No contexto das mudanças climáticas, a sobrevivência e a produtividade das plantações de eucaliptos poderão ser afetadas. Assim, são necessárias pesquisas em nutrição florestal, como a avaliação do K e do Na e sua interação com a disponibilidade hídrica com o crescimento e propriedades do lenho de eucaliptos. Em experimento instalado, em 20 de junho de 2010 de tipo \"Split-plot\", foram avaliadas as árvores de Eucalyptus grandis submetidas a dois regimes hídricos (100% e 63%) e três tipos de fertilização (K, Na e controle). O diâmetro do tronco (cada 15 dias, com dendrômetros) e a altura total (cada 6 meses) das árvores foram mensurados no período do 40º ao 61º mês. A umidade do solo foi analisada semanalmente e a precipitação e temperatura diariamente. Foram analisadas as propriedades do lenho de 48 árvores, no 47º mês, por amostragem destrutiva, avaliando-se a sua densidade aparente, densidade básica, estrutura anatômica e proporção cerne/alburno. Os resultados mostraram que a precipitação influenciou significativamente o crescimento das árvores, seguindo-se a temperatura mínima e a umidade do solo. O K e o Na mostraram interação com a precipitação, (i) no período seco, com a redução do incremento do tronco das árvores com o Na e a sua paralisação com o K, (ii) no período chuvoso, com o aumento do incremento em diâmetro e altura do tronco, em relação ao controle. O Na em relação ao K resultou em menor crescimento das árvores de eucalipto. Com a exclusão de 37% da chuva houve efeito negativo nas árvores com K; no tratamento controle e com aplicação de Na a exclusão não mostrou efeito significativo até o 58º mês. Em relação à (i) densidade do lenho das árvores- ocorreu a sua diminuição com K e Na (menor com Na), e incremento com a menor disponibilidade hídrica; K não diminuiu a densidade sob maior disponibilidade hídrica; (ii) anatomia do lenho- observaram-se vasos de maior diâmetro e menor frequência com K e Na (maior com K); as fibras apresentaram variação significativa com Na (com fibras mais longas e largas com menor espessura da parede); a menor disponibilidade hídrica resultante da exclusão de 37% da chuva não afetou aos vasos e fibras; (iii) relação cerne/alburno- o K e Na promoveram a formação de maior proporção de cerne em relação às árvores do tratamento controle, sem influência significativa da exclusão parcial de chuva. Relações entre anatomia e densidade do lenho mostraram que mudanças nas dimensões das fibras foram acompanhadas de mudanças na densidade do lenho; e maior taxa de crescimento nem sempre se relaciona com a diminuição da densidade do lenho. Os resultados indicaram que a perda de características desejáveis na densidade, fibras e proporção de alburno, com a adição de K ou Na (principalmente Na) na adubação básica, são altamente compensados pela maior produção de lenho, no entanto em regiões mais áridas e com maior risco de seca prolongada, potássio e sódio podem agravar o déficit hídrico. / In the context of climate change, survival and productivity of eucalyptus plantations may be affected. Thus, research is needed on nutrition and forest ecophysiology, such as the evaluation of K and Na and their interaction with water availability on the growth and wood properties of eucalyptus. In a split-plot type, experiment installed on June 20, 2010 we evaluated Eucalyptus grandis trees submitted to two water regimes (100% and 63%) and three fertilizer supplies (K, Na and control). The stem diameter was measured every 15 days with dendrometers and total height, every 6 months in the period from 40th to 61st month. Soil moisture was analyzed weekly and precipitation and temperature daily. The wood properties of 48 trees were analyzed after 47 months, by destructive sampling, evaluating their apparent density, specific gravity, anatomical structure and heartwood/sapwood proportion. The results showed that precipitation significantly influenced the growth of the trees, followed by the minimum temperature and soil moisture. K and Na showed interaction with precipitation, (i) in the dry season, by reducing the growth of the tree trunks with Na and its stoppage with K, (ii) during the rainy season, with increasing growth in diameter and height of the trunk, compared with the control. The Na, as compared to K, resulted in lower growth of the eucalyptus trees. With the artificial exclusion of 37% of throughfall there was a negative effect on the growth of trees fertilized with K; but in the control and Na treatment the rainfall exclusion showed no significant effect until 58º month. In relation to (i) density of the wood of trees, there was a decrease in K and Na (lower with Na), and an increase with lower water availability; although the K did not reduce the density under higher water availability; (ii) wood anatomy- larger vessels with lower frequency were formed with K and Na supply (with higher K); the fibers showed significant variations with Na (longer and wider fibers with smaller wall thickness); and the lower water availability from the of 37% rainfall exclusion did not affect vessels and fibers; (iii) Heartwood/sapwood ratio; K and Na promoted the formation of larger proportion of heartwood in relation to the trees from the control treatment, and there was no significant influence of the partial rainfall exclusion. Relationships between anatomy and wood density showed that changes in fiber dimensions were accompanied by changes in the wood density; and the higher growth rate is not always associated with decreased wood density. The results indicate that the loss of desirable characteristics in density, fiber and proportion of sapwood, with the addition of K or Na (mainly Na) in the basic fertilization are highly compensated by the increased wood production, though in more arid regions with increased risk of prolonged drought, potassium and sodium can aggravate water deficit.

The measurement of plant water content is essential to assess stress and disturbance in forest plantations. Traditional techniques to assess plant water content are costly, time consuming and spatially restrictive. Remote sensing techniques offer the alternative of a non destructive and instantaneous method of assessing plant water content over large spatial scales where ground measurements would be impossible on a regular basis. The aim of this research was to assess the relationship between plant water content and reflectance data in Eucalyptus grandis forest stands in KwaZulu-Natal, South Africa. Field reflectance and first derivative reflectance data were correlated with plant water content. The first derivative reflectance performed better than the field reflectance data in estimating plant water content with high correlations in the visible and mid-infrared portions of the electromagnetic spectrum. Several reflectance indices were also tested to evaluate their effectiveness in estimating plant water content and were compared to the red edge position. The red edge position calculated from the first derivative reflectance and from the linear four-point interpolation method performed better than all the water indices tested. It was therefore concluded that the red edge position can be used in association with other water indices as a stable spectral parameter to estimate plant water content on hyperspectral data. The South African satellite SumbandilaSat is due for launch in the near future and it is essential to test the utility of this satellite in estimating plant water content, a study which has not been done before. The field reflectance data from this study was resampled to the SumbandilaSat band settings and was put into a neural network to test its potential in estimating plant water content. The integrated approach involving neural networks and the resampled field spectral data successfully predicted plant water content with a correlation coefficient of 0.74 and a root mean square error (RMSE) of 1.41 on an independent test dataset outperforming the traditional multiple regression method of estimation. The potential of the SumbandilaSat wavebands to estimate plant water content was tested using a sensitivity analysis. The results from the sensitivity analysis indicated that the xanthophyll, blue and near infrared wavebands are the three most important wavebands used by the neural network in estimating plant water content. It was therefore concluded that these three bands of the SumbandilaSat are essential for plant water estimation. In general this study showed the potential of up-scaling field spectral data to the SumbandilaSat, the second South African satellite scheduled for launch in the near future. / Thesis (M.Sc.) - University of KwaZulu-Natal, Pietermaritzburg, 2008.

Made available in DSpace on 2016-12-23T13:51:56Z (GMT). No. of bitstreams: 1 Rafael Leite Braz.pdf: 1782732 bytes, checksum: 28019d0f41458f1450d492fc581fa0d7 (MD5) Previous issue date: 2011-02-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Forest plantations in the Vale do Rio Doce in Minas Gerais have suffered damage caused by the action of wind, especially in areas of lowlands and in young stands. Studies to identify relationships between the susceptibility of trees of the wood properties are of great importance, allowing selection of clones more tolerant to wind action. Thus, the purpose of this study was to characterize the wood of trees of ten clones of the hybrid Eucalyptus urophylla x Eucalyptus grandis, 30 and 35 months of age, on the strength of the tree to fall and the anatomical, physical, mechanical and chemical characteristics of trees. The study site was in lowland regions, where trees are more vulnerable and prone to damage from winds with altitude near 250 m and with low intensity of the climatological winds and frequent occurrence of micro-atmospheric explosions. For this, the dendometric characteristics of the trees were measured and evaluated and strength tests of the tree to fall were done, simulating the effect of wind and a non-destructive method for the determination of longitudinal residual strain. In the laboratory sample of wood were prepared and then analyzed the quantitative anatomical parameters of wood, for the vessels and the morphology of the fibers, the density, the bending, the concentrations of extractives, lignin and holocellulose and calculated the growth stress. The conclusion is that the clone CNB017 showed the best results, especially in the testing of breaking strength, the physical and mechanical properties evaluated. For the chemical composition, the clones showed close values for the levels of extractive, lignin and holocellulose, serving only as indicative for the production and yield of cellulose. The endurance test and the mechanical and physical characteristics stood out as the most suitable parameters for the assessment and classification of clones susceptible to wind action, whereas the clones that showed the best results were common. However there is need to broaden the base information regarding the susceptibility of trees to wind / Plantios florestais na região do Vale do Rio Doce no Estado de Minas Gerais vêm sofrendo danos provocados devido a ação dos ventos, principalmente, nas regiões de baixadas e em povoamentos jovens. Estudos no sentido de identificar relações entre a susceptibilidade das árvores com as propriedades da madeira são de grande importância, possibilitando assim seleção de clones mais tolerantes à ação dos ventos. Assim, o objetivo do presente trabalho foi caracterizar o lenho de árvores de dez clones do híbrido Eucalyptus urophylla x Eucalyptus grandis, com 30 e 35 meses de idades, quanto à resistência das árvores à quebra e às características anatômicas, físicas, mecânicas e químicas. O local de estudo foi nas regiões de baixada, onde as árvores são mais vulneráveis e sujeitas aos danos provocados por ventos, com altitude próxima a 250 m, com baixa intensidade dos ventos climatológicos e grande ocorrência de micro-explosões atmosféricas. Para isso, foram mensuradas e avaliadas as características dendrométricas das árvores. Realizaram-se os testes de resistência das mesmas à quebra, simulando o efeito do vento e um método não destrutivo para a determinação da deformação residual longitudinal. Em condições de laboratório, as amostras de madeira foram preparadas e, em seguida, analisados os parâmetros anatômicos quantitativos da madeira, relativos aos vasos e à morfologia das fibras, a densidade básica, a flexão estática, os teores de extrativos, lignina e holocelulose e calculado as tensões de crescimento. Pôde-se concluir que o clone CNB017 foi o que apresentou os melhores resultados, principalmente, no teste de resistência à quebra, para as características físicas e mecânicas avaliadas. Para a composição química, os clones apresentaram valores próximos para os teores de extrativo, lignina e holocelulose, servindo apenas como indicativo para a produção e rendimento de celulose. O teste de resistência e as características mecânicas e físicas se destacaram como os parâmetros mais adequados para a avaliação e classificação dos clones susceptíveis à ação dos ventos, visto que os clones que apresentaram os melhores resultados foram comuns. Entretanto, há necessidade de ampliar a base de informações a respeito da susceptibilidade das árvores ao vento

No contexto das mudanças climáticas, a sobrevivência e a produtividade das plantações de eucaliptos poderão ser afetadas. Assim, são necessárias pesquisas em nutrição florestal, como a avaliação do K e do Na e sua interação com a disponibilidade hídrica com o crescimento e propriedades do lenho de eucaliptos. Em experimento instalado, em 20 de junho de 2010 de tipo \"Split-plot\", foram avaliadas as árvores de Eucalyptus grandis submetidas a dois regimes hídricos (100% e 63%) e três tipos de fertilização (K, Na e controle). O diâmetro do tronco (cada 15 dias, com dendrômetros) e a altura total (cada 6 meses) das árvores foram mensurados no período do 40º ao 61º mês. A umidade do solo foi analisada semanalmente e a precipitação e temperatura diariamente. Foram analisadas as propriedades do lenho de 48 árvores, no 47º mês, por amostragem destrutiva, avaliando-se a sua densidade aparente, densidade básica, estrutura anatômica e proporção cerne/alburno. Os resultados mostraram que a precipitação influenciou significativamente o crescimento das árvores, seguindo-se a temperatura mínima e a umidade do solo. O K e o Na mostraram interação com a precipitação, (i) no período seco, com a redução do incremento do tronco das árvores com o Na e a sua paralisação com o K, (ii) no período chuvoso, com o aumento do incremento em diâmetro e altura do tronco, em relação ao controle. O Na em relação ao K resultou em menor crescimento das árvores de eucalipto. Com a exclusão de 37% da chuva houve efeito negativo nas árvores com K; no tratamento controle e com aplicação de Na a exclusão não mostrou efeito significativo até o 58º mês. Em relação à (i) densidade do lenho das árvores- ocorreu a sua diminuição com K e Na (menor com Na), e incremento com a menor disponibilidade hídrica; K não diminuiu a densidade sob maior disponibilidade hídrica; (ii) anatomia do lenho- observaram-se vasos de maior diâmetro e menor frequência com K e Na (maior com K); as fibras apresentaram variação significativa com Na (com fibras mais longas e largas com menor espessura da parede); a menor disponibilidade hídrica resultante da exclusão de 37% da chuva não afetou aos vasos e fibras; (iii) relação cerne/alburno- o K e Na promoveram a formação de maior proporção de cerne em relação às árvores do tratamento controle, sem influência significativa da exclusão parcial de chuva. Relações entre anatomia e densidade do lenho mostraram que mudanças nas dimensões das fibras foram acompanhadas de mudanças na densidade do lenho; e maior taxa de crescimento nem sempre se relaciona com a diminuição da densidade do lenho. Os resultados indicaram que a perda de características desejáveis na densidade, fibras e proporção de alburno, com a adição de K ou Na (principalmente Na) na adubação básica, são altamente compensados pela maior produção de lenho, no entanto em regiões mais áridas e com maior risco de seca prolongada, potássio e sódio podem agravar o déficit hídrico. / In the context of climate change, survival and productivity of eucalyptus plantations may be affected. Thus, research is needed on nutrition and forest ecophysiology, such as the evaluation of K and Na and their interaction with water availability on the growth and wood properties of eucalyptus. In a split-plot type, experiment installed on June 20, 2010 we evaluated Eucalyptus grandis trees submitted to two water regimes (100% and 63%) and three fertilizer supplies (K, Na and control). The stem diameter was measured every 15 days with dendrometers and total height, every 6 months in the period from 40th to 61st month. Soil moisture was analyzed weekly and precipitation and temperature daily. The wood properties of 48 trees were analyzed after 47 months, by destructive sampling, evaluating their apparent density, specific gravity, anatomical structure and heartwood/sapwood proportion. The results showed that precipitation significantly influenced the growth of the trees, followed by the minimum temperature and soil moisture. K and Na showed interaction with precipitation, (i) in the dry season, by reducing the growth of the tree trunks with Na and its stoppage with K, (ii) during the rainy season, with increasing growth in diameter and height of the trunk, compared with the control. The Na, as compared to K, resulted in lower growth of the eucalyptus trees. With the artificial exclusion of 37% of throughfall there was a negative effect on the growth of trees fertilized with K; but in the control and Na treatment the rainfall exclusion showed no significant effect until 58º month. In relation to (i) density of the wood of trees, there was a decrease in K and Na (lower with Na), and an increase with lower water availability; although the K did not reduce the density under higher water availability; (ii) wood anatomy- larger vessels with lower frequency were formed with K and Na supply (with higher K); the fibers showed significant variations with Na (longer and wider fibers with smaller wall thickness); and the lower water availability from the of 37% rainfall exclusion did not affect vessels and fibers; (iii) Heartwood/sapwood ratio; K and Na promoted the formation of larger proportion of heartwood in relation to the trees from the control treatment, and there was no significant influence of the partial rainfall exclusion. Relationships between anatomy and wood density showed that changes in fiber dimensions were accompanied by changes in the wood density; and the higher growth rate is not always associated with decreased wood density. The results indicate that the loss of desirable characteristics in density, fiber and proportion of sapwood, with the addition of K or Na (mainly Na) in the basic fertilization are highly compensated by the increased wood production, though in more arid regions with increased risk of prolonged drought, potassium and sodium can aggravate water deficit.

Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The extraction of hemicelluloses prior to pulping that would have been dissolved in black liquor during pulping process, is an attractive alternative for pulp and paper mills as they, in addition to their core products, can increase their revenue by producing biofuels, biopolymers, paper additives and other chemicals. However, the amount of hemicelluloses extracted will be limited by the requirement to maintain pulp yield and pulp quality in comparison to existing pulping processes. In the present study, mild alkaline (NaOH) and dilute sulphuric acid conditions were used to extract hemicelluloses from Eucalyptus grandis, giant bamboo (Bambusa balcooa) and sugarcane (Saccharum officinarum) bagasse (SCB) prior to kraft or sodaAQ pulping processes. The effects of catalyst concentration, temperature and reaction time on hemicelluloses pre-extraction were studied, using a statistical experimental design to investigate conditions under which hemicelluloses could be extracted prior to alkaline pulping with minimal interference on cellulose (glucan) content. Subsequently, selected pre-extracted materials were subjected to kraft or sodaAQ pulping to evaluate the effect of the hemicelluloses pre-extraction on cooking chemicals, pulp yield and properties. This study also included evaluation of hot water hemicelluloses pre-extraction of SCB as it was part of a dilute sulphuric acid experimental design. The pulp yield, cooking chemicals and handsheet strength properties were compared with those obtained from kraft or sodaAQ pulping of non extracted raw materials. The results showed that alkaline pre-extraction options investigated preserves the pulp yield with minimal effect on handsheet strength properties depending on the choice of the subsequent pulping method while a fraction of xylan was extracted in polymeric form. In addition, less active alkali was required to delignify the xylan extracted materials. The integration of hemicelluloses pre-extraction by alkaline methods into a kraft pulping process was preferred for giant bamboo and E. grandis since it maintained pulp yields at desired industrial levels of 50%, and pulps within a bleachable kappa number range. Another advantage observed was the reduction in total cooking active alkali required to delignify alkaline extracted giant bamboo or E. grandis by 8or 3 percentage points respectively. However, the compromise to maintain the pulp yield was obtained when only 13.6% or 12.4% polymeric xylan was solubilised from giant bamboo or E. grandis respectively. Slight improvement in burst index of the handsheet was observed for extracted giant bamboo. On the other hand, pulp viscosity was increased by 13% due to the removal of low molecular weight hemicelluloses, while the breaking strength of the handsheet was also increased by 8.9% for pulps produced from extracted E. grandis. In the case of sugarcane bagasse, hemicelluloses pre-extraction by alkaline methods integrated well with the sodaAQ pulping process. It enabled a xylan recovery of 69.1%, while providing pulp with higher screened pulp yield (45.0%), with an advantageous decrease in kappa number (15.5). The handsheet tear index was superior without reduction in viscosity compared to pulp produced from non extracted SCB. On the contrary, results obtained from optimised dilute sulphuric acid pre-extraction of all the tested feedstocks were found to negatively impact subsequent kraft or sodaAQ pulping processes resulting in lower pulp yields and poorer strengths properties. Nonetheless, the differences were better when sodaAQ pulping was used compared to kraft pulping. SodaAQ protects the carbohydrates against the peeling reaction under alkaline medium. Conversely, pre-extraction of SCB with hot water resulted in low concentration of xylooligomers (5.7%), while the subsequent sodaAQ pulping resulted in no pulp yield reduction. The tear index and optical brightness of the handsheet papers produced from hot water extracted SCB were slightly improved while the breaking length, tensile and burst indexes were similar to those of pulps produced from non extracted SCB fibres. Of equal importance were the observed higher tear and burst indexes of handsheets produced from giant bamboo compared to E. grandis for both extracted and non extracted materials prepared under similar pulping processes. The advantage of bamboo was due to the larger fibre length and different morphological properties to those of hardwoods. However, the pulps produced from giant bamboo showed higher kappa numbers than those pulps produced from E. grandis due to the high condensation behaviour of bamboo lignins under alkaline conditions. Higher kappa numbers explained the higher demand for subsequent bleaching chemicals. In conclusion, the pulp mill biorefinery concept through hemicelluloses pre-extraction with NaOH can be achieved with modified kraft pulping or the sodaAQ pulping processes, but it depends on the type of raw material, extraction method and quality and performance requirements of a particular paper. The low pulping chemicals demand, comparable pulp yields and the improvement in some physico-chemical properties of the pulps from preextracted materials were observed. Furthermore, owing to xylan pre-extraction a larger amount of (extracted) material could be loaded into the digester as when non-extracted materials were used. / AFRIKAANSE OPSOMMING: Ekstraksie van hemiselluloses wat tydens verpulping in die swartloog opgelos word, bied ‘n aantreklike alternatief aan pulp- en papiermeulens om, addisioneel tot hul hoofprodukte, hul inkomste deur die vervaardiging van biobrandstowwe, biopolimere, papierbymiddels en ander chemikalië, daardeur te kan verhoog. Die hoeveelheid hemiselluloses wat ge-ekstraheer kan word, sal egter beperk word deur die vereiste dat pulpopbrengs en –kwaliteit tydens bestaande verpulpingsprosesse gehandhaaf moet word. In hierdie ondersoek is matige alkaliese (NaOH) en verdunde swawelsuurtoestande gebruik om hemiselluloses vóór kraft- of natriumantrakinoonverpulping uit Eucalyptus grandis, reuse bamboes (Bambusa balcooa) en suikerriet (Saccharum officinarum) bagasse, mee te ekstraheer. Die invloed van katalisatorkonsentrasie, temperatuur en reaksietyd is mbv ‘n statistiese, eksperimentele ontwerp ondersoek om die toestande te bepaal waaronder hemiselluloses, met minimale effek op die sellulose (glukaan) –inhoud, vóór alkaliese verpulping ge-ekstraheer kan word. Die pre-ge-ekstraheerde materiale, met hoë glukaan- en voldoende hemisellulosesinhoud, is vervolgens aan kraft- en natriumantrakinoonverpulping onderwerp om die invloed van pre-ekstraksie van hemiselluloses op die verpulpingsreagense, pulpopbrengs en - eienskappe vas te stel. Hierdie studie het ook die evualering van warmwater hemisellulosespre-ekstraksie van suikerrietbagasse, wat deel is van ‘n verdunde swawelsuur eksperimentele uitleg, ingesluit. Pulpopbrengs, die hoeveelheid verpulpingsreagense en handveleienskappe van dieselfde materiale wat nie vooraf ge-ekstraheer is nie, is vergelyk. Die resultate toon dat alkaliese pre-ekstraksie metodes wat ondersoek is die pulpopbrengs met minimale effek op handvel sterkte-eienskappe afhangende van die keuse van daaropvolgende pulpmetode kon handhaaf terwyl ‘n fraksie van xilaan in polimeriese vorm ge-ekstraheer is. Addisioneel, is minder aktiewe alkali benodig om die xilaan ge-ekstraheerde materiale te delignifiseer. Die integrasie van hemisellulosespre-ekstraksie dmv alkaliese metodes tydens ‘n kraft verpulpingsproses is vir reuse bamboes en E. grandis verkies omdat pulpopbrengste op ideale industriële vlakke van 50% gehandhaaf en is en pulp in ‘n bleikbare kappa nommergebied interval kon lewer. ‘n Verdere voordeel wat waargeneem is was die vermindering in die totale gekookte aktiewe alkali benodig vir reuse bamboes of E. grandis met 8 of 3 persentasiepunte onderskeidelik. Die kompromie om die pulpopbrengs te handhaaf is verkry toe slegs 13.6% of 12.4% polimeriese xilaan opgelos is vanuit reuse bamboes of E. grandis onderskeidelik. ‘n Effense verbetering in bars-indeks van die handvelle is waargeneem vir ge-ekstraheerde reuse bamboes. Pulpviskositeit het met 13% gestyg agv die verwydering van die lae molekulêre massa hemiselluloses, terwyl breeksterkte van handvelle ook met 8.9% toegeneem het vir pulp verkry uit pre-gekstraheerde E. grandis. NaOH pre-ekstraksie van 69.1% xilaan (droë massa) uit suikerriet bagasse (SCB) het ‘n hoër natriumantrakinoon, gesifte pulpopbrengs gelewer (45.0%) met ‘n verbeterde afname in kappa-getal (15.5) en uitstekende skeursterkte sonder verlaging in viskositeit, soos vergelyk met nie-ge-ekstraheerde suikkerrietbagasse. Daarteenoor het die resultate verkry met die geoptimeerde verdunde swawelsuur preekstraksie van al die getoetste rumateriale getoon om‘n negatiewe effek te gehad het op die daaropvolgende kraft- of natriumantrakinoonverpulping dws het laer pulpopbrengste en swakker sterkte-eienskappe opgelewer. Die verskille was nietemin kleiner toe natriumantrakinoonverpulping ipv kraftverpulping gebruik is. Antrakinoon beskerm die koolhidrate teen die afskilreaksie in alkaliese medium. Daarteenoor het pre-ekstraksie van suikerrierbagasse met warm water tot 'n lae hoeveelheid (5.7%) xilaanoligomere gelei, terwyl die daaropvolgende natriumantrakinoonverpulping geen verlaging in pulpopbrengs veroorsaak het nie. Skeursterkte en optiese helderheid van handvelle wat uit warm water ge-ekstraheerde suikerrietbagasse vervaardig is, het ietwat verbeter terwyl breek-, trek- en barssterkte dieselfde was as van suikerrietbagasse pulp wat nie ge-ekstraheer is nie. Net so belangrik was die waargenome hoër skeur- en barsindekse van handvelle vervaardig van reuse bamboes in vergelyking met E. grandis van beide geekstraheerde en nie ge-ekstraheerde materiale voorberei onder dieselfde verpulpings toestande. Bamboes se sterker eienskappe was as gevolg van die hoër vesellengte en ander morfologiese eienskappe as diévan loofhout. Pulp wat vervaardig is van reuse bamboes het ‘n hoër kappanommer getoon as pulp van E. grandis as gevolg van die hoë kondensasiegedrag van bamboeslignien onder alkaliese toestande. Hoër kappanommers kon die gepaardgaande hoër aanvraag vir bleikchemikalieë verklaar. Ten slotte, die pulpmeul bio-raffinaderykonsep nl. deur hemisellulosesekstraksie met NaOH gekombineer met óf ‘n gemodifiseerde kraft verpulping óf ‘n gemodifiseerde natriumantrakinoon verpulping, is wel uitvoerbaar. Dit word egter sterk beïnvloed deur die tipe ru-materiaal en die ekstraksie-metode gebruik, asook deur die kwaliteits- en gebruiksvereistes van verskillende tipes papier. ‘n Lae aanvraag vir verpulpingschemikalieë, vergelykbare pulpopbrengste en die verbetering in fisies-chemiese eienskappe van pulp vanaf pre-ge-ekstraheerde materiale is waargeneem. Verder kon, as gevolg van xilaan ekstraksie, meer ge-ekstraheerde materiaal in die verteerder gelaai word as wanneer nie-ge-ekstraheerde materiaal gebruik is.

Thesis (PhD (Forest and Wood Science))--Stellenbosch University, 2007. / ENGLISH ABSTRACT: There has been a reported reduction in the durability of creosote treated, wooden utility poles in South Africa in recent years. Several factors could have been responsible for this. In this study, Eucalyptus grandis pole drying schedules currently used, methods of measurement of moisture content (MC) after drying and drying defects were investigated. Relationships involving drying defects and MC gradient before treatment which may help in the development of simple nondestructive methods of assessing defects such as surface checking, honeycomb and collapse, and MC gradient were also explored. The long term goal of this study was to increase the durability of treated poles by avoiding unacceptable drying defects and MC values before treatment. The results of this investigation are presented in the following chapters: an introduction motivating the aims of the investigations (Chapter 1); a review of literature relevant to MC and drying defects in sawn or round wood (Chapter 2); ready for press manuscripts on MC and drying defects in kiln-dried E. grandis poles (Chapters 3 to 7) and a general conclusion that links up chapters 3 to 7, and recommendations (Chapter 8). The auger drill method gave reliable MC values when samples in increments of 25 mm depths into the pole were taken. However, when single samples of 50 mm and 75 mm depths were considered, the auger drill MC measurements were unreliable. It was concluded that SABS SM 983 (2000), which specifies taking single radial auger drill samples of depth 70±5 mm at pole mid length, is not a reliable method of measuring MC in a kiln-dried E. grandis pole. Correlation results indicated that tree growth factors such as sapwood depth, green MC and heartwood percentage were related to final drying defects and may be used as criteria for pole sorting before kiln drying. Also, the number of valleys per unit length (VPUL) of the circumference at the theoretical ground line (TGL) was positively correlated with honeycomb and closed surface checks, implying that VPUL as a parameter of the pole circumference profile can be used to assess invisible, internal defects. The dry bulb temperature (Tdb) of 80oC, used to dry poles in industry, was too high and resulted into unacceptable levels of drying defects in kiln dried E. grandis poles. In addition, the drying period of 8 days was too short to attain an acceptable MC gradient in poles. It is, therefore, recommended that: To use the auger drill method to reliably determine the moisture content of a pole, samples in increments of 25 mm should be taken. MC measurements should be made at the most critical zones of a pole such as the TGL and not higher up since there is normally considerable MC variation in the longitudinal direction. It is also important to consider sampling more than one position on the pole circumference to cater for the MC variation in the tangential direction. For poles with large sapwood depths i.e. >15mm, mild drying conditions at the beginning of a drying run should be used, since such poles may be more susceptible to surface checking. Poles with large heartwood percentages should also be dried with suitable kiln schedules, i.e. with low Tdb to minimise honeycomb and collapse. In general, Tdb lower than 80oC should be considered in order to reduce the defects to acceptable levels. Poles should be dried for longer than 8 days even at Tdb as high as 80oC to reduce the MC to acceptable values and gradients. Since only three schedules were tested, more drying schedules should be investigated to make reliable conclusions about the effect of schedule on drying defects. In addition, more poles per schedule should be considered in order to obtain statistically reliable results. The relationship of pole diameter and drying defects also requires further investigation. Since a limited sample was used to test for the effect of source of poles and drying schedules on defect correlations, further studies should be done on sufficient samples to come up with more reliable conclusions. It is also necessary to further investigate the possible variation in correlation of VPUL and internal defects on a large sample of poles from specific sources and drying schedules. / AFRIKAANSE OPSOMMING: Die afgelope paar jaar is waargeneem dat kreosootbehandelde transmissiepale 'n afname in duursaamheid toon. Verskeie faktore kan hiervoor verantwoordelik wees. In hierdie studie is huidige Eucalyptus grandis oonddrogingskedules en voggehalte- (VG) bepalingsmetodes vóór en na droging asook drogingsdefekte ondersoek. Verwantskappe tussen drogingsdefekte en VG-gradiënt vóór behandeling wat kan meehelp om nie-destruktiewe metodes te ontwikkel om defekte soos oppervlaktekrake, interne barste en instorting en VG-gradiënt te bepaal, is ook bestudeer. Die langtermyn doelwit van hierdie studie is om die duursaamheid van behandelde pale te verbeter deur onaanvaarbare drogingsdefekte en voggehaltes vóór behandeling te vermy. Die resultate van hierdie ondersoek word in die volgende hoofstukke bespreek: 'n inleiding waarin die doelwitte van die onderskeie ondersoeke motiveer word (Hoofstuk 1); 'n oorsig van die literatuur relevant tot VG en drogingsdefekte in gesaagde en rondehout (Hoofstuk 2); persklaar manuskripte oor VG en drogingsdefekte in oondgedroogde E. grandis pale (Hoofstukke 3 tot 7) en 'n algemene gevolgtrekking wat bevindings uit hoofstukke 3 tot 7 saamvat gevolg deur aanbevelings (Hoofstuk 8). Die augerboor-metode kon betroubare VG-waardes lewer indien monsters van 25mm diepteinkremente in die paal geneem is. Augerboor-voggehaltemetings met enkel 50mm en 75mm monsters was egter onbetroubaar. Daar is bevind dat SABS SM 983 (2000), wat 'n enkel radiale augerboormonster tot op 'n diepte van 70±5 mm in die middel van die lengte van die paal spesifiseer, nie 'n betroubare VG-bepalingsmetode vir oondgedroogde E. grandis pale is nie. Die resultate het aangetoon dat boomgroeifaktore soos spinthoutdiepte, groen voggehalte en die persentasie kernhout aan drogingsdefekte verwant is en as basis vir sortering van pale vóór oonddroging gebruik kan word. Ook kon die aantal valleie per eenheidslengte (e. VPUL) van die omtrek by die teoretiese grondlyn (TGL) positief met interne barste en geslote oppervlaktekrake korreleer word wat impliseer dat VPUL as parameter van die omtrekprofiel van die paal gebruik kan word om onsigbare, interne defekte mee vas te stel. Die droëbaltemperatuur (Tdb) van 80oC wat in die industrie gebruik word, was te hoog omdat dit onaanvaarbare vlakke van drogingsdefekte in oondgedroogde E. grandis veroorsaak het. Daarbenewens was die drogingsperiode van 8 dae by 'n Tdb van 80oC te kort om 'n aanvaarbare VG-gradiënt te lewer. Die volgende word derhalwe aanbeveel: Om betroubare VG-resultate d.m.v. die augerboormetode te verkry, behoort monsters in inkremente van 25mm geneem te word. VG-metings behoort in die mees kritiese dele van 'n paal gedoen te word byv. by TGL en nie hoër nie omdat daar normaalweg beduidende VG-variasie in die longitudinale rigting is. Dis ook belangrik om op meer as een posisie op die omtrek te meet om vir die variasie in die tangensiale rigting voorsiening te maak. Ligte drogingstoestande behoort aan die begin van die drogingsproses by pale met groot spinthoutdieptes, bv. > 15mm, gebruik te word omdat sulke pale meer geneigd tot oppervlaktekrake is. Pale met hoë kernhoutpersentasies moet ook met geskikte drogingskedules, bv. met lae Tdb, gedroog word om interne barste en ineenstorting te verminder. Oor die algemeen behoort Tdb laer as 80oC oorweeg te word om die omvang van defekte by aanvaarbare vlakke te hou. Selfs by Tdb so hoog as 80oC behoort pale langer as 8 dae te droog om die VG tot by aanvaarbare waardes en 'n gradiënt te bring. Omdat slegs drie skedules evalueer is, behoort meer skedules ondersoek word om betroubare gevolgtrekkings oor die effek van skedule op drogingsdefekte te verskaf. Addisioneel behoort meer pale per skedule oorweeg word om statisties betroubare resultate te verkry. Die verwantskap tussen paaldeursnee en drogingsdefekte benodig ook verdere ondersoek. Aangesien 'n beperkte aantal pale gebruik is om die herkoms en drogingskedule met defekte te korreleer, behoort verdere studie op genoeg pale gedoen te word om meer betroubare gevolgtrekkings te kry. Dit is ook noodsaaklik om die moontlike variasie in die korrelasie tussen VPUL en interne defekte op 'n groot aantal pale van spesifieke herkoms en drogingskedules vas te stel.

Student Number : 9202137P - MSc Dissertation - School of Animal, Plant and Environmental Studies - Faculty of Science / The Reconstruction and Development Programme’s Mpumalanga Working for Water Programme (WWP) has cleared exotic and commercial weed species from the riverine environment since 1994. This study serves as an assessment of the impact and modification caused as a result of invasion and the subsequent clearing of the exotic vegetation on flora in the riverine zone of the Sabie River Catchment. The experimental design compares the before and after clearing effects and includes altitude and invasion intensity variables. The investigations included: in situ soil seed banks, environmental modification, vegetation structure, species diversity and effectiveness of clearing. Clearing and invasion by exotic species altered soil chemical, physical and ground cover parameters. The extent of these modifications was dependent on the extent of invasion and clearing done within the community. Clearing of exotic species however, acted as an additional disturbance to that caused by invasion. Environmental modifications that occurred with clearing and invasion within the study were positively related to percentage soil organic matter, and ground cover (soil, litter, vegetation). Invasion by exotic species alters the vegetation structure, the extent of which was directly related to the invasion intensity. The main source of vegetation structure modification is attributed to tall growing exotic species such as Eucalyptus grandis and Solanum mauritianum. Both of these species dominated the indigenous vegetation, E. grandis by expanding the upper canopy and S. mauritianum by dominating the mid canopy. Clearing of invasive vegetation resulted in an additional disturbance proportional to the extent of invasion intensity. Invasion did not result in any large changes to the vegetation at low intensity but clearing at this intensity increased the disturbance and altered the vegetation structure. Soil seed banks were limited in the number of species and dominated by two exotic species. The soil seed bank of woody species related positively to the community species richness. The total soil seed bank density did not relate to invasion intensity or clearing thereof but propagules of individual species within the soil seed banks did. The seeds of the exotic species, Acacia mearnsii and S. mauritianum, illustrated burial as prerequisite for persistence in the soil seed bank. A. mearnsii and S. mauritianum seeds were found to have half-life’s of up to 25 years and 13 months respectively. The species richness and diversity varied only marginally because of invasion and clearing. Species alpha diversity increased with clearing due to weedy and pioneer species establishment. Beta diversity effectively highlights the species turnover with clearing and invasion. Success in eradication of exotic species had mixed results. Clearing of high invasion sites was effective but in lower invasion categories a number of exotic individuals were missed. Clearing effectiveness was good for certain species such as E. grandis and Pinus patula, but poor for others such as S. mauritianum. Coppicing is a significant issue for E. grandis and S. mauritianum. The persistence of individuals (coppicing & missed individuals) coupled with very large persistent seed banks has repercussions for the clearing programme, as it may prevent effective eradication. Initially the WWP has been successful in removing exotic vegetation, however there is a failure to address the regenerative properties of some exotic species. Unless a rigid schedule of follow up clearing treatments occurs, an even larger invasion problem could exist.

Orientador: Celso Luís Marino / Coorientador: Marcio Luis Acencio / Banca: Douglas Silva Domingues / Banca: Iraê Amaral Guerrini / Banca: Esteban Roberto Gonzales / Banca: Edson Luiz Furtado / Resumo: Espécies de Eucalyptus têm sido utilizadas com sucesso para plantios florestais devido ao seu rápido crescimento, sua capacidade de adaptação às diversas condições climáticas e pelo seu potencial econômico na produção de energia, fibra e madeira sólida, reduzindo assim a pressão sobre as florestas tropicais e a biodiversidade associada. Investimentos em pesquisas e desenvolvimento estão sendo realizados pelo setor florestal, no intuito de aumentar os ganhos de produtividade através da pesquisa na área da biologia molecular. Visto que características anômalas nas progênies podem gerar perdas na produtividade, a identificação e caracterização dos genes relacionados a anomalias são muito importantes no auxílio em programas de melhoramento genético. Ao realizar um cruzamento controlado de Eucalyptus grandis, a empresa Suzano Papel e Celulose detectou uma anomalia com segregação mendeliana 3:1 (normais:anômalas) na progênie. As características eram bem significativas se comparadas com as plantas normais, tais como diferenças na altura, diâmetro da base do caule, tamanho das folhas e morte em poucos meses. Estudos anteriores identificaram uma marca molecular ligada à anomalia, e análises de comparação da sequência contra o banco de dados de eucalipto demonstrou identidade com proteínas da família Bet v1 PR10 (Pathogenesis-related protein 10), embora não estivesse claro o envolvimento deste gene no desenvolvimento da anomalia. Outros estudos traçaram o perfil transcricional dos fenótipos contrastantes pela técnica de RNAseq. Dentre os genes diferencialmente expressos, através do enriquecimento funcional, destacaram-se os pertencentes as famílias Bet v1, quitinase classe I e taumatina, todos relacionados à resposta contra patógenos, sugerindo que a anomalia seja causada pela ativação do sistema imune da planta (resposta autoimune). Com o intuito de se obter mais informações sobre à patogênese da... / Abstract: Eucalyptus species have been successfully used for forest plantations. Some intrinsic features such as rapid growth, adaptability to various weather conditions and economic potential in energy production, fiber and solid wood, help to reduce pressure on tropical forests and associated biodiversity. Investments in research and development on molecular biology arebeing carried out by forestry sector in order to increase productivity gains. Since anomalous characteristics of progeny may generate productivity loss, gene identification linked to abnormalities are crucial for breeding programs. During a controlled crossing with Eucalyptus grandis, the Suzano Papel e Celulose enterprise detected an atypical Mendelian segregation 3: 1 (normal: abnormal). Significant phenotypic differences concerning height, stem base diameter, and leaf size appeared, as well as an unusual early death, when compared to normal plants. Previous studies identified a molecular tag attached to this anomaly. Sequence comparison analysis of eucalyptus database showed identity with Bet v1 PR10 protein family (Pathogenesis-related protein 10). However, gene involvement in developing such aberration is undetermined. Other studies found a transcriptional profile of contrasting phenotypes by RNAseq technique. Among differentially expressed genes by functional enrichment highlighted those belonging to Bet v1 families, chitinases class I, and thaumatin, all related to pathogenic response. This fact suggests that aberration is caused by the plant immune system activation (autoimmune response). To investigate the pathogenesis of such genetic disorder, three approaches were adopted: (i) SNPs identification among the differentially expressed genes of Bet v1 families, chitinase, and thaumatin, (ii) miRNAs identification with potential binding to mRNAs differentially expressed genes, and (iii) check of possible influence of differentially expressed gene products on ... / Doutor

As preocupações com o ambiente e com a saúde da população exigem que a cada dia uma maior porcentagem de esgotos sanitários sejam tratados. Entretanto esse tratamento é responsável por um novo problema: as quantidades de lodo geradas. Uma das alternativas para destino final desse resíduo, que após devidamente higienizado e condicionado passa a ser conhecido como biossólido, é o seu uso racional no solo com culturas que não são destinadas a consumo direto como é o caso dos plantios florestais. Nesse aspecto, são necessários estudos procurando avaliar em longo prazo, os efeitos benéficos do biossólido no fornecimento de nutrientes e também os prováveis prejuízos causados pela presença de metais pesados. No presente estudo é feita a avaliação dos parâmetros de fertilidade de Latossolo Vermelho-Amarelo Distrófico típico, A moderado, textura média, em várias profundidades (0-10, 10-20, 20-30, 30-60 e 60-90 cm) e dos teores de N e dos metais Cd, Cr, Cu, Ni e Zn no solo e em folhas de Eucalyptus grandis, numa área onde, há cinqüenta e cinco meses, foi feita a aplicação de biossólido em doses de 10, 20 e 40 t ha-1. O ensaio foi montado em 1998 seguindo um delineamento com 6 tratamentos dispostos em quatro blocos aleatorizados totalizando 24 parcelas experimentais. Os resultados obtidos, 55 meses após a aplicação do biossólido, permitiram as seguintes conclusões: 1. embora a aplicação de biossólido em quantidades superiores a 20 t ha-1 tenha resultado em aumento dos teores de N-total em profundidade no solo, este incremento não supõe riscos ambientais diferentes dos decorrentes da fertilização mineral; 2. a concentração foliar de nitrogênio não foi influenciada pelo aporte de nitrogênio do biossólido; 3. as doses utilizadas de biossólido não proporcionaram aumentos nos teores dos metais Cd e Cr no solo e não foram verificadas evidências de fitodisponibilidade desses metais; 4. os teores de Cu, Ni e Zn extraíveis aumentaram com o tempo decorrido desde a aplicação do biossólido, indicando a possibilidade de mobilidade e fitodisponibilidade desses metais no solo quando da aplicação do biossólido na dose de 40 t ha-1 (base seca). Não obstante, estes aumentos não representaram risco para a cultura do eucalipto. / Concern regarding environmental quality and human health demands wastewater treatment technology and, with this treatment, sewage sludge is generated. The sewage sludge, after a properly microorganism reduction and physically conditioning, is usually known as biosolid. One of the alternatives for biosolid final disposal is the application in agriculture in areas with cultures not used for food consumption such as planted forestry. In this case it is necessary to evaluate, in long term studies, on the efficiency of the biosolid as a nutrient source supply as well as the possible harm effects considering the heavy metals content in the waste. In this study, an evaluation on N and Cd, Cr, Cu, Ni and Zn in soil (Typic Haplorthox) and in Eucalyptus grandis leaves, was effected in an experimental area where biosolid was applied in levels of 10, 20 and 40 t ha-1, 55 months ago. The experimental design adopted was randomized blocks, for treatments and replications. The results obtained, after 55 months of biosolid application, were: 1. there was an increase on nitrogen level in the deepest soil layer that was evaluated (60-90cm) due to biosolid application in levels of 20 or 40 t ha-1 , but the environmental risk of this increase is not different from the one that is caused by the use of mineral fertilizers; 2. the nitrogen level in Eucalyptus grandis leaves was not affected by biosolid application; 3. levels of Cd and Cr did not increase in the soil and no availability of those metals to the trees was observed; 4. there was an increase, over time, in the soil level of Cu, Ni and Zn removed by Mehlich extractant, in the treatment using 40 t ha-1 of biosolids. These increases indicate the possibility of mobility and plant availability of those metals, although these increases did not represent any harm effects to Eucalyptus grandis trees.

A atividade florestal apresenta-se como um vetor de desenvolvimento social, ambiental e econômico no Brasil. Em 2004 as exportações ligadas ao setor renderam US$ 7 bilhões e contribuíram com US$ 5,5 bilhões em impostos. No mesmo ano, no Brasil, dos 6 milhões de hectares de reflorestamento comercial, mais de 50% dos hectares são ocupados por eucalipto. Esta cultura pode ser utilizada para diversas funções, desde à produção de papel e celulose, até a produção de carvão vegetal. Mas a produtividade desta cultura atualmente tem uma série de fatores limitantes. Destes fatores, um dos mais severos é uma doença denominada ferrugem, causada pelo fungo Puccinia psiddii Winter. Este patógeno entre tanto, não é conhecido nos centros de origem do gênero Eucalyptus, mas, utiliza como hospedeiros vários gêneros das Mirtáceas, infectando folhas, flores e frutos em desenvolvimento. O controle da doença é normalmente realizado mediante o uso de fungicidas. Porém, a utilização de plantas resistentes é o método mais aconselhável por diversos motivos, como o baixo custo, a praticidade e o menor impacto ambiental. Neste trabalho a metodologia do SAGE - Serial Analysis of Gene Expression foi utilizada, para a análise da expressão gênica uma vez que permite detectar e quantificar, de maneira global, a expressão de genes conhecidos e desconhecidos, envolvidos no processo de resistência à ferrugem. Neste trabalho analisou-se a expressão do conjunto de genes diferencialmente expressos e 200 genes sem diferenças no padrão de expressão, em Eucalyptus grandis infectado com Puccinia psidii. Utilizou-se para esta análise, indivíduos susceptíveis e resistentes à infecção por Puccinia psidii Winter. A população amostrada constituída por meios irmãos, apresentava segregação para o carácter de resistência à ferrugem. Os resultados produzidos permitiram identificar 421 genes com expressão diferencial (p ≤ 0,05) nos dois fenótipos. Vários destes genes estavam relacionados a diversos mecanismos de defesa da planta, tais como genes envolvidos na formação de barreiras físicas e na resposta hipersensível, resistência sistêmica adquirida, bem como genes relacionados à polarização celular e resposta ao estresse oxidativo. Os dados em conjunto, corroboram a idéia de que são vários os mecanismos que atuam simultaneamente produzindo o fenótipo resistente. Estes genes apresentam-se para serem utilizados futuramente como marcadores moleculares na seleção de indivíduos resistentes, em cruzamentos naturais ou dirigidos e como fonte de genes para experimentos de transformação em estudos mais profundos de fitopatogênese. / In Brazil the forest activities represent a vector for social, ambiental and economic development. In 2004 the exportations produced US$ 7 billions and contributed with US$ 5,5 billion in taxes. In the same year, in Brasil, of 6 million hectares of commercial reforestation, around 50% is occupied by eucalyptus. This crop can be used as the raw material for several industrial processes, from cellulose and paper production to vegetable charcoal production. However, eucalyptus productivity has several limiting factors. One of the most severe diseases is called rust, caused by the fungus Puccinia psiddii Winter. This pathogen is unknown in the Eucalyptus center of origin; however, it has several Myrtaceae genera as its host, infecting leaves, flowers and developing fruits. Rust management normally involves the use of fungicides, but the use of resistant plants is a much better alternative due the lower costs and minimal ambient impact. In the current study SAGE - Serial Analysis of Gene Expression was used for gene expression analysis because it is a quantitative genome-wide method and that obtains expression profiles from known and unknown genes involved in the rust resistant process. This thesis analyzed the expression profile of the differentially expressed genes and 200 genes without significant statistical differences in their expression patterns, in Eucalyptus grandis infected with Puccinia psidii. For this analysis we used susceptible and resistant individuals to Puccinia psidii Winter infection taken from a population half siblings, which showed segregation for fust resistance. The results indicated 421 genes with differential expression (p ≤ 0.05), 239 were preferentially expressed in the susceptible library and 232 in the resistant. Several of these genes were associated with plant defense mechanisms, such as genes involved in formation of physical barriers, hypersensitive response, systemic adquired resistance, genes related to cellular polarization and oxidative stress responses. All the data support the idea that not one but several mechanisms are acting at the same time producing the resistant phenotype. These genes are future candidates for molecular markers useful in the selection of resistant individuals in breeding programs and a source of genes for transformation experiments or as molecular tools to dissect the phytopathogenic process.