Using portfolio analysis to assess diverse agricultural landscapes under climate change: A case study in the Marlborough wine region
A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2024) Barry, Michelle
Farmers and growers are increasingly aware of climate change related risks for their operations as they observe a greater frequency in extreme weather events and changes in crop growth cycles. While reactive adaptation by farmers to climatic variability has always occurred, this may not be sufficient in the long term when anticipatory and planned adaptation is required, e.g., changes in cultivar or the development of new markets. Geographical and biological diversification of agricultural production systems has been proposed as a potential climate change adaptation strategy. Understanding how alternative crops, land-uses and management practices will perform under future climates and deliver to stakeholder goals is critical before extensive land-use and practice change occurs. Developing this understanding is difficult due to the high degree of uncertainty of future climatic conditions and the ability of commonly applied economic analysis tools to account for this deep uncertainty. To address these challenges, this PhD developed a stakeholder centred climate change adaptation process that utilises Portfolio Analysis to identify diversified vineyard portfolios and characterised their riskiness across a range of climate change scenarios. In developing this process, the study applied a mixed methods framework, integrating qualitative and quantitative approaches. These included a literature review, stakeholder mapping, focus groups, biophysical assessment and economic modelling, integrated in a case study on Marlborough Sauvignon Blanc.The research found that Portfolio Analysis can be effectively integrated with social and biophysical science to develop diversified vineyard portfolios that are more robust against a range of possible climate futures, helping to inform decision making in the context of deep uncertainty. To accelerate adoption, adaptation needs to be integrated into wider wine business and industry decision making and strategy development. Recognising that adaptation sits alongside existing ambitions and priorities, particularly around environmental sustainability, is also critical.