A global review on arid zone restoration : approaches and challenges
- Stapleton, Joseph, Bates, Sarah, Lewis, Megan, Turner, Shane, Warne, David, Florentine, Singarayer
- Authors: Stapleton, Joseph , Bates, Sarah , Lewis, Megan , Turner, Shane , Warne, David , Florentine, Singarayer
- Date: 2024
- Type: Text , Journal article , Review
- Relation: Restoration Ecology Vol. 32, no. 6 (2024), p.
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- Description: Arid environments have become degraded in recent times through human activity highlighting the need for restoration works to reverse this trend. One of the most common forms of restoration works is revegetation. However, revegetation is difficult in the arid zone due to a combination of environmental factors such as low moisture and extreme temperatures, as well as financial and administrative factors. In this review, we investigated the literature describing various methods available for arid revegetation, and assess their utility for revegetation activities. Each of the methods investigated were found to have potential advantages and disadvantages, though some general trends were observed. Two main planting methods were identified, “out-planting” and “direct seeding.” Which of these methods to use depends on the conditions of the project being undertaken. Out-planting appeared to be the most suited approach to smaller scale projects with higher budget availability, whereas direct seeding was more suited to large scale, lower budget projects. Weed control prior to planting was identified as being critical for success in most works, whereas soil ripping was beneficial for direct seeding projects. Among the soil amendments investigated, water-holding gels were most likely to be beneficial, whereas fertilizers were riskier due to their potential to reduce drought tolerance and increase weed invasion. Microbial inoculation with mycorrhiza showed high potential to improve plant performance but may be held back by the lack of suitable commercial sources. Newer seed technologies, such as synthetic seed coats and pellets, show promise, but this issue still requires further research and development. © 2023 The Authors. Restoration Ecology published by Wiley Periodicals LLC on behalf of Society for Ecological Restoration.
- Authors: Stapleton, Joseph , Bates, Sarah , Lewis, Megan , Turner, Shane , Warne, David , Florentine, Singarayer
- Date: 2024
- Type: Text , Journal article , Review
- Relation: Restoration Ecology Vol. 32, no. 6 (2024), p.
- Full Text:
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- Description: Arid environments have become degraded in recent times through human activity highlighting the need for restoration works to reverse this trend. One of the most common forms of restoration works is revegetation. However, revegetation is difficult in the arid zone due to a combination of environmental factors such as low moisture and extreme temperatures, as well as financial and administrative factors. In this review, we investigated the literature describing various methods available for arid revegetation, and assess their utility for revegetation activities. Each of the methods investigated were found to have potential advantages and disadvantages, though some general trends were observed. Two main planting methods were identified, “out-planting” and “direct seeding.” Which of these methods to use depends on the conditions of the project being undertaken. Out-planting appeared to be the most suited approach to smaller scale projects with higher budget availability, whereas direct seeding was more suited to large scale, lower budget projects. Weed control prior to planting was identified as being critical for success in most works, whereas soil ripping was beneficial for direct seeding projects. Among the soil amendments investigated, water-holding gels were most likely to be beneficial, whereas fertilizers were riskier due to their potential to reduce drought tolerance and increase weed invasion. Microbial inoculation with mycorrhiza showed high potential to improve plant performance but may be held back by the lack of suitable commercial sources. Newer seed technologies, such as synthetic seed coats and pellets, show promise, but this issue still requires further research and development. © 2023 The Authors. Restoration Ecology published by Wiley Periodicals LLC on behalf of Society for Ecological Restoration.
A review of the biology, distribution, and management challenges posed by the invasive weed Ziziphus mauritiana L., with special reference to its invasion in Australia
- Roberts, Jason, Dhileepan, Kunjithapatham, Florentine, Singarayer
- Authors: Roberts, Jason , Dhileepan, Kunjithapatham , Florentine, Singarayer
- Date: 2024
- Type: Text , Journal article , Review
- Relation: Weed Research Vol. 64, no. 1 (2024), p. 8-18
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- Description: Ziziphus mauritiana is an economically detrimental and environmentally destructive plant in non-native areas where it has escaped cultivation. It forms dense, impenetrable thickets that restrict the movement of livestock across the landscape and has the capacity to alter various ecological functions at the site of invasion, all of which contribute towards land degradation and the reduction of economic profitability. Although there are several management strategies implemented to control Z. mauritiana, it is clear that no single-method approach will effectively control the species in the long-term. Whilst chemical and mechanical methods appear to show promising results, they tend to be restricted to areas that are easily accessible and, even so, can be challenging and laborious to treat evenly across dense thicket areas. Several prospective biological control agents have been identified for Z. mauritiana, although further investigations are required to ascertain the host specificity, and to explore and identify their climatic and environmental suitability of host specific agents for release in non-native regions. Ecological burning alone is not effective in controlling Z. mauritiana and will likely increase its emergence. As such, it could be adopted as part of an integrated management approach to assist other methods for long-term control, but again the development of such an approach requires further investigation. To contribute towards the control of Z. mauritiana, this review explores its biology, distribution and management challenges whilst identifying areas of research that will assist in the long-term and confident control of the species, with an emphasis on its invasion in Australia. © 2024 The Authors. Weed Research published by John Wiley & Sons Ltd on behalf of European Weed Research Society.
- Authors: Roberts, Jason , Dhileepan, Kunjithapatham , Florentine, Singarayer
- Date: 2024
- Type: Text , Journal article , Review
- Relation: Weed Research Vol. 64, no. 1 (2024), p. 8-18
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- Description: Ziziphus mauritiana is an economically detrimental and environmentally destructive plant in non-native areas where it has escaped cultivation. It forms dense, impenetrable thickets that restrict the movement of livestock across the landscape and has the capacity to alter various ecological functions at the site of invasion, all of which contribute towards land degradation and the reduction of economic profitability. Although there are several management strategies implemented to control Z. mauritiana, it is clear that no single-method approach will effectively control the species in the long-term. Whilst chemical and mechanical methods appear to show promising results, they tend to be restricted to areas that are easily accessible and, even so, can be challenging and laborious to treat evenly across dense thicket areas. Several prospective biological control agents have been identified for Z. mauritiana, although further investigations are required to ascertain the host specificity, and to explore and identify their climatic and environmental suitability of host specific agents for release in non-native regions. Ecological burning alone is not effective in controlling Z. mauritiana and will likely increase its emergence. As such, it could be adopted as part of an integrated management approach to assist other methods for long-term control, but again the development of such an approach requires further investigation. To contribute towards the control of Z. mauritiana, this review explores its biology, distribution and management challenges whilst identifying areas of research that will assist in the long-term and confident control of the species, with an emphasis on its invasion in Australia. © 2024 The Authors. Weed Research published by John Wiley & Sons Ltd on behalf of European Weed Research Society.
Advancements and developments in the detection and control of invasive weeds : a global review of the current challenges and future opportunities
- Roberts, Jason, Florentine, Singarayer
- Authors: Roberts, Jason , Florentine, Singarayer
- Date: 2024
- Type: Text , Journal article , Review
- Relation: Weed Science Vol. 72, no. 3 (2024), p. 205-215
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- Description: Weed invasion has become increasingly recognized as a major threat to the practice of sustainable agriculture and the maintenance of natural ecosystems around the world. Without effective and ongoing management strategies, many weed species have the aggressive capacity to alter ecosystem functions and reduce the economic potential of the land into which they have been introduced. Although traditional weed management strategies can be useful in eliminating certain weeds, these approaches can be costly, economically damaging, and laborious and can result in variable long-term success. To further add to these challenges, several weed species have now developed resistance to a range of herbicide modes of action, which, to date, have been the major mechanism of weed control. As a result, it is anticipated that the use of emerging technology will help to provide a solution for the economical and environmentally sustainable management of various weeds. Of particular interest, emerging technology in the areas of weed detection and control (chemical, mechanical, electrical, laser, and thermal) has shown promising signs of improving long-term weed management strategies. These methods can also be assisted by, or integrated alongside, other technology, such as artificial intelligence or computer vision techniques for improved efficiency. To provide an overview of this topic, this review evaluates a range of emerging technology used for the detection and control of various weeds and explores the challenges and opportunities of their application within the field. © The Author(s), 2024. Published by Cambridge University Press on behalf of Weed Science Society of America.
- Authors: Roberts, Jason , Florentine, Singarayer
- Date: 2024
- Type: Text , Journal article , Review
- Relation: Weed Science Vol. 72, no. 3 (2024), p. 205-215
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- Description: Weed invasion has become increasingly recognized as a major threat to the practice of sustainable agriculture and the maintenance of natural ecosystems around the world. Without effective and ongoing management strategies, many weed species have the aggressive capacity to alter ecosystem functions and reduce the economic potential of the land into which they have been introduced. Although traditional weed management strategies can be useful in eliminating certain weeds, these approaches can be costly, economically damaging, and laborious and can result in variable long-term success. To further add to these challenges, several weed species have now developed resistance to a range of herbicide modes of action, which, to date, have been the major mechanism of weed control. As a result, it is anticipated that the use of emerging technology will help to provide a solution for the economical and environmentally sustainable management of various weeds. Of particular interest, emerging technology in the areas of weed detection and control (chemical, mechanical, electrical, laser, and thermal) has shown promising signs of improving long-term weed management strategies. These methods can also be assisted by, or integrated alongside, other technology, such as artificial intelligence or computer vision techniques for improved efficiency. To provide an overview of this topic, this review evaluates a range of emerging technology used for the detection and control of various weeds and explores the challenges and opportunities of their application within the field. © The Author(s), 2024. Published by Cambridge University Press on behalf of Weed Science Society of America.
- Hossain, Nazia, Murshed, Manzur, Awrangjeb, Mohammad, Florentine, Singarayer, Irvin, Marc, Teng, Shyh
- Authors: Hossain, Nazia , Murshed, Manzur , Awrangjeb, Mohammad , Florentine, Singarayer , Irvin, Marc , Teng, Shyh
- Date: 2024
- Type: Text , Conference paper
- Relation: 2024 IEEE International Conference on Multimedia and Expo Workshops, ICMEW 2024, Niagra Falls, 15-19 July 2024, 2024 IEEE International Conference on Multimedia and Expo Workshops
- Full Text: false
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- Description: Over the recent years, airborne Light Detection and Ranging (LiDAR) data has been used to detect the egg incubators (a.k.a. mounds) of Malleefowl on large conservation areas. However, the mound detection accuracy of the existing automated methods is not high enough to be implemented in the field. To improve the detection accuracy, this paper focuses on the mound and its habitat-based feature extraction and classification, using the distinctive geometric behaviour of and surrounding the mound. We propose a novel feature extraction method of mounds, which leverages the slope of the ground with a planar terrain model (a.k.a. the ground plane) obtained by least squares plane fitting of the ground points. By observing the features based on the ground plane, we extract structural and habitat features, and group the mound-like ground points using clustering. Finally, we apply several binary classifier models to detect areas with mounds, among them Medium Gaussian SVM performs the best (around 95 % accuracy). Our training and testing datasets contain LiDAR point cloud data captured from the Tarawi Nature Reserve by the New South Wales Government in Australia. © 2024 IEEE.
Effect of selected environmental factors on the seed germination of the invasive species Polygala myrtifolia (Polygalaceae) in Australia
- Roberts, Natalie, Moloney, Katrina, Monie, Kristin, Florentine, Singarayer
- Authors: Roberts, Natalie , Moloney, Katrina , Monie, Kristin , Florentine, Singarayer
- Date: 2023
- Type: Text , Journal article
- Relation: Australian Journal of Botany Vol. 71, no. 6 (2023), p. 286-295
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- Description: Context. Polygala myrtifolia L. has become a significant environmental weed in Australia, where it has invaded coastal ecosystems in temperate regions and there is a high risk of extensive further spread. Knowledge of seed-germination behaviour is essential to understand the potential future impact of this species. Aims. We investigated the effects of selected environmental factors and dormancy on P. myrtifolia seed germination and emergence to improve management strategies. Methods. Seeds were exposed to light, temperature, pH, salinity, osmotic potential and burial depth treatments to assess germination responses, dormancy and viability. Key results. Non-dormant seeds readily germinated to high percentages (93.0–95.0%) under specific day–night temperatures of 25°C–15°C regardless of light conditions and across all soil pH (75.0–100.0%). Salinities were tolerated up to 100 mM NaCl (70.0% germination) before sharply declining. Germination reduced from 98.3% to 40.0% at osmotic potentials of
- Authors: Roberts, Natalie , Moloney, Katrina , Monie, Kristin , Florentine, Singarayer
- Date: 2023
- Type: Text , Journal article
- Relation: Australian Journal of Botany Vol. 71, no. 6 (2023), p. 286-295
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- Description: Context. Polygala myrtifolia L. has become a significant environmental weed in Australia, where it has invaded coastal ecosystems in temperate regions and there is a high risk of extensive further spread. Knowledge of seed-germination behaviour is essential to understand the potential future impact of this species. Aims. We investigated the effects of selected environmental factors and dormancy on P. myrtifolia seed germination and emergence to improve management strategies. Methods. Seeds were exposed to light, temperature, pH, salinity, osmotic potential and burial depth treatments to assess germination responses, dormancy and viability. Key results. Non-dormant seeds readily germinated to high percentages (93.0–95.0%) under specific day–night temperatures of 25°C–15°C regardless of light conditions and across all soil pH (75.0–100.0%). Salinities were tolerated up to 100 mM NaCl (70.0% germination) before sharply declining. Germination reduced from 98.3% to 40.0% at osmotic potentials of
Exploring efficient techniques to decrease phosphorus levels in previously farmed land to promote the revival of indigenous grassland
- Shakir, Shakir, Florentine, Singarayer, Schultz, Nick
- Authors: Shakir, Shakir , Florentine, Singarayer , Schultz, Nick
- Date: 2023
- Type: Text , Journal article
- Relation: Passer Journal of Basic and Applied Sciences Vol. 5, no. 2 (2023), p. 371-376
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- Description: Restoration of native grasslands is challenging due to high soil phosphorus levels. Cultivation of plants with high phosphorus (P) absorption is an optimal solution to remove and decrease P from the soil. It has been demonstrated that native grassland taxa (species) of the genus Ptilotus have significant P-uptake. In a glasshouse study, Ptilotus macrocephalus and Ptilotus polystachyus were tested for their ability to reduce the amount of soil phosphorus that was readily available. Lupinus albus, a third species with a reputation for high phosphorus uptake, served as a comparison species, and a further treatment included Phoslock®, a soil additive that could bind soil phosphorus into insoluble forms. The findings revealed that phosphorus in the soil was absorbed at a high level via Ptilotus macrocephalus and Ptilotus polystachyus showed a maximum reduction of P (-2.58 and -2.55 ppm). It is argued that several years of planting and harvesting these plants will offer a workable method for lowering soil phosphorus levels. However, this only happened at high concentrations of 1500 g/m2 and when soil phosphorus concentrations were very high. Despite, the Phoslock®'s effectiveness in lowering soil-accessible phosphorus. At concentrations often observed in former agriculture paddocks, it proved less effective. The study's findings have improved our existing comprehension of reclaiming abandoned grassland. © 2023 Authors. All rights reserved.
- Authors: Shakir, Shakir , Florentine, Singarayer , Schultz, Nick
- Date: 2023
- Type: Text , Journal article
- Relation: Passer Journal of Basic and Applied Sciences Vol. 5, no. 2 (2023), p. 371-376
- Full Text:
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- Description: Restoration of native grasslands is challenging due to high soil phosphorus levels. Cultivation of plants with high phosphorus (P) absorption is an optimal solution to remove and decrease P from the soil. It has been demonstrated that native grassland taxa (species) of the genus Ptilotus have significant P-uptake. In a glasshouse study, Ptilotus macrocephalus and Ptilotus polystachyus were tested for their ability to reduce the amount of soil phosphorus that was readily available. Lupinus albus, a third species with a reputation for high phosphorus uptake, served as a comparison species, and a further treatment included Phoslock®, a soil additive that could bind soil phosphorus into insoluble forms. The findings revealed that phosphorus in the soil was absorbed at a high level via Ptilotus macrocephalus and Ptilotus polystachyus showed a maximum reduction of P (-2.58 and -2.55 ppm). It is argued that several years of planting and harvesting these plants will offer a workable method for lowering soil phosphorus levels. However, this only happened at high concentrations of 1500 g/m2 and when soil phosphorus concentrations were very high. Despite, the Phoslock®'s effectiveness in lowering soil-accessible phosphorus. At concentrations often observed in former agriculture paddocks, it proved less effective. The study's findings have improved our existing comprehension of reclaiming abandoned grassland. © 2023 Authors. All rights reserved.
Phytoremediation of atmospheric pollutants in the era of climate change
- Khan, Atika, Riaz, Anam, Mahmood, Athar, Bibi, Safura, Florentine, Singarayer, Javaid, Muhammad, Nargis, Javaria
- Authors: Khan, Atika , Riaz, Anam , Mahmood, Athar , Bibi, Safura , Florentine, Singarayer , Javaid, Muhammad , Nargis, Javaria
- Date: 2023
- Type: Text , Book chapter
- Relation: Climate-resilient agriculture, vol 1 : crop responses and agroecological perspectives Chapter 12 p. 257-272
- Full Text: false
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- Description: It is now widely recognized that natural vegetation and many economically important crop species are significantly harmed by a variety of compounds that are found in the atmosphere in the form of pollutants. These pollutants are the result of anthropomorphic actions, which lead to increasing concentrations of harmful chemicals in the atmosphere. These include oxides of sulfur and nitrogen, ozone (O 3), volatile organic compounds (VOCs), carbon monoxide, fluorides, and organic particulate matter (PM). With regard to the effect of these chemicals on crops and other vegetable species, the amount and type of damage depend on the concentration of gaseous pollutants in the atmosphere, the duration of the exposure time for the crops, and the nature of the growing season. Furthermore, the genotype of the plant governs the extent of damage caused by these atmospheric pollutants and can result in either acute or chronic damage. Polluting chemical contaminants have a variety of direct impacts on vegetation, which can include the plants' heat exchange parameters, together with their biological properties, antimicrobial activities, gene functions, and yielding characteristics. In addition, they frequently show modifications to the foliar structure and photosynthetic processes, which can cause an increase in the emission of reactive oxygen species, which are harmful to the plants' biological, physiological, and biochemical processes. These species can include hydroxyl radicals, singlet oxygen, and hydrogen peroxide, and, consequently, the health of crops, for example, will require remedial action, such as the neutralization of free radicals by the formation and coordinated action of enzymatic and nonenzymatic antioxidants. In order to contribute to such remediation processes, this chapter has focused on these air pollutants and their impact on vital physiological functions such as photosynthesis, respiration, carbon allocation, and the stomatal function of plants. © The Author(s). All rights reserved.
Potential contributions of the soil seed bank and seed rain for accelerating the restoration of riparian catchments in Australia
- Florentine, Singarayer, Milberg, Per, Westbrooke, Martin
- Authors: Florentine, Singarayer , Milberg, Per , Westbrooke, Martin
- Date: 2023
- Type: Text , Journal article
- Relation: Global Ecology and Conservation Vol. 47, no. (2023), p.
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- Description: The quality and quantity of soil seed bank composition can play a key role in secondary succession restoration efforts such as those involved in this study, which concerned the restoration of damaged native sites in riparian environments in Victoria, Australia. The objective of this study of the restoration work was to determine the role played by naturally existing soil seed bank in the success of natural restoration in these restored and unmanaged riparian areas. In this regard, we sampled the soil seed bank, seed rain, seedlings in the field and vegetation cover from three sub catchments defined by restoration attempts which had been conducted (i) < 3 years, (ii) 4–8 years, and (iii) > 9 years previous to sampling. In addition, (iv) in order to provide comparative data, adjacent sites (iv) chosen for future restoration and (v) with remnant vegetation, were also sampled. From samples, a total of 8858 seedlings were recorded from the seed bank and the vegetation survey showed 170 species, with exotic species being more numerous than native. The seed rain (a total of 1422 seeds) was dominated by exotic species at all sites. When comparing the vegetation distribution and the seed rain composition, it was clear that whilst the seed bank was more promising as a comparative recruitment source of native species, there were still too many sites dominated by exotic species to rely on this as a long-term restoration strategy. However, this study indicated that there were significant variations in restoration potential among the sites, suggesting that some careful prior site selection for investment of restoration efforts is an important issue. As a consequence, we have recommended that a detailed understanding of the soil seed bank and seed rain species composition prior to the restoration is essential, since a positive seed bank composition with a significant relative density of native species seeds, will provide an indication of native species’ resilience and their potential for recovery. We therefore believe that the findings of this study will provide valuable information to natural resource management agencies regarding the strategy for prioritisation of restoration sites, which will be more beneficial than randomly selecting sites for habitat restoration. In addition, with successful sector restoration, it is expected that the increasing usefulness of the seed bank will allow further restoration of adjacent areas with time. © 2023 The Authors
- Authors: Florentine, Singarayer , Milberg, Per , Westbrooke, Martin
- Date: 2023
- Type: Text , Journal article
- Relation: Global Ecology and Conservation Vol. 47, no. (2023), p.
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- Reviewed:
- Description: The quality and quantity of soil seed bank composition can play a key role in secondary succession restoration efforts such as those involved in this study, which concerned the restoration of damaged native sites in riparian environments in Victoria, Australia. The objective of this study of the restoration work was to determine the role played by naturally existing soil seed bank in the success of natural restoration in these restored and unmanaged riparian areas. In this regard, we sampled the soil seed bank, seed rain, seedlings in the field and vegetation cover from three sub catchments defined by restoration attempts which had been conducted (i) < 3 years, (ii) 4–8 years, and (iii) > 9 years previous to sampling. In addition, (iv) in order to provide comparative data, adjacent sites (iv) chosen for future restoration and (v) with remnant vegetation, were also sampled. From samples, a total of 8858 seedlings were recorded from the seed bank and the vegetation survey showed 170 species, with exotic species being more numerous than native. The seed rain (a total of 1422 seeds) was dominated by exotic species at all sites. When comparing the vegetation distribution and the seed rain composition, it was clear that whilst the seed bank was more promising as a comparative recruitment source of native species, there were still too many sites dominated by exotic species to rely on this as a long-term restoration strategy. However, this study indicated that there were significant variations in restoration potential among the sites, suggesting that some careful prior site selection for investment of restoration efforts is an important issue. As a consequence, we have recommended that a detailed understanding of the soil seed bank and seed rain species composition prior to the restoration is essential, since a positive seed bank composition with a significant relative density of native species seeds, will provide an indication of native species’ resilience and their potential for recovery. We therefore believe that the findings of this study will provide valuable information to natural resource management agencies regarding the strategy for prioritisation of restoration sites, which will be more beneficial than randomly selecting sites for habitat restoration. In addition, with successful sector restoration, it is expected that the increasing usefulness of the seed bank will allow further restoration of adjacent areas with time. © 2023 The Authors
- Waudby, Helen, Turak, Eren, Callister, Kate, Florentine, Singarayer, Westbrooke, Martin, Palmer, Grant, Dayman, Ray
- Authors: Waudby, Helen , Turak, Eren , Callister, Kate , Florentine, Singarayer , Westbrooke, Martin , Palmer, Grant , Dayman, Ray
- Date: 2023
- Type: Text , Journal article
- Relation: Australian Journal of Zoology Vol. 71, no. 1 (2023), p.
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- Description: Determining species’ distributions is challenging for cryptic species that are difficult to detect using standard techniques. The mallee worm-lizard (Aprasia inaurita Kluge, 1974) is a cryptic reptile in the family Pygopodidae, listed as Endangered in New South Wales. We modelled the species’ potential distribution (Maxent) to improve understanding of the species’ distribution and surveyed potential habitat in the Scotia Mallee region (an area with suitable habitat) from 2018 to 2022, with pitfall traps and artificial refuges (terracotta roof tiles). We completed 11 587 pitfall trap-nights and 3200 tile checks over eight monitoring sessions. Over this period, we detected six vertebrate species (all lizards) using roof tiles and 40 species with pitfall traps, but no mallee worm-lizards. Evaluation of existing records of the mallee worm-lizard from NSW suggested that the state constitutes the north-eastern edge of its continental range, with the species apparently present in low numbers across a wide swathe of south-western NSW. Most records were located within or near to spinifex or porcupine grass (Triodia spp.) communities, on private land. Species distribution modelling provided outputs that are useful for spatial prioritisation of conservation efforts for the species, with region-wide maps showing that much of the Scotia Mallee study area contains potentially suitable habitat for the mallee worm-lizard. However, habitat suitability scores for individual cells in this area were low, in some instances, because of high maximum summer temperatures and soil available water capacity. We anticipate that increasing temperatures associated with climate change may further reduce the suitability of habitat in this area in the future. © 2023 The Author(s)
The response of Nassella trichotoma (serrated tussock) seeds and seedlings to different levels of fire intensity
- Humphries, Talia, Florentine, Singarayer
- Authors: Humphries, Talia , Florentine, Singarayer
- Date: 2023
- Type: Text , Journal article
- Relation: Australian Journal of Botany Vol. 71, no. 4 (2023), p. 188-198
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- Description: Context Fire is an important disturbance regime in grassland communities, since it is responsible for stimulating the regeneration of many species and for maintaining levels of biodiversity. When invasive plants, such as Nassella trichotoma, establish and become widespread in a grassland community, these important fire events can be altered in intensity and frequency, which means that they are able to facilitate the establishment of the exotic species. Therefore, before fire can be recommended as a suitable control technique for invasive species, or alternatively to be integrated into grassland restoration programs, understanding the response of the seeds of exotic species to high temperatures, such as those experienced during a fire, should be well understood. Aims Our aim was to identify their response to a gradient of temperatures associated with different levels of fire intensity. We examined how increased duration of exposure affects their response, and whether seed age or seed moisture content affect the germination response of this species. Methods To gain a fuller understanding of the fire response of N. trichotoma’s seedbank, seeds were collected in 2016, 2017, 2018 and 2019 and then stored until the commencement of the experiments in 2020. Selected seeds were first subjected to an increasing temperature gradient (80°C, 100°C, 120°C, 140°C, and a control), and an increasing duration of exposure (of 1, 3, 6, and 9 min). In the second experiment, one population was selected to test these same temperatures and duration of exposure after the seeds were hydrated to 15%, 50%, or 95%. Last, seedlings were grown for 3 months under glasshouse conditions and then exposed to increasing temperatures (20°C, 60°C, 80°C, 100°C, and 120°C), and an increasing duration of exposure (3, 6, and 9 min). The seedlings were assessed 2 weeks after the heat exposure for signs of damage. Key results It was found that increased temperatures and duration of exposure had a subtle negative effect on germination parameters, including reduced total germination and increased time to 50% germination. The 140°C treatment was seen to be a significant threshold because it killed all the seeds at any duration of exposure. A significant difference among the ages of each seed lot was observed to be a factor on the tested germination metrics, with the oldest tested population (2016) demonstrating the highest germination percentage, uniformity, and rate. Seed germination percentage was significantly reduced for seeds hydrated to 95% compared with the control treatment, whereas no significant difference was observed for the seeds hydrated to 15% and 50%. For the heat treatment of the seedlings, damage to the leaves was observed in the 80°C, 100°C, and 120°C treatments, with some plants in the 120°C treatment experiencing extensive damage prior to resprouting. No seedlings were killed at the tested temperatures. Conclusions Results of this study indicated that fire may be a useful tool for reducing seedbank density by killing a high proportion of the seeds on the soil surface, or located within the top 1 cm of the soil profile, but not for seeds buried more deeply. Efficacy of fire on surface and shallow-buried seeds is improved with high seed moisture content however, these seeds buried below this depth are still protected by the soil from the lethal effects of temperature. Implications Fire implemented before seed set could be used to effectively kill a large proportion of N. trichotoma seeds. However, for more comprehensive control, it is recommended that chemical treatment is integrated with the fire treatment to improve the overall control efficiency.
- Authors: Humphries, Talia , Florentine, Singarayer
- Date: 2023
- Type: Text , Journal article
- Relation: Australian Journal of Botany Vol. 71, no. 4 (2023), p. 188-198
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- Description: Context Fire is an important disturbance regime in grassland communities, since it is responsible for stimulating the regeneration of many species and for maintaining levels of biodiversity. When invasive plants, such as Nassella trichotoma, establish and become widespread in a grassland community, these important fire events can be altered in intensity and frequency, which means that they are able to facilitate the establishment of the exotic species. Therefore, before fire can be recommended as a suitable control technique for invasive species, or alternatively to be integrated into grassland restoration programs, understanding the response of the seeds of exotic species to high temperatures, such as those experienced during a fire, should be well understood. Aims Our aim was to identify their response to a gradient of temperatures associated with different levels of fire intensity. We examined how increased duration of exposure affects their response, and whether seed age or seed moisture content affect the germination response of this species. Methods To gain a fuller understanding of the fire response of N. trichotoma’s seedbank, seeds were collected in 2016, 2017, 2018 and 2019 and then stored until the commencement of the experiments in 2020. Selected seeds were first subjected to an increasing temperature gradient (80°C, 100°C, 120°C, 140°C, and a control), and an increasing duration of exposure (of 1, 3, 6, and 9 min). In the second experiment, one population was selected to test these same temperatures and duration of exposure after the seeds were hydrated to 15%, 50%, or 95%. Last, seedlings were grown for 3 months under glasshouse conditions and then exposed to increasing temperatures (20°C, 60°C, 80°C, 100°C, and 120°C), and an increasing duration of exposure (3, 6, and 9 min). The seedlings were assessed 2 weeks after the heat exposure for signs of damage. Key results It was found that increased temperatures and duration of exposure had a subtle negative effect on germination parameters, including reduced total germination and increased time to 50% germination. The 140°C treatment was seen to be a significant threshold because it killed all the seeds at any duration of exposure. A significant difference among the ages of each seed lot was observed to be a factor on the tested germination metrics, with the oldest tested population (2016) demonstrating the highest germination percentage, uniformity, and rate. Seed germination percentage was significantly reduced for seeds hydrated to 95% compared with the control treatment, whereas no significant difference was observed for the seeds hydrated to 15% and 50%. For the heat treatment of the seedlings, damage to the leaves was observed in the 80°C, 100°C, and 120°C treatments, with some plants in the 120°C treatment experiencing extensive damage prior to resprouting. No seedlings were killed at the tested temperatures. Conclusions Results of this study indicated that fire may be a useful tool for reducing seedbank density by killing a high proportion of the seeds on the soil surface, or located within the top 1 cm of the soil profile, but not for seeds buried more deeply. Efficacy of fire on surface and shallow-buried seeds is improved with high seed moisture content however, these seeds buried below this depth are still protected by the soil from the lethal effects of temperature. Implications Fire implemented before seed set could be used to effectively kill a large proportion of N. trichotoma seeds. However, for more comprehensive control, it is recommended that chemical treatment is integrated with the fire treatment to improve the overall control efficiency.
- Roberts, Jason, Florentine, Singarayer
- Authors: Roberts, Jason , Florentine, Singarayer
- Date: 2022
- Type: Text , Journal article , Review
- Relation: Weed Research Vol. 62, no. 1 (2022), p. 75-84
- Full Text: false
- Reviewed:
- Description: Cabomba caroliniana [A. Gray] (Cabombaceae), also known as Carolina fanwort, is a native of South America which has now become a serious invasive threat to aquatic systems across the world. Its capacity to inundate a water column with active fragments and seeds makes the containment and management of C. caroliniana a challenging task and an ecological and economic necessity. Previous and current management efforts have been largely focussed on biological control, drawdown methods, herbicide application, manual removal, shading and the use of a concentrated urea solution. Although these methods have shown some success in reducing large infestations, they are generally considered to be unreliable when used alone since they are unable to contain or reduce the species in the long term with a single-use treatment protocol. It is feared that, without effective, improved and integrated management strategies, C. caroliniana will continue to invade aquatic ecosystems beyond its already wide current distribution, thus causing increased global economic and environmental damage. This review will therefore explore the biology and distribution of C. caroliniana and examine the current and previous attempts for its global management. It will also evaluate the most successful current treatments and clarify where research efforts are urgently needed for the improved long-term extirpation of this aquatic invader. © 2021 European Weed Research Society
A global review of the woody invasive alien species mimosa pigra (giant sensitive plant): Its biology and management implications
- Welgama, Amali, Florentine, Singarayer, Roberts, Jason
- Authors: Welgama, Amali , Florentine, Singarayer , Roberts, Jason
- Date: 2022
- Type: Text , Journal article
- Relation: Plants Vol. 11, no. 18 (2022), p. 2366
- Full Text:
- Reviewed:
- Description: Populations of invasive alien plants create disruptive plant communities that are extremely adaptable, imposing severe ecological impacts on agriculture, biodiversity and human activities. To minimise these impacts, prevention and effective weed management strategies are urgently required, including the identification of satellite populations before they invade new areas. This is a critical element that allows weed management practices to become both successful and cost-effective. Mimosa pigra L. (Giant sensitive plant) is an invasive weed that has spread across various environments around the world and is considered one of the world’s top 100 most invasive plant species. Being adaptable to a wide range of soil types, in addition to its woody protective prickles and low palatability, M. pigra has quickly spread and established itself in a range of habitats. Current control methods of this species include biological, chemical and physical methods, together with attempts of integrated application. Reports suggest that integrated management appears to be the most effective means of controlling M. pigra since the use of any single method has not yet proved suitable. In this regard, this review synthesises and explores the available global literature and current research gaps relating to the biology, distribution, impacts and management of M. pigra. The contribution of this work will help guide land managers to design appropriate and sustainable management programs to control M. pigra.
- Authors: Welgama, Amali , Florentine, Singarayer , Roberts, Jason
- Date: 2022
- Type: Text , Journal article
- Relation: Plants Vol. 11, no. 18 (2022), p. 2366
- Full Text:
- Reviewed:
- Description: Populations of invasive alien plants create disruptive plant communities that are extremely adaptable, imposing severe ecological impacts on agriculture, biodiversity and human activities. To minimise these impacts, prevention and effective weed management strategies are urgently required, including the identification of satellite populations before they invade new areas. This is a critical element that allows weed management practices to become both successful and cost-effective. Mimosa pigra L. (Giant sensitive plant) is an invasive weed that has spread across various environments around the world and is considered one of the world’s top 100 most invasive plant species. Being adaptable to a wide range of soil types, in addition to its woody protective prickles and low palatability, M. pigra has quickly spread and established itself in a range of habitats. Current control methods of this species include biological, chemical and physical methods, together with attempts of integrated application. Reports suggest that integrated management appears to be the most effective means of controlling M. pigra since the use of any single method has not yet proved suitable. In this regard, this review synthesises and explores the available global literature and current research gaps relating to the biology, distribution, impacts and management of M. pigra. The contribution of this work will help guide land managers to design appropriate and sustainable management programs to control M. pigra.
- Roberts, Jason, Florentine, Singarayer
- Authors: Roberts, Jason , Florentine, Singarayer
- Date: 2022
- Type: Text , Journal article , Review
- Relation: Weed Research Vol. 62, no. 2 (2022), p. 113-122
- Full Text: false
- Reviewed:
- Description: Amaranthus palmeri S. Watson (Palmer amaranth) is an invasive agricultural weed that has quickly risen from a state of relative obscurity to now being globally regarded as one of the most economically destructive and difficult to manage weed species. It is now found in more than 45 countries where it poses a serious threat to agricultural production systems. Amaranthus palmeri is known to aggressively compete against crop plants for resources such as light, space, nutrients and soil moisture, all of which can result in significant crop yield reduction or even lead to crop failure. It has also been reported that A. palmeri is highly prone to evolve herbicide resistance; this makes management exceedingly challenging. Whilst there have been several control approaches introduced to manage the spread and impact of A. palmeri, many of them require more specific and focused research for their successful local and widespread application. In this regard, this global review explores the species’ biology and global distribution patterns, together with previous and current management strategies. It also explores and identifies promising areas of research that still require further investigation to more confidently assist in the control and containment of this globally concerning weed. © 2021 European Weed Research Society.
Achievements, developments and future challenges in the field of bioherbicides for weed control : a global review
- Roberts, Jason, Florentine, Singarayer, Fernando, Wannakuwattewaduge, Tennakoon, Kushan
- Authors: Roberts, Jason , Florentine, Singarayer , Fernando, Wannakuwattewaduge , Tennakoon, Kushan
- Date: 2022
- Type: Text , Journal article
- Relation: Plants Vol. 11, no. 17 (2022), p.
- Full Text:
- Reviewed:
- Description: The intrusion of weeds into fertile areas has resulted in significant global economic and environmental impacts on agricultural production systems and native ecosystems, hence without ongoing and repeated management actions, the maintenance or restoration of these systems will become increasingly challenging. The establishment of herbicide resistance in many species and unwanted pollution caused by synthetic herbicides has ushered in the need for alternative, eco-friendly sustainable management strategies, such as the use of bioherbicides. Of the array of bioherbicides currently available, the most successful products appear to be sourced from fungi (mycoherbicides), with at least 16 products being developed for commercial use globally. Over the last few decades, bioherbicides sourced from bacteria and plant extracts (such as allelochemicals and essential oils), together with viruses, have also shown marked success in controlling various weeds. Despite this encouraging trend, ongoing research is still required for these compounds to be economically viable and successful in the long term. It is apparent that more focused research is required for (i) the improvement of the commercialisation processes, including the cost-effectiveness and scale of production of these materials; (ii) the discovery of new production sources, such as bacteria, fungi, plants or viruses and (iii) the understanding of the environmental influence on the efficacy of these compounds, such as atmospheric CO2, humidity, soil water stress, temperature and UV radiation. © 2022 by the authors.
- Authors: Roberts, Jason , Florentine, Singarayer , Fernando, Wannakuwattewaduge , Tennakoon, Kushan
- Date: 2022
- Type: Text , Journal article
- Relation: Plants Vol. 11, no. 17 (2022), p.
- Full Text:
- Reviewed:
- Description: The intrusion of weeds into fertile areas has resulted in significant global economic and environmental impacts on agricultural production systems and native ecosystems, hence without ongoing and repeated management actions, the maintenance or restoration of these systems will become increasingly challenging. The establishment of herbicide resistance in many species and unwanted pollution caused by synthetic herbicides has ushered in the need for alternative, eco-friendly sustainable management strategies, such as the use of bioherbicides. Of the array of bioherbicides currently available, the most successful products appear to be sourced from fungi (mycoherbicides), with at least 16 products being developed for commercial use globally. Over the last few decades, bioherbicides sourced from bacteria and plant extracts (such as allelochemicals and essential oils), together with viruses, have also shown marked success in controlling various weeds. Despite this encouraging trend, ongoing research is still required for these compounds to be economically viable and successful in the long term. It is apparent that more focused research is required for (i) the improvement of the commercialisation processes, including the cost-effectiveness and scale of production of these materials; (ii) the discovery of new production sources, such as bacteria, fungi, plants or viruses and (iii) the understanding of the environmental influence on the efficacy of these compounds, such as atmospheric CO2, humidity, soil water stress, temperature and UV radiation. © 2022 by the authors.
An integrated approach for the restoration of Australian temperate grasslands invaded by Nassella trichotoma
- Humphries, Talia, Turville, Christopher, Sinclair, Steven, Florentine, Singarayer
- Authors: Humphries, Talia , Turville, Christopher , Sinclair, Steven , Florentine, Singarayer
- Date: 2022
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 12, no. 1 (2022), p.
- Full Text:
- Reviewed:
- Description: Invasive plants are considered to be one of the biggest threats to environmental assets, and once established, they can be immensely difficult to control. Nassella trichotoma is an aggressive, perennial grass species, and is considered to be one of the most economically damaging weeds to grazing systems due to its unpalatability, as well as being one of the leading causes of biodiversity loss in grassland communities. This species produces high density seedbanks that rapidly respond to disturbance events. Despite control programs being developing in Australia since the 1930s, this species is still widespread throughout south-east Australia, indicating that a new management approach is critical to control this Weed of National Significance at the landscape scale. The present study explored the effect of 12 different combinations of herbicide, fire, a second application of herbicide, grazing exclusion, tillage and broadcasting seeds in order to reduce the above and below-ground density of N. trichotoma. A control treatment was also included. The results were assessed using a Hierarchy analysis, whereby treatments of increasing complexity were compared for their efficacy in reducing N. trichotoma cover and seedbank density, while simultaneously increasing the establishment of the broadcast species. Whilst all integrated treatments effectively reduced N. trichotoma’s seedbank, the treatments that included fire performed significantly better at simultaneously reducing N. trichotoma and increasing the establishment of broadcasted seeds. Overall, the integration of herbicide, fire and broadcasting native seeds was observed to provide the most economically feasible management strategy for the landscape scale restoration of a degraded temperate grassland dominated by N. trichotoma. © 2022, The Author(s).
- Authors: Humphries, Talia , Turville, Christopher , Sinclair, Steven , Florentine, Singarayer
- Date: 2022
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 12, no. 1 (2022), p.
- Full Text:
- Reviewed:
- Description: Invasive plants are considered to be one of the biggest threats to environmental assets, and once established, they can be immensely difficult to control. Nassella trichotoma is an aggressive, perennial grass species, and is considered to be one of the most economically damaging weeds to grazing systems due to its unpalatability, as well as being one of the leading causes of biodiversity loss in grassland communities. This species produces high density seedbanks that rapidly respond to disturbance events. Despite control programs being developing in Australia since the 1930s, this species is still widespread throughout south-east Australia, indicating that a new management approach is critical to control this Weed of National Significance at the landscape scale. The present study explored the effect of 12 different combinations of herbicide, fire, a second application of herbicide, grazing exclusion, tillage and broadcasting seeds in order to reduce the above and below-ground density of N. trichotoma. A control treatment was also included. The results were assessed using a Hierarchy analysis, whereby treatments of increasing complexity were compared for their efficacy in reducing N. trichotoma cover and seedbank density, while simultaneously increasing the establishment of the broadcast species. Whilst all integrated treatments effectively reduced N. trichotoma’s seedbank, the treatments that included fire performed significantly better at simultaneously reducing N. trichotoma and increasing the establishment of broadcasted seeds. Overall, the integration of herbicide, fire and broadcasting native seeds was observed to provide the most economically feasible management strategy for the landscape scale restoration of a degraded temperate grassland dominated by N. trichotoma. © 2022, The Author(s).
Assessing seed longevity of the Invasive Weed Navua Sedge (Cyperus aromaticus), by artificial ageing
- Chadha, Aakansha, Florentine, Singarayer, Dhileepan, Kunjithapatham, Turville, Christopher
- Authors: Chadha, Aakansha , Florentine, Singarayer , Dhileepan, Kunjithapatham , Turville, Christopher
- Date: 2022
- Type: Text , Journal article
- Relation: Plants Vol. 11, no. 24 (2022), p.
- Full Text:
- Reviewed:
- Description: Navua sedge (Cyperus aromaticus (Ridley) Mattf. & Kukenth) is a significant agricultural and environmental weed found in tropical island countries including north Queensland, Australia. It is a prolific seed producer and consequently forms a high-density seedbank, and therefore understanding the longevity and persistence of the seeds can provide critical information required for the management of this species. A laboratory-controlled artificial ageing experiment was conducted where the seeds were exposed to a temperature of 45 °C and 60% relative humidity for 125 days. Seeds were removed at various times (1, 2, 5, 9, 20, 30, 50, 75, 100 and 125 days) and their viability determined through standard germination tests. It took 20 days in the artificial ageing environment for the seeds to decline to 50% viability which indicates that Navua sedge has relatively short-lived persistent seeds. These findings will assist in developing a better understanding of the seedbank dynamics of this invasive species, allowing managers to tactically implement control strategies and prepare budgets for ongoing treatments, and have implications for the duration and success of management programs. © 2022 by the authors.
Assessing seed longevity of the Invasive Weed Navua Sedge (Cyperus aromaticus), by artificial ageing
- Authors: Chadha, Aakansha , Florentine, Singarayer , Dhileepan, Kunjithapatham , Turville, Christopher
- Date: 2022
- Type: Text , Journal article
- Relation: Plants Vol. 11, no. 24 (2022), p.
- Full Text:
- Reviewed:
- Description: Navua sedge (Cyperus aromaticus (Ridley) Mattf. & Kukenth) is a significant agricultural and environmental weed found in tropical island countries including north Queensland, Australia. It is a prolific seed producer and consequently forms a high-density seedbank, and therefore understanding the longevity and persistence of the seeds can provide critical information required for the management of this species. A laboratory-controlled artificial ageing experiment was conducted where the seeds were exposed to a temperature of 45 °C and 60% relative humidity for 125 days. Seeds were removed at various times (1, 2, 5, 9, 20, 30, 50, 75, 100 and 125 days) and their viability determined through standard germination tests. It took 20 days in the artificial ageing environment for the seeds to decline to 50% viability which indicates that Navua sedge has relatively short-lived persistent seeds. These findings will assist in developing a better understanding of the seedbank dynamics of this invasive species, allowing managers to tactically implement control strategies and prepare budgets for ongoing treatments, and have implications for the duration and success of management programs. © 2022 by the authors.
Assessing seedbank longevity and seed persistence of the invasive tussock grass nassella trichotoma using in-field burial and laboratory-controlled ageing
- Humphries, Talia, Florentine, Singarayer
- Authors: Humphries, Talia , Florentine, Singarayer
- Date: 2022
- Type: Text , Journal article
- Relation: Plants Vol. 11, no. 18 (2022), p.
- Full Text:
- Reviewed:
- Description: The ability to produce highly dense and persistent seedbanks is a major contributor to the successful widespread establishment of invasive plants. This study seeks to identify seed persistence and seedbank longevity for the invasive tussock grass Nassella trichotoma (Nees.) Hack. ex Arechav in order to recommend management strategies for preventing re-emergence from the seedbank. To determine the seedbank longevity and persistence, two experiments were conducted: (i) seeds were buried at four depths (0, 1, 2, and 4 cm) and collected and assessed for viability, seed decay, and in-field germination after 6, 9, 12, 15, and 18 months of field burial; and (ii) seeds were exposed to artificial ageing conditions (60% RH and 45 °C) for 1, 2, 5, 9, 20, 30, 50, 75, 100, and 120 days, and viability was determined through germination tests and tetrazolium tests. Less than 10% of the seeds collected after 12 months of in-field burial were viable. The artificial ageing treatment found germination declined to 50% after 5.8 days, further suggesting that N. trichotoma seeds are short lived. The results from both experiments indicate that N. trichotoma has a transient seedbank, with less than 10% of the seeds demonstrating short-term persistence. It is likely the persistent seeds beyond 12 months were exhibiting secondary dormancy as viable seeds did not germinate under optimal germination conditions. The “Best Practice Guidelines” recommend monitoring for seedbank recruitment for at least three years after treating N. trichotoma infestations. The results of this study support this recommendation as a small proportion of the seeds demonstrated short-term persistence. © 2022 by the authors.
- Authors: Humphries, Talia , Florentine, Singarayer
- Date: 2022
- Type: Text , Journal article
- Relation: Plants Vol. 11, no. 18 (2022), p.
- Full Text:
- Reviewed:
- Description: The ability to produce highly dense and persistent seedbanks is a major contributor to the successful widespread establishment of invasive plants. This study seeks to identify seed persistence and seedbank longevity for the invasive tussock grass Nassella trichotoma (Nees.) Hack. ex Arechav in order to recommend management strategies for preventing re-emergence from the seedbank. To determine the seedbank longevity and persistence, two experiments were conducted: (i) seeds were buried at four depths (0, 1, 2, and 4 cm) and collected and assessed for viability, seed decay, and in-field germination after 6, 9, 12, 15, and 18 months of field burial; and (ii) seeds were exposed to artificial ageing conditions (60% RH and 45 °C) for 1, 2, 5, 9, 20, 30, 50, 75, 100, and 120 days, and viability was determined through germination tests and tetrazolium tests. Less than 10% of the seeds collected after 12 months of in-field burial were viable. The artificial ageing treatment found germination declined to 50% after 5.8 days, further suggesting that N. trichotoma seeds are short lived. The results from both experiments indicate that N. trichotoma has a transient seedbank, with less than 10% of the seeds demonstrating short-term persistence. It is likely the persistent seeds beyond 12 months were exhibiting secondary dormancy as viable seeds did not germinate under optimal germination conditions. The “Best Practice Guidelines” recommend monitoring for seedbank recruitment for at least three years after treating N. trichotoma infestations. The results of this study support this recommendation as a small proportion of the seeds demonstrated short-term persistence. © 2022 by the authors.
Biology, distribution and management of the globally invasive weed Solanum elaeagnifolium Cav (silverleaf nightshade): A global review of current and future management challenges
- Roberts, Jason, Florentine, Singarayer
- Authors: Roberts, Jason , Florentine, Singarayer
- Date: 2022
- Type: Text , Journal article , Review
- Relation: Weed Research Vol. 62, no. 6 (2022), p. 393-403
- Full Text:
- Reviewed:
- Description: Solanum elaeagnifolium Cav (silverleaf nightshade) is a deep-rooted, multi-stemmed, perennial, herbaceous woody plant that has been observed to threaten agricultural and native biodiversity worldwide. It is widely agreed that without efficient integrated management, S. elaeagnifolium will continue to cause significant economic and environmental damage across multiple scales. It is estimated that the annual economic impact of S. elaeagnifolium in Australia exceeds AUD $62 million, with this figure likely to be much higher in other countries invaded by this plant. It can also tolerate a high level of abiotic stress and survive in a range of temperatures (below freezing point to 34°C) and areas with an average yearly rainfall between 250 and 600 mm. Its extensive deep taproot system is capable of regenerating asexually and with its many seed dispersal mechanisms; it can quickly spread and establish itself within a region. This makes containment and management of the species especially challenging. Previous management has largely been focused on biological control, competition, essential oils, grazing pressure, herbicide application and manual removal. Despite the large range of available management techniques, there has been little success in the long-term control of S. elaeagnifolium, and only a handful of methods such as essential oils and herbicide application have shown reasonable success for controlling this weed. Therefore, this review aims to synthesise the identified and potentially useful approaches to control S. elaeagnifolium that have been recorded in the literature which deal with its biology, distribution and management. It also explores previous and current management techniques to ascertain the research gaps and knowledge required to assist in the effective and economically sustainable management of this invasive weed. © 2022 The Authors. Weed Research published by John Wiley & Sons Ltd on behalf of European Weed Research Society.
- Authors: Roberts, Jason , Florentine, Singarayer
- Date: 2022
- Type: Text , Journal article , Review
- Relation: Weed Research Vol. 62, no. 6 (2022), p. 393-403
- Full Text:
- Reviewed:
- Description: Solanum elaeagnifolium Cav (silverleaf nightshade) is a deep-rooted, multi-stemmed, perennial, herbaceous woody plant that has been observed to threaten agricultural and native biodiversity worldwide. It is widely agreed that without efficient integrated management, S. elaeagnifolium will continue to cause significant economic and environmental damage across multiple scales. It is estimated that the annual economic impact of S. elaeagnifolium in Australia exceeds AUD $62 million, with this figure likely to be much higher in other countries invaded by this plant. It can also tolerate a high level of abiotic stress and survive in a range of temperatures (below freezing point to 34°C) and areas with an average yearly rainfall between 250 and 600 mm. Its extensive deep taproot system is capable of regenerating asexually and with its many seed dispersal mechanisms; it can quickly spread and establish itself within a region. This makes containment and management of the species especially challenging. Previous management has largely been focused on biological control, competition, essential oils, grazing pressure, herbicide application and manual removal. Despite the large range of available management techniques, there has been little success in the long-term control of S. elaeagnifolium, and only a handful of methods such as essential oils and herbicide application have shown reasonable success for controlling this weed. Therefore, this review aims to synthesise the identified and potentially useful approaches to control S. elaeagnifolium that have been recorded in the literature which deal with its biology, distribution and management. It also explores previous and current management techniques to ascertain the research gaps and knowledge required to assist in the effective and economically sustainable management of this invasive weed. © 2022 The Authors. Weed Research published by John Wiley & Sons Ltd on behalf of European Weed Research Society.
Challenges inherent in controlling prickly pear species; a global review of the properties of Opuntia stricta, Opuntia ficus-indica and Opuntia monacantha
- Humphries, Talia, Campbell, Shane, Florentine, Singarayer
- Authors: Humphries, Talia , Campbell, Shane , Florentine, Singarayer
- Date: 2022
- Type: Text , Journal article , Review
- Relation: Plants Vol. 11, no. 23 (2022), p.
- Full Text:
- Reviewed:
- Description: Opuntia species (prickly pear) were deliberately introduced to many countries around the world for fruit, cochineal dye production, living fencing or as ornamentals. They are now some of the world’s most significant weeds, particularly in regions with warm and or dry climates, as they pose threats to economic and environmental assets. In addition, they can cause considerable health issues for humans and animals. Opuntia spp. have prolific reproduction abilities, being able to reproduce both vegetatively and by seed. They have generalist pollination and dispersal requirements, which promotes their establishment and spread. Opuntia stricta, O. monacantha and O. ficus-indica are the most globally widespread of the Opuntia spp. In many countries, biological control agents, particularly the cactus moth (Cactoblastis cactorum) and various cochineal insects from the Dactylopius genus, have successfully reduced land-scape scale populations. On a smaller scale, controlling these weeds by either injecting or spraying the cladodes with herbicides can provide effective control. Care must be taken during herbicide treatments as any untreated areas will regenerate. While biological control is the most cost and time effective control method for landscape-scale infestations, further research into the combined efficacy of herbicides, fire, grubbing and pre-burial techniques would be beneficial for land managers to control small-scale and establishing populations. It would also be useful to have greater knowledge of the potential seedbank longevity and seed ecology of these species so that integrated management strategies can be developed to not only deal with initial populations but also the subsequent seedling regrowth. © 2022 by the authors.
- Authors: Humphries, Talia , Campbell, Shane , Florentine, Singarayer
- Date: 2022
- Type: Text , Journal article , Review
- Relation: Plants Vol. 11, no. 23 (2022), p.
- Full Text:
- Reviewed:
- Description: Opuntia species (prickly pear) were deliberately introduced to many countries around the world for fruit, cochineal dye production, living fencing or as ornamentals. They are now some of the world’s most significant weeds, particularly in regions with warm and or dry climates, as they pose threats to economic and environmental assets. In addition, they can cause considerable health issues for humans and animals. Opuntia spp. have prolific reproduction abilities, being able to reproduce both vegetatively and by seed. They have generalist pollination and dispersal requirements, which promotes their establishment and spread. Opuntia stricta, O. monacantha and O. ficus-indica are the most globally widespread of the Opuntia spp. In many countries, biological control agents, particularly the cactus moth (Cactoblastis cactorum) and various cochineal insects from the Dactylopius genus, have successfully reduced land-scape scale populations. On a smaller scale, controlling these weeds by either injecting or spraying the cladodes with herbicides can provide effective control. Care must be taken during herbicide treatments as any untreated areas will regenerate. While biological control is the most cost and time effective control method for landscape-scale infestations, further research into the combined efficacy of herbicides, fire, grubbing and pre-burial techniques would be beneficial for land managers to control small-scale and establishing populations. It would also be useful to have greater knowledge of the potential seedbank longevity and seed ecology of these species so that integrated management strategies can be developed to not only deal with initial populations but also the subsequent seedling regrowth. © 2022 by the authors.
Effect of Rhizome Fragment Length and Burial Depth on the emergence of a tropical invasive Weed Cyperus aromaticus (Navua Sedge)
- Chadha, Aakansha, Florentine, Singarayer, Dhileepan, Kunjithapatham, Turville, Christopher
- Authors: Chadha, Aakansha , Florentine, Singarayer , Dhileepan, Kunjithapatham , Turville, Christopher
- Date: 2022
- Type: Text , Journal article
- Relation: Plants Vol. 11, no. 23 (2022), p.
- Full Text:
- Reviewed:
- Description: Cyperus aromaticus (Navua sedge) is a problematic perennial weed in pastures and crops including sugarcane, banana, rice, and fruits and vegetables in tropical climates. It reproduces both via rhizomes and seeds. As a regenerative and storage organ, these rhizomes play an important part in the invasion, establishment, and persistence of this weed. To eliminate their regenerative ability, it is important to understand the regrowth potential with respect to rhizome fragment size and burial depth. This study evaluated the emergence of C. aromaticus from rhizomes in a controlled condition. Three different sizes of rhizome fragments were buried at seven depths of up to 20 cm in two soil types. The experimental measurements included (i) the time for tillers to emerge, (ii) the cumulative emergence of tillers, recorded weekly, and (iii) the number of underground emerging tillers. The cumulative shoot emergence and the number of underground tillers produced were found to be positively correlated with the initial length of the rhizome fragments and negatively correlated with the burial depth. The time for the emergence of the tillers was negatively correlated with the burial depth, and soil type had no significant effect on any of the parameters recorded. There was no emergence recorded from rhizomes buried at 15 cm depth and deeper, irrespective of their size. Our results indicate that the combination of the fragmentation of rhizomes into small pieces and a deep burial, below 15 cm, is an important aspect to control the regeneration of C. aromaticus from rhizomes, if tillage is carried out, and can therefore form a part of an integrated weed management strategy for this troublesome weed. © 2022 by the authors.
- Authors: Chadha, Aakansha , Florentine, Singarayer , Dhileepan, Kunjithapatham , Turville, Christopher
- Date: 2022
- Type: Text , Journal article
- Relation: Plants Vol. 11, no. 23 (2022), p.
- Full Text:
- Reviewed:
- Description: Cyperus aromaticus (Navua sedge) is a problematic perennial weed in pastures and crops including sugarcane, banana, rice, and fruits and vegetables in tropical climates. It reproduces both via rhizomes and seeds. As a regenerative and storage organ, these rhizomes play an important part in the invasion, establishment, and persistence of this weed. To eliminate their regenerative ability, it is important to understand the regrowth potential with respect to rhizome fragment size and burial depth. This study evaluated the emergence of C. aromaticus from rhizomes in a controlled condition. Three different sizes of rhizome fragments were buried at seven depths of up to 20 cm in two soil types. The experimental measurements included (i) the time for tillers to emerge, (ii) the cumulative emergence of tillers, recorded weekly, and (iii) the number of underground emerging tillers. The cumulative shoot emergence and the number of underground tillers produced were found to be positively correlated with the initial length of the rhizome fragments and negatively correlated with the burial depth. The time for the emergence of the tillers was negatively correlated with the burial depth, and soil type had no significant effect on any of the parameters recorded. There was no emergence recorded from rhizomes buried at 15 cm depth and deeper, irrespective of their size. Our results indicate that the combination of the fragmentation of rhizomes into small pieces and a deep burial, below 15 cm, is an important aspect to control the regeneration of C. aromaticus from rhizomes, if tillage is carried out, and can therefore form a part of an integrated weed management strategy for this troublesome weed. © 2022 by the authors.