Construction of super edge magic total graphs
- Xie, Wei, Sugeng, Kiki Ariyanti
- Authors: Xie, Wei , Sugeng, Kiki Ariyanti
- Date: 2005
- Type: Text , Conference paper
- Relation: Paper presented at the Sixteenth Australasian Workshop on Combinatorial Algorithms, 18-21 September 2005, Ballarat, Australia, Ballarat, Victoria : 18th September, 2005
- Full Text:
- Reviewed:
- Description: E1
- Description: 2003001433
- Authors: Xie, Wei , Sugeng, Kiki Ariyanti
- Date: 2005
- Type: Text , Conference paper
- Relation: Paper presented at the Sixteenth Australasian Workshop on Combinatorial Algorithms, 18-21 September 2005, Ballarat, Australia, Ballarat, Victoria : 18th September, 2005
- Full Text:
- Reviewed:
- Description: E1
- Description: 2003001433
Ant community responses to farmland use and revegetation in a fragmented agricultural landscape
- Ng, Katherine, Nowrouzi, Somayeh, Staunton, Kyran, Barton, Philip, Driscoll, Don
- Authors: Ng, Katherine , Nowrouzi, Somayeh , Staunton, Kyran , Barton, Philip , Driscoll, Don
- Date: 2021
- Type: Text , Journal article
- Relation: Agriculture Ecosystems & Environment Vol. 311, no. (May 2021), p. 8
- Full Text: false
- Reviewed:
- Description: Recent alarming losses of insects from agricultural landscapes in multiple countries around the world have brought into sharp focus the urgent need to identify ways to manage these landscapes to avoid further biodiversity decline. Identifying the drivers of insect declines, such as land use change, is critical to this effort. We examined ant communities at the interface between remnant vegetation patches and three adjoining farmland types (wheat crop, rested from cropping and restoration plantings) in a fragmented landscape in temperate Australia. We asked: do ant communities and occurrence of individual species differ between remnant patches and farmlands with more intensive farmland use (restoration plantings < rested farmlands < wheat crop)? We recorded 13,283 ants belonging to 102 species from 30 genera. Excluding 21 singletons, 27 species only occurred in remnant patches compared to ten species found only in farmlands. Ant community composition in wheat crop and rested farmlands significantly differed from their adjacent remnant patches and were more homogeneous. In contrast, ant communities from restoration plantings in farmland were not significantly different in composition from those in the adjacent remnant patch. The large, aggressive Australian meat ant (Iridomyrmex purpureus) showed significantly higher occurrence in the remnant patch than all farmland types, and we suggest that the absence of this strongly interacting species from farmlands may have contributed to biotic homogenisation. Our findings show that native vegetation provides crucial habitat resources for many ant species that are not provided by farmlands, and native plantings can, in some cases, ameliorate negative effects of farmland clearing over relatively short time scales (<7 years). Agricultural intensification that involves loss of remnant native vegetation or reduced revegetation will contribute to ongoing losses and changes to ant biodiversity in farming landscapes. However, replanting native vegetation can lead to rapid restoration, signifying a possible simple remedy to insect declines.
- Ng, Katherine, Nowrouzi, Somayeh, Staunton, Kyran, Barton, Philip, Driscoll, Don
- Authors: Ng, Katherine , Nowrouzi, Somayeh , Staunton, Kyran , Barton, Philip , Driscoll, Don
- Date: 2021
- Type: Text , Journal article
- Relation: Agriculture, Ecosystems and Environment Vol. 311, no. (2021), p.
- Full Text: false
- Reviewed:
- Description: Recent alarming losses of insects from agricultural landscapes in multiple countries around the world have brought into sharp focus the urgent need to identify ways to manage these landscapes to avoid further biodiversity decline. Identifying the drivers of insect declines, such as land use change, is critical to this effort. We examined ant communities at the interface between remnant vegetation patches and three adjoining farmland types (wheat crop, rested from cropping and restoration plantings) in a fragmented landscape in temperate Australia. We asked: do ant communities and occurrence of individual species differ between remnant patches and farmlands with more intensive farmland use (restoration plantings < rested farmlands < wheat crop)? We recorded 13,283 ants belonging to 102 species from 30 genera. Excluding 21 singletons, 27 species only occurred in remnant patches compared to ten species found only in farmlands. Ant community composition in wheat crop and rested farmlands significantly differed from their adjacent remnant patches and were more homogeneous. In contrast, ant communities from restoration plantings in farmland were not significantly different in composition from those in the adjacent remnant patch. The large, aggressive Australian meat ant (Iridomyrmex purpureus) showed significantly higher occurrence in the remnant patch than all farmland types, and we suggest that the absence of this strongly interacting species from farmlands may have contributed to biotic homogenisation. Our findings show that native vegetation provides crucial habitat resources for many ant species that are not provided by farmlands, and native plantings can, in some cases, ameliorate negative effects of farmland clearing over relatively short time scales (<7 years). Agricultural intensification that involves loss of remnant native vegetation or reduced revegetation will contribute to ongoing losses and changes to ant biodiversity in farming landscapes. However, replanting native vegetation can lead to rapid restoration, signifying a possible simple remedy to insect declines. © 2021 Elsevier B.V.
Birds as surrogates for mammals and reptiles: Are patterns of cross-taxonomic associations stable over time in a human-modified landscape?
- Yong, Ding, Barton, Philip, Okada, Sachiko, Crane, Mason, Lindenmayer, David
- Authors: Yong, Ding , Barton, Philip , Okada, Sachiko , Crane, Mason , Lindenmayer, David
- Date: 2016
- Type: Text , Journal article
- Relation: Ecological Indicators Vol. 69, no. (2016), p. 152-164
- Full Text:
- Reviewed:
- Description: Cross-taxonomic surrogates can be feasible alternatives to direct measurements of biodiversity in conservation if validated with robust data and used with explicit goals. However, few studies of cross-taxonomic surrogates have examined how temporal changes in composition or richness in one taxon can drive variation in concordant patterns of diversity in another taxon, particularly in a dynamic and heavily modified landscape. We examined this problem by assessing changes in cross-taxonomic associations over time between the surrogate (birds) and target vertebrate taxa (mammals, reptiles) that demand high sampling effort, in a heterogeneous mosaic landscape comprising pine monoculture, eucalypt woodland remnants and agricultural land. Focussing on four study years (1999, 2001, 2011, 2013) from a dataset collected over 15 years, we: (1) investigated temporal changes in cross-taxonomic congruency among three animal taxa (2) explored how temporal variation in composition and species richness of each taxon might account for variation in cross-taxonomic congruency, and (3) identified habitat structural variables that are strongly correlated with species composition of each taxon. We found the strength of cross-taxonomic congruency varied between taxa in response to both landscape context and over time. Among the three taxa, overall correlations were weak but were consistently positive and strongest between birds and mammals, while correlations involving reptiles were usually weak and negative. We also found that stronger species richness and composition correlations between birds and mammals were not only more prevalent in woodland remnants in the agricultural matrix, but they also increased in strength over time. Temporal shifts in species composition differed in rate and extent among the taxa even though these shifts were significant over time, while important habitat structural correlates were seldom shared across taxa. Our study highlights the role of the landscape matrix and time in shaping animal communities and the resulting cross-taxonomic associations in the woodland remnants, especially after a major perturbation event (i.e. plantation establishment). In such dynamic landscapes, differing and taxon-specific shifts in species diversity over time can influence the strength, direction and consistency of cross-taxonomic correlations, therefore posing a 'temporal' problem for the use of surrogates like birds in monitoring and assessment of biodiversity, and conservation management practices in general. © 2016 Elsevier Ltd. All rights reserved.
- Authors: Yong, Ding , Barton, Philip , Okada, Sachiko , Crane, Mason , Lindenmayer, David
- Date: 2016
- Type: Text , Journal article
- Relation: Ecological Indicators Vol. 69, no. (2016), p. 152-164
- Full Text:
- Reviewed:
- Description: Cross-taxonomic surrogates can be feasible alternatives to direct measurements of biodiversity in conservation if validated with robust data and used with explicit goals. However, few studies of cross-taxonomic surrogates have examined how temporal changes in composition or richness in one taxon can drive variation in concordant patterns of diversity in another taxon, particularly in a dynamic and heavily modified landscape. We examined this problem by assessing changes in cross-taxonomic associations over time between the surrogate (birds) and target vertebrate taxa (mammals, reptiles) that demand high sampling effort, in a heterogeneous mosaic landscape comprising pine monoculture, eucalypt woodland remnants and agricultural land. Focussing on four study years (1999, 2001, 2011, 2013) from a dataset collected over 15 years, we: (1) investigated temporal changes in cross-taxonomic congruency among three animal taxa (2) explored how temporal variation in composition and species richness of each taxon might account for variation in cross-taxonomic congruency, and (3) identified habitat structural variables that are strongly correlated with species composition of each taxon. We found the strength of cross-taxonomic congruency varied between taxa in response to both landscape context and over time. Among the three taxa, overall correlations were weak but were consistently positive and strongest between birds and mammals, while correlations involving reptiles were usually weak and negative. We also found that stronger species richness and composition correlations between birds and mammals were not only more prevalent in woodland remnants in the agricultural matrix, but they also increased in strength over time. Temporal shifts in species composition differed in rate and extent among the taxa even though these shifts were significant over time, while important habitat structural correlates were seldom shared across taxa. Our study highlights the role of the landscape matrix and time in shaping animal communities and the resulting cross-taxonomic associations in the woodland remnants, especially after a major perturbation event (i.e. plantation establishment). In such dynamic landscapes, differing and taxon-specific shifts in species diversity over time can influence the strength, direction and consistency of cross-taxonomic correlations, therefore posing a 'temporal' problem for the use of surrogates like birds in monitoring and assessment of biodiversity, and conservation management practices in general. © 2016 Elsevier Ltd. All rights reserved.
Contrasting beetle assemblage responses to cultivated farmlands and native woodlands in a dynamic agricultural landscape
- Ng, Katherina, Driscoll, Don, MacFadyen, Sarina, Barton, Philip, McIntyre, Sue, Lindenmayer, David
- Authors: Ng, Katherina , Driscoll, Don , MacFadyen, Sarina , Barton, Philip , McIntyre, Sue , Lindenmayer, David
- Date: 2017
- Type: Text , Journal article
- Relation: Ecosphere Vol. 8, no. 12 (2017), p.
- Full Text:
- Reviewed:
- Description: There is an urgent need to identify ways of managing agricultural landscapes for biodiversity conservation without reducing food production. Farming practices that consider spatiooral heterogeneity of farm fields may be a feasible alternative to large-scale revegetation of farmlands for maintaining arthropod biodiversity and their important ecological function. We examined seasonal differences in beetle assemblages in woodland remnants and four adjoining farmland uses in a highly modified agricultural landscape in southeastern Australia. The farmland uses were crops, fallows, and two restoration treatments (fine woody debris applied over harvested crop fields, and restoration plantings). Unexpectedly, overall species richness was significantly lower in remnants than in adjacent farmlands. Remnants and farmlands supported significantly different assemblages, with a third of species found in both habitats. Abundance responses were taxon-specific and influenced by interactions between land use and season. In particular, predator abundance was significantly higher in plantings and fallows during spring compared to summer. Detritivore abundance was significantly higher in the woody debris compared to the adjacent remnants. Herbivore abundance did not differ between remnants and farmlands over time. Complex responses provide strong support for a mosaic of land uses to effectively conserve different beetle groups. Species richness results suggest that further agricultural intensification, in farm fields and through the removal of remnant vegetation, risks reducing beetle diversity in this region. Maintaining farmland heterogeneity with a mix of low-intensity land uses, such as conservation tillage, crop-fallow rotation, restoration plantings, and the novel application of fine woody debris over cultivated fields, may provide seasonal refuge and resources for beetles. © 2017 Ng et al.
- Authors: Ng, Katherina , Driscoll, Don , MacFadyen, Sarina , Barton, Philip , McIntyre, Sue , Lindenmayer, David
- Date: 2017
- Type: Text , Journal article
- Relation: Ecosphere Vol. 8, no. 12 (2017), p.
- Full Text:
- Reviewed:
- Description: There is an urgent need to identify ways of managing agricultural landscapes for biodiversity conservation without reducing food production. Farming practices that consider spatiooral heterogeneity of farm fields may be a feasible alternative to large-scale revegetation of farmlands for maintaining arthropod biodiversity and their important ecological function. We examined seasonal differences in beetle assemblages in woodland remnants and four adjoining farmland uses in a highly modified agricultural landscape in southeastern Australia. The farmland uses were crops, fallows, and two restoration treatments (fine woody debris applied over harvested crop fields, and restoration plantings). Unexpectedly, overall species richness was significantly lower in remnants than in adjacent farmlands. Remnants and farmlands supported significantly different assemblages, with a third of species found in both habitats. Abundance responses were taxon-specific and influenced by interactions between land use and season. In particular, predator abundance was significantly higher in plantings and fallows during spring compared to summer. Detritivore abundance was significantly higher in the woody debris compared to the adjacent remnants. Herbivore abundance did not differ between remnants and farmlands over time. Complex responses provide strong support for a mosaic of land uses to effectively conserve different beetle groups. Species richness results suggest that further agricultural intensification, in farm fields and through the removal of remnant vegetation, risks reducing beetle diversity in this region. Maintaining farmland heterogeneity with a mix of low-intensity land uses, such as conservation tillage, crop-fallow rotation, restoration plantings, and the novel application of fine woody debris over cultivated fields, may provide seasonal refuge and resources for beetles. © 2017 Ng et al.
Remnant vegetation, plantings and fences are beneficial for reptiles in agricultural landscapes
- Pulsford, Stephanie, Driscoll, Don, Barton, Philip, Lindenmayer, David
- Authors: Pulsford, Stephanie , Driscoll, Don , Barton, Philip , Lindenmayer, David
- Date: 2017
- Type: Text , Journal article
- Relation: Journal of Applied Ecology Vol. 54, no. 6 (2017), p. 1710-1719
- Full Text:
- Reviewed:
- Description: Managing agricultural landscapes for biodiversity conservation is increasingly difficult as land use is modified or intensified for production. Finding ways to mitigate the negative effects of agriculture on biodiversity is therefore critical. We asked the question: How do remnant patches, paddock types and grazing regimes influence reptile assemblages in a grazing landscape? At 12 sites, we surveyed reptiles and environmental covariates in remnant woodland patches and in four paddock types: (i) grazed pasture, (ii) linear plantings, (iii) coarse woody debris (CWD) added to grazed pasture and (iv) fences between grazed pasture. Each site was either continuously or rotationally grazed. Remnant vegetation and other vegetation attributes such as tree cover and leaf litter greatly influenced reptiles. We recorded higher reptile abundance and species richness in areas with more tree cover and leaf litter. For rare species (captured in ≤4 sites <70 captures), there were 5·7 more animals and 2·6 more species in sites with 50% woody cover within 3 km compared to 5% woody cover. The abundance and richness of rare species, and one common species differed between paddock types and were higher in linear plantings and fence transects compared to CWD and pasture transects. Synthesis and applications. Grazed paddocks, particularly those with key features such as fences and plantings can provide habitat for reptiles. This suggests that discrete differentiation between patch and matrix does not apply for reptiles in these systems. Management to promote reptile conservation in agricultural landscapes should involve protecting existing remnant vegetation, regardless of amount; and promote key habitat features of trees, leaf litter and shrubs. Establishing plantings and fences is important as they support high numbers of less common reptiles and may facilitate reptiles to move through and use greater amounts of the landscape. © 2017 The Authors. Journal of Applied Ecology © 2017 British Ecological Society
- Authors: Pulsford, Stephanie , Driscoll, Don , Barton, Philip , Lindenmayer, David
- Date: 2017
- Type: Text , Journal article
- Relation: Journal of Applied Ecology Vol. 54, no. 6 (2017), p. 1710-1719
- Full Text:
- Reviewed:
- Description: Managing agricultural landscapes for biodiversity conservation is increasingly difficult as land use is modified or intensified for production. Finding ways to mitigate the negative effects of agriculture on biodiversity is therefore critical. We asked the question: How do remnant patches, paddock types and grazing regimes influence reptile assemblages in a grazing landscape? At 12 sites, we surveyed reptiles and environmental covariates in remnant woodland patches and in four paddock types: (i) grazed pasture, (ii) linear plantings, (iii) coarse woody debris (CWD) added to grazed pasture and (iv) fences between grazed pasture. Each site was either continuously or rotationally grazed. Remnant vegetation and other vegetation attributes such as tree cover and leaf litter greatly influenced reptiles. We recorded higher reptile abundance and species richness in areas with more tree cover and leaf litter. For rare species (captured in ≤4 sites <70 captures), there were 5·7 more animals and 2·6 more species in sites with 50% woody cover within 3 km compared to 5% woody cover. The abundance and richness of rare species, and one common species differed between paddock types and were higher in linear plantings and fence transects compared to CWD and pasture transects. Synthesis and applications. Grazed paddocks, particularly those with key features such as fences and plantings can provide habitat for reptiles. This suggests that discrete differentiation between patch and matrix does not apply for reptiles in these systems. Management to promote reptile conservation in agricultural landscapes should involve protecting existing remnant vegetation, regardless of amount; and promote key habitat features of trees, leaf litter and shrubs. Establishing plantings and fences is important as they support high numbers of less common reptiles and may facilitate reptiles to move through and use greater amounts of the landscape. © 2017 The Authors. Journal of Applied Ecology © 2017 British Ecological Society
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