title: Impacts of conversion from forestry to pasture on soil physical properties of Vitrands (Pumice Soils) in the Central North Island, New Zealand

authors: Paripovic, Djuro

subjects: Pumice Soil

abstract: Abstract At least 30 000 hectares of land has been converted from plantation forest to pasture in the central North Island of New Zealand between 2000 and 2010. When forests are cleared for pasture the soil may undergo changes in soil structure affecting physical properties. The overall objective of this study was to investigate changes in soil physical properties in Pumice Soils following land use change from forest to pasture. Two study areas were identified; one near Tokoroa (Maxwell Farms), and one near Taupo (Wairakei Estate). At each study area a series of sites including: plantation pine forest, pasture converted from pine forest 2,3,4 and 5 years ago, and long term (>50 years) dairy, and sheep and beef pasture, were identified, all on Taupo Pumice Soil. Field and laboratory methods included measurement of; penetration resistance, degree of packing, soil dry bulk density, soil hydrophobicity, unsaturated and saturated hydraulic conductivity, soil moisture retention, aggregate stability, particle size distribution, and soil pH. There was increased soil compaction in the A horizon on recently converted sites compared to pine forest sites as evidenced by higher soil dry bulk density, increased penetration resistance, and degree of packing. At the Tokoroa study area the pine forest soil A horizon had a significantly lower dry bulk density ( mean 0.58 g/cm3) ( P < 0.05 ) than any of the pasture sites (mean 0.65 - 0.72 g/cm3). At the Taupo study area only long term dairy (mean 0.78 g/cm3) and the youngest pasture site (3 years since conversion from pine forest) (mean 0.74 g/cm3) had higher (P < 0.05) bulk density than the plantation pine forest soil. At the Tokoroa study area, the penetration resistance and degree of packing in the A horizon of the pine forest site was lower ( P< 0.01 ) than any other site. The degree of packing and penetration resistance at the Taupo study area in the A horizon of the pine forest site was lower ( P< 0.05 ) compared to 3 years old conversion and long term dairy pasture but was not significantly different from pastures converted 4 and 5 years ago. The water repellency of recently converted pastures was higher (P < 0.05) than pine forest at both study areas. Two of the three long-term pasture sites investigated had very low water repellency. The long term pasture sites had markedly higher total available water holding capacity than either the recently converted pastures or the pine forest sites. The pine forest soil water content at 10 kPa (field capacity) and 100 kPa (readily available water) was generally lower than pasture sites. At the Tokoroa study area there was no significant difference in unsaturated hydraulic conductivity between the pine forest soil and any other site. At Taupo the pine forest soil unsaturated hydraulic conductivity was higher (P < 0.05) than the most recent conversion site (3 years old) but not significantly different from other sites. At the Taupo study area none of the land uses had significantly different saturated infiltration rate compared to the pine forest. At the Tokoroa study area the pine forest saturated hydraulic conductivity was higher (P < 0.05) than the 5 years old conversion or the long term sheep and beef farm. The A horizon, at both study areas, was observed to be deepest under long term dairy farm followed by forest and shallowest on sites recently converted from pine plantation. There was no clear pattern of changes in soil colour, pedality or boundary distinctiveness and shape, between different sites. Aggregate stability of the Ap horizon was noticeably lower in recently converted pastures than in the pine forest or long term pasture sites. Soil pH values were generally in 4.5 to 5.9 ranges across all land uses in all horizons. The exception was the most recent conversions to pasture (2 and 3 years ago converted) at the Tokoroa study area which exceeded pH 6, presumably due to high rates (3.5 T/ha) of lime application during the conversion process.

text: Impacts of conversion from forestry to pasture on soil physical properties of Vitrands (Pumice Soils) in the Central North Island, New Zealand Abstract At least 30 000 hectares of land has been converted from plantation forest to pasture in the central North Island of New Zealand between 2000 and 2010. When forests are cleared for pasture the soil may undergo changes in soil structure affecting physical properties. The overall objective of this study was to investigate changes in soil physical properties in Pumice Soils following land use change from forest to pasture. Two study areas were identified; one near Tokoroa (Maxwell Farms), and one near Taupo (Wairakei Estate). At each study area a series of sites including: plantation pine forest, pasture converted from pine forest 2,3,4 and 5 years ago, and long term (>50 years) dairy, and sheep and beef pasture, were identified, all on Taupo Pumice Soil. Field and laboratory methods included measurement of; penetration resistance, degree of packing, soil dry bulk density, soil hydrophobicity, unsaturated and saturated hydraulic conductivity, soil moisture retention, aggregate stability, particle size distribution, and soil pH. There was increased soil compaction in the A horizon on recently converted sites compared to pine forest sites as evidenced by higher soil dry bulk density, increased penetration resistance, and degree of packing. At the Tokoroa study area the pine forest soil A horizon had a significantly lower dry bulk density ( mean 0.58 g/cm3) ( P < 0.05 ) than any of the pasture sites (mean 0.65 - 0.72 g/cm3). At the Taupo study area only long term dairy (mean 0.78 g/cm3) and the youngest pasture site (3 years since conversion from pine forest) (mean 0.74 g/cm3) had higher (P < 0.05) bulk density than the plantation pine forest soil. At the Tokoroa study area, the penetration resistance and degree of packing in the A horizon of the pine forest site was lower ( P< 0.01 ) than any other site. The degree of packing and penetration resistance at the Taupo study area in the A horizon of the pine forest site was lower ( P< 0.05 ) compared to 3 years old conversion and long term dairy pasture but was not significantly different from pastures converted 4 and 5 years ago. The water repellency of recently converted pastures was higher (P < 0.05) than pine forest at both study areas. Two of the three long-term pasture sites investigated had very low water repellency. The long term pasture sites had markedly higher total available water holding capacity than either the recently converted pastures or the pine forest sites. The pine forest soil water content at 10 kPa (field capacity) and 100 kPa (readily available water) was generally lower than pasture sites. At the Tokoroa study area there was no significant difference in unsaturated hydraulic conductivity between the pine forest soil and any other site. At Taupo the pine forest soil unsaturated hydraulic conductivity was higher (P < 0.05) than the most recent conversion site (3 years old) but not significantly different from other sites. At the Taupo study area none of the land uses had significantly different saturated infiltration rate compared to the pine forest. At the Tokoroa study area the pine forest saturated hydraulic conductivity was higher (P < 0.05) than the 5 years old conversion or the long term sheep and beef farm. The A horizon, at both study areas, was observed to be deepest under long term dairy farm followed by forest and shallowest on sites recently converted from pine plantation. There was no clear pattern of changes in soil colour, pedality or boundary distinctiveness and shape, between different sites. Aggregate stability of the Ap horizon was noticeably lower in recently converted pastures than in the pine forest or long term pasture sites. Soil pH values were generally in 4.5 to 5.9 ranges across all land uses in all horizons. The exception was the most recent conversions to pasture (2 and 3 years ago converted) at the Tokoroa study area which exceeded pH 6, presumably due to high rates (3.5 T/ha) of lime application during the conversion process.

year: 2011

title: Destratification – fact sheet

authors: Tempero, Grant Wayne

abstract: During summer, the surface waters of lakes warm and become less dense than the colder bottom waters. This process is known as stratification and prevents surface and bottom water mixing. Stratification can occur intermittently in shallower lakes or for up to 9 months in deeper lakes (Figure 1). Under natural conditions stratification normally breaks down during the winter months when surface temperatures equilibrate with the bottom of the lake.

text: Destratification – fact sheet During summer, the surface waters of lakes warm and become less dense than the colder bottom waters. This process is known as stratification and prevents surface and bottom water mixing. Stratification can occur intermittently in shallower lakes or for up to 9 months in deeper lakes (Figure 1). Under natural conditions stratification normally breaks down during the winter months when surface temperatures equilibrate with the bottom of the lake.

year: 2015

title: Formulaic Discourse Patterning in Mōteatea

authors: Roa, Te Raukura o Te Rangimarie

subjects: mōteatea

abstract: Oral formulaic composition, which involves the use of communally owned formulae of various kinds, is a common feature of verbal arts produced in many different languages. It is particularly associated with pre-literate cultures and tends to be gradually replaced by more individualistic verbal art forms when societies become literate. There are very few publications in which the analysis of mōteatea (Māori laments) is linked explicitly to oral formulaic theory. Nevertheless, there is, I believe, sufficient evidence in published sources to indicate that traditional mōteatea (defined here as mōteatea that are not fundamentally influenced by European cultural beliefs and practices) exhibit evidence of regularly recurring, conventional themes (such as death, separation, loss and travel) and motifs (such as the setting sun, the presence of rain or mist and sleeplessness).  There is, however, considerably less evidence that traditional mōteatea make extensive use of verbal formulae, that is, of the same or very similar groups of words derived from a common store of poetic resources. Although there are references in the literature to the conventionalized use of language in mōteatea, and although it has been claimed that there are at least some commonly recurring verbal expressions, this is by no means evidence of reliance on a common stock of verbal formulae. Indeed, no attempt has hitherto been made to define precisely what might be meant by the term 'oral formula' in the context of compositions in te reo Māori, something that is clearly required in view, in particular, of the fact that the phrasal structure of the language means that certain groupings (e.g. i te X; ki te X) are very likely to occur in certain contexts irrespective of genre. Furthermore, in the literature on oral formulaic composition, oral formulae are generally linked to particular metrical conditions and there is, it is argued here, no convincing empirically-based evidence that mōteatea conform to any common metrical structure or structures (see Chapters 2 and 4).

In the context of a critical review of selected literature on oral formulaic theory (Chapter 2) and mōteatea (Chapter 3), this thesis sets out to test the hypothesis that traditional mōteatea were composed, in whole or in large part, from a common stock of oral formulae. The conclusion, based on analysis of a selection of mōteatea included in Ngā mōteatea, a collection initially established by Sir Apirana Ngata, is that this hypothesis must be rejected (Chapter 4). However, a model derived from a review of selected literature on discourse structure (Chapter 5) was also applied to the analysis of a sample of these mōteatea (Chapter 6). On the basis of this analysis, it is concluded that they exhibit one of two very similar discourse prototypes, each of which involves a particular combination of discourse elements. What distinguishes the two prototypes is the fact that only one of them is characterized by the inclusion of hortatory sections in which the poet urges one or more of the protagonists to undergo one or more steps or stages required to achieve a particular outcome, such as entry into the spirit world or vengeance for death and/ or humiliation.

text: Formulaic Discourse Patterning in Mōteatea Oral formulaic composition, which involves the use of communally owned formulae of various kinds, is a common feature of verbal arts produced in many different languages. It is particularly associated with pre-literate cultures and tends to be gradually replaced by more individualistic verbal art forms when societies become literate. There are very few publications in which the analysis of mōteatea (Māori laments) is linked explicitly to oral formulaic theory. Nevertheless, there is, I believe, sufficient evidence in published sources to indicate that traditional mōteatea (defined here as mōteatea that are not fundamentally influenced by European cultural beliefs and practices) exhibit evidence of regularly recurring, conventional themes (such as death, separation, loss and travel) and motifs (such as the setting sun, the presence of rain or mist and sleeplessness).  There is, however, considerably less evidence that traditional mōteatea make extensive use of verbal formulae, that is, of the same or very similar groups of words derived from a common store of poetic resources. Although there are references in the literature to the conventionalized use of language in mōteatea, and although it has been claimed that there are at least some commonly recurring verbal expressions, this is by no means evidence of reliance on a common stock of verbal formulae. Indeed, no attempt has hitherto been made to define precisely what might be meant by the term 'oral formula' in the context of compositions in te reo Māori, something that is clearly required in view, in particular, of the fact that the phrasal structure of the language means that certain groupings (e.g. i te X; ki te X) are very likely to occur in certain contexts irrespective of genre. Furthermore, in the literature on oral formulaic composition, oral formulae are generally linked to particular metrical conditions and there is, it is argued here, no convincing empirically-based evidence that mōteatea conform to any common metrical structure or structures (see Chapters 2 and 4).

In the context of a critical review of selected literature on oral formulaic theory (Chapter 2) and mōteatea (Chapter 3), this thesis sets out to test the hypothesis that traditional mōteatea were composed, in whole or in large part, from a common stock of oral formulae. The conclusion, based on analysis of a selection of mōteatea included in Ngā mōteatea, a collection initially established by Sir Apirana Ngata, is that this hypothesis must be rejected (Chapter 4). However, a model derived from a review of selected literature on discourse structure (Chapter 5) was also applied to the analysis of a sample of these mōteatea (Chapter 6). On the basis of this analysis, it is concluded that they exhibit one of two very similar discourse prototypes, each of which involves a particular combination of discourse elements. What distinguishes the two prototypes is the fact that only one of them is characterized by the inclusion of hortatory sections in which the poet urges one or more of the protagonists to undergo one or more steps or stages required to achieve a particular outcome, such as entry into the spirit world or vengeance for death and/ or humiliation.

year: 2008