O Brasil é o país que possui o maior rebanho bovino comercial do mundo, e o balanço de exportações de couro vem demonstrando ascensão no número de metros quadrados de couros exportados. No processo produtivo, a etapa de curtimento é de extrema importância para transformar a pele bovina em couros, tornando-a resistente ao ataque de microorganismos, além de conferir enchimento e garantir maior estabilidade hidrotérmica do material. O crescente apelo ambiental pela utilização de materiais renováveis na indústria levou aos taninos vegetais desempenharem papéis importantes como compostos curtentes na indústria coureira. Os taninos são estruturas fenólicas complexas, existindo uma quantidade considerável de parâmetros químicos que podem ser mensurados através de diversas técnicas analíticas. Por outro lado, para os couros, também existem ensaios empregados no produto final, cujo desempenho pode depender do material curtente utilizado. No presente estudo, foram empregados cinco tipos de taninos de maior uso na indústria coureira para avaliação de parâmetros químicos e posterior associação com propriedades nos couros: tanino de acácia, quebracho, castanheiro, mirabolano e tara. Inicialmente, foi realizada uma revisão bibliográfica, a fim de determinar propriedades químicas de maior relevância a serem mensuradas nos taninos no contexto de sua utilização como agentes curtentes. Nesse sentido, elencaram-se os ensaios de determinação de tanantes totais, não-tanantes, sólidos insolúveis, sólidos solúveis, sólidos totais, fenóis totais e massa molecular média para os taninos. Os parâmetros de percentual de sólidos insolúveis, sólidos solúveis não-tanantes e tanantes totais distinguiram bem os grupos de taninos que atravessaram dos que não atravessaram o couro. Assim, pela análise de insolúveis ser a mais simples e direta delas, recomendar-se-ia o seu uso para definir uma faixa de corte para distinguir o desempenho dos taninos no curtimento. A análise de FTIR-UATR foi útil na caracterização e distinção dos taninos nas famílias dos hidrolisáveis e condensados. Os ensaios de temperatura de retração e distensão da flor nos couros também mostraram associação com o atravessamento dos taninos nas peles durante o curtimento. Por fim, a diferença total de cor após exposição à luz UV também foi avaliada para os couros curtidos com os taninos vegetais, sendo que os taninos hidrolisáveis apresentaram uma menor diferença de cor em relação aos condensados. / Brazil is the country with the largest commercial cattle herd in the world, and the balance of exports of leather has shown a rise in the number of square meters of exported leather. In the production process, the tanning step is extremely important to transform the skin into leather, making it resistant to the attack by microorganisms, as well as providing filling and assuring greater hydrothermal stability of the material. The increasing environmental approach for the use of renewable materials in the industry has led to vegetable tannins an important role as tanning compounds in the leather industry. Tannins are complex phenolic structures and there are a considerable amount of chemical parameters that can be measured through various analytical techniques to characterize them. On the other hand, for hides, there are also tests used in the final product, whose performance may depend on the tanning material used. In the present study, five types of tannins highly used in the tanning industry were used for the evaluation of their chemical parameters and later correlation with properties in hides: Black Wattle (Acacia mearnsii), Quebracho (Schinopsis lorentzii), Chestnut (Castanea sativa), Tara (Caesalpinia spinosa) and myrabolan (Terminalia chebula). Initially, a bibliographical review was carried out to determine the most relevant chemical properties to be measured in the tannins in the context of their use as tanning agents. In this context, the assays for the determination of total tannin polyphenols, non-tannin polyphenols, insoluble solids, soluble solids, total solids, total phenols and average molecular weight for tannins were performed. FTIR-UATR analysis was useful in characterizing and distinguishing tannins in their families of hydrolysates and condensates. The Mann-Whitney-U test showed that the insoluble solids, non-tannin polyphenols, soluble solids and total tannin polyphenols percentage distinguished well the groups of tannins that crossed the hide from those that didn´t. Hence, once the analysis of insoluble solids is the simplest and the most direct of them, it would be recommended to use this parameter to define a cutting range to distinguish the performance of tannins in leather tanning. The shrinkage temperature and distension tests in the leather also showed association with the leather cross-sectional results during tanning baths. Finally, the total color difference after exposure to UV light was also evaluated for the tanned hides with the vegetable tannins, and the hydrolysable tannins presented a smaller color difference or greater light fastness in comparison to the condensates.

O glyphosate é um dos herbicidas mais utilizados no mundo, pelo seu amplo espectro de ação, em espécies arbóreas, entretanto, pouco se sabe sobre a sua atuação nessas espécies. O objetivo desta pesquisa foi avaliar as alterações fisiológicas, bioquímicas e morfológicas do glyphosate em Acacia mangium. O experimento foi realizado em condições de campo. As plantas jovens de Acacia Mangium receberam 5 tratamentos correspondentes a doses do herbicida (0, 180, 360, 540 e 720 g.e.a.L-1 de glyphosate) em 6 repetições. No primeiro experimento,foi avaliado o crescimento e aspectos fisiológicos das plantas sob estresse oxidativo. Onde foram avaliadas as variáveis: Incremento em diâmetro, incremento em altura, massa seca do caule, folhas e raiz, intoxicação e também a assimilação líquida de carbono, condutância estomática, transpiração, eficiência do uso da água e eficiência da rubisco. No segundo experimento, avaliou-se as alterações bioquímicas em plantas jovens de Acacia mangium, sob estresse oxidativo. Para tanto, foi avaliado a atividade das enzimas antioxidantes: Ascorbato de peroxidase e superoxido dismutase. O glyphosate afeta a Acacia a partir da dose de 360 g.e.a.L-1 tanto fisiologicamente quanto morfologicamente. Os incrementos foram reduzindo de acordo com o aumento das doses. Em relação a assimilação líquida, as doses de 540 e 720 g.e.a.L-1 foram reduzidas aos 6, 12,18 DAA, se estabilizando a partir dos 24 dias de avaliação. As respostas das enzimas oxidativas ao estresse oxidativo foram variáveis. A enzima superóxido dismutase (SOD) apresentou um aumento na dose de 180 g.e.a.L-1 havendo decréscimo com o aumento das concentrações testadas. Para a Ascorbato de peroxidase (APX), mantiveram atividade semelhante nas duas avaliações, com um aumento continuo de acordo com o aumento das doses. / Glyphosate is one of the most widely used herbicides in the world due to its broad spectrum of action on tree species, but little is known about its performance in these species. The objective of this research was to evaluate the physiological, biochemical and morphological alterations of glyphosate in Acacia mangium. The experiment was carried out under field conditions. The young plants of Acacia Mangium received 5 treatments corresponding to doses of the herbicide (0, 180, 360, 540 and 720 g.e.a.L-1 of glyphosate) in 6 replicates. In the first experiment, the growth and physiological aspects of the plants under oxidative stress were evaluated. The following variables were evaluated: increase in diameter, height increase, stem dry mass, leaves and root, intoxication and also net carbon assimilation, stomatal conductance, transpiration, water use efficiency and rubisco efficiency. In the second experiment, the biochemical alterations were evaluated in young plants of Acacia mangium, under oxidative stress. For that, the activity of the antioxidant enzymes: peroxidase ascorbate and superoxide dismutase was evaluated. Glyphosate affects Acacia from the 360 g.e.a.L-1 dose both physiologically and morphologically. The increments were reduced as the doses increased. Regarding the net assimilation, the doses of 540 and 720 g.e.a.L-1 were reduced to 6, 12,18 DAA, stabilizing from the 24 days of evaluation. The responses of oxidative enzymes to oxidative stress were variable. The enzyme superoxide dismutase (SOD) showed a dose increase of 180 g.e.a.L-1, decreasing with increasing concentrations tested. For the peroxidase Ascorbate (APX), they maintained similar activity in both evaluations, with a continuous increase according to the increase of the doses.

Raramente plantações de eucalipto respondem à adubação nitrogenada. Contudo, por se tratar de povoamentos monoespecíficos, com baixa capacidade de fixação de N, depois de algumas rotações de cultivo a probabilidade de resposta a este nutriente aumenta, devido ao esgotamento das reservas naturais de nitrogênio do solo acumuladas no ecossistema anterior. O presente estudo teve como objetivos avaliar i) o crescimento, o desenvolvimento de raízes finas de Eucalyptus grandis e de Acacia mangium em povoamentos monoespecíficos e mistos; ii) a nodulação da A. mangium nestes povoamentos. As árvores foram plantadas em maio de 2003 no espaçamento 3m x 3m. O delineamento experimental foi o de blocos completamente aleatorizados (4 blocos), sendo avaliados 3 tratamentos: povoamentos monoespecíficos de E. grandis e A. mangium e um povoamento em que essas espécies foram consorciadas (1100 plantas por ha de E. grandis e 550 árvores por ha de A. mangium). Quando consorciada, a A. mangium foi plantada no meio da distância entre as árvores de E. grandis na mesma linha de plantio. Foram amostradas raízes finas vivas (≤3 mm) em 5-16 posições (dependendo do tratamento), de uma árvore de área basal média em doze parcelas (3 tratamentos x 4 blocos), até 1 m de profundidade aos 6 e 12 meses pós-plantio e até 2 m de profundidade aos 18 e 30 meses pós-plantio, por meio de uma sonda de aço com 4,5 cm de diâmetro interno. O E. grandis foi diferente da A. mangium quanto ao desenvolvimento radicular nos diferentes períodos de amostragem, principalmente na camada superficial do solo (0-10 cm). No povoamento misto, aos 30 meses pós-plantio, o E. grandis foi 64% maior em altura do que a A. mangium e 75% maior em área basal, produzindo 94% mais biomassa do que esta leguminosa. A assimetria do crescimento radicular foi elevada entre as espécies, reflexo da grande competição por luz na parte aérea. Não houve clara estratificação de exploração das camadas do solo pelo sistema radicular das espécies. O E. grandis apresentou maior exploração radicular em todas as camadas do solo, fazendo com que o desenvolvimento radicular da A. mangium ficasse restrito a proximidade da árvore. O elevado grau de assimetria no desenvolvimento radicular entre as espécies resultou, aos 30 meses, na camada 0-10 cm, numa diferença de 91% na densidade de raízes finas (drf) entre as espécies. A nodulação foi sensível a competição com o E. grandis, aparentemente, devido à variação de umidade e temperatura sazonal. Aos 18 meses, no povoamento monoespecífico, houve tendência de maior densidade de nódulos na linha de plantio, camada 0-10 cm. Aos 30 meses os nódulos foram encontrados próximos às árvores. No misto, aos 18 e 30 meses ocorreu diminuição da densidade de nódulos na camada 10-30 cm e aumento entre 30 e 50 cm. / Eucalypts plantations rarely answer to the nitrogen fertlization. However, for being of monospecific stands, with low capacity of N fixation, after some cultivation rotations the answer probability to this nutritious one increases, due to the exhaustion of the natural reservations nitrogen of the soil accumulated in previous ecosystem. The present study had as objectives to evaluate i) the growth, the development of Eucalyptus grandis and Acacia mangium fine-root in monospecific and mixed stands; ii) the A. mangium nodulation in these stands. The trees were planted in may of 2003 in the spacing 3m x 3m. The experimental design was it of completely randomized blocks (4 blocks), between assessed 3 treatments: Monospecific stands of E. grandis and A. mangium and a stand in that those species were mixed (1100 plants for ha of E. grandis and 550 trees for ha of A. mangium). When mixed, to A. mangium was planted in the middle of the distance among the trees of E. grandis in the same plantation line. They were sampling live fine-root (≤ 3 mm) in 5-16 positions (depending on the treatment), of a tree of medium basal area in twelve portions (3 treatments x 4 blocks), until 1 m of depth to the 6 and 12 months powder-plantation and until 2 m of depth to the 18 and 30 months powder-plantation, by means of a sledgehammer with 4,5 cm of internal diameter. The E. grandis was different from the A. magium with relationship to the roots development in the different sampling periods, mainly in the superficial layer of the soil (0-10 cm). In the mixed stand, between 29 and 30 months after plantation, E. grandis was 64% larger in height than at A. mangium and 75% larger in basal area, producing 94% more biomass than this leguminous. The asymmetry of the root growth was elevated between the species, reflex of the great competition for light in the aerial part. There was not clear stratification of exploration of the layers of the soil for the roots system of the species. The E. grandis presented larger roots exploration radicular in all the layers of the soil, doing with that the roots development of the A. mangium was restricted in the proximity of the tree. The high asymmetry degree in the roots development between the species, resulted to the 30 months in the layer 0-10 cm, a difference of 91% in the density of fine roots (dfr) between the species. The nodulation was sensitive the competition with the E. grandis , seemingly, due to the humidity variation and seasonal temperature. To the 18 months, in the monospecific stands, there was tendency of larger density of nodules in the plantation line, layer 0-10 cm. To the 30 months the nodules were found close to the trees. In the mixed, to the 18 and 30 months it happened decrease of the density of nodules in the layer 10-30 cm and increase between 30 and 50 cm.

Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2014-07-02T19:15:47Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_ProspeccaoMoleculasQuimicas.pdf: 1625380 bytes, checksum: d9341efbc92b6928b40c9eb73e86b35e (MD5) / Approved for entry into archive by Ana Rosa Silva (arosa@ufpa.br) on 2014-07-17T14:04:09Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_ProspeccaoMoleculasQuimicas.pdf: 1625380 bytes, checksum: d9341efbc92b6928b40c9eb73e86b35e (MD5) / Made available in DSpace on 2014-07-17T14:04:09Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_ProspeccaoMoleculasQuimicas.pdf: 1625380 bytes, checksum: d9341efbc92b6928b40c9eb73e86b35e (MD5) Previous issue date: 2009 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Muito se tem estudado sobre o potencial que algumas plantas têm de inibir o desenvolvimento de outras plantas. Em busca de alternativas para reduzir a dependência de herbicidas sintéticos, diminuindo os danos ambientais e prejuízos à saúde humana e procurando alternativas à resistência aos herbicidas do mercado, os compostos naturais oferecem excelentes perspectivas. Este trabalho isola, identifica as estruturas e caracteriza a atividade alelopática de duas substâncias químicas produzidas pela espécie Acacia mangium. Para isso, procede-se com solução hidroalcoólica (7:3) extração exaustiva das folhas secas caídas, folhas verdes, raízes e sementes dessa espécie, passando-se pela recuperação do etanol (evaporador rotativo) e liofilização dos extratos para a desidratação e obtenção do extrato bruto hidroalcoólico (EBHA). Para identificar qual parte da planta possui maior potencial alelopático, é preparado um bioensaio com a utilização de solução hidroalcoólica (7:1) de cada EBHA em concentração de 1%. É determinado o potencial inibitório sobre a germinação, desenvolvimento do hipocótilo e desenvolvimento da radícula das sementes das plantas daninhas malícia (Mimosa pudica), mata-pasto (Senna alata) e puerária (Pueraria phaseoloides). 10 g do EBHA das folhas caídas são submetidas à CCVU para separação das substâncias, a partir do qual são obtidas quatro reuniões de substâncias semelhantes. Três delas são refracionadas em colunas menores (R1’, R2- R3’, R4’) e da coluna R1’ são isoladas as substâncias Lupenona e Lupeol. Nos bioensaios com os extratos, o das folhas secas apresenta as inibições mais acentuadas, notadamente sobre a germinação (99%). Nesta característica, mata-pasto é a espécie de menor sensibilidade, com inibições abaixo de 12%. São realizados bioensaios com as substâncias isoladas e em par (solubilizadas em clorofórmio), na concentração de 140 ppm, sobre as sementes de Mimosa pudica e Senna obtusifolia. Para a germinação das sementes, as substâncias em todos os tratamentos não evidenciam qualquer efeito. Para o desenvolvimento da radícula, ambas as substâncias, isoladamente, promovem inibições em torno de 40% sobre duas espécies de plantas daninhas, enquanto que em par, observa-se que há antagonismo entre as substâncias, já que os resultados são inferiores, ficando ao redor de 30%. Com relação ao crescimento do hipocótilo a inibição em todos os tratamentos fica em torno de 15% e não há diferença significativa entre os resultados. É testado também o efeito do pH (3,0 e 9,0) na atividade alelopática das substâncias, isoladas e em par, sobre a germinação das sementes de malícia e observa-se que há interação para os fatores pH e germinação, havendo maior atividade inibitória da lupenona em condições ácidas e do lupeol em condições alcalinas. Não há efeito aditivo ou negativo quando da associação das substâncias. É realizada também análise por HPLC nos extratos brutos hidroalcoólicos de três partes da planta Acacia mangium para a detecção dos flavonóides catequina e epicatequina (substâncias com comprovado efeito alelopático), sendo que a epicatequina é a substância com absorção para os espetros selecionados, mostrando que esta substância pode ter contribuído para os resultados expressivos observados nos primeiros bioensaios com os extratos brutos das partes das plantas. / Much has been studied on the potential that some plants have to inhibit the development of other plants. In search of alternatives to reduce dependence on synthetic herbicides, reducing environmental damage and harm to human health and seeking alternatives to herbicide resistance to the market, the natural compounds offer excellent prospects. This study isolates, identify the structures and features the allelopathic activity of two chemicals produced by the species Acacia mangium. For this, it is with water-alcohol solution (7:3) exhaustive extraction of fallen leaves, green leaves, roots and seeds of this species, passing by the recovery of ethanol (rotary evaporator) and lyophilization of the extracts for dehydration and obtaining the hydroalcoholic crude extract (HCE). To identify which part of the plant has higher allelopathic potential, a bioassay is prepared with the use of water-alcohol solution (7:1) of each HCE concentration of 1%. We determined the inhibitory potential on the germination, development of hypocotyl and radicle of the weed seeds Mimosa pudica, Senna alata e Pueraria phaseoloides. 10 g of HCE of fallen leaves are subjected to CCVU for separation of substances, from which are obtained four meetings similar substances. Three of them are lower refractive in columns (R1 ', R2, R3', R4 ') and column R1' are isolated substances lupenona and lupeol. In bioassays with extracts, the dried leaves shows the most pronounced inhibitions, especially on the germination (99%). In this feature, is the Senna alata species of lesser sensitivity, with losses below 12%. Bioassays are performed with the substances isolated and par (solution in chloroform), the concentration of 140 ppm on the seeds of Mimosa pudica and Senna obtusifolia. For seed germination, the substances in all treatments did not show any effect. For the development of the radicle, the two substances alone, promote inhibition of around 40% on two species of weeds, while in addition, it appears that there is antagonism between the substances, since the results are below, with the around 30%. With respect aocrescimento of hypocotyl inhibition in all treatments is around 15% and no significant difference between the results. We also tested the effect of pH (3.0 and 9.0) in the allelopathic activity of the substances, alone and in pairs, on the germination of seeds of malice and observes that there is interaction for the factors pH and germination, with greater inhibitory activity of lupenona under acidic and alkaline conditions in lupeol. There is additive or negative effect when the combination of substances. It is also performed by HPLC analysis on crude extracts water from three parts of the plant Acacia mangium for the detection of the flavonoids catechin and epicatechin (substances with proven allelopathic effect), with epicatechin is the substance with the absorption spectrum for selected, showing that substance may have contributed to the significant results observed in the first bioassays with crude extracts of plant parts.

Submitted by Sandro Camargo (sandro.camargo@unipampa.edu.br) on 2015-05-07T23:21:07Z No. of bitstreams: 1 111010005.pdf: 731177 bytes, checksum: 3340e7380683d381f6e08622380ed7db (MD5) / Made available in DSpace on 2015-05-07T23:21:07Z (GMT). No. of bitstreams: 1 111010005.pdf: 731177 bytes, checksum: 3340e7380683d381f6e08622380ed7db (MD5) Previous issue date: 2012-12-12 / A região do Pampa Gaúcho está passando por modificação do tipo de uso do solo, com a inserção da silvicultura em solos de pastagens ou agricultura. No entanto, pouco se conhece sobre o impacto que tal mudança implica no fluxo dos Gases de Efeito Estufa (GEE) nessa região, especialmente em relação aos fluxos de metano (CH 4 ) e óxido nitroso (N 2 O) do solo. Este estudo teve como objetivo principal avaliar a inserção da silvicultura, com Acacia mearnsii De Wild e Eucalyptus saligna, em áreas de campo nativo e o seu efeito no fluxo CH 4 e N 2 O do solo, e determinar os principais fatores de solo que governam os fluxos destes gases. Dois experimentos foram realizados durante o período de um ano, em povoamentos de Acacia mearnsii De Wild avaliando quatro tratamentos: Acácia (AM), Acácia com retirada manual de serrapilheira (A-s), Acácia recém colhida (AC) e campo nativo (CN); e de Eucalyptus saligna avaliando cinco tratamentos: Eucalipto com quatro anos (E4), Eucalipto com quatro anos com retirada manual da serrapilheira (E4-s), Eucalipto com dois anos (E2), Mata Nativa (MN) e Campo Nativo (CN), utilizando o campo nativo como tratamento de referência. As amostras de ar foram coletadas quinzenalmente pelo método de câmaras estáticas e os teores dos gases foram determinados por cromatografia gasosa. Em cada evento de amostragem de ar, foram avaliados a umidade e os teores de nitrogênio mineral do solo, coletada a serrapilheira e monitorada a temperatura do solo e do ar dentro da câmara. A inserção tanto do eucalipto como de acácia não alterou significativamente os fluxos de CH 4 e N 2 O do solo em relação ao campo nativo adjacente a cada floresta. Os fluxos de N 2 O foram geralmente baixos, com a maioria dos valores entre –5 e 30 μg N m -2 h -1 , provavelmente favorecidas pela baixa precipitação do período avaliado e dos baixos teores de nitrogênio mineral do solo. Houve predomínio de oxidação de CH 4 nos solos sob silvicultura no período avaliado, em magnitude similar ao campo nativo. O solo sob eucalipto com dois anos tendeu a emitir mais N 2 O do que com quatro anos. A colheita da acácia promoveu aumento da emissão de N 2 O, provavelmente decorrente da maior disponibilidade de nitrogênio mineral no solo para os processos de nitrificação e desnitrificação. Em relação ao CH 4 , a maior emissão coincidiu com os períodos de temperatura do solo mais elevada, o que é coerente com o aumento da atividade biológica, principalmente em áreas com menor cobertura vegetal. Os teores de carbono orgânico total (COT) e nitrogênio total (NT) do solo sob eucalipto e acácia não diferiram significativamente do campo nativo para a ampla maioria das camadas avaliadas. Somado aos baixos fluxos de CH 4 e N 2 O da silvicultura, o sequestro de carbono via biomassa vegetal e produtos madeireiros sugerem que a mudança de uso do solo com inserção de silvicultura seja uma opção efetiva para a mitigação dos GEE e aumento do sequestro de carbono em áreas da região do Pampa Gaúcho. / The soil use in the region of the Pampa Gaúcho has been modified by of forestation in soils previously used for agriculture or grazing. However, little is known about the impact of this change on greenhouse gases (GHG) fluxes in the soil in that region, mainly regarded to the methane (CH 4 ) and nitrous oxide (N 2 O). This study aimed to evaluate the effect of the conversion of native grassland to forestry, with Acacia mearnsii De Wild and Eucalyptus saligna, in the Pampa Gaúcho on the soil CH 4 and N 2 O fluxes, besides determining the soil variables that govern these fluxes. Two experiments were conducted for one year, in plantations of Acacia mearnsii De Wild evaluating four treatments: Acacia (AM), Acacia with manual litter removal (A-s), Acacia recently harvested (AH) and native grassland (NG); and Eucalyptus saligna evaluating five treatments: four–year Eucalyptus plantation (E4), four– year Eucalyptus plantation with manual litter removal (E4-l), two–year Eucalyptus plantation (E2), Native forest (NF) and Native grassland (NG), using the native grassland as reference treatment. The air samples were taken biweekly by the method of static chambers and gas concentrations were determined by gas chromatography. In each sampling event, we evaluated the soil moisture and mineral nitrogen content, deposition of litter and monitored the soil and chamber air temperature. The forestation with both eucalyptus and acacia did not alter significantly the soils fluxes of CH 4 and N 2 O in comparison to the native grassland adjacent to each forest. The N 2 O flux are generally low, with most values ranging from –5 to 30 μg N m -2 h -1 , probably favoured by the low rainfall and soil mineral nitrogen levels during the evaluated period. Similarly magnitude to the soil under native grassland, CH 4 oxidation predominated in forested soils in the period of the experiment. The soil with two-year old eucalyptus plantation tended to emit more N 2 O than the four-year plantation. The harvest of acacia increased the soil N 2 O emission, likely due to the larger availability of mineral N in the soil for the nitrification and denitrification processes. With respect to CH 4 , the largest emission coincided with periods of higher soil temperature, which is coherent herewith increased of the biological activity, especially in areas with less vegetation cover. The contents of total organic carbon (TOC) and total nitrogen (TN) in soils with eucalyptus and acacia were not significantly different from those observed in native grassland soil for most layers. The low CH 4 and N 2 O emissions from forestry added to the carbon sequestration in the plant biomass and wood products suggests that the change of land use for forestation is an effective option for mitigating the GHG emissions and for increasing the carbon sequestration in areas such as the Pampa Gaúcho.

Thesis (M.Sc. (Agriculture)) --University of Limpopo, 2006 / Two experiments were carried out to determine the effect of the level of Acacia nilotica leaf meal supplementation plus 23 g polyethylene glycol 4000 on diet intake, digestibility, and growth rate of indigenous Pedi goats fed ad libitum Buffalo grass, Buchloe dactyloides, hay. The first experiment lasted for 37 days, with the first 30 days being for adaptation and the last 7 days being for collection. Twenty yearling male Pedi goats weighing 22 ± 0.5 kg live weight were allocated to 4 treatments in a 2 x 2 Factorial arrangement in a Completely Randomised Design. Acacia nilotica leaf meal contained 120 g crude protein per kg DM, indicating its potential as a browse source for ruminants. It, also, contained high amounts of total phenolics (2.04 % DM) and low amounts of condensed tannins, both extracted (0.37 % DM) and unextracted (1.83 % DM). Increasing the level of Acacia nilotica leaf meal supplementation to 120 g increased (P<0.05) crude protein intake (38 g/kg DM) when compared to 80 g supplementation (34 g/kg DM). Supplementation with 23 g PEG 4000 increased (P<0.05) the crude protein intake where goats were supplemented with 120 g of A. nilotica leaf meal. However, PEG 4000 supplementation did not have an effect (P>0.05) on intake when goats were supplemented with 80 g of Acacia nilotica leaf meal. Supplementation with 120 g of Acacia nilotica leaf meal increased (P<0.05) diet digestibility of DM (0.57), OM (0.60) and CP (0.71) by the goats. Similarly, supplementation with 23 g PEG 4000 increased (P<0.05) DM (0.65), OM (0.66) and v CP digestibilities (0.76) where goats were supplemented with 120 g of A. nilotica leaf meal. Polyethylene glycol 4000 also increased (P<0.05) diet CP digestibility where goats were supplemented with 80 g of Acacia nilotica leaf meal. However, 23 g PEG 4000 did not have a significant (P>0.05) effect on diet digestibility of DM and OM where goats were supplemented with 80 g of Acacia nilotica leaf meal. In vivo NDF and ADF digestibility were not affected by the treatments. Level of Acacia nilotica leaf meal supplementation plus 23 g of PEG 4000 had a significant (P<0.05) effect on the daily live weight change of the goats. The effect was higher where goats were supplemented with 120 g of A. nilotica leaf meal when compared to 80 g supplementation. Blood urea concentrations were improved (P<0.05) by level of A. nilotica supplementation and PEG supplementation. It is concluded that PEG 4000 has the potential to improve the feeding value of Acacia nilotica leaf meal and can, therefore, be used in the feeding systems for ruminant animals. The second experiment determined the effect of A. nilotica leaf meal supplementation and PEG 4000 supplementation on in vitro diet digestibility. Level of Acacia nilotica leaf meal supplementation plus 23 g PEG supplementation improved (P<0.05) in vitro diet DM, OM and CP digestibilities where 120 g Acacia nilotica leaf meal was supplemented. Similarly, 23 g PEG 4000 supplementation also improved (P<0.05) in vitro diet CP digestibility where 80 g Acacia nilotica leaf meal was supplemented. However, level of A. nilotica supplementation plus PEG 4000 supplementation had no vi effect (P>0.05) on in vitro NDF and ADF digestibilities. In vivo diet DM, OM and CP digestibilities were positively and significantly (P<0.05) correlated with in vitro diet DM, OM and CP digestibilities. It is, therefore, concluded that in vitro diet DM, OM and CP digestibilities have good capacity to predict in vivo diet DM, OM and CP digestibilities. / National Research Foundation. Working Solutions International

Acacia saligna is a native species complex with a widespread natural distribution throughout the south west of Western Australia. It is being developed as an agroforestry crop to produce low value, bulk biomass products in the low rainfall agricultural areas of southern Australia. This thesis develops knowledge to assist the domestication and breeding program of A. saligna as an agroforestry cultivar. It also furthers development of a risk management plan for utilisation of the Acacia saligna species complex. Highly informative microsatellite markers for A. saligna were developed for use in mating system studies, paternity analysis and in the development of a diagnostic tool for the identification of individuals and populations at the subspecific level. Microsatellites developed in other Acacia species were also screened for utility in A. saligna. A high level of outcrossing (mean multilocus outcrossing rate of 0.98) and little true selfing was found for a planted stand of A. saligna subspecies saligna. Paternity analysis indicated heterogeneity in pollen clouds experienced by maternal trees and an essentially random pattern of mating within the stand. Inter-subspecific pollen immigration into the stand from trees of subspecies lindleyi was detected for 14% of progeny analysed and occurred over distances greater than 1500 m. Extensive intra-subspecific pollen-mediated gene flow is maintained between remnant natural populations of A. saligna subspecies lindleyi, and a high level of inter-subspecific pollen immigration from trees in the planted stand of A. saligna subspecies saligna was detected in remnant populations of subspecies lindleyi (32% of analysed progeny) occurring over distances greater than 1500 m. Polymorphic microsatellite markers used to investigate genetic structuring within A. saligna revealed a high level of genetic divergence between subspecific entities congruent with a taxonomic reclassification of the species complex. Selected microsatellite markers also proved suitable for use as a rapid diagnostic tool that can be used to characterise populations into one of the proposed subspecies of A. saligna with high probability. These results indicate that high levels of outcrossing and essentially random patterns of mating that maintain genetic diversity in seed crops should be achievable with the suitable management of seed production stands of A. saligna. Appropriate management techniques that limit genetic contamination into seed production stands will need to be employed to achieve this goal. Management techniques will also be required to minimise the risk of genetic contamination from stands planted for agroforestry purposes into remnant natural populations. Isolation distances greater than 1500 m between genetically divergent agroforestry crops and natural populations are suggested in both cases and key areas of further research are suggested. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1336865 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2008

Thesis (M. Environmental Science (Ecological Remediation and Sustainable Utilisation))--North-West University, Potchefstroom Campus, 2007.

<p>The aim of the study was to quantify the extent of inorganic chemical pollution of the Franschhoek River and draw relationships between contaminants in water, sediment and plants. The invasive Acacia mearnsii and Salix babylonica and indigenous Brabejum stellatifolium species were chosen as biomonitors due to their wide spread distribution along the river and their apparent ability to accumulate heavy metals. The sites chosen allowed for comparison of the river quality upstream with that of the river further down stream as it meandered through residential, agricultural and recreational areas, until it joined with the Berg River further downstream. The general aim of the study was to assess the degree of inorganic pollution in the Franschhoek River to evaluate its contribution to pollution of the Berg River, of which it is an important tributary. Also understanding the sources of the pollution would contribute to the ability to reduce pollution.</p>

Nous nous sommes intéressés à la compréhension des mécanismes régissant la symbiose Rhizobium-Acacia dans les conditions de stress salin. Les lipopolysaccharides jouent un rôle important dans les étapes de cette symbiose. Le but était de mettre en évidence les modifications pariétales de la bactérie en réponse au stress salin par l'étude de la structure des lipopolysaccharides des souches isolées du désert marocain tolérant NaCl 7%. Ainsi, une nouvelle méthode d'hydrolyse des lipopolysaccharides sensible, non destructive et compatible avec la spectrométrie de masse a été développée. En présence de stress salin, nous avons montré que la membrane externe devenait plus hydrophobe en augmentant l'acylation de la région lipidique ainsi qu'en réduisant la présence des molécules de LPSs à longues chaînes de sucres.Des essais d'évaluation de l'efficience et de l'infectivité des Rhizobia étudiés ont été mis en œuvre pour déterminer l'impact de ces modifications des LPSs sur la symbiose sous stress salin.