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: Nitrogen fixation and bulk organic removal in a bleached krall pulp and paper mill treatment system

authors: Frost, Nicola M.

subjects: New Zealand Pulp & Paper industry

abstract: A study was undertaken to assess some effects of nitrogen fixation and bulk organic substrate removal in a New Zealand bleached kraft pulp and paper mill wastewater treatment system. A novel wastewater biological treatment system based on nitrogen fixation has been identified as having significant potential for application in full scale treatment of pulp and paper and other nitrogen deficient wastewaters. This study contributes information about the significance and role of nitrogen fixing bacteria in such a system and will benefit development and optimisation of a wastewater treatment system based on nitrogen fixation. 
The specific aims of the study were i) to identify the bulk organic substrates present in the mill's treatment system, ii) to study some effects of changing the wastewater composition on the processes occurring in a nitrogen fixing biological treatment system and iii) to obtain and characterise some of the nitrogen fixing microorganisms present in this system. 
Methanol, acetic acid and glucose accounted for approximately 43% of the soluble chemical oxygen demand entering the treatment system. The remaining 57% was unidentified in this study. Acetic acid was the first identified substrate removed from the treatment system, implicating this compound as the preferred substrate under these conditions. 
A laboratory continuous culture experiment demonstrated that increases in acetate and methanol concentrations in the wastewater did not affect specific substrate removal and nitrogen fixation rates in the system but may have changed the microbial population. Low biomass nitrogen results were obtained in this experiment and attributed to microbial intracellular storage of poly-β-hydroxybutyrate. 
Isolates were obtained from the mill's treatment system which were able to fix nitrogen under microaerophilic conditions. Four selected isolates were able to utilise methanol, acetic acid and glucose under nitrogen fixing conditions. All of these isolates removed acetic acid from a mixed carbon substrate medium before methanol and glucose, consistent with individual substrate removal found in the Tasman treatment system.

text: Nitrogen fixation and bulk organic removal in a bleached krall pulp and paper mill treatment system A study was undertaken to assess some effects of nitrogen fixation and bulk organic substrate removal in a New Zealand bleached kraft pulp and paper mill wastewater treatment system. A novel wastewater biological treatment system based on nitrogen fixation has been identified as having significant potential for application in full scale treatment of pulp and paper and other nitrogen deficient wastewaters. This study contributes information about the significance and role of nitrogen fixing bacteria in such a system and will benefit development and optimisation of a wastewater treatment system based on nitrogen fixation. 
The specific aims of the study were i) to identify the bulk organic substrates present in the mill's treatment system, ii) to study some effects of changing the wastewater composition on the processes occurring in a nitrogen fixing biological treatment system and iii) to obtain and characterise some of the nitrogen fixing microorganisms present in this system. 
Methanol, acetic acid and glucose accounted for approximately 43% of the soluble chemical oxygen demand entering the treatment system. The remaining 57% was unidentified in this study. Acetic acid was the first identified substrate removed from the treatment system, implicating this compound as the preferred substrate under these conditions. 
A laboratory continuous culture experiment demonstrated that increases in acetate and methanol concentrations in the wastewater did not affect specific substrate removal and nitrogen fixation rates in the system but may have changed the microbial population. Low biomass nitrogen results were obtained in this experiment and attributed to microbial intracellular storage of poly-β-hydroxybutyrate. 
Isolates were obtained from the mill's treatment system which were able to fix nitrogen under microaerophilic conditions. Four selected isolates were able to utilise methanol, acetic acid and glucose under nitrogen fixing conditions. All of these isolates removed acetic acid from a mixed carbon substrate medium before methanol and glucose, consistent with individual substrate removal found in the Tasman treatment system.

year: 1998

title: ‘Let’s Get Wild’: Sensuous Geographies of Kāwhia Kai and Hokitika Wildfoods Festivals in Aōtearoa New Zealand

authors: Modlik, Melanie

subjects: Food Festivals

abstract: Food Festivals allow communities to celebrate local food and drink. This original thesis examines the mutual relationship between food festival organisers, festival attendees and festival spaces. Two unique New Zealand regional food festivals – Kāwhia Kai on the West Coast of the North Island and Wildfoods Hokitika on the West Coast of the South Island - are critically examined. The research addresses three questions. First, how do these food festivals construct their locations and vice versa? Second, in what ways do food festivals contribute to place identity? And, third, how do food festival attendees sensually experience the festivals?
The concept of embodiment provides the overarching framework for this research. With academic interests in both tourism and geography, I weave understandings of culinary tourism, festivals, tourist embodied experiences, sensuality, visercality and abjection to address my research questions. I use this theoretical ‘toolbox’ alongside qualitative methodological approaches which enable research participants to express their embodied experiences and emotions. Ten semi-structured interviews were conducted with festival organisers and food stall holders. Participant ‘sensing’ was carried out in both Kāwhia and Hokitika. In thinking about the social, cultural and ‘felt’ aspects of food, I also use my own body as an instrument of research. Promotional texts were collected and all data analysed using critical discourse analysis.
The empirical material is divided into two themes. The first theme focuses on location and place identity. Concepts of ‘place attachment’ and ‘sense of belonging’ construct food festival regions. The formation of ‘new colonial’ and ‘new Māori’ traditions is another way in which these food festivals created unique place identities. The second theme highlights the embodied experiences and spaces of both food festivals. Bodily senses, place and spaces are created through visceral and abject reactions to food experiences.
Food festivals have the potential to enhance the economic, social and cultural wellbeing of regional communities. The success of food festivals, however, is dependent on multi-sensual embodied experiences.

text: ‘Let’s Get Wild’: Sensuous Geographies of Kāwhia Kai and Hokitika Wildfoods Festivals in Aōtearoa New Zealand Food Festivals allow communities to celebrate local food and drink. This original thesis examines the mutual relationship between food festival organisers, festival attendees and festival spaces. Two unique New Zealand regional food festivals – Kāwhia Kai on the West Coast of the North Island and Wildfoods Hokitika on the West Coast of the South Island - are critically examined. The research addresses three questions. First, how do these food festivals construct their locations and vice versa? Second, in what ways do food festivals contribute to place identity? And, third, how do food festival attendees sensually experience the festivals?
The concept of embodiment provides the overarching framework for this research. With academic interests in both tourism and geography, I weave understandings of culinary tourism, festivals, tourist embodied experiences, sensuality, visercality and abjection to address my research questions. I use this theoretical ‘toolbox’ alongside qualitative methodological approaches which enable research participants to express their embodied experiences and emotions. Ten semi-structured interviews were conducted with festival organisers and food stall holders. Participant ‘sensing’ was carried out in both Kāwhia and Hokitika. In thinking about the social, cultural and ‘felt’ aspects of food, I also use my own body as an instrument of research. Promotional texts were collected and all data analysed using critical discourse analysis.
The empirical material is divided into two themes. The first theme focuses on location and place identity. Concepts of ‘place attachment’ and ‘sense of belonging’ construct food festival regions. The formation of ‘new colonial’ and ‘new Māori’ traditions is another way in which these food festivals created unique place identities. The second theme highlights the embodied experiences and spaces of both food festivals. Bodily senses, place and spaces are created through visceral and abject reactions to food experiences.
Food festivals have the potential to enhance the economic, social and cultural wellbeing of regional communities. The success of food festivals, however, is dependent on multi-sensual embodied experiences.

year: 2015