The influence of nutrient enrichment upon mangrove seedling establishment and growth in the Hawkesbury River Estuary, New South Wales, Australia

This paper reports the findings of a five-year study on the growth patterns, production and means of persistence of white clover in a cool temperate environment with summer dominant rainfall, on the Northern Tablelands of New South Wales. White clover essentially persisted as a perennial, but large and rapid declines in plant frequency occurred during late summer if soil moisture levels became depleted. The critical combination of conditions at which plant frequency was adversely affected occurred when available soil moisture levels declined below 35 mm and mean weekly maximum temperatures exceeded 20�C; conditions which often occur in late summer in this environment. During one prolonged period of moisture stress in the second spring and summer period of the study, all plants died. Regeneration was due to germination of seeds and seedling establishment, but plants subsequently persisted as perennials. Relationships were developed to predict the probability of survival of white clover over the range of temperatures and soil moistures recorded in these experiments. Germination occurred to a variable extent each year, but was observed only during winter and spring. Seedling establishment was effective in only one year, which followed the death of white clover in summer, 1980-81. The sward was slow to recover after seedling regeneration owing to low winter temperatures and competition from established temperate perennial grasses in spring. Seedlings contributed little to dry matter production in spring. These results indicate that white clover is unlikely to be of value as an annual in temperate pastures. Strategies aimed at improving white clover in cool temperate environments, either by management or selection/breeding programs, should therefore focus upon improving the ability of white clover to persist as a perennial.

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

Marine and Freshwater Research ◽

10.1071/mf96079 ◽

1997 ◽

Vol 48 (2) ◽

pp. 147 ◽

Cited By ~ 52

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.

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How past sea-level changes can inform future planning: A case study from the Macleay River estuary, New South Wales, Australia

The Holocene ◽

10.1177/0959683614544055 ◽

2014 ◽

Vol 24 (11) ◽

pp. 1591-1601 ◽

Cited By ~ 1

Author(s):

Sarah A McGowan ◽

Robert GV Baker

Keyword(s):

Sea Level Rise ◽

Sea Level ◽

New South ◽

New South Wales ◽

River Estuary ◽

The Past ◽

Case Study Area ◽

South Wales ◽

The Future

Climate change poses many challenges for the future management and development of the coastal zone. Uncertainties in the rate of future sea-level rise reduce our ability to project potential future impacts. This study seeks to further develop the past–present–future methodology proposed in Baker and McGowan and apply it to an additional case study, the Macleay River estuary, New South Wales (NSW), Australia. The past–present–future methodology uses evidence from the past, the Holocene and Pleistocene, to formulate a response function that can be used to project future sea-level heights. Three scenarios for 2100 were developed to emphasise the uncertainties surrounding future sea levels and the need to consider multiple sea-level rise scenarios when planning for the future: a best case (90 cm rise), mid-case (2.6 m rise) and worst case (5 m rise). Light detection and ranging (LiDAR) data were used to project each of the three scenarios onto the case study area of South West Rocks. The methodology was tested by using shell samples extracted from cores which were AMS dated to determine whether or not Holocene estuarine conditions correlated with the proposed future sea-level rise inundation scenarios. We also conducted an audit of potentially affected infrastructure and land uses, and proposed possible future adaptation strategies for the case study area.

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A survey of the regeneration of some problem shrubs and trees after wildfire in western New South Wales.

The Rangeland Journal ◽

10.1071/rj9790363 ◽

1979 ◽

Vol 1 (4) ◽

pp. 363 ◽

Cited By ~ 15

Author(s):

AD Wilson ◽

WE Mulham

Keyword(s):

Seedling Establishment ◽

Tree Species ◽

New South ◽

New South Wales ◽

Common Species ◽

Fire Intensity ◽

Natural Fires ◽

South Wales ◽

Average Survival ◽

Cypress Pine

The regeneration of several shrub and tree species in western New South Wales was recorded after widespread natural fires in the summer of 1974175. At 25 locations, plots were established in the wake of the fires and observations were recorded of the rue damage, the regrowth of the plants and post-fire seedling establishment. Interest was centred on species regarded as woody weeds. Fourteen months after the fires, the average survival of seven of the most common species was: Callitris columellaris (white cypress pine) 275, Acac~a aneura (mulga) 16%, Dodonaea attenuafa (narrow-leaved hopbush) 26%, Cassia eremophila var. platvpoda (punty) 48%, Acacia homalophylla (yarran) 87%, Eremophila mitchell~i (budda) 88% and Eremophila sturtii (turpentine) 87%. These results are for plants whose leaves were totally scorched or burnt. For Dodonaea attenuafa and Cassia eremophila there was a large difference in recovery between locations, a difference which was not explicable in term of fire intensity or shrub size. Post-fue seedling establishment occurred with these two shrubs, particularly with D. attenuata, which had high seedling numbers on eight of the eleven locations.

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Threat and stress in the Clarence River estuary of Northern New South Wales

Human Ecology ◽

10.1007/bf01418730 ◽

1981 ◽

Vol 9 (4) ◽

pp. 419-432 ◽

Cited By ~ 2

Author(s):

J. S. Burgess ◽

Eric Woolmington

Keyword(s):

New South ◽

New South Wales ◽

River Estuary ◽

South Wales

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Reproductive Development and Seedling Establishment of Aristida ramosa R.Br. in Northern New South Wales.

The Rangeland Journal ◽

10.1071/rj9800124 ◽

1980 ◽

Vol 2 (1) ◽

pp. 124 ◽

Cited By ~ 7

Author(s):

AR Harradine ◽

RDB Whalley

Keyword(s):

Seed Production ◽

Seedling Establishment ◽

High Probability ◽

Seedling Recruitment ◽

New South ◽

Management Strategies ◽

New South Wales ◽

Reproductive Development ◽

Pasture Management ◽

South Wales

The reproductive development and seedling recruitment of Aristida rarnosa R.Br. \vas studied under field conditions at six sites on the Northern Tablelands and Northwestern Slopes of New South Wales. A. rarnosu is an undesirable species in pastures because of its low palatability and the propensity of its seeds for causing fleece contamination and mechanical injury to stock. All tillers ofA. vanlosa plants appear to be potentially reproductive and the extensive tiller branching means that each tiller has a high probability of completing the reproductive cycle. Individual plants, therefore, have a high potential for seed production. 'The majority of the seed production occurred in March averaged over all sis sites. Seedlings appeared in each one of the 20 months of observation when the results from all sites were added together, with the majority of seedlings appearing in the spring and autumn. Autumn seedlings had the greatest chance of becoming established at the lower, more western sites while spring seedlings survived best on the Tablelands. The results are discussed with respect to devising pasture management strategies aimed at reducing the abundance of A. wrnosa.

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