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Memoria para optar al título profesional de Ingeniero en Recursos Naturales Renovables / La humedad del suelo es un parámetro clave para diversas aplicaciones ambientales, hidrológicas, meteorológicas y actividades productivas relacionadas con los sistemas silvoagropecuarios. Dentro de los métodos para obtener información de la humedad de suelo, las mediciones in-situ son esenciales para analizar la transferencia de energía en modelos suelo-vegetación-atmósfera y la validación de métodos indirectos para la estimación de esta variable. Por esto, contar con métodos confiables, robustos y sistematizados de mediciones in-situ es requerido para la obtención de modelos ambientales óptimos

Thesis (M.Sc) (Agriculture) --University of Limpopo,2009. / The study was conducted to determine the effect of dietary energy level and tanniniferous Acacia karroo leaf meal level of supplementation at finisher stage on performance and carcass characteristics of male and female Ross 308 broiler chickens. Three hundred and sixty, 21-day old male and female broiler chickens were assigned to twelve treatments with three replications of ten birds in a 2 (sex) x 3 (dietary energy level) x 3 (tanniniferous Acacia karroo leaf meal level) factorial, complete randomized design. Supplementation with Acacia karroo leaf meal had no effect on diet intake, digestibility and live weight of broiler chickens. However, supplementation with 9 and 12 g of Acacia karroo leaf meal per kg DM feed reduced fat pad weights in male broiler chickens by 26 and 29 percentage points, respectively. Similarly, supplementation with 9 and 12 g of Acacia karroo leaf meal per kg DM feed reduced fat pad weights in female chickens by 26 percentage points. These reductions were achieved without any significant reduction in feed intake and digestibility. However, the physiological explanation for this effect is not clear and it, thus, merits further investigation. / National Research Foundation.

Thèse de doctorat : Sciences physique et de l'ingénieur. Sciences du bois : Bordeaux 1 : 2008. Thèse de doctorat : Sciences physique et de l'ingénieur. Sciences du bois : Université Cheikh Anta Diop de Dakar : 2008. / Titre provenant de l'écran-titre.

Disturbances, such as herbivory and fire are commonplace in savanna ecosystems. The effects of herbivory and fire on growth and defences of adult trees is a much studied filed in plant ecology. However, there are comparatively few studies that have investigated the effects of herbivory and fire on seedling growth, defences and establishment. African Acacia trees are common and widespread, and are suggested to be keystone species in savanna ecosystems. They have been shown to significantly positively increase soil characteristics, such as soil moisture and infiltration, while also increasing spatial heterogeneity of savannas. These trees are distinguishable by their array of physical and chemical defences. Physical defences are either in the form of spines (physiologically costly to produce, thus considered inducible) or prickles (physiologically cheap to produce, thus considered constitutive), while condensed tannins are the most common form of chemical defences. Adult Acacia trees have been shown on several occasions to be highly resilient to disturbance events, primarily due to their large size. However, the effects of herbivory and fire on Acacia seedlings have been little studied despite their apparent importance for our understanding of African savanna ecosystem functioning. In two separate experiments, this thesis aimed to investigate the individual and combined effects of simulated herbivory and fire on the regrowth, defences, and total non-structural carbohydrates (TNC) of the seedlings of several Acacia species, while also testing the Resource Availability Hypothesis (RAH) (14 Acacia species) and the Expanded Growth-Differentiation Balance Hypothesis (GDBH) (three Acacia species). The RAH (Coley, Bryant & Chapin 1985) and the GDBH (Loomis 1932) both assume that arid-adapted (resource-poor) species are slow growing, with low tissue turnover rates. Contrastingly, humid-adapted (resource-rich) species have fast growth rates and thus a high tissue turnover rate. Therefore, arid-adapted species are predicted to invest more carbohydrate reserves in defence after a disturbance event, in order to defend new photosynthetic material. Conversely, humid-adapted (resource-rich) species are predicted to invest carbohydrate reserves into increased growth after a disturbance event, in order to compensate for tissue loss. The first greenhouse experiment found that, in accordance with the RAH, humid-adapted species displayed elevated growth rates compared to arid-adapted species. Overall, defences significantly increased after herbivory, but significantly decreased after fire. Herbivory was also shown to significantly reduce TNC stores in roots more than fire. We found that arid-adapted species did indeed invest more carbohydrate stores (TNC) into defence, and displaying an increase in spine and prickle abundance, spine and prickle length, and condensed tannin concentration. Humid-adapted species displayed an increase in growth rather than in defence, with the majority of species only increasing one defensive trait. Humid-adapted species also displayed significant trade-offs (negative correlations) between new stem growth and defence traits, while arid-adapted species overall did not display any significant trade-offs between stem growth and increased defences. The majority of arid-adapted species also displayed an allometric effect for spine abundance and length, with an increase in one trait led to an increase in the other. Prickles were found to be inducible, despite the assumption that due to low physiological cost, they are no inducible. Herbivory and fire were shown to not be substitutable in their effects on Acacia seedlings in a controlled experimental setting. The second greenhouse experiment tested the Expanded Growth-Differentiation Balance Hypothesis (GDBH) in the seedlings of A. erioloba, A. karroo, and A. nilotica using five levels of nutrient availability. Overall, spine abundance and spine length displayed a unimodal trend in all three species, with spine abundance and spine length being greatest at a nutrient availability of 800 mg/ ℓ. Spine abundance, spine length and condensed tannins increased significantly after herbivory, but were shown to significantly decrease after fire. We found that with an increase in nutrient availability, the growth of stems and roots, along with the production of TNC in roots and stems of all species significantly increased. Our data provide mixed support for the assumptions and predictions of the expanded GDBH. The regrowth of stems and physical defences were consistent with the GDBH. Chemical defences (i.e. condensed tannins) were however, inconsistent with the predictions of the GDBH. We have shown that Acacia seedlings are highly resilient to disturbance events, while the growth responses of Acacia seedlings are underpinned by TNC stores in roots. Simulated herbivory and fire are often substituted for one another in controlled experiments. However, we have shown that the effects of herbivory and fire have significantly different effects on regrowth patterns of Acacia seedlings. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.

[Abstract]: Agricultural intensification, involving habitat fragmentation and modification, typically leads to a decline in biodiversity and ecosystem function. While most studies concentrate on remnant patches, the less intensively managed components of agricultural landscapes may also provide biodiversity values and ecosystem services. This study examines the contribution of different categories of land management to biodiversity and ecosystem function along a gradient of agricultural intensification. Differences within these land management categories are also examined. Research results are interpreted in the broad context of ecosystem services and their resilience in agro-ecosystems.

Thesis (Ph. D.)--University of Adelaide, Dept. of Botany, 1985. / Includes bibliographical references (leaves [347]-361).

Orientador : Prof. Dr. Antonio Rioyei Higa / Coorientadora : Profª. Drª. Giovana Bomfim de Alcantara / Dissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Agrárias, Programa de Pós-Graduação em Engenharia Florestal. Defesa: Curitiba, 20/02/2017 / Inclui referências : f.115-118 / Resumo: Dentre as poucas espécies florestais utilizadas para a extração de tanino destaca-se Acacia mearnsii De Wildeman (acácia negra), originária da Austrália e plantada comercialmente no Rio grande do Sul. Devido ao grande interesse comercial, busca-se otimizar técnicas de propagação clonal da espécie almejando sua silvicultura clonal em larga escala para a extração de tanino e cavacos. Baseado no exposto, o presente trabalho teve como objetivo geral avaliar aspectos da clonagem de genótipos de acácia negra por meio de técnicas de resgate e de miniestaquia. Para tanto o trabalho foi dividido em três capítulos. O primeiro capítulo aborda técnicas de indução de brotações em indivíduos adultos de acácia negra por diferentes métodos em diferentes alturas, avaliando-se a capacidade de rebrota de matrizes com 3 e 5 anos de idade e o desempenho dessas técnicas nas quatro estações do ano. O segundo capítulo baseia-se no manejo do minijardim clonal da espécie, nas estações de verão, outono e inverno, quanto ao controle de temperatura e umidade avaliando-se o emprego de cobertura plástica (estufim) sobre o sistema de produção das minicepas. E por fim, o terceiro capítulo, dividido em 4 experimentos, trata da dinâmica de enraizamento de miniestacas quanto a diferentes formas de aplicação e concentrações de ácido indol butírico (AIB), diferentes antioxidantes e suas diferentes concentrações, diferentes tamanhos e tipos de miniestacas aplicados a três diferentes materiais genéticos. Em termos gerais, o uso da técnica de torniquete é o método mais eficiente para a indução de brotações em acácia negra nas estações de outono e inverno, já nas estações mais quentes o método mais eficiente é a decepa, e as alturas de 1,20 e 2,0 m proporcionam maior quantidade de brotações por indivíduo. As minicepas em jardim clonal, sobrevivem bem nos quatro ambientes de minijardim manejados. A estação de verão apresenta as melhores respostas aos tratamentos, porém, no inverno, o uso do estufim fora da casa de vegetação apresenta resultados promissores, principalmente para enraizamento de miniestacas coletadas do minijardim. Quanto ao terceiro estudo, os resultados mostram que existe predisposição da espécie ao enraizamento, com alta capacidade de formar sistema radicial. A concentração de AIB influencia nas respostas ao enraizamento, principalmente nas concentrações de 4000 e 6000 mg L-1, enquanto que a forma de aplicação do regulador tem pouca influência. A concentração dos antioxidantes polivinilpirrolidona (PVP) e ácido ascórbico não influencia nos resultados de enraizamento. Apenas a concentração de 1000 mg L-1 de carvão ativado é que contribui para maiores taxas de enraizamento do que os demais antioxidantes. A posição da miniestaca, não tem influência nos resultados de enraizamento para nenhum dos clones estudados, já a permanência das folhas na confecção da miniestaca promove maiores taxas de enraizamento. O comprimento da miniestaca influencia nas respostas ao enraizamento sendo o tamanho de 14 cm o mais indicado. O material genético (clone) responde de maneira diferenciada na propagação vegetativa por miniestaquia da espécie. Palavras-chave: clonagem, enraizamento adventício, resgate. / Abstract: Among the few forest species used for tannin extraction are Acacia mearnsii De Wildeman (black wattle), which originated in Australia and is commercially planted in Rio Grande do Sul. Due to the great commercial interest, the aim is to optimize clonal propagation techniques Species by targeting their large-scale clonal forestry for tannin and chip extraction. Based on the above, the present work had as general objective to evaluate aspects of the cloning of black wattle genotypes by means of rescue techniques and minicuttings. For this, the work was divided into three chapters. The first chapter deals with shoot induction techniques in adult black wattle individuals by different methods at different heights, evaluating the regrowth capacity of 3 and 5 year-old matrices and the performance of these techniques in the four seasons of the year. The second chapter is based on the management of the clonal hedge of the species, in the summer, autumn and winter seasons, in terms of temperature and humidity control, evaluating the use of a plastic cover over the ministumps production system. Finally, the third chapter, divided in four experiments, deals with the dynamics of minicut rooting in different forms of application and concentrations of indole butyric acid (IBA), different antioxidants and their different concentrations, different sizes and types of minicuts applied to three different genetic materials. In general terms, the use of tourniquet technique is the most efficient method for the induction of black wattle shoots in the autumn and winter seasons. In the hottest seasons, the most efficient method is the cutter, and the heights of 1.20 and 2.0 m provide more shoots per individual. Clonal hedge ministumps survive well in four managed clonal hedge environments. The summer season presents the best responses to treatments, however, in winter, the use of the minitunnel outside the greenhouse presents promising results, mainly for rooting minicut collected from the clonal hedge. Regarding the third study, the results show that there is predisposition of the species to rooting, with high capacity to form a root system. The concentration of IBA influences the responses to rooting, especially in the concentrations of 4000 and 6000 mg L-1, while the application of the regulator has little influence. The concentration of the antioxidants polyvinylpyrrolidone (PVP) and ascorbic acid does not influence the rooting results. Only the concentration of 1000 mg L-1 of activated carbon is who contributes to higher rooting rates than the other antioxidants. The minicut position has no influence on the rooting results for any of the clones studied, since the permanence of the leaves in the minicut making confers higher rooting rates. The minicut length influences rooting responses, with a 14 cm size being the most indicated. The genetic material (clone) responds differently in the vegetative propagation by minicutting of the species. Key-words: cloning, adventitious rooting, rescue.

Orientador: Vitor Alberto Kerber / Co-orientador: Obdulio Gomes Miguel / Dissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências da Saúde / Resumo: Acacia /ongifolia (Andr.) Willd., é um arbusto, de 3-4 m de altura. Arbusto originário da região leste-tropical da Austrália, muito cultivado para fixar dunas em terrenos íngremes, sujeitos a erosão. Acacia longifolia (Andr.) Willd. foi investigada visando à identificação dos flavonóides majoritários em suas flores e a avaliação de atividades antimicrobianas. Através de métodos cromatográficos, três flavonóides foram isolados a partir da fração acetato de etila. Estes foram identificados através de análises espectroscópicas e propriedades físico-químicas como uma flavanona a naringenina, e dois de seus heterosídeos, a 5-f3-0-galactosil-naringenina e 5-f3-Dglucosil- naringenina. Usando CLAE, os flavonóides isolados foram quantificados no material vegetal, apresentando teores mínimos de 0,582 % (m/m) de 5-f3-Dgalactosil- naringenina, 0,2% (mim) de 5-f3-0-glucosil-naringenina e 0,018 % (mim) de naringenina. A fração acetato de etila a uma concentração de 500 ppm, mostrou uma significativa atividade antifúngica, inibindo 30% do crescimento micelial de Rhizoctonia sp. Também houve inibição do crescimento micelial de Colletotrichum acutatum (15,9%) e de Fusarium oxysporum (10,5 %). O extrato bruto etanólico e as frações acetato de etila e diclorometano foram testadas contra as cepas de Staphy/ococcus aureus, S. epidermidis e Escherichia colí em concentrações até 1000 ?g, mas nenhuma atividade foi detectada. / Abstract: Acacia longifolia (Andr.) Willd., is a shrub, (3-4 m in height). Originally from Australia east-tropical region, it is cultivated to firm dunes in steep ground. Acacia longifolia (Andr.) Willd. was investigated to evaluating anti-microbial activities and to identify flavonoids in its flowers. Three flavonoids were isolated by chromatographics means from the ethyl acetate fraction. The flavonoids were identified by spectral analysis and physical-chemical properties given Naringenin, a flavanone and two of its glycosides, 5-13-D-galactosil-naringenin and 5-f3-D-glucosil-naringenin. Using an HPLC system, the isolated flavonoids were quantified in the plant material, giving minimal values of 0,582 % (w/w) for 5-f3-D-galactosil-naringenin, 0,2 % (w/w) for 5- 13-D-glucosil-naringenin and 0,018 % (w/w) for naringenin. At the concentration of 500 ppm the ethyl acetate fraction showed a remarkable anti-fungi activity inhibiting 30% of the micelial growing from Rhizoctonia sp .. lt also inhibit the micelial growing of Colletotrichum acutatum (15,9%) and Fusarium oxysporum (10,5%). The crude ethanolic extract, the dicloromethane and the ethyl acetate fractions were tested againt strains of Staphylococcus aureus, S. epidermidis and Escherichia coli at concentrations up to 1000 ?g giving no activity.

Memoria para optar al Título Profesional de Ingeniero Agrónomo Mención Producción Animal / El matorral de Acacia caven (espinal), característico del secano interior de la zona central de Chile, se desarrolla en las zonas donde las precipitaciones son escasas y frecuentemente es eliminado en zonas de agricultura de tipo extensiva, no permitiendo su recuperación. Con el propósito de contribuir al conocimiento y un mejor aprovechamiento productivo de esta formación vegetacional, se midió la respuesta de la composición botánica y de la materia seca de la pradera anual mediterránea en relación al sombreamiento parcial de los espinos, según diámetro de copa, durante el día. El estudio se desarrolló en el área de secano de la Región Metropolitana (33º 29`S y 70º 52`O). Se utilizaron 15 espinos de características similares, según altura y diámetro, distribuidos en 3 tratamientos: arboles grandes, medianos y pequeños, describiendo el movimiento de la sombra proyectada por los espinos durante el día y se midió la composición botánica y materia seca de la pradera que se desarrolla bajo su influencia durante el periodo de crecimiento del pastizal (abril – noviembre). La diferencia en altura y diámetro de copa de los espinos no influye en la composición botánica de la pradera, sin embargo se presentaron diferencias en cuanto a la distribución de los géneros y especies presentes en el área de influencia de sombra. El promedio de M.S. bajo condiciones de sombra aumenta en un 13% para el tratamiento de espinos chicos y aumenta un 29% para espinos medianos y grandes, respecto de áreas sin influencia de sombra. También las horas de sombra acumuladas durante el día, como la hora del día en que se produce el sombreamiento influyó significativamente en la distribución de los géneros y especies de la pradera. / The Acacia caven (Mol.) thicket, characteristically found in the inner range of Chile’s central zone, develops in zones where precipitation is scarce and it is often eliminated in localities with extensive farming, not allowing its restoration. In order to contribute to knowledge and for a better productive utilization of this vegetational formation, measurements were made of the response of the botanical composition and dry matter of the annual Mediterranean pasture to the partial shade it gets from A. cavens (Mol.) trees (‘espinos’) during the day and for different canopy diameters. This study was conducted in the range area of the Metropolitan Region (33º29’ S. and 70º52’ W.) Fifteen ‘espinos’ with similar characteristics, according to height and canopy diameter, were used. They were allotted into three treatments: large, medium and small. The movement of the shade projected by the ‘espinos’ during the day was described and the botanical composition and dry matter of the pasture developed under their influence during the growth period (April – November) of the pasture were measured. The difference in height and canopy diameter of the ‘espinos’ did not affect the pasture’s botanical composition, even though differences occurred in the distribution of genera and species in the shadow’s area of influence. Larger shadow areas resulted in increased dry matter production, being 13% greater in small trees and 29% greater in medium-size and big trees. Besides, both the shadow hours accumulated during the day and the time when shading took place significantly influenced the distribution of genera and species in the pasture.