title: Pared-down landscapes in Antarctica

authors: Cotton, C.A.

abstract: The frigid-arid climate that now prevails in ice-free parts of Victoria Land, Antarctica, inhibits glacial erosion. If certain landscapes, more or less remote from the great troughs of outlet glaciers, have been glaciated in the past, as seems very probable, landforms that resulted from glaciation have been replaced by surfaces of different origin.
A widespread landscape glaciation was probably contemporaneous with the excavation of large cirques which still survive in mountain summit areas.
Replacement of glaciated landforms by others, in a general paring down of the land surface to forms of moderate relief, seems to have resulted from the process of gravity removal of debris from precipitous rock outcrops that were retreating because of disintegration by salt weathering and were eventually eliminated, in most cases, so that the landscape became a mosaic of smooth denudation slopes inclined at 33° to 350.
In the Darwin Mountains ice-free area (80ºS) an advanced stage of such denudation with respect to a base level some 400 m above the present level of surrounding glaciers has produced some pyramidal landforms. Just above the present ice level, however, narrow Richter denudation slopes that border weathering rock faces are at only a juvenile stage of development. Thus the ice level appears to have stood alternately at about its present position and 400 m higher in Pleistocene interglacials and glacial ages respectively. The higher ice levels must have been due to extensions of the ice sheet seaward caused by groundings of the shelf ice during low glacio-eustatic stands of sea level

text: Pared-down landscapes in Antarctica The frigid-arid climate that now prevails in ice-free parts of Victoria Land, Antarctica, inhibits glacial erosion. If certain landscapes, more or less remote from the great troughs of outlet glaciers, have been glaciated in the past, as seems very probable, landforms that resulted from glaciation have been replaced by surfaces of different origin.
A widespread landscape glaciation was probably contemporaneous with the excavation of large cirques which still survive in mountain summit areas.
Replacement of glaciated landforms by others, in a general paring down of the land surface to forms of moderate relief, seems to have resulted from the process of gravity removal of debris from precipitous rock outcrops that were retreating because of disintegration by salt weathering and were eventually eliminated, in most cases, so that the landscape became a mosaic of smooth denudation slopes inclined at 33° to 350.
In the Darwin Mountains ice-free area (80ºS) an advanced stage of such denudation with respect to a base level some 400 m above the present level of surrounding glaciers has produced some pyramidal landforms. Just above the present ice level, however, narrow Richter denudation slopes that border weathering rock faces are at only a juvenile stage of development. Thus the ice level appears to have stood alternately at about its present position and 400 m higher in Pleistocene interglacials and glacial ages respectively. The higher ice levels must have been due to extensions of the ice sheet seaward caused by groundings of the shelf ice during low glacio-eustatic stands of sea level

year: 1971

title: Isotopic fractionation in a large herbivorous insect, the Auckland tree weta

authors: Wehi, Priscilla M.

subjects: discrimination factor

abstract: Determining diet and trophic position of species with stable isotopes requires appropriate trophic enrichment estimates between an animal and its potential foods. These estimates are particularly important for cryptic foragers where there is little comparative dietary information. Nonetheless, many trophic enrichment estimates are based on related taxa, without confirmation of accuracy using laboratory trials. We used stable isotope analysis to investigate diet and to resolve trophic relationships in a large endemic insect, the Auckland tree weta (Hemideina thoracica White). Comparisons of isotopes in plant foods fed to captive wetas with isotope ratios in their frass provided variable results, so frass isotope values had limited usefulness as a proxy indicator of trophic level. Isotopic values varied between different tissues, with trophic depletion of 15N highest in body fat and testes. Tissue fractionation was consistent in captive and wild caught wetas, and isotopic values were not significantly different between the two groups, suggesting that this weta species is primarily herbivorous. Whole-body values in captive wetas demonstrated trophic depletion (Δδ) for δ¹⁵N of about–0.77‰ and trophic enrichment of 4.28‰ for δ¹³C. These values differ from commonly estimated trophic enrichments for both insects and herbivores and indicate the importance of laboratory trials to determine trophic enrichment. Isotopic values for femur muscles from a number of local wild weta populations did not vary consistently with body weight or size, suggesting that juveniles eat the same foods as adults. Considerable variation among individuals within and between populations suggest that isotopic values are strongly influenced by food availability and individual foraging traits.

text: Isotopic fractionation in a large herbivorous insect, the Auckland tree weta Determining diet and trophic position of species with stable isotopes requires appropriate trophic enrichment estimates between an animal and its potential foods. These estimates are particularly important for cryptic foragers where there is little comparative dietary information. Nonetheless, many trophic enrichment estimates are based on related taxa, without confirmation of accuracy using laboratory trials. We used stable isotope analysis to investigate diet and to resolve trophic relationships in a large endemic insect, the Auckland tree weta (Hemideina thoracica White). Comparisons of isotopes in plant foods fed to captive wetas with isotope ratios in their frass provided variable results, so frass isotope values had limited usefulness as a proxy indicator of trophic level. Isotopic values varied between different tissues, with trophic depletion of 15N highest in body fat and testes. Tissue fractionation was consistent in captive and wild caught wetas, and isotopic values were not significantly different between the two groups, suggesting that this weta species is primarily herbivorous. Whole-body values in captive wetas demonstrated trophic depletion (Δδ) for δ¹⁵N of about–0.77‰ and trophic enrichment of 4.28‰ for δ¹³C. These values differ from commonly estimated trophic enrichments for both insects and herbivores and indicate the importance of laboratory trials to determine trophic enrichment. Isotopic values for femur muscles from a number of local wild weta populations did not vary consistently with body weight or size, suggesting that juveniles eat the same foods as adults. Considerable variation among individuals within and between populations suggest that isotopic values are strongly influenced by food availability and individual foraging traits.

year: 2010

title: Cultural justice, ethics and teaching

authors: Nairn, Ray

subjects: Maori

abstract: Te Tiriti o Waitangi provides both a basis for cultural justice in this society and an explication of the term; each of the articles identifying a significant aspect of cultural justice. First, there is the guarantee to the Maori signatories that the Crown would protect their independence - tino rangatiratanga, (also read as authority, autonomy or self-determination) [Article II]. In Article III Maori are promised that they will also have the “Rights and Privileges of British subjects”. Finally, in Article I, Maori cede to the Crown the right to govern, to make laws to protect all peoples from the evil consequences of lawlessness. The 1835 Declaration of Independence located legislative authority in the Wakaminenga (the gathered rangatira meeting in Congress); and in 1840, in the context of the Crown promises, Maori authorised the Crown to exercise that authority. For Maori Te Tiriti specifies cultural justice for interactions between Maori and settlers in the new society. Maori are guaranteed the right to self-determination (and the economic and social resources to make that practical) in their relations with New Zealand society. They are also entitled to the same opportunities as other citizens. The latter rights, embodied in local legislation and international covenants to which we are signatory, are not alternatives to the prior right of Maori people to their (cultural) autonomy. The exercise of legislative and organisational authority must be exercised in a manner consistent with the promises which clearly requires consultation and negotiation with Maori.

text: Cultural justice, ethics and teaching Te Tiriti o Waitangi provides both a basis for cultural justice in this society and an explication of the term; each of the articles identifying a significant aspect of cultural justice. First, there is the guarantee to the Maori signatories that the Crown would protect their independence - tino rangatiratanga, (also read as authority, autonomy or self-determination) [Article II]. In Article III Maori are promised that they will also have the “Rights and Privileges of British subjects”. Finally, in Article I, Maori cede to the Crown the right to govern, to make laws to protect all peoples from the evil consequences of lawlessness. The 1835 Declaration of Independence located legislative authority in the Wakaminenga (the gathered rangatira meeting in Congress); and in 1840, in the context of the Crown promises, Maori authorised the Crown to exercise that authority. For Maori Te Tiriti specifies cultural justice for interactions between Maori and settlers in the new society. Maori are guaranteed the right to self-determination (and the economic and social resources to make that practical) in their relations with New Zealand society. They are also entitled to the same opportunities as other citizens. The latter rights, embodied in local legislation and international covenants to which we are signatory, are not alternatives to the prior right of Maori people to their (cultural) autonomy. The exercise of legislative and organisational authority must be exercised in a manner consistent with the promises which clearly requires consultation and negotiation with Maori.

year: 1993