Charophyte Occurrence, Seed Banks and Establishment in Farm Dams in New South Wales

1999 ◽  
Vol 47 (3) ◽  
pp. 437 ◽  
Author(s):  
Michelle T. Casanova ◽  
Margaret A. Brock
Keyword(s):  
New South ◽  
New South Wales ◽  
Water Clarity ◽  
High Water ◽  
Seed Banks ◽  
Water Bodies ◽  
Dissolved Phosphorus ◽  
South Wales ◽  
High Turbidity ◽  
Chara Australis

Farm dams are an important and common water resource in rural Australia. They provide relatively permanent surface water for stock and wildlife. They typically have high turbidity and high levels of disturbance by stock. The occurrence of charophytes in these water bodies was examined, as well as the conditions under which they germinated and established. Charophytes were found in 15% of 65 farm dams surveyed in two regions in New South Wales, Australia. However, charophytes germinated from 64.5% of farm dam seed banks sampled (n = 17). Species found were Chara australis R.Br., C. fibrosa Agardh ex Bruzelius, C. globularis Thuillier, C. muelleri A.Br., Nitella cristata A.Br. and N. tasmanica A.Br. Farm dams in which charophytes were found both in the survey and in the seed bank had lower turbidity, lower dissolved phosphorus levels and more extensive submerged plant communities than average. Charophytes established from the seed banks under experimentally induced water regimes when high water clarity was maintained and the disturbance of stock grazing was removed. Farm dams can support populations of perennial and annual charophyte species, and provide a habitat that is less available in naturally occurring shallow water bodies of the regions.

Seed production and seedling emergence of Giant Parramatta grass on the north coast of New South Wales

1996 ◽  
Vol 36 (3) ◽  
pp. 299 ◽  
Author(s):  
TS Andrews ◽  
RDB Whalley ◽  
CE Jones
Keyword(s):  
Seed Production ◽  
Seed Bank ◽  
New South ◽  
New South Wales ◽  
Seed Banks ◽  
North Coast ◽  
The North ◽  
South Wales ◽  
Seed Fall ◽  
The Impact

Inputs and losses from Giant Parramatta grass [GPG, Sporobolus indicus (L.) R. Br. var. major (Buse) Baaijens] soil seed banks were quantified on the North Coast of New South Wales. Monthly potential seed production and actual seed fall was estimated at Valla during 1991-92. Total potential production was >668 000 seeds/m2 for the season, while seed fall was >146000 seeds/m2. Seed fall >10000 seeds/m2.month was recorded from January until May, with further seed falls recorded in June and July. The impact of seed production on seed banks was assessed by estimating seed banks in the seed production quadrats before and after seed fall. Seed banks in 4 of the 6 sites decreased in year 2, although seed numbers at 1 damp site increased markedly. Defoliation from mid-December until February, April or June prevented seed production, reducing seed banks by 34% over 7 months. Seed banks in undefoliated plots increased by 3300 seeds/m2, although seed fall was estimated at >114 000 seeds/m2. Emergence of GPG seedlings from artificially established and naturally occurring, persistent seed banks was recorded for 3 years from bare and vegetated treatment plots. Sown seeds showed high levels of innate dormancy and only 4% of seeds emerged when sown immediately after collection. Longer storage of seeds after collection resulted in more seedlings emerging. Estimates of persistent seed banks ranged from 1650 to about 21260 seeds/m2. Most seedlings emerged in spring or autumn and this was correlated with rainfall but not with ambient temperatures. Rates of seed bank decline in both bare and vegetated treatment plots was estimated by fitting exponential decay curves to seed bank estimates. Assuming no further seed inputs, it was estimated that it would take about 3 and 5 years, respectively, for seed banks to decline to 150 seeds/m2 in bare and vegetated treatments.

Current Land Use in the Poplar Box (Eucalyptus Populnea) Lands.

1980 ◽  
Vol 2 (1) ◽  
pp. 31 ◽  
Author(s):  
EJ Weston ◽  
DF Thompson ◽  
BJ Scott
Keyword(s):  
Land Use ◽  
Native Species ◽  
Crop Production ◽  
New South ◽  
New South Wales ◽  
High Water ◽  
Grazing Pressure ◽  
Small Areas ◽  
South Wales ◽  
Domestic Livestock

Poplar box (Eucalyptus populnee) woodlands mainly occuron duplex, clay and red earth soils between the 300 mm and 750 mm rainfall isohyets. The poplar box lands have been occupied for from 100 to 150 years and have been modified extensively through tree felling, ringbarking, clearing, cultivation, burning and grazing by domestic livestock. The current land use is described for six vegetation groups which together comprise the poplar box lands. The eastern areas of the poplar box lands are mainly used for intensive agriculture based on wheat. barley and grain sorghum, with small areas sown to c~ops of high water demand. Mixed farming involves dairying (in Queensland) and fat lambs (in New South Wales) and broad-acre cereal and fodder cropping. Sheep and cattle grazing replace intensive crop production as the rainfall decreases. In all areas used for cropping the stability and fertility of the soil are of paramount importance in maintainihg production. The use of woodlands in areas of lower rainfall can lead to deterioration of the resource and to the encroachment of woody native species into the grazing lands. Because cropping is unreliable the opportunity to use cultivation to control woody regrowth is reduced. In central areas much of the land can be sown to improved pastures, but in western areas diversification is limited by the low rainfall and land use is restricted to grazing, initially only by sheep but now by sheep and cattle. Particularly in western New South Wales the increase in unpalatable shrubs and the decrease in available forage has resulted in low stocking rates, and high grazing pressure, making reclamation and pasture improvement difficult. In consequence many enterprises are becoming uneconomic.

Estimation of evapotranspiration from rice in southern New South Wales: a review

1994 ◽  
Vol 34 (7) ◽  
pp. 1069 ◽  
Author(s):  
E Humphreys ◽  
WS Meyer ◽  
SA Prathapar ◽  
DJ Smith
Keyword(s):  
Water Use ◽  
New South ◽  
Meteorological Data ◽  
Strong Dependence ◽  
New South Wales ◽  
Radiant Energy ◽  
Field Measurements ◽  
High Water ◽  
Management Plan ◽  
South Wales

This paper reviews field measurements of evapotranspiration from rice (ET rice) in the Murrumbidgee Valley of southern New South Wales. The results are compared with US Class A open pan evaporation (E pan) at CSIRO Griffith, and with reference evapotranspiration (ETo) calculated using a locally calibrated Penman equation. Both methods (+ETrice = +Epan or +ETrice = +ETo) give good estimates of total evapotranspiration from flooded rice over the ponded season of about 5 months, from October to February. Variation between seasons in total ETo, rainfall, and ETo minus rainfall is large. Over 32 years, total seasonal ETo varied by a factor of 1.5, while rainfall varied >10-fold. The irrigation water requirement for rice +(ETo - rainfall) varied from 685 mm in 1992-93 to 1350 mm in 1990-91. This large variation highlights the need to adjust the rice water use limit (16 ML/ha or 1600 mm) on a seasonal basis, to detect and eliminate high water use paddocks where percolation to the groundwater or surface runoff is excessive (>2 ML/ha). On average, an irrigation requirement of 10.5 ML/ha is needed to replace net evaporative loss +(ETo - rainfall) for rice flooded for 5 months, October-February. Monthly totals of ETo are compared for several locations within the rice-growing areas of southern New South Wales, and differences between locations are found to be small and not significant. This reflects the strong dependence of evaporation on radiant energy, which is unlikely to vary spatially to a significant extent across the region. ETo calculated from meteorological data collected at CSIRO Griffith therefore provides a definitive basis for estimating evapotranspiration from rice in southern New South Wales. Furthermore, CSIRO Griffith has a computerised meteorological data base going back to the 1930s. Current meteorological data and historical records are readily available by contacting the Metdata Manager. Therefore, the case is made for using CSIRO Griffith ETo as the reference for estimating evapotranspiration from rice in southern New South Wales. This study provides farmers, Land and Water Management Plan groups, and policy makers with a tool that can be used, on a yearly basis, to evaluate rice paddock water use efficiency. It should be adopted to confine rice growing to the least permeable soils.

The Ecology and Distribution of Intertidal Organisms on the Rocky Shores of the Queensland Mainland

1956 ◽  
Vol 7 (1) ◽  
pp. 88
Author(s):  
R Endean ◽  
R Kenny ◽  
W Stephenson
Keyword(s):  
Environmental Factors ◽  
Environmental Changes ◽  
New South ◽  
New South Wales ◽  
High Water ◽  
Rate Of Change ◽  
Tropical Species ◽  
Rocky Shores ◽  
The North ◽  
South Wales

This paper records investigations made on the ecology and biogeography of organisms found on rocky shores in eastern Queensland. Traverses were made at selected localities along a region of the coast bounded by the New South Wales-Queensland border (lat. 28� 15' S.) to the south and Whitecliffs (lat. 16� 39' S.) to the north. An account of general physiographic features and environmental factors in this region is given. It was found that the majority of typical Peronian organisms extended as far north as about lat. 25� S. North of lat. 25� S. tropical species occurred and the degree of overlapping of species from the two adjacent faunas was very small. However, the Moreton Bay-Caloundra region offered a refuge for some tropical forms. Zonation patterns on either side of the biogeographical boundary differed. In southern Queensland the zonation picture was similar to that in New South Wales as described by Dakin, Bennett , and Pope (1948); but in northern Queensland an oyster zone dominated the upper half of the intertidal region, whilst in the lower half a barnacle zone replaced the serpulid zone found in southern Queensland and New South Wales. The effects of various environmental factors on zonation on Queensland shores are discussed. It has been found that generalizations made by Evans (1947b) regarding zonation on British shores are only partially applicable to zonation in southern Queensland. Possible reasons for the differences noted are discussed. Also, the rate of change of percentage exposure to the air, which Doty (1946) has shown to be so potent a factor in determining the zonation of organisms at all levels in the intertidal region of the coasts of Oregon and northern California, apparently determines only the upper levels attained by organisms which extend above mean high water neap tide level on southern Queensland shores. Analyses of the effects of varying environmental factors, including gross environmental changes relating to latitude, on faunistic composition have been made. These have given much information on the general ecology of many common Queensland rocky shore species. Moreover, they have thrown much light on the reasons for the existence of a biogeographical boundary near latitude 25� S. In particular they have shown that such factors as the degree of wave action and salinity are possibly of more importance than temperature in determining the position of this boundary.

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