- Isaac, Bronwyn, Cooke, Raylene, Simmons, Dianne, Hogan, Fiona
- Authors: Isaac, Bronwyn , Cooke, Raylene , Simmons, Dianne , Hogan, Fiona
- Date: 2008
- Type: Text , Journal article
- Relation: Landscape and Urban Planning Vol. 84, no. (2008), p. 212-218
- Full Text: false
- Reviewed:
- Description: Urban expansion is a principal process threatening biodiversity globally. It is predicted that over half of the world's population will reside in urban centres by 2010. If we are to conserve biodiversity, a shift in perspective from traditional ecological studies based in natural environments, to studies based in less natural environments is paramount. To effectively conserve species which occur in urban environments, comprehensive analysis is necessary to determine the processes that are driving this urban usage. Geographical Information Systems (GIS) technology provides a valuable tool for efficient spatial analysis and predictive mapping of species distributions. This study used GIS to analyze current breeding sites for the powerful owl, a vulnerable top order predator in urban Melbourne, Australia. GIS analysis suggests that a number of ecological attributes were influencing powerful owl usage of urban environments. Using these ecological attributes, predictive mapping was undertaken, which identified a number of potential breeding sites for powerful owls within urbanized Melbourne. Urban environments are traditionally perceived as “the wastelands” of natural environments, however, this study demonstrates that they have the potential to support apex predators, an important finding for the management of rare and threatened species.
Urbanization affects the trophic structure of arboreal arthropod communities
- Christie, Fiona, Cassis, Gerasimos, Hochuli, Dieter
- Authors: Christie, Fiona , Cassis, Gerasimos , Hochuli, Dieter
- Date: 2010
- Type: Text , Journal article
- Relation: Urban Ecosystems Vol. 13, no. 2 (2010), p. 169-180
- Full Text: false
- Description: Urbanization is one of the most significant causes of habitat fragmentation on the planet, resulting in substantial losses of biodiversity and disruptions to ecological processes. We examined the effects of urbanization on the diversity and abundance of arboreal invertebrates in a dominant tree species (Angophora costata) in a highly urbanized landscape in Sydney, Australia, identifying the potential ecological consequences of shifts in diversity. We hypothesized that trophic structure would be influenced by landscape context with a greater richness and abundance of invertebrates in small remnants and edges. Canopy arthropods were sampled via beating from trees in 15 sites in three landscape contexts; five large patches of continuous vegetation, five edges of large patches and five small urban remnants. Trees in large patches supported fewer individuals compared to trees in small urban remnants and edge sites. The composition of assemblages and overall trophic structure also differed between edges and large patches, with a greater abundance of grazing insects in edges. No differences were detected between small urban remnants and edges, suggesting that observed differences might be attributed to an edge effect as opposed to an area effect per se. These changes in trophic structure, revealing a greater abundance of grazing herbivores and a reduced abundance of predators and parasitoids in edge sites, are consistent with work describing elevated levels of herbivory in edges of remnant vegetation. Future management of remnant urban vegetation and associated biodiversity requires not only an understanding of how trophic status influences the extent of responses by arboreal invertebrate communities, but also how these will affect ecosystem functioning. © 2009 Springer Science+Business Media, LLC.
- Description: 2003007386
- Wilson, Joab, Bekessy, Sarah, Parris, Kirsten, Gordon, Ascelin, Heard, Geoffrey, Wintle, Brendan
- Authors: Wilson, Joab , Bekessy, Sarah , Parris, Kirsten , Gordon, Ascelin , Heard, Geoffrey , Wintle, Brendan
- Date: 2012
- Type: Text , Journal article
- Relation: Austral Ecology Vol.38, no. 1 (2012), p.11-22
- Full Text: false
- Reviewed:
- Description: Climate change and urbanization are among the most serious threats to amphibians, although little is known about their combined effects. We used a predictive spatial habitat suitability model to explore the potential impacts of climate change and urban development on the spotted marsh frog (Limnodynastes tasmaniensis) on the urban-fringe of Melbourne, Australia. The CSIRO climate-change predictions for the region indicate likely temperature increases of 3°C, and annual rainfall reductions of around 200mm by the year 2070. Much of the study area overlaps a region that has been identified as one of the city's growth corridors. We used Bayesian logistic regression modelling to estimate current and future habitat suitability of pond sites in the Merri Creek catchment, exploring a range of best- to worst-case scenarios through the use of hydrological and urbanization models. Our predictions for 2070, even under a moderate climate-change scenario, suggest that the majority of ponds in the study area will be dry throughout much of the year. This has obvious implications for L.tasmaniensis, which is an aquatic breeding species. However, in the short term, urbanization is likely to have a more significant effect on the distribution of L.tasmaniensis in the Merri Creek catchment, particularly if development moves beyond the current urban growth boundary. The combined effects of climate change and urbanization could have a profound impact on the species, potentially causing it to disappear from within the study area. We provide recommendations for including such predictive models in urban planning and restoration activities to prepare for future conservation challenges. © 2012 The Authors. Journal compilation © 2012 Ecological Society of Australia.
When more is less : Urban remnants support high bird abundance but diversity varies
- Fitzsimons, James, Antos, Mark, Palmer, Grant
- Authors: Fitzsimons, James , Antos, Mark , Palmer, Grant
- Date: 2011
- Type: Text , Journal article
- Relation: Pacific Conservation Biology Vol. 17, no. 1 (2011), p. 97-109
- Full Text: false
- Reviewed:
- Description: Urban remnant vegetation, especially where it occurs in public parks, allows for relatively easy access for ongoing biodiversity monitoring. However, relatively little baseline information on bird species distribution and abundance across a range of identifiable urban remnants appears in the published literature. We surveyed the relative abundance and distribution of birds across urban and suburban remnant vegetation in Melbourne, Australia. One hundred and six species were recorded, of which 98 were indigenous. Red wattlebirds had the highest mean relative abundance with 2.94 birds/ha, followed by rainbow lorikeets (2.51), noisy miners (1.93), brown thornbills (1.75) and spotted doves (0.96). There was no obvious trend between overall relative abundance and the size of the remnant, in contrast to species richness which was positively correlated with remnant size. The data revealed that some species were either totally restricted to, or more abundant in, larger remnants and generally absent from smaller remnants. Some of the more common birds (crimson rosella, superb fairy-wren, spotted pardalote and black-faced cuckoo-shrike) recorded during this study were detected at similar densities to those found in comparable vegetation to the east of Melbourne within a largely forested landscape. Other species occurred at much lower densities (e.g., white-browed scrubwren, brown thornbill, eastern yellow robin and grey fantail) or had habitat requirements or ecological characteristics that could place them at risk of further decline or local extinction in the urban area. We identify a suite of bird species of potential conservation concern within Melbourne's urban landscape. The establishment of repeatable, fixed-point, and long-term monitoring sites will allow for repeat surveying over time and provide an early warning of population declines, or conversely an indication of population increase for other species.
Ecological processes associated with different animal taxa in urban environments
- Evans, Maldwyn, Barton, Philip, Westgate, Martin, Soga, Masashi, Fujita, Go, Miyashita, Tadashi
- Authors: Evans, Maldwyn , Barton, Philip , Westgate, Martin , Soga, Masashi , Fujita, Go , Miyashita, Tadashi
- Date: 2021
- Type: Text , Journal article
- Relation: Ecosphere Vol. 12, no. 8 (2021), p.
- Full Text:
- Reviewed:
- Description: Urbanization is increasing globally with wide-ranging consequences for biodiversity and the ecological processes it performs. Yet knowledge of the range of ecological processes supported by biodiversity in urban environments, and the different taxa that perform these processes is poorly understood. We used a text-analysis approach to identify the research trends and gaps in knowledge in the literature on ecological processes provided by animals in urban environments. We found a divide in urban ecological processes research that grouped studies into those with an explicit link to ecological processes and those that focused on biodiversity and made an implicit link to ecological processes. We also found that the dominant taxa in urban ecological processes research were insects, which has more than twice as many studies as birds or mammals, potentially due to their recognized and explicit link to key processes and services (e.g., pollination, pollution biomonitoring) and disservices (e.g., pests, disease transmission). We found a further split between terrestrial and aquatic studies, with urban aquatic studies also declining in relative prevalence over the last 20 yr. To consolidate and advance research on ecological processes in urban environments, we suggest it will be important to bridge the divide between studies on explicit services and others on more general biodiversity. This might be achieved by placing greater focus on the processes provided by non-insect taxa, and by integrating aquatic and terrestrial perspectives. © 2021 The Authors.
- Authors: Evans, Maldwyn , Barton, Philip , Westgate, Martin , Soga, Masashi , Fujita, Go , Miyashita, Tadashi
- Date: 2021
- Type: Text , Journal article
- Relation: Ecosphere Vol. 12, no. 8 (2021), p.
- Full Text:
- Reviewed:
- Description: Urbanization is increasing globally with wide-ranging consequences for biodiversity and the ecological processes it performs. Yet knowledge of the range of ecological processes supported by biodiversity in urban environments, and the different taxa that perform these processes is poorly understood. We used a text-analysis approach to identify the research trends and gaps in knowledge in the literature on ecological processes provided by animals in urban environments. We found a divide in urban ecological processes research that grouped studies into those with an explicit link to ecological processes and those that focused on biodiversity and made an implicit link to ecological processes. We also found that the dominant taxa in urban ecological processes research were insects, which has more than twice as many studies as birds or mammals, potentially due to their recognized and explicit link to key processes and services (e.g., pollination, pollution biomonitoring) and disservices (e.g., pests, disease transmission). We found a further split between terrestrial and aquatic studies, with urban aquatic studies also declining in relative prevalence over the last 20 yr. To consolidate and advance research on ecological processes in urban environments, we suggest it will be important to bridge the divide between studies on explicit services and others on more general biodiversity. This might be achieved by placing greater focus on the processes provided by non-insect taxa, and by integrating aquatic and terrestrial perspectives. © 2021 The Authors.
Losing stormwater: 60 years of urbanisation and reduced downstream flow
- Ebbs, David, Dahlhaus, Peter, Barton, Andrew, Kandra, Harpreet
- Authors: Ebbs, David , Dahlhaus, Peter , Barton, Andrew , Kandra, Harpreet
- Date: 2018
- Type: Text , Conference paper
- Relation: 10th International Conference on Water Sensitive Urban Design: Creating water sensitive communities (WSUD 2018 & Hydropolis 2018), 12-15 February 2018, Perth, Western Australia p. 142-151
- Full Text:
- Reviewed:
- Description: The potential for stormwater to supplement traditional water supplies from upstream catchments or groundwater is high, with claims that the quantity of additional runoff from impervious surfaces in a modern city in a temperate climate is greater than the total potable water demand. To ensure the success of Integrated Urban Water Management, it must consider the broad context of catchment management and the cumulative effect of all factors including river health. Ballarat, an inland city of approximately 100,000 people in south-eastern Australia, has many attributes necessary to potentially exploit stormwater. Given the doubling of population, tripling of residences and 90% increase in average residence size over the past 60 years, over which time flow data is available for the downstream waterway, it might be expected that the flow in the river downstream of the city within the catchment would reflect additional stormwater runoff. However, no increase in flow was detected between 1957 and 1996 while flow over the past 20 years has reduced by 60%. A water balance shows this decrease was not due to extractions as the stream has been a consistent net receiver of water from other catchments. Modelling data from the Australian Water Resources Assessment indicates that the reduction in streamflow is double what might be expected due to climatic variations. Between 1957 and 1996 there was no significant difference between modelled runoff and actual flow, however from 1997 onwards there is a significant divergence. While lower runoff may be expected during the period of drought, the rainfall-runoff relationship does not return to previous levels during latter years of rainfall. The effect is greater during higher flow months, which has significance when identifying potential additional water resources. Base flow has been reduced to the point where dry weather flow is reliant on waste water treatment plant and mine discharge. This study indicates that while impervious surfaces generate higher runoff which can cause environmental damage, making stormwater an attractive water source, consideration must be given to the impacts on the whole catchment when assessing alternative supply options.
- Authors: Ebbs, David , Dahlhaus, Peter , Barton, Andrew , Kandra, Harpreet
- Date: 2018
- Type: Text , Conference paper
- Relation: 10th International Conference on Water Sensitive Urban Design: Creating water sensitive communities (WSUD 2018 & Hydropolis 2018), 12-15 February 2018, Perth, Western Australia p. 142-151
- Full Text:
- Reviewed:
- Description: The potential for stormwater to supplement traditional water supplies from upstream catchments or groundwater is high, with claims that the quantity of additional runoff from impervious surfaces in a modern city in a temperate climate is greater than the total potable water demand. To ensure the success of Integrated Urban Water Management, it must consider the broad context of catchment management and the cumulative effect of all factors including river health. Ballarat, an inland city of approximately 100,000 people in south-eastern Australia, has many attributes necessary to potentially exploit stormwater. Given the doubling of population, tripling of residences and 90% increase in average residence size over the past 60 years, over which time flow data is available for the downstream waterway, it might be expected that the flow in the river downstream of the city within the catchment would reflect additional stormwater runoff. However, no increase in flow was detected between 1957 and 1996 while flow over the past 20 years has reduced by 60%. A water balance shows this decrease was not due to extractions as the stream has been a consistent net receiver of water from other catchments. Modelling data from the Australian Water Resources Assessment indicates that the reduction in streamflow is double what might be expected due to climatic variations. Between 1957 and 1996 there was no significant difference between modelled runoff and actual flow, however from 1997 onwards there is a significant divergence. While lower runoff may be expected during the period of drought, the rainfall-runoff relationship does not return to previous levels during latter years of rainfall. The effect is greater during higher flow months, which has significance when identifying potential additional water resources. Base flow has been reduced to the point where dry weather flow is reliant on waste water treatment plant and mine discharge. This study indicates that while impervious surfaces generate higher runoff which can cause environmental damage, making stormwater an attractive water source, consideration must be given to the impacts on the whole catchment when assessing alternative supply options.
Exploring a flow regime and its historical changes downstream of an urbanised catchment
- Ebbs, David, Dahlhaus, Peter, Barton, Andrew, Kandra, Harpreet
- Authors: Ebbs, David , Dahlhaus, Peter , Barton, Andrew , Kandra, Harpreet
- Date: 2018
- Type: Text , Conference paper
- Relation: 10th International Conference on Water Sensitive Urban Design: Creating water sensitive communities (WSUD 2018 & Hydropolis 2018), Perth, Western Australia p. 131-141
- Full Text:
- Reviewed:
- Description: The rapid growth of Ballarat's urban area, an inland city of approximately 100,000 people in south-eastern Australia, suggests that it is suitable for stormwater capture and reuse. With a threefold increase in the number of dwellings in recent decades, along with a 90% increase in their average size, it should follow that there is evidence of more flow being generated from the urban areas. However, while additional runoff from the growth of impervious areas may be occurring, the overall flow in the receiving river has dramatically reduced with a 60% decrease in the rainfall-runoff relationship since 1997. This reduction in river flow seems disproportionate to any association with the Millennium Drought which occurred during 1997 to 2009. The evidence of river flow has been complicated by other changes in the catchment. A change in the rainfall-runoff relationship has been identified in other similar catchments, and may lead to significant impacts on water resource management over the long term. To better understand the impacts on river flow downstream of an urbanised catchment, the flow has been partitioned into various components over time using the daily stream flow data available from 1957. Base flow, calculated as the stream flow after periods of four or more days without rain, has decreased. Transfers, predominantly from other catchments for use as potable supply and entering the river via the waste water treatment plant, have remained steady, but now make up the vast majority of dry weather flow. While climatic variations have impacted the river significantly the actual streamflow reduction has been twice that predicted by data from the Australian Water Resources Assessment. A significant increase in the number of small farm dams due to the expansion of peri-urban living around Ballarat explains a further portion of the flow reduction. This paper highlights multiple factors which influence river flow and demonstrates how increases in urbanised area do not necessarily create additional river flow at larger aggregate scales. The investigation therefore provides a cautionary tale around assumptions of stormwater harvesting and any perceived benefit to river flow, and provides insights into the importance of collecting water information of the correct type and scale to help inform future integrated urban water management efforts.
- Authors: Ebbs, David , Dahlhaus, Peter , Barton, Andrew , Kandra, Harpreet
- Date: 2018
- Type: Text , Conference paper
- Relation: 10th International Conference on Water Sensitive Urban Design: Creating water sensitive communities (WSUD 2018 & Hydropolis 2018), Perth, Western Australia p. 131-141
- Full Text:
- Reviewed:
- Description: The rapid growth of Ballarat's urban area, an inland city of approximately 100,000 people in south-eastern Australia, suggests that it is suitable for stormwater capture and reuse. With a threefold increase in the number of dwellings in recent decades, along with a 90% increase in their average size, it should follow that there is evidence of more flow being generated from the urban areas. However, while additional runoff from the growth of impervious areas may be occurring, the overall flow in the receiving river has dramatically reduced with a 60% decrease in the rainfall-runoff relationship since 1997. This reduction in river flow seems disproportionate to any association with the Millennium Drought which occurred during 1997 to 2009. The evidence of river flow has been complicated by other changes in the catchment. A change in the rainfall-runoff relationship has been identified in other similar catchments, and may lead to significant impacts on water resource management over the long term. To better understand the impacts on river flow downstream of an urbanised catchment, the flow has been partitioned into various components over time using the daily stream flow data available from 1957. Base flow, calculated as the stream flow after periods of four or more days without rain, has decreased. Transfers, predominantly from other catchments for use as potable supply and entering the river via the waste water treatment plant, have remained steady, but now make up the vast majority of dry weather flow. While climatic variations have impacted the river significantly the actual streamflow reduction has been twice that predicted by data from the Australian Water Resources Assessment. A significant increase in the number of small farm dams due to the expansion of peri-urban living around Ballarat explains a further portion of the flow reduction. This paper highlights multiple factors which influence river flow and demonstrates how increases in urbanised area do not necessarily create additional river flow at larger aggregate scales. The investigation therefore provides a cautionary tale around assumptions of stormwater harvesting and any perceived benefit to river flow, and provides insights into the importance of collecting water information of the correct type and scale to help inform future integrated urban water management efforts.
Elevated levels of herbivory in urban landscapes: Are declines in tree health more than an edge effect?
- Christie, Fiona, Hochuli, Dieter
- Authors: Christie, Fiona , Hochuli, Dieter
- Date: 2005
- Type: Text , Journal article
- Relation: Ecology and Society Vol. 10, no. 1 (2005), p.
- Full Text:
- Reviewed:
- Description: Urbanization is one of the most extreme and rapidly growing anthropogenic pressures on the natural world. Urban development has led to substantial fragmentation of areas of natural habitat, resulting in significant impacts on biodiversity and disruptions to ecological processes. We investigated the levels of leaf damage caused by invertebrates in a dominant canopy species in urban remnants in a highly fragmented urban landscape in Sydney, Australia, by assessing the frequency and extent of chewing and surface damage of leaves in urban remnants compared to the edges and interiors of continuous areas of vegetation. Although no difference was detected in the frequency of leaves showing signs of damage at small, edge, and interior sites, small sites suffered significantly greater levels of leaf damage than did interior sites. Trees at edge sites showed intermediate levels of damage, suggesting that edge effects alone are not the cause of higher levels of herbivory. These findings are the first to demonstrate the effects of urbanization on invertebrate damage in dominant trees at coarse scales. This is consistent with hypotheses predicting that changes in species composition through urban fragmentation affect ecological interactions. Copyright © 2005 by the author(s).
- Authors: Christie, Fiona , Hochuli, Dieter
- Date: 2005
- Type: Text , Journal article
- Relation: Ecology and Society Vol. 10, no. 1 (2005), p.
- Full Text:
- Reviewed:
- Description: Urbanization is one of the most extreme and rapidly growing anthropogenic pressures on the natural world. Urban development has led to substantial fragmentation of areas of natural habitat, resulting in significant impacts on biodiversity and disruptions to ecological processes. We investigated the levels of leaf damage caused by invertebrates in a dominant canopy species in urban remnants in a highly fragmented urban landscape in Sydney, Australia, by assessing the frequency and extent of chewing and surface damage of leaves in urban remnants compared to the edges and interiors of continuous areas of vegetation. Although no difference was detected in the frequency of leaves showing signs of damage at small, edge, and interior sites, small sites suffered significantly greater levels of leaf damage than did interior sites. Trees at edge sites showed intermediate levels of damage, suggesting that edge effects alone are not the cause of higher levels of herbivory. These findings are the first to demonstrate the effects of urbanization on invertebrate damage in dominant trees at coarse scales. This is consistent with hypotheses predicting that changes in species composition through urban fragmentation affect ecological interactions. Copyright © 2005 by the author(s).
- «
- ‹
- 1
- ›
- »