title: Rapid carbon accumulation in a peatland following Late Holocene tephra deposition, New Zealand

authors: Ratcliffe, Joshua Lee

abstract: Contemporary measurements of carbon (C) accumulation rates in peatlands around the world often show the C sink to be stronger on average than at times in the past. Alteration of global nutrient cycles could be contributing to elevated carbon accumulation in the present day. Here we examine the effect of volcanic inputs of nutrients on peatland C accumulation in Moanatuatua Bog, New Zealand, by examining a high-resolution Late Holocene C accumulation record during which powerful volcanic eruptions occurred, depositing two visible rhyolitic tephra layers (Taupo, 232 ± 10 CE; Kaharoa, 1314 ± 12 CE). Carbon accumulation rates since c. 50 CE, well before any human presence, increased from a background rate of 23 g C m−2 yr−1 up to 110 g C m−2 yr−1 following the deposition of the Taupo Tephra, and 84 g C m−2 yr−1 following the deposition of the Kaharoa Tephra. Smaller but nevertheless marked increases in C accumulation additionally occurred in association with the deposition of three andesitic-dacitic cryptotephras (each ≤ ∼1 mm thick) of the Tufa Trig Formation between the Taupo and Kaharoa events. These five periods of elevated C uptake, especially those associated with the relatively thick Taupo and Kaharoa tephras, were accompanied by shifts in nutrient stoichiometry, indicating that there was greater availability of phosphorus (P) relative to nitrogen (N) and C during the period of high C uptake. Such P was almost certainly derived from volcanic sources, with P being present in the volcanic glass at Moanatuatua, and many of the eruptions described being associated with the local deposition of the P rich mineral apatite. We found peatland C accumulation to be tightly coupled to N and P accumulation, suggesting nutrient inputs exert a strong control on rates of peat accumulation. Nutrient stoichiometry indicated a strong ability to recover P within the ecosystem, with C:P ratios being higher than most other peatlands in the literature. We conclude that nutrient inputs, deriving from volcanic eruptions, have been very important for C accumulation rates in the past. Therefore, the elevated nutrient inputs occurring in the present day could offer a more plausible explanation, as opposed to a climatic component, for observed high contemporary C accumulation in New Zealand peatlands.

text: Rapid carbon accumulation in a peatland following Late Holocene tephra deposition, New Zealand Contemporary measurements of carbon (C) accumulation rates in peatlands around the world often show the C sink to be stronger on average than at times in the past. Alteration of global nutrient cycles could be contributing to elevated carbon accumulation in the present day. Here we examine the effect of volcanic inputs of nutrients on peatland C accumulation in Moanatuatua Bog, New Zealand, by examining a high-resolution Late Holocene C accumulation record during which powerful volcanic eruptions occurred, depositing two visible rhyolitic tephra layers (Taupo, 232 ± 10 CE; Kaharoa, 1314 ± 12 CE). Carbon accumulation rates since c. 50 CE, well before any human presence, increased from a background rate of 23 g C m−2 yr−1 up to 110 g C m−2 yr−1 following the deposition of the Taupo Tephra, and 84 g C m−2 yr−1 following the deposition of the Kaharoa Tephra. Smaller but nevertheless marked increases in C accumulation additionally occurred in association with the deposition of three andesitic-dacitic cryptotephras (each ≤ ∼1 mm thick) of the Tufa Trig Formation between the Taupo and Kaharoa events. These five periods of elevated C uptake, especially those associated with the relatively thick Taupo and Kaharoa tephras, were accompanied by shifts in nutrient stoichiometry, indicating that there was greater availability of phosphorus (P) relative to nitrogen (N) and C during the period of high C uptake. Such P was almost certainly derived from volcanic sources, with P being present in the volcanic glass at Moanatuatua, and many of the eruptions described being associated with the local deposition of the P rich mineral apatite. We found peatland C accumulation to be tightly coupled to N and P accumulation, suggesting nutrient inputs exert a strong control on rates of peat accumulation. Nutrient stoichiometry indicated a strong ability to recover P within the ecosystem, with C:P ratios being higher than most other peatlands in the literature. We conclude that nutrient inputs, deriving from volcanic eruptions, have been very important for C accumulation rates in the past. Therefore, the elevated nutrient inputs occurring in the present day could offer a more plausible explanation, as opposed to a climatic component, for observed high contemporary C accumulation in New Zealand peatlands.

year: 2020

title: Considering pedagogical content knowledge in the context of research on teaching: An example from technology.

authors: Jones, Alister

subjects: teaching

abstract: When thinking about teaching, the pedagogical content knowledge of teachers cannot be ignored. We argue that pedagogical content knowledge is a major determiner of teaching practice and is central to teachers' curriculum decision-making at the classroom level. This paper takes a sociocultural perspective on the importance of developing teachers' pedagogical content knowledge. From our classroom-based research in technology education and the past research on pedagogical content knowledge we propose a model of pedagogical content knowledge with seven characteristics that we believe are important for effective teaching.

text: Considering pedagogical content knowledge in the context of research on teaching: An example from technology. When thinking about teaching, the pedagogical content knowledge of teachers cannot be ignored. We argue that pedagogical content knowledge is a major determiner of teaching practice and is central to teachers' curriculum decision-making at the classroom level. This paper takes a sociocultural perspective on the importance of developing teachers' pedagogical content knowledge. From our classroom-based research in technology education and the past research on pedagogical content knowledge we propose a model of pedagogical content knowledge with seven characteristics that we believe are important for effective teaching.

year: 2003

title: Restoring Indigneous Law and Justice Traditions

authors: Cook, Michelle Lynn

subjects: Indigenous peoples

abstract: Restoring indigenous people's law and their ability to practice their justice traditions is a fundamental aspect of non-discrimination, decolonization, self-governance, self-determination, and social justice. The critical application and interpretation of indigenous people's law has revolutionary potentiality to transform, confront, and heal multiple forms of oppression such as environmental destruction, patriarchy, and the prison/criminal justice system. The sovereign jurisgenerative (law making) power of indigenous peoples is a site of profound hope for the revitalization of indigenous law and justice traditions restores legal principles and values of sacredness, harmony, balance, and interconnectivity within human relationships and with the natural world. Revitalizing indigenous law is a way to re-construct the self and society while also finding and re-connecting to new/old ways of being human. This thesis focuses on both Navajo and Māori practices and visions of law and justice; the challenges and, successes they have faced and the hopes they have of living by their law. Indigenous peoples, their ways of being, their wisdom, laws, and philosophies, must be respected, protected, and preserved not only because they contribute to humanity's richness and cultural diversity but also because they are living examples of  a more just, dignified, and ecologically sustainable society, which can serve all humanity.

text: Restoring Indigneous Law and Justice Traditions Restoring indigenous people's law and their ability to practice their justice traditions is a fundamental aspect of non-discrimination, decolonization, self-governance, self-determination, and social justice. The critical application and interpretation of indigenous people's law has revolutionary potentiality to transform, confront, and heal multiple forms of oppression such as environmental destruction, patriarchy, and the prison/criminal justice system. The sovereign jurisgenerative (law making) power of indigenous peoples is a site of profound hope for the revitalization of indigenous law and justice traditions restores legal principles and values of sacredness, harmony, balance, and interconnectivity within human relationships and with the natural world. Revitalizing indigenous law is a way to re-construct the self and society while also finding and re-connecting to new/old ways of being human. This thesis focuses on both Navajo and Māori practices and visions of law and justice; the challenges and, successes they have faced and the hopes they have of living by their law. Indigenous peoples, their ways of being, their wisdom, laws, and philosophies, must be respected, protected, and preserved not only because they contribute to humanity's richness and cultural diversity but also because they are living examples of  a more just, dignified, and ecologically sustainable society, which can serve all humanity.

year: 2010