Made available in DSpace on 2015-03-26T13:30:19Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1669830 bytes, checksum: aa8f0b5ad8baa19129a43c823c004e96 (MD5) Previous issue date: 2008-05-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The present study was performed to obtain information on the biology of Oncideres saga (Dalman, 1823) and to evaluate the effects of its girdling of branches and trunks of Acacia mangium Willd. trees in terms of increase in diameter and height . The study on the biology of this insect pest was performed in a plantation of A. mangium located in Coimbra- MG, between September/2006-November/2007. Damage was assessed by collecting fallen branches and adults of this insect. The laboratory activities were performed in the Casa dos Cupins/UFV, in Viçosa-MG. The eggs of O. saga were of white coloration, of elongated shape, with length being approximately three times greater than the width average length of 3,54±0,03 mm and width 1,05±0,02 mm. The incubation period of eggs varied from 8 - 14 days and the viability was 52,89%. First instar larvae are whitish and semi- transparent, they have no legs, they have a prognathous head that is retracted in the prothorax, the antennae are short, and the mandibles are robust and short. The larvae average length was 2,92±0,04 mm, while the average widths of the body and of the head capsule were 1,02±0.01 mm and 0,62±0,01 mm, respectively. Sex of adults can be distinguished by total length of the antenna, with emphasis on the eleventh antennal segments. The occurrence period of O. saga was from January-April 2007 and the period of adult activity was 4 months. Adults of O. saga fed on the bark, on the epidermis of the leaf petiole (leafstalk) and also on the phyllode. Oviposition by O. saga in the branches of A. mangium was always close to the incision, with the egg being deposited between the bark and the xylem. There was only one egg per incision, rarely two and the average number of incisions for a girded branch was 80,33±16,81; the lower third had the largest amount of incisions (64,73%). It was found that 77,78% (n=9) of the girdle were made in the shaft. The average diameter of the girded branches was 6,68±0,70 cm and the average length of these branches was 3,45±0,16 m. With only one girdle, O. saga caused an average leaf loss of 135.069,4±24,354.4 cm2, which corresponds to a loss of 14,79% of foliar area of the tree. This beetle can therefore be considered an important defoliator of forests. The presence of one Scolytidae species was verified in branches of A. mangium girdled by O. saga, and four cerambycid species also emerged from these branches, which were identified as Engyum quadrinotatum Thomsom, 1864; Eburodacrys sexmaculata (Olivier, 1790); Achryson surinamum (Linnaeus, 1767) and Neoclytus pusillus (Laporte & Gory, 1838). Another experiment was carried out in May 2007 in order to evaluate the effect of sawing the main shoot of A. mangium. Blocks were randomized, and portions were subdivided according to ages of trees (from 40 - 46 months). Fifty-four trees were examined monthly in three blocks, in which three experimental treatments were applied, with six replicates for each one. The applied treatments consisted of "No damage" (T1= Control), "Artificial defoliation of the main shoot (T2) and "Artificial cut of the main shoot (T3). I also measured for each tree the total height (H) and the diameters with bark at 1,30 m (Breast diameter) and 20 cm (Base diameter) from the ground. It was concluded that the artificial cut of the main shoot (equivalent to girdling by O. saga) affected growth in diameter and in height. The effect on height was equivalent to the effect due to defoliation of A. mangium by O. saga. Thus, we conclude that this beetle can be considered as a serious defoliator in this forest system. / O presente estudo foi desenvolvido com o intuito de obter informações sobre a biologia de Oncideres saga (Dalman, 1823) e avaliar o efeito do roletamento do ponteiro principal de árvores de Acacia mangium Willd., realizado por este serrador, sobre o crescimento em diâmetro e altura. Os estudos foram realizados em um plantio de A. mangium localizado em Coimbra-MG. Primeiramente, estudou-se a biologia de O. saga de setembro/2006 a novembro/2007, através de vistorias no plantio com o intuito de avaliar o dano de O. saga, coletar galhos caídos e adulto deste inseto. As atividades de laboratório foram realizadas na Casa dos Cupins/UFV, em Viçosa-MG. Os ovos de O. saga apresentaram coloração branca, formato alongado, com comprimento aproximadamente três vezes maior do que a largura, estrutura do cório lisa, comprimento de 3,54±0,03 mm e largura de 1,05±0,02 mm. O período de incubação destes ovos variou de oito a 14 dias e a viabilidade foi de 52,89%. As larvas de primeiro ínstar apresentam tegumento esbranquiçado e semitransparente, são ápodas, do tipo cerambiciforme, com cabeça prognata e retraída para dentro do protórax; suas antenas são curtas, as mandíbulas robustas e curtas. O comprimento médio destas larvas foi de 2,92±0,04 mm, as larguras médias do corpo e da cápsula cefálica foram iguais a 1,02±0,01 mm e 0,62±0,01 mm, respectivamente. A época de ocorrência de O. saga foi de janeiro a abril de 2007 e o período de atividade de adultos foi de quatro meses. Adultos de O. saga se alimentaram da casca, do pecíolo das folhas e de parte do limbo foliar próximo do pecíolo. A oviposição por O. saga nos galhos de A. mangium foi realizada sempre próxima à incisão de postura, de modo a ficar entre a casca e o lenho. Foi encontrado um ovo em cada incisão de postura, raramente dois, e a média de incisões de postura por galho cortado foi de 80,33±16,81, apresentando o terço inferior a maior quantidade das incisões (64,73%). Adultos podem ser sexados com base no comprimento total da antena, com ênfase no décimo primeiro antenômero. Verificou-se que 77,78% (n=9) dos roletamentos foram realizados no fuste. O diâmetro dos galhos roletados foi de 6,68±0,70 cm e o comprimento destes galhos foi 3,45±0,16 m. Com apenas um roletamento, O. saga causou desfolhamento médio de 135.069,4±24.354,4 cm2, o que corresponde a uma perda de 14,79% da área foliar da árvore, e ele pode, assim, ser considerado um besouro desfolhador de essências florestais. Foi constatada a presença de um escolitídeo nos galhos de A. mangium roletados por O. saga e quatro cerambicídeos emergiram destes galhos, Engyum quadrinotatum Thomsom, 1864; Eburodacrys sexmaculata (Olivier, 1790); Achryson surinamum (Linnaeus, 1767) e Neoclytus pusillus (Laporte & Gory, 1838). Em outra etapa foi instalado um experimento para avaliar o efeito do corte do ponteiro principal de A. mangium, em maio de 2007, com delineamento em blocos ao acaso, e parcelas subdivididas no tempo em função das idades das árvores (40 a 46 meses). Foram avaliadas, mensalmente, 54 árvores dispostas em três blocos, nas quais foram aplicados três tratamentos, com seis repetições cada. Os tratamentos aplicados consistiram em Nenhuma injúria (T1=Testemunha), Desfolhamento do ponteiro principal (T2) e Corte do ponteiro principal (T3). Foram mensurados os diâmetros com casca a 1,30 m (DAP) e a 20 cm (DAB) do solo, e a altura total (H) de cada árvore no experimento. Como resultado, constatou-se que o corte do ponteiro principal, à semelhança do que faz O. saga, afetou o crescimento em diâmetro e em altura, e o efeito em altura é equivalente ao efeito devido ao desfolhamento, em A. mangium. Concluiu-se, assim, que o besouro serrador da espécie Oncideres saga pode ser considerado como besouro desfolhador, nesta essência florestal.

Submitted by PPG Engenharia e Tecnologia de Materiais (engenharia.pg.materiais@pucrs.br) on 2018-11-16T17:04:36Z No. of bitstreams: 1 Disserta??o homologa??o Viviane Bettanin 14.11.2018.pdf: 3436850 bytes, checksum: 12199a52b8023657a598a8254ca85c0f (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-11-19T13:58:36Z (GMT) No. of bitstreams: 1 Disserta??o homologa??o Viviane Bettanin 14.11.2018.pdf: 3436850 bytes, checksum: 12199a52b8023657a598a8254ca85c0f (MD5) / Made available in DSpace on 2018-11-19T14:07:36Z (GMT). No. of bitstreams: 1 Disserta??o homologa??o Viviane Bettanin 14.11.2018.pdf: 3436850 bytes, checksum: 12199a52b8023657a598a8254ca85c0f (MD5) Previous issue date: 2018-08-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / In order to reduce the environmental impacts caused by chemical harmful to the environmental and to human health, the development of natural substances that are able to substitute these dangerous components have been increased. Tannins are a group of natural poliphenolic components extracted from plants that could be used as corrosion inhibitors. This study investigates the utilization of two bark of black wattles (Acacia mearnsii) as corrosion inhibitors, Weibull and Macrospec, in acidic medium and in atmospheric environment and in aqueous CO2 rich medium under high pressure. API 5L X65 steel samples were exposed to a corrosive medium (0.1 M HCl) with different tannin concentrations. The best results were duplicate to an environmental with CO2 saturated water at 15 MPa and 50?C. In order to characterize the specimens scanning electron microscopy by gun field emission, energy dispersive spectroscopy, X ray diffraction, mass loss tests and potenciodynamic polarization tests were used. The results indicated that both tannins, at atmospheric pressure and 0.1 M HCl corrosive environment have similar performance as corrosion inhibitors, and the higher dosage tested (12 g/L) exhibited the best efficiency. However, when the tannins were tested in environment with presence of CO2 under high pressure (15 MPa) and 50?C the results were different, and only Macrospec tannin had an inhibitory action under the conditions tested. / Visando diminuir os impactos ambientais causados por subst?ncias qu?micas nocivas ao meio ambiente e ? sa?de humana, a procura por substitutos naturais destes compostos em diversas aplica??es vem sendo intensificada. Taninos compreendem uma classe de compostos polifen?licos naturais extra?dos de plantas, podendo ser usados como inibidores de corros?o em meio aquoso. Neste estudo avaliou-se a utiliza??o de dois taninos vegetais da ac?cia negra (Acacia mearnsii), Weibull (em p?) e Macrospec (l?quido), como inibidores de corros?o em meios ?cidos em ambiente atmosf?rico e em ambiente com a presen?a de CO2 a alta press?o. Corpos de prova de a?o API5L X65 foram expostos a meio acidificado com HCl 0,1 M com diferentes concentra??es de taninos e o melhor resultado no que se refere ? concentra??o do tanino para a inibi??o de corros?o foi replicado para um meio com ?gua saturada com CO2 a 15 MPa e 50?C. Para caracteriza??o foram realizadas as an?lises de microscopia eletr?nica de varredura, difra??o de raios X, medidas eletroqu?micas de polariza??o potenciodin?mica, e testes de perda de massa. Os resultados indicaram que ambos os taninos, em meio de HCl 0,1 M e press?o atmosf?rica, apresentaram desempenho similar no que diz respeito aos efeitos de inibi??o da corros?o e a maior dosagem utilizada (12 g/L) foi a que apresentou melhor efici?ncia de inibi??o. Por?m, quando testados em meio de ?gua saturada com CO2 a 50?C e 15 MPa o comportamento dos taninos foi distinto, sendo que apenas o tanino Macrospec teve a??o inibit?ria nas condi??es testadas.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The study of soil quality biological indicators in areas classified as forest production units is important to understand the ecological processes that occur in these systems. Monitoring the soil fauna in modified environments, when management practices involve chemical products in the environment, is an instrument that allows to evaluate not only the soil quality but also the proper functioning in a production system, since the soil fauna acts in decomposition and nutrient cycling, as well as in soil physical, chemical and biological properties. The objective of this study was to evaluate the herbicide application in a black wattle area (Acacia mearnsii De Wild.). Thus, the study was divided in three chapters. The first chapter aimed to evaluate the meso and macrophauna under different kinds and intensities of herbicides on the ground using the principal component analysis (PCA). The study was developed at Fundação Estadual de Pesquisa Agropecuária (Fepagro-Unidade Florestas) in Santa Maria/RS. The treatments were allocated as Randomized Blocks Design, with four repetitions per treatment, totalizing 64 experimental units, where two sampling plots were installed per unit using the meso and macrophauna capture PROVID method. The used herbicides were Glyphosate (4.0 l ha-1), Imazapyr (3.0 l ha-1), Oxyfluorfen (4.0 l ha-1) and Pendimethalin (3.0 l ha-1) besides hand cleaning and control without herbicide. The collects were done in the four seasons of the year (winter, spring, summer and autumn). From the calculated faunistic indexes, the taxonomic group average richness varied from 5.2 in the winter to 9.3 in the summer. The Shannon (H) diversity index was similar among all kinds and intensities of applied herbicides. This index (H) was different only between the seasons, varying from 0.58 in the spring to 1.21 in the summer. The PCA between the response and predictor variables clearly separated the component formation (taxonomic groups), significantly influenced by the kind of herbicides and application intensity. However, in PCA with additional predictor variable for the four most representative taxonomic groups (Araneae, Orthoptera, Collembola e Hymenoptera), it was observed that organism density in the group constituted by Collembola is strongly associated with the precipitation in the spring, whereas ants, Orthoptera, and spiders have their density better explained by the variable temperature. Different herbicides, as well as the intensity of the application on the ground caused no negative effects upon the biological parameters evaluated in the study, being the diversity and the density of meso and macrophauna conditioned only to the seasonal variations along the year. The study approached in the second chapter aimed to evaluate the influence of different kinds and intensities of herbicide application upon the soil physical properties, like density, macro, micro and total porosity, and aggregates average diameter (AAG). The experimental plot was the same described in chapter one. Two collections were done (before planting and after all herbicides application). Two soil samplings were collected in planting and interplanting seedling rows. The obtained results in the second collection showed that there is no significant difference between the evaluated parameters. For soil density, the highest values were found in treatments without herbicide (1.38 Mg m-3 in hand cleaning and 1.32 Mg m-3 in control). For macro, micro and total porosity the values were similar among them, for all kinds of tested herbicides, as well as for AAG. There was no herbicide direct influence upon the soil physical properties, since the weed competition was partially controlled, mainly in inter row seedlings planting, that might have contributed to maintain the soil physical structure in this area. In planting row, there was a fast soil particle reaccommodation because of the seedling roots. The third chapter aimed to evaluate the influence of herbicide application upon the symbiotic association between Rhizobium and the root systems from black-wattle seedlings, cultivated in plastic vessels under controlled environmental conditions in greenhouse. The study was established in Randomized Blocks Design, with four repetitions and ten plants per treatment, which were constituted by the same herbicides and doses mentioned in chapter one, besides a treatment without herbicide (control). The results in this study showed significant differences between the treatments and the variable dried biomass from rhizobic nodules in the black-wattle seedlings root system. All the herbicides used in vessels substrates induced the nodules formation, highlighting the herbicide Oxifluorfen (0.532 g plant-1), that showed a nodules biomass gain of 128.3% related to the control (0.233 g plant-1). Except for Glyphosate, the correlations between nodules biomass and the variables height, above ground biomass, and root biomass were all positive and significant. This way, the use of herbicide in the evaluated microenvironment caused no negative influence upon the physical and biological components (field), as well as on the microbiological component evaluated (greenhouse). / O estudo de indicadores biológicos da qualidade do solo em áreas consideradas como unidades de produção florestal é importante para o entendimento dos processos ecológicos que ocorrem nesses sistemas. Monitorar a fauna do solo em ambientes modificados pelo homem, sobretudo quando as práticas de manejo envolvem produtos químicos no ambiente, é um instrumento que permite avaliar não só a qualidade do solo, como também o próprio funcionamento de um sistema de produção, já que a fauna do solo atua na decomposição e ciclagem de nutrientes e, também, nos processos e propriedades físicas, químicas e biológicas do solo. O objetivo geral deste estudo foi avaliar os efeitos da aplicação de herbicidas em uma área de plantio de acácia-negra (Acacia mearnsii De Wild.). Para tal, o trabalho foi dividido em três capítulos. No primeiro capítulo, o objetivo foi avaliar o comportamento da meso e macrofauna epiedáfica sob a influência de diferentes tipos e intensidades de aplicação de herbicidas sobre o solo, por meio da análise de componentes principais (ACP). O estudo foi desenvolvido na Fundação Estadual de Pesquisa Agropecuária (Fepagro-Unidade Florestas), no município de Santa Maria/RS. Os tratamentos foram dispostos no delineamento blocos ao acaso, com quatro repetições por tratamento, totalizando 64 unidades experimentais, nas quais foram instalados dois pontos de coleta por unidade través do método PROVID de captura da meso e macrofauna epiedáfica. Os herbicidas utilizados foram Glyphosate (4,0 l ha-1), Imazapyr (3,0 l ha-1), Oxyfluorfen (4,0 l ha-1) e Pendimethalin (3,0 l ha-1), além de roçada manual e testemunha sem herbicida. As coletas foram relaizadas nas quatro estações do ano (inverno, primavera, verão e outono). Dos índices faunísticos calculados, a riqueza média de grupos taxonômicos variou entre 5,2 no inverno e 9,3 no verão. O índice de diversidade de Shannon (H) foi semelhante entre todos os tipos e intensidades de aplicação dos herbicidas testados. Este índice (H) diferenciou-se somente entre as estações do ano, variando entre 0,58 (primavera) e 1,21 (verão). A ACP entre as variáveis resposta e as variáveis explicativas não separou claramente a formação de componentes (grupos taxonômicos) influenciados significativamente pelo tipo e intensidade de aplicação dos herbicidas. Contudo, na ACP com variáveis suplementares explicativas para os quatro grupos taxonômicos mais representativos (Araneae, Orthoptera, Collembola e Hymenoptera), observou-se que a densidade de organismos no grupo constituído por colêmbolos é fortemente associada com à precipitação e na época da primavera, enquanto que formigas, ortópteros e aranhas têm sua densidade melhor explicada pela variável temperatura. Os diferentes herbicidas, bem como a intensidade de aplicação destes sobre o solo não exerceram efeitos negativos sobre os parâmetros biológicos avaliados no estudo, estando a diversidade e a densidade da meso e macrofauna epiedáfica condicionada apenas às variações estacionais ao longo do ano. O estudo abordado no segundo capítulo teve por objetivo avaliar, também, a influência de diferentes tipos e intensidades de aplicação de herbicidas sobre atributos físicos do solo, como densidade; macro, micro e porosidade total do solo; e diâmetro médio de agregados do solo (DMG). A base experimental de campo neste estudo foi a mesma do estudo desenvolvido no capítulo um. Foram realizadas duas coletas (antes do plantio das mudas e após todas as aplicações dos herbicidas). Duas amostras de solo foram coletadas na linha e duas na entrelinha de plantio das mudas. Os resultados obtidos na segunda coleta mostraram não haver diferença significativa entre os parâmetros avaliados. Para densidade do solo, os maiores valores foram constatados nos tratamentos sem aplicação de herbicidas (1,38 Mg m-3 na condição de roçada manual e 1,32 Mg m-3 na testemunha). Para macro, micro e porosidade total do solo os valores foram semelhantes entre si, para todos os tipos de herbicidas testados, assim como para o DMG dos agregados do solo. Não houve influência direta dos herbicidas sobre os atributos físicos do solo, uma vez que a matocompetição existente na área de estudo foi parcialmente controlada, principalmente na entrelinha de plantio das mudas, o que pode ter contribuído para a manutenção da estrutura física do solo neste local. Na linha de plantio, houve uma rápida reacomodação das partículas do solo por ação das raízes das mudas. O terceiro capítulo aborda o estudo que teve por objetivo avaliar a influência da aplicação de herbicidas sobre a associação simbiótica entre bactérias do gênero Rhizobium e o sistema radicular de mudas de acácia-negra, cultivadas em vasos plásticos, sob condições ambientais controladas em casa de vegetação. O estudo foi estabelecido no delineamento blocos ao acaso, com quatro repetições e dez plantas por tratamento, que estiveram constituídos pelos mesmos herbicidas e dosagens mencionadas no capítulo um, além de um tratamento com ausência de herbicida (testemunha). Os resultados neste estudo mostraram diferenças significativas entre os tratamentos para a variável biomassa seca de nódulos rizóbicos no sistema radicular de mudas de acácia-negra. Todos os herbicidas aplicados ao substrato dos vasos induziram à formação de nódulos rizóbicos, com destaque para o herbicida Oxyfluorfen (0,532 g planta-1), que apresentou um ganho em biomassa de nódulos de 128,3% com relação à testemunha (0,233 g planta -1). Exceto para Glyphosate, as correlações entre a biomassa de nódulos e as variáveis: altura, biomassa da parte aérea e biomassa radicular, foram todas positivas e significativas. Desse modo, a aplicação de herbicidas no microambiente avaliado neste estudo não exerceu influência negativa sobre os componentes físicos e biológicos (campo), assim como sobre o componente microbiológico avaliado (casa de vegetação).

Conselho Nacional de Desenvolvimento Científico e Tecnológico / This study aimed to describe the wood anatomy of ten species of the former genus Acacia Mill., as well as to conduct a quantitative agglomerative analysis with 25 species of the same genus, in order to recognize wood anatomical features of diagnostic value to the genera segregated from Acacia Mill. in 2005. The following species were investigated and described, according to IAWA Committee: Acacia acuminata A. Gray, Acacia cambagei R.T. Baker, ex Baker, Acacia harpophylla F. Muell. ex Benth., Acacia koa A. Gray, Acacia rhodoxylon Maiden, Acacia richii A. Gray, Senegalia martiusiana (Steud.) Seigler e Ebinger, Vachellia collinsii Saff., Vachellia nilotica (L.) P. J. H. Hurter e Mabb., e Vachellia planifrons (Wight e Arn.) Ragup., Seigler, Ebinger e Maslin. To the Cluster analysis, anatomical data of another 15 species were collected from the literature. All species share the following features of large occurrence in Fabaceae: diffuse-porous wood; simple perforation plates; vestured intervessel pits; paratracheal parenchyma; libriform fibers; and homogeneous rays. The presence of septate fibers allows to distinguish all the studied species of Senegalia Raf. The occurrence of conspicuous large rays, conjugated with abundant axial parenchyma allows to set apart all Vachellia species from the seven ones, that belongs to the genus Acacia Mill. / Este trabalho teve por objetivo a descrição anatômica de dez espécies de madeira do antigo gênero Acacia Mill., bem como a realização de uma análise quantitativa aglomerativa com dados de 25 espécies do mesmo gênero, com vistas a contribuir para o melhor conhecimento taxonômico, além de reconhecer, na estrutura do lenho, caracteres qualitativos e quantitativos de valor diagnóstico para os táxones segregados em 2005, a partir deste gênero botânico. As descrições basearam-se nas recomendações do IAWA Committee: Acacia acuminata A. Gray, Acacia cambagei R.T. Baker, ex Baker, Acacia harpophylla F. Muell. ex Benth., Acacia koa A. Gray, Acacia rhodoxylon Maiden, Acacia richii A. Gray, Senegalia martiusiana (Steud.) Seigler e Ebinger, Vachellia collinsii Saff., Vachellia nilotica (L.) P. J. H. Hurter e Mabb., e Vachellia planifrons (Wight e Arn.) Ragup., Seigler, Ebinger e Maslin. Na análise de Cluster foram utilizadas as espécies do presente estudo mais outras 15 colhidas na literatura. Todas as espécies apresentam os seguintes caracteres de ampla ocorrência em Fabaceae: porosidade difusa; placas de perfuração simples; elementos vasculares com pontoações ornamentadas; parênquima paratraqueal; fibras libriformes; e raios homogêneos. A presença de fibras septadas permite distinguir as espécies de Senegalia Raf. das demais. Por sua vez, a ocorrência de raios conspícuos, e a abundância de parênquima axial em Vachellia Wight e Arn. permite excluí-la das sete espécies do gênero.

Five techniques were used to predict the potential biogeography of the four alien plant species, Acacia longifolia, Acacia mearnsii, Opuntia ficus-indica and Solanum sisymbrifolium. Prediction was based on five environmental factors, median annual rainfall, co-efficient of variation for rainfall, mean monthly maximum temperature for January, mean monthly minimum temperature for July and elevation. A geographical information system was used to manage the data and produce the predictive maps. The models were constructed with presence and absence data and then validated by means of an independent data set and chisquared tests. Of the five models used, three (the range, principal components analysis and discriminant function analysis) were linear while the other two (artificial neural networks and fuzzy logic) were non-linear. The two non-linear techniques were chosen as a plant's response to its environment is commonly assumed to be non-linear. However, these two techniques did not offer significant advantages over the linear methods. The principal components analysis was particularly useful in ascertaining the variables that were important in determining the distribution of each species. Artifacts on the predictive maps were also proved useful for this purpose. The techniques that produced the most statistically accurate validation results were the artificial neural networks (77% correct median prediction rate) and the discriminant function analysis (71% correct median prediction rate) while the techniques that performed the worst were the range and the fuzzy classification. The artificial neural network, discriminant function analysis and principal component analysis techniques all show great potential as predictive distribution models.

Debarking of Acacia mearnsii in South Africa has been conducted using mainly manual systems. Labour shortages and reliability of these systems has caused interest in alternative systems that might be able to debark A. mearnsii. The aim of the research is to compare three mechanised debarking technologies used to debark A. mearnsii. Research trials were conducted on the Demuth, Hyena and Hypro debarkers that would form part of semi-mechanised harvesting systems. The debarking technologies were analysed and compared in terms of productivity per productive machine hour (PMH), debarking quality, system costs and the quality of the bark that was produced. Furthermore, the effect that tree volume, strippability and form have on each of the debarking technologies was determined. The debarking technologies were affected by each of the factors researched. Decreasing tree form had a negative effect on the productivity of each of the technologies. An increase in strippability class (strengthening wood-bark bond strength) caused a decrease in the productivity of each of the machines. An increasing tree volume had a positive effect on the productivity for the three debarking technologies. After the debarking had taken place, samples of bark were analysed at a laboratory to determine if it was acceptable for the processing facilities. Each of the debarking technologies produced bark of varying dimensions, but they were all found to be acceptable. The system costs of the three debarking technologies were compared to a manual system cost at tree volumes of 0.1m³, 0.15m³ and 0.2m³. The Demuth debarker had the best system cost for a tree size of 0.1m³, while the manual system was best for tree volumes 0.15m³ and 0.2m³. The Demuth, Hyena and manual system costs were very similar for each of the tree volumes, with the Hypro being a little higher.

The gum arabic belt in Sudan plays a significant role in environmental, social and economical aspects. The belt has suffered from deforestation and degradation due to natural hazards and human activities. This research was conducted in North Kordofan State, which is affected by modifications in conditions and composition of vegetation cover trends in the gum arabic belt as in the rest of the Sahelian Sudan zone. The application of remote sensing, geographical information system and satellites imageries with multi-temporal and spatial analysis of land use land cover provides the land managers with current and improved data for the purposes of effective management of natural resources in the gum arabic belt. This research investigated the possibility of identification, monitoring and mapping of the land use land cover changes and dynamics in the gum arabic belt during the last 35 years. Also a newly approach of object-based classification was applied for image classification. Additionally, the study elaborated the integration of conventional forest inventory with satellite imagery for Acacia senegal stands. The study used imageries from different satellites (Landsat and ASTER) and multi-temporal dates (MSS 1972, TM 1985, ETM+ 1999 and ASTER 2007) acquired in dry season (November). The imageries were geo-referenced and radiometrically corrected by using ENVI-FLAASH software. Image classification (pixel-based and object-based), post-classification change detection, 2x2 and 3x3 pixel windows and accuracy assessment were applied. A total of 47 field samples were inventoried for Acacia senegal tree’s variables in Elhemmaria forest. Three areas were selected and distributed along the gum arabic belt. Regression method analysis was applied to study the relationship between forest attributes and the ASTER imagery. Application of multi-temporal remote sensing data in gum arabic belt demonstrated successfully the identification and mapping of land use land cover into five main classes. Also NDVI categorisation provided a consistent method for land use land cover stratification and mapping. Forest dominated by Acacia senegal class was separated covering an area of 21% and 24% in the year 2007 for areas A and B, respectively. The land use land cover structure in the gum arabic belt has obvious changes and reciprocal conversions between the classes indicating the trends and conditions caused by the human interventions as well as ecological impacts on Acacia senegal trees. The study revealed a drastic loss of Acacia senegal cover by 25% during the period of 1972 to 2007.The results of the study revealed to a significant correlation (p ≤ 0.05) between the ASTER bands (VNIR) and vegetation indices (NDVI, SAVI, RVI) with stand density, volume, crown area and basal area of Acacia senegal trees. The derived 2x2 and 3x3 pixel windows methods successfully extracted the spectral reflectance of Acacia senegal trees from ASTER imagery. Four equations were developed and could be widely used and applied for monitoring the stand density, volume, basal area and crown area of Acacia senegal trees in the gum arabic belt considering the similarity between the selected areas. The pixel-based approach performed slightly better than the object-based approach in land use land cover classification in the gum arabic belt. The study come out with some valuable recommendations and comments which could contribute positively in using remotely sensed imagery and GIS techniques to explore management tools of Acacia senegal stands in order to maintain the tree component in the farming and the land use systems in the gum arabic belt.

The present study was conducted in Umfakarin natural forest reserve, South Kordofan, Sudan. The main objective was to investigate the possibility of managing Acacia seyal Del. variety seyal for the production of gum talha. Three stand densities (strata), namely dense, medium, and slight, were distinguished based on the number of trees per hectare. During the sampling phase, the study adopted the method of identifying the competitors (neighboring trees) from the subject one (trees selected for gum production experiments). From the three stand densities, a total of 482 subject trees, covering variable diameter ranges (d= 9-11.5, 13.5-16, 18-20.5 and above 21 cm) were selected, based on the diameter at 0.25 m height (d0.25). In each stratum, competitor trees were identified within a radius equal to the height of subject tree multiplied by a factor (1.25). The diameter at breast height, height to crown base, height, crown radii, and tree coordinates were measured for each of the subject trees and its competitors. Subject trees were exposed to tapping on first of October, the fifteenth of October, and the first of November, using local tools (Sonki and Makmak). Additionally, untapped trees were used as controlling-variables. The initial gum collection was completed fifteen days after the tapping, while the subsequent (7-9 pickings) were done at an interval of fifteen days. Six stand height functions were tested and the results illustrated that the Michailow stand height function was suitable for predicting the height of Acacia seyal in Umfakarin natural forest. The predictive ability of this height function ranged from 19.3% to 24%. The volume function used in this study was able to predict the volume of standing trees with more than 92 percent accuracy. Competition among trees of Acacia seyal was assessed in terms of competition indices. Eight competition indices were quantified using the CroCom program. The relationship between these indices and tree dimensions (diameter at breast height, height and crown diameter) was tested using logarithmic models. Among these indices, the Hegyi_2 index is considered a suitable index to be applied for estimating the degree of competition in natural stands of A. seyal of dense stratum when using diameter at breast height as a predictor. About 70% of the total variability is explained by this logarithmic model. Gum yielded by each subject tree per season was obtained by summing up the gum samples collected from all pickings. Gum production per unit area was also determined. Regression tree, general linear model (GLM) and logistic regression techniques were used for analyzing the obtained data. The results of the study indicated that the gum yield is independent of stand density. Tapping has influence on gum yield. Trees tapped by sonki on the first of October at medium stand density have the highest gum with an average value of about 56 g/tree/season. Significant difference (p = 0.021) was detected between two groups of dates; the first of October and first of November in medium stand density. The results also revealed that the most important variable influencing gum production was found to be diameter at breast height with 23.95 cm threshold. Between 41-53 percent of subject trees produce gum less than 50 g/season. The results indicated that A. seyal species produces a very low quantity of gum talha (3.6-4.8 kg/ha) and for economic reasons, its tapping is not recommended. The findings of the regression analysis revealed to a model which could be used to estimate the yield of gum talha from A. seyal natural stands in the Umfakarin forest, South Kordofan, Sudan. Conducting experiments on the production of gum talha in permanent plot trials in different climatic regions of the Sudan is highly recommended.

Syftet med detta examensarbete var att öka reaktiviteten hos förhydrolyserad kraftmassa genom att använda tidigare förhydrolysat och svavelsyra under förhydrolysen. Först bestämdes den kemiska sammansättningen av två olika vedråvaror (Acacia crassicarpa och Eucalyptushybrider) för att observera och korrelera med förhydrolysprocessen. Därefter studerades effekten av att för förhydrolyskraftkokning använda vatten, förhydrolysat och svavelsyra med olika koncentration under förhydrolysen vilket korrelerades med avlägsnandet av pentosan, utbyte, viskositet, kappanummer och ljushet. Därefter valdes en av vardera syrabaserad förhydrolyskraftmassa att blekas helt till dissolvingmassa för bestämning av Fock-reaktivitet, vilket jämfördes mot den vattenbaserade förhydrolysen som referens. Den slutliga kvaliteten på de olika förhydrolyskraftmassorna studerades också. Detta examensarbete visade att användandet av förhydrolysat och svavelsyra kan ge högre Fock-reaktivitet jämfört med vatten under liknande processförhållanden. Däremot gav syrabaserad förhydrolyskraftmassa lägre utbyte än vattenbaserad förhydrolyskraftmassa. Syrabaserad förhydrolyskraftkokning gav även lägre pentosanhalt, lägre halt extraktivämnen och lägre viskositetsvärden. Förhydrolysatbaserad förhydrolyskraftmassa hade värden mellan de som uppvisades av vattenbaserade- och svavelsyrabaserade förhydrolyskraftmassor. Dessutom hade förhydrolyskraftmassor från Eucalyptushybrider högre Fock-reaktivitet, lägre pentosanhalt, lägre halt extraktivämnen och högre viskositet än förhydrolyskraftmassor från Acacia crassicarpa. / The worldwide demand for dissolving pulp has been increasing significantly in Asia which is majorly produced from prehydrolysis kraft pulping and most of the prehydrolysis kraft pulp are consumed in viscose rayon production. Thus, it is interesting to have research in the process of prehydrolysis kraft pulping to make it a cleaner and more sustainable production. One of the most important qualities of prehydrolysis kraft pulp in viscose rayon is reactivity, which can lead to less chemical consumption and lower production cost. The aim of this research project is to increase the reactivity of prehydrolysis kraft pulp by using prehydrolysate and sulfuric acid during prehydrolysis cooking. Firstly, the wood chemical composition of two different hardwood species (Acacia crassicarpa and Eucalyptus hybrids) were determined and correlated with the prehydrolysis kraft pulping process. Secondly, prehydrolysis kraft cooking using water, prehydrolysate, and sulfuric acid with different concentration during prehydrolysis were studied and correlated with pentosan removal, yield, viscosity, kappa number, and brightness. Later, one of each acid based prehydrolysis kraft pulping were chosen to be proceed to fully bleached dissolving pulp for determining Fock reactivity which was compared to water prehydrolysis kraft pulping as the reference. The final quality of different prehydrolysis kraft pulps were also studied. From this research project, it showed that prehydrolysate and sulfuric acid prehydrolysis kraft pulp improved the Fock reactivity as compared to water prehydrolysis in similar pulping condition. However, acid based prehydrolysis kraft pulping gave lower yield than water prehydrolysis kraft pulping. Acid based prehydrolysis kraft cooking provided lower pentosan and extractive content, but lower viscosity values. Meanwhile, the prehydrolysate kraft pulp had the intermediate values between water and sulfuric acid prehydrolysis kraft pulping. In addition, Eucalyptus hybrids prehydrolysis kraft pulping had higher Fock reactivity, lower pentosan content, lower extractives, and higher viscosity than Acacia crassicarpa. To conclude, the more acidic prehydrolysis increased Fock reactivity with lower pulp yield, pentosan, extractive and viscosity.

Lignin är en av de vanligaste naturliga råvarorna på jorden och finns mestadels i trä. Nuförtiden är valoriseringen av lignin en av processutvecklingarna för teknologier inom massa- och pappersindustrin. Denna utveckling syftar till att öka värdet av lignin. Traditionellt förbränns genererat lignin, känt som tekniskt lignin, som bränsle i sodapannan som en del av svartlutskomponenter, och denna praxis är används kontinuerligt inom massa- och pappersindustrin. Syftet med detta examensarbete är att undersöka det tekniska ligninet från två specifika träslag, Acacia crassicarpa (Acra) och Eucalyptus Hybrids (Euca), för att öka kunskapen om det tekniska ligninet och hitta lämpliga tillämpningar för dessa råvaror i framtiden. I denna studie isolerades lignin från svartlut som genererats från två olika kokningsmetoder, kraftkokning- och kraftbased dissolvingkokning (KP och DP). Karakteriseringsmetoderna inkluderade molekylviktsfördelning (THF-SEC), analys av ligninets funktionella grupper med fosfor-31 Nuclear Magnetic Resonance (31P-NMR) kvantifiering och ligninets trukturella elementanalys via Two-Dimensional Heteronuclear Single Quantum Correlation NMR (2D-HSQC NMR). Utbytet erhållet från kraftkokning (KP) och kraftbased dissolvingkokning (DP) visade inga skillnader för samtliga prover och resultaten visas inom samma intervall (cirka 0,06-0,08 g/mol svartlut). Molekylviktsfördelningen för KP och DP-kokning ligger fortfarande inom intervallet för kraftlignin Mw (1500-5000 g/mol) och polydispersitetsindex (PDI) för KP hade ett högre värde än DP för båda typerna av undersökta råvaror. För de funktionella grupperna hade Eucalyptus Hybrids högre -OH-halt än Acacia crassicarpa oavsett kokningstyp. 31P-NMR kvantifieringsdata visade tydligt att KP-Euca innehöll den högsta halten av  alifatisk-OH (1,4 mmol/g). DP-Euca hade den högsta halten C5-kondenserad (2,5 mmol/g), medan den högsta mängden Guaiacyl-OH identifierades i DP-Acra (1,2 mmol/g). Fingeravtrycket av kopplingarna som kvantifierades från 2D-NMR HSQC visade att KP hade högre β-O-4', β-5' och β-β' interenhetskopplingar än DP. Dessutom hade Acacia crassicarpa en högre andel interenhetskopplingar än Eucalyptus Hybrids för båda kokmetoderna. De högsta β-O-4'-, β-5'- och β-β'-kopplingarna detekterades i KP-Acra med 3,4 %, 0,5 % respektiv 4,3 %. / Lignin is one of the most abundant natural raw materials on Earth and is mostly found in wood. Nowadays, the valorization of lignin is one of the continual process developments for technologies in the pulp and paper industry. This development is intended to increase the value of lignin. In the traditional approach, generated lignin known as technical lignin is burnt as fuel in the recovery boiler as part of black liquor components, and this practice is still common in the pulp and paper industry. The objective of this thesis work is to explore the technical lignin from specific wood species, Acacia crassicarpa (Acra) and Eucalyptus Hybrids (Euca), to emphasize the knowledge about the technical lignin and finding suitable application for the mentioned raw materials in the future. In this study, lignin was isolated from black liquor generated from two different cooking methods, kraft and kraft dissolving pulp cooking (KP and DP). The Characterization methods included molecular weight distribution by THF-SEC, lignin functional groups analysis via Phosphorus-31 Nuclear Magnetic Resonance (31P-NMR) quantification, and lignin structural elements analysis via Two-Dimensional Heteronuclear Single Quantum Correlation NMR (2D-HSQC NMR). The isolation yield obtained from kraft cooking (KP) and kraft dissolving pulp cooking (DP) did not have drastic differences for all the samples and therefore the results are within the same ranges (around 0.06-0.08 g/mol of black liquor). The molecular weight distribution values of KP and DP cooking are still within the range of kraft lignin Mw (1500-5000 g/mol) and the polydispersity index (PDI) of KP had a higher value than DP for both types of raw material investigated.  For the functional groups, Eucalyptus Hybrids had the higher -OH content than Acacia crassicarpa regardless of the cooking type. The 31P-NMR quantification data showed clearly that KP-Euca was the richest in Aliphatic-OH (1.4 mmol/g). DP-Euca had the greatest amount of C5-Condensed (2.5 mmol/g), while the highest amount of Guaiacyl-OH was identified in DP-Acra (1.2 mmol/g). The fingerprint of the linkages that was quantified from 2D-NMR HSQC showed that KP cooking had a higher β-O-4’, β-5’ and β-β’ interunit linkages than DP cooking. Furthermore, Acacia crassicarpa had a higher interunit linkages percentage than Eucalyptus Hybrids for both cooking methods. The highest β-O-4’, β-5’ and β-β’ linkages were detected in KP-Acra with 3.4 %, 0.5 %, and 4.3 % respectively.