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

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.

1997 ◽  
Vol 37 (4) ◽  
pp. 439 ◽  
Author(s):  
T. S. Andrews ◽  
C. E. Jones ◽  
R. D. B. Whalley

Summary. Four experiments were conducted to determine the effects of temperature, light and leaf extract solutions on the germination of Giant Parramatta grass [GPG, Sporobolus indicus (L.) R. Br. var. major (Buse) Baaijens] collected from a population on the North Coast of New South Wales. In the first experiment, seeds were subjected to one of a range of temperature combinations immediately after collection and again after 8 and 27 weeks. Germination was restricted to a narrow range of alternating temperatures with a peak at 35°C day/15°C night when seeds were tested immediately after collection. More seeds germinated when the samples had been stored, although germination remained depressed at constant temperatures. These data indicate that freshly collected GPG seeds are subject to primary dormancy and that few would germinate in the field immediately after seed fall. In a second experiment, seeds were buried beneath leaf litter in a pasture immediately after collection. After 7 months, the seeds were exhumed and subjected to either constant (20°C) or alternating (35/15°C) temperatures in either full light, reduced red:far-red (R : FR) light or dark treatments. Over 95% of GPG seeds germinated when subjected to alternating temperatures, regardless of light treatment. At constant temperatures, 97% of seeds germinated under full light, 59% at reduced R : FR light and <1% in dark treatments. A germination response to alternating temperatures and/or light treatments has been reported in pasture weeds and may be an adaptation to detecting gaps in the pasture canopy. Consequently, the germination of GPG in a pasture may be manipulated to some extent by altering the amount of pasture cover using grazing management, mowing and fertiliser applications. In experiment 3, leaves from a range of coastal grasses were mixed with water and the solutions were used to germinate GPG seeds. Solutions extracted from setaria (Setaria sphacelata) leaves completely inhibited GPG germination while 27% of GPG seeds germinated when imbibed with kikuyu leaf extract solution. Solution extracted from carpet grass (Axonopus affinis) leaves had the least effect on GPG germination. In experiment 4, the effects of solutions that had been leached from the leaves of either setaria or carpet grass on seed germination, and root and shoot lengths of GPG seedlings were compared. Germination was less inhibited by leachate solutions compared with the extract solutions used in experiment 3. Seedlings in setaria leachates had significantly shorter roots and shoots than both those germinated in carpet grass leachates and control seedlings. This may explain, at least in part, why carpet-grass-based pastures are readily infested with GPG while setaria-based pastures are relatively resistant to infestation. The potential for allelopathic interactions between GPG and setaria to be fully utilised to reduce the abundance of GPG in coastal New South Wales pastures is discussed.


2020 ◽  
Vol 26 (1) ◽  
pp. 45 ◽  
Author(s):  
Laura White ◽  
Claudia Catterall ◽  
Kathryn Taffs

Ecological information about threatened species is required to guide strategic management approaches for effective biodiversity conservation in Australia. Arthraxon hispidus (hairy jointgrass) is a listed threatened species in New South Wales (NSW), but there is limited information on its habitat preferences and native vegetation associations, as well as the impact of historical and ongoing anthropogenic disturbance on its distribution and abundance. In the present study, populations of A. hispidus on the north coast of NSW were surveyed to investigate the habitat characteristics associated with various occurrences of the species. Its preferred habitat was found to be dense ground-cover formations in high-moisture, low-canopy conditions. Cover was highest in moisture-associated assemblages in and around wetlands, drainage lines and groundwater seepages, often in association with native grasses, sedges and herbs. These findings suggest that naturally open freshwater wetland communities comprise the most plausible native habitat niches for A. hispidus populations on the north coast of NSW. A. hispidus also occurs widely among introduced pastures and weeds in previously forested areas, demonstrating the species’ potential to exploit derived habitat. Results indicate that, although ongoing disturbance continues to promote A. hispidus in these exotic-dominated landscapes where historical clearing has created potential habitat opportunities, anthropogenic disturbance (slashing or cattle grazing) is not necessary to sustain A. hispidus within native-dominated wetland communities. Findings suggest more scope for integrated management of A. hispidus within broader native vegetation conservation strategies rather than a single species approach.


Oceania ◽  
1957 ◽  
Vol 27 (3) ◽  
pp. 190-209 ◽  
Author(s):  
Malcolm J. C. Calley

1997 ◽  
Vol 166 (6) ◽  
pp. 290-293 ◽  
Author(s):  
Tim J Sladden ◽  
Alan R Hickey ◽  
Thérèse M Dunn ◽  
John R Beard

1971 ◽  
Vol 11 (50) ◽  
pp. 307 ◽  
Author(s):  
GJ Murtagh

The effectiveness of chemical seedbed preparation for sod-sown oats was studied using varying intervals between spraying and sowing. Four herbicides were compared in a second experiment. Both experiments were conducted on paspalum (Paspalum dilatatum) dominant pastures on red basaltic soil on the North Coast of New South Wales. Herbicides were most effective when applied at 6.7 kg acid equivalent a hectare. At this rate, the highest yields of dry matter and nitrogen were obtained when there was a three-week interval and considerably less when there was no interval. A mixture of 2,2-DPA (2,2-dichloropropionic acid) and amitrole (3-amino-1,2,4-triazole) was more effective than 2,2-DPA alone with a three-week spraying interval but there was no difference with a six-week interval. Both amitrole and a mixture of amitrole and ammonium thiocyanate were ineffective for chemical seedbed preparation on paspalum pastures;


Zootaxa ◽  
2012 ◽  
Vol 3575 (1) ◽  
pp. 1 ◽  
Author(s):  
J. K. LOWRY

The sand-hopper Bellorchestia mariae sp. nov. is described from Honeymoon Bay on the north coast of Jervis Bay, NewSouth Wales, Australia. It is the sister species of B. richardsoni Serejo & Lowry, 2008 and appears to have a limited dis-tribution from about Narrawallee in the south to northern Jervis Bay. The distribution of B. richardsoni Serejo & Lowry,2008 is extended from Point Ricardo, Victoria, northwards to Ulladulla on the New South Wales coast. A new synonymyis proposed for the sand-hopper Notorchestia quadrimana (Dana, 1852) which includes N. novaehollandiae (1899) andN. lobata Serejo & Lowry, 2008. It is considered to be a wide-ranging species from Shark Bay in Western Australia aroundthe south coast to at least Maitland Bay in central New South Wales. The beach-hopper Orchestia dispar Dana, 1852 isdescribed from Valla Beach in northern New South Wales and moved to the new genus Vallorchestia. This is the first re-cord of V. dispar since its original description 160 years ago. The beach-hopper Platorchestia smithi sp. nov. is describedfrom Brooms Head, New South Wales, Australia. It is common on ocean beaches from Bendalong in the south to Ballina in northern New South Wales. South of Bendalong beach-hoppers on ocean beaches appear to be absent.


1980 ◽  
Vol 20 (102) ◽  
pp. 25
Author(s):  
RDH Cohen

Lamb production was studied in an experiment that ran for four years, 1968 to 1972, at Grafton, New South Wales, in a region where no commercial sheep are grown. Merino and Dorset Horn x Merino ewes stocked at 15 ewes ha-1 were mated in spring to Border Leicester rams and the lambs sold for slaughter in October. The mean number of lambs born per 100 ewes mated was 81.7 for crossbred ewes and 48.4 for Merino ewes (P< 0.05) and the mean carcase weights of the lambs were 14.8 kg and 12.7 kg, respectively (P< 0.01). The mean weight of fleeces cut from Merino ewes (3.24 kg) was greater (P< 0.01) than that from crossbred ewes (2.58 kg). The ewes were treated with anthelmintics either every four weeks or according to climatic conditions. There were no significant differences between the anthelmintic treatments for lamb liveweights at birth, weaning or slaughter; carcase weight; ewe fleece weight; or mortality rate. Treatment every four weeks increased ewe live weight during only one short period from August 1971 to February 1972 (P< 0.05). Data from this experiment compared favourably with survey data for the high rainfall zone in Australia and it was concluded that prime lamb production on the north coast of New South Wales is biologically feasible.


1998 ◽  
Vol 25 (3) ◽  
pp. 243 ◽  
Author(s):  
D. J. Sharpe ◽  
R. L. Goldingay

The diet of the squirrel glider (Petaurus norfolcensis) was described by qualitative observations of feeding behaviour at a floristically rich site on the north coast of New South Wales. Twelve gliders from six groups were examined over a 10-month period. Flowering and bark-shedding data were also collected. Nectar and pollen were the most important food resources and accounted for 59% of all observations. Banksia integrifolia was the most important source of these foods, but eucalypts were used heavily when in flower and several other genera were also visited. Feeding on arthropods constituted 26% of all feeding observations. Arthropods were harvested in all months of the study from a variety of substrates. Feeding on arthropods was relatively unimportant in May and June when pollen ingestion was presumed to be high. Honeydew was used but was absent from the diet during winter. Acacia gum was obtained from two species in autumn and one, Acacia irrorata, was incised to promote gum production. Corymbia intermedia and Angophora woodsiana were incised for sap in autumn and winter. Sap flows resulting from insect (borer) damage on other species were also used. Fruit, Acacia seeds and arils, and lichens were consumed on a few occasions. The squirrel glider displayed seasonal trends in feeding behaviour that, in part, accorded with observed phenological patterns. The foods used by the squirrel glider during this study were similar to those previously reported for the genus. However, few studies have documented such a diversity of dietary items at one site. Management of the squirrel glider appears to require the maintenance of floristic diversity, and particularly the persistence of midstorey species.


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