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Item Spatial and environmental patterns of rare lotic macroinvertebrate diversity : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Ecology at Massey University, Manawatū, Palmerston North, New Zealand(Massey University, 2021) Rados, Dimitrios A.Stream macroinvertebrate communities comprise a few common taxa and many rare ones. Small populations of rare taxa can be more vulnerable to environmental change than those of common taxa. However, they are often discarded from community analyses on the grounds that they complicate data interpretation. The aim of this thesis was to evaluate the effect of rare taxa on assessing ecosystem health and on interpreting biodiversity patterns based on lotic macroinvertebrate communities. I assessed the effect of multiple types of rare taxa exclusion on biomonitoring, using macroinvertebrate data collected for the National River Water Quality Network of Aotearoa New Zealand. I compared the effect of different sampling methods on biodiversity patterns of rare taxa in pristine streams in the Tongariro National Park and determined the local environmental variables most strongly linked with common and rare taxa. Finally, I evaluated the effect dispersal processes and local environment have on structuring the common and rare components of lotic communities, considering the position within the stream network and the dispersal mode of the invertebrates. Exclusion of rare taxa led to significant misclassifications of ecological quality by biomonitoring tools that use presence-absence data, such as the Macroinvertebrate Community Index, and often masked their relationship with nutrient stressors. Different sampling methods collected clearly differentiated rare components of lotic assemblages, depending on the habitat sampled (riffles, non-riffles) and the life-stage of the invertebrates (benthic larvae, flying adults). A comprehensive species inventory can be compiled by combining methods, with benthic samples as the basis. Biodiversity metrics of the common and rare components of macroinvertebrate communities were related to similar environmental variables. While the structure of the two components was related to different variables, in combination they revealed a greater number of relationships with the environment. Rare taxa assemblages were not structured clearly by either local environment or dispersal processes, however their inclusion was necessary to demonstrate that the complete communities were determined by the local environment. Overall, I did not find any reason to exclude rare taxa from lotic macroinvertebrate studies, but rather found they can facilitate community analyses. Given the increasing threats on lotic macroinvertebrate biodiversity, it is also crucial to include them in such studies, hopefully so we can prevent their complete extinction.Item Understanding magmatic processes and their timescales beneath the Tongariro Volcanic Centre through microanalytical investigations of the tephra record : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Earth Sciences at Massey University, (Manawatū Campus), Palmerston North, New Zealand(Massey University, 2020) Lormand, CharlineThe Tongariro Volcanic Centre (TgVC) is a complex volcanic system located at the southern end of the Taupo Volcanic Zone in New Zealand, and has produced historical explosive eruptions of different eruptive styles. Its three ski fields and its iconic Tongariro Alpine Crossing attract more than 130,000 visitors annually. The last eruption occurred in 2012 on the northern flank of Tongariro, at the Te Maari vent. Due to the lack of precursory activity, this eruption could have turned into a tragedy if it had happened during day time. Previous studies have focused on the TgVC phenocrysts, which do not provide insights into shallow magmatic processes, essential to mitigate the resulting volcanic hazards. To understand magma ascent processes and their associated timescales, the textures and compositions of the micrometre-sized crystal cargo (i.e. microlites and micro-phenocrysts) carried during explosive eruptions are investigated, along with their conditions of crystallisation [i.e. P-T-X(H₂O)], which are constrained using hygrothermobarometry and MELTS modelling. Glass shards from five tephra formations spanning from c. 12 ka BP to 1996 AD, associated with explosive eruptions ranging from Strombolian to Plinian in style, are studied here. High resolution images and chemical maps of the tephras and the crystals are acquired using scanning electron microscopy (SEM) and secondary ion mass spectrometry. The variety of disequilibrium textures and compositions found in the micro-phenocrysts (< 100 μm) indicates multiple events of magma mixing, magma recharge, pressure fluctuations, and suggests an antecrystic origin. Crystal size distribution (CSD) of 60,000 microlites (< 30 μm) of plagioclase and pyroxene are generated from back-scattered-electron (BSE) images using a semi-automatic method developed here to undertake this study, employing the Weka Trainable Segmentation plugin to ImageJ. Combined with a well-constrained growth rate, crystallisation times are derived and indicate that microlites crystallised 2 to 4 days before the eruption, regardless of the eruption style. Microlite crystallisation occurred between mid-crustal depths and the surface (average of c. 4 km), at unusually high temperature for arc magmas of intermediate composition (average of 1076 °C), and at low water contents (average of 0.4 wt%). Considering the inferred depths and the crystallisation times of 2 to 4 days, ascent rates of only up to 9 cm s⁻¹ prior to shallow water exsolution are calculated. Vent exit velocities are not exceeding 27 m s⁻¹ after complete water exsolution, too slow to feed explosive eruptions characterised by supersonic exit velocities. This research proposes a new conceptual model for the magmatic plumbing system beneath TgVC, where the microlitic crystal cargos result from multiple intrusions of aphyric melts through dykes, which most of the time stall and evolve at depth as deep as the mid-crust. Eventually, a magma injection percolates through previous intrusions and entrains crystals of differing textures and histories. Dykes feeding volcanism funnel into a narrow cylinder towards the surface, allowing acceleration and triggering explosive eruptions. Therefore, the conduit geometry at TgVC is a key controlling factor on the explosivity, with narrower conduits resulting in more explosive eruptions, suggesting that volatile-poor magmas can still trigger explosive eruptions. This study supports that vertical foliation of the igneous upper crust is consistent with dyking and thus may be more common than typically acknowledged.Item Analyzing seismic signals to understand volcanic mass flow emplacement : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Earth Sciences at Massey University, Palmerston North, Manawatu, Aotearoa New Zealand(Massey University, 2017) Walsh, Braden Michael LarsonNatural hazards are one of the greatest threats to life, industry, and infrastructure. It has been estimated that around a half billion people worldwide are in direct proximity to the danger of volcanic hazards. For volcanic mass flows, such as pyroclastic density currents and lahars, extreme runout distances are common. The close proximity of large population centers to volcanoes requires the implementation of early warning and realOtime monitoring systems. A large portion of the progress towards realOtime monitoring is through the use of geophysical instrumentation and techniques. This research looks into emerging geophysical methods and tries to better constrain and apply them for volcanic purposes. Specifically, multiple types of amplitude source location techniques are described and used for locating and estimating the dynamics of volcanic mass flows and eruptions. Other methods, such as semblance and back projection, are also employed. Applying the active seismic source method to a lahar that occurred on October 13th 2012 at Te Maari, New Zealand, locations and estimations of lahar energy were calculated in an increased noise environment. Additionally, the first ever calibration of the amplitude source location (ASL) method was conducted using active seismic sources. The calibration proved to decrease true error distances by over 50%. More calibration on the ASL method was accomplished by using all three components of the broadband seismometer. Initial results showed that using all three components reduced extreme errors and increase the overall precision of the locations. Finally, multiple geophysical methods (ASL, semblance, back projection, waveform migration, acoustic-seismic ratios) were used to show that a combination of instrumentation could produce more reliable results. This research has filled gaps in the preexisting knowledge for hazards. With these results, more effective hazard warnings can be produced, and systems for real time estimations of locations and dynamics of volcanic events could be developed.Item The impact of honey bees on montane ecosystems within Tongariro National Park : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Ecology at Massey University(Massey University, 1996) Murphy, ClaireA study of the effects of honey bees on montane ecosystems was conducted during the summers of 1993/1994 and 1994/1995 at Tongariro National Park. Three possible effects of the introduced honey bee were examined. The primary aims of the study were to identity areas with and without honey bees and to identify differences in the pollination success of a weed species, heather (Calluna vugaris) and a native species, the New Zealand flax (Phormium tenax) under different pollinator regimes, and to examine differences in the composition of native pollinator communities in these different bee areas. The impact of honey bees on the reproductive success of heather, an important weed species in Tongariro National Park was examined over two flowering seasons. Insect visitation rates on heather flowers were low at each of the four study sites. Bagging plants to exclude insect flower visitors had little effect on female fitness. The potential of other pollen vectors, wind and thrips, as pollinators of heather was also examined. Both were determined to have a negative effect on several measures of female success, including pollen deposition, pollen tube formation, and pollination levels. However it appears that none of the pollen vectors (honey bees, wind or thrips) significantly effect the overall fitness of heather in terms of the viable seed produced. The second part of the study examined the impact of honey bees on the pollination systems of a native plant species. Flax is thought to be predominantly bird pollinated, however, the floral resources are also utilised by a variety of native and introduced insect species. At some sites birds were either not present or rarely used the flowers. Seed set in flax was highest in heavily bird pollinated sites. The results also suggest, however, that flax has a flexible pollinating system that enables it to maintain a range of fruit and seed set levels under the different pollintor regimes. The abundance and diversity of insect flower visitors on manuka and Hebe stricta, two common subalpine shrubs, was highly variable between sites, and between observation periods. Some of this variation may be ascribed to differences in the weather or to altitude. However, I have shown that the abundance and diversity of diptera appears to be strongly influenced by levels of honey bee activity. This indicates that honey bees do play a role in determining the structure of pollinator communities and may be displacing a significant component of the native pollinating fauna.Item Island biogeography : a study of habitat islands of mountain beech forest (Nothofagus solandri, var. cliffortioides) in Tongariro National Park : a thesis presented in partial fulfilment of the requirement for the degree of Master of Science in Zoology at Massey University(Massey University, 1982) Seden, MoyraMacArthur and Wilson's (1967) model for island biogeography is examined, particularly with regard to the proposed species-area relationship. The first chapter includes a consideration of the theoretical background. Nine habitat islands and corresponding mainland regions of similar area were selected. All the sites possess a canopy of mountain beech trees, (Nothofagus solandri var. cliffortioides), and are located in the western segment of Tongariro National Park. Plants and litter animals were sampled from within these sites to determine the possible relationship between species and area. Forest plant species numbers as well as proportions, assessed using a modification of the Point-centred quarter method, revealed a statistically significant species-area relationship. Litter Crustacea collected in one thousandth of a square metre core samples, and removed from cores by wet extraction, show a gradation in habitat preference, hence a species-area relationship cannot be determined. A wide range of animals collected in pitfall traps appear also not to produce a significant species-area relationship. Possible reasons for the obscurity of such a relationship are considered. An overall assessment of the information gathered in the light of island biogeographic theory is presented, and some more recent thought on the causal explanations for the species-area relationship are discussed.Item Palaeoecology by palynology : a palaeoecological study of the vegetation of the Tongariro Volcanic Centre, New Zealand, immediately prior to the c. 232 AD Taupo eruption : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Plant Biology at Massey University(Massey University, 2001) Banks, Natalie JaneThe usual source of pollen for analysis has been from within deposits of peat from lakes, bogs and mires. Soils have not generally been considered a potentially useful pollen source. Under some circumstances, however, (such as volcanic eruptions) a soil may be buried so rapidly that the pollen it contains will be more or less completely preserved in the resulting palaeosol. Studies of such volcanically buried palaeosol pollen have been made overseas. The last eruption from the Taupo Volcanic Centre occurred approximately 1800 years ago. The culminating phase of the eruption ejected ca 30 cubic kilometres of ignimbrite as a very hot and fluid pyroclastic flow which covered an area with a radius of 70-90 km centred on Lake Taupo. This deposit is known as the Taupo Tephra. The purpose of the present investigation was to examine peats and palaeosols directly beneath the Taupo Tephra from a variety of sites within the Tongariro area and to analyse any pollen preserved. Samples were taken from a total of 42 sites at various altitudes and distances from the eruptive source, and pollen extracted. Each sample taken, therefore, was from a buried soil or peat directly below the Taupo Tephra. The pollen contained within these samples and contains pollen deposited immediately prior to the eruption. An initial qualitative investigation indicated that the ignimbrite acts as an effective filter in preventing any contemporary pollen and spores from percolating through into underlying layers. The preservation of pollen was reasonably good at most sites allowing some conclusions to be drawn as to the structure and composition of the pre-eruption forests of the Tongariro area. Beech forest was widespread throughout, especially at higher altitudes, although mixed conifer associations were also evident, particularly in the west. At those sites where pollen preservation was poor, some alternative conclusions can be drawn about preservation environments within palaeosols. The pH value is particularly important, and pollen and spores are not well preserved when the soil pH value is in excess of 6.0. The possibility of differential preservation within the New Zealand flora is also examined.Item Invasion of woody species into weed infested areas : a thesis presented in partial fulfillment of the requirements for the degree of Masters of Science in Ecology at Massey University(Massey University, 2000) Trass, Amy PatriciaWhen studying plant dynamics and succession, it is important to determine potential limiting factors affecting recruitment (Crawley 1990). The purpose of this study was to investigate factors affecting the establishment and survival of woody species in weed infested areas around the central volcanic plateau. This was achieved by first describing these communities, and quantifying the number of native seedlings and saplings found in both forested and non-forested (weedy) areas. Seed input was measured with seed traps, and factors affecting recruitment of seedlings were investigated by manipulative field experiments. Although some native woody species were dispersed into weedy areas, both seed and seedling densities of most species declined rapidly with increasing distance from the forest margin. Sowing seeds at densities equivalent to 625 per m significantly increased seedling establishment of Griselinia littoralis and Coprosma 'taylorii' but not Pittosporum tenuifolium var. colensoi. Removal of exotic grasses (clearing treatment) that dominated in non-forest areas resulted in much greater establishment of all woody seedlings, including introduced broom (Cytisus scoparius) and several native species that had dispersed naturally. Most species also showed greater establishment in plots that were caged to prevent predation. However, the effects of clearing and caging treatments on survival of seedlings were not as apparent as they were for establishment. In addition, experimental clearing increased the growth of transplanted G. littoralis seedlings. Overall, most native species had much lower seedling establishment and survival in weedy areas compared with native forest. This is explained by a combination of both seed and microsite limitation in weedy areas. In another experiment designed to test the effects of bird consumption on seed germination, bird dispersers increased germination percentages of native species by removing fruits from seeds. All species examined (G. littoralis, Coprosma robusta, Pseudopanax crassifolius, and P. tenuifolium var. colensoi) showed very low germination of seeds within fruit, and much greater germination of seeds that were cleaned either by passage through birds or by hand. For C. robusta, G. littoralis, and P. tenuifolium var. colensoi, passage through birds also significantly increased germination of seeds compared with those cleaned by hand. The rate of germination was less affected by different treatments than the absolute percentage germinating, but was generally faster in bird-voided compared to hand-cleaned seed. Seeds in both of these latter treatments germinated considerably faster than seeds within fruit. Invasion of native woody plants in weedy areas appears to be constrained by a combination of low rates of seed dispersal for most species, and low probabilities of seedling establishment and survival in areas without disturbance. The most likely future scenario for the majority of weedy areas studied is continued dominance of exotic species in the short term, with slow succession to native shrubland as well-dispersed, frost-resistant native species such as manuka (Leptospermum scoparium) establish after disturbance. Management options are discussed with the aim of accelerating the rate of succession in weedy areas to native forest.Item Mediating the alpine archiscape : design and publicity for New Zealand's Tongariro National Park 1928-1984 : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Sociology at Massey University, Palmerston North, New Zealand(Massey University, 2013) Naismith, Jacqueline JuneThis thesis explores tourism publicity representing New Zealand’s Tongariro National Park and the Chateau hotel in the twentieth century, focusing specifically on how leaflets and brochures publicising the park worked as designed agents in the process of subjectivation. The thesis investigates how the documents’ representation of social actors in tourism landscapes rhetorically configures particular kinds of subjectivities. The objective of these investigations is to build and demonstrate a theory of ‘emplacement’ as a specific kind of subjectivation in tourism representations. This emplacement theory holds that subjects and places are co-constituted, such that the subject recognises itself in relation to the archiscape (defined as the built and natural elements of the place environment). The thesis uses this theory to analyse the historical specificity of emplacement. Publicity leaflets and brochures produced between 1929 and 1984 are selected as data for the case study. Emplacement processes in the brochures are investigated using the methods of critical semiotic and discourse analysis. Analysis has shown the rhetorical significance of luxury, and therefore of class and gender, for emplacement in the park. It has also shown how this emplacement has shifted over time. Four distinct historical moments are identified. In the late 1920s the park was constructed as a national recreation ground in which the absence of luxury is expressed as a spartan frugality. In the 1930s the park was reconstructed as a luxury playground and the subject’s status is elevated through elite scarcity. With the de- luxe family leisure-field of the 1960s, the consumption of ‘de-luxed’ leisure articulated middle-class family status. Finally, as the liminal pleasure zone of the 1970s and 1980s, a ‘post-lux’ permutation focused on the hedonic individual and a fleeting engagement with place. The thesis thus demonstrates the value of theorising emplacement as a process through which the subjects and archiscapes of representations are co-constituted and change over time.Item Seasonal and altitudinal variations in diet and abundance of the European hare (Lepus europaeus Pallas) in Tongariro National Park, New Zealand : a thesis for the degree of Master of Science in Zoology at Massey University(Massey University, 1979) Horne, Rosemary Sylvia ClaireThe seasonal and altitudinal variations in diet and abundance of European hares (Lepus europaeus) in Tongariro National Park was studied from May 1977 to May 1978. The main study area situated on the northern slopes of Mt. Ruapehu, adjacent to the Bruce Road, extended from 900 m to 1600 m a.s.l. A secondary study area established on the south-western slopes, adjacent to the Ohakune Mountain Road, extended from 700 m to 1500 m a.s.l. Transects were established altitudinally at 100 m intervals. Dietary analysis was undertaken by identification of plant cuticles found within fresh faeces, collected monthly from the area surround each transect. Cuticle analysis results were supplemented by feeding using captive hares, direct field observations of browsed plant species and pellet samples from other areas within the Park. Relationships between seasonal and altitudinal variations in chemical composition and availability of plant species are discussed with reference to dietary changes. Faecal pellet density estimates were made along each transect, defecation rates of captives were determined and the affects of various factors on decomposition rate of pellets is discussed. Results of these three sections are combined to give an estimate of hare abundance. Conclusions are drawn as to the importance of various factors in determining the diet of hares within the Park.Item Comparative ecology of northern brown kiwi (Apteryx australis mantelli) in Tongariro National Park and Tongariro Forest Park, central North Island : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science at Massey University(Massey University, 1995) Miles, J. R. G. (Jonathon Roger Graham)Biological aspects of calling, range size, roost choice, feeding ecology, and potential threats faced by Northern brown kiwi (Apteryx australis mantelli) are described for a 14 month study in two conservation areas in central North Island, Tongariro National Park and Tongariro Forest Park. In Tongariro Forest Park 73% of calls were made by males. The 3:1 ratio of male:female calls changed seasonally, with the proportion of female calls increasing over winter and spring. Total call rates also increased during these seasons. Between nights call rates varied irrespective of season. Temperature and rain accounted for 44% of this variation. During the night, calling behaviour was bimodal, with the majority of calls occurring in the first and last three hours of darkness. In winter and spring males called, on average, 20 minutes later than in summer and autumn. Thirty times more calls hour-1 were heard in Tongariro Forest Park than in Tongariro National Park. Density of kiwi was estimated to be 1 bird/km2 in Tongariro National Park, and 4 birds/km2 in Tongariro Forest Park. This suggests that call rates are not linearly related to the number of kiwi present in an area. Practical implications of this for the interpretation of kiwi call surveys are discussed. Home ranges of kiwi varied from 30.8 to 91.8 ha. Range size of paired females tended to be larger than those of paired males. The range of an unpaired male was significantly larger than those of the paired males and paired females. Female home ranges overlapped more than male home ranges. Kiwi varied considerably in their choice roost. Roost type was dependent on habitat type. Roosts associated with fallen trees and surface roots were the most frequently used type. Kiwi infrequently used one roost site more than once, those roosts that were reused were large burrows of unknown size. Male kiwi used surface vegetation more often than females, while the females favoured roosts associated with hollow logs, and/or roots. Territory size may be a consequence of habitat. During 14 months of sampling, higher numbers and greater taxonomic diversity of invertebrates was found in Tongariro Forest Park than in Tongariro National Park with 55% of taxa common to both areas. Seasonal changes in the taxa found in faeces reflected seasonal changes in apparent invertebrate abundance. Kiwi also appeared to focus on a particular taxon, suggesting that they are selectively opportunistic feeders. Mammalian predators pose a major threat to the long-term survival of kiwi in the central North Island. Predator surveys indicated possums, cats, dogs, and stoats were present in Tongariro Forest Park and Tongariro National Park. A ferret was caught in Tongariro National Park, and pigs were observed only in Tongariro Forest Park, but probably ferrets and pigs are present in both sites. No significant difference was found between the numbers of stoats trapped in the two study areas. Local morphometric variation appeared to occur, with adult male stoats collected in Tongariro National Park being larger, on average, than their counterparts collected in Tongariro Forest Park. There were differences between areas in the average size of prey items with the average size of prey being larger in Tongariro Forest Park than in Tongariro National Park. Future conservation and management issues for Northern brown kiwi are discussed.