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Item Green banking : an exploration from the perspectives of banks, and retail bank customers : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Banking at Massey University, Manawatu Campus, School of Economics and Finance, New Zealand. EMBARGOED UNTIL JULY 2027.(Massey University, 2024-11-11) Kalu Kapuge Dona, Lilani Randika KapugeThis study explores green banking adoption from the perspectives of banks, and retail bank customers. Our aim is to contribute to banks’ adoption of green banking. This is achieved by examining banks’ green practices and proposing a constructivist framework for banks to transform from conventional banking into green banking. As banks are driven by a profit motive, if banks’ environmental performance positively connects with attaining their profitability objectives, there may be a motivation to apply green banking practices. In Essay One, we examine the impact of banks’ green performance and disclosures on their financial, market, and risk performance. We employ Bloomberg’s environmental disclosure scores and Refinitiv’s environmental performance scores as proxies to measure banks’ green performance and disclosures. As an addition to ESG literature, we use Yale’s Environmental Performance Index (EPI) to examine the extent to which the home country’s environmental performance moderates the links between the impact of banks’ environmental performance and disclosures on their financial, market and risk performance. Data was drawn from 189 of the world’s largest banks for the period 2009 to 2019, and the analysis incorporates two-step system GMM models. To check the robustness of our results, we removed banks that are major financiers of fossil fuels and EU banks from the main sample. We find no evidence to support Bloomberg’s environmental disclosure scores or Refinitiv’s environmental performance scores impacting banks’ financial, market and risk performance. In addition, EPI does not moderate the links between the impact of banks’ environmental performance and disclosures on their financial, market and risk performance. The findings confirm that environmental performance and environmental disclosures do not matter to big banking players’ prosperity. Overall, this study establishes the need for a commonly agreed banking-industry-oriented environmental rating scale to measure banks’ green performance correctly to avoid misleading green-conscious stakeholders and identify banks’ true green efforts. In Essay Two, in response to the absence of an agreed or standard performance measurement mechanism for green banking, we develop a green banking scorecard (GBS) from a new perspective. First, we use the updated version of the Planetary Boundaries Theory (PBT) to broaden the green banking measurement scale. Second, we employ a Fossil Fuel Index (FI) to assess banks’ true commitments towards green banking, because banks are often criticised as major financiers of fossil fuels. Third, as a new addition to banks’ green performance measurement, we use Yale’s Environmental Performance Index (EPI) which brings international differences in measuring banks’ green performance into a common platform. We apply the GBS to 37 of the world's largest banks to measure their green performance. We find that European banks achieve higher green banking scores compared to Asian and American banks. In Essay Three, following Stakeholders' Theory, stakeholders’ positive behavioural change towards green banking is essential for banks to adopt green banking. Employing Behavioural Response Theory (BRT), we examined retail bank customers’ intention to adopt green banking in New Zealand using 254 online survey responses. To extend this study, we examine whether retail bank customers’ environmental knowledge moderates the association between attitude towards green banking and intention to adopt green banking. The study finds retail bank customers prefer green banking although some of them do not yet intend to adopt green banking. The findings confirm that environmental knowledge has a weak negative moderating effect on the association between attitude towards green banking and intention to adopt green banking. The responses from this study indicate there are specific factors that affect and limit retail bank customers’ intentions to adopt green banking. In summary, this study concludes environmental disclosure scores, or environmental performance scores do not impact banks’ financial, market and risk performance. We proposed a green banking scorecard (GBS) from a new perspective to measure banks’ green performance and we find that European banks achieve higher green banking scores compared to Asian and American banks. Finally, the study finds retail bank customers also prefer green banking and intend to adopt green banking.Item An evaluation of greenhouse gas emissions reduction potential of plantain (Plantago lanceolata L.) in pastoral dairy production systems : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Agriculture Systems Management at Massey University, Manawatu, New Zealand(Massey University, 2025-05-16) Sivanandarajah, KomahanThere is increasing interest in the ability of plantain (PL) to reduce nitrogen (N) leaching losses and mitigate nitrous oxide (N₂O) emissions, while maintaining milk and pasture production. While PL’s role in lowering urinary N concentration is well established, the results regarding the effect of PL on N₂O emissions have been inconsistent. Furthermore, evidence has shown that cows fed pure PL produce less methane (CH₄) emissions compared to those fed ryegrass. However, whether this CH₄ reduction can be achieved with PL in mixed pasture, along with a clear understanding of the mechanism(s) behind those reductions, are still to be determined. This thesis evaluates PL’s potential to mitigate CH₄ and N₂O emissions through a series of in vitro and a field experiment, focusing on mixed pastures with moderate PL levels. When pastures, either a conventional ryegrass-white clover (RWC) or an RWC mix containing ~40% of PL (PLM), were collected during different seasons and tested in an in vitro rumen batch culture system, differences in their chemical composition led to significant differences in CH₄ and rumen ammonia (NH₃) production. Compared to RWC, PLM had lower fibre (neutral detergent fibre and acid detergent fibre), higher lignin, more fermentable carbohydrates (non-structural carbohydrates), and plant secondary metabolites (PSM, acteoside and aucubin) detected only in PLM, while maintaining similar digestibility and crude protein (CP) levels. Consequently, PLM produced up to 27% less net NH₃ in spring, up to 19% less CH₄ in summer, and 17% less net NH₃ in autumn compared to RWC (p<0.05) in vitro. Plant secondary metabolites found in PL, have been associated with reducing N losses from grazed pastures. However, their influence on enteric CH₄ emissions remains unexplored. Additionally, the dose-response relationship between CH₄ and NH₃ production at different concentrations of PSM needs to be established. To address this, purified compounds (>99% purity) of acteoside and aucubin were incubated with perennial ryegrass (RG) as a basal substrate, and gas and CH₄ production were measured in vitro. The addition of acteoside to RG increased gas production (GP) by up to 12%, with a similar quantity of CH₄ production, but a 5–15% lower proportion of CH₄ in gas (%CH₄), compared to the control. Aucubin addition resulted in a longer lag phase for GP and CH₄ production. On addition of aucubin, it took up to 15% more time to reach the halftime (T1/2) GP and up to 20% longer to reach the T1/2 CH₄ production. The combined treatments of acteoside and aucubin produced up to 13% greater GP with similar CH₄ production and reduced %CH₄ by around 9%. These reductions are attributed to the modification of the hydrogen utilisation pathway (less hydrogen to produce CH₄) affected by acteoside. Aucubin reduced rumen net NH₃ production by up to 46%, with a similar reduction observed when acteoside was combined with aucubin. These reductions are attributed to the possible antimicrobial activity of aucubin. These results suggest that PL influences rumen fermentation in vitro, resulting in lower CH₄ and NH₃ production. Since higher rumen NH₃ correlates with greater urinary N excretion into the environment, reducing NH₃ levels in the rumen is advantageous. Previous studies have shown that N₂O emissions from PL pastures may be reduced due to smaller N concentrations in urine and/or biological nitrification inhibition (BNI) activity. In this study, urine collected from cows fed diets containing 0% PL, ~20% PL, and diluted urine from PL-fed cows, was applied to pastures containing 0% PL, 30% PL, and 40% PL during spring. The N₂O emissions were measured over 55 days. Results indicated a trend toward lower N₂O emissions as assessed using the emission factor (EF₃) metric, with increasing PL content (p<0.09), with an average reduction of around 28% for pastures containing 30–40% PL compared to RWC pastures (p=0.03). This reduction in N₂O emissions from PL pastures was attributed to BNI activity rather than differences in urine-N concentrations per se. These results enhance our understanding of PL’s role in mitigating environmental impacts from grazing ruminants in temperate systems. This thesis concludes that medium PL pastures (30–40% PL) exhibit significant environmental benefits compared to RWC pastures in vitro, with reductions in CH₄ and rumen NH₃ influenced by PSM in PL and the seasonal variability in chemical composition. Moreover, under conditions conducive to higher N₂O emissions (in spring), maintaining 30–40% PL in the pasture could reduce N₂O emissions more effectively than excluding PL.Item Enhancing grassland nitrogen estimation : a multiscale approach through optical reflectance spectroscopy and hybrid modeling techniques : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Earth Science at Massey University, Palmerston North, New Zealand(Massey University, 2025-01-21) Dehghan-Shoar, Mohammad HossainOptical remote sensing technology has emerged as a powerful tool for assessing vegetation characteristics, particularly nitrogen (N) concentration (N%) in heterogeneous grasslands. Accurate estimation of N% is crucial for farmers, as it directly influences grassland productivity and plays a key role in sustainable land management. Accurate N assessments optimize fertilizer use, boosting productivity, lowering costs, and enhancing environmental modeling to address impacts such as N leaching and greenhouse gas emissions. Despite significant progress, challenges and knowledge gaps remain, highlighting the need for continued research to fully harness remote sensing’s potential in agricultural management and its impact on livestock productivity. This thesis aims to advance the accurate estimation of grassland N% by integrating physically-based, empirical-statistical, and hybrid models using optical reflectance spectroscopy data. The research focuses on three primary objectives: 1. To estimate N% in grasslands using optical reflectance spectroscopy, data will be collected across multiple scales, including ground-, leaf-, canopy-, and satellite-scale observations. 2. To improve the universality and adaptability of grassland N% models through a hybrid approach that combines data from various optical sensors across multiple scales. 3. To account for and quantify uncertainties in grassland N% prediction models. The thesis addresses the challenge of uncertainty by conducting a comprehensive analysis of its sources and developing methods, such as Physically Informed Neural Networks (PINN), to account for them. Key strategies include data fusion techniques for integrating diverse data sources and improving atmospheric correction methods. A unified methodology combining empirical-statistical and physically-based approaches is proposed to enhance generalization. Machine learning algorithms play a pivotal role in feature selection and optimization, further improving model accuracy and transferability. The developed methods undergo evaluation using independent validation data collected from heterogeneous grasslands across different periods and locations. Results demonstrate that integrating physically-based and empirical-statistical approaches significantly improves model accuracy and transferability, providing a deeper understanding of the factors influencing vegetation traits. This thesis highlights the importance of advanced techniques, including machine learning, deep learning algorithms, Radiative Transfer Models (RTM), and data fusion methods, for precisely characterizing vegetation traits, contributing to more sustainable and efficient grassland management practices.Item Model-based packaging design for minimising environmental impact of horticultural packaging systems : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Food Technology at Massey University, New Zealand. EMBARGOED until 13 November 2026.(Massey University , 2024) Lozano, RaquelPackaging systems are instrumental in delivering high-quality food products to consumers. Food industries grapple with losses throughout the supply chain, resulting in both product and monetary setbacks. When considering the embodied resources in food production, including raw materials, energy, water, and emissions, minimising losses in any stage of the food supply chain is crucial. The New Zealand kiwifruit industry faces several constraints which include short harvest seasons, considerable distance to markets and year-round consumer demand. Packaging and storage plays a role in overcoming these factors by preventing undesirable quality loss traits. Establishing the link between packaging systems, supply chain conditions, and kiwifruit quality (specifically shrivel) provides a basis for evaluating the trade-off between over-packaging and excessing fruit loss. In this thesis, an integrated-mathematical model was developed to aid decision-making in for kiwifruit packaging, aiming to minimise the overall environmental impact throughout the kiwifruit supply chains from packhouse to purchase. This integrated-mathematical model facilitates exploratory analysis of both current and future supply chains and packaging systems. Four models were integrated: mass balance, moisture loss prediction, shrivel loss prediction and an optimisation engine. The mass balance model captured the kiwifruit and packaging masses and associated environmental impacts within kiwifruit supply chains. This model, applicable to any environmental metric, was developed to facilitate the prediction of kiwifruit losses. To validate its accuracy, the framework was applied in assessment examples, comparing its performance against existing research for kiwifruit supply chains. The absolute difference between predicted and actual emissions of CO2eq were less than 1% of the actual mean emissions at different stages of the supply chain. The moisture loss model was used to estimate kiwifruit weight loss both on a packaging unit and individual kiwifruit basis. The model demonstrated close agreement between weight loss predictions and experimental data for average packaging weight loss scenarios. Further refinement is needed to predict individual kiwifruit weight loss, specifically considering the impacts of packaging features on internal packaging water vapour distributions. The shrivel prediction model revealed that predicting kiwifruit losses due to shrivel posed challenges, primarily due to the current knowledge gap regarding the development of shrivel in kiwifruit under storage conditions. While increases in shrivel has been correlated to weight loss in existing literature, the reference state (at orchard, packhouse etc.) is arbitrary. Ideally shrivel would be related to an intrinsic property that could be measured at any point in time without requiring knowledge of this prior history of the fruit. The prediction of losses based on a non-relative starting point represents a knowledge gap addressed in this work, with potential improvements identified for future model iterations. This phase of the model development heavily relied on data collection to establish a mathematical relationship between weight loss and shrivel. The moisture loss and shrivel model served as the foundation for the development of an optimisation engine, enabling the identification of the optimal use of packaging. This model sought a balance between packaging mass and kiwifruit losses, employing various environmental impact categories as performance metrics. The success of this approach was evident as optimal packaging points were identified across (i) different packaging materials, (ii) different packaging materials and formats and (iii) different environmental impact categories. It was found that each optimum point for materials were unique to the ambient conditions of the supply chain, packaging format and material. This work revealed trade-offs between the environmental impact of the packaging material and amount of kiwifruit loss, numerically demonstrating what so far has only been presented as a theoretical concept in other research. Then, this integrated-model was applied to a range of real-life supply chain scenarios showcasing its versatility in addressing possible questions such as ‘what if ?’, ‘can we ?’ and ‘when can we ?. The application of the model to real-life scenarios demonstrated its utility for decision-making with respect to packaging materials and formats. This model is poised to offer crucial support for future packaging materials and supply chains. The limitation of this model lies in fruit loss predictions. To further model applicability, there remains further investigation of hypotheses developed during shrivel model development to refine the kiwifruit loss model. There also remains the opportunity to integrate more prediction models that account for the impact of packaging on other drivers of fruit loss, such as ethylene concentrations within the pack. While the integrated model developed in this thesis has some limitations in accurately predicting kiwifruit losses, this study highlights the significance of linking packaging performance and kiwifruit quality when evaluating environmental impacts. Although kiwifruit served as the focus in this work, the model created here paves the way for exploring the application of optimised packaging systems for other food commodities.Item Evaluating woodchip bioreactors for mitigating drainage nitrate levels from a municipal wastewater land treatment site : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Environmental Sciences at Massey University, Palmerston North, New Zealand(Massey University, 2024-09-23) Romero Ramírez, Stefanía YaninaWoodchips bioreactors are a well-established end-of-drain treatment technology that has been widely used to reduce nitrate (NO₃-) from agricultural drainage water. However, their application to municipal wastewater land treatment sites remains less explored, despite potential advantages. In New Zealand, land application of pre-treated wastewater is a growing practice to mitigate excessive nutrient discharges to the aquatic environment. Land treatment can prove effective when operated correctly, but challenges arise when large volumes of wastewater, and small areas available for irrigation, necessitate high application rates, which can result in NO₃- enrichment of drainage water. The Levin Wastewater Land Treatment Site (LWLTS) is an example of where relatively high annual volumes of municipal wastewater are irrigated over an under-sized application area, resulting in high application depths (4667 mm/year). Consequently, surface drains and shallow groundwater transfer NO₃- to the Waiwiri Stream continually all year. In order to reduce the impact of the LWLTS on the water quality of the Waiwiri Stream, one of its resource consent requirements involves reducing the NO₃- levels in the Waiwiri Stream, downstream from the site. The objective of this thesis was to evaluate the potential use of woodchip bioreactors for reducing NO₃- concentrations in drainage water from LWLTS, including an assessment of the ability of soluble C dosing to enhance NO₃- removal. Initial experiments used small-scale column woodchips bioreactors, which simulated similar water temperatures and NO₃- concentrations to those at the LWLTS. The effect of different water hydraulic retention times (HRT) and the use of dosing with two soluble C sources, liquid sugar, and ethanol, were assessed. Under warm temperature conditions, the column bioreactors achieved 99% NO₃- removal efficiency with a 10-hour HRT. In contrast, under cool water temperatures at the same HRT, the NO₃- removal efficiency decreased to 31%. Soluble C dosing was an effective strategy for enhancing NO₃- removal, with the choice of C source proving to be crucial. Ethanol demonstrated to be more efficient than liquid sugar. Additionally, it was determined that dosing with ethanol at a C:N dosing rate of 1.5:1 achieved high removal efficiencies of 77% under warm conditions and at a 3.3-hour HRT, and 82% under cool conditions and at a 10-hour HRT. Based on the results of the column bioreactor study, the performance of pilot-scale woodchip bioreactors at reducing NO₃- levels in drainage water were evaluated at the LWLTS under field conditions. These experiments involved quantifying the effects of different HRTs and dosing with ethanol at different C:N ratios. Operating the bioreactors, at a 10-hour HRT achieved average NO₃- removal efficiencies of 43% and 59% during the cool and warm seasons, respectively. While, at a 20-hour HRT, the removal efficiencies were 69% and 85%, respectively. The variations in NO₃- removal efficiency between both seasons demonstrated that during the cool season the bioreactors were on average about one-third less effective. When bioreactors, operating at 6.6-hour HRT in cool conditions, were dosed with ethanol at a C:N ratio of 0.75:1, the NO₃- removal efficiency improved from 24% to 93%. This result demonstrates that under field conditions ethanol dosing proved to be a higher effective strategy for enhancing the performance of woodchip bioreactors, particularly during cool periods. Based on the findings of the pilot-scale bioreactors, two woodchip bioreactor designs were proposed for the LWLTS: a non-dosed woodchip bioreactor of 645 m³ operating at a long HRT (20 hours), and an ethanol-dosed woodchip bioreactor of 197 m³ operating at a short HRT (6.6 hours). The two proposed designs provide contrasting approaches, although both are expected to achieve the same annual NO₃- load removal (1174 kg N/year) and have similar annualised NO₃- removal costs ($6.90 and $6.50/kg N, respectively). In the long term, it is expected that the NO₃- removal of the larger non-dosed bioreactor will decline at a faster rate compared to the ethanol-dosed bioreactor due to relying solely of woodchips as the C source. However, it would be less susceptible to the risk of bioclogging and has greater capacity to increase NO₃- removal. In addition, ethanol dosing could be introduced to the larger non-dosed bioreactor in the future, when a decline in NO₃- removal efficiency is observed. Therefore, the overall flexibility of the larger bioreactor design is an advantage but comes with higher initial set-up cost. The results of this research demonstrate that woodchips bioreactors are effective treatment methods for mitigating drain water NO₃- levels at a municipal wastewater land application site. Additionally, C dosing using ethanol proved to be a promising cost-effective alternative to enhance bioreactor performance, allowing the use of relatively short HRTs, especially during cool conditions. This increases the daily volume of water that can be effectively treated.Item Thin film electrochemical sensor for water quality monitoring : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Engineering, Massey University, Auckland, New Zealand(Massey University, 2023-12-11) Lal, KartikayFreshwater is the most precious natural resource, essential for supporting life. Aquatic ecosystems flourish in freshwater sources, and many regions around the world depend on aquatic food sources, such as fish. Nitrogen and phosphorous are the two nutrients, in particular, that are essential for growth of aquatic plants and algae. However, with rising population and anthropogenic activities, excessive amounts of such nutrients enter our waterways through various natural processes, thereby degrading the quality of freshwater sources. Elevated levels of nitrate-nitrogen content, in particular, lead to consequences for both aquatic life as well as human health, which has been a cause for concern for many decades. As recommended by the World Health Organization, the maximum permissible nitrate level in water is 11.3 mg/L. These levels are often exceeded in coastal areas or freshwater bodies that are close to agricultural land. Therefore, it is essential to monitor nitrate levels in freshwater sources in real-time, which can be achieved by employing detection methods commonly used to detect ionic content in water. Hence, a comprehensive review was carried out on various field-deployable electrochemical and optical detection methods that could be employed for in-situ detection of nitrate ions in water. The primary focus was on electrochemical methods that could be integrated with low-cost planar electrodes to achieve targeted detection of nitrate ions in water. Designing resilient sensors for real-time monitoring of water quality is a challenging task due to the harsh environment to which they are subjected. There is a significant need for sensors with attributes such as repeatability, sensitivity, low-cost, and selectivity. These attributes were first explored by evaluating the performance of silver and copper materials on three distinct geometric patterns of electrodes. The experiments produced promising results with interdigitated pattern of copper electrodes that were successful in detecting 0.1-0.5 mg/L of nitrate ions in deionised water. The interdigitated geometric pattern of electrodes were further analyzed in four distinct materials namely, silver, gold, copper, and tin with real-world freshwater samples that were collected from three different freshwater bodies. The water samples were used to synthesize varying concentrations of nitrate ions. The results showed tin electrodes performed better over other materials for nitrate concentrations from 0.1-1 mg/L in complex matrix of real-world sample. The nitrate sensor eventually needs to be deployed in freshwater bodies, hence a real-time water quality monitoring system was also built that incorporated sensors to monitor five basic water quality parameters with the aim to monitor and study the quality of water around the local area.Item Crohn's Disease and environmental factors in the New Zealand context : a thesis presented in partial fulfilment of the requirements for the degree of Doctoral of Philosophy in Nutritional Science at Massey University, Manawatū, New Zealand(Massey University, 2023) Morton, HannahBackground: Inflammatory bowel disease (IBD), consisting of Crohn’s disease (CD) and ulcerative colitis (UC), are lesser-known chronic diseases of the gastrointestinal tract. The causes of IBD are unknown, although research indicates an interplay of genetic, immunological, and environmental factors. The incidence and prevalence of CD in New Zealand (NZ) are among the highest worldwide, and unlike many other Western countries, evidence suggests the incidence rate is still increasing. Objective: The objective was to investigate the involvement of environmental factors in the aetiology, pathogenesis, and symptomatology of CD in NZ. Specifically, pathogenic bacterium Mycobacterium avium subspecies paratuberculosis (MAP), vitamin D, diet, and urbanisation. Methods: Patients with IBD and controls from around NZ completed a questionnaire on environmental factor exposure. Foods implicated in symptom triggering or exacerbation, the possible mechanism(s) involved, and whether vitamin D can confer protection, were investigated using an in vitro digestion method and in vitro model of the intestinal barrier. Serum vitamin D concentrations were measured and compared in patients and controls in order to explore a possible association between vitamin D and IBD. Lastly, the incidence and prevalence of IBD in the Manawatū region was determined, and the urban and rural incidence were compared. Results: Questionnaire derived data showed significant associations between CD and exposure to rural sources of microorganisms, and a major urban birthplace (≥100,000 residents), while rainwater for drinking and cooking during childhood was protective. No associations were observed between CD and MAP exposure. Over 50% of patients implicated dietary elements in symptom onset and/or exacerbation. The in vitro investigation findings suggest this may result from tight junction damage. Vitamin D concentrations did not differ between patients and controls, however, were significantly lower in CD patients that reported recent disease activity. In the Manawatū region, the mean annual incidence and 2013-point prevalence of CD were 17.7 and 250.4 per 100,000, respectively, and urban residence at diagnosis was associated with a six-fold greater IBD incidence compared to rural residence. Conclusions: The findings demonstrate that vitamin D, diet, and urbanisation are involved in CD. A greater understanding of environmental factors, especially modifiable factors, could provide opportunities for reducing CD risk, managing symptoms, or slowing disease progression.Item Three essays on corporate finance studies in China : a thesis presented in fulfilment of the requirements for the degree of Doctor of Philosophy in Finance at Massey University, Palmerston North, New Zealand(Massey University, 2023-11-13) Yue, ShuaiThis thesis investigates three aspects of listed firms in the Chinese market. The first essay in the thesis examines the impact of state ownership on firm performance using hand collected ownership data of firms with state-private mixed ownership structures. We find a U-shaped relationship between state ownership and firm performance. At lower levels, state ownership has a negative association with firm performance, but beyond a certain threshold (e.g., 55% for ROA and 44% for Tobin's Q), state ownership becomes positively associated with firm performance. This finding indicates a trade-off between the negative effects of grabbing hand and the monitoring benefits of state owners. In addition, the introduction of strategic investors moderates the influence of state ownership on firm performance. The results show that the U-shaped impact of state ownership on firm performance diminishes after the introduction of strategic investors, implying that strategic investors may mitigate the underperformance observed around the threshold state ownership levels. The second essay focuses on the corporate information environment. It investigates the behaviour of firms with politically connected executives regarding information disclosure when subject to government inspection influences. China initiated the central environmental protection inspection in 2016. We find that while firms with politically connected executives generally exhibit lower stock price crash risk, these politically connected firms are more prone to crash risk when subject to inspection influences than firms without political connections. Further, we examine whether the inspection effect on crash risk varies based on the type of political connections developed by executives, namely achieved and ascribed political connections. Our results show that firms with executives having achieved political connections are related to higher crash risk when under government inspection influences, but no significant impact is observed for firms with executives having ascribed political connections. The final essay examines the influence of firms’ exposure to economic policy uncertainty (EPU) on environmental investment and investigates whether firm size plays a significant role in this relationship. We find that although small firms are generally associated with lower levels of environmental investment compared to large firms, there is a positive association between small firms’ EPU exposure and environmental investment, indicating that small firms are more inclined to invest in environmental initiatives when facing higher EPU exposure.Item Characterisation and potential optimisation of seepage wetlands for nitrate mitigation in New Zealand hill country : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Soil Science, Massey University, School of Agriculture and Environment, Palmerston North, New Zealand(Massey University, 2023) Sanwar, SuhaDiffuse nitrate (NO₃⁻) loss to pastoral waterways in hill country headwater catchments is a water quality concern in many countries with pasture-dependent economies, including New Zealand (NZ). Sheep and beef farming is the dominant land use in NZ hill country which are often located in headwater catchments. As these primary industries strive toward production growth to meet global demand for meat exports, this agricultural intensification will introduce more NO₃⁻ to its waterways. This contrasts with the recently enacted National Policy Statement for Freshwater Management 2020 (NPS-FM) which recognises the significance and calls for the protection of small wetlands in recognition of their ecosystem services including nutrient regulation, water quality improvement as well as associated social well-being. Nitrate mitigation in low-order streams in pastoral headwater catchments are important due to their proportionally large catchment coverage and major contribution to the national NO₃⁻ load to NZ rivers. Seepage wetlands in hill country landscapes can be a N-sink and, therefore, is a potentially cost-effective and natural NO₃⁻-mitigation tool for improved water quality from the pastoral headwater catchments. Seepage wetlands are features that occur along low-order streams in the low gradient of hill country landscapes. Their organic matter-rich sediment, saturated conditions and locations at the convergence of surface and subsurface NO₃⁻ rich flow pathways make seepage wetlands a unique landscape feature in terms of NO₃⁻ reduction via denitrification processes. However, denitrification is spatially and temporally variable as the process is influenced by the wetland sediment and hydrological properties. Several studies have demonstrated that seepage wetlands can be a potential NO₃⁻ sink and have quantified high sediment denitrification capacities in individual wetlands. However, variations in sediment and denitrification properties across a range of wetlands and a comprehensive study of seepage wetland hydrological characteristics that influence NO₃⁻ attenuation have not been undertaken, particularly in pastoral hill country landscapes in NZ. This thesis has examined the spatial variabilities of seepage wetland denitrification and the denitrification-influencing sediment properties across four hill country seepage wetlands within the Horizons Regional Council administrative boundary in NZ. The spatial gradients of sediment properties were examined vertically (at 15 cm depth intervals) and horizontally (within- and between- wetlands) in seepage wetland sites. Sediment physicochemical (water content (WC), pH, Eh) and chemical properties (dissolved organic carbon (DOC), NO₃⁻, NH⁴⁺, %total carbon or %TC, %total nitrogen or %TN, C:N, dissolved Fe²⁺ and dissolved Mn²⁺) and sediment denitrification enzyme activity (DEA), that represents sediment denitrification capacity, were quantified. The DEA values were highest at the surface depths across all wetland sites. Based on the wide range (560-5371 µg N₂O-N kg⁻¹ DS h⁻¹) and distinctive surface DEA values, the seepage wetland study sites were categorised into high-performing H-DEA (>3000 µg N₂O-N kg⁻¹ DS h⁻¹) and comparatively low-performing L-DEA (<1000 µg N₂O-N kg⁻¹ DS h⁻¹) sites. The H-DEA sites measured 7 to 10 times higher surface DEA values compared to the L-DEA sites. Spatial variability of denitrification in seepage wetlands was mainly driven by sediment WC, NO₃⁻, %TC, %TN, C:N, dissolved Fe²⁺ and dissolved Mn²⁺ (p≤0.05). The H-DEA site measured high WC (78%) which was above the threshold for denitrification and high sediment NO₃⁻ (15.9-18.5 mg NO₃⁻N/kg DS), in contrast to the L-DEA sites (WC 39.8-37.4%, 2.5-3.97 mg NO₃⁻N/kg DS). The heterogeneity of WC explained the heterogeneous distribution of DEA within the individual L-DEA sites. The sediment properties accounted for only 58-73% of the overall spatial variability in DEA, suggesting that additional wetland characteristics such as wetland hydrology, could have an important influence on denitrification in seepage wetlands. The seepage wetland hydrology and associated NO₃⁻ removal were characterised in detail at one of the L-DEA sites located on Tuapaka farm. During the hydrological characterisation, streamflow discharge and water quality were monitored at inflow and outflow for a 2-year period (June 2019-May 2021). Shallow groundwater quality was monitored at the 0.5, 1 and 1.5 m depths at the inflow, midflow and outflow positions in the wetland for a 1.5-year period (November 2019-May 2021). The seepage wetlands site demonstrated a stream inflow-dominated hydrology (83-87%) with small seepage contributions (8-14%) to the seepage wetland hydrology. Precipitation was found to be the major hydrological and associated NO₃⁻ removal (means attenuation) driver in the seepage wetland site. The seepage wetland was found an overall NO₃⁻ sink that on an average removed 23% of the annual NO₃⁻ inflow. Compared to the stream inflow (<0.03 mg NO₃⁻N/L), higher shallow groundwater NO₃⁻ concentrations (<0.11 mg NO₃⁻N/L) suggests that seepage is potentially an important NO₃⁻ source in these wetlands. High flow conditions, high winter precipitation and direct grazing during low flow periods are potentially major NO₃⁻ loss hot moments. In contrast, initial rapid infiltration at the onset of high precipitation events in early winter and spring and dissipated flow conditions highlighted opportunities for NO₃⁻ attenuation in the wetland and were identified as major NO₃⁻ removal hot moments. An overall dissipated flow condition driven by seasonally equivalent precipitation (22% of annual precipitation in winter) facilitated considerably higher annual NO₃⁻ removal of 40.8% (2.78 kg NO₃⁻N) in the wetland in year 2, in contrast to very low NO₃⁻ removal (0.3%, ~0.02 kg NO₃⁻N) under an erratic annual precipitation distribution (38% of annual precipitation in winter) in year 1. These findings suggest there is scope to improve NO₃⁻ removal by optimising flow conditions to slow flow in seepage wetlands to minimise NO₃⁻ loss during NO₃⁻ loss hot moments. In a follow-up laboratory-scale seepage wetland intact sediment column experiment, the effectiveness of diffuse flow, via subsurface outflow, was investigated for the optimisation of the wetland NO₃⁻ removal. During the experiment, the flow intervention altered the NO₃⁻ reduction-constraints observed in the preceding hydrological study and facilitated anaerobic conditions conducive to denitrification to capitalise on the sediment denitrification capacity, which was quantified during the preceding seepage wetland sediment characterisation study. The flow intervention involved vertical downwelling of NO₃⁻ rich (5 mg NO₃⁻N/L) pastoral surface runoff and subsequent horizontal discharge through a subsurface sediment column depth of 15 cm depth, collected from the Tuapaka seepage wetland site. The effectiveness of the subsurface drainage intervention for NO₃⁻ removal was assessed by monitoring the subsurface outflow water quality. The study showed that flow intervention achieved 50-96% NO₃⁻ removal from NO₃⁻ rich surface runoff. Based on the observations from the column study, two separate optimal operational HRTs of 2 and 13 hr are recommended to achieve large NO₃⁻ removal (50% from NO₃⁻ input of 5 mg NO₃⁻N/L) in a short period of time and large reduction in NO₃⁻ concentration at the outflow (<0.15 mg NO₃⁻N/L), respectively. The reasonably short period of HRT for such high NO₃⁻ removal efficiency (50-96%) supports the potential for the application of subsurface outflow intervention as a practical in-situ NO₃⁻ mitigation strategy, which warrants further research. This study also acknowledges the associated technical limitations of translating the laboratory-based findings to the field scale and recommends future studies to overcome these research limitations including high sediment compressions during intact sediment column samplings from the field, for example. The thesis not only demonstrates a flow intervention strategy to improve NO₃⁻ mitigation via flow regulation in seepage wetlands, but also guides future management by identifying the potential seepage wetland hot spots in the landscape (chapter 3) and the NO₃⁻ removal hot moments in the wetlands (chapter 4) and also by recommending necessary HRTs for flow intervention (chapter 5). In summary, this thesis has generated a robust dataset that improves our understanding of seepage wetland characteristics and their influences on NO₃⁻ removal at spatial and temporal scales. From an application perspective, this research provides new knowledge as to ‘where’, ‘when’ and ‘how’ seepage wetlands can be targeted to enhance their role in NO₃⁻ mitigations in hill country landscapes. This information has the potential to accelerate the integration of seepage wetlands into the toolbox of NO₃⁻ management strategies that could be used at a farm scale to improve water quality leaving NZ pastoral headwater catchments.Item Use of New Zealand native browse shrubs on sheep and beef hill country farms : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science at the School of Agriculture and Environment, Massey University, Palmerston North, Manawatū, New Zealand(Massey University, 2023) Wangui, James ChegeSheep and beef cattle farming on hill country through the historic clearing of native vegetation for pasture has caused biodiversity loss and increased the risk of soil erosion. Exotic tree species such as poplar and radiata pine can be used to control erosion, but there is current interest in using native plants on the hill country for indigenous biodiversity restoration in addition to erosion control. However, there is limited information on the forage value, biomass, carbon stock, and potential economic impacts of native plants compared to exotics species. This thesis was aimed to address the lack of information available on native shrubs and their comparison to exotics trees and shrubs. The forage feeding value results revealed that native shrubs had consistent nutritional composition across seasons, higher metabolizable energy, and lower crude protein than the exotic shrub Salix schwerinii (Kinuyanagi). Findings on in vitro fermentation characteristics showed that native shrubs were highly digestible, yielded higher volatile fatty acids, microbial proteins, and greenhouse gases than S. schwerinii. Estimation of biomass revealed that the native shrubs were similar in aboveground biomass accumulation, but differed in allocation to foliage, branch, and stem. Melicytus ramiflorus (Mahoe) had lower foliage biomass while Coprosma robusta (Karamū) had lower branch biomass, among the evaluated shrubs. Estimated carbon stock accumulation was higher for Pittosporum crassifolium (Karo) due to a greater woodier portion (branch and stem) than M. ramiflorus and C. robusta but lower than exotic trees. The data from the native shrub studies was used in the bioeconomic model and showed that planting native shrubs or radiata pine on steep slopes equal to 10% of the farm area would reduce farm feed supply. This reduction would result in a decrease in sheep flock size and sheep flock net cashflow, particularly with higher planting rates and with of radiata pine. While radiata pine had a surplus overall farm net cashflow, native shrubs had negative cashflow due to high seedling costs and low carbon income, making their use on the farm currently unprofitable at the modelled prices. The study's findings suggest that replacing exotic trees with native shrubs can provide high-quality summer browse for livestock. The decision to plant native shrubs on steep hill country slopes would depend on the farmer’s financial situation and interest in biodiversity conservation and profits. However, reducing planting costs and increasing the carbon price would be necessary to make investing in native shrubs profitable and more attractive to farmers.
