title: Stromatolite records of environmental change in perennially ice-covered Lake Joyce, McMurdo Dry Valleys, Antarctica

authors: Mackey, T.J.

subjects: Science & Technology

abstract: Calcite-rich columnar stromatolites grew in perennially ice-covered Lake Joyce in the McMurdo Dry Valleys, Antarctica, during a period of environmental change associated with rising lake level. Stromatolite calcite contains carbon and oxygen isotope records of changes to microbial activity in response to variable light environments and water chemistry through time. The stromatolites grew synchronously with correlative calcite zones. The innermost (oldest) calcite zone has a wide range of δ¹³Ccalcite values consistent with variable photosynthetic effects on local DIC ¹³C/¹²C. Subsequent calcite zones preserve a progressive enrichment in δ¹³Ccalcite values of approximately + 2.6‰ through time, with δ¹³Ccalcite values becoming less variable. This enrichment likely records the removal of ¹²C by photosynthesis from the DIC reservoir over decades, with photosynthetic effects decreasing as light levels became lower and more consistent through time. Mean δ¹⁸Ocalcite values of the innermost calcified zone were at least 1‰ lower than those of the other calcified zones (t test p-level < 0.001). The significant difference in δ¹⁸Ocalcite values between the innermost and other calcified zones could be a product of mixing source waters with different isotopic values associated with the initiation of lake stratification associated with rising lake level. Overall, Lake Joyce stromatolites record significant lateral variability in relative photosynthetic rate and long-lived lake water stratification with microbial modification of the DIC pool. Such processes provide criteria for interpreting microbial activity within polar paleolake deposits and may shed light on variability in lake environments associated with changing climate in the McMurdo Dry Valleys.

text: Stromatolite records of environmental change in perennially ice-covered Lake Joyce, McMurdo Dry Valleys, Antarctica Calcite-rich columnar stromatolites grew in perennially ice-covered Lake Joyce in the McMurdo Dry Valleys, Antarctica, during a period of environmental change associated with rising lake level. Stromatolite calcite contains carbon and oxygen isotope records of changes to microbial activity in response to variable light environments and water chemistry through time. The stromatolites grew synchronously with correlative calcite zones. The innermost (oldest) calcite zone has a wide range of δ¹³Ccalcite values consistent with variable photosynthetic effects on local DIC ¹³C/¹²C. Subsequent calcite zones preserve a progressive enrichment in δ¹³Ccalcite values of approximately + 2.6‰ through time, with δ¹³Ccalcite values becoming less variable. This enrichment likely records the removal of ¹²C by photosynthesis from the DIC reservoir over decades, with photosynthetic effects decreasing as light levels became lower and more consistent through time. Mean δ¹⁸Ocalcite values of the innermost calcified zone were at least 1‰ lower than those of the other calcified zones (t test p-level < 0.001). The significant difference in δ¹⁸Ocalcite values between the innermost and other calcified zones could be a product of mixing source waters with different isotopic values associated with the initiation of lake stratification associated with rising lake level. Overall, Lake Joyce stromatolites record significant lateral variability in relative photosynthetic rate and long-lived lake water stratification with microbial modification of the DIC pool. Such processes provide criteria for interpreting microbial activity within polar paleolake deposits and may shed light on variability in lake environments associated with changing climate in the McMurdo Dry Valleys.

year: 2018

title: Components of regional population growth, 1986-2001

authors: Pool, Ian

subjects: population growth

abstract: The vitality of a region is frequently assessed by looking at its population growth pattern. This is seen as being linked to its economic and social vibrancy. To better understand the dynamics of this growth pattern it is necessary to decompose population growth into the contributions of natural increase (births less deaths) and migration (both domestic and international). This provides a demographic accounting of the factors of population change which we use to analyse the degree to which the levels and impacts of these factors differ between the Regional Council Areas of New Zealand. We find large variations between Regional Council Areas in overall population growth for the three quinquennia between 1986 and 2001. The Auckland region experienced the largest growth, coming both from high natural increase and international migration, while the “sunbelt” regions of Bay of Plenty, Nelson-Tasman and Marlborough had high growth, but driven by internal migration. In other regions, such as Gisborne, West Coast and Southland population growth declined.

text: Components of regional population growth, 1986-2001 The vitality of a region is frequently assessed by looking at its population growth pattern. This is seen as being linked to its economic and social vibrancy. To better understand the dynamics of this growth pattern it is necessary to decompose population growth into the contributions of natural increase (births less deaths) and migration (both domestic and international). This provides a demographic accounting of the factors of population change which we use to analyse the degree to which the levels and impacts of these factors differ between the Regional Council Areas of New Zealand. We find large variations between Regional Council Areas in overall population growth for the three quinquennia between 1986 and 2001. The Auckland region experienced the largest growth, coming both from high natural increase and international migration, while the “sunbelt” regions of Bay of Plenty, Nelson-Tasman and Marlborough had high growth, but driven by internal migration. In other regions, such as Gisborne, West Coast and Southland population growth declined.

year: 2004-05

title: Rangatahi of Ngāi Te Rangi Iwi: Cultural belonging and connectedness

authors: Benton, Chelsea

subjects: Māori

abstract: Rangatahi Māori (Māori youth) have one of the highest suicide rates in the OECD, they leave school earlier and with less qualifications, and suffer from higher rates of unemployment, hospitalisation and conduct and substance disorders and abuse than non-Māori. Sadly, many rangatahi move into adulthood only to experience poorer physical and mental health, shorter lifespans, and lower socioeconomic status compared to that of non-Māori. With these poor health outcomes for rangatahi Māori in mind this research explores the nature of Māori identities as a foundation for wellness, meaning, and flourishing. More importantly, this research takes into consideration the negative impacts of the colonisation of Māori and their cultural identity and the inter-generational effects of this long term systematic nature of disadvantage. I posit that cultural connectedness and belonging can foster healthy psychological and behavioural outcomes for rangatahi Māori. The mixed-method approach taken within this research sits within a Kaupapa Māori framework and draws upon accounts of 16 rangatahi Māori, aged between 10 and 14 years, who participated in a Ngāi Te Rangi Iwi based leadership development programme that reconnects rangatahi Māori with traditional customs and practices of their ancestors to enhance their health and wellbeing. Findings suggest that connectedness and belonging are manifest through practices such as Pēpeha, whakapapa, and Whakataukī/whakatauāki and rangatahi Māori draw on this cultural knowledge base and cultural practices to empower themselves, their whānau, hapū and Iwi. Rangatahi Māori in this sample also identified that whānau was most important in their lives followed by engagement in Māori culture. Findings highlight how Iwi organisations are stepping up to lead their people to a brighter future. For Māori, engaging with their Māoritanga and Te Ao Māori not only addresses the negative impacts of colonialism, but unlocks cultural potential, and an enhanced sense of self which serves to empower rangatahi Māori, their whānau, hapū and Iwi.

text: Rangatahi of Ngāi Te Rangi Iwi: Cultural belonging and connectedness Rangatahi Māori (Māori youth) have one of the highest suicide rates in the OECD, they leave school earlier and with less qualifications, and suffer from higher rates of unemployment, hospitalisation and conduct and substance disorders and abuse than non-Māori. Sadly, many rangatahi move into adulthood only to experience poorer physical and mental health, shorter lifespans, and lower socioeconomic status compared to that of non-Māori. With these poor health outcomes for rangatahi Māori in mind this research explores the nature of Māori identities as a foundation for wellness, meaning, and flourishing. More importantly, this research takes into consideration the negative impacts of the colonisation of Māori and their cultural identity and the inter-generational effects of this long term systematic nature of disadvantage. I posit that cultural connectedness and belonging can foster healthy psychological and behavioural outcomes for rangatahi Māori. The mixed-method approach taken within this research sits within a Kaupapa Māori framework and draws upon accounts of 16 rangatahi Māori, aged between 10 and 14 years, who participated in a Ngāi Te Rangi Iwi based leadership development programme that reconnects rangatahi Māori with traditional customs and practices of their ancestors to enhance their health and wellbeing. Findings suggest that connectedness and belonging are manifest through practices such as Pēpeha, whakapapa, and Whakataukī/whakatauāki and rangatahi Māori draw on this cultural knowledge base and cultural practices to empower themselves, their whānau, hapū and Iwi. Rangatahi Māori in this sample also identified that whānau was most important in their lives followed by engagement in Māori culture. Findings highlight how Iwi organisations are stepping up to lead their people to a brighter future. For Māori, engaging with their Māoritanga and Te Ao Māori not only addresses the negative impacts of colonialism, but unlocks cultural potential, and an enhanced sense of self which serves to empower rangatahi Māori, their whānau, hapū and Iwi.

year: 2019