Effects of grazing and depth on two wetland plant species

1994 ◽  
Vol 45 (8) ◽  
pp. 1387 ◽  
Author(s):  
SJ Blanch ◽  
MA Brock
Keyword(s):  
Morphological Changes ◽  
New South ◽  
Shoot Length ◽  
Water Levels ◽  
Growth Responses ◽  
Ground Biomass ◽  
South Wales ◽  
Shoot Production ◽  
Below Ground ◽  
Total Plant

Wetland plants in Llangothlin Lagoon, northern New South Wales, are subject to grazing and trampling by cattle, sheep and waterbirds and to fluctuating water levels. Myriophyllum variifolium J. Hooker, an aquatic dicotyledon with dispersed meristems, exhibited different morphological changes to the emergent monocotyledon Eleocharis acuta R. Br, under simulated and natural grazing at different water depths. Responses were principally determined by position and number of meristems. Growth point production (numbers of shoots and branches) increased under light, frequent clipping (25% every 14 or 7 days) in non-submerged plants only. Node production, total plant or shoot length, and above- and below-ground biomass decreased under similar clipping treatments. E. acuta did not increase shoot production or above-ground biomass under any clipping treatment, and only for the lightest clipping treatment (clipped once to 7 cm when non-submerged) was no decrease in total shoot length observed. More intense and frequent clipping treatments and submersion to 15 cm prevented both species from replacing lost tissues. Interaction between clipping and submersion occurred in both species, indicating that growth responses are complex. The distribution and abundance of the two species reflect the greater tolerance of M. variifolium than E. acuta to grazing and inundation. Low intensities of cattle and sheep grazing may be beneficial by increasing species diversity.

scholarly journals Below-ground biomass in some intertidal wetlands in New South Wales.

2009 ◽  
Vol 4 (2) ◽  
pp. 56 ◽  
Author(s):  
W Lichacz ◽  
S Hardiman ◽  
R T Buckney
Keyword(s):  
New South ◽  
New South Wales ◽  
Ground Biomass ◽  
South Wales ◽  
Below Ground ◽  
Intertidal Wetlands

The growth of improved pastures on acid soils. 1. The effect of superphosphate and lime on soil pH and on the establishment and growth of phalaris and lucerne

1985 ◽  
Vol 25 (1) ◽  
pp. 149 ◽  
Author(s):  
LJ Horsnell
Keyword(s):  
Soil Ph ◽  
New South ◽  
Acid Soils ◽  
Potassium Sulfate ◽  
First Year ◽  
Growth Responses ◽  
South Wales ◽  
Large Growth ◽  
Lime Application ◽  
Effect Of Surface

The response of improved pastures to the application of superphosphate is low on the acid sedimentary soils, of the Southern Tablelands of New South Wales, which contain high levels of exchangeable aluminium. An investigation was made into the effect of surface-applied fertilizers on soil pH and on the establishment and growth of lucerne and phalaris on these soils. At 6 weeks after the application of gypsum, superphosphate, or superphosphate plus potassium sulfate, soil pH (H2O) had decreased markedly. This effect extended to a depth of 20 cm, but decreased with time. Initially, lime application increased the pH of the surface soil only. When superphosphate was applied with lime the pH of the soil under the lime layer decreased to the same level as that found in the soil treated with superphosphate alone. Lime, however, had penetrated into the subsoil 102 weeks after application and substantially more so after 13 years. Soil pH (0.01 M CaCl2) was not depressed by the application of fertilizers. Growth and persistence of both species in the first summer were poor, but growth responses to phosphorus, lime and nitrogen increased after the first year. Lucerne showed large growth responses to lime, greater than those found on plots receiving nitrogen fertilizer. Lime reduced aluminium levels both in lucerne plants and in soil. It is suggested that the slow penetration of lime into the soil, the relatively quick effect of superphosphate in increasing subsoil acidity, and high soil aluminium levels are together responsible for the poor persistence and slow growth of both lucerne and phalaris in the early stages. The subsequent large dry matter responses of lucerne to lime are possibly related to increased nitrogen fixation and a lowering of plant and soil aluminium levels. It is suggested that the lime responses of phalaris are also related to lower aluminium levels.

Zooplankton species richness and abiotic conditions in Thirlmere Lakes, New South Wales, Australia, with reference to water-level fluctuations

2020 ◽  
Vol 41 (1) ◽  
pp. 107-123
Author(s):  
Tsuyoshi Kobayashi ◽  
Martin Krogh ◽  
Hiroyuki ◽  
Russell J. Shiel ◽  
Hendrik Segers ◽  
...  
Keyword(s):  
Species Richness ◽  
Water Level ◽  
Lake Water ◽  
New South ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Zooplankton Species ◽  
Abiotic Conditions ◽  
Lake Water Level ◽  
South Wales

Water-level fluctuations can have significant effects on lake biological communities. Thirlmere Lakes are a group of five interconnected lakes located near Sydney. Water levels in Thirlmere Lakes have fluctuated over time, but there has been a recent decline that is of significant concern. In this study, we examined over one year the species composition and richness of zooplankton (Rotifera, Cladocera and Copepoda) and abiotic conditions in Lakes Nerrigorang and Werri Berri, two of the five Thirlmere lakes, with reference to lake water level. We recorded a total of 66 taxa of zooplankton, with the first report of the rotifer Notommata saccigera from Australia, and the first report of the rotifers Keratella javana, Lecane rhytida and Rousseletia corniculata from New South Wales. There was a marked difference in abiotic conditions between the two lakes, with more variable conditions in Lake Nerrigorang. There was a significant positive correlation between zooplankton species richness and lake water level but only for Lake Nerrigorang. Although the two lakes are closely situated and thought to be potentially connected at high water levels, they show distinct ecological characters and the effect of water-level fluctuations on zooplankton species richness seems to differ between the lakes.

Above- and below-ground biomasses of two species of mangrove on the Hawkesbury River estuary, New South Wales

1997 ◽  
Vol 48 (2) ◽  
pp. 147 ◽  
Author(s):  
Neil Saintilan
Keyword(s):  
New South ◽  
New South Wales ◽  
River Estuary ◽  
Avicennia Marina ◽  
Above Ground Biomass ◽  
Aegiceras Corniculatum ◽  
South Wales ◽  
Below Ground ◽  
Mangrove Communities ◽  
Intertidal Environments

Above- and below-ground biomasses of two species of mangrove, Avicennia marina and Aegiceras corniculatum, were estimated in a range of intertidal environments along the Hawkesbury River. Estimates of biomass of Avicennia communities in freshly accreted brackish substrata were in the order of 40 kg m–2, the highest figure ever recorded for temperate mangrove communities. The above-ground biomass communities of each species declined with increasing substratum salinity, whereas root/shoot ratios increased with increasing substratum salinity.

Role of the crayfish Cherax destructor clark as food for trout in Lake Eucumbene, New South Wales

1983 ◽  
Vol 34 (3) ◽  
pp. 407 ◽  
Author(s):  
RA Faragher
Keyword(s):  
Rainbow Trout ◽  
Brown Trout ◽  
Salmo Trutta ◽  
New South ◽  
New South Wales ◽  
Water Levels ◽  
Size Analysis ◽  
Fish Length ◽  
Freshwater Crayfish ◽  
South Wales

The freshwater crayfish C. destructor was a major dietary item for brown trout, Salmo trutta L., and rainbow trout, S. gairdneri Richardson, in Lake Eucumbene, New South Wales. The incidence of crayfish in the diet increased, particularly in brown trout, over the period 1972-1977. The proportion of the trout's diet comprising C. destructor increased with length of brown trout but not with length of rainbow trout. The size of crayfish ingested was postively correlated with fish length for both species of trout, although rainbow trout tended to ingest smaller crayfish than brown trout of equivalent size. Analysis of the crayfish's diet revealed predominantly plant material. Spawning by the crayfish was apparently confined to the period December-April. The abundance of C. destructor in Lake Eucumbene was apparently low until about 1970 but increased between 1972-1977. A decline in the average size of brown and rainbow trout in the angler catch occurred from 1959-1960 until 1977-1978. Hypotheses are suggested for the increase of the crayfish population since impoundment of the lake (1957). Factors considered include predation by trout and the biology of the crayfish, particularly related to its occurrence in this lake, which has fluctuating water levels and a short season suitable for growth and spawning.

Population monitoring of the vulnerable wallum sedge frog (Litoria olongburensis) in north-eastern New South Wales

2005 ◽  
Vol 53 (3) ◽  
pp. 185 ◽  
Author(s):  
B. D. Lewis ◽  
R. L. Goldingay
Keyword(s):  
New South ◽  
Environmental Parameters ◽  
Population Monitoring ◽  
Water Levels ◽  
Successful Recruitment ◽  
South Wales ◽  
North Eastern ◽  
Frog Species ◽  
Population Indices ◽  
The Stability

The literature on the population ecology of Australian frogs provides relatively few accounts of population monitoring. This has hampered our ability to understand how frog populations respond to dynamic rainfall patterns and to determine the stability of populations of threatened frog species. We conducted biannual monitoring of the wallum sedge frog (Litoria olongburensis) along transects at 10 sites over a 4-year period (1996–2000). We recorded six environmental parameters to assess their influence on our population indices. Monitoring of transects indicated that populations were rarely stable and fluctuated from year to year. Counts of adults were negatively influenced by rain during the previous day but positively influenced by rain during the previous week. This suggests that timing of recent rainfall has a differing influence on habitat use by adult frogs. Counts of adults were also significantly influenced by site and census period. Numbers of juveniles were influenced by rain during the previous three months, which may suggest that successful recruitment depends on higher water levels in the sedge swamps. Counts of juveniles were also significantly influenced by census period. Our analysis reveals that, after controlling for the influence of rainfall, the number of adult frogs per census varied between 10 and 20 per transect. The number of juveniles varied between 5 and 15 per transect per census. We conclude that the wallum sedge frog across the geographic range of our sites was not in decline during our monitoring period. In light of our findings we provide a review on population monitoring of Australian frogs.

Shallow groundwaters in weathered volcanic, granitic and sedimentary rocks in relation to dryland salinity in southern New South Wales

Soil Research ◽  
1985 ◽  
Vol 23 (3) ◽  
pp. 355 ◽  
Author(s):  
RH Gunn
Keyword(s):  
Sodium Chloride ◽  
New South ◽  
Ionic Composition ◽  
New South Wales ◽  
Sedimentary Rocks ◽  
Water Levels ◽  
Granitic Rocks ◽  
Secondary Salinization ◽  
South Wales ◽  
Salt Affected Soils

Soils affected by secondary salinization were studied in six areas on the Southern Tablelands of New South Wales. All the salt-affected areas are underlain by, or occur in close proximity to, deeply weathered volcanic, granitic and sedimentary rocks which commonly contain stores of soluble salts, dominantly sodium chloride. The chemical composition of shallow groundwaters in the areas was monitored by piezometers for periods of up to two years. Water levels in the piezometers responded rapidly to rainfall, but the ionic composition of the waters generally remained fairly uniform. All waters are dominated by sodium chloride; those with the highest contents occurred in volcanic and granitic rocks, followed by Ordovician sediments and the lowest contents were in Silurian sediments. The chlorine contents in samples of weathered rocks follow a similar sequence. Electron microprobe analyses indicate that the chlorine-bearing minerals in the unaltered rocks are principally biotite, hornblende and potassium, sodium and calcium feldspars. No salt-affected soils were found in areas underlain by unweathered rocks.

Features of the growth and mineral nutrition of Noogoora burr (Xanthium occidentale Bertol.), a noxious weed in central New South Wales

1983 ◽  
Vol 34 (2) ◽  
pp. 155 ◽  
Author(s):  
PJ Hocking
Keyword(s):  
Dry Matter ◽  
New South ◽  
New South Wales ◽  
High Capacity ◽  
Crop Species ◽  
Plant Parts ◽  
South Wales ◽  
Fruit Maturity ◽  
Total Plant ◽  
Noxious Weed

Aspects of the growth and accumulation, partitioning and redistribution of selected minerals in the weed Xanthium occidentale (Noogoora burr) are described for a population from central New South Wales. Plants required 240 days from emergence to fruit maturity. Uptake of most elements occurred until midway through fruit development. Rates of nutrient intake by roots were similar to those of some crop species. Fruits made up of 46% of the dry matter of a mature plant and contained 58- 79 % of its P, N and S, 18-39 % of the Cl, Na, Mg and K, but < 19 % of the Ca and Mn. Dead leaves had the greatest proportion of the total plant Mg, Na, Cl, and especially Mn and Ca. The elements P, N and S were redistributed from above-ground parts to the fruits with efficiencies of 43-63 %, but there was negligible (< 10%) redistribution of Cl, Mn, Ca and Na. Redistribution from above-ground plant parts could have provided 43-55 % of the dry matter, N, P, K, S and Mg accumulated by fruits. The amount of free nitrate-N stored in stems and leaves decreased rapidly during fruit filling. Leaves were more important than stems as a source of nutrients for redistribution, but the stem was more important for redistribution of dry matter. Cotyledons of parent seeds redistributed dry matter and nutrients to seedlings with net efficiencies ranging from 16-97 %, but gained Cl and Ca. Redistribution from cotyledons provided 2-45 % of the amount of a nutrient accumulated by seedlings. Seeds made up 38 % of the fruit dry matter and had 60-93% of its S, P and N, but only small proportions of its Ca, Cl, Na and Mn. Seeds had 38% protein and 39% oil. It is concluded that the high capacity of Noogoora burr to accumulate reserves of nutrients for redistribution to fruits contributes to its success as a weed.

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