This thesis examines the effects of species, rainfall and soil type on tree biomass regressions, as well as the effects of stand dominance and structure on stand biomass regressions in north-east Australian woodlands. This was achieved by examining tree characteristics and biomass relationships for a series of woodland monitoring sites throughout the study area. This study utilised a modified data set from this permanent monitoring site network to provide structural attributes for trees and communities of varying composition in the grazed woodlands. These data were supplemented with environmental data and tree harvest data sets. Initially, the research reported in this thesis developed allometric and stand biomass regressions for Callitris glaucophylla communities. This research also demonstrated that changes in tree-form were not reflected in changes in the environment, nor did such changes reflect changes in tree biomass regressions for three eucalypt species. As a result, a common regression provides a robust estimate of total aboveground biomass of eucalypt trees in the study area. Thus expensive destructive harvesting can generally be avoided for minor eucalypt species. Finally, this study demonstrated a successful methodology that described the stand structure of all the grazed woodland sites based on tree heights. This methodology was developed to allow the expansion of a single stand regression to estimate stand biomass across the entire north-east Australian woodlands. The findings demonstrated in this study, combined with the long-term data from the permanent monitoring network sites, should enhance the estimation of carbon flux within eucalypt communities of north-east Australia’s grazed woodlands.

Two eucalypt clines were examined using morphological, ecophysiological and molecular analyses. The species complexes examined were an ironbark complex (Eucalyptus melanophloia x E. whitei) and a box complex (E. brownii x E. populnea). Both of these complexes demonstrate continuous morphological variation across their clines. The origin of these morphological clines has previously been interpreted as the product of secondary contact between allopatric species. In this study, an analysis of morphological variation across the clines did not identify an increase in trait variance in the intermediate populations, which suggests that previous theories concerning the origin of these clines may not be valid. Genetic structuring in nuclear and chloroplast DNA was examined across the clines to investigate whether the morphological clines were the product of secondary contact between two independent evolutionary lineages, or whether the clines represent a single evolutionary lineage that has undergone primary differentiation. The microsatellite analyses indicated that there was little genetic structuring across either cline, and that there were only low levels of population differentiation. The lack of hierarchical structuring in the distribution of nuclear genetic variation suggests that these clines are unlikely to be the product of recent gene flow between two formerly allopatric species/populations. A nested clade analysis of the JLA+ region of the cpDNA provides additional evidence to reject the null hypothesis that the morphospecies classifications represent distinct evolutionary lineages. Instead the analyses indicate that each cline represents a single cohesion species and a single evolutionary lineage. The phylogeographic distribution of cpDNA haplotypes is likely to have resulted from restricted seed mediated gene flow with isolation by distance. A more cogent explanation for the clines, based on the genetic data, is that they have arisen through the process of continuous morphological diversification that has been promoted by a directional selection gradient. Drought experiments were conducted in the glasshouse to investigate whether differences in physiological performance under water stress helps to explain the maintenance of the ironbark cline. Under increasing water stress, the morphotypes showed differences in their ability to maintain water status and photosynthetic rates, yet there was no obvious pattern to these differences across the cline. Physiological differences are therefore inadequate to explain the maintenance of the ironbark cline and highlight the compensatory role that morphological variation may play in alleviating water stress. The value of adopting the cohesion species concept and a hypothesis-testing framework to assess species status is demonstrated in this study. This framework provided a statistical approach to distinguish independent evolutionary lineages from interspecific populations and provides evidence to refute the current species status of the species complexes studied. Eucalypt classification is predominantly based on morphology, which results in taxonomic classification that may not reflect genealogical relationships. This is due to the disparity between morphological and phylogenetic relationships. I therefore suggest that current presumptions regarding the prevalence and importance of hybridisation within the genus may reflect taxonomic classification. An accurate assessment of the prevalence and importance of hybridisation requires species classification to be based on genealogical relationships.

Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / This research project was carried out using the ornamental species E. erythronema, E. stricklandii, their natural interspecific hybrid E. 'Urrbrae Gem', and artificial hybrids of these two species, with the aim of identifying a clonal propagation method for hybrid omamental eucalypts using the tissue culture techniques of micropropagation, organogenesis and somatic embryogenesis. Seeds of E. erythronema, E. stricklandii, and E. 'Urrbrae Gem' were decontaminated and germinated in culture for experiments on callus growth and response to plant growth regulators. Murashige and Skoog (1962) medium supplemented with 1 uM BAP, 10 uM NAA, 20 g⁻¹ sucrose, gelled with 7 g⁻¹ Phytagel® proved the most suitable callus growth medium when compared to those of Gamborg (1968), Lloyd and McCown (woody plant medium) (1980), Almehdi and Parfitt (1996) and de Fossard(1976) (Eucalyptus). A range and combination of plant growth regulators was used to investigate organogenesis, somatic embryogenesis and axillary shoot proliferation. A broad based experiment was first conducted to assess the response of the hybrid and its parental species to wide concentrations of commonly used auxins and cytokinins known to induce organogenesis and somatic embryogenesis. Callus growth was consistent across all genotypes and tissue types with soft and spongy callus growth in the presence of 2,4-D and hard and friable callus in the presence of NAA, while callus growth was greater with auxin or auxin/cytokinin (BAP or kinetin) combinations compared to cytokinin alone. Healthy root development was observed from treatments with NAA, while roots that developed from treatments with 2,4-D turned brown within 12 weeks. Bud development was observed with BAP alone or in combination with NAA with large bud clusters observed on E. erythronema and E. 'Urrbrae Gem' explants. Shoots, were observed in treatments with NAA alone, or in combination with BAP or kinetin, but not in treatments with 2,4-D. No somatic embryos were observed with any treatment or taxon. Light microscopy of explants treated with 2,4-D alone showed calli consisting only of large parenchyma cells, while 2,4¬D in combination with a cytokinin produced smaller parenchyma cells, with areas of vascular tissue and spherical growths. BAP, kinetin and NAA alone or in combination produced an increase in vascular tissue. Shoot and root initiation appeared to occur within the callus with connection to the vascular tissue. Shoot organogenesis from E. erythronema, E. stricklandii and E. 'Urrbrae Gem' seedlings and E. erythronema x E. stricklandii hybrid 2.5 was further investigated using apex and leaf explants with 1 uM and lower levels of BAP. Apex and leaf explants of E. erythronema and E. 'Urrbrae Gem' developed clusters of buds from the apex base and leaf petiole while apex and leaf explants of E. stricklandii and hybrid 2.5 produced individual buds. Bud and shoot development was greater on apex than leaf explants with 0.5 and 1 uM BAP producing the greatest shoot numbers. Light microscopy showed that meristem development had occurred within the callus and bud structures, but there were few shoot primordia considering the amount of meristem development (meristemoids). Somatic embryogenesis was further investigated in juvenile ad callus tissue using NAA, NAA/2,4-D combinations, and heat and smoked water treatments. Somatic embryogenesis was not observed macroscopically with 2,4-D and NAA treatments. Globular somatic embryo structures were observed on apex explants of 'Urrbrae Gem' seedlings at 2 wk on MS medium supplemented with 16.11 uM NAA but there was no development beyond the globular stage. Areas of defined callus development, which did not contain typical embryogenic cells, were observed on all treatments and genotypes. Root development was observed from all auxin treatments but was less on explants treated with 5.37 uM NAA/4.5 uM 2,4-D compared to NAA alone while roots and shoots developed simultaneously on apex explants after culture for 1 wk on MS medium supplemented with 80.55 uM NAA. Heat and smoked water were detrimental to E. 'Urrbrae Gem' callus and no somatic embryogenesis was observed. Explants from field trees of E. erythronema, E. stricklandii, E. 'Urrbrae Gem', E. erythronema x stricklandii hybrids 20E, 20P, 20R, 20T, 20V, 21A, 21G, 21U and potted plants of E. erythronema x E. stricklandii hybrids 35.2 and 2.5 growing under glasshouse conditions, were harvested and initiated into culture. Of the selected plants only explants from glasshouse grown material could be initiated into culture and multiplied. E. erythronema x stricklandii hybrids 35.2 and 2.5 . were multiplied by axillary shoot proliferation over 3 yr on Quoirin and Lepoivre medium (1977) with 2.2 uM BAP, 0.5 uM NAA and 0.5 uM GA3, 20 g⁻¹ sucrose, gelled with 7 g⁻¹ Phytagel®. However root growth proved difficult as shoots developed short thick roots that failed to elongate and the plants could not be hardened off. By using zeatin in the multiplication medium and activated charcoal after the IBA pulse elongated roots suitable for hardening off were developed. By comparison seedlings of E. 'Urrbrae Gem' were successfully germinated in culture and multiplied by axillary shoot proliferation using WPM, 2.2 uM BAP, 0.5 uMNAA and 0.5 uM GA3, 20 g⁻¹ sucrose, gelled with 7 g⁻¹ Phytagel®. They were rooted on 1/2WPM, 20 uM IBA, 10 g⁻¹ sucrose gelled with 7 g⁻¹ Phytagel® for 7 d, followed by subculture to PGR free medium. Following root initiation and growth plants were hardened off to the external environment. In conclusion genetic differences were observed between genotypes, in regards to initiation into culture, and response to nutrient medium, and plant growth regulators, with differences observed in explant deterioration, medium exudates, callus growth and appearance, somatic embryogenesis, bud, shoot and root organogenesis, axillary shoot development, and rooting of shoots. For organogenesis, juvenile explants were more responsive in culture than mature explants and potted plants more responsive than field plants for micropropagation. Shoot and root organogenesis was achieved from juvenile explants while shoot explants of E. erythronema x E, stricklandii hybrids were successfully micropropagated by axillary shoot proliferation. Somatic embryogenesis was observed with E. 'Urrbrae Gem' seedlings but was blocked at the globular stage. This research has provided a greater understanding of the clonal propagation requirements via tissue culture techniques for E. erythronema, E. stricklandii and their hybrids. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1177221 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture and Wine, 2005

Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / This research project was carried out using the ornamental species E. erythronema, E. stricklandii, their natural interspecific hybrid E. 'Urrbrae Gem', and artificial hybrids of these two species, with the aim of identifying a clonal propagation method for hybrid omamental eucalypts using the tissue culture techniques of micropropagation, organogenesis and somatic embryogenesis. Seeds of E. erythronema, E. stricklandii, and E. 'Urrbrae Gem' were decontaminated and germinated in culture for experiments on callus growth and response to plant growth regulators. Murashige and Skoog (1962) medium supplemented with 1 uM BAP, 10 uM NAA, 20 g⁻¹ sucrose, gelled with 7 g⁻¹ Phytagel® proved the most suitable callus growth medium when compared to those of Gamborg (1968), Lloyd and McCown (woody plant medium) (1980), Almehdi and Parfitt (1996) and de Fossard(1976) (Eucalyptus). A range and combination of plant growth regulators was used to investigate organogenesis, somatic embryogenesis and axillary shoot proliferation. A broad based experiment was first conducted to assess the response of the hybrid and its parental species to wide concentrations of commonly used auxins and cytokinins known to induce organogenesis and somatic embryogenesis. Callus growth was consistent across all genotypes and tissue types with soft and spongy callus growth in the presence of 2,4-D and hard and friable callus in the presence of NAA, while callus growth was greater with auxin or auxin/cytokinin (BAP or kinetin) combinations compared to cytokinin alone. Healthy root development was observed from treatments with NAA, while roots that developed from treatments with 2,4-D turned brown within 12 weeks. Bud development was observed with BAP alone or in combination with NAA with large bud clusters observed on E. erythronema and E. 'Urrbrae Gem' explants. Shoots, were observed in treatments with NAA alone, or in combination with BAP or kinetin, but not in treatments with 2,4-D. No somatic embryos were observed with any treatment or taxon. Light microscopy of explants treated with 2,4-D alone showed calli consisting only of large parenchyma cells, while 2,4¬D in combination with a cytokinin produced smaller parenchyma cells, with areas of vascular tissue and spherical growths. BAP, kinetin and NAA alone or in combination produced an increase in vascular tissue. Shoot and root initiation appeared to occur within the callus with connection to the vascular tissue. Shoot organogenesis from E. erythronema, E. stricklandii and E. 'Urrbrae Gem' seedlings and E. erythronema x E. stricklandii hybrid 2.5 was further investigated using apex and leaf explants with 1 uM and lower levels of BAP. Apex and leaf explants of E. erythronema and E. 'Urrbrae Gem' developed clusters of buds from the apex base and leaf petiole while apex and leaf explants of E. stricklandii and hybrid 2.5 produced individual buds. Bud and shoot development was greater on apex than leaf explants with 0.5 and 1 uM BAP producing the greatest shoot numbers. Light microscopy showed that meristem development had occurred within the callus and bud structures, but there were few shoot primordia considering the amount of meristem development (meristemoids). Somatic embryogenesis was further investigated in juvenile ad callus tissue using NAA, NAA/2,4-D combinations, and heat and smoked water treatments. Somatic embryogenesis was not observed macroscopically with 2,4-D and NAA treatments. Globular somatic embryo structures were observed on apex explants of 'Urrbrae Gem' seedlings at 2 wk on MS medium supplemented with 16.11 uM NAA but there was no development beyond the globular stage. Areas of defined callus development, which did not contain typical embryogenic cells, were observed on all treatments and genotypes. Root development was observed from all auxin treatments but was less on explants treated with 5.37 uM NAA/4.5 uM 2,4-D compared to NAA alone while roots and shoots developed simultaneously on apex explants after culture for 1 wk on MS medium supplemented with 80.55 uM NAA. Heat and smoked water were detrimental to E. 'Urrbrae Gem' callus and no somatic embryogenesis was observed. Explants from field trees of E. erythronema, E. stricklandii, E. 'Urrbrae Gem', E. erythronema x stricklandii hybrids 20E, 20P, 20R, 20T, 20V, 21A, 21G, 21U and potted plants of E. erythronema x E. stricklandii hybrids 35.2 and 2.5 growing under glasshouse conditions, were harvested and initiated into culture. Of the selected plants only explants from glasshouse grown material could be initiated into culture and multiplied. E. erythronema x stricklandii hybrids 35.2 and 2.5 . were multiplied by axillary shoot proliferation over 3 yr on Quoirin and Lepoivre medium (1977) with 2.2 uM BAP, 0.5 uM NAA and 0.5 uM GA3, 20 g⁻¹ sucrose, gelled with 7 g⁻¹ Phytagel®. However root growth proved difficult as shoots developed short thick roots that failed to elongate and the plants could not be hardened off. By using zeatin in the multiplication medium and activated charcoal after the IBA pulse elongated roots suitable for hardening off were developed. By comparison seedlings of E. 'Urrbrae Gem' were successfully germinated in culture and multiplied by axillary shoot proliferation using WPM, 2.2 uM BAP, 0.5 uMNAA and 0.5 uM GA3, 20 g⁻¹ sucrose, gelled with 7 g⁻¹ Phytagel®. They were rooted on 1/2WPM, 20 uM IBA, 10 g⁻¹ sucrose gelled with 7 g⁻¹ Phytagel® for 7 d, followed by subculture to PGR free medium. Following root initiation and growth plants were hardened off to the external environment. In conclusion genetic differences were observed between genotypes, in regards to initiation into culture, and response to nutrient medium, and plant growth regulators, with differences observed in explant deterioration, medium exudates, callus growth and appearance, somatic embryogenesis, bud, shoot and root organogenesis, axillary shoot development, and rooting of shoots. For organogenesis, juvenile explants were more responsive in culture than mature explants and potted plants more responsive than field plants for micropropagation. Shoot and root organogenesis was achieved from juvenile explants while shoot explants of E. erythronema x E, stricklandii hybrids were successfully micropropagated by axillary shoot proliferation. Somatic embryogenesis was observed with E. 'Urrbrae Gem' seedlings but was blocked at the globular stage. This research has provided a greater understanding of the clonal propagation requirements via tissue culture techniques for E. erythronema, E. stricklandii and their hybrids. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1177221 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture and Wine, 2005

Plantation eucalypts are a recent and rapidly growing industry in Australia, and will eventually replace the logging of old-growth forests. Over 40% of these plantations have been established in south-western Australia, where more than 160 000 ha of Eucalyptus globulus plantations now occur. In the early 1900’s, this species was widely planted as an exotic in South Africa, but succumbed to severe pest (Gonipterus sp.) and disease (Mycosphaerella sp.) problems. Similarly, in south-western Australia E. globulus is an exotic species, but with the additional threat that it is planted adjacent to indigenous eucalypts, which increases the possibility of pests and pathogens switching between closely related eucalypt hosts. Over the past ten years, there have been anecdotal reports of increasing levels of Mycosphaerella leaf disease (MLD) in E. globulus plantations in south-western Australia. This increase in disease level is of concern to the industry. To date there have been no comprehensive studies into the taxonomy, biogeography and population genetics of MLD in south-western Australia. This thesis investigated the impact of MLD in south-western Australia with a focus on its impact, taxonomy, biogeography and population genetics. It is the first study worldwide to quantify the relative impact of different Mycosphaerella species in a regional plantation estate. A survey of pest, disease and nutritional disorders (Chapter 2) found that MLD was the most severe and frequently occurring, single taxonomic health threat to 1 and 2-year-old E. globulus plantations in south-western Australia. For the first time, this survey identified and quantified the impact of pest and disease damage to E. globulus plantations in the region. There were differences in the disease levels between plantations and this was due to initial Mycosphaerella species composition and inoculum level, and local climatic conditions favourable for disease, rather than to the provenance planted or the nutritional status of the individual plantations. The survey for Mycosphaerella pathogens of eucalypts (Chapter 3) identified two new species of Mycosphaerella (M. ambiphylla and M. aurantia) and extended the known geographic range of eight other species (M. cryptica, M. gregaria, M. lateralis, M. marksii, M. mexicana , M. nubilosa, M. parva and M. suberosa). Of these: M. lateralis and M. mexicana were new records for Australia; and M. gregaria, M. nubilosa and M. parva were new records for Western Australia. A new anamorph, Phaeophloeospora ambiphylla was described and linked to M. ambiphylla. The occurrence of these new species and disease records in south-western Australia is significant for the plantation-eucalypt industry worldwide. The finding of two new species highlighted the need to quantify the disease impact of these on eucalypt plantations; and the extension of the range the remaining species raised important quarantine issues, concerned with the movement of plant material between regions and countries. The biogeographical investigation of Mycosphaerella (Chapter 4) identified that the most widespread and serious cause of MLD in south-western Australia is M. cryptica. In addition to occurring on the exotic E. globulus, it also occurs on two of the three important indigenous forestry eucalyptus species in this region. That is, on E. diversicolor, and E. marginata, but not on Corymbia calophylla. In terms of the plantation estate of E. globulus, however, M. nubilosa is the most widespread pathogen. The current study found that MLD on E. globulus is a complex of several different species, whereas, on E. diversicolor and E. marginata it is caused by only M. cryptica. Two species, M. cryptica and M. marksii were found commonly on adult E. globulus leaves. Although M. cryptica was the most frequent and serious cause of disease on adult leaves, M. marksii levels appear to be increasing and the future epidemiology of this pathogen should be closely monitored. There is some concern that these two MLD species could become an economically important problem on adult leaves of E. globulus. At present severe levels of MLD is significantly more common on juvenile than on adult foliage. The phylogenetic analysis (Chapter 5), based on ITS rDNA sequences from the present study and those obtained from GenBank accessions, found that Mycosphaerella is an assemblage of largely polyphyletic anamorph genera. Ten distinct clades emerged from the analysis. With the exception of the Dissoconium and the M. recutita clade, which comprised of two and one species respectively, none were comprised entirely of one anamorph genus alone. The anamorph genera represented were often dispersed across more than one clade, indicating that these anamorphs have arisen separately in different phylogenetic lineages. Cercospora, Stenella and Uwebraunia anamorphs each occurred in more than one separate clade. Although on the basis of rDNA sequence data Mycosphaerella appeared mostly monophyletic there was some evidence that the Mycosphaerella genus may be polyphyletic. This was particularly evident from the Dissoconium clade which grouped as closely to the outgroup Botryosphaeria taxon as it did with the remaining Mycosphaerella species. It was argued that a multi-gene phylogeny, which includes sequencing many species in other genera aligned with Mycosphaerella, is required in order to satisfactorily answer the question of whether Mycosphaerella is truly monophyletic. The phylogenetic analysis also showed that the taxonomy of Mycosphaerella based on ITS sequence data needs further clarification. Some species that are morphologically distinct, such as M. vespa and M. molleriana, shared identical ITS sequences. Other morphologically distinct species differed by as little as one or two nucleotides. Yet in other cases, the sequence variation amongst isolates from the same species differed substantially. Much of this variation in M. cryptica and other species was attributed to poorly edited sequences that had been lodged with GenBank. It was postulated that although a part of the remaining variation reflected the existence of cryptic species, some was likely to be genuine intra-species differences. It was concluded that further genes need to be sequenced, and more standardised cultural studies conducted in order to define species boundaries within Mycosphaerella. Based on the ITS rDNA sequence data, two different molecular methods for the identification of Mycosphaerella species from eucalypts were developed (Chapter 6). The first of these was a PCR-RFLP method that enabled the identification of Mycosphaerella species present on eucalypts in south-western Australia. A key is provided, which enabled the identification of species on a combination of PCR-RFLP DNA fragment migration patterns and a small number of morphological features. This key enables the identification of Mycosphaerella species more easily than keys that rely on morphological features alone. Therefore, this has made it easier for non-Mycosphaerella specialists to identify species from this genus. The second molecular method developed for the identification of Mycosphaerella species was that of primers that selectively amplify the DNA of M. cryptica and M. nubilosa, the two most important causes of MLD (Chapter 6). This will allow the rapid identification of these two species by non-specialists in Mycosphaerella taxonomy. The primers from the current study will also enable early diagnosis of the possible causal organism of MLD in a plantation. Once the use of these primers for amplifying DNA from leaf tissue has been optimised, they will also facilitate studies into the early infection process of M cryptica and M. nubilosa. For example, the presence of the pathogen may be detected prior to the appearance of symptoms. Studies may be conducted to determine the length of a hemi-biotrophic phase, and the extent of tissue colonisation both spatially and temporally, beyond the necrotic lesion in these two Mycosphaerella species. Previously, such studies have been hampered by the slow growth rate of these fungi in culture and the lack of media that would allow their selective isolation and detection by directly plating diseased and non-diseased host tissue. This study has clearly indicated that Mycosphaerella species are the major disease threat to E. globulus plantations in Western Australia. It has also shown that over the relatively short period of time of less than ten years the number of species recorded has increased from three to ten, and that disease severity has increased in plantations. It is therefore critical to continue the research on this genus in order to understand the biology, epidemiology and population genetics of this pathogen. This is necessary in order to inform tree selection and silvicultural practise that will minimise the future impact of MLD. This is particularly important if the industry moves towards clonal and hybrid forestry as has occurred elsewhere in the world. This study has laid the foundations for future research on this disease through the elucidation of the taxonomy of Mycosphaerella in south-western Australia and by providing some important molecular tools for its diagnosis and further study.

In this study, the relative influences of selection, gene flow, and other evolutionary forces on the spatial structure of genetic variation within a eucalypt species complex (the spotted gums: genus Corymbia, section Politaria) were assessed. The study investigated the spatial genetic structure among four putative species of spotted gum (broad-scale), as well as within a single population (fine-scale)of one species, using both molecular and quantitative markers. The spotted gum complex occurs naturally across a range of 2500 km in eastern Australia. Spatial genetic variation within and between the four putative spotted gum species was examined using both chloroplast and nuclear markers. No significant differentiation was found between the three northern species of the complex, C. citriodora, C. variegata and C. henryi. The southern species, C. maculata, shared no haplotypes with any of the three northern species. These results disagree in part with those reported in a previous allozyme based study in which C. henryi was found to be significantly divergent from C. variegata (with which it is sympatric) and more closely aligned with C. maculata. Re-analysis of the allozyme data provided evidence of selection acting at the PGM2 locus within populations of C. variegata and C. henryi. The exclusion of this locus from the data set led to concordance between the cpDNA and nDNA analyses. Restricted gene flow and evidence of isolation by distance were identified as the dominant processes influencing the contemporary distribution of the cpDNA haplotypes. No geographic structure of haplotypes was found and complex genealogical relationships between haplotypes indicated the combined effects of past fragmentation, range expansion and possible long distance dispersal events. The variation and spatial structure in both neutral molecular markers and quantitative genetic traits were compared to explore the relative influences of dispersal and selection within a single eucalypt population. Both mature trees (n=130) from a natural population of C. variegata and their progeny (n=127) were sampled. A very high outcrossing rate (98%) was estimated for the population based on data from seven microsatellite loci. This suggested regular pollen–mediated gene flow into the population, further supported by the observed high levels of genetic diversity and polymorphism. Significant positive spatial structure was found between parent trees occurring up to 150 m apart in the natural forest, although genetic distance between these individuals suggested limited relatedness (i.e. less than half-sib relatedness). The effect of pollen-mediated gene flow appears, therefore, to swamp any effect of nearest neighbour inbreeding which has been reported in other studies of eucalypt populations and has been attributed to limited seed dispersal. Resistance to the fungal disease Sporothrix pitereka (Ramularia Shoot Blight) was measured on progeny from each of the population study trees. Substantial resistance variability was found, along with a high estimate in heritability of resistance (0.44 ± 0.06), indicating significant additive genetic variation within the population. Spatial analysis showed no significant spatial structure with resistant and susceptible genotypes apparently distributed randomly throughout the population. The lack of concordance between the molecular and quantitative markers suggests that there may be a cost to resistance. Temporal variation in the severity of disease outbreaks may have then led to differential selection of seedlings across many generations, maintaining variability in disease resistance and facilitating the apparent random distribution of disease resistant and susceptible genotypes throughout the population. C. variegata is an important commercial forestry species. The identification of strong genetic control in the disease resistance trait, as well as significant adverse genetic and phenotypic correlations between susceptibility and growth traits, will aid future breeding programs. Controlled crosses between resistant genotypes from this population should result in strong genetic gains in both resistance and growth, with little costs associated with inbreeding depression due to the highly outcrossed nature of the population.

A alta demanda por madeira de eucalipto para diversas finalidades traz a necessidade da expansão de plantios para áreas em condições de déficit hídrico, o que leva o interesse de entender os processos fisiológicos relacionados ao crescimento da árvore, para possibilitar uma alta produtividade das florestas nessas áreas. Com base nessas informações, o objetivo deste trabalho foi avaliar o efeito da variação de níveis de restrições hídricas em clones de Eucalyptus spp. plantados em diferentes condições edáficas, pelo estudo das respostas ecofisiológicas, para isso foram instalados em janeiro 2012 dois experimentos na Estação Experimental de Ciências Florestais de Itatinga (EECFI) pertencente a Escola Superior de Agricultura \"Luiz de Queiroz\" (ESALQ) - USP, o experimento 1 foi instalado no solo classificado como Latossolo vermelho distroférrico típico A moderado textura argilosa (LVdf) e o experimento 2 no solo Latossolo vermelho distrófico típico A moderado textura argilosa (LVd-1).Cada experimento foi implantado em blocos casualizados em arranjo fatorial de 6 x 3, seis clones de eucalipto (COP 1404, COP 1407, AEC 1528, AEC 0042, AEC 0224, AEC 0144) e três espaçamentos (3m x1m, 3mx2m, e 3mx4m), com seis repetições, e parcelas quadradas constituídas por 25 plantas, sendo as nove plantas centrais consideradas como a área útil de medição. Foram realizadas avaliações das variáveis: DAP (cm), altura total (m), comprimento da copa (m) e índice de área foliar (IAF m2/m2) trimestralmente, no período de 21 até 37 meses de idade para as variáveis altura total e DAP, e o comprimento da copa e IAF a partir do mês 27. Para a mensuração do IAF foram utilizados dois equipamentos LAI-2000, onde a coleta de dados foi fora e sob o dossel. O folhedo foi coletado mensalmente em todas as parcelas. A avaliação da eficiência e uso de água foi aos 29 e 35 meses, analisando área foliar e as caraterísticas estomáticas em quatro blocos, nos quais três árvores foram amostradas sistematicamente. Para avaliação no incremento de diâmetro no tronco, se instalaram faixas dendrométricas em duas árvores por parcela e as leituras foram quinzenais, sendo correlacionadas com variáveis climáticas no período de 15 e 45 dias de defasagem. Os clones que apresentaram melhor desenvolvimento e estratégia do uso da água foram AEC 1528, AEC 0144 e AEC 0042 obtendo como respostas: maior DAP, altura total, comprimento da copa, área foliar, diâmetro estomático, e menor IAF e concentração de estômatos. Em relação ao peso de folhedo depositado verificou-se que a tendência de deposição oscilou no decorrer do tempo em função da fenologia da planta. Na dinâmica de crescimento cambial os incrementos apresentaram correlações com as variáveis climáticas, principalmente com a precipitação pluviométrica, quanto maior a defasagem maior a correlação. Correlacionando todas as variáveis, os clones apresentaram distintos padrões de respostas ecofisiológicas. / Eucalypts plantations are expanding to drought áreas in Brazil in order to attend the high demand of eucalypts wood for various purposes. Therefore, the understanding the physiological process related to tree growth in this condition is one of the research priorities. This study aimed to evaluate the effect of ecophysiological responses to water restrictions levels in growth of Eucalyptus spp clones, planted in different soil conditions. The two field experiments were planted in January 2012 at the Itatinga Experimental Station, College of Agriculture \"Luiz de Queiroz\" (ESALQ), São Paulo State University. Experiment 1 was planted on a site which the soil is classified as \"A moderate typical dystrophic Red Latosol with clay texture (LVdf)\" and experiment 2 on \"A moderate typical dystrophic Red Latosol with clay texture (LVd- 1)\". The experiments were established in a randomized block design with factorial 6 x 3 arrangement [six eucalypts clones (COP 1404, COP 1407, AEC 1528 AEC 0042, AEC 0224, AEC 0144) and three spacings (3m x1m, 3mx2m and 3mx4m)], with six replications, and square plots (5x5 trees). The measurements were carried out on the nine central trees. From the 21 to 37 months of age, the following variables were assessed every three months: DBH (diameter at breast height in cm), height (m) and crown length (m). Leaf area index (LAI m2 / m2) was evaluated every three months after 27 months of age. Two LAI-2000 equipments were used to measure the LAI, one under and another out of the canopy. Litter was collected monthly on all plots. The efficiency of water use was evaluated at 29 and 35 months of age, based on leaf area and stomatal characteristics of samples collected in three trees sampled systematically in four blocks. Dendrometer belts were used to evaluate the diameter growth of two trees per plot. Data collected fortnightly from dendrometers belts were correlated with climatic variables with 15 and 45-da lags. AEC 1528, AEC 0144 and AEC 0042 clones showed higher DBH, total height, crown length, leaf area, stomatal diameter and lower IAF and stomatal concentration, showing better strategy of water use and growth. Deposition of litter fluctuated over time and varied with the tree phenology. Cambium growth dynamics correlated with climate variables, especially with the rainfall. Higher correlations were observed with higher measured lag. Clones showed distinct patterns of ecophysiological responses when the correlations of all variables were considered.

A produção de lodo de esgoto vem aumentando exponencialmente com a multiplicação das estações de tratamento de esgoto (ETEs) e a sua disposição final tem se tornado um problema sanitário preocupante. Por ser um resíduo rico em matéria orgânica e nutrientes, muitas pesquisas vêm sendo desenvolvidas na busca de alternativas ecologicamente mais adequadas para o seu descarte. Este trabalho teve como objetivo verificar as diferenças entre lodos de esgoto (biossólidos), produzidos em três diferentes Estações de Tratamento de Esgotos da região metropolitana de São Paulo, quando utilizados como adubo em plantações de Eucalyptus grandis. Procurou-se também avaliar a influência deste resíduo sobre a ciclagem de nutrientes e sobre a dinâmica de metais pesados no ecossistema florestal. O estudo foi realizado na Estação Experimental de Ciências Florestais da ESALQ/USP em Itatinga-SP, cujo solo é predominantemente arenoso e de baixa fertilidade natural. O delineamento experimental utilizado foi em blocos aleatorizados, com 4 repetições e cinco tratamentos, sendo eles: 1)Testemunha Absoluta (TA), sem nenhuma adubação; 2) Fertilização mineral convencional (FM); 3) Aplicação de 15 Mg ha-1 de lodo de esgoto da ETE de Barueri (LB); 4) 15 Mg ha-1 de lodo de esgoto da ETE de São Miguel (LSM); 5) 15 Mg ha-1 de lodo de esgoto da ETE do Parque Novo Mundo (LPNM). Todos os tratamentos com lodo de esgoto foram complementados com potássio mineral (KCl), visto que o lodo é deficiente neste nutriente. O LB e o LSM foram condicionados com polieletrólitos, mas o LPNM foi condicionado com cal hidratada e cloreto férrico. O efeito dos diferentes tratamentos sobre os eucaliptos foi avaliado através de: inventários florestais semestrais, nutrição foliar, estimativa do folhedo produzido mensalmente, estimativa semestral de folhedo acumulado sobre o solo, avaliação da decomposição do folhedo no campo através de bolsas decompositoras, reflexo dos lodos sobre a fertilidade do solo, estimativa da biomassa e do estoque de nutrientes e metais pesados nos componentes do tronco (Lenho+Casca), nas folhas e nas raízes finas dos eucaliptos. Observou-se que a adubação dos eucaliptos com os lodos propiciou, em média, um incremento do volume de madeira da ordem de 65%, superior à testemunha (sem adubação) e similar ao observado no tratamento com fertilização mineral. A concentração dos nutrientes nas folhas dos eucaliptos tratados com os lodos, aos 6 meses de idade, apresentou uma elevação significativa dos nutrientes N, P, Ca, Cu, Fe e Zn em relação à testemunha. Mas, aos 42 meses, observou-se a tendência geral de redução da concentração de todos os nutrientes nas folhas, independente dos tratamentos. A adição dos lodos estimulou em 75% a produção de folhedo pelos eucaliptos, bem como um maior acúmulo de folhedo sobre o piso florestal. Conseqüentemente, houve uma maior transferência de nutrientes, via folhedo, das copas dos eucaliptos para a camada de serapilheira. De maneira geral, a aplicação da FM e dos lodos de esgoto melhorou a fertilidade do solo na linha de plantio (ponto de aplicação), principalmente na camada entre 0 e 5 cm de profundidade. Todavia, poucas mudanças foram observadas na produção de raízes finas em função dos diferentes tratamentos. O lodo de esgoto, quando condicionado na ETE com cal hidratada, tende a elevar o estoque de cálcio em todos os componentes do sistema solo-planta-serapilheira, podendo a longo prazo causar desbalanço nutricional e impactos prejudiciais ao ecossistema. Nos tratamentos com lodo de esgoto, foi observada uma maior concentração de metais pesados, em comparação à testemunha, nas folhas: Cu, Zn e Ni; no folhedo: Cu e Zn; no solo: Cu e Zn (na linha de plantio) e Zn (na entrelinha de plantio), apenas na camada de 0-5 cm de profundidade e nas raízes finas: Zn e Ni. É imprescindível, portanto, se conhecer previamente a concentração dos diferentes elementos no lodo de esgoto, antes de sua aplicação em plantios florestais. O monitoramento nutricional das árvores e da ciclagem dos nutrientes são práticas de fundamental importância para o bom manejo deste resíduo e do empreendimento florestal. / The production of sewage sludge increased exponentially with the enlargement of sewage treatment plants (ETEs, by its acronym in Portuguese). The final disposal of this product has always been a sanitary problem. Since it is a residue rich in organic matter and nutrients, several researches have been carried out, looking for adequate ecological alternatives for its disposal. This study aims to verify the differences among the sewage sludge (biosolids) from three different sewage treatment plants in the metropolitan region of Sao Paulo when used as fertilizers in Eucalyptus grandis plantations. Moreover it seeks to assess the influence of this residue in the nutrients cycling and in the heavy metals dynamic in forestry ecosystems. This research was carried out in the Experimental Station of Forestry Sciences of ESALQ/USP in Itatinga, Sao Paulo, where the soil is mainly sandy and of low natural fertility. The experimental delineation was of randomized blocks, with 4 replications and 5 treatments: 1) control (TA) without fertilization; 2) mineral conventional fertilization (FM); 3) application of 15 Mg ha-1 of sewage sludge from Barueri ETE (LB); 4) 15 Mg ha-1 of sewage sludge from Sao Miguel ETE (LSM); 5) 15 Mg ha-1 of sewage sludge from Parque Novo Mundo ETE (LPNM). Since the sewage sludge lacks mineral potassium (KCl), it was added to all the treatments. The LB and the LSM were conditioned with polyelectrolyte, but the LPNM was conditioned with CaOH and with FeCl3. The sewage sludge was applied in the planting rows. The effect of the different treatments on the eucalyptus trees was assessed by: six-monthly forestry inventories, leafs nutrition, estimation of monthly production of leaf fall, six-monthly estimation of leaf fall stocked in the soil, assessment of the decomposition of leaf fall in the field with decomposition bags, reflex of the sludge over the soil fertility, estimation of the biomass and the stock of nutrients and heavy metals in the trunk (stem wood + bark), in the leaves and in the fine roots of the eucalyptus trees. It was observed that the fertilization with sludge favored in average the increase of the wood volume around 65%, higher that the control (without fertilization) and similar to what observed in the treatment with mineral fertilization. The concentration of N, P, Ca, Cu, Fe and Zn in the leaves of the eucalyptus treated with the sludge, when six months old, increased significantly compared with the control. When the trees, of all the treatments were 42 months old, there was a decrease in the concentration of all nutrients in the leaves. The addition of sludge stimulated in 75% the production of leaf fall, as well as its high accumulation in the forestry soil. Consequently, the nutrients transfer was high, by the leaf fall, from the top of the trees to the litter. In general, the application of FM and of sewage sludge improved the soil fertility in the inter row (application place), mainly in the depth 0-5 cm. However, few changes were observed in the fine roots production regarding the different treatments. The sewage sludge, when conditioned in the ETE with CaOH, tends to increase the calcium stock in all the components of the system soil-plantlitter, what in long term may cause a nutritional imbalance and harmful impacts to the ecosystem. In the treatments with sewage sludge, a higher concentration of heavy metals in the leaves was observed in comparison with the control: Cu, Zn and Ni; in the leaf fall: Cu and Zn; in the soil: Cu and Zn (in the planting rows) and Zn (between-tree rows), only in the depth 0-5cm and in the fine roots: Zn and Ni. Therefore, before the application of sewage sludge in forestry plantations it is essential to know the concentration of the different elements present in it. The nutritionalmonitoring of the trees and the nutrients cycling are fundamental practices of essential importance for the good management of this residue and for the forestry farmer

A alta demanda por madeira de eucalipto para diversas finalidades traz a necessidade da expansão de plantios para áreas em condições de déficit hídrico, o que leva o interesse de entender os processos fisiológicos relacionados ao crescimento da árvore, para possibilitar uma alta produtividade das florestas nessas áreas. Com base nessas informações, o objetivo deste trabalho foi avaliar o efeito da variação de níveis de restrições hídricas em clones de Eucalyptus spp. plantados em diferentes condições edáficas, pelo estudo das respostas ecofisiológicas, para isso foram instalados em janeiro 2012 dois experimentos na Estação Experimental de Ciências Florestais de Itatinga (EECFI) pertencente a Escola Superior de Agricultura \"Luiz de Queiroz\" (ESALQ) - USP, o experimento 1 foi instalado no solo classificado como Latossolo vermelho distroférrico típico A moderado textura argilosa (LVdf) e o experimento 2 no solo Latossolo vermelho distrófico típico A moderado textura argilosa (LVd-1).Cada experimento foi implantado em blocos casualizados em arranjo fatorial de 6 x 3, seis clones de eucalipto (COP 1404, COP 1407, AEC 1528, AEC 0042, AEC 0224, AEC 0144) e três espaçamentos (3m x1m, 3mx2m, e 3mx4m), com seis repetições, e parcelas quadradas constituídas por 25 plantas, sendo as nove plantas centrais consideradas como a área útil de medição. Foram realizadas avaliações das variáveis: DAP (cm), altura total (m), comprimento da copa (m) e índice de área foliar (IAF m2/m2) trimestralmente, no período de 21 até 37 meses de idade para as variáveis altura total e DAP, e o comprimento da copa e IAF a partir do mês 27. Para a mensuração do IAF foram utilizados dois equipamentos LAI-2000, onde a coleta de dados foi fora e sob o dossel. O folhedo foi coletado mensalmente em todas as parcelas. A avaliação da eficiência e uso de água foi aos 29 e 35 meses, analisando área foliar e as caraterísticas estomáticas em quatro blocos, nos quais três árvores foram amostradas sistematicamente. Para avaliação no incremento de diâmetro no tronco, se instalaram faixas dendrométricas em duas árvores por parcela e as leituras foram quinzenais, sendo correlacionadas com variáveis climáticas no período de 15 e 45 dias de defasagem. Os clones que apresentaram melhor desenvolvimento e estratégia do uso da água foram AEC 1528, AEC 0144 e AEC 0042 obtendo como respostas: maior DAP, altura total, comprimento da copa, área foliar, diâmetro estomático, e menor IAF e concentração de estômatos. Em relação ao peso de folhedo depositado verificou-se que a tendência de deposição oscilou no decorrer do tempo em função da fenologia da planta. Na dinâmica de crescimento cambial os incrementos apresentaram correlações com as variáveis climáticas, principalmente com a precipitação pluviométrica, quanto maior a defasagem maior a correlação. Correlacionando todas as variáveis, os clones apresentaram distintos padrões de respostas ecofisiológicas. / Eucalypts plantations are expanding to drought áreas in Brazil in order to attend the high demand of eucalypts wood for various purposes. Therefore, the understanding the physiological process related to tree growth in this condition is one of the research priorities. This study aimed to evaluate the effect of ecophysiological responses to water restrictions levels in growth of Eucalyptus spp clones, planted in different soil conditions. The two field experiments were planted in January 2012 at the Itatinga Experimental Station, College of Agriculture \"Luiz de Queiroz\" (ESALQ), São Paulo State University. Experiment 1 was planted on a site which the soil is classified as \"A moderate typical dystrophic Red Latosol with clay texture (LVdf)\" and experiment 2 on \"A moderate typical dystrophic Red Latosol with clay texture (LVd- 1)\". The experiments were established in a randomized block design with factorial 6 x 3 arrangement [six eucalypts clones (COP 1404, COP 1407, AEC 1528 AEC 0042, AEC 0224, AEC 0144) and three spacings (3m x1m, 3mx2m and 3mx4m)], with six replications, and square plots (5x5 trees). The measurements were carried out on the nine central trees. From the 21 to 37 months of age, the following variables were assessed every three months: DBH (diameter at breast height in cm), height (m) and crown length (m). Leaf area index (LAI m2 / m2) was evaluated every three months after 27 months of age. Two LAI-2000 equipments were used to measure the LAI, one under and another out of the canopy. Litter was collected monthly on all plots. The efficiency of water use was evaluated at 29 and 35 months of age, based on leaf area and stomatal characteristics of samples collected in three trees sampled systematically in four blocks. Dendrometer belts were used to evaluate the diameter growth of two trees per plot. Data collected fortnightly from dendrometers belts were correlated with climatic variables with 15 and 45-da lags. AEC 1528, AEC 0144 and AEC 0042 clones showed higher DBH, total height, crown length, leaf area, stomatal diameter and lower IAF and stomatal concentration, showing better strategy of water use and growth. Deposition of litter fluctuated over time and varied with the tree phenology. Cambium growth dynamics correlated with climate variables, especially with the rainfall. Higher correlations were observed with higher measured lag. Clones showed distinct patterns of ecophysiological responses when the correlations of all variables were considered.

Eucalyptus species, particularly stringybarks, which produce hard, durable wood are potentially useful in New Zealand, but most species are site sensitive. Twelve species (E. agglomerata, E. baxteri, E. botryoides, E. cladocalyx, E. globoidea, E. microcorys, E. muelleriana, E. nitens, E. obliqua, E. pilularis, E. regnans and E. saligna) were compared on four hill country microsites; upper and lower slope on sunny and shady aspects. Assessments included survival, foliar macro-nutrients, diameter at breast height (DBH), height, stem form, basic wood density and health to age 5 years. Site monitoring included solar radiation, temperature, rainfall and exposure. Foliar nutrients were strongly influenced by species and moderately influenced by microsite. Inter-nutrient and nutrient-growth correlations were identified and discussed. Subgeneric differences in nutrient profile were analysed with the aid of principal components analysis. Solar radiation and temperature were seasonal on both aspects but higher on the sunny face than the shady. Aspect differences were moderate, being greatest in the winter and least in the summer. A strongly seasonal growth pattern resulted, maximum DBH and height increments occurring in the spring and summer respectively. Growth was least in the winter. Seasonal and aspect effects on growth were related to solar radiation. Height and DBH (5 years) were significantly higher on the sunny face than the shady in all species. Slope position did not influence height but DBH on the lower slope was less than on the upper. Aspect had little influence on basic wood density and form. Species differed in growth, form and basic density. E. nitens was the most productive species but basic density was low. Conversely, density was highest in E. cladocalyx, among the least productive species. The stringybarks were intermediate in growth, form and density. The relationships between growth, form, density and environmental factors were explored with canonical correlation. Two species (E. botryoides and E. saligna) were adversely affected by possum browsing and infection by a leaf gall wasp (Ophelimus eucalypti). Discussion of the results includes consideration of the merits of assessments of relatively young trees as well as implications for tree growers.