Migration,well-being and development in coastal New South Wales 1976-91

"The study seeks first to ascertain whether the age profile of net migration [in coastal New South Wales, Australia] varied during the period 1976-91.... The second aim is to determine whether or not the impact of net migration on population growth remained constant throughout the period 1976-91. Thirdly, the study seeks to ascertain whether or not socio-economic change during the period can be shown to be indicative of areal variations in advantage and disadvantage. Fourthly, it seeks to determine whether there is any association between age-specific net migration and family composition and, if so, to determine whether this association may be indicative of areal variation in development. Fifthly, classifications of the socio-economic characteristics of the population are undertaken...."     

Farmer-driven Innovation in New South Wales,Australia

Knowledge generation and the interactions that allow for knowledge exchange are key processes of innovation. Yet these processes are not well understood at the farm level, nor are they well reflected in policy approaches for agricultural innovation. Farmers in New South Wales have used diverse ways to implement innovations in land management. They employ a range of strategies including observing signals from the landscape, independent testing and trialling, use of agronomists, participation in farmer groups and in farmer-driven research programmes. Steps to foster farmer-driven innovations and knowledge-intensive agricultural systems require greater subtlety to enable flexibility, the incorporation of contemporary scientific knowledge and support for sustainable initiatives. More research on innovation and on policy engagement is required to foster on-farm innovative capacity.     

Late Holocene Fluvial Change in a Tufa-depositing Stream: Davys Creek,New South Wales,Australia

Tufas are constructional landforms composed of calcium carbonate. They are common in karst terrains, and are known worldwide as useful archives of palaeoenvironmental information. In the case of fluvial tufas, these carbonate deposits experience net aggradation when environmental conditions are stable, whilst incision through the deposits occurs when conditions become wetter. In this study, the first of its type in temperate Australia, we used geomorphological and sedimentological evidence preserved in fossil tufas and alluvial terraces to investigate the fluvial history of Davys Creek (NSW, Australia). The nature and timing of fluvial changes along two quasi-independent reaches of the creek were synchronous, suggesting the operation of externally driven processes rather than local internal fluvial adjustments. Following a period of sustained aggradation, rapid incision occurred along the creek between 1500 and 1600 years before present ( bp ) in response to a shift to a moister climate. This was succeeded by a second major aggradation event (1500 years bp to 150 years bp ), then subsequent incision following the arrival of Europeans at 150 years bp.     

On Squatters,Settlers and Early Surveyors: historical development of country road reserves in southern New South Wales

Country roads are an important social, economic and ecological component of agricultural landscapes in many parts of New South Wales. Using the Lockhart Shire Council area as a case study, this paper describes how present-day rural road networks are a historical vestige of past land-use decisions; a collection of Travelling Stock Routes, pastoral boundaries of early squatters, rail reserves, county and parish boundaries, and an ad hoc collection of mostly 1 chain (20.12 m) roads surveyed during the late 1800s. Road reserves were allocated across the landscape at the discretion of early surveyors, so new land titles could access vital water resources. Nineteenth-century surveyors faced many difficulties in surveying the extent of NSW, sometimes resulting in misalignments which today give ‘character’ to many country roads. Road reserves were often surveyed 2 or 3 chains wide to allow for predicted usage and provide materials for road construction. In the 1870s, Travelling Stock Routes of varying widths from 1 to 80 chains wide (one mile) were gazetted, which often form an integral part of many country road networks. In this way, present-day conservation values of many road reserves is a direct legacy of land policies, administrators and surveyors on the landscape today.     

Cainozoic heritage in the modern landscape near Bungonia,southern New South Wales

The regional topography of much of the New South Wales Southern Highlands was long attributed to Quaternary erosion, but it has been recently demonstrated that the region was, in fact, well developed by the Eocene. The hillsides at Inverary Park are mantled by the Late‐Eocene Reevesdale Basalt, thus indicating the extent of landscape development by the mid‐Tertiary. Pre‐, intra‐, and post‐basaltic alluvial and lacustrine sediments are compared with the current extent of the basalt, clearly demonstrating the age of this landscape and the paucity of modification since the Late Eocene. Stratigraphic techniques, U/Th, TL and ¹⁴C dating aid reconstruction of much of the Cainozoic history of Inverary Park. Major changes in sediment type and source have long been common, but Late Quaternary changes do not correlate well with similar observations elsewhere, suggesting that changes in hydrologic regime, notably climate change, are not necessarily responsible for changes in the stratigraphic record. This landscape development and preservation is also at odds with most models of landscape development.     

Land Use and Lake Sedimentation on the New England Tablelands of New South Wales,Australia

Lead-210 methods have been used to establish a chronology of sedimentation extending back almost 80 years in Black Mountain Lagoon near Guyra on the New England Tablelands of north-eastern New South Wales, Australia. Estimates of the direct atmospheric fallout of unsupported ²¹⁰Pb and historical records of the pattern of phosphorus input to the lake provide support for the ²¹⁰Pb chronology. The sediments in the lake record an episode of disturbance which took place prior to c .1916, but after c .1790-1860. Since then, however, the site-specific rate of minerogenic sedimentation has been maintained at a relatively low and constant level of 0.93 kg m^-2 a^-1. [Note: the following symbols are used in this paper: a = year (annum), and d min^-1 g^-1 = radioactivity (spontaneous nuclear disintegrations per minute per gram of material).] This is despite major shifts in land use and intensification of agriculture, despite the occurrence of significant floods and droughts, and in the absence until recent times of the application of soil conservation practices. These rates may be contrasted with rates of 0.023 kg m^-2 a^-1 from the period 12.3-5.6 ka. These are at least an order of magnitude lower than those of the twentieth century. The lake sediments preserve evidence of the use of agricultural chemicals on the catchment during the twentieth century. These include phosphorus, zinc, arsenic and lead. Soils and sediments may act as long-term toxic stores for such chemicals, a problem often overlooked in rural areas.     

The distribution of airborne metals in the Illawarra region of New South Wales, Australia

The moss bag technique of air quality monitoring has been used to assess the spatial and temporal distribution of iron, manganese, lead, zinc, copper and cadmium in the vicinity of the Port Kembla industrial complex. Data for September and December 1980, and April 1981 are presented as representative of spring, summer and autumn climatic conditions. The results showed that the concentration of all elements fell off markedly with distance from the pollution source, with cadmium and copper being restricted to the immediate vicinity of the smelter. Some change in the seasonal pattern is evident and appears to be largely controlled by wind conditions at the source.     

Informing Program Design for Connectivity Conservation in the New South Wales Southern Highlands,Australia

Connectivity initiatives typically require conservation action on private lands as a complement to public reserve systems, so they are more likely to succeed if underpinned by knowledge of the social factors influencing landholders' participation. Using a combination of social survey and market research techniques, we identify spatially referenced landholder segments. Using a number of behavioral and attitudinal constructs, including three psychographic constructs not previously used for identifying segments—sense of place, lifestyle motives, and nature values—we identify three lifestyler and two farmer segments, and show that the characteristics of lifestyler segments are more nuanced than previously thought. Preferences for four corridor connectivity initiatives are found to differ across landholder segments, which indicates the importance using a targeted approach for designing connectivity conservation programs. The results highlight the importance for achieving corridor connectivity of the Blue Collar Lifestyler segment, a lower sociodemographic segment not previously identified in the literature.     

A Holocene paleoenvironmental history of Lake Alexandria,South Australia

An investigation of Holocene sediments within Lake Alexandrina, a shallow coastal lake at the mouth of the Murray River, South Australia, is presented based on a multidisciplinary approach.¹⁴C and²¹⁰Pb radiometric dating methods are used to establish a geochronological framework for the last 7000 yr BP, and diatoms, sand-siltclay ratios, organic carbon, phosphorus and copper concentrations are used to infer paleoenvironmental changes.The diatom assemblages indicate a change from marine-brackish to oligosaline-freshwater conditions between 7000 and 6000 yr BP, with sea-level stabilisation and continuous barrier formation across the Murray mouth. Sand pulses after 2300 yr BP document sand spit formation in the lake and the commencement of extensive lacustrine sedimentation.In the past 100 years which include the advent of European settlement in the region, the short-term²¹⁰Pb-based mass accumulation rate of 0.063 g cm^–2 yr^–1 is greater than that of the longer-term mean¹⁴C-based rate (0.023 g cm^–2 yr^–1), and high concentrations of phosphorus and copper correspond to historical records of blue-green algal blooms.This is the fifth in a series of papers published in this issue on the paleolimnology of aric regions. These papers were presented at the Sixth International Paleolimnology Symposium held 19–21 April, 1993 at the Australian National University, Canberra, Australia. Dr A. R. Chivas served as guest editor for these papers.     

Late Pleistocene to early Holocene aeolian activity in the upper and middle Shoalhaven catchment,New South Wales

Thermoluminescence dating of relict source‐bordering dunes in the middle and upper Shoalhaven catchment show them to have been active between 19ka and 6ka. During this time, except for a brief period of dune stability sometime between 18 ka and 14ka, the climate of this area was considerably drier than present. The onset of aeolian activity here coincides with the glacial maximum indicating that it was not until then that arid or semi‐arid conditions were able to penetrate the humid coastal rim of south‐east Australia. The extension of these conditions into the early Holocene, whilst supported by the palaeobotanical record of nearby Lake George, contrasts with pollen evidence from other nearby catchments, suggesting that there were variable environmental responses throughout the south‐east highlands of NSW to the amelioration in climate during the early Holocene.     

Paleolimnological evidence of Holocene climatic changes in Lake Blanca, southern Uruguay

Paleolimnological data are presented on Holocene climatic changes in Lake Blanca, a small (0.6 km²), coastal fresh waterbody in southern Uruguay. Using a sediment core that extended to 7,300 year BP, analyses of pooid, panicoid and chloridoid phytoliths (Poaceae) allowed us to identify 16 Opal Phytoliths Association Zones (OPAZ). Both temperature and humidity indices were calculated from relative percentages of opal phytoliths and the climatic trends were inferred. During the early Holocene, prior to the first Holocene marine transgression (∼ ∼8,000–7,000 yr BP), cool-arid climatic conditions were inferred. After the first Holocene transgression, predominance of cool-humid conditions was registered until about 4,000 yr BP. A transition from cool-semiarid/arid to alternate warm-temperate and humid-very-humid conditions was detected for ∼∼4,000–1,000 yr BP. Increases in trophic state were observed because of such a climatic amelioration. After ∼ ∼1,000 yr BP, a shift from warm to temperate and cool temperatures was inferred. Such a cooling episode was assigned to a “LIA” which took place by the end of the 18th century and the beginning of the 19th century. A decrease in trophic state was observed during this climatic deterioration. After such a little ice age, present temperate humid conditions were established. The humidity indices calculated from relative percentages of opal phytoliths for the last ∼ ∼70 years were compared to annual rainfall data. Such a comparison showed that opal phytoliths are reliable indicators of humidity.     

A fluvial sediment budget for upper Wolumla Creek,south coast,New South Wales,Australia

Extensive valley fills have formed at the base of the escarpment in granitic catchments along the south coast of NSW. On the 1865 portion plan, the valley fill surface in the upper part of Wolumla Creek, in the Bega River catchment, was intact, but within a few decades of European settlement of the area the valley fill had been incised. Today the incised channel is up to 10 m deep and 100 m wide. The catchment drains an area of just 18.2 km². Based on detailed field mapping, with extensive drilling and angering, the volume of the intact valley fill in upper Wolumla Creek in 1865 was approximately 5000 × 10³ m³. Between 1865 and the present day, approximately 3500 × 10³ m³ of this material has been removed, leaving roughly 1500× 10³ m³ of material stored on the valley margins. During an initial period of discontinuous gullying, approximately 230 × 10³ m³ of sand accumulated as a floodout. Subsequently, the incised channel became continuous, cutting through the floodout; over 50 per cent of floodout deposits were removed. Flushing of the materials released from upland valley fills has been very efficient in the Wolumla Creek catchment, with a sediment delivery ratio of around 70 per cent. The efficient downstream transfer of deposits reflects bedrock confinement in downstream reaches. Extensive volumes of material have accumulated along the lower reaches of the catchment, exacerbating the transformation to the geomorphic character of the lower Bega River.     

Thermoluminescenge and Uranium‐Thorium chronologies of pleistocene coastal landforms of the Illawarra region,New South Wales

TL determinations of the ages of aeolian sands and U/Th determinations of the ages of crusts on rock platforms in the Illawarra region, especially at Red Point, indicate that these techniques give considerable promise of a major advance in deciphering the Pleistocene coastal record in Australia. The methods of dating are outlined, and problems of laboratory and field interpretation are considered. The longstanding debate as to whether the +2 m level of platforms is modern or is a Pleistocene relict has been resolved for the Illawarra coast, where these platforms can be shown to have been formed during the Last Interglacial high stand of the sea. By inference, the +4 m level must be of at least the same age. The +6 to 7 m level was cut by about 300Ka and may be as old as Pliocene. Four aeolian units at Red Point reworked from nearby barrier beach complexes date from c. 25Ka, 45Ka, 125Ka, and 300 to >400Ka. Reconnaissance surveys and dating indicate that aeolian sands of similar ages occur elsewhere along the New South Wales coast.     

Energy Policy in Australia: A comparison of environmental considerations in New South Wales and Victoria

World-wide, people and governments are gradually becoming more aware of the potential environmental, economic and health effects of climate change and the need for governments to take action to mitigate such impacts. This was emphasised by the creation of the United Nations Framework Convention on Climate Change (UNFCCC), signed at the Rio Earth Summit in 1992. There has been much discussion on the greenhouse policy response of the commonwealth government of Australia, especially its stance taken at Kyoto in December 1997. Despite the recent nationalisation of Australia's state energy markets, due to Australia's federal political structure, much of the policy responsibility for energy and environmental issues rests with the states. Given these circumstances it is surprising that there has been relatively little academic focus on the energy policies of the states. This paper attempts to partially fill the policy analysis 'gap' by investigating the present environmental aspects of the energy policies of NSW and Victoria, implemented since the signing of the UNFCCC in 1992. NSW and Victoria are Australia's most populous states and are responsible for the bulk of the nation's greenhouse gas emissions with two very distinct policies.     

Unexpected post-settlement freshening and increase in charophytes in Bombah Broadwater (Myall Lakes,New South Wales,Australia)

Bombah Broadwater is a shallow coastal lake within the Ramsar-listed Myall Lakes system on the mid-north coast of New South Wales, Australia. Increased nutrient and sediment loads resulting from catchment modification are thought to have instigated the loss of aquatic plants in the lake, causing it to “switch” from a clear, macrophyte dominated system (similar to the conditions in present day Myall Lake) to a turbid, phytoplankton dominated system. To assess this hypothesis, charophytes, foraminifera and aquatic fauna remains from an 800 year sediment record were examined. The sediment chronology was established using ¹⁴C, ²¹⁰Pb and ¹³⁷Cs radiometric dating and sediment composition. Interestingly, a clear increase in charophytes since European arrival conflicted with the hypothesised aquatic plant loss. Hence, it appears Bombah Broadwater has not undergone a change in stable state since European arrival. An additional and unexpected finding in the patterns of the foraminifera and testate amoeba suggest that Bombah Broadwater has freshened substantially since European arrival. This freshening may have resulted from increased catchment run off as a result of the clearance of catchment vegetation. Since catchment vegetation clearance is widespread in Australia, this finding raises the possibility that post-settlement freshening of coastal lakes may be a common occurrence.     

Catchment-scale (dis)connectivity in sediment flux in the upper Hunter catchment, New South Wales, Australia

(Dis)connectivity within and between landscape compartments affects the extent and rate of transfer of energy and matter through catchments. Various landforms may impede sediment conveyance in a river system, whether laterally to the channel (termed buffers) or longitudinally along the channel itself (termed barriers). A generic approach to analysis of landscape (dis)connectivity using slope threshold analysis in GIS, tied to air photograph interpretation and field mapping of buffers and barriers, is tested in the upper Hunter catchment, Australia. Under simulated conditions, effective catchment area, which is a measure of the proportion of a catchment that has the potential to contribute sediment to the channel network, varies from 73% to just 3% of the total catchment area for differing subcatchments in the upper Hunter. This variability can be explained by the spatial distribution and assemblage of buffers and barriers in each subcatchment. Multiple forms of disconnectivity are evident in some subcatchments, such that when one buffer or barrier is breached, other features still impede sediment transfer within the system. The importance of the position of buffers and barriers within any given subcatchment is emphasised. Spatial variability in valley width exerts a critical control on catchment connectivity, with more efficient sediment conveyance in narrow valleys relative to wider valleys characterised by piedmonts, terraces, fans and extensive floodplains in which conveyance is impeded. This variability reflects the landscape history and geological setting of each subcatchment. The framework developed in this paper can be used to assess the impact of natural or human-induced buffers and barriers on catchment-scale sediment flux in any landscape setting, providing a physical template atop which other biogeochemical fluxes could be examined.     

Palaeoenyironments and human impact at Burraga Swamp in Montane rainforest,Barrington tops National Park,New South Wales,Australia

Palaeoecological studies have identified the broad patterns of environmental and climate change in highland south‐eastern Australia, but the detail of human impact on a variety of parameters and their interlinkages is largely missing. This study compares the erosion, productivity, fire and vegetation history in prehistoric and historical times at Burraga Swamp in montane rainforest in New South Wales. The known human impact is meagre; the major presently sustained impacts involve forestry in the surrounding sclerophyll forests and a low level of visits to the swamp by day‐walkers. While no significant changes in the largely oligotrophic conditions or in fire frequency were detected, changes in erosion rates and some vegetation change can be attributed to impacts since European settlement. There has been a small decline in eucalypts and a loss of fern cover, while grasses, Urtica and exotic species have expanded. It is clear that upland sites are sensitive to environmental change including low‐level human impact.