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Productive housing: Exploring potential at the intersection of housing and highly productive land in New Zealand : A dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Landscape Architecture at Lincoln University
Get PDFAotearoa New Zealand’s most productive soils are under threat from urban sprawl, and in particular by the subdivision of rural land for low to medium-density housing developments. Although strategic planning is undertaken by district councils to identify city limits and the best areas for urban expansion, district plans can be challenged privately by developers, through a ‘plan change request’ process.
Plan Change 69 (PC69) is one of many developer-led proposals in the Selwyn District seeking to rezone rural land for residential development. Using PC69 as a case study, this research investigates opportunities to reconcile the demand for housing and the preservation of highly productive land. The study uses a ‘design thinking’ framework, first seeking to understand the sentiment of the existing community, then responding with potential design scenarios based on relevant urban design theory. The purpose of this design research, rather than finding a singular and conclusive solution, is to provide multiple opportunities as a source for discussion, debate and future research. Alongside the PC69 proposal, three possible alternative futures are identified which explore potential at the intersection of housing and food, and the implications of prioritising one dimension over another. These highlight that there is potential to integrate both housing and food on highly productive land, though to achieve this, we may need to embrace residential models that differ from the current low-density approach applied in most peri-urban greenfield sites in Aotearoa
Breeding movements and post-breeding dispersal of Black-fronted terns/Tarapirohe (Chlidonias albostriatus) in the Mackenzie Basin : A thesis submitted in partial fulfilment of the requirements for the Degree of Master of Science at Lincoln University
Get PDFBlack-fronted terns/Tarapirohe (Chlidonias albostriatus) are endemic to New Zealand, where they are currently listed as a nationally endangered species due to their small and declining population. They breed almost exclusively in braided rivers in the east of the South Island, where they are vulnerable to several threats, particularly introduced mammalian predators. Current conservation is focused almost exclusively on controlling mammalian predators around black-fronted tern colonies. Conservation actions away from breeding colonies are hindered by large knowledge gaps around habitat preferences while foraging, foraging range, and migration routes away from colony sites and significant wintering areas.
This study used GPS trackers to follow the movements of black-fronted terns, the first time this technology has been applied to this species. In November and December 2020, 34 black-fronted terns were caught and fitted with GPS devices in colonies in the Cass and Ohau rivers of the Mackenzie Basin. During the 2020/2021 breeding season, these terns primarily foraged in high-producing exotic grassland (irrigated paddocks) and avoided areas of low producing and depleted grassland. While foraging, the terns spent 87.6% of their time within 10 km of the breeding colonies and >99% of their time within 25 km of their breeding colonies. One individual black-fronted tern was tracked to 92.2 km from its breeding colony, visiting three major river systems in 24 hours. The mean GPS point distance from the breeding colony was significantly higher for terns from the Ohau compared to terns from the Cass, likely due to favoured foraging areas of high producing exotic grassland being further from the Ohau colony than this habitat is from the Cass colony. Terns from both colonies were found to have nocturnal roosting areas at river deltas near their respective colonies, the first evidence of breeding black-fronted terns roosting away from their breeding areas at night.
Following the breeding season, the terns left the Mackenzie Basin by flying overland to the lower Rangitata River or down the Waitaki River to its lower reaches. Before the GPS device batteries failed the terns spent time in and around the lower reaches of east coast braided rivers, particularly the lower Rangitata River. Further research is required to gain an understanding of black-fronted tern movements year-round, particularly during winter. The results of this study indicate that areas of high producing exotic grassland within 10 km of breeding colonies are important to breeding black-fronted terns, as are nocturnal roosts at nearby river deltas. These identified areas should be prioritised for new conservation actions
An analysis of the implications of circular economy principles on waste generation in the New Zealand construction sector : A dissertation submitted in partial fulfilment of the requirements for the Degree of Master at Lincoln University
Get PDFThe New Zealand Government and the Ministry for the Environment have recently proposed a new founding set of principles to guide the development of environmental policies, plans and strategies. The new guiding principles have moved away from a focus on sustainable development, to a focus on the circular economy approach. This is an approach that creates a resource-utilised economy, and promotes the close-loop of resource lifespans. As a result of this progression, the Ministry for the Environment is proposing a new waste strategy, and new and more comprehensive legislation on waste, to replace the current national waste strategy and the Waste Minimisation Act (2008).
This research took a qualitative approach and aimed to analyse the new waste strategy consultation document Taking Responsibility for our Waste, and its guiding circular economy principles, with a particular focus on how the principles could apply to the construction and demolition (C&D) sector and its waste streams. This analysis looked at the content of the consultation document, and at submissions to the Environment Select Committee’s briefing on construction and demolition waste launched in June 2021, as well as interviewing a range of stakeholders in the C&D industry to assess the challenges involved in applying circular economy principles in this sector. The results identified a range of barriers that are likely to impede application of circular economy principles in the high-waste construction industry, and concludes that the best course of action forward is for collaboration and incentives to industries
Implementing biosecurity in live plant trade networks : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
Get PDFNew Zealand faces unique challenges with regards to invasive species due to a high number of endemic species and correspondingly high risk for the decline of indigenous species as a result of invasive introductions. Many of these introductions have been facilitated by human mediated transport, which promotes long range movement of plants and associated pests and pathogens. The transportation of these invasive species to new environments can negatively affect native plants, crops, and industries reliant on plant production. In particular, live plant trade networks represent effective mediums to disseminate invasive species such as pathogens, pests, and weeds. The movement of live plants through professional nurseries and private retailers in New Zealand is yet to be fully investigated. Performing an assessment of contact structures derived from live plant trades can be used to prevent the introduction and spread of invasive species, thereby safeguarding both businesses and the environment. Network analysis provides suitable tools to study live plant trade systems, such as the bilateral plant nursery network, as well as the itinerary online sales network. Fundamental characteristics related to geographic distribution of plant sales (such as location of origin and destination) and key metrics related to plant product movement within live plant trade networks need to be examined in order to better understand the nature of this structure.
This thesis addresses gaps in knowledge related to live plant trade in New Zealand by generating networks that characterise human-mediated movement of horticultural products. Subsequently, developing network models of such systems was used to determine their vulnerability to invasive species acquisition and spread. This was accomplished via the assessment of three live plant trade systems of particular relevance to New Zealand biosecurity. These studies thusly characterise the forestry nursery transport network, the initial incursion of the invasive plant pathogen myrtle rust (Austropuccinia psidii) into New Zealand, and plant sales facilitated by the New Zealand-based online retailer Trade Me.
Firstly, assessment of the forestry nursery transport network described the movement of product from seed orchards to nurseries to plantation forests and the biosecurity protocols in place at forestry nurseries. This study identifies seed orchards as the point of production most likely to facilitate widespread dispersal of a pathogen through the industry. The second study system, assessment of the initial incursion of myrtle rust into New Zealand, characterises the sale of nursery plants from myrtle rust positive nurseries during the first three months of the incursion. These networks identified a lack of comprehensive record keeping at ornamental nurseries as a risk for future invasions that are facilitated by contaminated nursery stock. Additionally, assessment of all myrtle rust positive locations during the first two years of the incursion identified delimiting surveys as a highly successful surveillance tool that would benefit from more research into optimisation of the survey radius depending on the nature of the invasive. The third and final study system, which characterised plant sales facilitated by Trade Me, employed the networking of plant sales based on their subcategorisation on the Trade Me site (into one of nine subcategories chosen by Trade Me) as well as the suburb of residence for both the seller and buyer of a product. Additionally, an assessment of the most common taxa sold on the site was conducted. The information derived from this study can be adopted for immediate use in biosecurity responses in the event of an introduction of an unwanted pest or pathogen vectored on ornamental plants, as well as identify the plant product classes at highest risk for long-distance dispersal
Selection for early shoot vigour in wheat increases root hair length but reduces epidermal cell size of roots and leaves
No full textSix cycles of recurrent selection for early shoot vigour in wheat resulted in significant increases in leaf width and shoot biomass. Here, in replicated controlled-environment studies, the effect of early shoot vigour on root biomass, rhizosheath size, root hair length, and cell size in the roots and leaves was examined across different cycles of selection. Increased shoot vigour was associated with greater root biomass, larger rhizosheath size, and longer root hairs. Our findings demonstrate that rhizosheath size was a reliable surrogate for root hair length in this germplasm. Examination of the root epidermis revealed that the 'cell body' of the trichoblasts (hair-forming cells) and the atrichoblasts (non-hair-forming cells) decreased in size as shoot vigour increased. Therefore, in higher vigour germplasm, longer root hairs emerged from smaller trichoblasts so that total trichoblast volume (root hair plus cell body) was generally similar regardless of shoot vigour. Similarly, the sizes of the four main cell types on the leaf epidermis became progressively smaller as shoot vigour increased, which also increased stomatal density. The relationship between shoot vigour and root traits is considered, and the potential contribution of below-ground root traits to performance and competitiveness of high vigour germplasm is discussed
Schindler's legacy: From eutrophic lakes to the phosphorus utilization strategies of cyanobacteria
No full textDavid Schindler and his colleagues pioneered studies in the 1970s on the role of phosphorus in stimulating cyanobacterial blooms in North American lakes. Our understanding of the nuances of phosphorus utilization by cyanobacteria has evolved since that time. We review the phosphorus utilization strategies used by cyanobacteria, such as use of organic forms, alternation between passive and active uptake, and luxury storage. While many aspects of physiological responses to phosphorus of cyanobacteria have been measured, our understanding of the critical processes that drive species diversity, adaptation and competition remains limited. We identify persistent critical knowledge gaps, particularly on the adaptation of cyanobacteria to low nutrient concentrations. We propose that traditional discipline-specific studies be adapted and expanded to encompass innovative new methodologies and take advantage of interdisciplinary opportunities among physiologists, molecular biologists, and modellers, to advance our understanding and prediction of toxic cyanobacteria, and ultimately to mitigate the occurrence of blooms
Extent and intensity of vehicle-use impacts within a saltmarsh conservation area under a management strategy
No full textSaltmarshes provide multiple ecosystem services, and some have been preserved as conservation areas. Studies indicate recreation-related vehicle use may be significantly degrading them. Saltmarshes have a low resistance and resilience to recreation-related trampling impacts; however, little is known about those associated with vehicle use under a specific management strategy. Drone imagery and GIS spatial analysis were used to determine the area and intensity of direct vehicle impacts within a New Zealand saltmarsh. The management plan allows vehicle entry as long as it does not substantially impact cultural, ecological, or mahinga kai (or food cultivation) values. It limits impacts of vehicles by meeting two goals: limiting the area of vehicle use to formal road corridors, and limiting particularly damaging behaviors of use, including entering the saltmarsh when conditions are wet, traveling more than 10 km per hour, and using traction equipment. Results demonstrated substantial impacts. Tire tracks were present in 66% of quadrats sampled, and were distributed across the length and breadth of the saltmarsh, covering 17% (approximately 207 ha) of the 1225 ha saltmarsh. About a third of these quadrats had track covers of 11-50%. Furthermore, particularly damaging vehicle use behaviors were widely evidenced, including deeply rutted mud, water channel initiation, and substantial loss and fragmentation of vegetation communities. Vehicle use is clearly eroding at least some of the cultural, ecological, and/or mahinga kai values for which the saltmarsh was conserved. While there are many indirect and direct measures for improving the current management strategy, none is likely to result in substantial reductions in vehicle impacts given the low resistance and resilience of saltmarshes to trampling. An alternative strategy that would lead to substantial reductions, and eventual recovery of the saltmarsh, would be to allow existing recreational activities, but deny vehicle entry
Exploring visiting friends and relative (VFR) hosts' decision-making in hospitality provision
No full textDue to the kinship ties existing between hosts and guests, any VFR host is likely to experience elevated levels of stress in preparing for such encounters because of the desire to deliver a good experience to their guests. As such, existing literature has sought to unpack VFR hosting behaviour and practices, albeit mostly from an Anglo-Saxon perspective. However, little is known about the influence of East Asian cultures and gendered perspectives of Visiting Friends and Relatives (VFR) hosting behaviour and practices, which is underrepresented within extant literature. From a sample of 91 Taiwanese hosts based in Brisbane, Australia, this research suggests that accommodation considerations are a main factor to Taiwanese VFR hosts in Australia, and that first-time VFR tourists also warrant heightened hosting efforts. These findings contribute to a more nuanced understanding of how East Asian and gendered lenses of VFR hosting behaviour manifests, positions these individuals as potential destination ambassadors, and strategically launch post COVID-19 tourism recovery
Early effects of surface liming on soil P biochemistry and dynamics in extensive grassland
No full textLiming effects on soil phosphorus (P) availability via biological P cycling are not clear. We conducted an 18-month field experiment on a long-term (60 years +) permanent fertilized grassland in a relatively dry environment. The aim was to examine the impact of liming on P biochemical processes and dynamics. Lime was applied at the beginning of the experiment to produce a soil pH range of 5.4–7.0, with no fertilizer P treatments. Soil sampling was conducted throughout the experimentation period at 0–75 mm. All soils were analysed for moisture content, pH, Olsen P, resin P, exchangeable aluminium (Al), microbial biomass P (MBP) and enzyme activities. At the final sampling, the soil samples were analysed for total C, total N and anaerobic mineralizable N (AMN). A sequential P fractionation was conducted for 0–30 mm depth samples. Liming effects on soil pH and P processes were limited to the surface 30 mm only, where labile inorganic P (Pᵢ) fraction increased by 42% at pH 7.0 compared to pH 5.4, while labile and moderately labile organic P (Pₒ) decreased by 33% and 25%, respectively. Strong positive relationships were found between microbial P and: soil pH, labile Pᵢ, total C and AMN. Absolute activities of acid and alkaline phosphomonoesterases were not affected by liming. However, their specific activity decreased by 47% and 28%, respectively at pH 7.0 compared to pH 5.4. Absolute enzyme activity of phosphodiesterase correlated strongly and positively with labile Pᵢ. Our findings demonstrate that liming enhances plant P availability under field conditions in long-term fertilized extensive grassland. However, the effects are limited to near-surface depths in the soil
Continuous flow vortex fluidic transformation of kombucha cellulose into more compact and crystalline fibers
No full textA chemical-free and scalable novel route for generating more compact and crystalline cellulose from cellulosic biofilms formed at the air-water interface as an otherwise waste byproduct from the kombucha tea beverage fermentation industry has been developed. This involves processing the byproduct by treatment with aqueous 1 M NaOH at 50 °C and then 1% glacial acetic acid followed by washing with distilled water until the pH of the washing water is 7, followed by continuous flow processing in the vortex fluidic device (VFD). This thin-film microfluidic platform houses a 20 mm outside diameter and 17.5 mm inside diameter quartz tube with a hemispherical base. The induced high shear mechanical energy arising from the topological fluid flows within the thin film when the tube is tilted at θ +45° and spun at ω 6k rpm converts the kombucha cellulose to smaller fiber diameters ∼70 nm cf. ∼127 nm preVFD processing. The material is characterized using dynamic light scattering, scanning electron microscopy, atomic force microscopy, X-ray diffraction, thermogravimetric analysis/differential scanning calorimetry, Fourier transform infrared, and Brunauer-Emmett-Teller. The modification of the cellulose is understood mechanistically by the high shear topological fluid flow from the Coriolis force from the base of the tube, forcing the individual cellulose polymer strands together in an ordered array. Such transient localized high shear flow associated with high temperatures and pressures over the fibers on the surface of the tube force the backbone long cellulose strands together resulting in increased crystallinity. The findings lay the foundation for transforming a byproduct from kombucha tea beverage fermentation into unique material for other applications