Dissertations / Theses on the topic 'Slash Pine (Pinus Elliotti)'

P. elliottii Engelm. var. elliottii is an important exotic plantation species in Zimbabwe, where it is grown for saw-timber and resin production. Three progeny tests, originating from factorial matings between parents selected in plantations, were assessed at five, eight and 15 years. The objectives of the study were to characterise quantitative genetic variation in the population through the estimation of genetic parameters, and to use these parameters in combined indices to select for specified breeding objectives for P. elliottii in Zimbabwe. All traits of interest were under a reasonable degree of additive genetic control, and the magnitudes of nonadditive genetic variances were almost invariably much less than those of additive genetic variances. Narrow-sense heritabilities for growth traits, wood density and resin yield were moderate to high, ranging from 0.3 - 0.42; those for stem straightness and branching traits were lower, ranging between 0.10 and 0.25. Genetic correlations at each of the assessment ages were more variable; of most consequence for this study were the slight negative correlations between wood density and both stem diameter and volume, and the slight positive correlation between density and height. Age-age correlations for growth traits were high, indicating potential for early selection. Age-age correlations for other traits ranged from moderately negative to highly positive. Although statistically significant for many traits, genotype-environment interaction was judged by a number of criteria to be of little practical importance. No one site was the most efficient for selection across the range of traits for establishment at other sites; rather, a set of pooled parameters was estimated for application on sites typical of those on which commercial plantations of P. elliottii are established. Selection indices were constructed for four breeding objectives, representing differing assumptions about the relative importance of saw-timber and resin production. Indices for both direct and indirect selection were compared in terms of genetic gain, efficiency and accuracy, which were influenced by the differential weighting of traits in the breeding objective. The highest gains, efficiency and accuracies were for the breeding objective of saw-timber only; increasing the emphasis on resin production reduced each of these parameters, and also had a more adverse impact on wood density. For a breeding objective corresponding to or emphasizing saw-timber production, selection based on diameter or height at five years was best; selection on the latter has the advantage of maintaining wood density at around its present level. Should resin production also be important, resin yield or a correlated trait must be included in the index. Efficiencies of indirect selection were highest at five years, regardless of the breeding objective or selection criteria considered. The lack of economic information was a considerable hinderance in conducting these analyses. The construction of more complete indices, incorporating information from all siblings represented in the factorial mating design, was also investigated for the breeding objective of saw-timber production. These indices were compared in terms of gain and accuracy, and their effect on population structure in the subsequent generation. Selection based on the most complete index resulted in the greatest gain and accuracy, but also in the greatest reduction in additive genetic variance in the next generation. These results highlight the dilemma facing breeders charged both with achieving gains in the short term and maintaining diversity over the longer term. Breeding strategies which facilitate differential intensities of selection and breeding, and the maintenance of a large effective population size, are seen as the best means to resolve these conflicting demands; some implications for the breeding population of P. elliottii in Zimbabwe are discussed.

Orientador: Ananda Virginia de Aguiar
Abstract: Exotic forest species have been introduced in Brazil in order to promote improvements in socioeconomic development and help to reduce the pressure caused to native forests. With growing demand for these species, research on genetic improvement has increased to find new, more productive germplasm and preferably in less time. Two species were used in the study: slash pine (Pinus elliottii Engelm. var. elliottii) and radiata pine (Pinus radiata D. Don). The first part of the study had the purpose to identify the stability, adaptability, productivity and genetic parameters, in addition to selection gain and genetic divergence in slash pine open pollinated second generation progenies considering phenotypic trait. Two tests were established, one in Ponta Grossa-PR with 24 progenies and one in Ribeirão Branco-SP with 44 progenies, both in Brazil, to identify the most productive genotypes for commercial planting areas in both sites. There was significant variation (p<0.01) among progenies for growth and form traits. The high coefficients of genetic variation for wood volume (14.31% to 16.24% - Ribeirão Branco-SP and 31.78% to 33.77% - Ponta Grossa-PR) and heritability (0.10 to 0.15 – Ribeirão Branco-SP and 0.36 to 0.48 – Ponta Grossa-PR) have shown low environmental influence on phenotypic variation, which is important for the prediction of genetic gain by selecting and confirming genetic potential in both places, especially Ponta Grossa. The effect of genotype x environment interact... (Complete abstract click electronic access below)
Resumo: Espécies exóticas de Pinus foram introduzidas no Brasil para promoverem o crescimento socioeconômico do país e ajudar na redução da pressão causada pelo uso de florestas nativas Com a crescente demanda por essas espécies, pesquisas em melhoramento genético tem aumentado na busca de novos germoplasma mais produtivos em menor tempo. Duas espécies foram utilizadas no presente trabalho: Pinus elliottii Engelm. var. elliottii e Pinus radiata D. Don. A primeira parte do trabalho teve a finalidade de identificar a estabilidade, a adaptabilidade, a produtividade e os parâmetros genéticos, além do ganho de seleção e diversidade genética em progênies de polinização aberta de segunda geração de P. elliottii var. elliottii considerando os caracteres fenotípicos. Foram estabelecidos dois testes, um em Ponta Grossa-PR com 24 progênies e outro em Ribeirão Branco-SP com 44 progênies visando identificar os genótipos mais produtivos para áreas de plantio comercial em ambos locais. Foi observada variação significativa (p<0,01) entre as progênies para os caracteres de crescimento e alguns caracteres de forma. Os altos coeficientes de variação genética para volume de madeira (14,31% a 16,24% - Ribeirão Branco e 31,78% a 33,77% - Ponta Grossa) e herdabilidade (0,10 a 0,15 – Ribeirão Branco e 0,36 a 0,48 – Ponta Grossa) mostraram baixa influência do ambiente na variação fenotípica, o que é importante para a predição do ganho genético mediante a seleção e confirmam potencial genético em ambos os loc... (Resumo completo, clicar acesso eletrônico abaixo)
Doutor

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Espécies exóticas de Pinus foram introduzidas no Brasil para promoverem o crescimento socioeconômico do país e ajudar na redução da pressão causada pelo uso de florestas nativas Com a crescente demanda por essas espécies, pesquisas em melhoramento genético tem aumentado na busca de novos germoplasma mais produtivos em menor tempo. Duas espécies foram utilizadas no presente trabalho: Pinus elliottii Engelm. var. elliottii e Pinus radiata D. Don. A primeira parte do trabalho teve a finalidade de identificar a estabilidade, a adaptabilidade, a produtividade e os parâmetros genéticos, além do ganho de seleção e diversidade genética em progênies de polinização aberta de segunda geração de P. elliottii var. elliottii considerando os caracteres fenotípicos. Foram estabelecidos dois testes, um em Ponta Grossa-PR com 24 progênies e outro em Ribeirão Branco-SP com 44 progênies visando identificar os genótipos mais produtivos para áreas de plantio comercial em ambos locais. Foi observada variação significativa (p<0,01) entre as progênies para os caracteres de crescimento e alguns caracteres de forma. Os altos coeficientes de variação genética para volume de madeira (14,31% a 16,24% - Ribeirão Branco e 31,78% a 33,77% - Ponta Grossa) e herdabilidade (0,10 a 0,15 – Ribeirão Branco e 0,36 a 0,48 – Ponta Grossa) mostraram baixa influência do ambiente na variação fenotípica, o que é importante para a predição do ganho genético mediante a seleção e confirmam potencial genético em ambos os locais, especialmente Ponta Grossa. O efeito da interação genótipo x ambiente é simples. As progênies plantadas em um local poderão também ser plantadas no outro. Dentre essas as C-197, C-189-1, C-084-2 e C-032-2 são indicadas para plantações tanto na região estudada do estado de São Paulo quanto do Paraná. Apesar de um número maior de progênies em Ribeirão Branco, constatou-se o mesmo número de agrupamentos de progênies pelo método UPGMA e de otimização de Tocher em ambos os testes. Existe diversidade genética entre as progênies de P. elliottii. Para programas de melhoramento, recomenda-se o cruzamento entre progênies de grupos divergentes para aumentar a variação genética, e consequentemente, o ganho genético nas gerações subsequentes, sem esquecer de se levar em consideração a performance do caráter de interesse. O objetivo do trabalho em P. radiata foi relacionar os resultados de características da madeira obtidas a partir de dois métodos Pilodyn e SilviScan visando validar uma metodologia eficiente para fenotipagem de um maior número de amostras. Um teste com 30 progênies de P. radiata foi estabelecido em Flynn na Austrália. As características avaliadas foram densidade da madeira, o ângulo microfibrilar e o módulo de elasticidade. A correlação genética e fenotípica entre os caracteres da madeira obtidas a partir dos dois métodos e a herdabilidade individual no sentido restrito foram estimadas. Os dados de Pilodyn apresentaram alta herdabilidade e alta correlação genética e fenotípica entre densidade de madeira e moderada com ângulo microfibrilar e módulo de elasticidade. Os resultados confirmam que o Pylodyn é um efetivo método indireto e rápido para avaliação de parâmetros genéticos para caracteres de qualidade madeira em P. radiata.
Exotic forest species have been introduced in Brazil in order to promote improvements in socioeconomic development and help to reduce the pressure caused to native forests. With growing demand for these species, research on genetic improvement has increased to find new, more productive germplasm and preferably in less time. Two species were used in the study: slash pine (Pinus elliottii Engelm. var. elliottii) and radiata pine (Pinus radiata D. Don). The first part of the study had the purpose to identify the stability, adaptability, productivity and genetic parameters, in addition to selection gain and genetic divergence in slash pine open pollinated second generation progenies considering phenotypic trait. Two tests were established, one in Ponta Grossa-PR with 24 progenies and one in Ribeirão Branco-SP with 44 progenies, both in Brazil, to identify the most productive genotypes for commercial planting areas in both sites. There was significant variation (p<0.01) among progenies for growth and form traits. The high coefficients of genetic variation for wood volume (14.31% to 16.24% - Ribeirão Branco-SP and 31.78% to 33.77% - Ponta Grossa-PR) and heritability (0.10 to 0.15 – Ribeirão Branco-SP and 0.36 to 0.48 – Ponta Grossa-PR) have shown low environmental influence on phenotypic variation, which is important for the prediction of genetic gain by selecting and confirming genetic potential in both places, especially Ponta Grossa. The effect of genotype x environment interaction is simple. Progenies planted in one site can also be planted in the other. Among these C-197, C-189-1, C-084-2 and C-032-2 progenies are suitable for plantations in both studied region of São Paulo and Paraná. Although larger number of progenies in Ribeirão Branco, it was found the same number of clusters through UPGMA and Tocher methods in both tests. There is genetic diversity among slash pine progenies. For breeding programs, it is recommended to cross progenies between different groups to increase genetic variation, and consequently the genetic gain in subsequent generations, not forgetting to take into account the performance of interest trait. The objective of the study in Radiata pine was relate wood quality traits obtained from two methods Pilodyn and SilviScan to validate an efficient phenotyping methodology for a greater number of samples. A test with 30 progenies of Radiata pine was established in Flynn Australia. The evaluated traits were wood density, microfibril ange and modulus of elasticity. Genetic and phenotypic correlation between traits of wood quality obtained from two methods and narrow-sense individual heritability were estimated. The Pilodyn data showed high heritability and high genetic and phenotypic correlation between wood density and moderate with microfibril angle and modulus of elasticity. The results confirm that the Pylodyn is an effective indirect and rapid method for evaluation of genetic parameters for wood quality traits in Radiata pine.

A high extractive-content temperate conifer wood (Pinus elliottii) was examined as a pulpwood source by organosolv pulping. Particularly, the behavior of the resin- and fatty acids during the lignin solvolysis process was studied in detail. For this purpose the resin-and fatty acids were characterized in the wood, and after pulping trials in order to reveal their fate during pulping, using catalyzed 80% aqueous alcohol (methanol) as solvent. Wood extractives were removed by both methanolic cold maceration and Soxhlet extraction techniques. The resin-and fatty acid fractions thus collected were saponified and/or methylated and characterized by gas liquid chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). No significant differences were found in regard to extraction efficiencies between the two types of cold extractions. Furthermore, there was no significant difference between these two types of cold extractions in comparison with the procedure described by TAPPI standard T 204 os-76. Pulping experiments were performed at 205°C for periods of 5, 20, 40, and 60 min. Lignins, which precipitated on cooling of the black liquor (Lignin fraction I), were set aside for further extractions and chemical analyses. The molecular weight distribution of these lignins was determined by size exclusion chromatography on an HPLC and their quantity was determined either gravimetrically or volumetrically. Precipitated Lignin Fraction I, suspected of containing some adsorbed extractives and some fiber fragments, was transferred to a tared crucible. The lignin and extractives were sequentially dissolved by using tetrahydrofuran (THF), acetone and methanol. This solution was evaporated, the residue redissolved in methanol-water (80:20) and the solution liquid-liquid extracted with diethyl ether in a separatory funnel followed by methylation prior to GC and GC-MS analysis. Quantification of the resin- and fatty acids in the wood and those recovered after organosolv pulping was performed using an internal standard (methyl heptadecanoate) added prior to the extraction steps. The extractives dissolved in the black liquor were isolated by a ternary liquid-liquid extraction scheme using diethyl ether, methylated with fresh diazomethane, and the resin- and fatty acids methyl esters characterized by GC and GC-MS. The extractives present in the pulp were isolated (removed) by a Soxhlet extraction procedure with methanol and" the resin- and fatty acids fractions characterized as above. Resin- and fatty acids surviving the high-temperature pulping process, were found mainly in the black liquor. After the 60 min cook, the black liquor contained 78.1% and 71.6% of resin- and fatty acids, respectively, while the pulp retained 11.7% and 8.2%, respectively of the extractives originally present in wood. "Lignin fraction I" adsorbed 10.2% and 20.2% of the resin- and fatty acids, respectively. Contrarily, if all of the lignin is precipitated (Lignin fraction II). prior to liquid/liquid extraction of the black liquor with diethyl ether, 98% and 60.4% of the resin- and fatty acids co-precipitate with the lignin and 2.0% and 39.6%, respectively, remain dissolved in the aqueous filtrate. Industrial organosolv lignin isolated after solvent pulping of pine was thus shown to contain most (98%) of the resin acids and 39.6% of the fatty acids normally found in pines. Although not tested, it is supposed that lignins isolated by precipitation from the black liquor after organosolv pulping of other species cannot be considered as "pristine lignins" as described hitherto in the technical literature, since such lignins are heavily contaminated by the extractives of the wood species. In light of these findings all data on chemical and physical characterization of organosolv lignins and their reactivity will have to be reexamined and reassessed to remove the effect of the extractives as contaminants.
Forestry, Faculty of
Graduate

South Florida slash pine (Pinus elliottii var. densa) is the southernmost pine species in the United States and the foundation species of the globally endangered pine rockland communities in south Florida. To test if slash pine produces annual growth rings in the Lower Florida Keys, we counted the number of rings on samples collected from the North Big Pine Key site (NBP), which contained a fire scar from a known wildfire and a known date for hurricane-induced tree mortality (2006 or 2007). In addition, a crossdated tree-ring chronology (1871–2009) was developed from living trees and remnant wood found at the site and compared to divisional climate data to determine how the regional climate regime influences radial growth. Our analyses demonstrated that slash pine forms anatomically distinct, annual growth rings with the consistent year-to-year variability necessary for rigorous dendrochronological studies. Response-function and correlation analysis showed that annual growth of slash pine at NBP is primarily influenced by water availability during the growing season. However, no significant correlations were found between tree growth and the Atlantic Multidecadal Oscillation or the El Niño-Southern Oscillation. Our study reveals the potential of producing high-quality dendrochronological data in southern Florida from slash pine, which should prove useful in further studies on fire history and tree phenology and for assessing the projected impacts of impending climate change on the fragile pine rockland community.

Ectomycorrhizas generally improve seedling mineral nutrition and growth, so I hypothesized that decline of the Florida native pine variety Pinus elliottii var. densa Little & Dorman is related to deficiency of appropriate ectomycorrhizal (ECM) fungi in the pine's native flatwoods. At Archbold Biological Station I examined how quickly ECM fungi colonize P. elliottii var. densa seedlings and I compared the effect of local absence versus presence of adult pines on ECM colonization and pine seedling performance. Under controlled greenhouse conditions, I investigated how a wide range of ECM colonization and spread of extraradical mycelium throughout a large volume of relatively infertile, flatwoods soil enhance the mineral nutrition and growth of pine seedlings. In a field bioassay, I transplanted two-month-old pine seedlings to three flatwoods sites with low (4 pines/400 square m), medium (9 pines/400 square m), and high (19 pines/400 square m) adult pine densities. I subsequently excavated seedlings every two weeks for four-and-a-half months and determined their ECM colonization, response to shade, and response to surrounding grass density. Across all sites, pine seedlings in high shade had a higher mean chlorophyll concentration and lower stem dry weight than in full sun. Competition with grass reduced seedling survival and stem dry weight. Initial colonization was rapid and not different among sites, with 5.4 % of roots colonized 15 days after transplant. Pine seedlings had midpoint means of 29.5 %, 18.1 % and 21.3 % ECM root tips in low, medium and high adult pine density sites, respectively, suggesting that pine seedlings establishing in flatwoods encounter sufficient ECM fungi to support their growth, regardless of adult pine density. In a field experiment, I determined in the presence versus absence of adult pines if pine seedlings had higher ECM colonization and consequent improved survival, mineral nutrition, and growth. Within and beyond pine stands, I transplanted seedlings into intact or drilled, hyphae in-growth pipes buried in the ground. I placed autoclaved or fresh ECM root inoculum in two sets of intact pipes, and autoclaved inoculum in drilled pipes into which mycorrhizal hyphae could extend from the surrounding vegetation. Seven-and-a-half months after transplant, ECM hyphae had penetrated the drilled pipes and colonized pine seedlings, but roots from the surrounding vegetation also penetrated pipes. Extraneous roots reduced the survival of seedlings both within and beyond pine stands, but extraneous roots reduced seedling growth only beyond pine stands. Because percentage ECM root tips was higher in the presence (53 %) than in the absence (38.8%) of adult pines, pine stands might benefit the competitive ability of seedlings by increased ECM colonization and possibly by common mycorrhizal networks connecting seedlings to adults. Because beneficial effects of ECM in the field were small, I also examined ECM effects on pine seedlings in a greenhouse experiment. I manipulated ECM fungus colonization and the volume of flatwoods soil to which extraradical mycelium had access. In a small volume of soil (220 mL), fresh ECM root inoculum promoted the mycorrhizal colonization of seedlings versus those receiving autoclaved roots, but seedling growth and uptake of Mg, Ca, and Zn was lower with fresh than with autoclaved root inoculum. Growth and mineral nutrient uptake likely was enhanced by a pulse of nutrients from autoclaved roots, but for inoculated plants may have been reduced because of nutrient retention by saprotrophic microorganisms degrading fresh ECM roots and because of mineral nutrient retention by ECM fungi. Ectomycorrhizal seedlings with extraradical mycelium access to a large soil volume had higher mean chlorophyll concentration than those in a small soil volume. Weekly disturbance of the extraradical mycelium, however, reduced foliar contents of Mn, K, P, N, and Zn by one-third to one-half, and reduced needle dry weight of seedlings by one-third, demonstrating the importance of extraradical mycelium accessing a large volume of soil when it is nutrient-poor. My research demonstrates that ECM fungi are widespread in flatwoods and rapidly colonize pine seedlings. ECM fungus inocula are greater in the presence than in the absence of adult pines, and ECM or seedlings' connections to a common mycorrhizal network improve seedlings' belowground competitive ability. ECM especially enhance seedling mineral nutrition and growth when undisturbed, extraradical mycelium extends throughout a large volume of soil. Populations of Pinus elliottii var. densa might best regenerate in flatwoods if seedlings recruit near adult pines and where there is little competition for light, water, and mineral nutrients.

A study was conducted at the Savannah River Site near Aiken, SC to: 1) characterize the spatial patterns of soil and forest floor variables (moisture, pH, soil phosphate, forest floor and soil carbon and nitrogen, and soil available nitrogen), 2) assess the spatial patterns of the plant community, and 3) investigate spatial relationships among the variables and between the variables and woody vegetation. Spatial soil and litter samples were collected on five 0.25 hectare plots, and relationships were explored using Pearson's correlation tests, canonical correlation analysis, variogram modeling and kriging. The average range of spatial autocorrelation for the forest floor variables was >45 m, while that for soil variables was 12 m. Woody stem basal area exhibited spatial autocorrelation at ranges of less than 12 m, and was only weakly correlated with forest floor and soil resource patterns. Few strong spatial correlations among the forest floor and soil variables were observed. The means and variances of the variables were low, and differences in resource levels probably had little impact on the spatial pattern of vegetation. Results indicate a weak, differential effect of species group on litter quality, a weak relationship between large pine trees and soil nitrogen patterns, and a general homogeneity of the stands.
Master of Science

With increasing encroachment on natural communities by anthropogenic activity, it is important to understand the functions of natural ecosystems in an effort to conserve natural areas. A first-hand study of the population dynamics of South Florida Slash Pine (P. elliottii Engelm. var. densa) following a fire event provided insight to its recovery and dispersal following a fire. A natural fire (lightning-induced) occurred in the spring of 2000 at the T. Mabry Carlton, Jr. Reserve, Sarasota County, providing an opportunity to study aspects of slash pine in relation to fire. One objective of my research was to look at dispersal/recruitment conditions and slash pine dynamics in relation to fire. I looked at the varying degrees of tree mortality due to fire at different stands of slash pines. I also looked at the stands in terms of stand composition and spatial arrangement of surviving adults. Finally, I studied how variable seedling establishment and survival was between stands. Few inferences could be drawn between fire and these individual analyses; however, all analyses revealed that at the scale of this study, pine flatwoods are patchy. I also looked at the dispersal of slash pines following a fire event. I modeled my research after Ribbens et al. (1994) and Clark et al. (1998), who took a phenomenological approach to dispersal modeling. This approach involved using distances between adults and seeds/seedlings and fecundity of adults to create dispersal models based on maximum likelihood estimates (MLE). I found that, while I could predict a model within acceptable parameters for most of the stands, more data was needed to predict models that better fit the data. This finding, along with the fact that I recovered no seed data for analysis, suggests factors are contributing to dispersal and recruitment (e.g. cone-crop) that need to be accounted for in the future.

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Thesis (M.S.)--University of South Florida, 2003.
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Text (Electronic thesis) in PDF format.
ABSTRACT: With increasing encroachment on natural communities by anthropogenic activity, it is important to understand the functions of natural ecosystems in an effort to conserve natural areas. A first-hand study of the population dynamics of South Florida Slash Pine (P. elliottii Engelm. var. densa) following a fire event provided insight to its recovery and dispersal following a fire. A natural fire (lightning-induced) occurred in the spring of 2000 at the T. Mabry Carlton, Jr. Reserve, Sarasota County, providing an opportunity to study aspects of slash pine in relation to fire. One objective of my research was to look at dispersal/recruitment conditions and slash pine dynamics in relation to fire. I looked at the varying degrees of tree mortality due to fire at different stands of slash pines.
ABSTRACT: I also looked at the stands in terms of stand composition and spatial arrangement of surviving adults. Finally, I studied how variable seedling establishment and survival was between stands. Few inferences could be drawn between fire and these individual analyses; however, all analyses revealed that at the scale of this study, pine flatwoods are patchy. I also looked at the dispersal of slash pines following a fire event. I modeled my research after Ribbens et al. (1994) and Clark et al. (1998), who took a phenomenological approach to dispersal modeling. This approach involved using distances between adults and seeds/seedlings and fecundity of adults to create dispersal models based on maximum likelihood estimates (MLE). I found that, while I could predict a model within acceptable parameters for most of the stands, more data was needed to predict models that better fit the data.
ABSTRACT: This finding, along with the fact that I recovered no seed data for analysis, suggests factors are contributing to dispersal and recruitment (e.g. cone-crop) that need to be accounted for in the future.
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A produção de criogéis de celulose para adsorção de petróleo torna-se um estudo interessante, já que a celulose é uma fonte econômica, renovável, biodegradável e abundante no meio ambiente. Dentro deste contexto, o objetivo do presente trabalho foi desenvolver criogéis de celulose com capacidade de adsorção de petróleo e resistência mecânica. Para isso, nessecitou-se da utilização de tratamentos químicos como a silanização e a adição de hidróxido de sódio (NaOH) nas concentrações de 4 e 8% (m/m). Na silanização dois métodos foram estudados: a adição de metiltrimetoxisilano (MTMS) à suspenão de celulose e a deposição a vapor de MTMS no criogel. A suspensão de celulose foi obtida a partir de fibrilação mecânica de 1,5% (m/m) de celulose fibra longa não branqueada (FLNB) da espécie Pinus elliottii por 5 h a 2500 rpm. A suspensão foi então congelada a -80ºC por 24 h e então liofilizada a – 40ºC por 70 h. Diversos ensaios de caracterização foram realizados nos criogéis, entre eles: massa específica e porosidade, microscopia eletrônica de varredura por emissão de campo (MEV-FEG), difração de raios-X (DRX), índice de cristalinidade, espectroscopia de infravermelho com Transformada de Fourier (FTIR), compressão, hidrofobicidade, capacidade de adsorção e dessorção, cinéticas e isotermas de adsorção. Entre os métodos de silanização, a deposição a vapor de MTMS apresentou os maiores valores de capacidade de adsorção experimental homogênea (65,18 g.g-1) e heterogênea (68,42 g.g-1). Em relação à adição de NaOH, o criogel produzido com adição de 4% apresentou uma resistência à compressão 28% maior que o criogel sem tratamento. Com isso, o estudo do processo de adsorção foi realizado com o criogel produzido com 4% de NaOH e deposição a vapor de MTMS (FLNB-4D). A capacidade de adsorção experimental heterogênea e a resistência à compressão do criogel FLNB-4D foram de 21,80 g.g-1e 93,16 kPa, respectivamente. No estudo da cinética o modelo que mais se ajustou ao processo foi pseudossegunda ordem e para o estudo do equilíbrio de adsorção foi Langmuir. Por fim, conclui-se que o processo de adsorção de petróleo pelo criogel de celulose pode ser definido como fisissorção e ocorre em monocamada. Além de que, o criogel de celulose desenvolvido no presente trabalho apresenta-se adequado para a utilização na adsorção de petróleo.
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The production of cellulose cryogels for oil adsorption becomes an interesting study since cellulose is an economical, renewable, biodegradable and abundant source in the environment. Within this context, the aim of the present work was to develop cellulose cryogels with oil adsorption capacity and mechanical strength. The use of chemical treatments such as silanization and the addition of sodium hydroxide (NaOH) at concentrations of 4 and 8% (m/m) were used. In the silanization two methods were studied: the addition of methyltrimethoxysilane (MTMS) to cellulose suspension and the vapor deposition of MTMS in the cryogel. The cellulose suspension was obtained from mechanical fibrillation of 1.5% (w/w) unbleached long fiber cellulose (FLNB) of Pinus elliottii for 5 h at 2500 rpm. The suspension was then frozen at -80°C for 24 h and then freeze-drying at -40°C for 70 h. Various characterization assays were performed on the cryogels, including: specific mass and porosity, field emission scanning electron microscopy (FEG-SEM), X-ray diffraction (XRD), crystallinity index, Fourrier transform infrared spectroscopy (FTIR), compression, hydrophobicity, adsorption and desorption capacity, adsorption kinetics and isotherms. Among the silanization methods, the vapor deposition of MTMS presented the highest values of homogeneous (65.18 g.g-1) and heterogeneous (68.42 g.g-1) experimental adsorption capacity. About the addition of NaOH, 4% added cryogel exhibited a 28% higher compressive strength than untreated cryogel. Thus, the adsorption process was performed with cryogel produced with 4% NaOH and vapor deposition of MTMS (FLNB-4D). The heterogeneous experimental adsorption capacity and the compressive strength of the FLNB- 4D cryogel were 21.80 g.g-1 and 93.16 kPa, respectively. In the study of the kinetics, the model that best fitted the process was pseudosecond order and for the study of the adsorption equilibrium was Langmuir. Finally, it is concluded that the process of adsorption of oil by cellulose cryogel can be defined as physisorption and occurs in monolayer. In addition, the cellulose cryogel developed in the present work is suitable for use in the adsorption of petroleum.

The forest product industry is keenly interested in extending the normal planting season, as well as in the comparative field performance of standard nursery bare-root seedlings and containerized rooted cuttings. The effect of seasonal planting dates on survival, above and belowground biomass allocation, water relations, gas exchange attributes and foliar carbon isotope composition (δ13C) of two stock types of slash pine (Pinus elliottii Engelm.) were examined. Slash pine bare-root seedlings (BRS) and containerized rooted cuttings (CRC) were hand planted in September, November, January, March and April in three consecutive planting seasons (2000-2001, 2001-2002 and 2002-2003) on three sites with silt loam topsoils in southwestern Louisiana. First-year mean survival of CRC across all planting dates and sites was consistently high at 96 to 98%, whereas BRS survival was significantly (P < 0.0001) lower at 59 to 81% and highly variable among study sites and dates through three planting seasons. Generally, there was a negative relationship between soil moisture at the time of planting and first-year survival of BRS planted September through March in 2001-2002 and 2002-2003 planting seasons, whereas the opposite was observed only for BRS planted in April 2002 and 2003. Survival of CRC was affected very little by the variation in soil moisture. Containerized rooted cuttings had higher early above and belowground biomass, and height and diameter than did BRS. However, three years after planting the size differences between stock types disappeared or became negligible. Early size differences among trees planted September through March also decreased after three years, although September trees were tallest. Growth of the April-planted trees was poor compared to trees planted in other months. Late-planted April trees had higher δ13C values, and higher water-use efficiency in the first growing season compared to earlier planted trees. Differences in δ13C values among the planting dates disappeared in the second growing season. Net photosynthesis rates did not differ considerably between stock types or among planting dates in the second and third growing seasons. This study indicates that it is possible to extend the planting season to as early as September and as late as March by using CRC.

There has been an increased interest in characterizing and interpreting ecological heterogeneity over space and time in the past two decades. This is mainly due to the renewed recognition of the significance of heterogeneity in ecological theories. However, studies that have combined both spatial and temporal aspects of heterogeneity have been rare. A unified approach to define and quantify heterogeneity has also been lacking. Designed to overcome these problems, this study was conducted in a 40-year-old Pinus elliottii Engelm. forest at the Savannah River Site near Aiken, SC, USA with the following specific objectives: 1) to characterize the spatial patterns of soil and forest floor variables (moisture, pH, soil available nitrogen and phosphate, forest floor and soil carbon and nitrogen), 2) to examine the dynamics of these spatial patterns in response to two types of disturbance: whole-tree harvesting and girdling, and 3) to evaluate some of the current methods for quantifying ecological heterogeneity. In response to both disturbance treatments, spatial heterogeneity measured by sample variance showed a marked "increase and then decline" temporal pattern in soil moisture, soil available nitrogen and phosphorus. Similar patterns were not found in total soil C and N, and total litter C and N. Harvesting resulted in greater and more drastic changes in the variations of soil nutrients and water than did girdling. Despite the popularity of semivariogram analysis in recent ecological studies, the technique did not provide consistent results on patterns of heterogeneity in our system. A simulation experiment demonstrated that semivariogram analysis may suffer from many problems when it is used to characterize patchiness, one form of heterogeneity. The results from this study have a number of implications. First, spatial patterns of soil resources are high dynamic. The dynamics of patterns in soil resources may partly account for the weak correlation between vegetation and soil observed in ecological literature. Second, heterogeneity may be most effectively quantified by first identifying quantifiable components and then quantifying these components individually. A common pattern can be sought by comparing patterns of different components of heterogeneity for a given ecological property and by comparing patterns of different ecological variables for a given component of heterogeneity. Third, compared to surveys, field manipulative experiments can provide information that link patterns with ecological processes. As such, this study adds to ecological literature valuable information on temporal changes of soil heterogeneity following disturbance and conceptual advances in the quantification of ecological heterogeneity.
Ph. D.

Doutoramento em Biologia
Slash Pine (Pinus elliottii var. elliottii) and the hybrid (Pinus elliottii var. elliottii x Pinus caribaea var. hondurensis) have a great economic value due to their high growth ratio and resin production. Therefore, it is important to achieve a strategy to propagate this species and the hybrid more rapidly maintaining their characteristics. This project aims to preserve/enlarge the Pinus germplasm collection, provided by the company KLÓN, Innovative Technologies from Cloning, by micropropagation and cryopreservation techniques and analyze the putative changes (genetic stability) in micropropagated plants by flow cytometry, to study plant survival rates, growth and photosynthetic performance after acclimatization. In Chapter I, general aspects of the species and hybrid under study are presented, as well as a brief description of the breeding programs in Pinus spp. and the contribution that innovative techniques of in vitro propagation can give, leading to decades of anticipation on the breeding programs results. It was also described some major aspects to the different micropropagation and cryopreservation techniques, always presenting a review of current knowledge on the use of these techniques in the genus Pinus. Finally, the research objectives of this thesis are presented. Chapter II is dedicated to the application of a micropropagation protocol by proliferation of axillary shoots in the specie Pinus elliottii var. elliottii. This Chapter was divided in two sections. In section II.1 a protocol was optimized for large-scale P. elliottii micropropagation, which describes all the steps from disinfection and seed germination to the production of seedlings in vitro, which were used as explants for shoot induction. Various conditions for induction, shoot elongation and rooting were tested, and a protocol enabling the production of micropropagated plantlets 20 to 22 weeks after germination in vitro has been established. In section II.2 was performed the genetic and physiological characterization of P.elliottii plants micropropagated by the methodology developed in the previous section, in comparison with seedlings. The physiological performance of the plants was evaluated by determination of various parameters associated with photosynthesis and carbon metabolism, such as: chlorophyll a fluorescence; relative water content; gas exchange; pigment and carbohydrate contents. In turn, the genetic characterization was performed by analysis by flow cytometry of putative alterations in DNA content, ploidy level and in cell cycle dynamics. The results indicate that the developed micropropagation protocol for P. elliottii did not induce significative changes, both at physiological and genetic level, in the plants. Chapter III focuses on the optimization of a somatic embryogenesis process for the hybrid Pinus elliottii var. elliottii x Pinus caribaea var. hondurensis, from the initiation to the plants regeneration produced from somatic embryos. For initiation of embryogenic cultures of this hybrid, immature megagametophytes obtained from five open-pollinated plus trees were used as explants. To optimize the process, the effect of genotype in both the initiation and maturation, as the influence of different formulations of basal media and growth regulators in the various stages of the process were evaluated. Throughout the process was assessed the genetic stability of embryogenic masses with different time in culture, and at the end of the produced emblings, in comparison with the mother-trees needles. This protocol allows the production of emblings from somatic embryos not having been detected variability in the DNA content and ploidy level. Chapter IV is dedicated to the preservation of germplasm bank produced for the hybrid under study. Cryopreservation of embryogenic masses is beneficial not only for the preservation of germplasm during the breeding programs development, as well as to avoid the loss of the potential of the embryogenic masses. For the optimization of an embryogenic masses cryopreservation protocol using the slow freezing method, different variations were tested in pretreatments and in the duration of slow freezing step. Pretreatments to which the embryogenic tissue was subjected, did not compromise the maturation capacity of cryopreserved masses. On the contrary, cryopreservation had in some genotypes a beneficial effect. The optimized protocol allowed the regeneration of plants from cryopreserved masses and the process did not induce major genetic changes (embryogenic masses cryo and non cryopreserved were analyzed by flow cytometric). Finally, Chapter V presents the final conclusions of this PhD thesis, gathering the results of this thesis on the propagation and preservation methodologies for the species and hybrid in study and discussion this contribution to the state of art in this field. Future challenges for further research in these areas are presented in this Chapter.
Pinus elliottii var. elliottii e o híbrido, Pinus elliottii var. elliottii x Pinus caribaea var. hondurensis, têm um grande valor económico, devido à sua elevada taxa de crescimento e produção de resina. Surge assim a necessidade de desenvolver estratégias de propagação mais eficientes desta espécie e do híbrido, mantendo as suas características. Este estudo tem como objetivos preservar / aumentar o banco de germoplasma de Pinus, fornecido pela empresa KLÓN, Innovative Technologies from Cloning, utilizando técnicas de micropropagação e de criopreservação, analisar possíveis alterações na estabilidade genética das plantas micropropagadas através de citometria de fluxo, estudar a taxa de sobrevivência de plantas, crescimento e desempenho fotossintético após aclimatização. No Capítulo I foram abordados aspetos gerais da espécie e híbrido em estudo, assim como uma breve descrição dos programas de melhoramento em Pinus spp. e da contribuição que técnicas inovadoras de propagação in vitro podem dar levando a décadas de antecipação dos resultados dos respectivos programas de melhoramento. Foram também descritos alguns aspetos mais importantes relativos às diferentes técnicas de micropropagação e criopreservação existentes, apresentando sempre uma revisão do conhecimento atual sobre o uso destas técnicas no género Pinus. Para finalizar este capítulo, os objetivos de investigação desta Tese são apresentados. O Capítulo II é dedicado à aplicação de uma metodologia de micropropagação (por proliferação de rebentos axilares) da espécie Pinus elliottii var. elliottii. Este capítulo foi dividido em duas secções. Na secção II.1 foi otimizado um protocolo para micropropagação em larga escala de P. elliottii desde a desinfecção e germinação de sementes para a produção de plântulas in vitro. Estas por sua vez são utilizadas como explantes para a indução de rebentos. Foram testadas várias condições para a indução, alongamento e enraizamento de rebentos, tendo sido estabelecido um protocolo que permite a produção de plântulas micropropagadas 20 a 22 semanas após germinação in vitro. Na secção II.2 foi realizada a caracterização genética e fisiológica de plantas de P. elliottii micropropagadas pela metodologia desenvolvida na secção anterior, em comparação com plantas provenientes de sementeira. O desempenho fisiológico das plantas foi avaliado pela determinação de diversos parâmetros relacionados com a fotossíntese e o metabolismo de carbono, tais como a fluorescência de clorofila a, o teor relativo em água, as trocas gasosas, o teor de pigmentos e de carbohidratos. Por sua vez a caracterização genética foi realizada pela análise do conteúdo em DNA e nível de ploidia, e ainda as dinâmicas do ciclo célular, com recurso à citometria de fluxo. Os resultados obtidos indicam que o protocolo de micropropagação desenvolvido para P. elliottii não provoca alterações significativas tanto a nível fisiológico como genético nas plantas. O Capítulo III centra-se na otimização de um processo de embriogénese somática para o híbrido Pinus elliottii var. elliottii x Pinus caribaea var. hondurensis, desde a iniciação até à regeneração de plantas produzidas a partir de embriões somáticos. Para a iniciação de culturas embriogénicas deste híbrido foram utilizados como explantes megagametófitos imaturos obtidos a partir de polinização aberta de cinco árvores plus. Para a otimização do processo foi avaliado o efeito do genótipo tanto na iniciação como na maturação, tal como o influência de diferentes formulações de meios basais e reguladores de crescimento nas diversas fases do processo. Ao longo do processo foi avaliada a estabilidade genética das massas embriogénicas com diferentes tempos de cultura, e no final das plântulas produzidas, em comparação com as agulhas das árvores-mãe, concluindo-se que foi desenvolvido um protocolo que permite a produção de plantas provenientes de embriões somáticos não tendo sido detectada variabilidade ao nível de conteúdo em DNA e nível de ploidia. O Capítulo IV é dedicado à preservação do banco de germoplasma produzido para o híbrido em estudo. A criopreservação de massas embriogénicas é benéfica não só para a preservação de germoplasma durante o desenvolvimento de programas de melhoramento, como para evitar a perda do potencial embriogénico das massas. Para a otimização de um protocolo de criopreservação de massas embriogénicas pelo método de congelamento lento, foram testadas diferentes variações nos pré-tratamentos e na duração do passo de congelação lenta. Os pré-tratamentos a que o tecido embriogénico foi submetido não influenciaram negativamente a capacidade de maturação das massas criopreservadas, apresentando-se a criopreservação até em alguns genótipos com um efeito benéfico. O protocolo otimizado permitiu a regeneração de plantas a partir de massas criopreservadas, para as quais se comprovou que o processo não provocou alterações genéticas, através da análise por citometria de fluxo de massas embriogénicas crio e não criopreservadas. Finalmente, no Capítulo V são apresentadas as conclusões finais da Tese de Doutoramento, onde são realçados os avanços realizados como resultado desta tese nas metodologias de propagação e preservação para a espécie e híbrido em estudo. Neste capítulo são também apresentados os desafios futuros para a continuação da investigação nas áreas de propagação e preservação de Pinus.

The global paleoclimate archive is lacking in tropical dendrochronology studies as a result of limitations from inconsistent tree-ring production imposed by precipitation-driven seasonality. The slash pine, Pinus elliottii Engelm. var. densa, is the dominant canopy species of Big Pine Key (BPK) rocklands and has been shown to produce complicated, but distinct, ring structures; however, traditional dendrochronology studies have not established correlations between ring width measurements and major climate drivers controlling South Florida precipitation. My study utilized the carbon (δ13C) and oxygen (δ18O) isotope records in the α-cellulose component of tree-rings to extract information about the physiological responses of trees to climate and tropical cyclone activity. The δ13C measurements in the earlywood and latewood of four P. elliottii var. densa trees were used to build a chronology (1922-2005) and to distinguish annual growth from intra-annual density fluctuations (IADFs). Empirical orthogonal functions were used to determine individual response to precipitation, El Niño-Southern Oscillation (ENSO), and the Atlantic Multidecadal Oscillation (AMO). There is a distinct relationship between the δ13C values of cellulose and ENSO; however the nature (direct vs. inversely correlated) is temporally controlled by the prevailing phase of the AMO. The appearance of some IADFs coincide with the timing of El Niño winters occurring during the cool AMO phase, resulting in enriched δ13C values. The additional precipitation may encourage tree growth, but subsequent dry periods may slow growth and cause the tree to employ water-conservation strategies. Tree growth is influenced by the major climate drivers and the control they exert over the timing of precipitation; however, growth is ultimately controlled by the microenvironment surrounding individual trees. The δ18O and δ13C values of the latewood cellulose were compared to tropical cyclone activity occurring within a 100km radius of BPK. Tropical storms and depressions appeared as anomalously depleted values in the δ18O residual record, reflecting large amounts of tropical rain. The effects of hurricanes varied by storm; however, many of the major hurricanes (category 3-5) were preserved as an enrichments in the δ13C value of the following earlywood season. The application of stable isotope analyses greatly increases the breadth of paleoclimate information available from the trees.

Thesis (MScFor)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: Individual tree models, as opposed to stand models, have the potential to greatly improve sensitivity of forest growth models to changing conditions such as silvicultural amendments, irregular stand structures, etc. It was the purpose of this study to extend two sub-components of a European individual tree growth model to introduce individual tree growth modelling concepts in South Africa using Pinus elliottii as a study species. Two main objectives were established: Modelling the potential height of stands across different site qualities and modelling diameter increment using a potential modifier approach with a combination of competition indices that change in importance according to the edaphic conditions of the site. Potential height modelling used three steps in order to achieve this objective. The first was to compare site index models based on different model fitting techniques, namely nonlinear least squares, generalised nonlinear least squares and nonlinear mixed effects models. The nonlinear mixed effects model proved to be superior in terms of achieving the principles of regression assumptions and model fit for the data range observed. The second step was to fit potential height using nonlinear quantile regression on observed spacing trial height measurements. This proved to be a robust technique able to capture potentials according to the defined Chapman-Richards model structure. The final step was to use the predicted site index as a site classification variable in order to predict potential height. While some small deviation occurred, potential height seems to be well correlated to site index and validation on selected sites suggested that site index can be used to model potential height until a more sophisticated site classification model is used for future improvement of the model. Diameter increment modelling followed six major steps in order to apply the full parameterisation methodology of an age-independent diameter increment model dependent on tree diameter and competition. Diameter increment potentials were fit using site index as a predictor of the potential height curves. Multiple competition indices were tested on two sites to obtain a combination of two indices, which can capture overtopping and local crowding effects. Principle components analysis and variance inflation factors calculation were applied to test for collinearity between indices. Suitable combinations were tested resulting in a combination of the KKL and Local Basal Area competition indices. Changing importance of the two indices were observed on the two sites tested indicating a shift in the mode of competition according to a water gradient. These were combined in a deterministic potential modifier model, which mimicked competitive stages over age; however the validation showed a skewed distribution, which was not sensitive to stand density gradients. A stochastic model was constructed to model variance from observed residual plots using linear quantile regression to determine bounds for a truncated normal distribution which generates random deviates for a predicted increment. The stochastic element significantly improved the performance and sensitivity of the model, however the model was still not sensitive enough at very high and very low spacing densities. All in all two key models for an adaptation of an individual tree growth simulator to South African conditions were successfully demonstrated. The two main objectives were achieved; however some indicated improvements could be made, especially for the competition indices where the sensitivity of competition to changing resource limitation according to site and temporal scales needs to be further investigated. Furthermore, the full set of models for simulating individual tree growth still needs to be applied. Overall, as a methodological approach, the study outlined problems and future improvements, introduced new concepts and can serve as a guideline for future parameterisation of an individual tree growth model.
AFRIKAANSE OPSOMMING: In vergelyking met vakgroeimodelle, het individuele-boomgroeimodelle die potensiaal om die sensitiwiteit van plantasiegroeimodelle vir veranderende omstandighede soos aanpassings in boskultuur, onreëlmatige vakstrukture, ensovoorts, drasties te verbeter. Die doel van hierdie studie was om twee subkomponente van ‘n Europese individuele-boomgroeimodel uit te brei om sodoende individuele-boomgroei modelleringskonsepte in Suid-Afrika bekend te stel. Pinus elliottii is gebruik as studiespesie. Twee hoofdoelstellings is bepaal. Eerstens, die modellering van hoogtegroei potensiaal van opstande oor verskeie vlakke van groeiplek kwaliteit. Tweedens, die modellering van deursnee-aanwas deur gebruik te maak van ‘n potensiaal matigingsbenadering “potential modifier approach“ met ‘n kombinasie van kompetisie-indekse waarvan die belangrikheid verander volgens die edafiese toestande van die groeiplek. Die hoogtepotensiaalmodellering bestaan uit drie stappe. Tydens die eerste stap word groeiplek bonniteitsmodelle vergelyk op grond van verskillende modelpassingstegnieke, naamlik nie-lineêre minimum kwadrate, algemene nie-lineêre minimum kwadrate en nie-lineêre gemengde effek modelle. Laasgenoemde het die beste gevaar in terme van die beginsels van regressiemodelle asook die mate waarin die model die waargeneemde data pas. Tweedens is hoogtegroei potensiaal gemodelleer deur nie-lineêre kwantielregressie op waargeneemde hoogtes van spasiëringseksperimente toe te pas. Die metode is robuust en in staat om potensiale volgens die gedefinieerde Chapman Richards modelstruktuur vas te vang. Laastens is die voorspelde bonniteits indeks as ‘n groeiplek klassifasie veranderlike gebruik om sodoende die hoogtegroei potensiaal te voorspel. Alhoewel klein afwykings voorgekom het, blyk hoogtegroei potensiaal goed gekorreleer te wees met bonniteits indeks. Uit validasie op geselekteerde groieplekke blyk dit dat bonniteits indeks gebruik kan word om hoogtegroei potensiaal te modelleer totdat ‘n meer gesofistikeerde groeiplek klassifikasiemodel beskikbaar is wat die model verder sal kan vebeter. Die volledige parametriseringsmetodiek van ‘n ouderdoms-onafhanklike deursnee-aanwas model wat afhanklik is van boomdeursnee en kompetisie bestaan uit ses hoof prosesse. Nie-lineêre kwantielregressie is gebruik om deursnee-aanwaspotensiale te pas vir verskeie groeiplekke. Dié is gekombineer met ‘n bonniteits indeks om ‘n nuwe model te vorm waarmee hoogtegroeipotensiaal kurwes voorpel kon word. Daar is met veelvuldige kompetisie-indekse op twee groeiplekke geëksperimenteer om ‘n kombinasie van slegs twee indekse te vind wat die effekte van oorskaduwing en plaaslike verdringing kan vasvang, te vind. Hoof komponent analise “Principle components analysis” en variansie inflasie faktore berekening “variance inflation factors calculation” is gebruik om vir kollineariteit tussen die indekse te toets. Gepaste indekskombinasies is getoets. ‘n Kombinasie van die KKL en plaaslike basale oppervlakte “Local Basal Area” kompetisie-indekse het die beste resultate gelewer. Die twee indekse is as volg geselekteer. Veranderings in die belangrikheid van elk van die indekse is waargeneem op die twee toetspersele. Dit dui op ‘n verskuiwing in die modus van kompetisie afhangend van ‘n watergradiënt. Die twee indekse is gekombineer in ‘n deterministiese potensiaal matigings model wat die kompeterende stadiums oor ouderdom naboots. Validasie het egter ‘n skewe verdeling wat nie sensitief vir opstandsdigtheidsgradiënte is nie, gewys. ‘n Stogastiese model is ontwikkel om variansie in die residuele grafieke te modelleer. Lineêre kwantielregressie is gebruik om grense vir ‘n afgestompte normaalverdeling wat ewekansige afwykings vir ‘n voorspelde aanwas te bepaal. Die stogastiese element het die prestasie van die deterministiese model merkbaar verbeter. Selfs met die stogastiese element, is die model egter steeds nie sensitief genoeg vir baie hoë en baie lae opstandsdigthede nie. Ter opsomming is twee modelle vir ‘n aanpassing van ‘n individuele-boomgroeisimuleerder vir Suid- Afrikaanse toestande suksesvol gedemonstreer. Die twee hoofdoelstellings is bereik. Daar is egter steeds ‘n paar aangeduide verbeterings wat aangebring kan word. Die sensitiwiteit van die kompetisie-indekse op hulpbronbeperkings wat verander op grond van die ruimtelike en temporale skale moet veral verder bestudeer word. Verder moet die volle stel modelle wat benodig word om individuele-boomgroei te modelleer nog toegepas word. As ‘n metodologiese benadering, het die studie probleme uitgewys en toekomstige verbeterings aangedui, nuwe konsepte bekendgestel en kan dus dien as ‘n riglyn vir toekomstige parametrisering van individuele-boomgroeimodelle.

Este trabalho tem como propósito, caracterizar um sensor capaz de identificar o estado de umidade da madeira de Pinus da espécie Elliotti. O sensor projetado, foi implementado por duas placas metálicas de formato geométrico retangular formando um componente bipolar capacitivo. Para condicionar os sinais do sensor, foi implementado um circuito elétrico em ponte e integrado o sensor capacitivo nesse circuito elétrico que será alimentado por uma fonte de energia elétrica em corrente alternada (VCA) de alta frequência. O objetivo dessa integração, é obter nos ramos da ponte uma variação de sinal elétrico, em função da variação da reatância capacitiva entre as placas do sensor. A reatância capacitiva, é uma propriedade elétrica identificada na madeira quando essa atua como dielétrico entre as placas metálicas do sensor, e poderá sofrer variações em função da variação de umidade dos corpos de prova. Com a variação da reatância elétrica da madeira de pinus, foi possível registrar a variação da umidade dos corpos de prova tendo como parâmetro as variações dos sinais elétrico fornecidos pela ponte em função da reatância capacitiva. Para se obter os registros e realizar um método de comparação entre a umidade dos corpos de prova e sinal elétrico, os corpos de prova foram inicialmente saturados com água e durante um processo de secagem, foram coletados valores de leitura das grandezas elétrica envolvidas durante intervalos de tempos iguais até atingir o peso de massa seca. O diferencial desse trabalho em relação a outros do mesmo tema, é a sua capacidade de identificar em apenas uma ação, sem a utilização de processos destrutivos, pequenas áreas úmidas dentro de uma área de maior dimensão do material analisado. Os resultados obtidos, poderão ser visualizadas através de quadros, tabelas e gráficos.
This work proposes to characterize a sensor able to identify the Pinus wood moisture status of the Elliotti species. The designed sensor was implemented by two metal plates of rectangular geometric shape forming a bipolar capacitive component. To conditionate the sensor signals, a bridged electric circuit has been implemented and the capacitive sensor integrated into this electrical circuit to be fed by a high frequency alternating current power source (VCA). The purpose of this integration is to obtain in the bridge’s branches an electric signal variation, as a capacitive reactance variation function between the sensor plates. Capacitive reactance is an electrical property identified in the wood when it acts as a dielectric between the sensor metal plates, and may suffer variations depending on the sample humidity variation. With the Pinus wood electric reactance variation, it was possible to record the humidity variation of the samples having as a parameter the electric signals variations provided by the bridge as a capacitive reactance function. In order to obtain the records and perform a comparison method between the humidity of the samples tests and the electrical signal, the samples were initially saturated with water and during a drying process, and the values of the electrical quantities involved were collected during equal time periods, until reaching the dry mass weight. The differential of this work in relation to others of the same theme, is its ability to identify in only one action, without destructive processes usage, small humid spots within a larger area of the analyzed material. The obtained results can be visualized through tables, tables and graphs.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Historically, in Brazil, small farms were used as a source of livelihood or recreation areas, currently also as a way to supplement income or a way to ensure security. These small investors, for lack of knowledge often end up leaving to make economic analyzes and market behavior before engaging in forestry projects. The work aimed to study the behavior of prices of eucalyptus wood and gum rosin of Pinus elliottii and the economic viability of traditional manner and project alternative that aim to produce these two products. For this we used econometric univariate models to forecast the prices of the products studied, finding a maximum error of 4.65%. Conditional heteroscedasticity models were applied to predict the volatility of resin prices and eucalyptus wood prices for the process, which were 5.72% and 4.28% per month respectively. The bootstrap simulation method was used to determine the volatility of pine resin prices, and obtained a value of 8.76%. The theory of real options was used to determine the economic viability of projects, had their results compared with traditional methodologies. Furthermore, the volatility obtained by the conditional heterocedasticity model and the bootstrap alternative approaches were applied to this theory, no difference in volatility analysis obtained by the bootstrap method. It is indicated greater care in feasibility studies for forest projects across the long term that they demand and due to different results according to each methodology as demonstrated in this work.
Historicamente, no Brasil, pequenas propriedades rurais eram utilizadas como fonte de subsistência ou áreas de lazer, atualmente também como uma maneira de complementar a renda ou garantir uma forma de previdência. Esses pequenos investidores, por falta de conhecimento, muitas vezes acabam deixando de fazer análises econômicas e de comportamento de mercado antes de se envolverem em projetos florestais. O trabalho teve como objetivo estudar o comportamento dos preços da madeira de eucalipto e goma resina de Pinus elliottii e a viabilidade econômica de forma tradicional e alternativa de projetos que visam produzir esses dois produtos. Para isso foram utilizados modelos econométricos univariados para fazer a previsão dos preços dos produtos estudados, encontrando um erro máximo de 4,65%. Modelos de heterocedasticidade condicional foram aplicados para prever a volatilidade dos preços de resina e dos preços de madeira de eucalipto para processo, que foram de 5,72% e 4,28% ao mês respectivamente. O método de simulação bootstrap foi utilizado para verificar a volatilidade dos preços de resina pinus, sendo obtido um valor de 8,76%. A teoria das opções reais foi utilizada para verificar a viabilidade econômica de projetos, teve seus resultados comparados com metodologias tradicionais. Além disso, com a volatilidade obtida pelo modelo de heterocedasticidade condicional e pelo método bootstrap foram aplicadas abordagens alternativas dessa teoria, havendo diferença na análise com a volatilidade obtida pelo método bootstrap. Indicam-se maiores cuidados nos estudos de viabilidade para projetos florestais frente ao longo prazo que os mesmos demandam e devido a diferentes resultados de acordo com cada metodologia conforme foi demonstrado nesse trabalho.

In recent years research has shown that exposing seed to smoke or smoke solutions results in increased germination of some, but not all the species tested. Tests showed that exposing seeds of some commercial crops to smoke increased early plant growth. The stimulatory effects of smoke were shown to benefit the germination of species regardless of whether or not fire played a part of the species ecological cycle. In commercial forest nurseries any method of increasing the recovery rate of seed presents opportunities for realising savings of related production costs. Greater recovery rates of genetically improved seed present opportunities for capturing more related growth in field operations. Improving efficiencies of seed recovery at an early point in the production chain have multiplied effects further on down the chain. Two species of pine, namely Pinus taeda and Pinus elliottii that do not generally present high rates of germination were selected to test if applications of smoke solution could increase germination or emergence rates by more than 5%. As seed of both species are known to respond positively to existing seed pre-treatments the effects of smoke needed to be tested in combination, and apart from the pre-treatments. A secondary aim of the study was to examine the effect of smoke on early plant growth. Attempts to optimizes the concentration of the smoke solution were not undertaken as part of this study, as a rinsing treatment, included in the trials, is known to remove any inhibitory effects of a high concentration of the smoke solution. Tests to determine the variability of the seedlots was carried out for statistical purposes. The interaction between smoke application and pre-treatments were tested, firstly in Petri dishes under controlled environmental conditions, and then in nursery trays under standard commercial nursery conditions for both species. The inclusion of smoke in combination with the target moisture stratification (TMS and rinse pre treatment) had a significantly positive effect on P. taeda in a controlled environment. The same combination did not yield a positive results when tested under nursery conditions. Recommendations are made regarding future tests to see if the beneficial combination found in the controlled environment could be replicated under nursery conditions. Further motivation for conducting the tests exists in that the particular combination set gave significantly better early plant growth under nursery conditions. No other combinations tested yielded positive results.
Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.

 The method of classification of softwood timber poles within Australia is adopted directly from the United States of America, whereby a pole is classified by its groundline circumference which was determined from a given pole tip load and a fibre stress value (as determined from previous testing). Consequently, the derivation of the basis for classification is based on strength and stiffness values determined from the testing of American timber. This study was conducted to determine the strength and stiffness of Queensland plantation grown softwood. 

The strength and stiffness of timber is expressed by the Modulus of Rupture (MOR) and Modulus of Elasticity (MOE), respectively. 

The samples selected for testing were two lots of 40 specimens of the species Slash Pine (Pinus Elliotti). One sample consisted of poles 9.1m in length, the other 7.6m in length. The species and length of the specimens represent the product of timber poles most commonly utilised by industry. The size of the sample was determined so to be both economic and also to produce results which were a valid indication of the entire population. 

Specimens were tested by cantilever loading. Full size poles were placed horizontally into a rigid clamp. A load was then applied to the tip of the pole until failure occurred. The load at failure and corresponding deflection were measured, from which the MOR and MOE of each pole was determined.