Allelopathic potential of the newly emerging weed solanum mauritianum Scop. (solanaceae) in the wet tropics of north-east Queensland
- Authors: Florentine, Singarayer , Westbrooke, Martin
- Date: 2003
- Type: Text , Journal article
- Relation: Plant Protection Quarterly Vol. 18, no. 1 (2003), p. 23-25
- Full Text:
- Reviewed:
- Description: Solanum mauritianum
- Description: C1
- Description: 2003004172
Post-wildfire seedling colonisation patterns in a Eucalyptus delegatemsis (Myrtaceae) windthrow site at Snowy Rover National Park, Victoria
- Authors: Florentine, Singarayer , Westbrooke, Martin , Milberg, Per , Gibson, Matthew
- Date: 2008
- Type: Text , Journal article
- Relation: Australian Forestry Vol. 71, no. 1 (2008), p. 48-53
- Full Text:
- Reviewed:
- Description: During June 1998, a severe windstorm caused significant damage to a sub-alpine stand of Eucalyptus delegatensis (Myrtaceae) at the Snowy River National Park. In 2002, about 4.5 y after the windstorm, a study documented the effects on E. delegatensis and early understorey succession. In February 2003, wildfire burnt across the windthrow site and we examined the seedling recruitment patterns at windthrow–burn and burn-only sites. Our aim was to document the regeneration of the canopy-dominant E. delegatensis and to confirm that Acacia dealbata is a pioneer species that potentially interferes with or prevents regeneration of E. delegatensis. Permanent transects were established within the windthrow–burn and burn-only sites. The data suggest that the heavily disturbed (mounded) soil at the windthrow site had a strong positive influence on regeneration of both species. By providing favourable growing conditions, the disturbed soil appears to have assisted seedling survival and subsequent growth of the E. delegatensis, despite competition from dense, concurrently established A. dealbata.
- Description: C1
Efficiency of gall-inducing insects in the biological control of parthenium weed : Structural, metabolic and physiological changes
- Authors: Florentine, Singarayer , Raman, Anantanarayanan , Dhileepan, Kunjithapatham
- Date: 2001
- Type: Text , Journal article
- Relation: Antenna Vol. 25, no. (2001), p. 47-52
- Full Text: false
- Description: 2003004181
Observations on survival and early growth of natural regeneration in floodplain coolibah Eucalyptus victrix (Myrtaceae) in the Pilbara, Western Australia
- Authors: Fox, John , Florentine, Singarayer , Westbrooke, Martin , Hurst, Cameron
- Date: 2004
- Type: Text , Journal article
- Relation: Rangeland Journal Vol. 26, no. 2 (2004), p. 150-160
- Full Text: false
- Reviewed:
- Description: Observations are presented on the natural regeneration of Eucalyptus victrix L. Johnson and K. Hill (coolibah), the dominant tree species of grassy woodlands on the floodplain of the Fortescue River, north of Newman in the Pilbara district of Western Australia. The main objectives of this study were to examine: (i) survival of newly recruited E. victrix seedlings on flooded and burnt sites, and (ii) growth and survival of established plants in a gilgaied landscape. Populations of newly-recruited seedlings following flooding or fire were monitored opportunistically at 'Marillana' and 'Ethel Creek' stations, for up to two years from tagging. A population of saplings at 'Roy Hill' station was observed over eight years. Seedling densities of E. victrix in flooded sites were 0.32 and 1.03 plants/m2 in 1995 and 1997 respectively. Locally high densities reached from 1.2 to 17.7 plants/m2 on areas of 28 and 6 m2 respectively. At the burnt site at 'Ethel Creek', 1.30 plants/m2 were observed where 58 seedlings were recorded on an area of 445 m2 a year after a natural fire. Many of these persisted well into their second year, whereas seedlings recruited in the flooded sites generally lasted less than a year (250-376 days). In contrast, persistence of a cohort of 100 established saplings <2 m tall in a gilgaied landscape at 'Roy Hill' was high. During 8 years of observations, only one sapling was lost. Those found at the edges of gilgais had attained greater heights (3.91 ± 1.14 m) than saplings located inside (3.16 ± 0.95 m) or on top (3.12 ± 0.93 m) of the gilgais. This study demonstrates that the seedling stage in E. victrix is critical, in that once newly recruited individuals reach the sapling stage (0.6-1 m), mortality rates are much reduced. Unfortunately, it was not possible during the course of this study to locate a cohort of young seedlings that did survive and so any consideration of the conditions necessary for their survival is speculative.
- Description: C1
- Description: 2003000725
Dry lakes and drifting seed-heads : The ecology of fairy grass Lachnagrostis filiformis
- Authors: Gosney, Kathleen , Florentine, Singarayer , Hurst, Cameron
- Date: 2006
- Type: Text , Conference paper
- Relation: Paper presented at the15th Australian weeds conference, Adelaide : 24th September, 2006
- Full Text: false
- Reviewed:
- Description: Lachnagrostis filiformis (frost) Trin, commonly known as fairly grass, is a native grass that has recently become a major concern for rural communities.
- Description: E1
- Description: 2003001631
Exotic plant species invasion in south west New South Wales : Influence of a rare flooding event and grazing
- Authors: Florentine, Singarayer , Westbrooke, Martin
- Date: 2005
- Type: Text , Journal article
- Relation: Plant Protection Quarterly Vol. 20, no. 2 (2005), p. 42-45
- Full Text: false
- Reviewed:
- Description: The main objectives of this study were to investigate: (i) the distribution of exotic plant species in flooded and control (unflooded) areas in relation to a 1997 episodic flooding event and (ii) the influence of grazing in flooded and unflooded open and fenced plots on wed colonization.
- Description: 2003001069
Ecology of the endangered Southern Shepherd's Purse Ballantinia antipoda (Brassicaceae) and the associated moss mat community on Mount Alexander, Victoria
- Authors: Ambrose, Graeme , Florentine, Singarayer , Seidel, Jessica , Wilson, Michael
- Date: 2005
- Type: Text , Journal article
- Relation: Victorian Naturalist Vol. 122, no. (2005), p. 179-188
- Full Text:
- Reviewed:
- Description: Despite its rarity, conservation status and location within the regional park, there is only limited information on the ecology of B. antipoda. The significance of the micorhabitat provided by the associated moss mat community is unclear.
- Description: 2003001088
Restoration on abandoned tropical pasturelands - Do we know enough?
- Authors: Florentine, Singarayer , Westbrooke, Martin
- Date: 2004
- Type: Text , Journal article
- Relation: Journal for Nature Conservation Vol. 12, no. (2004), p. 85-94
- Full Text:
- Reviewed:
- Description: Tropical rainforests have been disappearing at an alarming rate. In addition to preserving remaining tropical rainforests, we need to convert degraded and abandoned pasturelands into secondary forests. To accelerate this, human intervention in the recovery process is essential. In this review paper we (i) encapsulate some of the problems, which might surface when converting abandoned land to secondary forest. (ii) Look at some of the restoration techniques used in restoration programs and propose additional techniques for consideration. Major barriers to natural regeneration on abandoned and degraded pasturelands are: weed infestation, lack of indigenous soil seed bank, lack of seed supply/movement, soil compaction, depletion of soil nutrients and unsuitable microclimate and microhabitat. Although several restoration techniques have been recommended, most restoration programs have been carried out using native seedling transplants to accelerate natural recruitment. Most restoration groups in the tropics are still in the initial stages of determining which species or species combination to chose to gain maximum benefit. On the other hand restoration ecologists are struggling to detect which techniques are most appropriate to restore degraded and abandoned pasturelands. Our review shows that there is immediate need for further research and development on restoration techniques by examining the ecological and economic effectiveness of: direct seeding, stem cuttings using native pioneer or climax species and simple manipulation such as displacing branches of pioneer species with mature seeds on abandoned and degraded pasturelands and artificial perching to accelerate natural regeneration. These techniques are essential to successfully heal the wound humans have inflicted on the most spectacular and species-rich ecosystems on earth.
- Description: C1
- Description: 2003000720
The arid land invasive weed Nicotiana glauca R. Graham (Solanaceae) : Population and soil seed bank dynamics, seed germination patterns and seedling response to flood and drought
- Authors: Florentine, Singarayer , Westbrooke, Martin , Gosney, Kathleen , Ambrose, Graeme , O’Keefe, M.
- Date: 2006
- Type: Text , Journal article
- Relation: Journal of Arid Environments Vol. 66, no. (2006), p. 218-230
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- Reviewed:
- Description: Disturbances in plant communities provide opportunities for weed germination, propagation, spread, and invasion. When the population density of a weed increases, fast-tracked and appropriate control management strategies are required. The objectives of this study were to: (i) examine the population and soil seed bank dynamics of Nicotiana glauca; (ii) compare the germination patterns of invasive N. glauca seeds collected from two states in Australia, and (iii) investigate the impact of a flood in September 1997 and subsequent drought on N. glauca seedlings. The density of N. glauca followed a steep positive increment during the sampling time (September 1999 to October 2004). The increment pattern was similar in flooded fenced and unfenced plots. Plant density increased over much of the observation period, but had declined to 80 and 432 stems ha−1, respectively, by October 2004. Stem density recorded in October 2004 along two transects radiating from the central point of the newly created lake demonstrated that a significant number of stems appeared to be dead. A soil seed bank study revealed that seed density varied significantly (p=0.0001) between flooded fenced (598.75±71) and flooded unfenced (327.5±66) plots. In contrast, no N. glauca seedlings were recruited from the soil collected from the control plots. Germination trials were undertaken on N. glauca seed collected from New South Wales. There was no significance difference detected between treatments light and temperature. Similarly, no interaction was found between light and temperature. A comparative study on seed germination patterns of N. glauca seeds collected from Ivanhoe, New South Wales, and the Flinders Ranges, South Australia, showed that temperature had a significant effect on N. glauca seed germination. The effect varied significantly with main variables (state, length and time) and also with different interactions, except state×light (p=0.3840). N. glauca seedlings exposed to flood were found to withstand partial flooding for at least 58 days. Under waterlogged conditions, the seedlings showed stem hypertrophy and produced adventitious roots. Only one seedling was found dead in the drought treatment. In conclusion, it is clear that N. glauca invaded the area after a rare flood event and began to function as a casual weed. Established seedlings in the field can withstand extreme ecological events such as flood and drought. Understanding the plants’ ecological characteristics through a study such as this at an early rather than late stage in the invasion will help us to take appropriate control measures for this species.
- Description: C1
- Description: 2003001616
Effects of gall induction by Epiblema strenuana on gas exchange, nutrients, and energetics in Parthenium hysterophorus
- Authors: Florentine, Singarayer , Raman, Anantanarayanan , Dhileepan, Kunjithapatham
- Date: 2005
- Type: Text , Journal article
- Relation: Biocontrol Vol. 50, no. 5 (Oct 2005), p. 787-801
- Full Text:
- Reviewed:
- Description: Gall induction by arthropods results in a range of morphological and physiological changes in their host plants. We examined changes in gas exchange, nutrients, and energetics related to the presence of stem galls on Parthenium hysterophorus L. (Asteraceae) induced by the moth, Epiblema strenuana Walker (Lepidoptera: Tortricidae). We compared the effects of galls on P. hysterophorus in the rosette (young), pre-flowering (mature), and flowering (old) stages. Gall induction reduced the leaf-water potential, especially in flowering stage plants. In young and mature stage plants, galling reduced photosynthetic rates considerably. Gall induction reduced the transpiration rate mostly in mature plants, and this also diminished stomatal conductance. Energy levels in most galls and in shoot tissue immediately below the galls were significantly higher than the energy levels in stem tissue immediately above the galls, indicating that the gall acts as a mobilizing sink for the moth. Galling had significant effects on concentrations of minerals such as boron, chloride, magnesium, and zinc. In galled plants, reduced leaf-water potential and reduced rates of photosynthesis, transpiration, and stomatal conductance may have altered mineral element levels. These observed effects demonstrate that E. strenuana has the potential to regulate P. hysterophorus.
- Description: C1
- Description: 2003001078
Recruitment and functionality traits as biondicators of ecological restoration success in the Lurg Hills district, Victoria, Australia
- Authors: Monie, Kristin , Florentine, Singarayer , Palmer, Grant
- Date: 2013
- Type: Text , Journal article
- Relation: Ecological Processes Vol. 2, no. 27 (2013), p. 1-11
- Full Text:
- Reviewed:
- Description: Introduction The Regent Honeyeater Project commenced ecological restoration in the Lurg district in 1994, with an aim to restore habitats for the critically endangered Regent Honeyeater Anthochaera phrygia and a range of other threatened and declining species. Within this context, our study aimed to explore whether plant reproduction can be an effective measure of ecological restoration success. Methods Evaluation involved comparing attributes at unrestored, restored and remnant sites to establish whether sites displayed evidence of a clear restoration trajectory. Five age classes (unrestored, 4–6 years old, 8–10 years old, 12–14 years old and remnant areas) and two landforms (upper hills and lower hills) were considered. The diversity of woody plant species—which have easily recognisable reproductive material and which all recruit seedlings—provides easily measured parameters that have the potential to allow the determination of early establishment success and long-term ecological development of restored ecosystems. Results Restoration plantings developed in a hybrid state towards a benchmark in the lower hills; seedling species composition differed significantly among age classes, increasing in similarity with time since restoration, with some divergence from the target pathway. Composition of functional groups with reproductive outputs was also significantly different among age classes; however, a restoration trajectory was only evident in the upper hills where sites converged towards the target goal. Conclusions Divergence or deviation from the restoration trajectory was not deemed to be a restoration failure, as the variety of functional groups with fruits and diversity of seedlings recruiting indicated a potential increase in resilience in the future due to greater variability across the landscape. Plant recruitment was effective in detecting development trends towards a restoration target in this study and therefore may be a useful measure that contributes to determining ecological restoration success
Auditing revegetated catchments in southern Australia : decomposition rates and collembolan species assemblages
- Authors: Greenslade, Penelope , Bell, Lesa , Florentine, Singarayer
- Date: 2011
- Type: Text , Journal article
- Relation: Soil organisms Vol. 83, no. 3 (2011), p. 433-450
- Relation: http://purl.org/au-research/grants/arc/LP0990642
- Full Text: false
- Reviewed:
- Description: Major government funds have been allocated to revegetation of degraded catchments in Australia in order to enhance biodiversity, protect stock and improve water quality. However, the success or otherwise of the different restoration practices used has not been assessed. To redress this deficiency we audited these practices by measuring biotic and abiotic variables in two field surveys, one at a landscape scale and the second at a local scale. The landscape survey comprised 21 sites in western Victoria, a third of the sites were revegetated and were between 8 and 12 years old, a third carried remnant native vegetation and a third were degraded and not revegetated. In the local survey the results of the landscape survey were tested by sampling sites within a small area using the same methods but including pine plantations as an untreated site. Here we report on density and species composition of soil and surface active fauna. native and exotic Collembola and decomposition rates as measured with bait laminae. Fifty seven species of Collembola were found on the landscape survey and 47 on the local survey. Densities ranged from 17,000 to 45,000 m-2 in soil. In both the surveys we found decomposition was directly related to soil moisture and in the landscape survey exotic Collembola (Hypogastrura and Ceratophysella spp) to abundance of exotic grass species. MDS analysis of soil Collembola in the landscape survey placed remnant sites separate from the revegetated sites and untreated sites. which tended to cluster together. A suite of nine native Collembola species were found exclusively on remnant sites in the landscape survey. In the local survey, the revegetated sites. here with a ground cover of native not exotic grasses, were found to have nine characterising species, four of which were the same indicators as in the landscape survey. The pine plantations were dominated by acidophil exotic Collembola species. MDS analysis of pitfall data in local survey placed all sites in the same space, except for one remnant because of domination by the same exotic species as in the landscape survey. In contrast. MDS of the soil-core data separated all three treatments with the revegetated sites occupying the space between the remnants and the pines as in the landscape survey. When exotic species were removed. there was spatial separation of each treatment. We conclude that. in some circumstances, soil fauna of revegetated sites can develop characteristics of remnant sites in terms of native Collembola even after only 8 to 12 years. The bait lamina method must be used with caution as it is strongly influenced by soil moisture.
- Description: Major government funds have been allocated to revegetation of degraded catchments in Australia in order to enhance biodiversity, protect stock and improve water quality. However, the success or otherwise of the different restoration practices used has not been assessed. To redress this deficiency we audited these practices by measuring biotic and abiotic variables in two field surveys, one at a landscape scale and the second at a local scale. The landscape survey comprised 21 sites in western Victoria, a third of the sites were revegetated and were between 8 and 12 years old, a third carried remnant native vegetation and a third were degraded and not revegetated. In the local survey the results of the landscape survey were tested by sampling sites within a small area using the same methods but including pine plantations as an untreated site. Here we report on density and species composition of soil and surface active fauna. native and exotic Collembola and decomposition rates as measured with bait laminae. Fifty seven species of Collembola were found on the landscape survey and 47 on the local survey. Densities ranged from 17,000 to 45,000 m
Plant recruitment and survival as indicators of ecological success in abandoned pasture land in Nurcoung
- Authors: Florentine, Singarayer , Gardner, Jessica , Graz, Patrick , Moloney, Sean
- Date: 2013
- Type: Text , Journal article
- Relation: Ecological Processes Vol. 2, no. 1-3 (2013), p.
- Full Text:
- Reviewed:
- Description: One of the major impediments to developing better restoration strategies is the inadequate documentation of past restoration efforts. In 2008, Greening Australia commenced ecological restoration on the Nurcoung property in Victoria to enhance local biodiversity, and in this paper we report on the habitat restoration outcomes in the three Ecological Vegetation Classes (EVC) found on this property.
The germinable soil seedbank of Eucalyptus victrix grassy woodlands at Roy Hill Station, Pilbara District, Western Australia
- Authors: Graham, R.A. , Florentine, Singarayer , Fox, John , Luong, T. M.
- Date: 2004
- Type: Text , Journal article
- Relation: Rangeland Journal Vol. 26, no. 1 (2004), p. 17-33
- Full Text: false
- Reviewed:
- Description: The paper reports soil seedbank species composition, of Eucalyptus victrix grassy woodlands, of the upper Fortescue River in the Pilbara District, Western Australia. In this study, our objectives were to investigate germinable soil seedbanks and species composition in response to three simulated seasons, using emergence. Variation in seed density from three depths was tested. Four field sites were sampled. Thirty samples were collected in late spring, after seed rain and prior to summer rainfall. From each sample spot, three soil depths (surface, 1-5, and 6-10 cm) were segregated from beneath surface areas of 100 cm(2). Samples were later incubated in a glasshouse to simulate three different seasonal conditions (autumn, winter and spring). Germinating seedlings were recorded on emergence and grown until identified. Forty-one species germinated, comprising 11 grasses (7 annuals and 4 perennials), 25 annual herbs and 5 perennial herbs. Distribution patterns of germinable seed in both the important annual grass Eragrostis japonica and the perennial Eragrostis setifolia (a preferred cattle fodder species), suggest that seedbank accumulation differs among species and between sites. In part, this may be associated with the absence of grazing. Species with most total germinable seed were E. japonica (Poaceae; 603/m(2)), and the annual herbs Calotis multicaulis (Asteraceae; 346/m(2)), and Mimulus gracilis (Scrophulariaceae; 168/m(2)). Perennial grass seed was sparse. Spring simulation gave most germination (1059), followed by autumn (892) and winter (376) sets. Greatest species diversity was produced from the spring simulation (33 species), followed by autumn (26), and winter (22). Of the total germination, 92% came from 17 species that were represented in all three simulations. Of the 1227 grass seedlings counted, most were recruited from the surface soil (735), followed by the 5 (310) and 10 (182) cm depths. Marginally more grass seedlings germinated from the spring simulation (558) than the autumn set (523). Only 11.9% of grass germinants came from the winter simulation. All grass species recruited from the soil seedbanks had a C-4 photosynthetic pathway. Except for Cenchrus ciliaris all grass species are native to Australia. Of the four sites sampled, one fenced to exclude cattle five years earlier had significantly more germination than the three unfenced sites. Seedbank sampling produced several new records for plants in the areas sampled.
- Description: C1
- Description: 2003000711
Gall-inducing insects and biological control of Parthenium hysterophorus L. (Asteraceae)
- Authors: Florentine, Singarayer , Raman, Anantanarayanan , Dhileepan, Kunjithapatham
- Date: 2001
- Type: Text , Journal article
- Relation: Plant Protection Quarterly Vol. 16, no. 2 (2001), p. 63-68
- Full Text:
- Reviewed:
- Description: 2003004178
Metabolite mobilization in the stem galls of Parthenium hysterophorus induced by Epiblema strenuana inferred from the signatures of isotopic carbon and nitrogen and concentrations of total non-structural carbohydrates
- Authors: Florentine, Singarayer , Raman, Anantanarayanan , Dhileepan, Kunjithapatham , Madhaven, S.
- Date: 2006
- Type: Text , Journal article
- Relation: Entomologia Experimentalis et Applicata Vol. 119, no. (2006), p. 101-107
- Full Text:
- Reviewed:
- Description: Parthenium hysterophorus L. (Asteraceae) is a weed of national significance in Australia. Among the several arthropod agents introduced into Australia to control populations of P. hysterophorus biologically, Epiblema strenuana Walker (Lepidoptera: Tortricidae) is the most widespread and abundant agent. By intercepting the normal transport mechanisms of P. hysterophorus, the larvae of E. strenuana drain nutrients, other metabolic products, and energy, and place the host plant under intense metabolic stress. In this study, determinations of total non-structural carbohydrates (TNC) levels and carbon and nitrogen isotope ratios of fixed products in different parts of the plant tissue, including the gall, have been made to establish the function of gall as a sink for the nutrients Values of
- Description: C1
- Description: 2003001571
Rainfall-driven Episodic Flood Events : Are they a major factor in moulding New South Wales arid land vegetation patterns?
- Authors: Florentine, Singarayer , Westbrooke, Martin
- Date: 2005
- Type: Text , Journal article
- Relation: Australian Geographer Vol. 36, no. 2 (2005), p. 171-181
- Full Text:
- Reviewed:
- Description: Episodic high rainfall has been proposed as an important factor in perennial species recruitment but flooding based on rainfall at a distance from the site has received little attention. Although such flood events in arid Australia are rare, studies of the ephemeral Olary Creek indicate that occasional floods can also have a high impact on the vegetation and landscape. During February 1997, a high-rainfall event caused flooding in the Olary Creek. One branch of the creek created a terminal lake within mallee vegetation on Nagaela Station in far-western New South Wales. The flood path of Olary Creek and this terminal lake allow study of the importance of rainfall-driven flood events in shaping vegetation in arid environments. This paper reports (i) the response of arid land plant species to high-rainfall-driven episodic flood events and (ii) how grazing pressure from native and introduced herbivores can impact on native species response. A systematic study was conducted to understand the botanical composition in flooded and control areas based on 25 m2 fenced and unfenced plots subjected to flooding and nonflooding. For 6 years following flooding, species richness in the flooded area was twice that of unflooded areas. In particular, 27 native species from 13 families were recorded both in the enclosed and open plots located in the flooded area. Over the study period nine species: Brachyscome ciliaris, Helichrysum leucopsidium, Vittadinia cuneata, Casuarina pauper, Maireana sedifolia, Salsola kali, Sclerolaena obliquicuspis, Eremophila sturtii and Eucalyptus foecunda germinated only in the flooded enclosed plots. Further, 11 exotic species from five families were recorded in the flooded (both enclosed and open) plots over the study period. Knowledge gained from this study will contribute to management strategies for arid land vegetation.
- Description: C1
- Description: 2003001067
A unique weed problem — the control of fairy grass Lachnagrostis filiformis seedheads on Lake Learmonth in western Victoria
- Authors: Warnock, Andrew , Florentine, Singarayer , Graz, Patrick , Westbrooke, Martin
- Date: 2008
- Type: Text , Conference paper
- Relation: Paper presented at 16th Australian Weeds Conference: Weed management 2008 hot topics in the tropics, Cairns, Queensland : May 18th-22nd, 2008 p. 165-167
- Full Text:
- Description: The native fairy grass (Lachnagrostis filiformis (G. Forst.) Trin.) has colonised extensive areas of dry lake beds in western Victoria during the current drought. Large numbers of the plants’ detached mature panicles (seed heads) lodge against housing, fences, railway lines and other obstacles. This can be a fire hazard, degrades township aesthetics and creates a general nuisance to communities of lakeside towns. Current control measures are costly and only provide short-term solutions. A three-year study commencing in 2006 was designed to assess current and innovative control measures and develop a potential long-term management solution to the problem. Treatments applied to the bed of Lake Learmonth during the first year of the study included late-season glyphosate herbicide at two concentrations, late-season slashing, and seed broadcasting of two native species to reduce L. filiformis inflorescence biomass through competition. Slashing reduced L. filiformis inflorescence biomass and herbicide treatments successfully killed L. filiformis plants, while having no effect on germination of seed collected from sprayed plants. Although these treatments successfully limited the impact of L. filiformis on lakeside towns during the first year, the longer term efficiency is doubted. Treatment effects will be monitored over a further two years.
- Description: 2003006269
Hydraulic heterogeneity in a highly weathered basaltic regolith : Impact on lateral-flow and solute transport
- Authors: Rasiah, Velu , Armour, John , Florentine, Singarayer
- Date: 2012
- Type: Text , Journal article
- Relation: Journal of Environmental Hydrology Vol. 20, no. 13 (2012), p.
- Full Text: false
- Reviewed:
- Description: Reliable on-ground information on groundwater (GW) hydraulic heterogeneity is required to determine flow direction and quantities, but its experimental characterization is difficult because of the complexities associated with the interaction involving the temporal changes in space modified by regolith stratigraphy. The impact of the aforementioned variables, particularly stratigraphy in a 51 m thick highly weathered basaltic regolith in the northeast humid tropics of Queensland, Australia, on flow gradients and directions was investigated in this study. Regolith cores at 1 m increments indicated that there were 3 different major strata. The temporal changes in water table, hydraulic- and pressure- heads, and solute concentrations in space indicated the top 51 m aquifer was contiguous, dynamic and hydraulically differentiated into three segments which approximately corresponded with the regolith strata. The lateralflow and solute transport from each aquifer segment was controlled by depth to water table, the number of regolith layers the segment covered, and the solute concentration.
- Description: 2003010399
The need for speed: Timely prevention of the dispersal of noxious weeds in relief fodder using efficient sampling procedures
- Authors: Weller, Sandra , Florentine, Singarayer , Sillitoe, Jim , Grech, Charles , McLaren, David , Chauhan, Bhagirath
- Date: 2015
- Type: Text , Journal article
- Relation: Crop Protection Vol. 70, no. (2015), p. 21-27
- Full Text:
- Reviewed:
- Description: Invasive and noxious weeds are well known as a pervasive problem, imposing significant economic burdens on all areas of agriculture. Whilst there are multiple possible pathways of weed dispersal in this industry, of particular interest to this discussion is the unintended dispersal of weed seeds within fodder. During periods of drought or following natural disasters such as wild fire or flood, there arises the urgent need for 'relief' fodder to ensure survival and recovery of livestock. In emergency situations, relief fodder may be sourced from widely dispersed geographic regions, and some of these regions may be invaded by an extensive variety of weeds that are both exotic and detrimental to the intended destination for the fodder. Pasture hay is a common source of relief fodder and it typically consists of a mixture of grassy and broadleaf species that may include noxious weeds. When required urgently, pasture hay for relief fodder can be cut, baled, and transported over long distances in a short period of time, with little opportunity for prebaling inspection. It appears that, at the present time, there has been little effort towards rapid testing of bales, post-baling, for the presence of noxious weeds, as a measure to prevent dispersal of seeds. Published studies have relied on the analysis of relatively small numbers of bales, tested to destruction, in order to reveal seed species for identification and enumeration. The development of faster, more reliable, and non-destructive sampling methods is essential to increase the fodder industry's capacity to prevent the dispersal of noxious weeds to previously unaffected locales.