Precipitation is one of the atmospheric variables that characterize the climate of a region. The South Island of New Zealand (SI of NZ) has an unusually large number of distinct regional climates and its climatic diversity includes the coldest, wettest, driest and windiest places in New Zealand. This thesis focuses on identifying precipitation trends and rainfall fluctuations for the SI of NZ. First, homogeneity of 184 precipitation series is assessed with the combination of three homogeneity tests (Standard Normal Homogeneity Test, Easterling & Peterson test, Vincent�s Multiple Linear Regression). More than 60% of tested time series are found to contain at least one inhomogeneity. About 50% of the inhomogeneities can be traced to information in the station history files with nearly 25% of all inhomogeneities caused by the relocation of the precipitation gauge. Five coherent precipitation regions are defined by the Principal Component Analysis. The objective of identifying the periods of water deficit and surplus in spatial and temporal domains is achieved by using Standardized Precipitation Index (SPI). The SPI series (for 3, 6, 12, 24 and 48 months time scales) are calculated for each region and used for analysis of dry and wet periods. Clear differences in the frequency, length and intensity of droughts and wet periods were found between individual regions. There is a positive (i.e. increase in wet periods) trend in SPI time series for the North, Westland and Southland regions during the 1921-2003 period at all times scales, and a negative trend for Canterbury during the same period. The results show longer wet periods than dry periods at all time scales. Extreme heavy precipitation, which causes floods, is the most common type of natural disaster accounting for about 40% of all natural disasters worldwide. A set of ten extreme indices is calculated for 51 stations throughout the South Island for the period 1951-2003. The west-east division is found to be the dominant feature of extreme precipitation trends for all extreme indices with more frequent and more intense extreme precipitation in the west/southwest and with a declining trend in the east. The significant decrease in extreme precipitation frequency was detected in Canterbury with 3 days less of precipitation above the long-term 95th percentile by 2003 as compared to 1951. The variability of precipitation, expressed by the SPI, is correlated with local New Zealand atmospheric circulation indices and large-scale teleconnections. The precipitation variability in the South Island is governed largely by the local circulation characteristics, mainly the strength and position of the westerly flow. The increase in precipitation in the West and SouthEast is associated with enhanced westerlies. The correlations between New Zealand�s circulation indices and regional SPI are seasonally robust. The SouthEast region exhibits a strong relationship with the Southern Oscillation Index on seasonal and annual time scales,and with Interdecadal Pacific Oscillation at the decadal scale. The predictability of seasonal precipitation one season ahead is very limited.

The Alpine Fault is the major structure of the Pacific-Australian plate boundary through New Zealand�s South Island. During dextral reverse fault slip, a <5 million year old, ~1 km thick mylonite zone has been exhumed in the hanging-wall, providing unique exposure of material deformed to very high strains at deep crustal levels under boundary conditions constrained by present-day plate motions. The purpose of this study was to investigate the fault zone rheology and mechanisms of strain localisation, to obtain further information about how the structural development of this shear zone relates to the kinematic and thermal boundary constraints, and to investigate the mechanisms by which the viscously deforming mylonite zone is linked to the brittle structure, that fails episodically causing large earthquakes. This study has focussed on the central section of the fault from Harihari to Fox Glacier. In this area, mylonites derived from a quartzofeldspathic Alpine Schist protolith are most common, but slivers of Western Province-derived footwall material, which can be differentiated using mineralogy and bulk rock geochemistry, were also incorporated into the fault zone. These footwall-derived mylonites are increasingly common towards the north. At amphibolite-facies conditions mylonitic deformation was localised to the mylonite and ultramylonite subzones of the schist-derived mylonites. Most deformation was accommodated by dislocation creep of quartz, which developed strong Y-maximum crystallographic preferred orientation (CPO) patterns by prism (a) dominant slip. Formation of this highly-oriented fabric would have led to significant geometric softening and enhanced strain localisation. During this high strain deformation, pre-existing Alpine Schist fabrics in polyphase rocks were reconstituted to relatively well-mixed, finer-grained aggregates. As a result of this fabric homogenisation, strong syn-mylonitic object lineations were not formed. Strain models show that weak lineations trending towards ~090� and kinematic directions indicated by asymmetric fabrics and CPO pattern symmetry could have formed during pure shear stretches up-dip of the fault of ~3.5, coupled with simple shear strains [greater than or equal to]30. The preferred estimate of simple:pure shear strain gives a kinematc vorticity number, W[k] [greater than or equal to]̲ 0.9997. Rapid exhumation due to fault slip resulted in advection of crustal isotherms. New thermobarometric and fluid inclusion analyses from fault zone materials allow the thermal gradient along an uplift path in the fault rocks to be more precisely defined than previously. Fluid inclusion data indicate temperatures of 325+̲15�C were experienced at depths of ~45 km, so that a high thermal gradient of ~75�C km⁻� is indicated in the near-surface. This gradient must fall off to [ less than approximately]l0�C km⁻� below the brittle-viscous transition since feldspar thermobarometry, Ti-inbiotite thermometry and the absence of prism(c)-slip quartz CPO fabrics indicate deformation temperatures did not exceed ~ 650�C at [greater than or equal to] 7.0-8.5�1.5 kbar, ie. 26-33 km depth. During exhumation, the strongly oriented quartzite fabrics were not favourably oriented for activation of the lower temperature basal(a) slip system, which should have dominated at depths [less than approximately]20 km. Quartz continued to deform by crystal-plastic mechanisms to shallow levels. However, pure dislocation creep of quartz was replaced by a frictional-viscous deformation mechanism of sliding on weak mica basal planes coupled with dislocation creep of quartz. Such frictional-viscous flow is particularly favoured during high-strain rate events as might be expected during rupture of the overlying brittle fault zone. Maximum flow stresses supported by this mechanism are ~65 Mpa, similar to those indicated by recrystallised grain size paleopiezometry of quartz (D>25[mu]m, indicating [Delta][sigma][max] ~55 MPa for most mylonites). It is likely that the preferentially oriented prism (a) slip system was activated during these events, so the Y-maximum CPO fabrics were preserved. Simple numerical models show that activation of this slip system is favoured over the basal (a) system, which has a lower critical resolved shear stress (CRSS) at low temperatures, for aggregates with strong Y-maximum orientations. Absence of pervasive crystal-plastic deformation of micas and feldspars during activation of this mechanism also resulted in preservation of mineral chemistries from the highest grades of mylonitic deformation (ie. amphibolite-facies). Retrograde, epidote-amphibolite to greenschist-facies mineral assemblages were pervasively developed in ultramylonites and cataclasites immediately adjacent to the fault core and in footwall-derived mylonites, perhaps during episodic transfer of this material into and subsequently out of the cooler footwall block. In the more distal protomylonites, retrograde assemblages were locally developed along shear bands that also accommodated most of the mylonitic deformation in these rocks. Ti-in-biotite thermometry suggests biotite in these shear bands equilibrated down to ~500+̲50�C, suggesting crystal-plastic deformation of this mineral continued to these temperatures. Crossed-girdle quartz CPO fabrics were formed in these protomylonites by basal (a) dominant slip, indicating a strongly oriented fabric had not previously formed at depth due to the relatively small strains, and that dislocation creep of quartz continued at depths [less than or equal to]20 km. Lineation orientations, CPO fabric symmetry and shear-band fabrics in these protomylonites are consistent with a smaller simple:pure shear strain ratio than that observed closer to the fault core (W[k] [greater than approximately] 0.98), but require a similar total pure shear component. Furthermore, they indicate an increase in the simple shear component with time, consistent with incorporation of new hanging-wall material into the fault zone. Pre-existing lineations were only slowly rotated into coincidence with the mylonitic simple shear direction in the shear bands since they lay close to the simple shear plane, and inherited orientations were not destroyed until large finite strains (<100) were achieved. As the fault rocks were exhumed through the brittle-viscous transition, they experienced localised brittle shear failures. These small-scale seismic events formed friction melts (ie. pseudotachylytes). The volume of pseudotachylyte produced is related to host rock mineralogy (more melt in host rocks containing hydrated minerals), and fabric (more melt in isotropic host rocks). Frictional melting also occurred within cataclastic hosts, indicating the cataclasites around the principal slip surface of the Alpine Fault were produced by multiple episodes of discrete shear rather than distributed cataclastic flow. Pseudotachylytes were also formed in the presence of fluids, suggesting relatively high fault gouge permeabilities were transiently attained, probably during large earthquakes. Frictional melting contributed to formation of phyllosilicate-rich fault gouges, weakening the brittle structure and promoting slip localisation. The location of faulting and pseudotachylyte formation, and the strength of the fault in the brittle regime were strongly influenced by cyclic hydrothermal cementation processes. A thermomechanical model of the central Alpine Fault zone has been defined using the results of this study. The mylonites represent a localised zone of high simple shear strain, embedded in a crustal block that underwent bulk pure shear. The boundaries of the simple shear zone moved into the surrounding material with time. This means that the exhumed sequence does not represent a simple 'time slice' illustrating progressive fault rock development during increasing simple shear strains. The deformation history of the mylonites at deep crustal P-T conditions had a profound influence on subsequent deformation mechanisms and fabric development during exhumation.

Rocks of the South Island of New Zealand are locally enriched in metalloids, namely arsenic (As), antimony (Sb) and boron (B). Elevated levels of As and Sb can be found in sulphide minerals mostly in association with mesothermal gold deposits, whereas B enrichment occurs in marine influenced coal deposits. The mobility of these metalloids is important because they can be toxic at relatively low levels (e.g. for humans >0.01 mg/L of As). Their mobilisation occurs naturally from background weathering of the bedrock. However, mining and processing of coal and gold deposits, New Zealand's most economically important commodities, can significantly increase metalloid mobility. In particular, historic mines and associated industrial sites are known to generate elevated metalloid levels because of the lack of site remediation upon closure. This work defines and quantifies geological, mining, post-mining and regional processes with respect to metalloid, especially As, mobility. At the studied historic gold mines, the Blackwater and Bullendale mines, Sb levels in mineralised rocks were generally negligible (<14 ppm) compared to As (up to 10,000 ppm). Thus, Sb concentrations in solids and in water were too low to yield any meaningful information on Sb mobility. In contrast, dissolved As concentrations downstream from mine sites were found to be very high (up to 59 mg/L) (background = 10⁻� mg/L). In addition, very high As concentrations were found in residues (up to 40 wt%) and site substrate (up to 30 wt%) at the Blackwater processing sites (background < 0.05 wt%). Here, roasting of the gold ore converted the orginal As mineral, arsenopyrite, into the mineral arsenolite (As[III] trioxide polymorph) and volatilised the sulphur. The resultant sulphur-defficient chemical system is driven by arsenolite dissolution and differs significantly from mine sites where arsenopyrite is the main As source. Arsenolite is significantly more soluble than arsenopyrite. In the surficial environment, arsenolite dissolution is limited by kinetics only, which are slow enough to preserve exposed arsenolite over decades in a temperate, wet climate. This process results in surface waters with up to ca. 50 mg/L dissolved As. In reducing conditions, dissolved As concentrations are also controlled by the solubility of arsenolite producing As concentrations up to 330 mg/L. Field based cathodic stripping voltammetry showed that the As[III]/As[V] redox couple, in particular the oxidation of As[III], has a major control on system pH and Eh. Site acidification is mainly caused by the oxidation of As[III], resulting in a close link between As[V] concentrations and pH. Similarly, a strong correlation between calculated (Nernstian) and measured (electrode) Eh was found in the surface environment, suggesting that the overall Eh of the system is, indeed, defined by the As[III]/As[V] redox couple. Once the metalloid is mobilised from its original source, its mobility is controlled by at least one of the following attenuation processes: (a) precipitation of secondary metalloid minerals, (b) co-precipitation with - or adsorption to - iron oxyhydroxide (HFO), or (c) dilution with background waters. The precipitation of secondary minerals is most favoured in the case of As due to the relatively low solubility of iron arsenates, especially at low pH (~0.1 mg/L). Observations suggest that scorodite can be the precursor phase to more stable iron arsenates, such as kankite, zykaite, bukovskyite or pharmacosiderite and their stability is mainly controlled by pH, sulphur concentrations and moisture prevalence. Empirical evidence indicates that the sulphur-containing minerals zykaite and bukovskyite have a similar pH dependence to scorodite with solubilities slightly lower than scorodite and kankite. If dissolved As concentrations decline, iron arsenates potentially become unstable. Their dissolution maintains a pH between 2.5 and 3.5. This acidification process is pivotal with respect to As mobility, especially in the absence of other acidification processes, because iron arsenates are several orders of magnitude more soluble in circum-neutral pH regimes (~100 mg/L). From this, it becomes apparent that external pH modifications, for example as part of a remediation scheme, can significantly increase iron arsenate solubility and resultant As mobility. In contrast to As, the precipitation of secondary Sb and B minerals is limited by their high solubilities, which are several orders of magnitude higher than for iron arsenates. Thus, secondary Sb and B minerals are restricted to evaporative waters, from which they can easily re-mobilised during rain events. Metalloid adsorption to HFO is mainly controlled or limited by the extent of HFO formation, which in turn is governed by the availability of Fe and prevailing Eh-pH conditions. Thus, mineralisation styles and associated geochemical gradients, in particular pyrite abundance, can control the amount of HFO and consequent metalloid attenuation, and these can vary even within the same goldfleld. Furthermore, it was found that there is a mineralogical gradation between ferrihydrite with varying amounts of adsorbed As, amorphous iron arsenates and crystalline iron arsenates, suggesting that the maturity of mine waste is an important factor in As mineralogy. Once dissolved metalloids enter the hydrosphere, dilution is the main control on metalloid attenuation, which is especially pronounced at the inflow of tributaries. Dilution is, therefore, closely related to the size and frequency of these tributaries, which in turn are controlled by the regional topography and climate. Dilution is a considerably less effective attenuation mechanism and anomalous metalloid concentrations from mining related sites can persist for over 10 km downstream. The complex and often inter-dependent controls on metalloid mobility mean that management decisions should carefully consider the specific site geochemistry to minimize economic, health and environmental risks that can not be afforded. On a regional scale, background metalloid flux determines the downstream impact of an anomalous metalloid source upstream. For example, the Bullendale mine is located in a mountainous region, where rapidly eroding slopes expose fresh rock and limit the extent of soil cover and chemical weathering. Consequently, the background As flux is relatively low and As point sources, such as the Bullendale mine, present a significant contribution to the downstream As flux. In contrast, the bedrock at the Blackwater mine has undergone deep chemical weathering, resulting in an increased background mobilisation of As. Thus, the Prohibition mill site discharge, for example, contributes only about 10% to the downstream As flux. This information is relevant to site management decisions because the amount of natural background metalloid mobilisation determines whether site remediation will influence downstream metalloid chemistry on a regional scale.

The current explanation for the absence, or low abundance, of filter-feeding invertebrates from some rocky shores is that because of local variation in nearshore oceanographic conditions, larvae do not arrive in sufficient numbers to establish populations. One putative consequence of this is that macroalgae are able to establish dominance in areas where filter-feeders (especially mussels) do not recruit well. While macroalgae have been transplanted to mussel-dominated shores with varying success, the survival, growth and reproduction of transplanted mussels has not been tested in areas dominated by macroalgae. To determine specifically what tips the balance between shores dominated by filter-feeding invertebrates and those dominated by macroalgae, I monitored the recruitment of intertidal mussels at four sites on the Kaikoura coast: two with mussels present and two algal-dominated. No significant differences in mussel recruitment rates were found between habitats and recruitment intensity at all sites was found to be very low. Recruitment limitation is not the reason for the absence of mussels from algal dominated shores but some form of limitation does occur to reduce the number of arriving mussels. Predation effects were examined by transplanting juvenile mussels into caged, uncaged and control treatments. No significant differences in predation rates between habitats were found and transplanted mussels in open cages at all sites were removed within 3 days. Mobile fish predators appeared to be the most likely cause of this intense predation. Growth of transplanted mussels into algal and mussel habitats was found to be significantly different. Mussels grew faster in mussel dominated habitats and after 6 months in algal dominated habitats, all mussels had died. The outcome of these experiments indicates that there is a close relationship between recruitment, survival and growth which tips the balance and allows the existence of mussel beds along the Kaikoura coastline.

The choice of a place to live and reproduce is crucial for species� survival in providing them with adequate resources and shelter from predators or climatic conditions. Determining habitat suitability in endangered species is important for the success of translocation as a conservation tool. In addition, understanding mechanisms (source/sink system versus ecological traps) that drive habitat selection in translocated animals may be critical to population viability. In New Zealand, where ecosystems are highly vulnerable to extinction, habitat restoration on predator-free off-shore islands is an important recovery tool. Therefore, there is a need to understand the relationship between the establishment of the translocated populations and the characteristics of their new environment. Previous research indicated that re-introduced populations of Stewart Island robin (Petroica australis rakiura - Toutouwai) and South Island saddleback (Philesternus carunculatus carunculatus - Tieke) on Ulva Island (Stewart Island), New Zealand, showed preferences for coastal habitats that were characterized by low-lying dense vegetation and open ground cover. In this study, we further investigated territorial establishment in these two populations since re-introduction and looked at how birds utilised the landscape. I hypothesised that sites colonised soon after re-introduction were of high quality and later on, birds moved into unsuitable habitats. I defined habitat quality at a micro-scale in terms of vegetation structure, nest characteristics and food availability. I modeled bird presence and nesting success in relation to habitat components to determine factors in the environment that influenced breeding site selection and contributed to successful nesting in these two species. I discussed results in comparison to similar bird-habitat models developed for the South Island saddleback population on Motuara Island (Marlborough Sounds) and examined explanatory variables in each model. Translocated birds in the three studied populations first established territories in coastal scrub, and in the following years moved into larger coastal forest stands. Although vegetation structure was the primary variable explaining site selection in these populations, vegetation composition should still be considered important as it dictated the suitability of nesting substrate and the availability of food items. There was no evidence that first-colonised areas were more suitable habitats, and I concluded that these cases could not be used as examples of ecological traps. Instead, results suggested that with increased density robins and saddlebacks on Ulva have more recently settled in sites less suitable to nesting and foraging, thus underlying a source/sink structure. However, the sparse distribution of food items on Motuara contributed to a lack of territorial behavior and environmental effect on breeding success; therefore a source/sink system could not be confirmed in this population. I recommended that future translocation sites give preference to mixed-size stands with broadleaved species that are characterised by dense canopy below 4 m height and with suitable cavities in live trees. Lastly, due to robins� and saddlebacks� attraction to conspecifics and their territorial behavior, resources evenly distributed across the landscape could also increase their survival and reproductive success.

The transformation of the rangelands of the South Island of New Zealand during the pastoral era fits into the wider international context of European expansion into the 'new' world. European settlers displaced native peoples, introduced 'old' world animals and plants, and imposed a capitalist system that converted local resources into international commodities. In New Zealand the orthodox explanation of the pastoral impact on the rangelands claims that pastoralists introduced an unsustainable system of land use to the region. The pastoralists� indiscriminate burning practices and overstocking with sheep opened up the country to invasion by rabbits. Burning and overgrazing by sheep and rabbits stripped the natural fertility of the soils and left the country depleted, eroded, and overwhelmed by pests and weeds. This thesis sets out to test those claims. It explores burning, the stocking of the rangelands with sheep and the impact of rabbits in detail. It also examines other land management practices, as well as sheep breeding, to see what impact they had on the landscape. The timeframe is set between 1841, when formal British settlement was established in the South Island, and 1912, by which time most of the great estates and stations had been broken up into smaller runs and farms. The thesis uses station diaries, memoirs, contemporary newspapers and farming journals to assess what happened on the ground during the pastoral era. In particular, the thesis uses Mt Peel Station as a case study to examine the intensification in land use that took place between 1841 and 1912, in order to explain the transformation of the landscape and to answer the questions: what happened, how did it happened and why did it happened as it did? These sources illustrate that the pastoral era was characterised by innovation. Pastoralists had access to technical and scientific information from around the world. Some conducted their own experiments to improve the productivity of the land and their stock. There was also a learning process involved in adapting their methods to fit the local rangeland environments. They were not simply rapacious capitalists out to strip the wealth from the land for their own personal gain; indeed, many pastoralists set out to establish viable and sustainable enterprises. The thesis argues that the rangelands consisted of a variety of landscapes and climates. Differences in resource endowments had a considerable influence in shaping the environmental outcomes on different stations. Aridity and rabbits were two key factors in the depletion of the vegetation and the degradation of the landscape in the rangelands. Runs in semi-arid districts that were overwhelmed by rabbits suffered long-term damage. In districts where rainfall was more reliable stations that had been overrun by rabbits recovered remarkably quickly. Stations like Mt Peel, that were largely unaffected by the first rabbit plague, were able to maintain and even increase their productivity up to the time they were subdivided. The orthodox analysis of the transformation of the rangelands in the pastoral era does not account for these differences in outcomes.

Nutrients for plant growth are often limited in soil systems and additions are required in the form of fertiliser. Potassium is an essential macro-nutrient for plants and demands for K are expected to increase in the future. Glaucony is an abundant marine mineral which may provide an alternative K-rich fertiliser resource. The South Island of New Zealand contains deposits of glaucony-rich rocks which were deposited in the Early- to Mid-Cenozoic during periods of low sedimentation to the seafloor. Here, the geochemistry of glaucony from the Waitaki Basin (Otago), the Waipara Greensand (North Canterbury) and the Stoney Creek Limestone (Karamea) was examined using spatially resolved geochemical analysis and dissolution experiments. Grain-by-grain analysis using Laser Ablation Induction Coupled Plasma Mass Spectrscopy (LA-ICP-MS) and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM + EDS) revealed that glaucony from all deposits were of the mature type and were enriched in K. Glaucony derived from growth inside faecal pellets was found to contain elevated K and Fe concentrations compared to bioclast hosted glaucony. These variations can be explained by the physical properties of host grains and sea-floor redox conditions at the time of precipitation, both of which increased ionic mobility into the zone of glauconitisation. Solubility analysis showed that K^{+} was released from glaucony more rapidly than any other element. Additionally, decreasing the pH and introducing an oxidising agent (i.e, birnessite which is ubiquitous in soil environments) accelerated K^{+} release 13-fold. Trace metals including Cr, Zn, Cu and Ni were present in the solid phase analysis, however further investigation revealed that these elements were released into solution in low concentrations and may present a source of micro-nutrients, not a soil contaminant. These results suggest that glaucony may offer a source of slow releasing K fertiliser, and the South Island of New Zealand is ideally situated as a place to consider using glaucony as a locally sourced, environmentally sustainable K resource for agriculture.

Cyanobacteria can form nuisance proliferations and produce large concentrations of toxins that pose a health hazard. This thesis investigates cyanotoxin production by New Zealand benthic cyanobacteria. Cyanobacteria were sampled from lakes, reservoirs, streams, and rivers. Thirty-five strains were isolated into culture and screened for genes involved in the biosynthesis of common cyanotoxins. Positive results were confirmed and cyanotoxin concentrations quantified using analytical chemistry techniques. Genes involved in anatoxin a/homoanatoxin a biosynthesis were detected in nine out of ten Phormidium cf. uncinatum strains isolated from a single mat. Anatoxin a was confirmed in these strains by LC–MS/MS at concentrations from 0.3 to 6.4 mg kg⁻¹. One strain also produced homoanatoxin-a. Anatoxin-a variation between strains may explain the wide range in anatoxin a concentrations previously observed in New Zealand. The sxtA gene involved in saxitoxin biosynthesis was identified in Scytonema cf. crispum strains. Saxitoxin was confirmed in strains and environmental samples by Jellett PSP Rapid Test and HPLC–FD. Gonyautoxins, neosaxitoxin, and decarbamoyl derivatives were also detected. This study is the first identification of these compounds in Scytonema and in New Zealand cyanobacterial strains. These strains were isolated from recreational and pre-treatment drinking water reservoirs, highlighting the risk benthic cyanobacteria pose to human and animal health. Experiments were undertaken using cultures of Phormidium and Scytonema to determine how growth influences cyanotoxin production. The effects of iron and copper stress on P. autumnale were also investigated. High iron concentrations disrupted attachment mechanisms. Iron and copper had a significant effect on growth, without significantly affecting anatoxin a production. However, the maximum anatoxin a quota was consistently observed during early exponential growth. Scytonema cf. crispum produced higher saxitoxin quota throughout exponential growth than during the stationary phase. Both the Phormidium and Scytonema growth experiments indicate that high toxin quota can be expected early in benthic mat development, making early detection of these proliferations important.

The choice of a place to live and reproduce is crucial for species� survival in providing them with adequate resources and shelter from predators or climatic conditions. Determining habitat suitability in endangered species is important for the success of translocation as a conservation tool. In addition, understanding mechanisms (source/sink system versus ecological traps) that drive habitat selection in translocated animals may be critical to population viability. In New Zealand, where ecosystems are highly vulnerable to extinction, habitat restoration on predator-free off-shore islands is an important recovery tool. Therefore, there is a need to understand the relationship between the establishment of the translocated populations and the characteristics of their new environment. Previous research indicated that re-introduced populations of Stewart Island robin (Petroica australis rakiura - Toutouwai) and South Island saddleback (Philesternus carunculatus carunculatus - Tieke) on Ulva Island (Stewart Island), New Zealand, showed preferences for coastal habitats that were characterized by low-lying dense vegetation and open ground cover. In this study, we further investigated territorial establishment in these two populations since re-introduction and looked at how birds utilised the landscape. I hypothesised that sites colonised soon after re-introduction were of high quality and later on, birds moved into unsuitable habitats. I defined habitat quality at a micro-scale in terms of vegetation structure, nest characteristics and food availability. I modeled bird presence and nesting success in relation to habitat components to determine factors in the environment that influenced breeding site selection and contributed to successful nesting in these two species. I discussed results in comparison to similar bird-habitat models developed for the South Island saddleback population on Motuara Island (Marlborough Sounds) and examined explanatory variables in each model. Translocated birds in the three studied populations first established territories in coastal scrub, and in the following years moved into larger coastal forest stands. Although vegetation structure was the primary variable explaining site selection in these populations, vegetation composition should still be considered important as it dictated the suitability of nesting substrate and the availability of food items. There was no evidence that first-colonised areas were more suitable habitats, and I concluded that these cases could not be used as examples of ecological traps. Instead, results suggested that with increased density robins and saddlebacks on Ulva have more recently settled in sites less suitable to nesting and foraging, thus underlying a source/sink structure. However, the sparse distribution of food items on Motuara contributed to a lack of territorial behavior and environmental effect on breeding success; therefore a source/sink system could not be confirmed in this population. I recommended that future translocation sites give preference to mixed-size stands with broadleaved species that are characterised by dense canopy below 4 m height and with suitable cavities in live trees. Lastly, due to robins� and saddlebacks� attraction to conspecifics and their territorial behavior, resources evenly distributed across the landscape could also increase their survival and reproductive success.

The transformation of the rangelands of the South Island of New Zealand during the pastoral era fits into the wider international context of European expansion into the 'new' world. European settlers displaced native peoples, introduced 'old' world animals and plants, and imposed a capitalist system that converted local resources into international commodities. In New Zealand the orthodox explanation of the pastoral impact on the rangelands claims that pastoralists introduced an unsustainable system of land use to the region. The pastoralists� indiscriminate burning practices and overstocking with sheep opened up the country to invasion by rabbits. Burning and overgrazing by sheep and rabbits stripped the natural fertility of the soils and left the country depleted, eroded, and overwhelmed by pests and weeds. This thesis sets out to test those claims. It explores burning, the stocking of the rangelands with sheep and the impact of rabbits in detail. It also examines other land management practices, as well as sheep breeding, to see what impact they had on the landscape. The timeframe is set between 1841, when formal British settlement was established in the South Island, and 1912, by which time most of the great estates and stations had been broken up into smaller runs and farms. The thesis uses station diaries, memoirs, contemporary newspapers and farming journals to assess what happened on the ground during the pastoral era. In particular, the thesis uses Mt Peel Station as a case study to examine the intensification in land use that took place between 1841 and 1912, in order to explain the transformation of the landscape and to answer the questions: what happened, how did it happened and why did it happened as it did? These sources illustrate that the pastoral era was characterised by innovation. Pastoralists had access to technical and scientific information from around the world. Some conducted their own experiments to improve the productivity of the land and their stock. There was also a learning process involved in adapting their methods to fit the local rangeland environments. They were not simply rapacious capitalists out to strip the wealth from the land for their own personal gain; indeed, many pastoralists set out to establish viable and sustainable enterprises. The thesis argues that the rangelands consisted of a variety of landscapes and climates. Differences in resource endowments had a considerable influence in shaping the environmental outcomes on different stations. Aridity and rabbits were two key factors in the depletion of the vegetation and the degradation of the landscape in the rangelands. Runs in semi-arid districts that were overwhelmed by rabbits suffered long-term damage. In districts where rainfall was more reliable stations that had been overrun by rabbits recovered remarkably quickly. Stations like Mt Peel, that were largely unaffected by the first rabbit plague, were able to maintain and even increase their productivity up to the time they were subdivided. The orthodox analysis of the transformation of the rangelands in the pastoral era does not account for these differences in outcomes.