Occurrence of silica in the natural waters of the Huntley-Robertson district, southern New South Wales

1972 ◽  
Vol 23 (2) ◽  
pp. 105 ◽  
Author(s):  
M Johnson ◽  
WD Johnson
Keyword(s):  
Surface Waters ◽  
Natural Waters ◽  
Surface Reaction ◽  
New South ◽  
Equilibrium Concentration ◽  
Soil Surface ◽  
Core Material ◽  
South Wales ◽  
Rapid Dissolution ◽  
Soluble Silica

The silica concentrations of both ground and surface waters from the Triassic Hawkesbury Sandstone were found to range from 3.0 to 12.0 p.p.m. Samples of soil, surface bedrock, and fresh core material were leached with water, and the results of chemical analyses carried out on the subsequent solutions are discussed with reference to the source of the silica in solution. A time study of the release of soluble silica from sandstone indicated rapid dissolution within the first few days, with equilibrium concentration being reached after a period of several weeks due to inhibiting surface reaction on the mineral grains. A possible explanation, based on the effects of weathering and the impervious nature of the sandstone, is suggested to account for the similarity between the silica concentrations of surface water and groundwater.

An Aerial Survey of 3 Game Species of Waterfowl (Family Anatidae) Populations in Eastern Australia

1986 ◽  
Vol 13 (2) ◽  
pp. 213 ◽  
Author(s):  
LW Braithwaite ◽  
M Maher ◽  
SV Briggs ◽  
BS Parker
Keyword(s):  
Surface Waters ◽  
New South ◽  
New South Wales ◽  
Aerial Survey ◽  
Game Species ◽  
South Wales ◽  
Black Duck ◽  
The Pacific ◽  
Eastern Australia ◽  
Central Eastern

Populations of waterfowl of three game species, the Pacific black duck Anus superciliosa, grey teal A. gibberifrons, and maned duck Chenonetta jubata, were assessed by aerial survey in October 1983 within a survey region of 2 697 000 km2 of eastern Australia. The numbers of each species were assessed on all surface waters of over 1 ha, and on a sample of smaller surface waters within 10 survey bands each 30 km wide and spaced at intervals of 2� latitude from 20�30' to 38�30'S. The area within the survey bands was 324 120 km2, which gave a sampling intensity of 12.0% of the land surface area. The area of features shown as wetlands or water impoundments within the survey bands on 1 : 2 500 000 topographic maps was 19 200 km2 or 11.2% of the total area of these features in the survey region. The area of surface waters surveyed was assessed at 465 300 ha. Assessments of populations of each species were tallied for wetlands by grid cells of 6 min of 1� longitude along the survey bands (258-309 km2 depending on latitude). Distributions were then mapped, with log*10 indices of populations in each cell. Distributions of the black duck and grey teal showed a pattern of intense aggregation in limited numbers of cells, that of the maned duck was more evenly distributed. The major concentrations of the Pacific black duck were recorded in northern New South Wales and the south-eastern, western, central eastern and central coastal regions of Queensland; those of the grey teal were in south-western, western and northern New South Wales and central-eastern Queensland; the maned duck was broadly distributed over inland New South Wales with the exception of the far west, inland southern Queensland, and central northern Victoria.

What lies beneath? The pattern and abundance of the subterranean tuber bank of the invasive liana cat's claw creeper, Macfadyena unguis-cati (Bignoniaceae).

2009 ◽  
Vol 57 (2) ◽  
pp. 132 ◽  
Author(s):  
Olusegun O. Osunkoya ◽  
Karina Pyle ◽  
Tanya Scharaschkin ◽  
Kunjithapatham Dhileepan
Keyword(s):  
New South ◽  
Soil Surface ◽  
Stem Density ◽  
Riparian Areas ◽  
South Wales ◽  
Large Trees ◽  
Tuber Traits ◽  
Standing Vegetation ◽  
Multiple Stems ◽  
Environmental Weed

Cat’s claw creeper, Macfadyena unguis-cati (L.) Gentry (Bignoniaceae) is a major environmental weed of riparian areas, rainforest communities and remnant natural vegetation in coastal Queensland and New South Wales, Australia. In densely infested areas, it smothers standing vegetation, including large trees, and causes canopy collapse. Quantitative data on the ecology of this invasive vine are generally lacking. The present study examines the underground tuber traits of M. unguis-cati and explores their links with aboveground parameters at five infested sites spanning both riparian and inland vegetation. Tubers were abundant in terms of density (~1000 per m2), although small in size and low in level of interconnectivity. M. unguis-cati also exhibits multiple stems per plant. Of all traits screened, the link between stand (stem density) and tuber density was the most significant and yielded a promising bivariate relationship for the purposes of estimation, prediction and management of what lies beneath the soil surface of a given M. unguis-cati infestation site. The study also suggests that new recruitment is primarily from seeds, not from vegetative propagation as previously thought. The results highlight the need for future biological-control efforts to focus on introducing specialist seed- and pod-feeding insects to reduce seed-output.

Effects of depth and time of sowing on emergence of Danthonia richardsonii Cashmore and Danthonia linkii Kunth

1993 ◽  
Vol 44 (6) ◽  
pp. 1311 ◽  
Author(s):  
GM Lodge ◽  
AJ Schipp
Keyword(s):  
New South ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Maximum Temperature ◽  
Sowing Time ◽  
Sand Mixture ◽  
South Wales ◽  
Seed Field ◽  
Dry Conditions ◽  
Soil Temperatures

Two experiments examined the effects of sowing time and depth (surface and 10, 25, 50 mm) on emergence of Danthonia richardsonii Cashmore and Danthonia linkii Kunth. Experiment 1 was conducted from January to December 1990 on a loam/sand mixture in boxes. Emergence was highest in both species for seeds sown onto the soil surface in summer and autumn (P < 0.05). Sowing at any depth at any time of the year, or surface sowing in winter and spring, markedly reduced emergence. Experiment 2 was conducted in the field at Tamworth, northern New South Wales from September 1991 to August 1992, on a red brown earth and a black earth. This study confirmed that emergence in both species was highest from surface sown seed. Field emergence was lowest in winter, but in contrast to experiment 1, it was higher in spring, particularly on the black earth. Seedling emergence appeared to be related to mean maximum temperature, decreasing in winter as it declined below 20�C, and increasing in spring when it was greater than 23�C. Differences in seed weight were reflected in emergence of D. richardsonii and D. linkii in experiment 1. Similar emergence was recorded for the loamlsand mixture and sand, indicating that there was little effect of texture. Phalaris aquatica L. cv. Sirosa surface sown in December had lower emergence ( P < 0.05) than both Danthonia spp., but emergence of this larger seeded cultivar was higher at depths of 10 and 25 mm. Laboratory studies to determine reasons for the low emergence of D. richardsonii and D. linkii from depth, indicated that neither had an obligate light requirement for germination. Depth, however, reduced germination (P < 0.05) compared with surface sowing of seed. Seedlings at depth also were observed to have slower rates of shoot and root elongation. In the field, the most successful establishments of D. richardsonii and D. linkii seedlings are likely to occur from surface sowings in April and May. Sowing in spring may also be possible if mean maximum soil temperatures exceed 23�C, and seedlings can establish before the onset of hot, dry conditions in summer.

Biodiversity implications of water management in the Great Artesian Basin.

1998 ◽  
Vol 20 (2) ◽  
pp. 275 ◽  
Author(s):  
JC Noble ◽  
MA Habermehl ◽  
CD James ◽  
J Landsberg ◽  
AC Langston ◽  
...  
Keyword(s):  
Natural Waters ◽  
Biological Diversity ◽  
New South ◽  
Grazing Impact ◽  
Artesian Basin ◽  
Land Type ◽  
Great Artesian Basin ◽  
South Wales ◽  
High Conservation ◽  
Negative Impacts

The Great Artesian Basin (GAB) underlies a vast, mainly arid, region where most of the indigenous biota are not dependent upon surface water. In contrast, an important minority is dependent on refuges such as mound springs and their associated wetlands. In some parts of the GAB, such as western New South Wales, many springs have either ceased to flow, or are now barely detectable, because the proliferation of artesian waterbores has reduced groundwater pressures. Because of the rarity of species endemic to mound springs, and the damage they have suffered since pastoral settlement, emphasis should be directed towards conservation and possible rejuvenation of these ecosystems. Provision of artificial sources of water allows more widespread grazing by livestock, larger native and feral herbivores, thereby posing threats to native plants and animals that do not use the water. Because of the proliferation of artificial waters and the grazing they allow, terrestrial grazing-sensitive species now appear to be confined to tiny patches in the landscape. Some nature reserves within the GAB retain numerous artificial sources of water. Most of these should be closed over time to reduce negative impacts on grazing-sensitive plants and animals, especially where these species are inadequately protected elsewhere. In those regions where the ratio of artificial to natural waters is still low, consideration should be given to balancing provision of water for livestock with conservation of biological diversity, by maintaining a patchwork of areas remote from water. In regions where the density of artificial waters is high, conservation of biodiversity on freehold and leasehold lands might be enhanced with a mix of approaches accommodating the needs of the biota and the aspirations of landholders, tailored according to land type and condition. Key words: Great Artesian Basin, biological diversity, mound springs, refuges, rare biota, grazing impact, conservation management, groundwater.

Some investigations into soil and vegetation relationships associated with alkaline-saline soil surfaces in the Walcha area, Northern Tablelands, New South Wales

1995 ◽  
Vol 46 (1) ◽  
pp. 209 ◽  
Author(s):  
KH Kreeb ◽  
RDB Whalley ◽  
JL Charley
Keyword(s):  
Cynodon Dactylon ◽  
New South ◽  
New South Wales ◽  
Soil Surface ◽  
Tree Planting ◽  
Soil Parameters ◽  
Alkali Cations ◽  
Grazing Land ◽  
South Wales ◽  
Wide Range

The characteristics of the soil, vegetation and groundwater at a dryland salinity site on Miramoona, a property near Walcha on the Northern Tablelands of New South Wales, were investigated. Soil parameters measured at 23 points along a 200 m transect were highly correlated with the pattern of vegetation. Of overriding significance was soil pH, which varied from a high of over 10 on bare areas delineated by Critesion marinum and Cynodon dactylon to a low of less than 5 on grazing land supporting the growth of a wide range of pasture species. The bare areas were characterized by alkalinity. While they were sodic at all depths measured, they were only marginally saline and then only at the soil surface. The chemical composition of the groundwater collected from three piezometer tubes varied quite markedly over the site. It is hypothesized that the presence of alkaline bare areas on the Northern Tablelands is not a new problem, but rather the natural result of alternating wet and dry periods which have induced accumulation of carbonates and bicarbonates of the alkali cations, notably sodium. Drainage of the original perched swamps by the early landholders, tree clearing and the grazing of domestic livestock would have accelerated the process since European settlement. However, tree planting would appear unlikely to have any impact on the reclamation process in the short term. A more viable option would be the recreation of the original swamps in suitable situations, although this solution would create problems for grazing management.

Baseline trace metal concentrations in New South Wales coastal waters

1998 ◽  
Vol 49 (3) ◽  
pp. 203 ◽  
Author(s):  
Simon C. Apte ◽  
Graeme E. Batley ◽  
Ronald Szymczak ◽  
Paul S. Rendell ◽  
Randall Lee ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Trace Metal ◽  
Surface Waters ◽  
Coastal Waters ◽  
New South ◽  
New South Wales ◽  
Metal Concentrations ◽  
South Wales ◽  
The Pacific ◽  
The Pacific Ocean

Concentrations of ten trace elements at five localities in New South Wales coastal waters were measured by ultratrace sampling and analysis. Mean concentrations of cadmium (2.4 ng L-1), copper (31 ng L-1), nickel (180 ng L-1), lead (9 ng L-1) and zinc (<22 ng L-1) are among the lowest reported in the Southern Hemisphere and are consistent with recent oceanographic data for the surface waters of the Pacific Ocean. Waters from the southernmost sampling locality (Eden) contained higher phosphate, silicate, cadmium and nickel, but lower chromium concentrations than waters from the other four localities, reflecting the inputs of water from the Tasman Sea in the south compared with the dominance of waters from the Coral Sea along the rest of the coast. Cadmium concentrations were positively correlated with both phosphate and silicate. Chromium and lead concentrations were also significantly correlated. It is likely that a major source of lead is atmospheric deposition. The trace metal concentrations were comparable to those in the surface waters of the Pacific Ocean, indicating that fluvial inputs or processes occurring in the coastal margin were of limited importance in determining trace metal concentrations.

Influence of cropping on the population of a native earthworm and consequent effects on hydraulic properties of vertisols

Soil Research ◽  
1995 ◽  
Vol 33 (6) ◽  
pp. 995 ◽  
Author(s):  
JJ Friend ◽  
KY Chan
Keyword(s):  
Population Density ◽  
New South ◽  
Soil Surface ◽  
Infiltration Rate ◽  
Shrinkage Cracks ◽  
South Wales ◽  
Natural Pasture ◽  
Earthworm Population ◽  
Moisture Conditions ◽  
Brown Clay

Population density of Heteroporodrilus mediterreus, a large native earthworm found on the Mitchell grassland (Astrebla lappacea) on the Vertisol plains near Walgett, New South Wales, was investigated at two sites (brown and grey clays). Maximum earthworm activity at the soil surface layer was observed during winter (July/August) corresponding to more favourable soil moisture conditions. The highest earthworm population density (7.5 m-2) and biomass (0.89 t ha-1) were detected at the brown clay site under natural pasture. Populations were much lower (by two thirds in the brown clay) and the proportion of immature worms was much higher in the cropped soils than in the pasture soils. Current wheat cropping practices involving long fallowing and excessive cultivation during the period when earthworms are active at the surface are the possible causes of the reduction in population. Disc permeameter measurements compared with infiltration through single earthworm holes showed that the earthworm channels contributed significantly to the movement of water into the subsoil. Their persistence under wet conditions, even after closure of shrinkage cracks, suggests they are also important in maintaining subsoil aeration. Significant reductions in sorptivity and infiltration rate were observed in the cropped soils.

Regeneration of annual winter legumes at Tamworth, New South Wales

1974 ◽  
Vol 14 (66) ◽  
pp. 57 ◽  
Author(s):  
MW Hagon
Keyword(s):  
Seed Production ◽  
New South ◽  
New South Wales ◽  
Soil Surface ◽  
Moisture Stress ◽  
Late Spring ◽  
South Wales ◽  
Hard Seeds ◽  
Improved Cultivars

The seed production and regeneration of a range of naturalized and introduced cultivars of annual clovers and medics was studied at Tamworth, New South Wales, between 1971 and 1973. Seed production was correlated with maturity grading within species only when moisture stress occurred in late spring. The proportion of seed lost as summer seedlings and the proportion of unrecovered seed were greater the lower the level of hardseededness. A greater proportion of unrecovered seed was recorded for those cultivars which bore their burrs at the soil surface. As a group the medics had a higher proportion of residual hard seeds than did the clovers. The results are discussed in relation to the likely persistence of improved cultivars compared to the successful persistence of the naturalized medics and clovers in the Tamworth district.

Preliminary observations on the effect of removal of black bluebush (Maireana pyramidata) and Pearl Bluebush (M. sedifolia) on shrub regeneration, herbage production and erosion potential.

1985 ◽  
Vol 7 (2) ◽  
pp. 103
Author(s):  
GJ Tupper ◽  
WJ Muller
Keyword(s):  
Wind Erosion ◽  
New South ◽  
Soil Surface ◽  
Critical Value ◽  
Mechanical Removal ◽  
South Wales ◽  
Erosion Index ◽  
Relationship Of ◽  
The Relationship ◽  
Over Time

The effects of mechanical removal of shrub tops and grazing on two bluebush communities, one with Maireana pyramidata (black bluebush)and the other with M. pyramidata and M. sedifolia (pearl bluebush) as co-dominants, were examined on the western edge of the Riverine Plain in New South Wales Measurements were made on shrub regeneration, the relationship of shrub units to a critical value for an erosion index, the change in soil surface levels, and the growth of herbaceous plants over time Shrub regeneration was slower under grazed than ungrazed conditions and occurred mainly from basal shoots of established plants rather than from seedling establishment. Herbage yields Increased on the mounds previously occupied by shrubs, whereas production between shrubs was not affected by shrub removal. After four years there was sufficient shrub growth to prevent wind erosion, except on the cleared and grazed plot at the M. sedifolia site.

Factors contributing to the acid sulfate soil scalding process in the coastal floodplains of New South Wales, Australia

Soil Research ◽  
2004 ◽  
Vol 42 (6) ◽  
pp. 587 ◽  
Author(s):  
Mark A. Rosicky ◽  
Leigh A. Sullivan ◽  
Peter G. Slavich ◽  
Mike Hughes
Keyword(s):  
New South ◽  
New South Wales ◽  
Pyrite Oxidation ◽  
Soil Surface ◽  
Soil Parameters ◽  
Soil Core ◽  
Acid Sulfate Soil ◽  
Vegetative Cover ◽  
Acid Sulfate ◽  
South Wales

Acid sulfate soil (ASS) scalds are persistently bare areas of land, occurring in the coastal backswamps of New South Wales (NSW), Australia. This study aims to understand why particular areas become ASS scalds, while adjacent areas remain vegetated. Some important soil parameters are compared and field observations are summarised. Soil core sampling in both ASS-scalded land and surrounding areas of permanently vegetated paddocks has demonstrated similar pyrite concentrations and depth occurrence, soil salinity, and soil acidity (pH). As conditions are similar beneath both vegetated and non-vegetated land, there must be some additional factors influencing which areas become denuded. Several disparate (usually human-induced) events were found to cause initial loss of vegetative cover. Once the soil is bare, surface evaporation causes toxic solutes to build up quickly at the soil surface and ASS scalding is perpetuated. Some of the intervening events include fire, flood, flood-scouring, deliberate topsoil removal, surface pyrite oxidation, saltwater inundation of freshwater paddocks, saltwater exclusion from saltmarsh or mangroves, changes to the vegetation regimes, excessive vehicular traffic, and over-grazing. Backswamp management needs to ensure that land underlain by shallow pyritic layers (or with soil-water that is enriched with the toxic by-products of pyrite oxidation) is not laid bare by accident or design. Similar soil chemical conditions underlying both ASS scalds and the surrounding permanently vegetated paddocks suggest that much larger areas are potentially at risk of ASS scalding.

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