Isolated remnant or recent introduction? Estimating the provenance of Yellingbo Leadbeater's possums by genetic analysis and bottleneck simulation
- Authors: Hansen, Birgita , Taylor, Andrea
- Date: 2008
- Type: Text , Journal article
- Relation: Molecular Ecology Vol. 17, no. 18 (2008), p. 4039-4052
- Full Text: false
- Reviewed:
- Description: Effective conservation management requires that genetically divergent populations potentially harbouring important local adaptations be identified and maintained as separate management units. In the case of the endangered Australian Leadbeater's possum (Gymnobelideus leadbeateri), an arboreal marsupial endemic to Victoria, uncertainty over the evolutionary origin of a potentially important extant wild population recently discovered in atypical habitat (lowland swamp) at Yellingbo is hampering such efforts. The population is rumoured to be a recent introduction. Microsatellite allele frequencies at Yellingbo differed substantially from those in sampled populations in montane ash forest (FST between 0.23 and 0.36), and Bayesian clustering analyses of genotypes strongly separated them (K = 2). We conducted a suite of bottlenecking tests which all indicated that Yellingbo had undergone a recent reduction in size. The extent to which the distinctiveness of Yellingbo animals might be expected solely through bottlenecking associated with a recent introduction, was tested by simulating population-history scenarios seeded with genotypes from candidate wild and captive sources. No bottleneck scenario reproduced anything approaching the genetic distinction of the Yellingbo population, with all structure analyses placing Yellingbo in a separate cluster to simulated populations (K = 2, minimum FST = 0.13). These results suggest that Yellingbo does not share recent ancestry with other extant populations and instead may be a remnant of an otherwise extinct gene pool. Importantly, this may include genes involved in adaptation to a lowland swamp environment, substantially adding to the conservation importance of this population, and suggesting that separate management may be prudent until evidence suggests otherwise. © 2008 The Authors.
Assessing capture and tagging methods for brolgas, Antigone rubicunda (Gruidae)
- Authors: Veltheim, Inka , Chavez-Ramirez, Felipe , Hill, Richard , Cook, Simon
- Date: 2015
- Type: Text , Journal article
- Relation: Wildlife Research Vol. 42, no. 5 (2015), p. 373-381
- Full Text: false
- Reviewed:
- Description: Context Studies assessing welfare issues and efficiency of animal capture methods are important, as capture can pose a significant welfare risk and methods can be time consuming to develop. It is imperative to choose methods that minimise injuries, maximise capture rates and minimise time spent on capture. Aims To test methods of crane capture and tagging (transmitter, colour and metal band fitting), and to compare and develop safe and time efficient methods for capturing brolgas (Antigone rubicunda). Methods We tested three types of noose traps, cannon nets, clap-nets, spotlighting at night roosts and active pursuit of pre-fledged chicks. We also tested two band sizes and two transmitter attachment methods. We compared the success and capture efficiency of these methods and considered welfare issues by comparing the number of injuries and mortalities resulting from these methods. Key results We successfully captured brolgas with noose traps and a cannon net, and by using active pursuit of pre-fledged chicks. Noose traps became more efficient when deployed with call playback and taxidermy decoys. Australian noose traps and active pursuit of pre-fledged chicks were the safest methods with fewest injuries. Conclusions For maximum capture success with minimum injuries to target and non-target species, we recommend noose traps with call playback and taxidermy decoys for capturing adult and juvenile brolgas at feeding areas, and active pursuit for pre-fledged chicks at breeding sites. Noose lines should have elastic at both pegged ends, to avoid injuries. To minimise injuries from tagging, we recommend leg-band-fitted transmitters in preference to harness-fitted transmitters, Australian size 35 bands and colour bands with an internal diameter of 22mm. Implications The use of Australian noose traps with call playback and taxidermy decoys is a safe and time efficient method for capturing brolgas, and is also likely to work for other crane species. Our recommendations can help reduce capture-related mortalities and injuries to brolgas (and potentially other cranes), which is crucial, given the brolga is a threatened species. © 2015 CSIRO.
Methane and CO2 emissions from China's hydroelectric reservoirs: a new quantitative synthesis
- Authors: Li, Siyue , Zhang, Quanfa , Bush, Richard , Sullivan, Leigh
- Date: 2015
- Type: Text , Journal article
- Relation: Environmental Science and Pollution Research Vol. 22, no. 7 (2015), p. 5325-5339
- Full Text: false
- Reviewed:
- Description: Controversy surrounds the green credentials of hydroelectricity because of the potentially large emission of greenhouse gases (GHG) from associated reservoirs. However, limited and patchy data particularly for China is constraining the current global assessment of GHG releases from hydroelectric reservoirs. This study provides the first evaluation of the CO
Chromosome numbers in Australian charophytes (Characeae, Charophyceae)
- Authors: Casanova, Michelle
- Date: 2015
- Type: Text , Journal article
- Relation: Phycologia Vol. 54, no. 2 (2015), p. 149-160
- Full Text: false
- Reviewed:
- Description: Over the course of a 25 year ecological and taxonomic study, the chromosomes of Australian charophytes (family Characeae) were examined and enumerated. The usual number for members of Chara was n = 14 (for dioecious species) or n = 28 (for monoecious species); although Chara braunii has always been recorded as having n = 14 despite being monoecious. Species in sections Agardhia and Grovesia often had higher ploidy levels [n = 3 x 14 (42), n = 4 x 14 (56)]. The usual number for Australian members of Nitella was n = 9 (for dioecous species) and n = 18, 24 or 27 for monoecious species. Nitella stuartii was an exception, having n = 15 in the specimens studied here. The usual number for monoecious members of Lamprothamnium was n = 28; although, monoecious Lamprothamnium inflatum consistently had n = 14 (populations from Western Australia, Kangaroo Island and South Australia). Chromosome numbers were different for each species of Tolypella examined (n = 11 to 36). There was a high degree of polyploidy within Characeae, and there was evidence that even the lowest numbers of chromosomes represented polyploids (3n for Nitella and 2n for Chara). Polyploidy and consequent doubling or tripling of enzymatic capacity (via potential multiple isozymes) is likely to have a role in the morphological variability and biochemical flexibility of charophytes. Information about the number and appearance of chromosomes (karyotypes) can be used in systematic studies to determine relatedness of taxa and to understand some of the evolutionary processes operating at the population or species level. © 2015 International Phycological Society.
Vitamins in brewing : Effects of post-fermentation treatments and exposure and maturation on the thiamine and riboflavin vitamer content of beer
- Authors: Hucker, Barry , Vriesekoop, Frank , Vriesekoop-Beswick, Arielle , Wakeling, Lara , Vriesekoop-Besick, Hamish , Hucker, Amy
- Date: 2016
- Type: Text , Journal article
- Relation: Journal of the Institute of Brewing Vol. 122, no. 2 (2016), p. 278-288
- Full Text: false
- Reviewed:
- Description: Post-fermentation processes and maturation are important steps in beer production as they help to shape the organoleptic properties and stabilize the final product. Brewers can use a variety of processing aids (e.g. isinglass, PVPP, etc.) and processes (e.g. pasteurization, bottle conditioning, etc.) to achieve a desired final product with a desirable shelf life; however, these processes can have detrimental effects on the vitamin content of the beer. This research found that heat treatments have a marked influence on the decrease in the thiamine diphosphate vitamer, while PVPP and silica treatments have a greater influence on the decrease in riboflavin vitamers. Refrigeration, filtration or centrifugation have no, or only very limited, influence on thiamine or riboflavin vitamers, while application of isinglass, bentonite, tannic acid and SO2 causes a decrease in both thiamine and riboflavin vitamers. Storage of beer at refrigerated temperatures appears to provide protection against significant degradation of both thiamine and riboflavin vitamers; however, storage of filtered beer at elevated temperatures shows a decrease in thiamine diphosphate and riboflavin. Storage of bottle-conditioned beer at elevated temperatures shows a marked decrease in yeast viability, accompanied by a decrease in thiamine diphosphate and free riboflavin, and a marked increase in free thiamine. These findings provide an insight into the reason why there is a significant variation in the vitamer content of beers, even within a single beer style. © 2016 The Institute of Brewing & Distilling.
The NF-κB1 transcription factor prevents the intrathymic development of CD8 T cells with memory properties
- Authors: Gugasyan, Raffi , Horat, Elisha , Kinkel, Sarah , Ross, Fiona , Grigoriadis, George , Gray, Daniel , O'Keeffe, Meredith , Berzins, Stuart , Belz, Gabrielle , Grumont, Raelene , Banerjee, Ashish , Strasser, Andreas , Godfrey, Dale , Tsichlis, Phillip , Gerondakis, Steve
- Date: 2012
- Type: Text , Journal article
- Relation: EMBO Journal Vol. 31, no. 3 (2012), p. 692-706
- Full Text: false
- Reviewed:
- Description: The role of specific members of the NF-κB family of transcription factors in CD8 T-cell selection and development is largely unknown. Here, we show that mice lacking NF-κB1 develop a unique population of conventional CD8 single-positive (SP) thymocytes with memory T cell-like properties that populate peripheral immune organs. Development of this memory-like population is not due to PLZF + thymocytes and instead coincides with changes in CD8 T-cell selection. These include a reduction in the efficiency of negative selection and a dependence on MHC class Ia or Ib expressed by haematopoietic cells. These findings indicate that NF-κB1 regulates multiple events in the thymus that collectively inhibit the excess development of CD8 + thymocytes with memory cell characteristics. © 2012 European Molecular Biology Organization | All Rights Reserved.
Improved identification of sulfidic soil materials by a modified incubation method
- Authors: Sullivan, Leigh , Ward, Nicholas , Bush, Richard , Burton, Edward
- Date: 2009
- Type: Text , Journal article
- Relation: Geoderma Vol. 149, no. 1-2 (2009), p. 33-38
- Full Text: false
- Reviewed:
- Description: This study examines the acidification behaviour and rate of sulfidic-sulfur oxidation in the incubation method that is currently used in soil taxonomies to identify sulfidic materials, for some clayey textured soil materials. 'Sulfidic' in these taxonomies identifies that a soil material is capable of becoming extremely acidic (i.e. pH < 4) as a result of oxidation of sulfide minerals contained in that soil material. As well as examining incubation slabs of acid sulfate soil materials with the standard 10 mm thickness, the utility of thinner (i.e. 2 mm thick) incubation slabs of these soil materials for identification of sulfidic soil materials was also examined. The clayey soil materials in the 2 mm thick slabs exhibited more rapid sulfidic-sulfur oxidation and acidification and resulted in fewer false-negative sulfidic soil material identifications than did the use of 10 mm thick slabs. However, the rates of sulfidic-sulfur oxidation and sulfide-derived acidification within the slabs (whether 2 mm or 10 mm thick) were not always rapid enough during incubation for the full expression of acidification to be evident within the maximum incubation duration of 8 weeks required by soil classification taxonomies. The results indicate the incubation method for determination of the sulfidic nature of soil materials for soil classification purposes could be improved to reduce the risk of false-negative identification by: i. allowing the use of 2 mm thick slabs, and ii. changing the maximum duration of incubation from 8 weeks to until a stable pH is reached after at least 8 weeks of incubation. © 2008.
Collembola in Southland beech litter and soil
- Authors: Phillips, Craig , Brown, Samuel , Greenslade, Penelope , Reay, Stephen , Allen, Robert , Easdale, Tomás , Dickie, Ian
- Date: 2015
- Type: Text , Journal article
- Relation: New Zealand Entomologist Vol. 38, no. 2 (2015), p. 79-87
- Full Text: false
- Reviewed:
- Description: Collembola were sampled from litter and soil in two regrowth Lophozonia menziesii (silver beech) forests situated 25 km apart in Southland, New Zealand, as part of a larger study investigating the ecological effects of selective timber harvesting. Over 2000 specimens were collected, representing three orders, 10 families, ≥ 20 genera and ≥ 23 species. Seventeen taxa were morphologically identified at least to genus. Sequencing within the barcode region of the mitochondrial cytochrome c oxidase 1 gene provided diagnostic sequences for many of the taxa, which will assist future identifications. Species belonging to the genera Quatacanthella Salmon and Spinotheca Stach, which are rarely collected in New Zealand, were present in the samples, as was the introduced species Hypogastrura purpurescens (Lubbock). The genus Vitronura Yosii is recorded in New Zealand for the first time. © 2015 AgResearch Ltd.
The influence of thiamine and riboflavin on various spoilage microorganisms commonly found in beer
- Authors: Hucker, Barry , Christophersen, Melinda , Vriesekoop, Frank
- Date: 2017
- Type: Text , Journal article
- Relation: Journal of the Institute of Brewing Vol. 123, no. 1 (2017), p. 24-30
- Full Text: false
- Reviewed:
- Description: Beer is generally considered a stable product owing to its intrinsic ‘unfavourable’ conditions (hops, alcohol, low oxygen, etc.) that inhibit the growth of pathogenic microorganisms. However spoilage microorganism such as Lactobacillus brevis, Pediococcus damnosus, Acetobacter aceti, Zymomonas mobilis and various wild yeasts (e.g. Brettanomcyes spp.) can have significant detrimental effects on the organoleptic properties of the final product. The presence of essential vitamins, such as thiamine and riboflavin, can help to enhance the growth of these microorganisms, accelerating the rate of spoilage. The presence of thiamine had a noticeable effect on the lactic acid productivity of L. brevis and P. damnosus, acetaldehyde productivity of Z. mobilis and acetic acid production of Brettanomyces spp., while riboflavin enhanced 2,3-pentanedione production by P. damnosus and Brettanomyces spp. Copyright © 2017 The Institute of Brewing & Distilling. Copyright © 2017 The Institute of Brewing & Distilling
Carbon bio-sequestration within the phytoliths of economic bamboo species
- Authors: Parr, Jeffrey , Sullivan, Leigh , Chen, Bihua , Ye, Gongfu , Zheng, Weipeng
- Date: 2010
- Type: Text , Journal article
- Relation: Global Change Biology Vol. 16, no. 10 (2010), p. 2661-2667
- Full Text: false
- Reviewed:
- Description: The rates of carbon bio-sequestration within silica phytoliths of the leaf litter of 10 economically important bamboo species indicates that (a) there is considerable variation in the content of carbon occluded within the phytoliths (PhytOC) of the leaves between different bamboo species, (b) this variation does not appear to be directly related to the quantity of silica in the plant but rather the efficiency of carbon encapsulation by the silica. The PhytOC content of the species under the experimental conditions ranged from 1.6% to 4% of the leaf silica weight. The potential phytolith carbon bio-sequestration rates in the leaf-litter component for the bamboos ranged up to 0.7 tonnes of carbon dioxide (CO
Phylogenetic congruence of ribosomal operon and plastid gene sequences for the Characeae with an emphasis on Tolypella (Characeae, Charophyceae)
- Authors: Pérez, William , Casanova, Michelle , Hall, John , McCourt, Richard , Karol, Kenneth
- Date: 2017
- Type: Text , Journal article
- Relation: Phycologia Vol. 56, no. 2 (2017), p. 230-237
- Full Text: false
- Reviewed:
- Description: To clarify species diversity of Tolypella (Characeae, Charophyceae) and the relationship between Tolypella and other genera in Characeae, sequence data from the nuclear ribosomal operon were assembled for 18 individuals of Tolypella. These represented nine named species and two potentially new species from Australia, as well as 13 other taxa of Characeae. Phylogenetic analyses were performed on ribosomal gene sequences (18S, 5.8S and 28S) for Characeae and on ribosomal gene and internal transcribed spacer (ITS) sequences (ribosomal genes þ ITS1 þ ITS2) for Tolypella. Analyses were also performed on the ribosomal gene and ITS sequences combined with plastid gene sequences (atpB, psbC and rbcL). Ribosomal gene sequences alone were conservative and their phylogenetic analyses resulted in topologies similar to a previously published plastid gene-based study but with less support and resolution. In contrast, ITS sequences showed greater variability and their addition resulted in greater resolution among some species relationships of Tolypella. The addition of plastid sequences also resulted in greater support and increased resolution in some lineages but not all.
Population genetic analysis reveals a long-term decline of a threatened endemic Australian marsupial
- Authors: Hansen, Birgita , Harley, Daniel , Lindenmayer, David , Taylor, Andrea
- Date: 2009
- Type: Text , Journal article
- Relation: Molecular Ecology Vol. 18, no. 16 (2009), p. 3346-3362
- Full Text: false
- Reviewed:
- Description: Since European colonization, Leadbeater's possum (Gymnobelideus leadbeateri) has declined across its range to the point where it is now only patchily distributed within the montane ash forests of the Central Highlands of Victoria. The loss of large hollow-bearing trees coupled with inadequate recruitment of mature ash forest has been predicted to result in a reduction in population size of up to 90% by 2020. Furthermore, bioclimatic analyses have suggested additional reductions in the species' distribution under a variety of climate change scenarios. Using a panel of 15 highly resolving microsatellite markers and mitochondrial control region sequence data, we infer past and present gene flow. Populations in the northern part of the core range were highly admixed, and showed no signs of either current or historical barriers to gene flow. A marginal, isolated and inbred population at Yellingbo was highly genetically differentiated, both in terms of current and historic genetic structure. Sequence data confirmed the conclusions from earlier genetic simulation studies that the Yellingbo population has been isolated from the rest of the species range since before European-induced changes to the montane landscape, and formed part of a larger genetic unit that is now otherwise extinct. Historic loss of maternal lineages in the Central Highlands of Victoria was detected despite signals of immigration, indicating population declines that most probably coincided with changes in climate at the end of the Pleistocene. Given ongoing habitat loss and the recent (February 2009) wildfire in the Central Highlands, we forecast (potentially extensive) demographic declines, in line with predicted range reductions under climate change scenarios. © 2009 Blackwell Publishing Ltd.
Enhanced methane hydrate storage using sodium dodecyl sulfate and coal
- Authors: Hao, Shu-Qing , Kim, Sungho , Qin, Yong , Fu, Xue-Hai
- Date: 2014
- Type: Text , Journal article
- Relation: Environmental Chemistry Letters Vol. 12, no. 2 (2014), p. 341-346
- Full Text: false
- Reviewed:
- Description: A potential solution to reduce global warming is to store greenhouse gases. Greenhouse gas storage has been recently improved using several materials and techniques. However, the actual storage capacity is slow, limited, and costly. Here, we tested the use of an accelerating agent, sodium dodecyl sulfate, and coal to produce methane hydrate for methane storage. Experiments of storing methane gas in coal samples have been carried out under high pressures, 4 or 6 MPa, and low temperature of 273.15 K. Results reveal that sodium dodecyl sulfate improved the rate up to 58.26 cm3/min and the capacity up to 179.97 volume at standard temperature and pressure per unit volume of coal. This finding shows that sodium dodecyl sulfate is efficient to accelerate the formation of methane hydrate. We also found that storage capacity increased with pressure. We conclude that our method allows a gas storage capacity higher than any other medium materials reported previously. © 2013 Springer-Verlag Berlin Heidelberg.
Pore water sampling in acid sulfate soils : A new peeper method
- Authors: Johnston, Scott , Burton, Edward , Keene, Annabelle , Bush, Richard , Sullivan, Leigh , Isaacson, Lloyd
- Date: 2009
- Type: Text , Journal article
- Relation: Journal of Environmental Quality Vol. 38, no. 6 (2009), p. 2474-2477
- Full Text: false
- Reviewed:
- Description: This study describes the design, deployment, and application of a modified equilibration dialysis device (peeper) optimized for sampling pore waters in acid sulfate soils (ASS). The modified design overcomes the limitations of traditional-style peepers, when sampling firm ASS materials over relatively large depth intervals. The new peeper device uses removable, individual cells of 25 mL volume housed in a 1.5 m long rigid, high-density polyethylene rod. The rigid housing structure allows the device to be inserted directly into relatively firm soils without requiring a supporting frame. The use of removable cells eliminates the need for a large glove-box after peeper retrieval, thus simplifying physical handling. Removable cells are easily maintained in an inert atmosphere during sample processing and the 25-mL sample volume is sufficient for undertaking multiple analyses. A field evaluation of equilibration times indicates that 32 to 38 d of deployment was necessary. Overall, the modified method is simple and effective and well suited to acquisition and processing of redox-sensitive pore water profiles > 1 m deep in acid sulfate soil or any other firm wetland soils. Copyright © 2009 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.
The effect of short-term creatine loading on active range of movement
- Authors: Sculthorpe, Nicholas , Grace, Fergal , Jones, Peter , Fletcher, Iain
- Date: 2010
- Type: Text , Journal article
- Relation: Applied Physiology, Nutrition, and Metabolism Vol. 35, no. 4 (2010), p. 507-511
- Full Text: false
- Reviewed:
- Description: During high-intensity exercise, intracellular creatine phosphate (PCr) is rapidly broken down to maintain adenosine triphosphate turnover. This has lead to the widespread use of creatine monohydrate as a nutritional ergogenic aid. However, the increase in intracellular PCr and the concomitant increase in intracellular water have not been investigated with regard to their effect on active range of movement (ROM). Forty male subjects (age, 24+/-3.2 years) underwent restricted randomization into 2 equal groups, either an intervention group (CS) or a control group (C). The CS group ingested 25 g.day(-1) of creatine monohydrate for 5 days, followed by 5 g.day(-1) for a further 3 days. Before (24 h before starting supplementation (PRE) and after (on the 8th day of supplementation (POST)) this loading phase, both groups underwent goniometry measurement of the shoulder, elbow, hip, and ankle. Data indicated significant reductions in active ROM in 3 movements: shoulder extension (57+/-11.3 degrees PRE vs. 48+/-11.2 degrees POST, p<0.01), shoulder abduction (183.4+/-6.8 degrees PRE vs. 180.3+/-5.1 degrees POST, p<0.05), and ankle dorsiflexion (14.2+/-4.7 degrees PRE vs. 12.1+/-6.4 degrees POST, p<0.01). There was also a significant increase in body mass for the CS group (83.6+/-6.2 kg vs. 85.2+/-6.3 kg, p<0.05). The results suggest that short-term supplementation with creatine monohydrate reduces the active ROM of shoulder extension and abduction and of ankle dorsiflexion. Although the mechanism for this is not fully understood, it may be related to the asymmetrical distribution of muscle mass around those joints.
Runs of Homozygosity : Association with Coronary Artery Disease and Gene Expression in Monocytes and Macrophages
- Authors: Christofidou, Paraskevi , Nelson, Christopher , Nikpay, Majid , Qu, Liming , Li, Mingyao , Loley, Christina , Debiec, Radoslaw , Braund, Peter , Denniff, Matthew , Charchar, Fadi , Arjo, Ares Rocanin , Trégouët, David-Alexandre , Goodall, Alison , Cambien, Francois , Ouwehand, Willem , Roberts, Robert , Schunkert, Heribert , Hengstenberg, Christian , Reilly, Muredach , Erdmann, Jeanette , McPherson, Ruth , König, Inke , Thompson, John , Samani, Nilesh , Tomaszewski, Maciej
- Date: 2015
- Type: Text , Journal article
- Relation: American Journal of Human Genetics Vol. 97, no. 2 (2015), p. 228-237
- Full Text: false
- Reviewed:
- Description: Runs of homozygosity (ROHs) are recognized signature of recessive inheritance. Contributions of ROHs to the genetic architecture of coronary artery disease and regulation of gene expression in cells relevant to atherosclerosis are not known. Our combined analysis of 24,320 individuals from 11 populations of white European ethnicity showed an association between coronary artery disease and both the count and the size of ROHs. Individuals with coronary artery disease had approximately 0.63 (95% CI: 0.4-0.8) excess of ROHs when compared to coronary-artery-disease-free control subjects (p = 1.49 x 10
The golf ball method for rapid assessment of grassland structure
- Authors: Schultz, Nick , Keatley, Marie , Antos, Mark , Wong, Nathan , Moxham, Claire , Farmilo, Brad , Morgan, John
- Date: 2017
- Type: Text , Journal article
- Relation: Ecological Management and Restoration Vol. 18, no. 2 (2017), p. 134-140
- Full Text: false
- Reviewed:
- Description: A key task for native grassland managers is to assess when biomass reduction is necessary to maintain plant and animal diversity. This requires managers to monitor grassland structure. Parks Victoria and La Trobe University developed a method for rapid assessment of grassland structure using golf balls. Baker-Gabb et al. (Ecological Management & Restoration, 17, 2016, p235) provide an example of where the method has been used to manage grassland structure to favour an endangered bird, the Plains-wanderer (Pedionomus torquatus). In this study, we provide further critical analysis of the method using three data sets collected across different parts of Victoria that relate golf ball scores to various habitat attributes. We demonstrate how the golf ball score provides a good surrogate for key aspects of grassland structure. We show that the method does not provide a reliable surrogate for above-ground biomass or vegetation cover, although we discuss how biomass and cover are not particularly good indicators of grassland structure. We argue that elements of grassland structure may be better correlated with desired conservation outcomes (e.g. plant species diversity or the presence of a particular species) than biomass or cover alone. We discuss examples of how the golf ball method has been used, and how it can be improved. The method will be particularly useful where a link can be demonstrated between golf ball scores and desired conservation outcomes, such as in the case of the Plains-wanderer. © 2017 Ecological Society of Australia and John Wiley & Sons Australia, Ltd
A field trial to test effects of watering, seed addition and disturbance on perennial species recruitment in Belah woodland
- Authors: Callister, Katrina , Westbrooke, Martin
- Date: 2017
- Type: Text , Journal article
- Relation: Ecological Management and Restoration Vol. 18, no. 3 (2017), p. 246-249
- Full Text: false
- Reviewed:
- Description: Failure of perennial species to regenerate is a significant threat to semi-arid woodlands across south-eastern Australia. High grazing pressure eliminates the recruitment of many perennial species in semi-arid woodlands, but little is known about requirements for regeneration under low grazing pressure. We tested the effects of addition of water (irrigation to match the largest rainfall events of the last century), seed, soil disturbance and fire within a grazing exclosure in Belah (Casuarina pauper) woodland in the Murray-Sunset National Park, Victoria. Recruitment was observed in 13 perennial species and was dominated by chenopods. Addition of water, seed and soil disturbance increased abundance of juvenile perennial species above the low-level background recruitment that occurred in the prevailing drought conditions. This supports the view that continuous recruitment occurs for many semi-arid perennials. Low seed availability and an inability to maintain soil moisture conditions matching that of regeneration events are likely factors in the lack of recruitment for tree species and limited response of shrubs in this experiment. © 2017 Ecological Society of Australia and John Wiley & Sons Australia, Ltd
Effects of varying organic matter content on the development of green roof vegetation: A six year experiment
- Authors: Bates, Adam , Sadler, Jon , Greswell, Richard , Mackay, Rae
- Date: 2015
- Type: Text , Journal article
- Relation: Ecological Engineering Vol. 82, no. September (2015), p. 301-310
- Full Text: false
- Reviewed:
- Description: Green roofs can potentially be used to tackle a variety of environmental problems, and can be used as development mitigation for the loss of ground-based habitats. Brown (biodiversity) roofs are a type of green roof designed to imitate brownfield habitat, but the best way of engineering these habitats requires more research. We tested the effects of altering organic matter content on the development of vegetation assemblages of experimental brown (biodiversity) roof mesocosms. Three mulch treatments were tested: (1) sandy loam, where 10 mm of sandy loam mulch (about 3% organic matter by dry weight) was added to 100 mm of recycled aggregate; (2) compost, where the mulch also contained some garden compost (about 6% organic matter by dry weight); and (3) no mulch, where no mulch was added. Mesocosms were seeded with a wildflower mix that included some Sedum acre, and vegetation development was investigated over a six-year period. Species richness, assemblage character, number of plants able to seed, and above-ground plant biomass were measured. Drought disturbance was an important control on plant assemblages in all mulch treatments, but there were significant treatment response interactions. The more productive compost treatment was associated with larger plant coverage and diversity before the occurrence of a sequence of drought disturbances, but was more strongly negatively affected by the disturbances than the two less productive treatments. We suggest that this was due to the over-production of plant biomass in the more productive treatment, which made the plants more vulnerable to the effects of drought disturbance, leading to a kind of 'boom-bust' assemblage dynamic. The 'ideal' amount of added organic matter for these green roof systems was very low, but other types of green roof that have a larger water holding capacity, and/or more drought resistant plant floras, will likely require more organic matter or fertiliser. Nonetheless, nutrient-supported productivity in green roof systems should be kept low in order to avoid boom-bust plant assemblage dynamics. Research into the best way of engineering green roof habitats should take place over a long enough multi-year time period to include the effects of temporally infrequent disturbances. © 2015 Elsevier B.V.
The 3D distribution of phyllosilicate clay minerals in western Victoria
- Authors: Robinson, Nathan , Kitching, Matt
- Date: 2016
- Type: Text , Journal article
- Relation: Geoderma Vol. 284, no. (2016), p. 152-177
- Full Text: false
- Reviewed:
- Description: The mineralogy of the clay fraction of soils is a major determinant of the behavior of soil. Conventionally these clay minerals have been determined using techniques such as X-ray Diffraction (XRD), but new complementary methods such as infrared spectroscopy can be used to rapidly and economically predict these minerals. This paper presents a methodology to predict these clay minerals at high-resolution that adhere to GlobalSoilMap (GSM) standards. Mid-infrared (MIR) spectroscopic models were formulated for clay minerals kaolinite, illite and smectite using partial least squares regression (PLSR) and legacy quantitative XRD determinations. Very strong models were achieved for kaolinite, illite and smectite and the root mean square error of cross validation (RMSECV) were all < 12 wt.%. Spectroscopic models were applied to 11,500 samples from western Victoria and harmonized to the GSM specified depth intervals using equal area splines. Clay minerals were then mapped using data mining model trees with a 10-fold cross validation to derive a mean prediction estimate and 90% prediction interval. Spatial models accounted for 26 to 77% of the total variation with kaolinite predictions for all 6 GSM depths ≥ 65%. Kaolinite is the dominant soil clay mineral of western Victoria for uplands and weathered volcanic terrains. Illite concentrations are higher where associated with weathered granitic plutons and in aeolian deposits of semi-arid environments. Smectite tends to occur associated with depressions of plains (volcanic and sedimentary). Further supplementation of additional sites and samples for landscapes with relatively sparse observations should contribute to refined and improved maps of these clay minerals. © 2016 Elsevier B.V.