Changing fluxes of sediments and salts as recorded in lower River Murray wetlands, Australia
- Gell, Peter, Fluin, Jennie, Tibby, John, Haynes, Deborah, Khanum, Syeda, Walsh, Brendan, Hancock, Gary, Harrison, Jennifer, Zawadzki, Atun, Little, Fiona
- Authors: Gell, Peter , Fluin, Jennie , Tibby, John , Haynes, Deborah , Khanum, Syeda , Walsh, Brendan , Hancock, Gary , Harrison, Jennifer , Zawadzki, Atun , Little, Fiona
- Date: 2006
- Type: Conference proceedings
- Full Text:
- Description: The River Murray basin, Australia's largest, has been significantly impacted by changed flow regimes and increased fluxes of salts and sediments since settlement in the 1840s. The river's flood plain hosts an array of cut-off meanders, levee lakes and basin depression lakes that archive historical changes. Pre-European sedimentation rates are typically approx. 0.1-1 mm year-1, while those in the period after European arrival are typically 10 to 30 fold greater. This increased sedimentation corresponds to a shift in wetland trophic state from submerged macrophytes in clear waters to phytoplankton-dominated, turbid systems. There is evidence for a decline in sedimentation in some natural wetlands after river regulation from the 1920s, but with the maintenance of the phytoplankton state. Fossil diatom assemblages reveal that, while some wetlands had saline episodes before settlement, others became saline after, and as early as the 1880s. The oxidation of sulphurous salts deposited after regulation has induced hyperacidity in a number of wetlands in recent years. While these wetlands are rightly perceived as being heavily impacted, other, once open water systems, that have infilled and now support rich macrophyte beds, are used as interpretive sites. The rate of filling, however, suggests that the lifespan of these wetlands is short. The rate of wetland loss through such increased infilling is unlikely to be matched by future scouring as regulation has eliminated middle order floods from the lower catchment.
- Authors: Gell, Peter , Fluin, Jennie , Tibby, John , Haynes, Deborah , Khanum, Syeda , Walsh, Brendan , Hancock, Gary , Harrison, Jennifer , Zawadzki, Atun , Little, Fiona
- Date: 2006
- Type: Conference proceedings
- Full Text:
- Description: The River Murray basin, Australia's largest, has been significantly impacted by changed flow regimes and increased fluxes of salts and sediments since settlement in the 1840s. The river's flood plain hosts an array of cut-off meanders, levee lakes and basin depression lakes that archive historical changes. Pre-European sedimentation rates are typically approx. 0.1-1 mm year-1, while those in the period after European arrival are typically 10 to 30 fold greater. This increased sedimentation corresponds to a shift in wetland trophic state from submerged macrophytes in clear waters to phytoplankton-dominated, turbid systems. There is evidence for a decline in sedimentation in some natural wetlands after river regulation from the 1920s, but with the maintenance of the phytoplankton state. Fossil diatom assemblages reveal that, while some wetlands had saline episodes before settlement, others became saline after, and as early as the 1880s. The oxidation of sulphurous salts deposited after regulation has induced hyperacidity in a number of wetlands in recent years. While these wetlands are rightly perceived as being heavily impacted, other, once open water systems, that have infilled and now support rich macrophyte beds, are used as interpretive sites. The rate of filling, however, suggests that the lifespan of these wetlands is short. The rate of wetland loss through such increased infilling is unlikely to be matched by future scouring as regulation has eliminated middle order floods from the lower catchment.
Palaeoenvironmental change in tropical Australasia over the last 30,000 years - a synthesis by the OZ-INTIMATE group
- Reeves, Jessica, Bostock, Helen, Ayliffe, Linda, Barrows, Timothy, De Deckker, Patrick, Devriendt, Laurent, Dunbar, Gavin, Drysdale, Russell, Fitzsimmons, Kathryn, Gagan, Michael, Griffiths, Michael, Haberle, Simon, Jansen, John, Krause, Claire, Lewis, Stephen, McGregor, Helen, Mooney, Scott, Moss, Patrick, Nanson, Gerald, Purcell, Anthony, van der Kaars, Sander
- Authors: Reeves, Jessica , Bostock, Helen , Ayliffe, Linda , Barrows, Timothy , De Deckker, Patrick , Devriendt, Laurent , Dunbar, Gavin , Drysdale, Russell , Fitzsimmons, Kathryn , Gagan, Michael , Griffiths, Michael , Haberle, Simon , Jansen, John , Krause, Claire , Lewis, Stephen , McGregor, Helen , Mooney, Scott , Moss, Patrick , Nanson, Gerald , Purcell, Anthony , van der Kaars, Sander
- Date: 2013
- Type: Text , Journal article
- Relation: Quaternary Science Reviews Vol. 74, no. (2013), p. 97-114
- Full Text:
- Reviewed:
- Description: The tropics are the major source of heat and moisture for the Australasian region. Determining the tropics' response over time to changes in climate forcing mechanisms, such as summer insolation, and the effects of relative sea level on exposed continental shelves during the Last Glacial period, is an ongoing process of re-evaluation. We present a synthesis of climate proxy data from tropical Australasia spanning the last 30,000 years that incorporates deep sea core, coral, speleothem, pollen, charcoal and terrestrial sedimentary records.Today, seasonal variability is governed largely by the annual migration of the inter-tropical convergence zone (ITCZ), influencing this region most strongly during the austral summer. However, the position of the ITCZ has varied through time. Towards the end of Marine Isotope Stage (MIS) 3, conditions were far wetter throughout the region, becoming drier first in the south. Universally cooler land and sea-surface temperature (SST) were characteristic of the Last Glacial Maximum, with drier conditions than previously, although episodic wet periods are noted in the fluvial records of northern Australia. The deglacial period saw warming first in the Coral Sea and then the Indonesian seas, with a pause in this trend around the time of the Antarctic Cold Reversal (c. 14.5ka), coincident with the flooding of the Sunda Shelf. Wetter conditions occurred first in Indonesia around 17ka and northern Australia after 14ka. The early Holocene saw a peak in marine SST to the northwest and northeast of Australia. Modern vegetation was first established on Indonesia, then progressively south and eastward to NE Australia. Flores and the Atherton Tablelands show a dry period around 11.6ka, steadily becoming wetter through the early Holocene. The mid-late Holocene was punctuated by millennial-scale variability, associated with the El Niño-Southern Oscillation; this is evident in the marine, coral, speleothem and pollen records of the region. © 2012.
- Description: 4 Earth Sciences
- Description: 21 History And Archaelogy
- Description: 2003011213
- Authors: Reeves, Jessica , Bostock, Helen , Ayliffe, Linda , Barrows, Timothy , De Deckker, Patrick , Devriendt, Laurent , Dunbar, Gavin , Drysdale, Russell , Fitzsimmons, Kathryn , Gagan, Michael , Griffiths, Michael , Haberle, Simon , Jansen, John , Krause, Claire , Lewis, Stephen , McGregor, Helen , Mooney, Scott , Moss, Patrick , Nanson, Gerald , Purcell, Anthony , van der Kaars, Sander
- Date: 2013
- Type: Text , Journal article
- Relation: Quaternary Science Reviews Vol. 74, no. (2013), p. 97-114
- Full Text:
- Reviewed:
- Description: The tropics are the major source of heat and moisture for the Australasian region. Determining the tropics' response over time to changes in climate forcing mechanisms, such as summer insolation, and the effects of relative sea level on exposed continental shelves during the Last Glacial period, is an ongoing process of re-evaluation. We present a synthesis of climate proxy data from tropical Australasia spanning the last 30,000 years that incorporates deep sea core, coral, speleothem, pollen, charcoal and terrestrial sedimentary records.Today, seasonal variability is governed largely by the annual migration of the inter-tropical convergence zone (ITCZ), influencing this region most strongly during the austral summer. However, the position of the ITCZ has varied through time. Towards the end of Marine Isotope Stage (MIS) 3, conditions were far wetter throughout the region, becoming drier first in the south. Universally cooler land and sea-surface temperature (SST) were characteristic of the Last Glacial Maximum, with drier conditions than previously, although episodic wet periods are noted in the fluvial records of northern Australia. The deglacial period saw warming first in the Coral Sea and then the Indonesian seas, with a pause in this trend around the time of the Antarctic Cold Reversal (c. 14.5ka), coincident with the flooding of the Sunda Shelf. Wetter conditions occurred first in Indonesia around 17ka and northern Australia after 14ka. The early Holocene saw a peak in marine SST to the northwest and northeast of Australia. Modern vegetation was first established on Indonesia, then progressively south and eastward to NE Australia. Flores and the Atherton Tablelands show a dry period around 11.6ka, steadily becoming wetter through the early Holocene. The mid-late Holocene was punctuated by millennial-scale variability, associated with the El Niño-Southern Oscillation; this is evident in the marine, coral, speleothem and pollen records of the region. © 2012.
- Description: 4 Earth Sciences
- Description: 21 History And Archaelogy
- Description: 2003011213
Having enough cultural food? A qualitative exploration of the experiences of migrants in a regional area of Australia
- Yeoh, Joanne, Lê, Quynh, Terry, Daniel, McManamey, Rosa
- Authors: Yeoh, Joanne , Lê, Quynh , Terry, Daniel , McManamey, Rosa
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of Food Research Vol. 4, no. 2 (2014), p. 16
- Full Text:
- Reviewed:
- Description: The notion of food security encompasses the ability of individuals, households and communities to acquire food that is healthy, sustainable, affordable, appropriate and accessible. Despite Australia’s current ability to produce more food than required for its population, there has been substantial evidence demonstrating that many Australians struggle to feed themselves, particularly those from a cultural and linguistically diverse (CALD) background. This qualitative phenomenological study investigated the experiences of food security among migrants in a regional area of Australia (Tasmania). 33 semi-structured interviews were conducted with Tasmanian migrants. The interviews were analysed thematically using Nvivo 10.0 and three main themes emerged: (1) migrant’s experiences of food security in Tasmania; (2) the factors that influence migrant food security in Tasmania; and (3) acculturation strategies. Participants were satisfied with their current food security in Tasmania but they still encountered some challenges in the availability, accessibility and affordability of healthy and cultural food. Factors that influenced their food security were educational background, the language barrier, socioeconomic status, geographical isolation, and their cultural background. Migrants managed to adapt to the new food culture by using different acculturation strategies. Migrants residing in Tasmania encounter a diverse number of challenges pertaining to food security and use different food security strategies while acculturating to the new environment. These findings may inform other migrant communities in Australia, relevant non-government organisations and government departments and suggest strategies to address food security challenges among migrants.
- Authors: Yeoh, Joanne , Lê, Quynh , Terry, Daniel , McManamey, Rosa
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of Food Research Vol. 4, no. 2 (2014), p. 16
- Full Text:
- Reviewed:
- Description: The notion of food security encompasses the ability of individuals, households and communities to acquire food that is healthy, sustainable, affordable, appropriate and accessible. Despite Australia’s current ability to produce more food than required for its population, there has been substantial evidence demonstrating that many Australians struggle to feed themselves, particularly those from a cultural and linguistically diverse (CALD) background. This qualitative phenomenological study investigated the experiences of food security among migrants in a regional area of Australia (Tasmania). 33 semi-structured interviews were conducted with Tasmanian migrants. The interviews were analysed thematically using Nvivo 10.0 and three main themes emerged: (1) migrant’s experiences of food security in Tasmania; (2) the factors that influence migrant food security in Tasmania; and (3) acculturation strategies. Participants were satisfied with their current food security in Tasmania but they still encountered some challenges in the availability, accessibility and affordability of healthy and cultural food. Factors that influenced their food security were educational background, the language barrier, socioeconomic status, geographical isolation, and their cultural background. Migrants managed to adapt to the new food culture by using different acculturation strategies. Migrants residing in Tasmania encounter a diverse number of challenges pertaining to food security and use different food security strategies while acculturating to the new environment. These findings may inform other migrant communities in Australia, relevant non-government organisations and government departments and suggest strategies to address food security challenges among migrants.
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