20 results for Bachelors

  • A survey of the jet noise problem

    Norrie, D. H. (1954)

    Bachelors thesis
    University of Canterbury Library

    A review is made of the available literature relating to the aerodynamic generation of noise from gaseous jets, with particular references to the physiological and physical aspects, both theoretical and practical. It is shown that noise generated by jet engines constitutes a serious problem and that thus will soon become a limiting factor or power and thrust of such engines. Jet engine noise and model jet noise can be broadly correlated, but the large number of parameters involved and the shortage of data limits the usefulness of such a correlation. In particular, the effect of turbulence has been neglected in much experimental work, although this is one of the most important parameters. The design and manufacture of apparatus to investigate the affect of the Mach number on jet noise is described although the experimental work has not yet been completed and is not included, but is to follow in a later report.

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  • Validation of a Redwood Sequoia Sempervirens (D. Don) Endl Butt Log Sawing Simulator

    Ashford, Sheridan (2013)

    Bachelors thesis
    University of Canterbury Library

    Redwood (Sequoia sempervirens (D. Don) Endl.) has been identified as a species with considerable potential for plantation forestry in New Zealand. Investment decisions in high value alternate species must be based on accurate wood quality and value predictions. There is an opportunity to extend non-destructive evaluation tools available to redwood growers, and to present the outputs of the growth model by log products and sawn timber. A redwood pruned buttlog sawing simulator has been developed however the simulator had not been tested with real data. Twelve redwood trees from Mangatu estate were selected for a sawing study; these logs were reconstructed and run through the sawing simulator. Computerised log processing was used to produce simulated pruned log sawing outturn from the redwood Buttlog Sawing Simulator, and results were compared to real results from a sawing study. The objective of the study was therefore to determine how well the simulator matched volume and grade out-turn from twelve logs. This study found the many inconsistencies between simulated data and real data; particularly related to log size. While this study was unsuccessful in validation of the redwood sawing simulator, it provides initial insight into the simulators strengths and short comings.

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  • The Impacts of Species, Physiological Age and Spacing on Tree Form and Branching

    Naylor, Sarah (2013)

    Bachelors thesis
    University of Canterbury Library

    This dissertation examined the impact of species, physiological age and spacing on tree form and branching at a Nelder experiment located near Rolleston, Canterbury. Two species were compared, Pinus radiata and Eucalyptus nitens, at a range of stockings from 271 stems/ha to 40,466 stems/ha. Within the P. radiata, two different physiological ages were compared. Stocking and species significantly affected (p-value <0.05) tree height, diameter at breast height (DBH), crown depth, branch mortality, branch angle, branch size and internode length. Only stocking was statistically significant for crown width, and height from the ground was also statistically significant for branch angle and branch mortality. DBH, crown width, crown depth, branch size and branch survival decreased with increasing stocking for both species. Branch angle and average internode length increased as stocking increased for both species, and branch angle and average internode length also increased as you moved away from the base of the tree. DBH, average internode length and branch size were significantly larger for P. radiata across all stockings, however branch mortality and branch angle were significantly larger for E. nitens. Physiological age was not statistically significant for any aspects of tree form or branching examined in this study.

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  • Evaluating the effects of initial stocking, physiological age and species on wood stiffness

    Watson, Liam (2013)

    Bachelors thesis
    University of Canterbury Library

    The influence of initial stocking and physiologically aged cuttings (taken from 1-year- old and 5-year-old parents) on corewood modulus of elasticity (MOE) in 6-year-old Pinus radiata D. Don was studied in a Nelder-design experiment in Rolleston, Canterbury. In the same experiment, the influence of initial stocking on MOE in 5-year- old Eucalyptus nitens was also investigated. The study incorporated 19 different stocking levels ranging from 207 to 40,446 stems/ha. Green dynamic modulus of elasticity was assessed in standing trees using the TreeTap stress-wave method over the lower part of the stem (0.3 – 1.9m) for 151 P. radiata trees and 115 E. nitens trees. The interaction between species and stocking significantly influenced MOE (P<0.001). MOE of P. radiata increased by 55% (or 3.9 GPa) between 271 and 40,466 stems/ha, and by 41% (or 2.2 GPa) between 271 and 4370 stems/ha. MOE of E. nitens was also influenced by stocking but the slope was significantly lower indicating that the effect of stocking was less pronounced than for P. radiata. Over the usual range of stockings for E. nitens there was an insignificant relationship between stocking and stiffness (P=0.335). Trees were also assessed for DBH, height, and stem slenderness (height/ DBH). None of these latter variables had a significant influence on MOE after the effects of stocking and species were accounted for. No effects of physiological age of cuttings were detected in this study. The findings of this study highlight the importance of stocking as a tool that forest managers can utilize to regulate corewood stiffness in P. radiata trees. These results also suggest that for E. nitens, where wood stiffness is a priority, forest managers could reduce establishment costs by planting at much lower initial stockings. This study also highlights the superior stiffness of E. nitens in direct comparison with P. radiata, with many trees in the experiment already exceeding stiffness thresholds for structural timber in New Zealand.

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  • Economic analysis of a target diameter harvesting system in radiata pine

    Perry, Christopher (2013)

    Bachelors thesis
    University of Canterbury Library

    Target diameter harvesting (TDH) is a forest management system in which all stems above a set minimum diameter are harvested on a periodic basis. There is evidence in the literature that TDH can achieve a rate of return on a similar scale to a clearfelling regime, with added benefits of regular cash flow from partial harvests, and preservation of non-timber values. Economic analysis was carried out on 12 years of TDH using permanent sample plot (PSP) data from Woodside Forest, a 30ha plantation of radiata pine (Pinus radiata). The Woodside Forest management regime has a target diameter of 60cm, and a harvest cycle of two years. Economic analysis considered the option to partial harvest or clearfell every two years, and compared the outcome of each option in terms of land expectation value (LEV). Comparisons are made between regimes with different numbers of partial harvests, assessing the effect of TDH on stand LEV. Results show that in three of four applicable stands, LEV reached a maximum at ages 30 – 32, (near the time when partial harvesting commenced), and reduced slowy with increased numbers of partial harvests. This shows there is a small opportunity cost associated with choosing TDH over a clearfell system. The effect of revenue from early partial harvesting operations on LEV was small as the majority of stand value is still in the standing crop. This limited the conclusions that can be drawn form this study due to the short time frame analyzed. The study was limited by a small dataset which did not accurately represent average stand values. Because of this, no attempt to quantify the value of the opportunity costs was made. Despite this, the results support the notion that TDH can achieve economic returns similar to clearfelling in radiata pine forests.

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  • The influence of weed control, clone, and stem dimensions on wood quality of 17 year old stems of Pinus radiata which has been grown on the Canterbury Plains

    Callaghan, Andree (2013)

    Bachelors thesis
    University of Canterbury Library

    This study determined whether variation in clone, weed control treatment, or stem dimensions, could have an impact upon outerwood stiffness in 17 year old Pinus radiata stems. An experiment located south west of the Dunsandel township in Canterbury, New Zealand, was used to collect measures of acoustic velocity (windward and downward sides) from each of the 278 trees. Diameter at breast height, tree height, and height to live crown were also recorded for each tree. Findings from this research were compared with previous research carried out when the trees were ages eight and eleven. Assuming a green density of 1,000 kg/m3, Young’s Modulus equation was used to convert acoustic velocity to wood stiffness, or, Modulus of Elasticity (MOE). The effect of wind direction upon mean wood stiffness was not significant (α = 0.05). Consequently, one measure of wood stiffness was calculated per tree. Mean stem slenderness and mean wood stiffness values were calculated by block, weed control treatment, and clone. Weed control treatments had a significant impact upon mean wood stiffness in comparison to the control treatment (0.03 m2 area of weed control). Significant differences did not exist between different levels of weed control, ie., 0.75 m2, 3.14 m2 and 9 m2 chemical spot spray area. Clonal variation and stem slenderness significantly affected mean wood stiffness measures. Stem slenderness appeared to be correlated with clonal variation (interaction between clone and slenderness was not significant), however, according to Dr. Euan Mason, this finding is not corroborated by findings from other research on the wood quality of clones in Canterbury (personal communication, September 16, 2013). An analysis of covariance (ANCOVA) determined that mean height to the live crown was not a significant predictor of wood stiffness. Comparison with earlier research showed no change in the ranking of wood stiffness values by clone or treatment.

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  • An investigation of the measurement accuracy and productivity of a Waratah HTH 625c Processor Head

    Saathof, David (2014)

    Bachelors thesis
    University of Canterbury Library

    Log processor heads have become increasingly used in New Zealand (NZ) forest harvesting operations to increase productivity and improve worker safety. Information regarding the measurement accuracy and productivity of new model processor heads is limited. As a result, log quality control (QC) is carried out on logs that have been merchandised by a processor head. This task can have a high risk for injury from man – machine interaction. A trend between studies was that older model Waratah’s did not have sufficient measurement accuracy to alleviate the requirement for log QC. In this study, a Waratah HTH 625c processor head operating in NZ was analysed for measurement accuracy and productivity. Measurement accuracy was considered by measuring logs for length, diameter and branch size. A comparison of two methods of processing was also considered to determine measurement accuracy, productivity and production efficiency for the way logs are delimbed and merchandised. Once gathered, the data was then analysed to identify significant effects, trends and relationships between variables. Length measurements were highly accurate but diameter measurements were under- estimated. It was also evident that although there was absolute accuracy, there was a high variability in measurements with underestimating and overestimating. Branch size was also found to have a significant impact in reducing length measurement accuracy and productivity. Single pass processing has significantly higher production efficiency than two pass processing, although single pass processing had a higher length error associated with it. The Waratah HTH 625c processor head has better measurement accuracy than older model Waratah’s. However, logs are still cut out-of-spec which will require a log QC to identify. As measurement technology is further improved in processor heads, and improvements to NZ’s plantation resource (improved form and smaller branching) are realised at harvest age, measurement accuracy and productivity of log processor heads will further improve.

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  • Forest Industry Employees: training, safety and retention

    Muir, Kate Rosemary (2014)

    Bachelors thesis
    University of Canterbury Library

    Forestry employees are the most valuable asset to forest operations. An analysis was completed to determine employee training status, how safe employees feel within their roles and identify major reasons of dissatisfaction. Through the development of job descriptions and person specifications, it was possible to identify the job requirements along with the personal attributes and qualifications required by employers, to ensure employees were capable of undertaking their role. There is an identifiable gap within the level of formal education among employees. Over half (55%) of the employees have lower qualifications than those required to have undertaken further forestry on-job training. A majority of employees’, particularly those in machine operator roles feel safe in their forestry operational roles. A small proportion of employees in breaker out, thin to waste and pruning roles feel unsafe. All employees surveyed except loader operators, felt only moderately safe in their role. The difficult environment associated with forestry was determined to be the major reason for dissatisfaction (52%) among employees, along pay and length of day. Paradoxically, the environment was also a major reason for satisfaction among those surveyed. By identifying the major reasons of dissatisfaction among forestry employees it is possible to improve job satisfaction and employee retention. Training forestry employees needs to be from a more practical aspect. This will lead to increase the number of employees that are trained for the roles they are undertaking, by ensuring they are equipped with adequate knowledge, and have the skill to work safely and to a high quality standard.

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  • The effect of plot co-registration error on the strength of regression between LiDAR canopy metrics and total standing volume in a Pinus radiata forest

    Slui, Benjamin Thomas (2014)

    Bachelors thesis
    University of Canterbury Library

    Background: The objective of this study was to verify the effect that plot locational errors, termed plot co-registration errors, have on the strength of regression between LiDAR canopy metrics and the measured total standing volume (TSV) of plots in a Pinus radiata forest. Methods: A 737 hectare plantation of mature Pinus radiata located in Northern Hawkes Bay was selected for the study. This forest had been measured in a pre-harvest inventory and had aerial LiDAR assessment. The location of plots was verified using a survey-grade GPS. Least square linear regression models were developed to predict TSV from LiDAR canopy metrics for a sample of 204 plots. The regression strength, accuracy and bias was compared for models developed using either the actual (verified) or the incorrect (intended) locations for these plots. The change to the LiDAR canopy metrics after the plot co-registration errors was also established. Results: The plot co-registration error in the sample ranged from 0.7 m to 70.3 m, with an average linear spatial error of 10.6 m. The plot co-registration errors substantially reduced the strength of regression between LiDAR canopy metrics and TSV, as the model developed from the actual plot locations had an R2 of 44%, while the model developed from the incorrect plot locations had an R2 of 19%. The greatest reductions in model strength occurred when there was less than a 60% overlap between the plots defined by correct and incorrect locations. Higher plot co-registration errors also caused significant changes to the height and density LiDAR canopy metrics that were used in the regression models. The lower percentile elevation LiDAR metrics were more sensitive to plot co- registration errors, compared to higher percentile metrics. Conclusion: Plot co-registration errors have a significant effect on the strength of regressions formed between TSV and LiDAR canopy metrics. This indicates that accurate measurements of plot locations are necessary to fully utilise LiDAR for inventory purposes in forests of Pinus radiata.

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  • The effects of clumped log distribution on line intersect sampling

    Tansey, Joshua (2014)

    Bachelors thesis
    University of Canterbury Library

    Line intersect sampling (LIS) is a method used for quantifying post-harvest waste. It is often used by forest managers to quantify merchantable volume remaining on the cutover so that compensation may be exacted under stumpage contracts. The theory has been extensively studied and will produce an accurate measure of harvest waste given the basic theoretical assumptions that: all logs are cylindrical, occur horizontally, are randomly orientated and randomly distributed. When these assumptions are violated, the method is not biased, although precision decreases substantially. A computer simulation was completed to determine whether or not the LIS method is appropriate, given a clumped distribution of logs produced by processing at central sites in cutover before using a forwarder to extract to the landing. The software ArcGIS with the application ModelBuilder was used to produce the LIS Model for running LIS assessments. It was determined through simulation that the conventional LIS method is not appropriate given these harvesting methods, as a level of bias was found in sampling determining that the LIS method underestimated true volume. T-tests confirmed the significance of this bias. LIS volume estimates were not precise, with the range of estimates ranging from 0 m3/ha to double the true volume. An increase in sampling length by a third was found to increase precision by only a small amount. Therefore, it was determine that increased sampling is not worthwhile as the costs associated with it do not justify the small increase in precision.

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  • Calculating the potential increase in Pinus radiate stem value through selection for higher stiffness

    Ferguson, George (2014)

    Bachelors thesis
    University of Canterbury Library

    New Zealand grown Pinus radiata is limited in its application for structural purposes by its stiffness deficiencies. This dissertation aims to estimate potential improvements in stem value through selection for improved stiffness. A new method to model and value volumes of structural wood grades within a stem was used to calculate these value improvements. Data for each stem from a stand in Kaingaroa Forest bred for improved wood quality was used to perform this analysis. This data was from a stand bred for improved wood quality and included information on the stiffness, density and width of each growth ring for each stem. The data was in the form of cores. Height and volume data was not recorded and therefore needed to be modelled. The volumes of MSG8, MSG11 and MSG13 wood were estimated by modelling the stem volume at the age when wood is produced that is stiff enough to qualify for each grade. The majority of stems had merchantable volumes between 1-2.5m3 with the largest stems containing 3.6m3. Average stiffness ranged between 5.2GPa and 11.3GPa with the stand average being 8.4GPa. There was no relationship between average stiffness and merchantable volume. Stem values were found to range between $60-$131/m3 with the stand average being $91/m3. The 10 most valuable stems had a total stem value ($318) twice that of the stand average ($157). The most valuable stem ($411) showed a 160% increase in stem value from the average. The increases in value/m3 were caused by large increases in the proportion of MSG11 and MSG13 wood held within the merchantable volume. These potential gains in stem value could help tree breeders assign an accurate economic weighting to stiffness improvements. Forest managers wanting to justify using a more expensive, improved stiffness seedlot may also find these results valuable.

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  • Edaphic zoning and species-site matching to assist re-vegetation of indigenous species at the Styx Mill Reserve

    Campbell, Thornton (2014)

    Bachelors thesis
    University of Canterbury Library

    The Styx Mill Reserve is located in Belfast, Christchurch and is managed by the Christchurch City Council. Who aim to re-establish indigenous vegetation to large proportions of the area. These efforts have been successful in some sections of the Reserve; but large areas of the Reserve remain in grass and other weeds. The purpose of this investigation was to evaluate the presence of 5 hypothesised edaphic1 zones in a 10 ha study area, with a future aim of matching establishment practices to these edaphic sites. Findings indicated that all zones have significantly different vegetation and soil characteristics. Consequentially methods of native re-vegetation must be different in each zone if successful re-establishment of native species is to occur. Based on confirmed edaphic zones and client input, a site matched management plan and species list for one zone was developed. This aimed to increase the health and survival rates of plantings. Site modification followed techniques used at sites with similar conditions that have had successes in establishing woody vegetation. The effect of hydrogel on heath and survival levels was also trialled. To assess species suitability, five species were selected based on their abilities to survive the site conditions. Due to a combination of frost damage and ungulate browse, only totara survived and demonstrated good health scores. The frost factor is difficult to mitigate, hence species affected severely by frost are not recommended. The browse issue is easier to mitigate and it is felt that the two species heavily browsed, but not frosted are likely to be suitable. This resulted in ribbonwood, totara and kōhūhū being recommended. The time period did not allow assessment of the hydrogel treatment. Insufficient trial numbers exist to continue trials assessing future growth and survival rates over a longer time scale.

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  • A comparative study of mechanized cable harvesting systems in New Zealand

    Nuske, Samuel Ryan (2014)

    Bachelors thesis
    University of Canterbury Library

    Productivity and safety concerns of traditional cable harvesting systems have been the key drivers for increasing levels of mechanisation in New Zealand. The use of grapples in cable yarding could eliminate the need for motor-manual tree fallers and breaker-outs in most situations. A comparative time study was carried out on two mechanised cable harvesting systems utilising grapple carriages in an attempt to better understand the benefits and limitations of each system in different harvest settings. These systems include the Mechanical system which involved a swing yarder operating a mechanical grapple carriage and the Motorised system, which used a tower yarder with a motorised grapple carriage. The Mechanical system took less time to accumulate felled trees but took longer to unhook trees on the landing than the Motorised system. The Mechanical system had a shorter cycle time (2.07 minutes) than the Motorised system (2.32 minutes) and extracted 1.3 tonnes more than the Motorised system per cycle. The Motorised system had shorter cycle times when in horizontal haul distances of less than 90 metres, but had the longest times when the distance exceeded this. Utilisation rates were similar between the two systems, although the main difference in delays between the two systems was the use of surgepiles on the landing by the Motorised system. Both systems were effective, although on average the Mechanical system was more productive, with a productivity of 45 t/SMH, compared to 40 t/SMH for the Motorised system. The Mechanical system was the most productive when extracting mechanically felled and pre-bunched or trees while the Motorised system was the most productive when extracting motor-manually felled trees. Pre-bunching with an excavator was a more cost effective method than handing stems directly to the grapple carriage. Further research of the Mechanical system under more adverse conditions would allow a better overall comparison.

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  • Vegetation classification of an area on coal measures, Buller, New Zealand.

    Newell, Claire (1990)

    Bachelors thesis
    University of Canterbury Library

    The plant communites of a coastal hillslope, Buller, were classified on the basis of floristic presence/absence of 138 species. Six forest communites were identified from 75 descriptions on a forest remnant on tertiary Brunner coal measure parent material and 17 from a comparative area on upper cambrian Greenland greywacke. Community distribution was not affected by differences in underlying parent material. Forest community distribution related to elevational gradients, landform type, slope and aspect. Compositional changes were gradual with the most distinctive separation between steep, low altitude hard beech (Nothofagus truncata) dominated communities and low sloping montane to subalpine mountain beech (Nothofagus solandri var cliffortioides) dominated groups. This study encompasses an area of much broader elevational and floristic range, under higher rainfall and extremely acidic soils, than previous coal measure vegetation classification studies have documented. Lowland communities in this study differed from those previously identified in the Ngakawau Ecological District. Preservation of this diverse, complex coastal hillslope forest system is recommended.

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  • The Effect of Landing Size on Operational Delays for New Zealand Harvest Operations

    Jones, Blake (2013)

    Bachelors thesis
    University of Canterbury Library

    Landings are an integral part of New Zealand Harvest operations where extracted trees are processed into logs and loaded out onto trucks. Forest owners need to balance the cost and environmental considerations when designing and constructing landings, with the productivity and safety of the harvesting crew that will use the landing. The objective of this study is to gain a greater understanding of landing size and how they affect forest harvest operations. This study investigates the relationship between landing size and processing delays. A time study was carried out for ten harvest operations predominantly in the lower North Island. The time study recorded all delays on the processing task of measuring and cutting stems into logs. The delays were then categorised so that only processing delays that are influenced by the size of the landing remained. These processing delays were then expressed per m³ and used as the response variable in regression analysis to test their correlation against landing size and a range of other predictor variables. A very strong, linear relationship between processing delays per m3 and actual landing size was found. This indicates that harvest operations on smaller landings exhibited higher delays per m3 than those on larger landings. Loading of the deck was the most significant processing delay; this is a direct result of not having enough room for surge piles as delimbing was not able to be carried out during loader downtime. The significance of the relationships developed in this study can help forest owners realise the implications of building landings that are too small for the intended purpose. Not only will small landings affect productivity, but have the potential to financially affect the forest owner also.

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  • Paleoseismic analysis of the Springfield Fault, Central Canterbury

    Evans, Stewart Thomas (2000)

    Bachelors thesis
    University of Canterbury Library

    The Springfield Fault is a northeast striking thrust fault bisecting the Russell Range at the northern end of the Malvern Hills near Springfield. The trace of the fault is best expressed by offset river terraces, as it cuts across the flood plane of the Hawkins River in the Upper Hawkins Basin. The Russell Range is composed chiefly of the basement Triassic rocks of the Torlesse terrane with Cretaceous to Cenozoic rocks occurring in a fault bounded slice and around the hinge of the hanging wall anticline of the fault. Quaternary glacial sediments occur on the plains adjacent to the Russell Range with Holocene deposits occurring in the Upper Hawkins Basin. Folding in the highly sheared basement is along NW-SE trending fold axes. The current direction of principal shortening was determined from slickenside data to be NW-SE to NE-SW. Geomorphology of the area in the Upper Hawkins Basin provided a chronology of the activity on the Springfield Fault. Offset of terrace surfaces provide evidence for the number of fault ruptures, which is at least two. An attempt to date the age of fault and river terrace scarps was made using their morphology and a diffusion model of scarp degradation. Analysis requires the diffusivity rate operating on a scarp to be known to produce an absolute age for the scarp. Only one of the scarps analyzed, a river terrace scarp produced a result. This was poorly constrained at 1000-7500 years old.

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  • Invasion by maritime pine in Abel Tasman National Park

    Sanson, L. V. (1978)

    Bachelors thesis
    University of Canterbury Library

    Maritime Pine is one of two species of exotic conifers present in Abel Tasman National Park, in significant numbers. The species was first planted at Bark Bay, (ca.1900) and since then has established itself particularly well, throughout many of the southern coastal areas of the Park. The pines characteristic ecological features make it especially well adapted to colonise many of the infertile and harsh sites that exist in proximity to the Park's coastline and give it a distinct competitive advantage over the indigenous flora of the area. Spread has generally been strongest in a southerly direction, away from Bark Bay, presumably influenced by prevailing winds in addition to suitable sites for colonisation. The rate of spread of the pine was calculated as 9.1 metres/year, at Bark Bay, away from the assumed initial seed source. It is important to note though, that this rate is considerably increased by the pine's ability to form outliers of pine, significant distances away from the original seed source. The outliers were generally found to be the result of strong winds (greater than Force 6) capable of carrying seed considerable distances, on to sites suitable for colonisation by maritime pin. Consequently this serves to increase the distribution of maritime pine within the Park. This pattern of long-range dispersal has only occurred since ca. 1940 and has only become increasingly prevalent in recent years. At present then, the pine occurs along some 9.2 kilometres of the Park's coastline. The pine appears to be type specific in its invasion characteristics with low Leptospermum shrubland vegetation types being the most susceptible to invasion. The pine will not usually establish where there is a closed canopy (i.e. Podocarp/Hardwood/Beech vegetation types). Obviously the rate of spread is increasing at an exponential rate as the pine becomes more widespread in its distribution throughout the Park. For this reason a programme of control is recommended, aimed at confining the species to the Bark Bay area, where it initially originated from.

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  • What causes natural durability in Eucalyptus bosistoana timber?

    Van Lierde, Julot (2013)

    Bachelors thesis
    University of Canterbury Library

    This study investigated the natural durability of 8 and 60 year old Eucalyptus bosistoana (coast grey box). The sample’s heartwood compounds were extracted with an optimised extraction process and then incorporated into agar. Trametes versicolor (white rot) and Gloeophyllum trabeum (brown rot) fungi were grown upon these agars and their growth rate was used to assess the fungicidal abilities of the extracts. The extraction method of cell wall compounds was optimised. An Accelerated Solvent Extraction system (ASE) was used with the following settings: • 2 cycles per sample • 70°C extraction temperature • 50% rinse • 5 minute static time Ethanol was found to extract the compounds of the highest fungicidal activity. Ethanol was found to extract similar amounts to water (~13% of dry weight for a 60 year old sample), however analysis of both water and ethanol extracts with a FTIR spectrometer, found that they were of different chemical composition. A difference in fungicidal activity of extracts was found between the 8 year old and 60 year old samples. There was a large difference in the percentage of extracts present between the samples as well as the type of compounds present, shown by FTIR.

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  • Above and Below Ground Assessment of Pinus Radiata

    McQuillan, Shane (2013)

    Bachelors thesis
    University of Canterbury Library

    A comparison of above ground forest metrics with below ground soil CO₂ respiration was carried out in an attempt to reveal if any correlations exist. Above ground measurements of 2720 clonally propagated trees were taken assessing the silvicultural treatments of stocking, herbicide and fertiliser. These were compared to 480 below ground soil CO₂ respiration measurements. Using measurements of mean height, mean dbh and basal area the data was analysed and returned significant results for mean dbh and the interactions of herbicide and clones, and stocking and herbicide. Mean height returned a significant result for the interaction of stocking and herbicide. Below ground measurements showed an interaction between ripping and stocking; however these results were not ratified by the above ground results. Overall the results were encouraging and should aid in future experiments that seek to understand what effect above ground treatments have on below ground CO₂ activity.

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  • Irradiation as an alternative phytosanitary treatment for Arhopalus ferus and Hylurgus ligniperda

    van Haandel, Andre (2014)

    Bachelors thesis
    University of Canterbury Library

    Wood products all require treatment to mitigate phytosanitary risk prior to exportation. The most common phytosanitary treatment applied to Pinus radiata logs is Methyl Bromide (MeBr). The Environmental Protection Agency (EPA) in 2010 stated that MeBr must not be release into the atmosphere past 2020. This poses a problem for New Zealand log exports. Radiation has been identified as a possible alternative phytosanitary treatment for export wood products. This study aimed to quantify the effective dose of radiation necessary to sterilise two forest pest species; Arhopalus ferus and Hylurgus ligniperda. These species are representative of two different types of forestry pests; bark beetles (H. ligniperda) and wood borers (A. ferus). All applicable life stages for both species were tested. Arhopalus ferus adults were the most susceptible life stage identified with an LD99 of 30.2Gy ± 13.5 Gy (95% confidence interval). Arhopalus ferus eggs were less susceptible with a LD99 of 750Gy ± 776Gy observed; however there is low confidence in this result due to a methodological issue in one treatment replicate. Hylurgus ligniperda eggs were observed to be less susceptible than A. ferus eggs with a LD99 of 289Gy ± 92Gy. Results for the other life stages were inconclusive due to poor control survival, however the information gained was used to develop improved methods for further experimentation, which is on-going and showing positive results so far. The results of this experiment have indicated that radiation can be an effective method of sterilising forestry pests. To date radiation has not been used as phytosanitary risk mitigation for wood exports; however it is widely used for risk mitigation in agricultural products. Currently there remains a large amount of unknown information regarding, the effectiveness for irradiation of logs, the effective dose require for sterilisation of the most tolerant forestry pest and public acceptability of irradiation as a phytosanitary treatment. These knowledge gaps and an economic assessment must be completed before irradiation can be used as a phytosanitary risk mitigation technique for forestry products.

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