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The intermontane Mackenzie Basin is located within the central South Island of New Zealand. The glacial basin contains three glacial lakes which are used for hydroelectric power generation via a canal system that links the lakes. The basin is an area of climate extremes, low rainfall, high summer temperatures, and snowy winters. The area is predominantly used for pastoral farming, however farming practices are changing and, combined with an increasing population, there is a need to define the groundwater resources to enable sustainable resource management. Little is currently known about the hydrogeological system within the Mackenzie Basin, and what is known is from investigations carried out during the construction of the canal system from 1935 to 1985. There are four glacial formations that overlie Tertiary sequences and Torlesse bedrock. However, due to the glacial processes that have been ongoing over at least the last 300 ka, determining the occurrence and extent of groundwater within the outwash gravels is difficult. It is suggested that the permeability of the formations decreases with depth, therefore horizontal and vertical hydraulic conductivity decrease with depth. A shallow groundwater table is present within the Post Glacial Alluvial Gravels which is recharged directly from fast flowing streams and rivers as well as rainfall. It appears that this shallow system moves rapidly through the system and it is unlikely that the water infiltrates downwards to recharge the deeper groundwater system. It is thought that a deep groundwater system flows preferentially through the Mt John Outwash Gravels, being the second youngest glacial formation. Water chemistry and age dating tracer analysis indicate that the deeper groundwater is over 80 years old and that the groundwater system is recharging slowly. The shallow groundwater in the Post Glacial Alluvial Gravels and within the major fans to the east of the basin is 10 to 20 years in age. Baseline data such as water chemistry, groundwater levels, and surface water gaugings have been collected which can be used for future investigations. More data needs to be collected to create a long term record to further define the hydrogeological system and to determine the best way to manage the resource for long term sustainable use in the future.

The intermontane Mackenzie Basin is located within the central South Island of New Zealand. The glacial basin contains three glacial lakes which are used for hydroelectric power generation via a canal system that links the lakes. The basin is an area of climate extremes, low rainfall, high summer temperatures, and snowy winters. The area is predominantly used for pastoral farming, however farming practices are changing and, combined with an increasing population, there is a need to define the groundwater resources to enable sustainable resource management. Little is currently known about the hydrogeological system within the Mackenzie Basin, and what is known is from investigations carried out during the construction of the canal system from 1935 to 1985. There are four glacial formations that overlie Tertiary sequences and Torlesse bedrock. However, due to the glacial processes that have been ongoing over at least the last 300 ka, determining the occurrence and extent of groundwater within the outwash gravels is difficult. It is suggested that the permeability of the formations decreases with depth, therefore horizontal and vertical hydraulic conductivity decrease with depth. A shallow groundwater table is present within the Post Glacial Alluvial Gravels which is recharged directly from fast flowing streams and rivers as well as rainfall. It appears that this shallow system moves rapidly through the system and it is unlikely that the water infiltrates downwards to recharge the deeper groundwater system. It is thought that a deep groundwater system flows preferentially through the Mt John Outwash Gravels, being the second youngest glacial formation. Water chemistry and age dating tracer analysis indicate that the deeper groundwater is over 80 years old and that the groundwater system is recharging slowly. The shallow groundwater in the Post Glacial Alluvial Gravels and within the major fans to the east of the basin is 10 to 20 years in age. Baseline data such as water chemistry, groundwater levels, and surface water gaugings have been collected which can be used for future investigations. More data needs to be collected to create a long term record to further define the hydrogeological system and to determine the best way to manage the resource for long term sustainable use in the future.

Palynological and maturation data are combined to reconstruct the burial and thermal history of three oil wells in the Beaufort-Mackenzie Basin. From south to north, the three wells are Netserk F-40, Tarsuit A-25, and Orviiruk 0-03. Each well was examined palynologically and zoned based on species ranges of pollen, spores, fungi, and algal cysts. Using local extinction events of zonally diagnostic species to define the tops of intervals, seven informal palynozones are presented: Laevigatosporites (Pleistocene); ChenopodipoJlis (Pliocene to early Pleistocene); Ericipites (middle to late Miocene); Selenopemphix-1 (middle to late Oligocene); Integricorpus (early Oligocene); Araliaceoipollenites (late Eocene to early Oligocene); Pistillipollenites (middle Eocene). Correlations within the basin indicate that the proposed zonation may be useful for local correlations. Correlations outside the basin indicate that the palynological assemblages from the Beaufort-Mackenzie Basin may not be as isolated and endemic as first thought. A high recovery of algal cysts is attributed to less harsh maceration techniques, and confirms a significant population of cysts from a region in which they were formerly believed to be relatively scarce. The palynology does not exhibit an increase in marine influence with decreasing proximity to the basin margin. Instead it shows a consistent, strong terrestrial influence throughout each well. The large terrestrial discharge from the Mackenzie River is interpreted to have masked the effect of basin proximity on the palynology of the area. The study wells are dominated by terrestrial Type III organic matter. Recycled and terrestrial inert material often make up over 95 % of the residues. These results support a terrestrial source for the offshore oils in the Beaufort -Mackenzie Basin. There is a small but consistent presence of potential oil-generating material throughout each well (amorphous and liptinite). The liptinite is largely composed of pollen grains, spores, and leaf cuticle. Algal cysts are present but less abundant. If the observed amounts of amorphous and liptinite material continue to some depth, where the required level of thermal maturation might be reached, these sediments could act as source rocks for hydrocarbons. The rare occurrence of resinite in the study wells questions the resinite source theory for the hydrocarbons in the basin The sediments in each of the three study wells are immature to total depth, and could not be the source of Tertiary oils in the Beaufort - Mackenzie Basin. The levels of maturity in the wells, and the low maturation gradient calculated for Netserk F-40 (0.07 Ro/km), suggest that thermal maturation will only be achieved at much greater depths. This is most likely due to rapid sedimentation rates in the basin during the Tertiary. By combining the zonations from Chapter 3 with the maturation data from Chapter 4, the burial and thermal history of each study well is reconstructed. Using a modified version of Lopatin's method, paleo-geothermal gradients are calculated for each well. In each case, the gradient that best accountes for the measured maturities is 15 °C/km. The calculated gradient is approximately 1/2 to 1/3 of the present geothermal gradients for the wells. The gradient is in agreement with those previously calculated from similar basins, and is considered responsible for the failure of any of the study wells to encounter effective source rocks. Source rocks of Tertiary oils in the Beaufort-Mackenzie Basin will only exist at greater depths than those encountered in this study. Prospective targets may therefore be located adjacent to sites where vertical migration of hydrocarbons is likely, such as steeply-dipping faults. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

Honeybees are used as a major agricultural input around the world and their pollination services have been valued at US$14.6 billion to the United States alone. Dramatic declines in honeybee populations around the globe, however, questioned the sustainability of this reliance on a single pollinator species. In this study, I investigated the response of wild pollinator communities to declining honeybee density and changing land use intensity to determine the potential of wild pollinators to compensate for honeybee loss in an increasingly human-modified environment. I generated a gradient of declining honeybee density using increasing distances from commercial bee hives, and conducted flower observations on experimentally-grown plants across this gradient. I investigate how declining honeybee densities and intensifying land use combine to influence the composition of the pollinator community as a whole, then go on to explore individual trends in the most common pollinator species. I then analyze how this impacts the transport of viable pollen by the pollinator community and determine how these changes alter seed set in several common plant species. I then change my focus away from the composition of the pollinator community, and instead investigate how declining honeybee densities and land-use intensification influence the structuring of interactions between plants and pollinators within the community. I identify the pollen species carried by pollinators, and use this to construct a network of pollination interactions. I then use this network to analyze how changes in the way species interact influences the pollination services delivered by the pollinator community to different plant groups (weeds, native plants, and crop species). My findings show that honeybee declines may have a large impact on community structure and interactions within pollination systems. I observed a significant shift in the wild pollinator community composition as honeybee densities declined, from a generally bee/hoverfly dominated community to one more dominated by large flies. This was associated with a significant decline in the total pollen load transported by the community, indicating that pollination services may suffer in the absence of honeybees. As honeybee densities declined, however, I also observed a shift toward greater specialisation of pollinators on abundant resources, increased pollinator constancy, and a higher viability rate of the pollen transported. These findings show that although the total amount of pollen transported by the community declined as honeybee densities decreased, the probability of this pollen transport resulting in effective pollination likely increased. Thus, I observed no decrease in seed set with honeybee declines in any of the three plant species tested, and one of these even showed a significant increase. Finally, I also demonstrated that this change differentially affected different plant types, and that the extent of changes to each plant species differed between land-use types. This reflected changes in the relative abundance of pollen types in different land uses, with greater specialisation in the absence of honeybees disproportionately benefiting common species. These findings have strong implications for several contemporary issues in pollination biology, both locally within New Zealand and on a global scale. These are discussed in the following sections. Finally, I conclude by discussing the implications of this research on several contemporary issues in pollination biology, namely the ability for wild pollinators to compensate for honeybee declines, the impact of honeybees on natural new Zealand ecosystems, the contribution of honeybees to invasive weed pollination and finally the management of surrounding land use types to maximize the effectiveness of wild pollinators.