title: Comparison of earthworm and chemical assays of the bioavailability of aged 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, and heavy metals in orchard soils

authors: Gaw, Sally K.

subjects: Bioavailability

abstract: Orchard soils can contain elevated concentrations of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p′-DDE), 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (p,p′-DDT), and heavy metals as a result of historical agrichemical applications. The bioavailability of p,p′-DDE, p,p′-DDT, As, Cd, Cu, and Pb from five field-aged New Zealand orchards and three grazing soils was assessed by using a 28-d bioassay with Aporrectodea caliginosa and chemical assays. Significant relationships were found between total soil and earthworm tissue concentrations for p,p′-DDE (p < 0.001), p,p′-DDT (p < 0.001), Cu (p < 0.001), and Pb (p < 0.01). Two neutral salt solutions, 0.01 M CaCl2 and 1 M NH4NO3, were used as surrogate measures of the bioavailability of heavy metals. Copper was the only heavy metal for which significant correlations were found between neutral-salt-extractable and earthworm tissue concentrations (p < 0.001). Up to 28% of the aged DDT residues were released from the soils by Tenax over a 24-h extraction period. Significant relationships (p < 0.01) between the Tenax-extractable and earthworm tissue concentrations for p,p′-DDE and p,p′-DDT showed that Tenax provides a good surrogate measure of the bioavailability of these compounds to A. caliginosa. Surprisingly, there was a similarly significant relationship (p < 0.001) between the total soil and earthworm tissue concentrations for p,p′-DDE and p,p′-DDT, suggesting that total soil concentrations alone were sufficient to predict uptake by A. caliginosa. These results demonstrate that the aged agrichemical residues in orchard soils, and particularly p,p′-DDE and p,p′-DDT, remain highly bioavailable to A. caliginosa despite decades of weathering and continue to present an environmental risk

text: Comparison of earthworm and chemical assays of the bioavailability of aged 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, and heavy metals in orchard soils Orchard soils can contain elevated concentrations of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p′-DDE), 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (p,p′-DDT), and heavy metals as a result of historical agrichemical applications. The bioavailability of p,p′-DDE, p,p′-DDT, As, Cd, Cu, and Pb from five field-aged New Zealand orchards and three grazing soils was assessed by using a 28-d bioassay with Aporrectodea caliginosa and chemical assays. Significant relationships were found between total soil and earthworm tissue concentrations for p,p′-DDE (p < 0.001), p,p′-DDT (p < 0.001), Cu (p < 0.001), and Pb (p < 0.01). Two neutral salt solutions, 0.01 M CaCl2 and 1 M NH4NO3, were used as surrogate measures of the bioavailability of heavy metals. Copper was the only heavy metal for which significant correlations were found between neutral-salt-extractable and earthworm tissue concentrations (p < 0.001). Up to 28% of the aged DDT residues were released from the soils by Tenax over a 24-h extraction period. Significant relationships (p < 0.01) between the Tenax-extractable and earthworm tissue concentrations for p,p′-DDE and p,p′-DDT showed that Tenax provides a good surrogate measure of the bioavailability of these compounds to A. caliginosa. Surprisingly, there was a similarly significant relationship (p < 0.001) between the total soil and earthworm tissue concentrations for p,p′-DDE and p,p′-DDT, suggesting that total soil concentrations alone were sufficient to predict uptake by A. caliginosa. These results demonstrate that the aged agrichemical residues in orchard soils, and particularly p,p′-DDE and p,p′-DDT, remain highly bioavailable to A. caliginosa despite decades of weathering and continue to present an environmental risk

year: 2012

title: An exploratory model and economic evaluation of the use of bio-reengineered trees in plantation forestry

authors: Bohorova, Svetlana Ognianova

abstract: The research embodied in the thesis represents a broad conceptual framework regarding the recent developments in the science of biotechnology and their applications to the commercial goals of plantation forestry. The specific developments of tree biotechnology are outlined, with a particular interest in Eucalyptus grandis and its hybrids. A brief overview of the international regulatory schemes for protecting intellectual property rights, as well as for safeguarding the biosafety of commercial deployment of genetically engineered plants is developed in order to outline the advantages and disadvantages in investment decisions regarding plantation forestry of bio-reengineered eucalyptus trees. A more detailed examination of investment potential in this area is undertaken for New Zealand and Argentina, considering their favourable site-specific characteristics for maximizing the growth potential and the quality of eucalypts. To make the picture of investment in the production and growing of bio-reengineered trees even more focused, the goals of a company are matched to the engineered properties of the natural resource and their effects on the marginal changes of the overall chain of production in the forestry industry. 
Given the above broad framework of developments in tree biotechnology, an economic analysis is conducted in order to evaluate the gains associated with producing, growing and utilizing bio-reengineered trees for the production of specific wood products (e.g. mouldings). A detailed model is developed in which each stage of the production process (selection and re-engineering; plantation forest management; processing and reprocessing; market) is examined in its own merit, and stage-specific assumptions about input/output relationships, as well as cost-benefit factors are established. 
The qualitative assumptions made in the exploratory model are the base for conducting an economic evaluation of the gains associated with the use of bio-reengineered trees. It is found that the gains in net present value terms from growing the bio-reengineered trees in a shorter rotation length are significant. Such gains, however, are due to both the intertemporal changes involved in shortening the rotation period, as well as to changes of in the product worth due to the higher quality of the grown trees. Thus, an evaluation of the specific gains associated with quality change is also undertaken, where the contribution of each genetic trait of interest (herbicide resistance, insect resistance, lignin enhancement) to changes in the product worth is examined separately. A simple sensitivity analysis is developed to help examine the effects of each trait on the profitability of growing bio-reengineered trees. The internal rate of return of growing the 'superior' trees seems to be more sensitive to changes in the factors associated with lignin enhancement. This, however, is not a general rule and it is susceptible to alterations dependent on the magnitude of the cost factors associated with the other two traits. Given that the gains captured from growing -the bio-reengineered trees are attributed to both the technologist and the grower, royalty schemes are developed to suggest the alternative ways of distributing the gains from technological innovation. Finally, it is found that the gains from utilization of bio-reengineered trees are not only captured at harvest, but also a significant increase in the internal rate of return is associated with processing better and more uniform logs for specific high-quality wood products.

text: An exploratory model and economic evaluation of the use of bio-reengineered trees in plantation forestry The research embodied in the thesis represents a broad conceptual framework regarding the recent developments in the science of biotechnology and their applications to the commercial goals of plantation forestry. The specific developments of tree biotechnology are outlined, with a particular interest in Eucalyptus grandis and its hybrids. A brief overview of the international regulatory schemes for protecting intellectual property rights, as well as for safeguarding the biosafety of commercial deployment of genetically engineered plants is developed in order to outline the advantages and disadvantages in investment decisions regarding plantation forestry of bio-reengineered eucalyptus trees. A more detailed examination of investment potential in this area is undertaken for New Zealand and Argentina, considering their favourable site-specific characteristics for maximizing the growth potential and the quality of eucalypts. To make the picture of investment in the production and growing of bio-reengineered trees even more focused, the goals of a company are matched to the engineered properties of the natural resource and their effects on the marginal changes of the overall chain of production in the forestry industry. 
Given the above broad framework of developments in tree biotechnology, an economic analysis is conducted in order to evaluate the gains associated with producing, growing and utilizing bio-reengineered trees for the production of specific wood products (e.g. mouldings). A detailed model is developed in which each stage of the production process (selection and re-engineering; plantation forest management; processing and reprocessing; market) is examined in its own merit, and stage-specific assumptions about input/output relationships, as well as cost-benefit factors are established. 
The qualitative assumptions made in the exploratory model are the base for conducting an economic evaluation of the gains associated with the use of bio-reengineered trees. It is found that the gains in net present value terms from growing the bio-reengineered trees in a shorter rotation length are significant. Such gains, however, are due to both the intertemporal changes involved in shortening the rotation period, as well as to changes of in the product worth due to the higher quality of the grown trees. Thus, an evaluation of the specific gains associated with quality change is also undertaken, where the contribution of each genetic trait of interest (herbicide resistance, insect resistance, lignin enhancement) to changes in the product worth is examined separately. A simple sensitivity analysis is developed to help examine the effects of each trait on the profitability of growing bio-reengineered trees. The internal rate of return of growing the 'superior' trees seems to be more sensitive to changes in the factors associated with lignin enhancement. This, however, is not a general rule and it is susceptible to alterations dependent on the magnitude of the cost factors associated with the other two traits. Given that the gains captured from growing -the bio-reengineered trees are attributed to both the technologist and the grower, royalty schemes are developed to suggest the alternative ways of distributing the gains from technological innovation. Finally, it is found that the gains from utilization of bio-reengineered trees are not only captured at harvest, but also a significant increase in the internal rate of return is associated with processing better and more uniform logs for specific high-quality wood products.

year: 1997

title: Te mātauranga whakatere waka

authors: Tuaupiki, Jackie Whetumarama

abstract: Hei tēnei tuhinga e whai ake nei, ka tirohia te hangarau waka a ngā tūpuna o Te Moana nui a Kiwa i whakawhiti ai rātou ki ō rātou moutere tae atu ki te mātauranga whakatere waka me te arotahi o te titiro ki te whakatinanatanga o aua mātauranga. Ka tāmutu i konā, ka pūhia te titiro i runga i ngā huarere o Poronīhia e kite ai tātou i ngā āhuatanga o Tāwhirimātea i ōna moutere me ngā wero ki te whakatere waka i ērā huarere.

text: Te mātauranga whakatere waka Hei tēnei tuhinga e whai ake nei, ka tirohia te hangarau waka a ngā tūpuna o Te Moana nui a Kiwa i whakawhiti ai rātou ki ō rātou moutere tae atu ki te mātauranga whakatere waka me te arotahi o te titiro ki te whakatinanatanga o aua mātauranga. Ka tāmutu i konā, ka pūhia te titiro i runga i ngā huarere o Poronīhia e kite ai tātou i ngā āhuatanga o Tāwhirimātea i ōna moutere me ngā wero ki te whakatere waka i ērā huarere.

year: 2017