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Herbicide efficacy for aquatic Alternanthera philoxeroides management in an early stage of invasion : Integrating above-ground biomass, below-ground biomass and viable stem fragmentation

- Clements, Daniel, Dugdale, Tony, Butler, Kym, Florentine, Singarayer, Sillitoe, Jim

  • Authors: Clements, Daniel , Dugdale, Tony , Butler, Kym , Florentine, Singarayer , Sillitoe, Jim
  • Date: 2017
  • Type: Text , Journal article
  • Relation: Weed Research Vol. 57, no. 4 (2017), p. 257-266
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  • Description: Alternanthera philoxeroides is a problematic invasive plant in many regions of the world that is difficult to control once naturalised. It poses a threat to agricultural productivity, biodiversity and social amenity values of aquatic environments. Significant research has been conducted internationally, regarding the efficacy of different herbicides for control of A. philoxeroides. However, no studies have looked at key aspects of control for effective management in an early stage of invasion of aquatic environments, hindering eradication and control programmes. This study evaluates the efficacy of herbicides and surfactants on key A. philoxeroides response metrics, including control of above-ground biomass, below-ground biomass and production of viable stem fragments. This study concluded that glyphosate (isopropylamine salt) minimises viable stem fragment production post-herbicide application, compared with imazapyr and metsulfuron, thus reducing the potential for dispersal throughout catchments and waterways. In contrast, imazapyr and metsulfuron provided more effective control than glyphosate for A. philoxeroides growing on exposed embankments. We propose that an effective management strategy for early invasion of aquatic A. philoxeroides, using herbicides, would be to conduct initial applications of glyphosate to control overwater biomass and limit dispersal of viable stem fragments. Once infestations have been forced back to the embankment, imazapyr or metsulfuron treatments will provide longer term control. © 2017 European Weed Research Society

Application of soft computing in predicting rock fragmentation to reduce environmental blasting side effects

- Monjezi, Masoud, Mohamadi, Hasan, Barati, Bahare, Khandelwal, Manoj

  • Authors: Monjezi, Masoud , Mohamadi, Hasan , Barati, Bahare , Khandelwal, Manoj
  • Date: 2014
  • Type: Text , Journal article
  • Relation: Arabian Journal of Geosciences Vol. 7, no. 2 (2014), p. 505-511
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  • Description: In the blasting operation, risk of facing with undesirable environmental phenomena such as ground vibration, air blast, and flyrock is very high. Blasting pattern should properly be designed to achieve better fragmentation to guarantee the successfulness of the process. A good fragmentation means that the explosive energy has been applied in a right direction. However, many studies indicate that only 20-30 % of the available energy is actually utilized for rock fragmentation. Involvement of various effective parameters has made the problem complicated, advocating application of new approaches such as artificial intelligence-based techniques. In this paper, artificial neural network (ANN) method is used to predict rock fragmentation in the blasting operation of the Sungun copper mine, Iran. The predictive model is developed using eight and three input and output parameters, respectively. Trying various types of the networks, it was found that a trained model with back-propagation algorithm having architecture 8-15-8-3 is the optimum network. Also, performance comparison of the ANN modeling with that of the statistical method was confirmed robustness of the neural networks to predict rock fragmentation in the blasting operation. Finally, sensitivity analysis showed that the most influential parameters on fragmentation are powder factor, burden, and bench height. © 2012 Saudi Society for Geosciences.

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.
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  • 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.

Dietary characteristics of Emus (Dromaius novaehollandiae) in semi-arid New South Wales, Australia, and dispersal and germination of ingested seeds

- Dunstan, Heath, Florentine, Singarayer, Calvino-Cancela, Maria, Westbrooke, Martin, Palmer, Grant

  • Authors: Dunstan, Heath , Florentine, Singarayer , Calvino-Cancela, Maria , Westbrooke, Martin , Palmer, Grant
  • Date: 2013
  • Type: Text , Journal article
  • Relation: Emu Vol. 113, no. 2 (2013), p. 168-176
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  • Description: The Emu (Dromaius novaehollandiae) eats a wide range of seeds and other plant material but little is known of the seeds eaten and dispersed in arid Australia. This study aimed to determine the species of seed and fruits eaten by Emus through the year and investigate the effect of the passage of seeds through the Emu gut on seed germination. Emu scats were opportunistically collected in all seasons of 2005 at Nanya Research Station, western New South Wales. Seeds of 29 plant species were retrieved, identified and counted from 221 scats. Seeds of perennial species, such as Belah (Casuarina pauper), Ruby Saltbush (Enchylaena tomentosa), Common Emu-bush (Eremophila glabra) and Nitre-bush (Nitraria billardierei), predominated. Seed composition of scats was more diverse in summer than in winter, autumn and spring. Seeds of Common Emu-bush, Berrigan (Eremophila longifolia) and Sweet Quandong (Santalum acuminatum) showed no germination after passage through the gut. Ruby Saltbush and Nitre-bush showed very low germination rates. The Emu is a generalist feeder, capable of ingesting and dispersing large numbers of plant species. Through high seed consumption and long gut-retention time, Emus could potentially play a significant role in long-distance dispersal of seeds and, through such dispersal, in the vegetation dynamics of arid Australia. © 2013 Bird Life Australia.
  • Description: 2003011097

Thermal fragmentation as a possible, viable, alternative mining method in narrow vein mining?

- Bouwmeester, Patrick, Tuck, Michael, Koroznikova, Larissa, Durkin, Steve

  • Authors: Bouwmeester, Patrick , Tuck, Michael , Koroznikova, Larissa , Durkin, Steve
  • Date: 2020
  • Type: Text , Journal article
  • Relation: Mining, Metallurgy and Exploration Vol. 37, no. 2 (2020), p. 605-618
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  • Description: In currently used mining methods, blasting techniques often causes dilution of valuable ore and results in costly processing requirements. In the context of narrow vein mining of thin and highly concentrated orebodies there is a need of a mining method that can reduce dilution in order to remain economically viable. This research project explored the viability of a new mining technology, thermal fragmentation, in narrow vein mining. Thermal fragmentation technology uses a flame jet to produce extreme heat that spalls the surrounding rock to a strategically located drill hole, as an alternative to traditional blasting. This paper creates a net present value (NPV) model of a mining method using thermal fragmentation, as well as for an existing method used for narrow vein mining; comparisons and evaluations were made regarding the feasibility of the new technology. It was found that while overall costs for thermal fragmentation were relatively high, reductions in wages, haulage and processing costs, as well as increased productivity and ore recovery, meant that the new method would improve the financial performance of any operation. These results identify that there is an opportunity to introduce the thermal fragmentation technology to narrow vein mines within Australia, in order to lower costs and increase profit. © 2019, Society for Mining, Metallurgy & Exploration Inc.

Comparison and application of top and bottom air decks to improve blasting operations

- Monjezi, Monjezi, Amiri, Hamed, Mousavi, Mir, Hamidi, Jafar, Khandelwal, Manoj

  • Authors: Monjezi, Monjezi , Amiri, Hamed , Mousavi, Mir , Hamidi, Jafar , Khandelwal, Manoj
  • Date: 2022
  • Type: Text , Journal article
  • Relation: Aims Geosciences Vol. 9, no. 1 (2022), p. 16-33
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  • Description: The blasting operation is an integral part of mines, and it is still being used as the most economical tool to fragment and displace rock mass. Appropriate blast optimization alleviates undesirable side effects, such as ground vibration, air blasts and flyrock, and it and enhances rock fragmentation. Blast optimization can also be effective in reducing the overall mining cost. One way of reducing blasting side effects is to use deck charges instead of continuous ones. The location of the deck(s) is still considered an unanswered question for many researchers. In this study, an investigation was carried out to find an appropriate air deck position(s) within the blast hole. For this, air decks were placed at three different positions (top, middle and bottom) within a blast hole at Cheshmeh-Parvar gypsum and Chah-Gaz iron ore mines to understand and evaluate air deck location impact on blast fragmentation and blast nuisances. The results were compared based on the existing blasting practices at both mines, as well as the air-deck blasting results. The results obtained from the blasting were very satisfactory; it was found that charging with a top air deck, as compared to current blasting practices, causes a decrement in the specific charge, as well as a decrement of 38% in the back break and 50% in flyrock; the average size of fragments obtained from blasting was increased by 26%. Thus, it can be said that the top air deck is more advantageous than the bottom air deck in terms of reducing undesired blasting consequences.

Climate drying amplifies the effects of land-use change and interspecific interactions on birds

- Bennett, Joanne, Clarke, Rohan, Horrocks, Gregory, Thomson, James, Mac Nally, Ralph

  • Authors: Bennett, Joanne , Clarke, Rohan , Horrocks, Gregory , Thomson, James , Mac Nally, Ralph
  • Date: 2015
  • Type: Text , Journal article
  • Relation: Landscape Ecology Vol. 30, no. 10 (2015), p. 2031-2043
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  • Description: Context: Climate change may amplify the effects of land-use change, including induced changes in interspecific interactions. Objectives: To investigate whether an avifauna changed over a period of severe drought, and if changes in avifaunas were related to changes in vegetation characteristics and the irruption of a despotic native species, the noisy miner Manorina melanocephala. Methods: In the box–ironbark forests of south-eastern Australia, we resurveyed the avifaunas and remeasured vegetation characteristics in 120 forest transects in 2010–2011 that had previously been measured in 1995–1997. Results: The avifauna changed markedly over the prolonged drought, and changes were more marked in smaller fragments of remnant vegetation in which more pronounced vegetation change had occurred. The noisy miner increased differentially in smaller remnants adding to the declines, especially for small-bodied birds. Conclusions: Long droughts interspersed with short wet periods are projected for the region, so the imposition of climate effects on an already much-modified region has profound implications for the avifauna. The noisy miner has (and continues) to benefit from both land-use and climate change, so future sequences of drought interspersed with short wet periods are likely to lead to further changes in the avifauna as the miner extends its occupancy. Differential reductions in small nectarivores and insectivores will affect ecosystem processes, including the control of defoliating insects, seed dispersal and pollination. © 2015, Springer Science+Business Media Dordrecht.

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.
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  • 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).

Biodiversity and status of butterflies in the Ballarat Region, Victoria

- Ambrose, Graeme

  • Authors: Ambrose, Graeme
  • Date: 2005
  • Type: Text , Journal article
  • Relation: Victorian Naturalist Vol. 122, no. 1 (2005), p. 21-34
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  • Description: The butterfly fauna of the Ballarat Vic region is not well known, reflecting a lack of comprehensive surveys. The characteristics of the Ballarat region are described and butterfly species found locally are documented. Some 45 species from five families and 31 genera are now known for the region, including one introduced species. Management issues include habitat fragmentation and degradation. Some species are insufficiently known in the region to permit the development of management strategies (A).
  • Description: 2003001059

Sensitivity analysis on blast design parameters to improve bench blasting outcomes using the Taguchi method

- Hosseini, Mostafa, Khandelwal, Manoj, Lotfi, Rahman, Eslahi, Mohsen

  • Authors: Hosseini, Mostafa , Khandelwal, Manoj , Lotfi, Rahman , Eslahi, Mohsen
  • Date: 2023
  • Type: Text , Journal article
  • Relation: Geomechanics and Geophysics for Geo-Energy and Geo-Resources Vol. 9, no. 1 (2023), p.
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  • Description: In surface mines, bench blasting is a typical way of excavating hard rock mass. Although a significant development has taken place in explosive technology but still only a part of the energy is used to excavate and a large proportion of energy is wasted away and creates a number of nuisances. Backbreak, massive rock fragmentation, and high-intensity ground vibration are all symptoms of improper blasting. As a result, production costs increase significantly while productivity decreases. The blasting outcomes are affected by a variety of factors, which may be classified into three categories: rock properties, explosive properties, and blast geometry. Consequently, it is necessary to examine the effect of these parameters on bench blasting. So, in this study, a sensitivity analysis has been performed on various blast design parameters using the Taguchi method to study the influence of blast design parameters on blast vibration, backbreak, and rock fragmentation. A total of 32 experiments have been designed and numerical modeling was also carried out, using LS DYNA software to simulate the blast results. It was found that the blast hole diameter is the most important factor influencing the blasting outcomes. However, the number of rows in a blast affects backbreak almost slightly more than the hole diameter, but blast vibrations and the surrounding rock damage strongly depend on the hole diameter. Furthermore, rock blast geometry significantly affected rock blast vibration and damage compared to explosive properties. However, both blast geometry parameters and explosive properties play a significant role in backbreaking. © 2023, The Author(s).

Application of thermal fragmentation in Australian hard rock underground narrow-vein mining

- Drake, Bradley, Koroznikova, Larissa, Tuck, Michael, Durkin, Steve

  • Authors: Drake, Bradley , Koroznikova, Larissa , Tuck, Michael , Durkin, Steve
  • Date: 2020
  • Type: Text , Journal article
  • Relation: Mining, Metallurgy and Exploration Vol. 37, no. 1 (2020), p. 219-229
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  • Description: This paper presents the results from the investigation of the application of thermal fragmentation in Australian hard rock underground narrow-vein mining. Two geologically similar samples from an underground narrow-vein hard rock gold mine were collected to obtain a measure of the technology’s ability to recover ore by the creation of large thermal openings to assess the applicability of the thermal method. Particle size distribution showed a higher generation of fine product, − 2 mm, by thermal fragmentation compared with selective blasting by 31%. The Bond work index for thermal ore (12.62 kWh/t) is half to that of the blasted ore value (25.32 kWh/t). The average grindability obtained for the thermal ore sample was greater than the blasted sample by a factor of 2.44, a higher value indicating a decrease in the energy required to grind. The thermal fragmentation method generates product with higher dissolution of gold in cyanide, by 14% for the − 9.5 + 2 mm size fraction samples. Additionally, the thermal fragmentation results in higher production of − 9.5 + 2 mm material by 15 % compared with selective blasting. © 2019, Society for Mining, Metallurgy & Exploration Inc.

Mine-to-crusher policy : planning of mine blasting patterns for environmentally friendly and optimum fragmentation using Monte Carlo simulation-based multi-objective grey wolf optimization approach

- Hosseini, Shahab, Mousavi, Amin, Monjezi, Masoud, Khandelwal, Manoj

  • Authors: Hosseini, Shahab , Mousavi, Amin , Monjezi, Masoud , Khandelwal, Manoj
  • Date: 2022
  • Type: Text , Journal article
  • Relation: Resources Policy Vol. 79, no. (2022), p.
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  • Description: The quality of rock fragmentation intensively affects downstream operations and operational costs. Besides, Environmental side effects are inevitable due to mine blasting despite improvements in blasting consequences such as fly-rock and back-break. This study concentrates on optimizing mine blasting patterns for environmentally friendly mineral production and minimizing operational costs by achieving environmental-oriented and economic objectives-based on a new framework using artificial intelligence techniques. A gene expression programming (GEP) based on Monte Carlo simulations (MCs) denoted that rock size distribution can be modeled and predicted without any uncertainty. Four main objectives involving operational costs, back-break, fly-rock, and toe volume were highlighted for minimizing in the optimization framework. The multi-objective model was implemented by applying it to a running mine and solved using the grey wolf optimization algorithm. As optimizing, 17 optimal blasting plans were achieved to implement in the different rock types. The multi-objective model was able to reduce mine to crusher cost as well as undesirable blasting consequences considerable favourite of mining managers. © 2022 Elsevier Ltd
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