title: Gendered geographies of resistance, resilience and reworking in Aotearoa feminist geography scholarship

authors: Adams-Hutcheson, Gail

abstract: Aotearoa New Zealand feminist geographies involve alliances of connected and vibrant researchers who pay close attention to the politics of knowledge production, power, intersectionality and decolonisation. Safe spaces to speak and write together have been nurtured over time ‘down under’ due to a collective politics of care and mentoring. This special issue demonstrates the strength of collective thinking on resistance, resilience and reworking contemporary geographical practice in Aotearoa. The four empirically based and theoretically informed articles develop new thinking about resistance to colonialism, patriarchy, racism, metricisation and oppression. These critical articles contribute to feminist geographical knowledges both locally and globally.

text: Gendered geographies of resistance, resilience and reworking in Aotearoa feminist geography scholarship Aotearoa New Zealand feminist geographies involve alliances of connected and vibrant researchers who pay close attention to the politics of knowledge production, power, intersectionality and decolonisation. Safe spaces to speak and write together have been nurtured over time ‘down under’ due to a collective politics of care and mentoring. This special issue demonstrates the strength of collective thinking on resistance, resilience and reworking contemporary geographical practice in Aotearoa. The four empirically based and theoretically informed articles develop new thinking about resistance to colonialism, patriarchy, racism, metricisation and oppression. These critical articles contribute to feminist geographical knowledges both locally and globally.

year: 2022-11-22

title: Me ko Māui: Harnessing the sun to provide better outcomes for marae and communities

authors: Greensill, Waikauri

abstract: Marae are the cultural centres of Māori communities, providing a space for important gatherings both joyful and sad. With the advent of solar energy capture technologies and rising electricity bills, many marae are becoming interested in whether a solar powered system will be beneficial for them. However, marae have unique electricity demand profiles, distinct from commonly modelled building types such as residential or commercial buildings. It is thus difficult to estimate an appropriate solar and battery system size based on annual or even monthly electricity usage data, which may be the only data readily available, requiring more in-depth analysis at a highly site-specific level to find an answer. This thesis aims to increase understanding around how solar power could benefit marae, first by investigating the characteristic electricity demand profile of marae, then by observing how proposed system configurations meet the demand. The potential community benefits arising from such a system was also investigated. Using a year’s worth of half-hourly data from three marae, five characteristic day types were found in the analysis of the demand profile, namely a “Non-Event” profile that maintained a low baseload and accounted for 70% of the days in a year, a “1-Day Event” profile that lasted only a few hours, and for events spanning multiple days a “Start”, “Middle” and “End” day profile that varied greatly in demand magnitude. The demand profiles were then used to develop an annual demand profile for an average marae that was broadly representative of a wide range of marae. Different configurations of solar and battery powered systems were then applied to the annual demand and a technoeconomic analysis performed to determine whether a specific configuration met the needs of the average marae or not, which then produced a range of acceptable system sizes based on the needs specified. Not many solar and battery configurations resulted in positive economic returns for the marae alone, but widening the scope of the analysis to the surrounding community allows other interests such as local grid resilience to be considered, some of which may justify a marae’s decision to invest in a non-economic system to gain better community benefits. While investigating the use of peer-to-peer energy trading and community energy scenarios, sharing excess energy generated by a system with the wider community was also found to improve the economic outlook of solar for marae.

text: Me ko Māui: Harnessing the sun to provide better outcomes for marae and communities Marae are the cultural centres of Māori communities, providing a space for important gatherings both joyful and sad. With the advent of solar energy capture technologies and rising electricity bills, many marae are becoming interested in whether a solar powered system will be beneficial for them. However, marae have unique electricity demand profiles, distinct from commonly modelled building types such as residential or commercial buildings. It is thus difficult to estimate an appropriate solar and battery system size based on annual or even monthly electricity usage data, which may be the only data readily available, requiring more in-depth analysis at a highly site-specific level to find an answer. This thesis aims to increase understanding around how solar power could benefit marae, first by investigating the characteristic electricity demand profile of marae, then by observing how proposed system configurations meet the demand. The potential community benefits arising from such a system was also investigated. Using a year’s worth of half-hourly data from three marae, five characteristic day types were found in the analysis of the demand profile, namely a “Non-Event” profile that maintained a low baseload and accounted for 70% of the days in a year, a “1-Day Event” profile that lasted only a few hours, and for events spanning multiple days a “Start”, “Middle” and “End” day profile that varied greatly in demand magnitude. The demand profiles were then used to develop an annual demand profile for an average marae that was broadly representative of a wide range of marae. Different configurations of solar and battery powered systems were then applied to the annual demand and a technoeconomic analysis performed to determine whether a specific configuration met the needs of the average marae or not, which then produced a range of acceptable system sizes based on the needs specified. Not many solar and battery configurations resulted in positive economic returns for the marae alone, but widening the scope of the analysis to the surrounding community allows other interests such as local grid resilience to be considered, some of which may justify a marae’s decision to invest in a non-economic system to gain better community benefits. While investigating the use of peer-to-peer energy trading and community energy scenarios, sharing excess energy generated by a system with the wider community was also found to improve the economic outlook of solar for marae.

year: 2024

title: An external heat pulse method for measurement of sap flow through fruit pedicels, leaf petioles and other small-diameter stems

authors: Clearwater, Michael J.

subjects: Actinidia chinensis

abstract: The external heat ratio method is described for measurement of low rates of sap flow in both directions through stems and other plant organs, including fruit pedicels, with diameters up to 5 mm and flows less than 2 g h⁻¹. Calibration was empirical, with heat pulse velocity (vh) compared to gravimetric measurements of sap flow. In the four stem types tested (Actinidia sp. fruit pedicels, Schefflera arboricola petioles, Pittosporum crassifolium stems and Fagus sylvatica stems), vh was linearly correlated with sap velocity (vs) up to a vs of approximately 0.007 cm s⁻¹, equivalent to a flow of 1.8 g h⁻¹ through a 3-mm-diameter stem. Minimum detectable vs was approximately 0.0001 cm s⁻¹, equivalent to 0.025 g h⁻¹ through a 3-mm-diameter stem. Sensitivity increased with bark removal. Girdling had no effect on short-term measurements of in vivo sap flow, suggesting that phloem flows were too low to be separated from xylem flows. Fluctuating ambient temperatures increased variability in outdoor sap flow measurements. However, a consistent diurnal time-course of fruit pedicel sap flow was obtained, with flows towards 75-day-old kiwifruit lagging behind evaporative demand and peaking at 0.3 g h⁻¹ in the late afternoon.

text: An external heat pulse method for measurement of sap flow through fruit pedicels, leaf petioles and other small-diameter stems The external heat ratio method is described for measurement of low rates of sap flow in both directions through stems and other plant organs, including fruit pedicels, with diameters up to 5 mm and flows less than 2 g h⁻¹. Calibration was empirical, with heat pulse velocity (vh) compared to gravimetric measurements of sap flow. In the four stem types tested (Actinidia sp. fruit pedicels, Schefflera arboricola petioles, Pittosporum crassifolium stems and Fagus sylvatica stems), vh was linearly correlated with sap velocity (vs) up to a vs of approximately 0.007 cm s⁻¹, equivalent to a flow of 1.8 g h⁻¹ through a 3-mm-diameter stem. Minimum detectable vs was approximately 0.0001 cm s⁻¹, equivalent to 0.025 g h⁻¹ through a 3-mm-diameter stem. Sensitivity increased with bark removal. Girdling had no effect on short-term measurements of in vivo sap flow, suggesting that phloem flows were too low to be separated from xylem flows. Fluctuating ambient temperatures increased variability in outdoor sap flow measurements. However, a consistent diurnal time-course of fruit pedicel sap flow was obtained, with flows towards 75-day-old kiwifruit lagging behind evaporative demand and peaking at 0.3 g h⁻¹ in the late afternoon.

year: 2009