Thesis (MEng)--University of South Australia, 1997

Eucalyptus pellita is a commercially important plantation hardwood species for the humid tropics of north Queensland. This species is favoured by both small-scale growers for use in mixed species woodlots targeting low-volume high-value sawn timber, and also by industrial forest companies growing monocultures for integrated pulp – sawn timber regimes. This study investigated whether mixed-species designs can increase the growth of this tropical eucalypt when compared to monocultures.A replacement series experiment with monocultures of Eucalyptus pellita (E) and Acacia peregrina (A) and mixtures in various proportions (75E:25A, 50E:50A, 25E:75A) was used to examine questions about growth and productivity. The trial was located on the Atherton Tablelands of north Queensland, Australia. High mortality in the establishment phase due to repeated damage by tropical cyclones altered the trial design. Effects of experimental designs on tree growth were estimated using a linear mixed effects model with restricted maximum likelihood analysis (REML). Volume growth of individual eucalypt trees were positively affected by the presence of acacia trees at age five years and this effect generally increased with time up to age 10 years. However, the stand volume and basal area increased with increasing proportions of E. pellita, due to its larger individual tree size. Conventional analysis did not offer convincing support for mixed-species designs. Preliminary individual-based modelling using a modified Hegyi competition index offered a solution and an equation that indicates acacias have positive ecological interactions (facilitation or competitive reduction), and definitely do not cause competition like E. pellita. These results suggest that significantly increased growth rates could be achieved with mixed-species designs over E. pellita monocultures. This statistical methodology could enable a better 4 understanding of species interactions in similarly altered experiments, or undesigned mixed-species plantations.The effects of trees on soils are highly variable and highly site and species specific. That trees can change soil chemistry over time is well established. The soil chemical properties under the eucalypt: acacia experiment were compared to several potential baseline data sources: the reference description of this soil type; those measured at 7 months after planting; and with those of soils under two adjacent vegetation types (forest and pasture) when the experiment was aged 9 years. At 9 years after planting soil total nitrogen increased with increasing proportion of acacias in the treatment. The mean total N under the acacia monoculture was significantly higher (P = 0.041) than that of either the eucalypt monoculture, or the surrounding pasture. The proportion of acacia in the treatment was positively linearly correlated with soil total N (r2 = 0.46; P = 0.018). Soils under the eucalypt monocultures were more similar to those under pasture for a range of soil chemical properties, compared with soils under treatments containing acacias. Results from this site show that the two species alter the soil chemistry in different ways. It is possible that the increased total N under the acacias could be facilitating the growth of the E. pellita, however without n-fixation analysis or tissue sampling it is not possible to confirm that the eucalypt is using the N. Similar cause and effect (or ‘supply and use’) questions also remain for soil pH and available phosphorus changes with increasing acacia in treatment. This study also demonstrates the difficulty in monitoring changes in soil properties over long cycles of forest plantations.The photosynthetic response to light was assessed in the stratified canopy of the mixed species field trial of the eucalypt: acacia experiment, and among commonly planted taxa of E. pellita in glasshouse pot trials. In the field trial photosynthetic capacity of fully5 expanded sun and shade leaves of both species was measured. E. pellita has a wide natural distribution with considerable variation in morphology and growth within the species, with several provenances commonly planted in north Queensland. Photosynthetic capacity and leaf nutrient content of three of these taxa (two from northern occurrences and one from southern occurrences of E. pellita) were measured on two occasions in glasshouse pot trials. A non rectangular hyperbolic function was used to describe the light response curves, and analysis of variance was used to determine differences in the biologically relevant curve parameters between treatments. In the field trial sun and shade leaves of E. pellita produced similar light saturated photosynthetic rates, and experienced little competition for light from the acacia crowns. In contrast there was significant variation in the photosynthetic response between acacia sun and shade leaves. In the glasshouse trials, differences in leaf and petiole morphology were observed, which were coupled with differences in leaf nutrient content and highly significant variation in light saturated photosynthetic rate between the three taxa. This study characterised the light response of E. pellita and suggests that differences in physiological responses to resource availability should be expected among taxa within this species, which may be important for forest productivity models which endeavour to predict tree growth and resource use.An empirical model of growth of E. pellita from a designed monocultures vs. mixedspecies experiment has been used to explore system behaviour rather than predict production of this species from specific forests. This approach has allowed examination of the effect of plantation design on competition, soil nutrient pool change with time and physiological responses to light; leading to a greater understanding of why mixtures can lead to greater productivity than monocultures.

Eucalyptus pellita is a commercially important plantation hardwood species for the humid tropics of north Queensland. This species is favoured by both small-scale growers for use in mixed species woodlots targeting low-volume high-value sawn timber, and also by industrial forest companies growing monocultures for integrated pulp – sawn timber regimes. This study investigated whether mixed-species designs can increase the growth of this tropical eucalypt when compared to monocultures.A replacement series experiment with monocultures of Eucalyptus pellita (E) and Acacia peregrina (A) and mixtures in various proportions (75E:25A, 50E:50A, 25E:75A) was used to examine questions about growth and productivity. The trial was located on the Atherton Tablelands of north Queensland, Australia. High mortality in the establishment phase due to repeated damage by tropical cyclones altered the trial design. Effects of experimental designs on tree growth were estimated using a linear mixed effects model with restricted maximum likelihood analysis (REML). Volume growth of individual eucalypt trees were positively affected by the presence of acacia trees at age five years and this effect generally increased with time up to age 10 years. However, the stand volume and basal area increased with increasing proportions of E. pellita, due to its larger individual tree size. Conventional analysis did not offer convincing support for mixed-species designs. Preliminary individual-based modelling using a modified Hegyi competition index offered a solution and an equation that indicates acacias have positive ecological interactions (facilitation or competitive reduction), and definitely do not cause competition like E. pellita. These results suggest that significantly increased growth rates could be achieved with mixed-species designs over E. pellita monocultures. This statistical methodology could enable a better 4 understanding of species interactions in similarly altered experiments, or undesigned mixed-species plantations.The effects of trees on soils are highly variable and highly site and species specific. That trees can change soil chemistry over time is well established. The soil chemical properties under the eucalypt: acacia experiment were compared to several potential baseline data sources: the reference description of this soil type; those measured at 7 months after planting; and with those of soils under two adjacent vegetation types (forest and pasture) when the experiment was aged 9 years. At 9 years after planting soil total nitrogen increased with increasing proportion of acacias in the treatment. The mean total N under the acacia monoculture was significantly higher (P = 0.041) than that of either the eucalypt monoculture, or the surrounding pasture. The proportion of acacia in the treatment was positively linearly correlated with soil total N (r2 = 0.46; P = 0.018). Soils under the eucalypt monocultures were more similar to those under pasture for a range of soil chemical properties, compared with soils under treatments containing acacias. Results from this site show that the two species alter the soil chemistry in different ways. It is possible that the increased total N under the acacias could be facilitating the growth of the E. pellita, however without n-fixation analysis or tissue sampling it is not possible to confirm that the eucalypt is using the N. Similar cause and effect (or ‘supply and use’) questions also remain for soil pH and available phosphorus changes with increasing acacia in treatment. This study also demonstrates the difficulty in monitoring changes in soil properties over long cycles of forest plantations.The photosynthetic response to light was assessed in the stratified canopy of the mixed species field trial of the eucalypt: acacia experiment, and among commonly planted taxa of E. pellita in glasshouse pot trials. In the field trial photosynthetic capacity of fully5 expanded sun and shade leaves of both species was measured. E. pellita has a wide natural distribution with considerable variation in morphology and growth within the species, with several provenances commonly planted in north Queensland. Photosynthetic capacity and leaf nutrient content of three of these taxa (two from northern occurrences and one from southern occurrences of E. pellita) were measured on two occasions in glasshouse pot trials. A non rectangular hyperbolic function was used to describe the light response curves, and analysis of variance was used to determine differences in the biologically relevant curve parameters between treatments. In the field trial sun and shade leaves of E. pellita produced similar light saturated photosynthetic rates, and experienced little competition for light from the acacia crowns. In contrast there was significant variation in the photosynthetic response between acacia sun and shade leaves. In the glasshouse trials, differences in leaf and petiole morphology were observed, which were coupled with differences in leaf nutrient content and highly significant variation in light saturated photosynthetic rate between the three taxa. This study characterised the light response of E. pellita and suggests that differences in physiological responses to resource availability should be expected among taxa within this species, which may be important for forest productivity models which endeavour to predict tree growth and resource use.An empirical model of growth of E. pellita from a designed monocultures vs. mixedspecies experiment has been used to explore system behaviour rather than predict production of this species from specific forests. This approach has allowed examination of the effect of plantation design on competition, soil nutrient pool change with time and physiological responses to light; leading to a greater understanding of why mixtures can lead to greater productivity than monocultures.

Thesis (doctoral)--Katholike Universiteit Nijmegen, 1973. / Includes bibliographical references.

Resumo : O uso de florestas de Eucalyptus tem se tornado cada vez mais expressivo no Brasil, sobretudo por conta da excelente produção em termos volumétricos por elas alcançada e pelas boas características da madeira obtida. Várias empresas do setor florestal estão em busca do aumento da produção de madeira por unidade de área, tentando identificar, nos regimes de manejo, a técnica que agrega mais fortemente qualidade ao produto final por eles gerado. Neste contexto, o presente trabalho foi desenvolvido buscando a identificação dos melhores espaçamentos de plantio para florestas clonais de um híbrido interespecífico de Eucalyptus grandis e Eucalyptus urophylla, de forma a maximizar a produção de biomassa do fuste por hectare, e como objetivos complementares analisar a influência do espaçamento de plantio no incremento anual em diâmetro, altura, área basal ao longo da idade, volume por árvore e por hectare, além do percentual de casca das árvores e densidade básica da madeira no último ano. Os dados foram disponibilizados pela empresa Duraflora S.A. e são provenientes de um teste clonal exploratório que visa o aumento da produtividade e melhoria da qualidade da matéria prima através do estudo de espaçamentos. O delineamento estatístico utilizado foi o sistemático com fator quantitativo contínuo, com 16 tratamentos e 40 repetições, considerando que a variação entre os tratamentos foi o espaçamento entre as árvores e a entrelinha possuía um espaçamento constante de três metros. Com este arranjo, o experimento possuiu espaçamentos variando de 1,50m2 de área vital por árvore (6.667 árvores por hectare) até 15,75m2 de área vital árvore (635 árvores por hectare). A altura e o diâmetro à altura do peito -DAP foram medidos aos 36, 48, 60 e 72 meses de idade, e somente no ultimo... (Resumo completo, clicar acesso eletrõnico abaixo) / Abstract: The use of forests of Eucalyptus has become each time more expressive in Brazil, over all on account of the excellent production in volumetric terms for them reached and the good characteristics of the gotten wood. Some companies of the forest sector are in search of the increase of the wooden production for unit of area, trying to identify, in regimes of handling, the technique that strong adds more quality to the end item for them generated. In this context, the present work was developed to search the bests plantations spacing for clonal forests of a interspecific hybrid of Eucalyptus grandis and Eucalyptus urophylla, to maximize the production of the stem biomass per hectare, and as a complementary objective to analyze the influence of the plantation spacing in the annual increment in diameter, height, stem volume and volume per hectare, basal area throughout the age, beyond the percentage of bark of the trees and basic density of the wood in the last year. The data came from the Duraflora Company and are proceeding from a clonal test exploration that aims at the increase of the productivity and improvement of the quality of the substance cousin through the study of plantations spacing. The used statistical delineation was the systematic with continuous quantitative factor, 16 treatments and 40 repetitions, considering that the variation between the treatments was only the spacing between the trees and the space between lines was a constant of 3 meters. With this arrangement, the vital area for tree was about 1,50m2 (6,667 trees per hectare) until 15,75m2 (635 trees per hectare). The trees height and the diameter breast height - DBH had been measured to the age of 36, 48, 60 and 72 months, and only in the last year three trees of each treatment had been sampled to... (Complete abstract click electronic access below) / Orientador: Adriano Wagner Ballarin / Coorientador: Luiz Alberto Blanco Jorge / Banca: José Nivaldo Garcia / Banca: Hernando Alfonso Lara Palma / Mestre

Made available in DSpace on 2014-06-11T19:30:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-08-25Bitstream added on 2014-06-13T19:19:02Z : No. of bitstreams: 1 santos_md_me_botfca.pdf: 2278704 bytes, checksum: 8b089e60925e4ff1a31aa9f4f65e2eb1 (MD5) / O uso de florestas de Eucalyptus tem se tornado cada vez mais expressivo no Brasil, sobretudo por conta da excelente produção em termos volumétricos por elas alcançada e pelas boas características da madeira obtida. Várias empresas do setor florestal estão em busca do aumento da produção de madeira por unidade de área, tentando identificar, nos regimes de manejo, a técnica que agrega mais fortemente qualidade ao produto final por eles gerado. Neste contexto, o presente trabalho foi desenvolvido buscando a identificação dos melhores espaçamentos de plantio para florestas clonais de um híbrido interespecífico de Eucalyptus grandis e Eucalyptus urophylla, de forma a maximizar a produção de biomassa do fuste por hectare, e como objetivos complementares analisar a influência do espaçamento de plantio no incremento anual em diâmetro, altura, área basal ao longo da idade, volume por árvore e por hectare, além do percentual de casca das árvores e densidade básica da madeira no último ano. Os dados foram disponibilizados pela empresa Duraflora S.A. e são provenientes de um teste clonal exploratório que visa o aumento da produtividade e melhoria da qualidade da matéria prima através do estudo de espaçamentos. O delineamento estatístico utilizado foi o sistemático com fator quantitativo contínuo, com 16 tratamentos e 40 repetições, considerando que a variação entre os tratamentos foi o espaçamento entre as árvores e a entrelinha possuía um espaçamento constante de três metros. Com este arranjo, o experimento possuiu espaçamentos variando de 1,50m2 de área vital por árvore (6.667 árvores por hectare) até 15,75m2 de área vital árvore (635 árvores por hectare). A altura e o diâmetro à altura do peito -DAP foram medidos aos 36, 48, 60 e 72 meses de idade, e somente no ultimo... / The use of forests of Eucalyptus has become each time more expressive in Brazil, over all on account of the excellent production in volumetric terms for them reached and the good characteristics of the gotten wood. Some companies of the forest sector are in search of the increase of the wooden production for unit of area, trying to identify, in regimes of handling, the technique that strong adds more quality to the end item for them generated. In this context, the present work was developed to search the bests plantations spacing for clonal forests of a interspecific hybrid of Eucalyptus grandis and Eucalyptus urophylla, to maximize the production of the stem biomass per hectare, and as a complementary objective to analyze the influence of the plantation spacing in the annual increment in diameter, height, stem volume and volume per hectare, basal area throughout the age, beyond the percentage of bark of the trees and basic density of the wood in the last year. The data came from the Duraflora Company and are proceeding from a clonal test exploration that aims at the increase of the productivity and improvement of the quality of the substance cousin through the study of plantations spacing. The used statistical delineation was the systematic with continuous quantitative factor, 16 treatments and 40 repetitions, considering that the variation between the treatments was only the spacing between the trees and the space between lines was a constant of 3 meters. With this arrangement, the vital area for tree was about 1,50m2 (6,667 trees per hectare) until 15,75m2 (635 trees per hectare). The trees height and the diameter breast height - DBH had been measured to the age of 36, 48, 60 and 72 months, and only in the last year three trees of each treatment had been sampled to... (Complete abstract click electronic access below)

The ability of eucalypt trees to grow in different soil aspects, under variable climatic and environmental conditions and to grow fast consistently producing straight stems has made them preferred plantation trees in many parts of the world. The world‘s increased demand for pulp wood has been the major contributor to the aggressive extensive development of eucalyptus plantations around the world. The productivity of these trees is however hindered in both native and introduced plantations by pests and pathogens. Chapter 1 of this thesis is a literature review on Teratosphaeria suttonii as the causative agent of Teratosphaeria Leaf Disease on Eucalyptus. The chapter highlights the taxonomic placement of T. suttonii in the genus Teratosphaeria and the name changes of the species as a consequence of molecular taxonomy. The effects of the pathogen on Eucalyptus plantations in different parts of the world as well as the incidence and range of Eucalyptus species that host the pathogen are presented. In addition the review summarizes much of the information published on the distribution, hosts range and evolutionary relationships of T. suttonii with closely related species in the genus Teratosphaeria. In conclusion, it highlights the lack of understanding of the degree of diversity of the pathogen from different parts of the world. In order to characterize and establish the phylogenetic relationships between T. suttonii isolates from different countries, chapter 2 of this thesis considered microscopic examination and DNA sequence comparisons of isolates from its native and introduced localities. The isolates were classified into a single genetically and morphologically diverse group within which representatives of different countries were intermixed in smaller groups. A high level of genetic variation was evident among Australia isolates but despite the diversity there was no overwhelming evidence for sibling species. In Chapter 3 of this thesis eleven microsatellite markers were developed from three T. suttonii isolates obtained from 2 geographic areas. The markers were used in Chapters 4 and 5 to investigate the genetic diversity of T. suttonii in both its native and introduced environments and to establish factors underlying such diversity. The application of the markers in Chapters 4 and 5 provide the first consideration of the diversity of T. suttonii in both its native and introduced localities respectively. Both native and introduced pathogen populations exhibit substantially high genotypic diversities. It is evident from these studies that Australia is the point of origin of T. suttonii and that anthropogenic activities have resulted in repeated introductions of the pathogen from Australia into many countries. Teratosphaeria suttonii is of great significance to the eucalyptus plantation industry across the world. Movement of diseased germplasm and introduction of new genotypes favors pathogen adaptability. In order to reduce the distribution of the pathogen into new areas or any other places where it might have negative effects, strict quarantine procedures should be followed. / Thesis (PhD)--University of Pretoria, 2013. / gm2013 / Microbiology and Plant Pathology / Unrestricted

Conversion of tropical forests into oil palm plantations reduces the habitats of many species, including primates, and frequently leads to human–wildlife conflicts. Contrary to the widespread belief that macaques foraging in the forest–oil palm matrix are detrimental crop pests, we show that the impact of macaques on oil palm yield is minor. More importantly, our data suggest that wild macaques have the potential to act as biological pest control by feeding on plantation rats, the major pest for oil palm crops, with each macaque group estimated to reduce rat populations by about 3,000 individuals per year (mitigating annual losses of 112 USD per hectare). If used for rodent control in place of the conventional method of poison, macaques could provide an important ecosystem service and enhance palm oil sustainability.

Procuring hardwood pulpwood during the winter months for a pulp mill in the Southeast can be difficult. Saturated soils and low soil strength make logging difficult or impossible on many sites, forcing companies to store large volumes of hardwood pulpwood in woodyards for retrieval during wet weather. Hardwood fiber readily available in large volumes on ground that is operable during wet periods at a location near the pulp mill could provide a valuable alternative wood source. Thus, the objectives of this study are to 1) develop a decision model for a manager to use to determine the feasibility of strategically located, intensively-managed, short-rotation hardwood fiber farms as pulp mill furnish, 2) use the model to estimate wood costs for a hypothetical eastern cottonwood plantation, and 3) use the model to determine if a fiber farm grown on drier, upland sites ("green" inventory) could be used to reduce woodyard winter inventories and economically supply a nearby pulp mill during a wood shortage, thus reducing high cost, emergency "spot market" wood purchases. The decision model is incorporated in a spreadsheet and includes all the costs typical for a fiber farm. The model is tested using current establishment and management costs from the literature and yields from an experimental fiber farm in the southeast. Under current yields, delivered costs from the fiber farm averages $71/ton. With potential increased yields that could occur with genetic improvements and operational optimizations, delivered cost for fiber farm wood could be reduced to $56/ton. In comparison, the highest cost wood purchased by the three cooperating pulp mills during the study period was $50.23/ton. The net present values of a fiber farm as "green" inventory were determined using actual wood cost and inventory levels from three cooperating southeastern pulp mills. For the "green" inventory analysis, all three pulp mills would have lowered their overall wood cost using a fiber farm (with higher yield) as "green" inventory, primarily by reducing the amount of wood required as dry inventory on woodyards. Savings accrued during "dry" years offset the higher cost of hardwood plantation deliveries. A sensitivity analysis was performed to determine the optimal size fiber farm for one of the cooperating pulp mills and indicated that 800 acres would be the most beneficial. / Ph. D.

Short-rotation woody crops are becoming important supplies of hardwood fiber, but little is known about the early nutritional needs of these systems, especially on different site types. The study objectives were, on two young (ages 3-6) sweetgum plantations with contrasting soil types, to 1) determine the plant growth and foliar nutrition response to repeated nitrogen (N) fertilizer applications, 2) determine soil N supply, plant N demand, foliar N resorption, and soil and fertilizer uptake efficiencies, and 3) test a simple N supply model. In order to expand the findings to the range of sweetgum site types, the study objectives were also to 4) evaluate rapid methods for determining N mineralization potential, 5) characterize the soils of 14 sweetgum site types in the Atlantic coastal plain, and 6) review current N fertilizer prescriptions in forestry and recommend strategies for improvement. Two young sweetgum (Liquidambar styraciflua L.) plantations on a converted agricultural field and a pine cutover site in South Carolina were fertilized biannually with three rates of N fertilizer (0, 56, 112 kg N per ha). Fertilization doubled foliar biomass and leaf area on the cutover pine site in the years fertilizer was applied, and stem biomass increased 60%. Critical values, the N concentration required for 90% of optimum growth, is approximately 1.75%. Foliar N uptake increased at both sites when fertilizer was applied. Modeled annual soil N supply was within 20% of that measured on the two plantations even though monthly N supply was not accurately estimated. Potential N mineralization was accurately estimated with a 3-day incubation of rewetted soils that were previously dried, but not by hot salt extraction or anaerobic incubation. Across a spectrum of 14 sweetgum sites, the agricultural fields had lower mineralizable nitrogen (126 kg per ha) than the cutover sites (363 kg per ha). Current N fertilizer prescriptions are not sufficient for repeated fertilizer applications to fast-growing hardwood plantations, but simple models of soil N supply and an N-balance approach may improve prescriptions. / Ph. D.