Research@Lincoln

Recent Submissions

  • ItemOpen Access
    Identification of the best viticultural areas by spatial optimisation. Application in New Zealand South Island in the context of climate change
    (The International Viticulture and Enology Society (IVES), 2024) Hamon, Baptiste; Thibault, Jeanne; Tissot, Cyril; Parker, Amber; Quénol, Hervé
    The global winegrowing sector is under pressure due to the effects of global climate change. This is particularly true for New Zealand, where the wine industry is limited to a few regions. This study focuses on the South Island of New Zealand. It uses the Multi-objective Optimisation for Agrosystems (MOA) model to (i) investigate how potential exposure to climate risks and phenological stages will evolve under climate change, (ii) assess the suitability of current vineyards for viticulture in the future, and (iii) investigate potential emerging areas favourable for viticulture. The results show that a significant shift in the phenological stages of veraison and ripeness can be expected in the future due to the warming of the South Island of New Zealand. The projected phenological stages advancement is around one week in the near term for both Shared-Socioeconomic Pathways studied (SSP2-4.5 and SSP5-8.5) and is more than three weeks and one month in long-term for SSP2–4.5 and SSP5-8.5 respectively. A regional to local increase in frost risk (Canterbury, Otago, and Southland) and a slight increase in disease risk (especially on the coast) are also projected in the future, while the South Island of New Zealand is not expected to be affected by heatwaves. The results show that Marlborough, New Zealand's most important winegrowing region, will continue to be one of the best areas for viticulture in the 21st century. On the other hand, new winegrowing opportunities are expected to emerge inland and southwards. Overall, this study contributes to the understanding of the impact of climate change on the New Zealand wine industry and emphasises the need to adapt to changing climate conditions. It also provides insights into the future suitability of vineyards and identifies potential expansion areas for the New Zealand viticulture sector.
  • ItemRestricted
    Cryopreservation of six Symbiodiniaceae genera and assessment of fatty acid profiles in response to increased salinity treatments
    (Springer Nature, 2022) Kihika, Joseph Kanyi; Wood, Susanna A; Rhodes, Lesley; Smith, Kirsty F; Miller, Matthew R; Pochon, Xavier; Thompson, Lucy; Butler, Juliette; Schattschneider, Jessica; Oakley, Clint; Ryan, Ken G
    Symbiodiniaceae are a diverse group of dinoflagellates, the majority of which are free-living and/or associated with a variety of protists and other invertebrate hosts. Maintenance of isolated cultures is labour-intensive and expensive, and cryopreservation provides an excellent avenue for their long-term storage. We aimed to cryopreserve 15 cultured isolates from six Symbiodiniaceae genera using dimethyl sulfoxide (DMSO) as the cryoprotectant agent (CPA). Under 15% DMSO, 10 isolates were successfully cryopreserved using either rapid freezing or controlled-rate freezing. Cultures that failed or had low survival, were subjected to (1) a reduction of CPA to 10%, or (2) increased salinity treatment before freezing. At 10% DMSO, three further isolates were successfully cryopreserved. At 15% DMSO there were high cell viabilities in Symbiodinium pilosum treated with 44 parts per thousand (ppt) and 54 ppt culture medium. An isolate of Fugacium sp. successfully cryopreserved after salinity treatments of 54 ppt and 64 ppt. Fatty acid (FA) analyses of S. pilosum after 54 ppt salinity treatment showed increased saturated FA levels, whereas Fugacium sp. had low poly-unsaturated FAs compared to normal salinity (34 ppt). Understanding the effects of salinity and roles of FAs in cryopreservation will help in developing protocols for these ecologically important taxa.
  • ItemOpen Access
    Impact of agricultural cooperative membership on household food security in Mchinji District, Malawi
    Mwalabu, Bertha; Kaitibie, Simeon; Lyne, Michael
    Despite being an agrarian economy, food insecurity and malnutrition remain major challenges in Malawi. Progress towards food security has been undermined by problems such as environmental degradation, lack of mechanisation, improper land management, insufficient and untimely extension services, and limited landholding, leading to low productivity among smallholders. Agricultural cooperatives can improve productivity by making agricultural inputs, extension advice, and modern farming technologies more accessible. Additionally, cooperatives can enhance smallholders’ income opportunities through collective marketing of agricultural produce to preferred markets. While smallholder cooperatives often fall short of meeting performance expectations, empirical studies in some developing countries provide evidence supporting the view that cooperative membership can improve food security among smallholders. However, no such study has been conducted in Malawi. This study aims to understand the impact of cooperative membership on household food security in rural areas of Malawi’s Mchinji district. Representative samples of cooperative member and non-member households were selected using probability-based sampling techniques. Primary data needed to estimate the impact of cooperative membership on household food security were collected using a structured questionnaire administered in-person to 475 household respondents. The impact of cooperative membership on household food security was estimated using propensity score matching and two-stage least squares (2SLS) regression with instrumental variables. These methods were chosen for their ability to account for selection bias and the effects of other determinants of food security. The findings bridge a gap in cooperative-food security literature and suggest a number of targeted policy interventions to address food insecurity in rural Malawi. The results will also serve as a reference for future research.
  • PublicationOpen Access
    Designing urban green spaces that enable mindfulness and nature connectedness : A dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Landscape Architecture at Lincoln University
    (Lincoln University, 2024) Saxman, Hanna-Mari
    This research brings together the interconnectedness of mindfulness and subjective connection with nature, their benefits to human wellbeing, and the design of urban green spaces. As populations are increasingly concentrating in cities, residents can experience more stress and become estranged from nature. The considerable amount of research on the benefits of mindfulness and nature connections is pointing a way to an opportunity for Landscape architects to positively affect human wellbeing through design. To empathise with a diverse group of visitors, this study considers the ephemerality of experiences and understanding the spaces first-hand using the Persona method, case studies and sensory mapping in four green spaces in Christchurch over two seasons. The results showed that public urban green spaces can be designed to simultaneously support and enable mindful activities and nature connectiveness, and that indeed features enabling one often also enable the other. The study revealed the importance of locating these spaces within public transport services and commute routes to create opportunities for accessing them. Utilising empathy was found to be an effective way to understand the user experiences and a valid method for the landscape architecture profession to understand the current settings as well as test design ideas on paper or at a site. Sensory maps were found to be a useful tool for post occupancy evaluations, site inventory, and site analysis to ensure senses are accounted for in design, and that the experience of people with different abilities are considered throughout the process.
  • ItemRestricted
    Calamities of Fresh Value Chains in developing economies: The case of the avocado value chain in Ethiopia
    (2024-10-23) Seba, Samuel Tigistu; Wilson, Mark; Bicknell, Kathryn; Radics, Robert; Chowdhury, Mesbahuddin; Koushan, Mona; Mollenkopf, Diane
    Ensuring availability and affordability are the most critical and pertinent requirements for Fresh Value chains (FVCs) to ensure food and nutritional security. On the other hand, securing adequate income is critical to ensuring economic development. However, studies indicate that FVCs in developing countries perform poorly, with persistent shortfalls in the availability of affordable fresh produce and very low incomes for producers and other actors. Literature suggests that the poor performance of FVCs in Ethiopia could result from a lack of investment by actors across all stages of the chains. A thorough literature review has identified four theories that can explain the apparent lack of investments in FVCs in developing countries. New Institutional Economics (NIE) theory asserts that the nature of transactions and characteristics of actors and exogenous changes in the general economy create uncertainty that brings about high transaction costs and inefficient institutions, leading to the likelihood of opportunism, lack of investment, and Pareto-suboptimal efficiency. Agency theory asserts that agents' opportunistic behaviours arise from information asymmetry and goal incongruence when two actors are required to collaborate in an economic system through transactions. These result in high levels of unmitigated state, effect and response uncertainty and the likelihood of opportunism, disincentivising investments in these mostly arm's length relationships. Post- Keynesian investment theory asserts that the availability and cost of different forms of finance (profit and credit) affect the level of investments. Systems Theory asserts that shortages of different types of capital are potential constraints to producing and marketing fresh produce in developing countries, implying the role of investments. This article presents empirical findings on the current performance of the Avocado Value Chain (AVC) in Ethiopia. It attempts to identify the underlying factors for the ongoing lack of investments by utilising a framework developed from the above mentioned theories. The research utilised the critical realist approach, Systems Dynamics Modelling (SDM) methodology, and a four-tiered research process to achieve the overall research objectives. The data was collected using the four tiers: an extensive literature review, direct observation of all value chain activities, in-depth interviews with more than 65 actors and stakeholders, and participatory Group Model Building (GMB) workshops. Data gathered were used to describe the attributes of each actor, their interactions, the structure of relationships, the transactions, the business environment they operate in and the resulting severe lack of investment in the AVC manifested through each actor's modus=operandi and the poor performance that follows.