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Research Papers, Lincoln University

Mixed conifer, beech and hardwood forests are relatively common in Aotearoa/New Zealand, but are not well studied. This thesis investigates the coexistence, regeneration dynamics and disturbance history of a mixed species forest across an environmental gradient of drainage and soil development in north Westland. The aim was to investigate whether conifers, beech and non-beech hardwood species were able to coexist on surfaces that differed in their underlying edaphic conditions, and if so to understand the mechanisms that influenced their regeneration on both poorly drained and well drained soils. The site selected was an area of high tree species diversity on a lowland 0.8 km² post-glacial terrace at the base of Mount Harata in the Grey River Valley. My approach was to use forest stand history reconstruction at two spatial scales: an intensive within-plot study of stand dynamics (chapter 1) and a whole-landform approach (chapter 2) that examined whether the dynamics identified at the smaller within-plot scale reflected larger patterns across the terrace. In chapter 1, three large permanent plots (0.3-0.7 ha) were placed at different points along the drainage gradient, one plot situated in each of the mainly well-drained, poorly drained and very poorly drained areas along the terrace. Information was gathered on species age and size structures, spatial distributions of tree ages, species interactions, microsite establishment preferences, patterns of stand mortality, and disturbance history in each plot. There were differences in stand structure, composition and relative abundance of species found between the well drained plot and the two poorer drained plots. On the well drained site conifers were scarce, the beeches Nothofagus fusca and N. menziesii dominated the canopy, and in the subcanopy the hardwood species Weinmannia racemosa and Quintinia acutifolia were abundant. As drainage became progressively poorer, the conifers Dacrydium cupressinum and Dacrycarpus dacrydioides became more abundant and occupied the emergent tier over a beech canopy. The hardwoods W. racemosa and Q. acutifolia became gradually less abundant in the subcanopy, whereas the hardwood Elaeocarpus hookerianus became more so. In the well drained plot, gap partitioning for light between beeches and hardwoods enabled coexistence in response to a range of different sized openings resulting from disturbances of different extent. In the two more poorly drained plots, species also coexisted by partitioning microsite establishment sites according to drainage. There were several distinct periods where synchronous establishment of different species occurred in different plots, suggesting there were large disturbances: c. 100yrs, 190-200 yrs, 275-300 yrs and 375-425 yrs ago. Generally after the same disturbance, different species regenerated in different plots reflecting the underlying drainage gradient. However, at the same site after different disturbances, different sets of species regenerated, suggesting the type and extent of disturbances and the conditions left behind influenced species regeneration at some times but not others. The regeneration of some species (e.g., N. fusca in the well-drained plot, and Dacrydium in the poorer drained plots) was periodic and appeared to be closely linked to these events. In the intervals between these disturbances, less extensive disturbances resulted in the more frequent N. menziesii and especially hardwood regeneration. The type of tree death caused by different disturbances favoured different species, with dead standing tree death favouring the more shade-tolerant N. menziesii and hardwoods, whereas uprooting created a mosaic of microsite conditions and larger gap sizes that enabled Dacrycarpus, N. fusca and E. hookerianus to maintain themselves in the poorly drained areas. In chapter 2, 10 circular plots (c. 0.12 ha) were placed in well drained areas and 10 circular plots (c. 0.2 ha) in poorly drained plots to collect information on species population structures and microsite preferences. The aims were to reconstruct species' regeneration responses to a range of disturbances of different type and extent across the whole terrace, and to examine whether there were important differences in the effects of these disturbances. At this landform scale, the composition and relative abundances of species across the drainage gradient reflected those found in chapter 1. There were few scattered conifers in well drained areas, despite many potential regeneration opportunities created from a range of different stand destroying and smaller scale disturbances. Three of the four periods identified in chapter 1 reflected distinct terrace-wide periods of regeneration 75-100 yrs, 200-275 yrs and 350-450 yrs ago, providing strong evidence of periodic large, infrequent disturbances that occurred at intervals of 100-200 yrs. These large, infrequent disturbances have had a substantial influence in determining forest history, and have had long term effects on forest structure and successional processes. Different large, infrequent disturbances had different effects across the terrace, with the variability in conditions that resulted enabling different species to regenerate at different times. For example, the regeneration of distinct even-aged Dacrydium cohorts in poorly drained areas was linked to historical Alpine Fault earthquakes, but not to more recent storms. The variation in the intensity of different large, infrequent disturbances at different points along the environmental drainage gradient, was a key factor influencing the scale of impacts. In effect, the underlying edaphic conditions influenced species composition along the drainage gradient and disturbance history regulated the relative abundances of species. The results presented here further emphasise the importance of large scale disturbances as a mechanism that allows coexistence of different tree species in mixed forest, in particular for the conifers Dacrydium, Dacrycarpus and the beech N. fusca, by creating much of the environmental variation to which these species responded. This study adds to our understanding of the effects of historical earthquakes in the relatively complex forests of north Westland, and further illustrates their importance in the Westland forest landscape as the major influential disturbance on forest pattern and history. These results also further develop the 'two-component' model used to describe conifer/angiosperm dynamics, by identifying qualitative differences in the impacts of different large, infrequent disturbances across an environmental gradient that allowed for coexistence of different species. In poorer drained areas, these forests may even be thought of as 'three-component' systems with conifers, beeches and hardwoods exhibiting key differences in their regeneration patterns after disturbances of different type and extent, and in their microsite preferences.

Research Papers, Lincoln University

The urban environment influences the way people live and shape their everyday lives, and microclimate sensitive design can enhance the use of urban streets and public spaces. Innovative approaches to urban microclimate design will become more important as the world’s population becomes ever more urban, and climate change generates more variability and extremes in urban microclimatic conditions. However, established methods of investigation based upon conventions drawn from building services research and framed by physiological concepts of thermal comfort may fail to capture the social dynamics of urban activity and their interrelationship with microclimate. This research investigates the relationship between microclimate and urban culture in Christchurch, New Zealand, based upon the concept of urban comfort. Urban comfort is defined as the socio-cultural (therefore collective) adaptation to microclimate due to satisfaction with the urban environment. It involves consideration of a combination of human thermal comfort requirements and adaptive comfort circumstances, preferences and strategies. A main methodological challenge was to investigate urban comfort in a city undergoing rapid physical change following a series of major earthquakes (2010-2011), and that also has a strongly seasonal climate which accentuates microclimatic variability. The field investigation had to be suitable for rapidly changing settings as buildings were demolished and rebuilt, and be able to capture data relevant to a cycle of seasons. These local circumstances meant that Christchurch was valuable as an example of a city facing rapid and unpredictable change. An interpretive, integrative, and adaptive research strategy that combined qualitative social science methods with biophysical measures was adopted. The results are based upon participant observation, 86 in-depth interviews with Christchurch residents, and microclimate data measurements. The interviews were carried out in a variety of urban settings including established urban settings (places sustaining relatively little damage) and emerging urban settings (those requiring rebuilding) during 2011-2013. Results of this research show that urban comfort depends on adaptive strategies which in turn depend on culture. Adaptive strategies identified through the data analysis show a strong connection between natural and built landscapes, combined with the regional outdoor culture, the Garden City identity and the connections between rural and urban landscapes. The results also highlight that thermal comfort is an important but insufficient indicator of good microclimate design, as social and cultural values are important influences on climate experience and adaptation. Interpretive research is needed to fully understand urban comfort and to provide urban microclimate design solutions to enhance the use of public open spaces in cities undergoing change.

Research papers, University of Canterbury Library

Buildings subject to earthquake shaking will tend to move not only horizontally but also rotate in plan. In-plan rotation is known as “building torsion” and it may occur for a variety of reasons, including stiffness and strength eccentricity and/or torsional effects from ground motions. Methods to consider torsion in structural design standards generally involve analysis of the structure in its elastic state. This is despite the fact that the structural elements can yield, thereby significantly altering the building response and the structural element demands. If demands become too large, the structure may collapse. While a number of studies have been conducted into the behavior of structures considering inelastic building torsion, there appears to be no consensus that one method is better than another and as a result, provisions within current design standards have not adopted recent proposals in the literature. However, the Canterbury Earthquakes Royal Commission recently made the recommendation that provisions to account for inelastic torsional response of buildings be introduced within New Zealand building standards. Consequently, this study examines how and to what extent the torsional response due to system eccentricity may affect the seismic performance of a building and considers what a simple design method should account for. It is concluded that new methods should be simple, be applicable to both the elastic and inelastic range of response, consider bidirectional excitation and include guidance for multi-story systems.

Research papers, University of Canterbury Library

On 22 February 2011, Canterbury and its largest city Christchurch experienced its second major earthquake within six months. The region is facing major economic and organisational challenges in the aftermath of these events. Approximately 25% of all buildings in the Christchurch CBD have been “red tagged” or deemed unsafe to enter. The New Zealand Treasury estimates that the combined cost of the February earthquake and the September earthquake is approximately NZ$15 billion[2]. This paper examines the national and regional economic climate prior to the event, discusses the immediate economic implications of this event, and the challenges and opportunities faced by organisations affected by this event. In order to facilitate recovery of the Christchurch area, organisations must adjust to a new norm; finding ways not only to continue functioning, but to grow in the months and years following these earthquakes. Some organisations relocated within days to areas that have been less affected by the earthquakes. Others are taking advantage of government subsidised aid packages to help retain their employees until they can make long-term decisions about the future of their organisation. This paper is framed as a “report from the field” in order to provide insight into the early recovery scenario as it applies to organisations affected by the February 2011 earthquake. It is intended both to inform and facilitate discussion about how organisations can and should pursue recovery in Canterbury, and how organisations can become more resilient in the face of the next crisis.

Research Papers, Lincoln University

An emerging water crisis is on the horizon and is poised to converge with several other impending problems in the 21st century. Future uncertainties such as climate change, peak oil and peak water are shifting the international focus from a business as usual approach to an emphasis on sustainable and resilient strategies that better meet these challenges. Cities are being reimagined in new ways that take a multidisciplinary approach, decompartmentalising functions and exploring ways in which urban systems can share resources and operate more like natural organisms. This study tested the landscape design implications of wastewater wetlands in the urban environment and evaluated their contribution to environmental sustainability, urban resilience and social development. Black and grey water streams were the central focus of this study and two types of wastewater wetlands, tidal flow (staged planning) and horizontal subsurface flow wetlands were tested through design investigations in the earthquake-affected city of Christchurch, New Zealand. These investigations found that the large area requirements of wastewater wetlands can be mitigated through landscape designs that enhance a matrix of open spaces and corridors in the city. Wastewater wetlands when combined with other urban and rural services such as food production, energy generation and irrigation can aid in making communities more resilient. Landscape theory suggests that the design of wastewater wetlands must meet cultural thresholds of beauty and that the inclusion of waste and ecologies in creatively designed landscapes can deepen our emotional connection to nature and ourselves.

Images, Alexander Turnbull Library

A man chats over the fence with a newcomer to the area who is digging a vegetable patch. The newcomer is wearing a red and black striped jersey, his dog wears a red and black dog-coat and there are red and black curtains in the windows of the house. The passer-by wonders where the newcomer has located to the Waikato from. The colours make it obvious that he is from Christchurch. Context - People moving away from Christchurch following the earthquake of 22 February 2011. Quantity: 1 digital cartoon(s).

Images, Alexander Turnbull Library

A passerby stops at an advertisement on the lawn outside a house which reads 'Sound commercial property - Christchurch $450,000' and comments to the owner that it 'seems a good buy'. The owner tells him that's 'the yearly rental'. Context - property and rental prices in Christchurch since the earthquakes of 4 September 2010 and 22 February 2011. Quantity: 1 digital cartoon(s).

Images, Alexander Turnbull Library

At top left is text reading 'Christchurch pupils return to school...' The teacher has written the words 'Nosey', 'Bob', and 'Double' on the blackboard and says to the children 'Our first test today... Sort these into Parkers we love and Parkers we don't'... Context - the correct answers would be that we hate 'nosey parkers' and 'double parkers' but that we love 'Bob Parker'. Bob Parker is the Mayor of Christchurch and is generally considered to have done a remarkably good job of demonstrating calm and cheerfulness after the two earthquakes of 4 September 2010 and 22 February 2011, as well as having been able to chose fitting words to express grief and despair at so much loss. Quantity: 1 digital cartoon(s).

Images, Alexander Turnbull Library

MP Jim Anderton who is standing for Mayor of Christchurch in the coming local body elections (9th October) stands up to his chest in a crack in the road waving a sign that reads 'Jim Anderton for mayor' and yelling "I'm still here!' Refers to the very high profile that his rival the standing mayor Bob Parker has enjoyed in the aftermath of the Christchurch earthquake of 4th September 2010. Jim Anderton has rather faded out of the limelight by comparison. Quantity: 1 digital cartoon(s).

Images, Alexander Turnbull Library

A woman chats over her garden wall to a passerby who is curious about a huge container-like structure labeled 'emergency kit' that has been built beside the house. She says that in the event of a natural disaster Harold wants to ensure that they will have enough provisions to see them through the Rugby World Cup. Refers to the Christchurch earthquake that occurred 4th September 2010. Quantity: 1 digital cartoon(s).

Images, Alexander Turnbull Library

PM John Key sits at a large desk in a very large chair looking disconcerted as a messenger says 'after your display in the charity match - John Wright wants you on standby for India. Context - The charity match for Christchurch played at the Basin reserve on Sunday 9 March 2011. The prime minister played along with actors Russell Crowe and James Nesbitt, who were opposing coaches with the match being refereed by Ian McKellen in Sunday's match starting at 4pm. Key will face an over from the Australian spin king during the innings break at the Basin, which Cricket Wellington expects could sell out as early as today. Quantity: 1 digital cartoon(s).

Images, Alexander Turnbull Library

A woman sits reading a newspaper with reports about the Japanese earthquake and the latest news on Christchurch post-earthquake. Her husband has just put a Jerry Lee Lewis record on the turntable and the song 'Whole lotta shakin' goin' on' is playing; he says Didn't I always say this guy was ahead of his time?' Context - The Christchurch earthquakes of September 4 2010 and February 22 2011 as well as the Japanese earthquake and tsunami of 11 March 2011. Quantity: 1 digital cartoon(s).

Images, Alexander Turnbull Library

Cartoon shows a mechanic asking his boss for a pay rise. Text reads 'Like the Christchurch Council CEO - I've also been working hard. Would I be cheeky to ask for a $68,000 pay rise?'. Context: Christchurch City Council Chief Executive Officer Tony Marryatt ended up turning down a pay rise of $68,000 following the outcry when the fact was made public. Quantity: 1 digital cartoon(s).

Images, Alexander Turnbull Library

Christ Church Cathedral, Christchurch, with spire being rebuilt after the 1901 earthquake. Photographer unidentified. The nave, tower and spire of Christchurch Cathedral was completed in 1881. Work on completeing the rest of the building began in 1900. In 1902 the transcepts were finished and work started on the chancel and apse. An earthquake in 1901 cracked the upper part of the spire in two places. In this photograph which dates from late 1902/1903 (see scaffolding beyond the transcept indicating work on chancel) the upper part of the spire has been removed by Messrs Graham and Greig in preparation for replacing this section with a copper covered wooden structure. The Cathedral was completed in 1904. (Information from "Vision and Reality; Christchurch Cathedral in the Square," Colin Brown, Christchurch, 2000 and "A Dream of Spires," Ian Lochhead, Canterbury University Press, 1999, page 153.) Preparation for erecting the scaffolding was reported in the Christchurch Star 15 January 1902. The cross was replaced on the top of the new copper covered wooden section of the spire on 29 June 1903. Source of descriptive information - Notes on file print. Source of title - Title supplied by Library Quantity: 1 b&w original negative(s). Physical Description: Glass negative

Images, Alexander Turnbull Library

Text reads 'What??... Is it another quake?.. No, it's just Gerry Brownlee rushing the CERA bill through'. The cartoon shows the huge back of Minister for Christchurch Recovery Gerry Brownlee moving energetically and forcefully to get the CERA bill past its third reading. Context - The bill establishes the Canterbury Earthquake Recovery Authority (Cera) and empowers it to lead reconstruction efforts in Christchurch. It gives Cera specific powers to get information from any source, to requisition and build on land and to carry out demolitions. It can also take over local authorities if they are not working effectively on recovery work. Quantity: 1 digital cartoon(s).