A short history of the electronic data processing development in North America is given. The basic principles of computers and data processing systems are analysed and a brief description of ALWAC III-E and IBM 1620 computers is provided. Sufficient information is given to acquaint professional foresters or research workers in forestry with the basic knowledge required to understand where and how computing can be applied in their work. The major factors that govern how and when to use a computer are: required speed and accuracy, size, repetitiveness, and complexity of the calculation. It is pointed out that the advantages of an electronic computer are: speed, accuracy, versatility, reliability and memory. The disadvantages are: high rental cost, extra cost for transposing data on cards or tape, and complicated program writing. In forestry the main fields of electronic computer applications are: Management Mensuration Utilization Logging engineering Research Examples are presented for each field in the text, typical programs are appended, and sources of further information are noted. It is concluded that in the future the importance of electronic computers will increase in forestry practices; however, it will remain only a tool and cannot replace the forester. / Forestry, Faculty of / Graduate

Orientador: Sérgio Campos / Coorientador: Roberta Thays dos Santos Cury / Banca: Felipe Wanderley de Amorim / Banca: Renata Cristina Batista Fonseca / Resumo: A conversão de florestas naturais em pastagens, lavouras ou reflorestamentos homogêneos com espécies exóticas, pode influenciar processos ecológicos importantes alterando a dinâmica florestal. O trabalho teve como objetivo avaliar se reflorestamentos homogêneos de Pinus elliottii influenciam a remoção de sementes em uma vegetação secundária de Floresta Ombrófila Mista Montana adjacente. Assim, formulamos três hipóteses: (1) a remoção de sementes será maior na vegetação secundária de Floresta Ombrófila Mista Montana adjacente ao plantio de Pinus elliottii, em especial, onde as plantações se encontram em estágio inicial de desenvolvimento; (2) a remoção de sementes na vegetação secundária de Floresta Ombrófila Mista Montana será maior quanto mais distante da borda com plantio de Pinus elliottii; e (3) a remoção de sementes será diferente entre as espécies de Syagrus romanzoffiana, Araucaria angustifolia e Pinus elliottii. Foram selecionadas seis áreas de plantios de Pinus elliottii adjacentes a vegetação secundária de Floresta Ombrófila Mista Montana. Em cada área foram instalados cinco pontos amostrais, distribuídos ao longo de um transecto a uma distância de 0, 10, 25, 50 e 100 metros da borda florestal. Em cada ponto foram depositadas 13 sementes de cada espécie analisada. O monitoramento das sementes foi realizado após dois, sete, nove, 14 e 21 dias. No geral a taxa de remoção foi elevada para todas as espécies (100% para espécie Syagrus romanzoffiana, 98% para Pinus elliot... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Conversion of natural forests to pasture, crop or homogeneous reforestation with exotic species can influence important ecological processes by changing the forest dynamics. The objective of this work was to evaluate the effects of Pinus elliottii plantation on seed predation in a Mixed Ombrophilous Montane secondary forest. Thus, we formulate three hypotheses: (1) seed removal will be greater in the Mixed Ombrophilous Montane secondary forest adjacent to Pinus elliottii plantation, especially where the plantations are in early stages; (2) seed removal will be greater in the Mixed Ombrophilous Montane secondary forest farther from the forest edge; and, (3) seed removal will be different among Syagrus romanzoffiana, Araucaria angustifolia and Pinus elliottii species. Six Pinus elliottii areas adjacent to Mixed Ombrophylous Montane secondary forest were selected. In each area, five plots were distributed along 0, 10, 25, 50 and 100 meters from the forest edge. Were deposited 13 seeds by species in each plot. Seeds were monitored during two, seven, nine, 14 and 21 days. In general the removal rate was high for all species (100% for Syagrus romanzoffiana, 98% for Pinus elliottii and 49% for Araucaria angustifolia). Similarly, all distances from the forest edge showed high seed removal, however, Araucaria angustifolia showed reduced seed removal at the edge, with 33% of removal at 0 m against 70% at 100 m. These rates indicate the presence of forest-associated fauna, which may cause predation and/or secondary dispersal. The reduced seed removal of Araucaria angustifolia, a key species for Atlantic Forest, on the forest edge, may indicate losses in the wildlife associated with the forest edge adjacent to the homogeneous planting. In addition, the removal of Pinus elliottii seeds in the forest, if predated, may indicate a reduction of their invasive potential in natural areas. / Mestre

Generally it is not adequate to calculate an allowable cut for a property by only one formula or method. Usually it is preferable to utilize all the information available with as many suitable formulae or methods as possible to obtain reasonable estimates of the yearly utilization rates by several approaches. For the University Research Forest fifteen different formulae and methods were selected for comparison, because their basic assumptions appeared applicable to this forest. The methods and formulae tested were: Methods: Area regulation, Area-volume check, Area-volume allotment, Barnes’ and H. A. Meyer's. Formulae: Austrian, Black Hills, Grosenbaugh, Hanzlik, Hundeshagen, Kemp, W. H. Meyer, S. Petrini (compound and simple interest) and Von Mantel. Appropriate inventory techniques were developed in order to collect the necessary information regarding rates of growth, mortality and numbers of trees per acre by diameter classes. Present and future decadal growing stocks were estimated. Simple and compound growth rates, including and excluding ingrowth, for all types were calculated separately for stands over eighty years of age and for stands under eighty years. The inventory was based on the areas and estimates taken from 1961 aerial photographs supplemented by both temporary and permanent sample plots, employing primarily the principles of the point sampling techniques as described by L. R. Grosenbaugh. After substituting the actual data into the formulae and various methods, allowable cut estimates for 3.1, 9.1, 11.1, and 13.1 inches minimum diameter limits were calculated. Allowances were made for an intermediate standard of utilization and for waste, breakage and decay. Considering the inventory and the allowable cut calculations it was found that: 1. Simple area regulation will lead to undesirably large fluctuations in allowable cut. 2. Volume formulae are useful means of determining the yearly harvest volume, though the distribution of the cut on the ground requires definition in terms of area as well. 3. Neither area nor volume control can be used exclusively. Some combination and integration is usually necessary in actual practice. In the case of the Research Forest this can be applied most conveniently by following the area-volume computation basis. / Forestry, Faculty of / Graduate

The thesis had two main objectives: namely to provide information on the sound attenuating abilities of tree species of the lower mainland region of British Columbia and to ascertain what stand characteristics cause trees to attenuate sound. After an extensive literature review an experiment was designed to investigate sound attenuation in eighteen tree stands, comprised of four species, at three distances, for eight different sound frequencies. The exerimental work was done during the winter of 1969 and the summer of 1970. Prior to this the tree stands were enumerated and various tree parameters measured. No patterns could be found which significantly correlated the measured stand characteristics with the amount of sound attenuated. Little significant difference was found between the summer and winter attenuations and it was found that stands reacted independently of the season. Tables are presented in the Appendix showing the attenuations for each stand, at each distance and for each frequency. Mean values together with their standard deviations are given for all stands within a species. Suggestions are given for future work on this topic and the implications of the results on various design fields are discussed. / Forestry, Faculty of / Graduate

The objectives of the study were to examine the socio-economic impact of outsourcing on forest-dependent communities, to evaluate the current outsourcing management system in Mondi Forests, and to assess the financial impact (costs savings) of outsourcing on Mondi Forests: Natal Region in KwaZulu-Natal. Participatory Rural Appraisal exercises were used to assess the socio-economic impact of outsourcing on forest-dependent communities. A questionnaire was then used on a sample of Mondi Forests personnel to evaluate the current outsourcing management system in Mondi Forests. Finally, cash-flow trends were used to assess the financial impact (costs savings) of outsourcing on Mondi Forests, Natal Region. Activities that have been outsourced include transport, harvesting operations, silviculture operations, security services, mechanical services, training, payroll services and information systems. Results show that outsourcing has impacted negatively on the livelihoods of some of the forest-dependent communities sampled. The negative impacts are mainly associated with a reduction in hygiene services offered to these communities and an increase in unemployment in some of these villages. Forest-dependent communities perceive outsourcing as the cause of poor relationship between the rural communities, forest companies and contractors as well as being the cause of high unemployment rates. Mondi Forests' personnel perceive that outsourcing goes beyond costs savings to include redirecting scarce resources toward core business activities. Lower morale and insecurity among forest staff members and negative views of the forestry companies by rural communities, unions and government departments were perceived as the disadvantages of outsourcing. Uncertainty with regards to employment continuity and social problems (e.g. increased forest fires, poor relationship with local communities) were perceived as outsourcing risks. Results show that Mondi Forests has implemented a number of strategies in order to reduce some of these risks and disadvantages by giving preference to their ex-employees when offering contracts, by providing start-up capital to emerging black contractors, and by initiating community development programmes in order to uplift the standard of living of the forest-dependent communities. Mondi Forests' personnel suggested that forest management. accounting, conservation management, and human resources are the best candidates for future outsourcing, since most other forest organizations in the world are already outsourcing them successfully. Most of these activities are still kept in-house in Mondi Forests. Results also show that outsourcing can be used with other rationalization methods to save costs. This is because costs savings in Mondi Forests: Natal Region, since 1998 to 2001 were .not only due to outsourcing, but also to some other management decisions such as reduced fertilizer and pesticides use. The total costs savings were R14.5 million from 1998 to 2001. Results support the need to strengthen the current rural development programmes in Mondi Forests, and to the establish Community Liaison Forums to improve communication with rural communities and to start community development programmes. A contractor upliftment programme was also recommended for developing the emerging black contractors. Lastly, company/contractor agreements must be reviewed in order to ensure that social responsibility aspects are appropriately managed. Outsourcing relationships need to consider the economic, environmental and social effects in order to be sustainable. / Thesis (M.Env.Dev.)-University of Natal, Pietermaritzburg, 2001.

Assessment of forest structural attributes has major implications in the management of forestry by providing information of ecological and economic importance. The traditional methods of assessment involve collecting data in the field and are regarded as labour-intensive and expensive. In plantation forestry, field campaigns are generally time consuming and costly, and may compromise profit maximisation. The introduction of lidar (light detection and ranging) remote sensing in forestry has shown promise to add value to the traditional field inventories mainly through large spatial coverages in a timely and cost-effective manner. Lidar remote sensing is an advanced system capable of acquiring information in both the vertical and horizontal dimensions at relatively high resolutions. Numerous studies have established that these qualities of lidar data are suited to estimating forest structural attributes at acceptably high accuracies. The generic approach in most studies is to use lidar data in combination with field data. Such an approach still warrants a high cost of inventory. It is therefore useful to explore alternative methods that rely primarily on lidar data by reducing the necessity for field-derived information. The aim of this study was to derive structural attributes of even-aged Eucalyptus grandis forest plantations using lidar data. The attributes are of significance to timber resource assessments and include plot-level tree height attributes, stems per hectare (SPHA), and volume. The surveyed field data included tree counting and measurement of tree height and diameter at breast height for sample plots. Volume was then calculated using standard allometric models. Small-footprint lidar data of the plantations were also acquired coincident with the field inventories. Mean tree height and dominant height were estimated at a range of simulated lidar point densities between 0.25 points/m2–6 points/m2. Various plot-level distributional metrics were extracted from height values of lidar non-ground points and related with field mean and dominant height values using stepwise regression analysis. The results showed that both attributes could be estimated at high accuracies with no significant differences arising from variations in lidar point density. Estimation of SPHA relied on the exploration of semi-variogram range as a mean window size for applying local maxima filtering to the lidar canopy height surface. A comparative approach of window size determination used pre-determined within-row tree spacing, based on planting information. Two secondary objectives were addressed: comparing spatial resolutions of canopy height surfaces interpolated from non-ground height values and comparison of lidar point densities simulated at three levels. Comparison of spatial resolutions of canopy height surfaces were performed at 0.2 m, 0.5 m, and 1 m using a lidar point density of 5 points/m2. The results indicated that 0.2 m is the most appropriate resolution for locating trees and consequently deriving SPHA. Canopy height surfaces of 0.2 m resolution were created at simulated densities of 1 point/m2, 3 points/m2, and 5 points/m2. While all estimates were negatively biased relative to field-observed SPHA, lidar densities of 3 points/m2 and 5 points/m2 returned similar accuracies, which were both superior to 1 point/m2. It was concluded that 3 points/m2 was sufficient to achieve the accuracy level obtained from higher lidar point densities. Plot-level mean height, dominant height, and volume of trees were estimated for trees located using local maxima filtering approaches at the three lidar point densities. Mean height and dominant height were both estimated at high accuracies for all local maxima filtering techniques and lidar point densities. The results were also comparable to the approach that employed regression analysis that related lidar-derived distributional metrics and field measurements. Estimated dominant height and SPHA, as well as age of trees, were used as independent variables in a function to estimate plot-level basal area. The basal area was then used to compute diameter of the tree with mean basal area, referred to as quadratic mean diameter at breast height (QDBH). Mean tree height and QDBH were used as independent variables in a standard equation to calculate mean tree volume, which was then scaled up to the plot-level. All estimates for the local maxima filtering approaches and lidar point densities returned negatively biased volume, when compared to field observations. This was due to the underestimation of SPHA, which was used as a conversion factor in scaling up from tree-level to plot-level. Volume estimates across lidar point densities exhibited similarities. This suggests that low lidar point densities (e.g., 1 point/m2) have potential for accurate volume estimation. It was concluded that multiple forest structural attributes can be assessed using lidar data only. The accuracy of height derivation meets the standards set by field inventories. The underestimation of SPHA may be comparable to other studies that applied different methods. However, improved estimation accuracy is needed in order to apply the approaches to commercial forestry scenarios. The significance of improving SPHA estimation extends to improved volume estimation. In addition, the potential improvement should also take into consideration the density of lidar points, as this will impact on the cost of acquisition. This research has taken a significant step towards determining if lidar data can be used as a stand-alone remote sensing data source for assessment of structural plantation parameters. Not only does such an approach seem viable, but the lower required point densities will help to reduce acquisition costs significantly. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2009.

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.