ORCID Profile
0000-0002-4393-8635
Current Organisations
Central Queensland University
,
University of Tasmania
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Publisher: International Society for Horticultural Science (ISHS)
Date: 09-2016
Publisher: CRC Press
Date: 07-12-2018
Publisher: CSIRO Publishing
Date: 2018
DOI: 10.1071/RJ17124
Abstract: This study investigated the chemical characteristics of shallow (0–30 cm) soil profiles under shrubs in areas of dense encroachment and compared them with shallow soil profiles under nearby large trees. Consistent patterns of high soil acidity were found under shrubs, as well as lower litter alkalinity, lower relative concentrations of calcium (Ca2+), lower effective cation exchange capacity, and higher aluminium (Al3+) and sodium (Na+) in the soil profile compared with under trees. Soil pH (CaCl2) was strongly correlated with the Ca content of surface litter. These findings suggest that shrubs (which at most sites included the shrub form of tree species) cycle alkalinity differently from large and mature trees, resulting in high acidity in the shallow soil profile acidity, and possible loss of alkalinity via surface movement of material from areas of dense encroachment.
Publisher: International Society for Horticultural Science (ISHS)
Date: 09-2016
Publisher: International Society for Horticultural Science (ISHS)
Date: 09-2016
Publisher: Wiley
Date: 27-12-2022
DOI: 10.1111/EMR.12541
Abstract: The role of recreational fishers forming paths (routes of concentrated passage characterised by short vegetation or ground indentation) as they gain access to wilderness waterbodies has not been well documented in Australia. Recreational use for trout and tournament fly fishing has increased in the Central Plateau of Tasmania therefore, it is important to determine the human contribution to path formation and its potential consequences for bio ersity conservation in this area of high conservation value. We predicted that paths parallel to waterbodies experienced more human traffic than orthogonal paths. Across 36 sites at different distances from roads, a parallel and orthogonal path to lakeshore were s led using eight, 1 × 1 m quadrats randomly located along each path within a 10 × 10‐m plot. Recorded for each quadrat were the path widths, height difference between centre of paths and adjacent vegetation (path depth), vegetation types on and adjacent to paths, Bennetts Wallaby ( Notamacropus rufogriseus ) and Wombat ( Vombatus ursinus ) faecal numbers. General linear models indicated that path width was greater on parallel than orthogonal paths and declined with distance from roads. Path depth, however, was not affected by distance from roads but was shallower than orthogonal paths. Separate models used to test the potential effects of edge vegetation type, or the covariates Wallaby and Wombat scats did not have significant effects on‐path variables. Paths encircling or orthogonal to Central Plateau lakes appear different floristically to adjacent vegetation communities, nonetheless. Heath and tussock grassland were largely absent from paths, whereas grassland and herbfield communities were infrequently observed off paths. Herbfield and grassland are rarer communities than heath and tussock grassland, which, in the context of a lack of exposure to erosion, suggests a conservation benefit of paths at present usage levels. The human contribution to parallel path conditions is likely to be high, given the results from the study, so monitoring of change is desirable, especially if predicted increasing human activity eventuates in this area.
Publisher: Cambridge University Press (CUP)
Date: 12-08-2013
DOI: 10.1017/S1742170513000264
Abstract: Conventional soil management systems (SMS) use synthetic inputs to maximize crop productivity, which leads to environmental degradation. Organic SMS is an alternative that is claimed to prevent or mitigate such negative environmental impacts. Vegetable production systems rely on frequent tillage to prepare beds and manage weeds, and are also characterized by little crop residue input. The use of crop residues and organic fertilizers may counteract the negative impacts of intensive vegetable production. To test this hypothesis, we evaluated the effect of sweet corn ( Zea mays L. var. rugosa ) residue incorporation in a corn–cabbage ( Brassica oleracea L.) rotation on crop yields, nutrient uptake, weed biomass and soil nutrients for organic and conventional SMS in two contrasting soil types (a Chromosol and a Vertosol). Yields of corn and cabbage under the organic SMS were not lower than the conventional SMS, possibly due to the equivalent N, P and K nutrients applied. Macro-nutrient uptake between the organic and conventional SMS did not differ for cabbage heads. Corn residue incorporation reduced the average in-crop weed biomass in cabbage crops by 22% in 2010 and by 47% in 2011. Corn residue-induced inhibitions on weed biomass may be exploited as a supplementary tool to mechanical weed control for the organic SMS, potentially reducing the negative impacts of cultivation on soil organic carbon. Residue incorporation and the organic SMS increased the average total soil N by 7 and 4% compared with the treatments without residue and the conventional SMS, respectively, indicating the longer-term fertility gains of these treatments. Exchangeable K, but not Colwell P, in the soil was significantly increased by residue incorporation. The clayey Vertosol conserved higher levels of nutrients than the sandy Chromosol. Yields under organic SMS can match that of conventional SMS. Residue incorporation in soil improved soil nutrients and reduced weed biomass.
Publisher: CSIRO Publishing
Date: 2021
DOI: 10.1071/MF20069
Abstract: There is a growing body of research highlighting the importance of saltmarshes as habitats for fish for feeding, refuge from predation and reproduction. However, more work is needed on fish on vegetated marsh flats (or surfaces). We reviewed 60 studies that used 21 methods to s le fish assemblages on saltmarsh flats. Drop s lers, fyke nets and pop nets were most frequently employed, with considerably more studies being conducted in graminoid than succulent marsh. Reporting of s ling temporal and tidal details, environmental variables and fish attributes was inconsistent. Most of the papers focussed on one or more of conservation management, comparisons among habitat types, and the use of saltmarsh (including fish activity type or residency status). Important potential areas of research include the relationships between the fish assemblages of saltmarsh flats and coastal fisheries, the effects of invasive plant species and marsh restoration efforts in areas outside the United States, and the potential effects of sea-level rise on vegetated flats as fish habitat. S ling methods that provide density measures are likely to be most useful for most of this research. Thus, drop s lers and pop nets are an appropriate choice, the former in graminoid saltmarshes and the latter in succulent saltmarshes.
Publisher: CSIRO Publishing
Date: 2014
DOI: 10.1071/SR13295
Abstract: Vegetable production systems rely on frequent tillage to prepare beds and manage weeds, thereby accelerating losses of soil organic carbon (SOC). They are also characterised by scant crop residue input. Residue incorporation and organic fertiliser application could counteract SOC loss due to tillage. We tested this hypothesis in a Chromosol and a Vertosol in northern NSW, Australia, where the effects of incorporating sweet corn (Zea mays L. var. rugosa) residue in soil in a corn–cabbage (Brassica oleracea L.) rotation under either organic or conventional system on soil C fractions were studied during two rotation cycles (2 years). A laboratory experiment was conducted to isolate the effect of tillage on the soil organic matter (SOM) fractions, because both the residue-incorporated and without-residue treatments for organic systems received tillage for weed control in the field, whereas conventional systems did not. Residue incorporation increased particulate OC (POC) by 32% in the field experiment and 48% in the laboratory experiment, whereas dissolved OC was increased only in the organic system. Concentrations of mineral-associated OC (MOC) and total OC (TOC) were increased by residue incorporation in both field and laboratory experiments. Simulated tillage had a limited effect on POC, MOC and TOC, suggesting that cultivation for weed control may have only a minor effect on short-term SOM mineralisation rates. In both experiments, MOC accounted for ≥83% in the Vertosol and ≥73% in the Chromosol. Due to frequent tillage in vegetable production systems, physicochemical stabilisation of C predominates over protection through aggregation.
Publisher: MDPI AG
Date: 24-05-2022
DOI: 10.20944/PREPRINTS202205.0312.V1
Abstract: Very few multi-species or ecosystem comparisons of post-fire vertebrate herbivore activity and food preference exist to inform fire-management and conservation strategies. We inferred post-fire (1-3 years) native and introduced vertebrate herbivore activity and attraction to six erse temperate vegetation communities (grassland to rainforest) from scat counts. We hypothesised that where fire reduced herbaceous and grassy vegetation (& lsquo fodder& rsquo ), vertebrate herbivores would decline, and that post-fire preferences of native versus exotic herbivores would differ significantly. Instead, we found evidence for a & lsquo fire and fodder reversal phenomenon& rsquo whereby native macropod and exotic rabbit scats were more abundant after fire in consistently & lsquo fodder-poor& rsquo vegetation types (e.g wet forests) but more less abundant after fire in previously fodder-rich vegetation communities (e.g. grassland). Fodder cover predicted native macropod, wombat, and introduced deer activity and bareground cover was strongly associated with introduced herbivore activity only, with the latter indicating post-fire competition for food sources due to their abundance in high altitude open ecosystems. We therefore found environmental and vegetation predictors for each in idual species/group and suggest broadscale multi-environment, multispecies observations to be informative for conservation management in potentially overlapping post-fire niches.
Publisher: MDPI AG
Date: 08-2022
DOI: 10.3390/FIRE5040111
Abstract: Very few multi-species or ecosystem comparisons of post-fire vertebrate herbivore activity and food preference exist to inform fire management and conservation strategies. We inferred post-fire (1–3 years) native and introduced vertebrate herbivore activity and attraction to six erse temperate vegetation communities (grassland to rainforest) from scat counts. We hypothesised that where fire reduced herbaceous and grassy vegetation (‘fodder’), vertebrate herbivores would decline, and that post-fire preferences of native versus exotic herbivores would differ significantly. Instead, we found evidence for a ‘fire and fodder reversal phenomenon’ whereby native macropod and exotic deer scats were more abundant after fire in consistently ‘fodder-poor’ vegetation types (e.g., heath) but less abundant after fire in previously fodder-rich vegetation communities (e.g., grassland). Fodder cover predicted native macropod, wombat, and introduced deer activity and bare ground cover was strongly associated with introduced herbivore activity only, with the latter indicating post-fire competition for food sources due to their abundance in high-altitude open ecosystems. We, therefore, found environmental and vegetation predictors for each in idual species/group and suggest broadscale multi-environment, multispecies observations to be informative for conservation management in potentially overlapping post-fire niches.
Publisher: Wiley
Date: 04-2007
Publisher: CSIRO Publishing
Date: 2009
DOI: 10.1071/RJ08052
Abstract: Woody vegetation thickening occurs in agri-ecosystems worldwide, often with negative consequences for production. Dense Callitris glaucophylla (Joy Thomps. & L.A.S. Johnson) stands affect landscapes across NW NSW, Australia, and strategies to reduce tree density to levels which maintain bio ersity values alongside agricultural production are currently being sought. We investigated soil chemical and groundcover patterns associated with in idual small and large C. glaucophylla trees at six sites of variable management history and lithology in NW NSW, Australia. We posed two questions: (1) do in idual C. glaucophylla trees impose patterns on soil and groundcover (soil extractable P, C, N, S and pH, litter biomass, litter P and pasture cover), and, (2) if patterns exist, do they differ between tree sizes? Results showed that extractable P, C and pH decreased away from trees of both sizes, but significantly higher values were recorded adjacent to the stem of large trees. Litter biomass exhibited a strong site-related trend independent of soil variables. Positive correlations between litter and soil variables existed for some sites and not others, indicative of processes such as grazing which contribute to the transport of litter away from the tree. Irrespective of tree size ground-storey vegetation cover increased significantly away from the stem, presumably as a consequence of competition for soil water. Further results indicated that single C. glaucophylla trees enrich soils in patterns analogous to other species in similar environments worldwide. However, localised soil improvements must be weighed up against the negative effects of decreased groundcover associated with trees, and the potential for the species to re-seed prolifically into managed paddocks. Future research will discern the impact of in idual C. glaucophylla trees at higher densities, where soil patterning may be modified by intense within-stand competition.
Publisher: MDPI AG
Date: 19-11-2019
Abstract: Gorse (Ulex europeus L.) is a woody legume and invasive woody weed that has been introduced to temperate pastoral landscapes worldwide. Despite the apparent cosmopolitan distribution of gorse across much of the temperate agroecological landscapes of the world, research and practice pertaining to the management of gorse has been largely constrained to single-treatments, regions, or timeframes. Gorse eradication has been widely attempted, with limited success. Using the PRISMA (preferred reporting items for systematic reviews and meta-analysis) method and a quasi-metanalytical approach, we reviewed the seminal ~299 papers pertaining to gorse management. We identified (i) the ecological characteristics of the species that predispose gorse to behaving invasively, and (ii) the success of management actions (from a plant ecological life history perspective) in reducing weed vigour and impact. A broad ecological niche, high reproductive output, propagule persistence, and low vulnerability to pests allow for rapid landscape exploitation by gorse throughout much the world. Additionally, there are differences in flowering duration and season in the northern and southern hemisphere that make gorse particularly pernicious in the latter, as gorse flowers twice per year. The implications of these life history stages and resistance to environmental sieves after establishment are that activity and efficacy of control is more likely to be favourable in juvenile stages. Common approaches to gorse control, including herbicides, biological controls, and fire have not been ubiquitously successful, and may in fact target the very site resources—sward cover, soil stability, hydrological balance—that, when degraded, facilitate gorse invasion. Ongoing seedling regeneration presents difficulties if eradication is a goal, but facilitated competition may reduce costs via natural suppression. Mechanical methods of gorse removal, though highly successful, induce chronic soil erosion and land degradation and should hence be used sparingly.
Publisher: Wiley
Date: 16-08-2014
DOI: 10.1002/EJSP.2059
Publisher: Springer Science and Business Media LLC
Date: 10-06-2006
Publisher: Springer Science and Business Media LLC
Date: 07-07-2020
Publisher: Wiley
Date: 19-06-2014
DOI: 10.1111/SUM.12130
No related grants have been discovered for Melinda McHenry.