha puesto a la mayoría de los países a encontrar soluciones en energías alternativas y sostenibles, que provengan de fuentes renovables, de bajo impacto ambiental y que reduzcan las emisiones de efecto invernadero. En las últimas décadas, la economía chilena ha tenido un significativo incremento del consumo de energía. El país es dependiente de las importaciones y el uso de la energía es menos eficiente que en el resto del mundo. Como consecuencia, el costo de la energía es alto en comparación internacional, por lo que es necesario buscar formas de diversificar la matriz energética, y reducir la dependencia de Chile de combustibles fósiles importados, para asegurar su estabilidad económica y reducir los impactos ambientales asociados al consumo de estos. El objetivo y propósito principal de esta investigación fue identificar áreas con potencial para el establecimiento de plantaciones de Diente de León común y de Diente de León Ruso con fines bioenergéticos en Chile. La propuesta se basa en la selección y categorización de variables climáticas y edáficas, la construcción del modelo cartográfico y la síntesis cartográfica. La identificación de las potenciales áreas de establecimiento fue analizada utilizando una metodología de algebra de mapas y combinatoria de las variables agroclimáticas. Los rangos y criterios de adaptabilidad identificados se evaluaron basados en una escala de clasificación que da cuenta de zonas con diferente grado de adaptabilidad y zonas con distintos niveles de restricción relacionadas a temperatura, disponibilidad hídrica y/o suelo. Se identificaron 15.539.813 ha con potencial para el establecimiento del Diente de León en Chile, las que se clasifican en: 6.392.014,2 ha Aptas, 4.540.562,5 ha Optimas y 4.607.236,4 ha Marginalmente Aptas. La zona costera de la V Región de Valparaíso, es la que muestra la mayor potencialidad para el establecimiento de esta especie, con aptitud térmica e hídrica óptima, y suelos ricos materia orgánica. Los resultados generados constituyen una aproximación para identificar sitios de interés para el desarrollo del Diente de León como especie energética. / Fossil fuels are an energy source that comes from the remains of plants and animals. It takes millions of years for them to form and according to the International Energy Agency, about 86% of global energy consumption comes from oil, and as countries industrialize and population increases, so does the power consumption. The depletion of traditional fossil fuels sources has made most countries to look for solutions in alternative and sustainable energy coming from renewable sources, with low environmental impact and minimal greenhouse emissions. In recent decades, Chile's economy has had a significant increase in power consumption. The country is heavily dependent on imports and the use of energy is less efficient compared to the rest of the world. As a result, the energy cost is high in contrast with other nations, so it is necessary to find ways to diversify energy sources and reduce dependence on imported fossil fuels of the country, to ensure economic stability and reduce the environmental impacts associated with this fuel consumption. The intents and main objective of this research was to identify potential areas for the establishment of plantation for common Dandelion and Russian Dandelion with bioenergy purposes in Chile. The proposal is based on the selection and categorization of climatic and soil variables, construction of a cartographic model and a cartographic synthesis. Identifying the potential areas of establishment was analyzed using a methodology of mapping algebra and combination of agroclimatic parameters. Ranges and adaptability criteria identified were evaluated based on a rating scale that show areas with different scales of adaptability and areas with different levels of restriction related to temperature, water availability and / or soil . 15.539.813 ha were identified with potential for the establishment of Dandelion in Chile, which are classified as suitable with 6.392.014,2 ha, optimal with 4.540.562,5 ha and marginally suitable 4.607.236,4 ha. The coastal area of the V Region of Valparaiso is showing the greatest potential for the establishment of this species, with optimal thermal and water suitability; and soil with rich organic matter. The results generated are an approach to identify sites of interest for the development of Dandelion as energetic species.

Master of Science / Department of Horticulture, Forestry, and Recreation Resources / Steven Keeley / Common dandelion (Taraxacum officinale Weber) is an important perennial weed in turfgrass. Fall is considered the optimal time for postemergence herbicidal control of dandelions; however, applications in spring, when volatility damage to surrounding plants is an additional concern, are often needed. Therefore, we conducted research to determine the volatility of common broadleaf herbicides, and their efficacy when applied at spring and fall application timings. Volatility was determined by applying herbicides to turfgrass and using potted tomatoes as indicator plants. Tomatoes exposed to turfgrass treated with Trimec Classic, Confront, Surge, Escalade 2, and Imprelis exhibited little or no volatility damage, while exposure to Speedzone, 4 Speed XT, and Cool Power caused significant damage. In general, herbicides causing little or no damage were amine formulations. Two field studies determined the effect of spring and fall application timing on dandelion control with several herbicides. Herbicide applications in the spring coincided with dandelion anthesis stages: pre-bloom, peak bloom, and post-bloom. Results were dependent on dandelion pressure in the studies. In 2010, with lower pressure, there were no differences among herbicides at any spring timing when dandelion control was evaluated after one year; all herbicides gave ≥ 80% control. In 2011, with higher dandelion pressure, Imprelis SL and 4 Speed XT provided ≥ 96% dandelion control at the spring pre- and post-bloom timings, which was better than Surge, Escalade 2, Cool Power, and Confront. The best choices for spring efficacy combined with minimal to no volatility were Escalade 2 and Trimec Classic. Finally, because interest in organic dandelion control is increasing, we compared several organic weed control tactics with a conventional herbicide. In a two-year field study, the conventional herbicide gave much better control (> 96%) than any organic method. Horticultural vinegar corn gluten meal, and fertilizer-only gave < 25% control, while hand-weeding gave 58 to 71% control. While hand-weeding was the best of the organic tactics, the time required was considered prohibitive for turfgrass managers, unless initial weed levels were very low.

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Comprendre le fonctionnement des écosystèmes est un enjeu crucial, en particulier dans un contexte de changements globaux. Afin de mieux prédire les processus écosystémiques, j’ai testé la précision et les limites des hypothèses du biomass-ratio de Grime (HBMR) et de l’annulation idiosyncratique (HAI), cette dernière étant une hypothèse originale de cette thèse. Pour cela, j’ai appliqué le principe du biomass-ratio aux traits fonctionnels, en employant la méthode des traits agrégés en communauté, pour estimer la réponse globale des espèces en mélange. La décomposition des litières plurispécifiques constitue un bon modèle biologique, pour lequel je me suis posé les questions suivantes : (1) est-ce que l’HBMR prédit bien les taux de décomposition en mélanges plurispécifiques ? ; (2) est-ce que le degré de variabilité de ces taux diminue pour des raisons biologiques avec l’augmentation de la richesse spécifique (RS) des mélanges (HAI) ? ; (3) est-ce que la variabilité des taux entre mélanges diminue quand les conditions abiotiques du site deviennent plus limitantes ? ; (4)considérant que les mélanges plus contrastés fonctionnellement sont susceptibles de développer plus d’interactions, est-ce que la déviation à la prédiction augmente avec la dispersion fonctionnelle des mélanges(« FDis », La liberté & Legendre 2010) ? Cette thèse inclut deux expériences de décomposition en sachets à litières : (1) à Sherbrooke (QC, Canada) avec des microcosmes, impliquant des litières de six espèces d’arbres, décomposant seules et en mélanges et (2) sur trois sites au climat contrasté dans la région de Clermont-Ferrand (France) avec des litières de quatre espèces d’herbacées, décomposant seules et en mélanges. Les résultats montrent des déviations positives et négatives par rapport aux taux prédits, mais l’HBMR décrit bien la réponse moyenne des litières plurispécifiques. Bien que l’HAI ait été rejetée, les résultats montrent une convergence des taux observés vers les taux prédits quand (1) la RS des mélanges augmente, (2)l’échelle spatiale augmente et (3) le climat est plus limitant pour la décomposition. Enfin, malgré des corrélations entre FDis et interactions entre espèces dans les litières, cette relation n’est pas généralisable et l’hypothèse de corrélation positive entre FDis et déviation à l’HBMR a été rejetée. / Understanding ecosystem functioning is a key goal in ecology, especially in the context of global changes. To better predict ecosystem processes, I tested the accuracy and the limits of Grime’s biomass-ratio (BMRH) hypothesis and a novel idiosyncratic annulment (IAH) hypothesis. I applied the biomass-ratio to functional traits, using the community-weighted means (CWM) to estimate the global response of species in mixtures. I studied the decomposition of litter species mixtures as a biological model and asked the following questions : (1) does the BMRH predict well the decomposition rates of mixed species litters ? ; (2) does the degree of variability of these rates decrease with increasing species richness (SR) beyond that expected from purely mathematical causes (IAH) ? ; (3) does the variability of rates between mixtures decrease with less favourable abiotic conditions for decomposition ? ; (4) as more functionally contrasted mixtures are expected to develop more interactions, does the deviation from prediction increase with increasing functional dispersion in mixtures (« FDis », Laliberté & Legendre 2010) ? This study involves two decomposition experiments using litterbags : (1) at Sherbrooke (QC, Canada), in microcosms, involving litters from six tree species, decomposed alone and in mixtures and (2) in three climatically contrasted sites in the region of Clermont-Ferrand (France) with litters from four herbaceous species, decomposed alone and in mixtures. Despite both positive and negative deviations from expectation occurring at all levels of SR, the BMRH well described the average response of mixed species litters. Although I rejected the IAH, the results showed a convergence to the predicted values based on CWM with (1) increasing the SR in mixtures, (2) increasing the spatial scale of the study and (3) a less favourable climate to decomposition. Finally, although there was a correlation between litter interactions and functional divergence, this relationship was not generalizable and I rejected the hypothesis of a positive correlation between FDis and the deviations from BMRH.

Sommaire : Comprendre le fonctionnement des écosystèmes est un enjeu crucial, en particulier dans un contexte de changements globaux. Afin de mieux prédire les processus écosystémiques, j’ai testé la précision et les limites des hypothèses du biomass-ratio de Grime (HBMR) et de l’annulation idiosyncratique (HAI), cette dernière étant une hypothèse originale de cette thèse. Pour cela, j’ai appliqué le principe du biomass-ratio aux traits fonctionnels, en employant la méthode des traits agrégés en communauté, pour estimer la réponse globale des espèces en mélange. La décomposition des litières plurispécifiques constitue un bon modèle biologique, pour lequel je me suis posé les questions suivantes : (1) est-ce que l’HBMR prédit bien les taux de décomposition en mélanges plurispécifiques ? ; (2) est-ce que le degré de variabilité de ces taux diminue pour des raisons biologiques avec l’augmentation de la richesse spécifique (RS) des mélanges (HAI) ? ; (3) est-ce que la variabilité des taux entre mélanges diminue quand les conditions abiotiques du site deviennent plus limitantes ? ; (4) considérant que les mélanges plus contrastés fonctionnellement sont susceptibles de développer plus d’interactions, est-ce que la déviation à la prédiction augmente avec la dispersion fonctionnelle des mélanges (« FDis », Laliberté & Legendre 2010) ? Cette thèse inclut deux expériences de décomposition en sachets à litières : (1) à Sherbrooke (QC, Canada) avec des microcosmes, impliquant des litières de six espèces d’arbres, décomposant seules et en mélanges et (2) sur trois sites au climat contrasté dans la région de Clermont-Ferrand (France) avec des litières de quatre espèces d’herbacées, décomposant seules et en mélanges. Les résultats montrent des déviations positives et négatives par rapport aux taux prédits, mais l’HBMR décrit bien la réponse moyenne des litières plurispécifiques. Bien que l’HAI ait été rejetée, les résultats montrent une convergence des taux observés vers les taux prédits quand (1) la RS des mélanges augmente, (2) l’échelle spatiale augmente et (3) le climat est plus limitant pour la décomposition. Enfin, malgré des corrélations entre FDis et interactions entre espèces dans les litières, cette relation n’est pas généralisable et l’hypothèse de corrélation positive entre FDis et déviation à l’HBMR a été rejetée. // Abstract : Understanding ecosystem functioning is a key goal in ecology, especially in the context of global changes. To better predict ecosystem processes, I tested the accuracy and the limits of Grime’s biomass-ratio (BMRH) hypothesis and a novel idiosyncratic annulment (IAH) hypothesis. I applied the biomass-ratio to functional traits, using the community-weighted means (CWM) to estimate the global response of species in mixtures. I studied the decomposition of litter species mixtures as a biological model and asked the following questions : (1) does the BMRH predict well the decomposition rates of mixed species litters? ; (2) does the degree of variability of these rates decrease with increasing species richness (SR) beyond that expected from purely mathematical causes (IAH)? ; (3) does the variability of rates between mixtures decrease with less favourable abiotic conditions for decomposition? ; (4) as more functionally contrasted mixtures are expected to develop more interactions, does the deviation from prediction increase with increasing functional dispersion in mixtures (« FDis », Laliberté & Legendre 2010)? This study involves two decomposition experiments using litterbags: (1) at Sherbrooke (QC, Canada), in microcosms, involving litters from six tree species, decomposed alone and in mixtures and (2) in three climatically contrasted sites in the region of Clermont-Ferrand (France) with litters from four herbaceous species, decomposed alone and in mixtures. Despite both positive and negative deviations from expectation occurring at all levels of SR, the BMRH well described the average response of mixed species litters. Although I rejected the IAH, the results showed a convergence to the predicted values based on CWM with (1) increasing the SR in mixtures, (2) increasing the spatial scale of the study and (3) a less favourable climate to decomposition. Finally, although there was a correlation between litter interactions and functional divergence, this relationship was not generalizable and I rejected the hypothesis of a positive correlation between FDis and the deviations from BMRH.

Sommaire : Comprendre le fonctionnement des e??cosyste??mes est un enjeu crucial, en particulier dans un contexte de changements globaux. Afin de mieux pre??dire les processus e??cosyste??miques, j???ai teste?? la pre??cision et les limites des hypothe??ses du biomass-ratio de Grime (HBMR) et de l???annulation idiosyncratique (HAI), cette dernie??re e??tant une hypothe??se originale de cette the??se. Pour cela, j???ai applique?? le principe du biomass-ratio aux traits fonctionnels, en employant la me??thode des traits agre??ge??s en communaute??, pour estimer la re??ponse globale des espe??ces en me??lange. La de??composition des litie??res plurispe??cifiques constitue un bon mode??le biologique, pour lequel je me suis pose?? les questions suivantes : (1) est-ce que l???HBMR pre??dit bien les taux de de??composition en me??langes plurispe??cifiques ? ; (2) est-ce que le degre?? de variabilite?? de ces taux diminue pour des raisons biologiques avec l???augmentation de la richesse spe??cifique (RS) des me??langes (HAI) ? ; (3) est-ce que la variabilite?? des taux entre me??langes diminue quand les conditions abiotiques du site deviennent plus limitantes ? ; (4) conside??rant que les me??langes plus contraste??s fonctionnellement sont susceptibles de de??velopper plus d???interactions, est-ce que la de??viation a?? la pre??diction augmente avec la dispersion fonctionnelle des me??langes (?? FDis ??, Laliberte?? & Legendre 2010) ? Cette the??se inclut deux expe??riences de de??composition en sachets a?? litie??res : (1) a?? Sherbrooke (QC, Canada) avec des microcosmes, impliquant des litie??res de six espe??ces d???arbres, de??composant seules et en me??langes et (2) sur trois sites au climat contraste?? dans la re??gion de Clermont-Ferrand (France) avec des litie??res de quatre espe??ces d???herbace??es, de??composant seules et en me??langes. Les re??sultats montrent des de??viations positives et ne??gatives par rapport aux taux pre??dits, mais l???HBMR de??crit bien la re??ponse moyenne des litie??res plurispe??cifiques. Bien que l???HAI ait e??te?? rejete??e, les re??sultats montrent une convergence des taux observe??s vers les taux pre??dits quand (1) la RS des me??langes augmente, (2) l???e??chelle spatiale augmente et (3) le climat est plus limitant pour la de??composition. Enfin, malgre?? des corre??lations entre FDis et interactions entre espe??ces dans les litie??res, cette relation n???est pas ge??ne??ralisable et l???hypothe??se de corre??lation positive entre FDis et de??viation a?? l???HBMR a e??te?? rejete??e. // Abstract : Understanding ecosystem functioning is a key goal in ecology, especially in the context of global changes. To better predict ecosystem processes, I tested the accuracy and the limits of Grime???s biomass-ratio (BMRH) hypothesis and a novel idiosyncratic annulment (IAH) hypothesis. I applied the biomass-ratio to functional traits, using the community-weighted means (CWM) to estimate the global response of species in mixtures. I studied the decomposition of litter species mixtures as a biological model and asked the following questions : (1) does the BMRH predict well the decomposition rates of mixed species litters? ; (2) does the degree of variability of these rates decrease with increasing species richness (SR) beyond that expected from purely mathematical causes (IAH)? ; (3) does the variability of rates between mixtures decrease with less favourable abiotic conditions for decomposition? ; (4) as more functionally contrasted mixtures are expected to develop more interactions, does the deviation from prediction increase with increasing functional dispersion in mixtures (?? FDis ??, Lalibert?? & Legendre 2010)? This study involves two decomposition experiments using litterbags: (1) at Sherbrooke (QC, Canada), in microcosms, involving litters from six tree species, decomposed alone and in mixtures and (2) in three climatically contrasted sites in the region of Clermont-Ferrand (France) with litters from four herbaceous species, decomposed alone and in mixtures. Despite both positive and negative deviations from expectation occurring at all levels of SR, the BMRH well described the average response of mixed species litters. Although I rejected the IAH, the results showed a convergence to the predicted values based on CWM with (1) increasing the SR in mixtures, (2) increasing the spatial scale of the study and (3) a less favourable climate to decomposition. Finally, although there was a correlation between litter interactions and functional divergence, this relationship was not generalizable and I rejected the hypothesis of a positive correlation between FDis and the deviations from BMRH.