title: Unravelling upbuilding pedogenesis in tephra and loess sequences in New Zealand using tephrochronology

authors: Lowe, David J.

subjects: soil-sediment

abstract: The genesis of soils developed in either tephra or loess on stable sites differs markedly from that of soils developed on rock because classical topdown processes operate in conjuction with geological processes whereby material is added to the land surface so that the soils form by upbuilding pedogenesis.
Understanding the genesis of such soils (typically Andisols and Alfisols, respectively) often requires a stratigraphic approach combined with an appreciation of buried soil horizons and polygenesis. In New Zealand, calendrically-dated tephras provide an advantage for assessing rates of upbuilding through chronostratigraphy. Many Andisol profiles form by upbuilding pedogenesis as younger tephra materials are deposited on top of older ones. The resultant profile character reflects interplay between the rate at which tephras are added to the land surface and topdown processes that produce andic materials and horizons. In loess terrains, upbuilding pedogenesis since c. 25,000 years ago is associated with maximum rates of loess accumulation c. 3 10 mm per century, sufficiently slow for soil-forming processes to continue to operate as the land surface gradually rises. Thus, Alfisol subsoil features are only weakly developed and Bw or B(x) horizons typically are formed. In contrast, topdown pedogenesis is associated with minimal or zero loess accumulation, the land surface elevation remains essentially constant, and subsoil features become more strongly developed and Bg, Bt, or Bx horizons typically are formed.

text: Unravelling upbuilding pedogenesis in tephra and loess sequences in New Zealand using tephrochronology The genesis of soils developed in either tephra or loess on stable sites differs markedly from that of soils developed on rock because classical topdown processes operate in conjuction with geological processes whereby material is added to the land surface so that the soils form by upbuilding pedogenesis.
Understanding the genesis of such soils (typically Andisols and Alfisols, respectively) often requires a stratigraphic approach combined with an appreciation of buried soil horizons and polygenesis. In New Zealand, calendrically-dated tephras provide an advantage for assessing rates of upbuilding through chronostratigraphy. Many Andisol profiles form by upbuilding pedogenesis as younger tephra materials are deposited on top of older ones. The resultant profile character reflects interplay between the rate at which tephras are added to the land surface and topdown processes that produce andic materials and horizons. In loess terrains, upbuilding pedogenesis since c. 25,000 years ago is associated with maximum rates of loess accumulation c. 3 10 mm per century, sufficiently slow for soil-forming processes to continue to operate as the land surface gradually rises. Thus, Alfisol subsoil features are only weakly developed and Bw or B(x) horizons typically are formed. In contrast, topdown pedogenesis is associated with minimal or zero loess accumulation, the land surface elevation remains essentially constant, and subsoil features become more strongly developed and Bg, Bt, or Bx horizons typically are formed.

year: 2010

title: Ecology of the invertebrate predatory fauna across Centre Bank, Tauranga Harbour

authors: Putt, Fiona Gloria

subjects: Centre Bank

abstract: The distribution, abundance, population size structure and behaviour of three common invertebrate predators were studied on Centre Bank, the flood-tidal delta of Tauranga Harbour. The study assessed the role of the predators in controlling the distribution and abundance of bivalve shellfish and provided information concerning the biology of Centre Bank for Port of Tauranga Ltd.
Two broad-scale surveys were conducted to describe the broad-scale spatial patterns of Patiriella regularis, Coscinasterias calamaria and Cominella adspersa. Results found P. regularis was the numerically dominant species across Centre Bank and it maintained a widespread distribution over the sampling period. C. calamaria was of low abundance and typically exhibited a patchy distribution. C. adspersa was also found to be of low abundance and similarly distributed as C. calamaria. Size structures of all 3 species comprised mostly adults in both surveys.
Temporal monitoring at finer scales was undertaken, two-monthly, to describe small-scale spatial patterns. P. regularis was found at similar densities to that of the large-scale surveys and it was the most prevalent species across the grid; C. calamaria was present at higher abundances within a small patch of the grid and appeared stable over time. C. adspersa was initially absent from the grid, but became more abundant and widespead over the 9 month sampling period.
Investigations included monitoring the natural movement behaviour of C. adspersa in relation to tidal currents and the body condition. Results showed the directions moved and distances displaced by C. adspersa may be influenced by the rate and direction of current movement and therefore potentially influencing the dispersal ability of C. adspersa, in relation to available prey. An experiment to determine the body condition of C. adspersa in the field suggested that food deprivation may be less detrimental than first realised, or that C. adspersa is able to feed on a greater variety of food types than known of.
Little evidence was found that indicated predation was an important mechanism controlling bivalve populations across Centre Bank. However, predators may be potentially important as scavengers of decaying or dead organisms. Their predatory activities may also provide shell substrate for macroalgae, and this, in combination with dense aggregations of C. calamaria, appeared to provide habitat for small fishes.

text: Ecology of the invertebrate predatory fauna across Centre Bank, Tauranga Harbour The distribution, abundance, population size structure and behaviour of three common invertebrate predators were studied on Centre Bank, the flood-tidal delta of Tauranga Harbour. The study assessed the role of the predators in controlling the distribution and abundance of bivalve shellfish and provided information concerning the biology of Centre Bank for Port of Tauranga Ltd.
Two broad-scale surveys were conducted to describe the broad-scale spatial patterns of Patiriella regularis, Coscinasterias calamaria and Cominella adspersa. Results found P. regularis was the numerically dominant species across Centre Bank and it maintained a widespread distribution over the sampling period. C. calamaria was of low abundance and typically exhibited a patchy distribution. C. adspersa was also found to be of low abundance and similarly distributed as C. calamaria. Size structures of all 3 species comprised mostly adults in both surveys.
Temporal monitoring at finer scales was undertaken, two-monthly, to describe small-scale spatial patterns. P. regularis was found at similar densities to that of the large-scale surveys and it was the most prevalent species across the grid; C. calamaria was present at higher abundances within a small patch of the grid and appeared stable over time. C. adspersa was initially absent from the grid, but became more abundant and widespead over the 9 month sampling period.
Investigations included monitoring the natural movement behaviour of C. adspersa in relation to tidal currents and the body condition. Results showed the directions moved and distances displaced by C. adspersa may be influenced by the rate and direction of current movement and therefore potentially influencing the dispersal ability of C. adspersa, in relation to available prey. An experiment to determine the body condition of C. adspersa in the field suggested that food deprivation may be less detrimental than first realised, or that C. adspersa is able to feed on a greater variety of food types than known of.
Little evidence was found that indicated predation was an important mechanism controlling bivalve populations across Centre Bank. However, predators may be potentially important as scavengers of decaying or dead organisms. Their predatory activities may also provide shell substrate for macroalgae, and this, in combination with dense aggregations of C. calamaria, appeared to provide habitat for small fishes.

year: 1996

title: Proposing an indigenous power of veto in Aotearoa New Zealand

authors: Te Aho, Linda

abstract: Tom Fookes was an architect of New Zealand's Resource Management Act passed in 1991 (RMA). When interviewed about his life's work, Tom responded that he had sought to create a 'fair, integrated consideration of the decisions and policy to do with the social, economic and environmental conditions of our people'. I am told that he worked hard to provide a fair opportunity for all people to have a voice in decisions that affect them and places they care about. Processes were included in the RMA to allow this to occur, with particular provisions for a distinctive Maori voice. Because of these provisions, and the Act's lodestar of sustainable resource management, the RMA was promoted as one of the 'world's finest national environmental policies'.

text: Proposing an indigenous power of veto in Aotearoa New Zealand Tom Fookes was an architect of New Zealand's Resource Management Act passed in 1991 (RMA). When interviewed about his life's work, Tom responded that he had sought to create a 'fair, integrated consideration of the decisions and policy to do with the social, economic and environmental conditions of our people'. I am told that he worked hard to provide a fair opportunity for all people to have a voice in decisions that affect them and places they care about. Processes were included in the RMA to allow this to occur, with particular provisions for a distinctive Maori voice. Because of these provisions, and the Act's lodestar of sustainable resource management, the RMA was promoted as one of the 'world's finest national environmental policies'.

year: 2015