title: Subsidence Rates of Drained Agricultural Peatlands in New Zealand and the Relationship with Time since Drainage

authors: Pronger, Jack.

abstract: The drainage and conversion of peatlands to productive agro-ecosystems leads to ongoing surface subsidence because of densification (shrinkage and consolidation) and oxidation of the peat substrate. Knowing the ra0te of this surface subsidence is important for future land-use planning, carbon accounting, and economic analysis of drainage and pumping costs. We measured subsidence rates over the past decade at 119 sites across three large, agriculturally managed peatlands in the Waikato region, New Zealand. The average contemporary (2000s–2012) subsidence rate for Waikato peatlands was 19 ± 2 mm yr−1 (± SE) and was significantly less (p = 0.01) than the historic rate of 26 ± 1 mm yr−1 between the 1920s and 2000s. A reduction in the rate of subsidence through time was attributed to the transition from rapid initial consolidation and shrinkage to slower, long-term, ongoing oxidation. These subsidence rates agree well with a literature synthesis of temperate zone subsidence rates reported for similar lengths of time since drainage. A strong nonlinear relationship was found between temperate zone subsidence rates and time since initial peatland drainage: Subsidence (mm yr−1) = 226 × (years since drained)−0.59 (R2 = 0.88). This relationship suggests that time since drainage exerts strong control over the rate of peatland subsidence and that ongoing peatland subsidence rates can be predicted to gradually decline with time in the absence of major land disturbance.

text: Subsidence Rates of Drained Agricultural Peatlands in New Zealand and the Relationship with Time since Drainage The drainage and conversion of peatlands to productive agro-ecosystems leads to ongoing surface subsidence because of densification (shrinkage and consolidation) and oxidation of the peat substrate. Knowing the ra0te of this surface subsidence is important for future land-use planning, carbon accounting, and economic analysis of drainage and pumping costs. We measured subsidence rates over the past decade at 119 sites across three large, agriculturally managed peatlands in the Waikato region, New Zealand. The average contemporary (2000s–2012) subsidence rate for Waikato peatlands was 19 ± 2 mm yr−1 (± SE) and was significantly less (p = 0.01) than the historic rate of 26 ± 1 mm yr−1 between the 1920s and 2000s. A reduction in the rate of subsidence through time was attributed to the transition from rapid initial consolidation and shrinkage to slower, long-term, ongoing oxidation. These subsidence rates agree well with a literature synthesis of temperate zone subsidence rates reported for similar lengths of time since drainage. A strong nonlinear relationship was found between temperate zone subsidence rates and time since initial peatland drainage: Subsidence (mm yr−1) = 226 × (years since drained)−0.59 (R2 = 0.88). This relationship suggests that time since drainage exerts strong control over the rate of peatland subsidence and that ongoing peatland subsidence rates can be predicted to gradually decline with time in the absence of major land disturbance.

year: 2014

title: The rise of the fake reference

authors: Gibbons, Stephanie

abstract: This presentation discusses the risk of fake reference.

text: The rise of the fake reference This presentation discusses the risk of fake reference.

year: 2020

title: Moko – A Research Project

authors: Te Awekotuku, Ngahuia

subjects: Maori

abstract: Moko colours the lives, and the skins, of all the people involved in the making of this book “Mau Moko”, which began as the Marsden project, “Ta Moko – Culture, Body Modification, and the Psychology of Identity”, 2001-2005. We proposed to study the origins, significance, technology and practice of Ta Moko from the pre-contact period to contemporary times, and to explore how this important art form has become a dynamic and positive assertion of being Maori in our changing world.

text: Moko – A Research Project Moko colours the lives, and the skins, of all the people involved in the making of this book “Mau Moko”, which began as the Marsden project, “Ta Moko – Culture, Body Modification, and the Psychology of Identity”, 2001-2005. We proposed to study the origins, significance, technology and practice of Ta Moko from the pre-contact period to contemporary times, and to explore how this important art form has become a dynamic and positive assertion of being Maori in our changing world.

year: 2008