A study was undertaken to compare growth potential of three Eucalyptus species of natural origin in South Eastern Australia, with commercially grown species on mid and high altitude temperate sites in the summer rainfall growing zones in South Africa. The three species were Eucalyptus globulus subsp. bicostata (E. bicostata), Eucalyptus cypellocarpa and Eucalyptus nobilis. Nine sites were selected to represent the growing areas of South Africa experiencing cold winter drought with occasional snow falls. Improved, commercially grown pure Eucalyptus species and interspecific hybrid clones were included as controls in the trials to give comparative growth performances on specific sites. Both balanced and unbalanced lattice designs were used to evaluate the growth potential of the unimproved Australian species and the improved commercial controls incorporated into the trials. Volume production and basal area growth were assessed for the three species at all sites. However, only three sub species E.globulus (E. bicostata, E. maidenii and E. globulus) showed varying levels of disease (Mychosphaerella nobilosa) infestation and this was therefore assessed in trials at 12 and 30 months respectively, and correlation analysis was used to study the relationship between the impact of disease infestation and growth performance. It was found that negative phenotypic correlations existed between the levels of infection and tree growth. ie greater infection slower growth. Evaluation of genotype x environment interaction (GXE) revealed that this did not exist in the E. bicostata nor E. nobilis populations, and therefore one population of each species can be developed for all the sites tested. E. cypellocarpa was the only species that showed some GXE interaction implying that separate populations to be developed for different sites. Contrary to what was expected, unimproved Eucalyptus species being investigated performed equally as well as the improved commercial species included as controls, thus providing potential for commercial deployment with selection and breeding. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.

To produce high quality paper, lignin should be removed from the pulp. Quantification of lignin concentrations using standard wet chemistry is accurate but time consuming and costly, thus not appropriate for a large number of samples. The ability of hyperspectral remote sensing to predict foliar lignin concentrations could be utilized to estimate wood lignin concentrations if meaningful relationships between wood and foliar chemistry are established. LAI (leaf area index) is a useful parameter that is incorporated into physiological models in forest assessment. Measuring LAI over vast areas is labour intensive and expensive; therefore, LAI has been correlated to vegetation indices using remote sensing. Broadband indices use average spectral information over broad bandwidths; therefore details on the characteristics of the forest canopy are compromised and averaged. Moreover, the broadband indices are known to be highly affected by soil background at low vegetation cover. The aim of this study is to determine foliar and wood lignin concentrations of Eucalyptus clones using hyperspectral lignin indices, and to estimate LAI of Eucalyptus clones from narrowband vegetation indices in Zululand, South Africa Twelve Eucalyptus compartments of ages between 6 and 9 years were selected and 5 trees were randomly sampled from each compartment. A Hyperion image was acquired within ten days of field sampling, SI and LAI measurements. Leaf samples were analyzed in the laboratory using the Klason method as per Tappi standards (Tappi, 1996-1997). Wood samples were analyzed for lignin concentrations using a NIRS (Near Infrared Spectroscopy) instrument. The results showed that there is no general model for predicting wood lignin concentrations from foliar lignin concentrations in Eucalyptus clones of ages between 6 and 9 years. Regression analysis performed for individual compartments and on compartments grouped according to age and SI showed that the relationship between wood and foliar lignin concentration is site and age specific. A Hyperion image was georeferenced and atmospherically corrected using ENVI FLAASH 4.2. The equation to calculate lignin indices for this study was: L1R= ~n5il: A'''''y . 1750 AI680 The relationship between the lignin index and laboratory-measured foliar lignin was significant with R2 = 0.79. This relationship was used to calculate imagepredicted foliar lignin concentrations. Firstly, the compartment specific equations were used to calculate predicted wood lignin concentrations from predicted foliar lignin concentrations. The relationship between the laboratorymeasured wood lignin concentrations and predicted wood lignin concentrations was significant with R2 = 0.91. Secondly, the age and site-specific equations were used to convert foliar lignin concentration to wood lignin concentrations. The wood lignin concentrations predicted from these equations were then compared to the laboratory-measured wood lignin concentrations using linear regression and the R2 was 0.79 with a p-value lower than 0.001. Two bands were used to calculate nine vegetation indices; one band from the near infrared (NIR) region and the other from the short wave infrared (SWIR). Correlations between the Vis and the LAI measurements were generated and . then evaluated to determine the most effective VI for estimating LAI of Eucalyptus plantations. All the results obtained were significant but the NU and MNU showed possible problems of saturation. The MNDVI*SR and SAVI*SR produced the most significant relationships with LAI with R2 values of 0.899 and 0.897 respectively. The standard error for both correlations was very low, at 0.080, and the p-value of 0.001. It was concluded that the Eucalyptus wood lignin concentrations can be predicted using hyperspectral remote sensing, hence wood and foliar lignin concentrations can be fairly accurately mapped across compartments. LAI significantly correlated to eight of the nine selected vegetation indices. Seven Vis are more suitable for LAI estimations in the Eucalyptus plantations in Zululand. The NU and MNU can only be used for LAI estimations in arid or semi-arid areas. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.