title: Accuracy assessment of land surface temperature retrievals from Landsat 7 ETM + in the Dry Valleys of Antarctica using iButton temperature loggers and weather station data

authors: Brabyn, Lars

subjects: Landsat

abstract: The McMurdo Dry Valleys of Antarctica are the largest snow/ice-free regions on this vast continent, comprising 1 % of the land mass. Due to harsh environmental conditions, the valleys are bereft of any vegetation. Land surface temperature is a key determinate of microclimate and a driver for sensible and latent heat fluxes of the surface. The Dry Valleys have been the focus of ecological studies as they arguably provide the simplest trophic structure suitable for modelling. In this paper, we employ a validation method for land surface temperatures obtained from Landsat 7 ETM + imagery and compared with in situ land surface temperature data collected from four transects totalling 45 iButtons. A single meteorological station was used to obtain a better understanding of daily and seasonal cycles in land surface temperatures. Results show a good agreement between the iButton and the Landsat 7 ETM + product for clear sky cases. We conclude that Landsat 7 ETM + derived land surface temperatures can be used at broad spatial scales for ecological and meteorological research.

text: Accuracy assessment of land surface temperature retrievals from Landsat 7 ETM + in the Dry Valleys of Antarctica using iButton temperature loggers and weather station data The McMurdo Dry Valleys of Antarctica are the largest snow/ice-free regions on this vast continent, comprising 1 % of the land mass. Due to harsh environmental conditions, the valleys are bereft of any vegetation. Land surface temperature is a key determinate of microclimate and a driver for sensible and latent heat fluxes of the surface. The Dry Valleys have been the focus of ecological studies as they arguably provide the simplest trophic structure suitable for modelling. In this paper, we employ a validation method for land surface temperatures obtained from Landsat 7 ETM + imagery and compared with in situ land surface temperature data collected from four transects totalling 45 iButtons. A single meteorological station was used to obtain a better understanding of daily and seasonal cycles in land surface temperatures. Results show a good agreement between the iButton and the Landsat 7 ETM + product for clear sky cases. We conclude that Landsat 7 ETM + derived land surface temperatures can be used at broad spatial scales for ecological and meteorological research.

year: 2013

title: The potential for waterbirds to act as a vector for zooplankton dispersal in the North Island, New Zealand

authors: Jamieson, Kelly

subjects: Zooplankton

abstract: Zooplankton are essential components of freshwater ecosystems by controlling algal growth and sustaining higher trophic levels. Freshwater zooplankton are geographically isolated and are incapable of active dispersal to new freshwater sites. The dispersal of zooplankton can occur through natural dispersal vectors (e.g., wind, rain or waterfowl) or through human-mediated dispersal vectors (e.g., accidental or deliberate introductions). Dispersal of zooplankton is vital for maintaining gene flow between isolated sites and colonising new habitats. Zooplankton diapause eggs are well suited for dispersal as they are resistant to harsh conditions, e.g., digestion, drying and freezing. Diapause eggs increase the chance of survival in unfavourable conditions and are an important part of a zooplankton’s life cycle. This paper analyses New Zealand waterbirds’ dispersal of zooplankton internally (endozoochory) and externally (ectozoochory). 

This study quantified the dispersal of zooplankton internally (endozoochory) using the faecal droppings collected from waterbirds at two New Zealand Lakes. Faecal droppings were collected from Mallard Ducks, Canadian Geese, Greylag Geese, Black Swans and Australian Coots from Lake Rotoroa and Lake Rotorua. A total of 50 eggs were found in the faecal droppings of waterbirds, with a mean number of 0.75 eggs found per dropping. These results indicate that waterbirds are consuming zooplankton eggs. However, no significant difference was observed in the propagule count among waterbird species. Therefore it was unlikely that the waterbird species impacted the abundance or viability of diapause eggs. 

The sediment experiment showed zooplankton are inhabiting the shores of Lake Rotorua and Lake Rotoroa, where waterbirds are likely to come in contact with diapause located within the sediment. In Lake Rotorua, diapausing eggs from six species of rotifers, cladocerans, copepods and ostracods hatched from the littoral sediments. Strikingly, no hatching was observed in the littoral sediments from Lake Rotoroa. These results suggest that diapausing eggs are readily available to be picked up by waterbirds for external dispersal (ectozoochory). This study quantified the potential for zooplankton to be dispersed by waterbirds internally (endozoochory) and externally (ectozoochory). Results suggest that waterbird dispersal of zooplankton is occurring, but the numbers being transported are low. Although, the transport of a few individuals may be enough to achieve gene flow. Waterbirds are not be the primary vector for the dispersal of zooplankton. Human-mediated contributions e.g., shipping-related activities (ballast tanks), may play a more significant role than waterbirds in the dispersal of zooplankton.

text: The potential for waterbirds to act as a vector for zooplankton dispersal in the North Island, New Zealand Zooplankton are essential components of freshwater ecosystems by controlling algal growth and sustaining higher trophic levels. Freshwater zooplankton are geographically isolated and are incapable of active dispersal to new freshwater sites. The dispersal of zooplankton can occur through natural dispersal vectors (e.g., wind, rain or waterfowl) or through human-mediated dispersal vectors (e.g., accidental or deliberate introductions). Dispersal of zooplankton is vital for maintaining gene flow between isolated sites and colonising new habitats. Zooplankton diapause eggs are well suited for dispersal as they are resistant to harsh conditions, e.g., digestion, drying and freezing. Diapause eggs increase the chance of survival in unfavourable conditions and are an important part of a zooplankton’s life cycle. This paper analyses New Zealand waterbirds’ dispersal of zooplankton internally (endozoochory) and externally (ectozoochory). 

This study quantified the dispersal of zooplankton internally (endozoochory) using the faecal droppings collected from waterbirds at two New Zealand Lakes. Faecal droppings were collected from Mallard Ducks, Canadian Geese, Greylag Geese, Black Swans and Australian Coots from Lake Rotoroa and Lake Rotorua. A total of 50 eggs were found in the faecal droppings of waterbirds, with a mean number of 0.75 eggs found per dropping. These results indicate that waterbirds are consuming zooplankton eggs. However, no significant difference was observed in the propagule count among waterbird species. Therefore it was unlikely that the waterbird species impacted the abundance or viability of diapause eggs. 

The sediment experiment showed zooplankton are inhabiting the shores of Lake Rotorua and Lake Rotoroa, where waterbirds are likely to come in contact with diapause located within the sediment. In Lake Rotorua, diapausing eggs from six species of rotifers, cladocerans, copepods and ostracods hatched from the littoral sediments. Strikingly, no hatching was observed in the littoral sediments from Lake Rotoroa. These results suggest that diapausing eggs are readily available to be picked up by waterbirds for external dispersal (ectozoochory). This study quantified the potential for zooplankton to be dispersed by waterbirds internally (endozoochory) and externally (ectozoochory). Results suggest that waterbird dispersal of zooplankton is occurring, but the numbers being transported are low. Although, the transport of a few individuals may be enough to achieve gene flow. Waterbirds are not be the primary vector for the dispersal of zooplankton. Human-mediated contributions e.g., shipping-related activities (ballast tanks), may play a more significant role than waterbirds in the dispersal of zooplankton.

year: 2022

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