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The distribution and zonation of intertidal organisms of rocky coasts in south eastern AustraliaKing, Robert John Unknown Date (has links) (PDF)
The intertidal flora and fauna of S.E. Australia (Robe, South Australia to S. New South Wales, including Tasmania) is described in terms of its horizontal and vertical distribution. A detailed account of intertidal zonation, on the central Victorian coast and Bass Strait islands, is included. Environmental features are discussed and sea temperature data for Pt. Lonsdale is presented. / Analysis of the marine flora in S.E. Australia suggests that the concept of separate biogeographic provinces in this region is invalid and the flora is best interpreted as a continuum.
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Tertiary fossil wood in South Eastern AustraliaO'Brien, Jane, n/a January 1999 (has links)
Palaeobotany illuminates past environments by relating the fossilised species to
the existing geological conditions. This has previously been done with fossilised
leaves and spores but not with fossilised wood.
The recovery of a significant quantity of wood from an area of Tertiary sediments
in New South Wales, enabled the used of fossilised wood as a
palaeoenvironmental tool. Tertiary sedimentary deposits of south eastern
Australia are diverse lithologically, occupy distinct areas and are limited in vertical
and horizontal extent. However, samples in museum collections together with
samples from field work and descriptions of fossil wood from previous researchers
enabled an analysis of the fossil wood.
The geological and palaeontological aspects of the fossil wood were considered
for each specimen. Only specimens with precise information concerning location
and description of the sedimentary deposits in which the specimens were found
were investigated. Lithology, sedimentary structures and the relationship with
surrounding geological units were also considered.
The samples were then classified and identified. It was possible to identify fossil
wood to Family level by comparison with existing taxa. In the majority of cases,
identification to species level was not possible due to the lack of detail in the
specimen and because features such as colour cannot be used with fossilised
specimens. With Australian fossilised wood, a systematic nomenclature based on
structure observed within the palaeotaxa, would be more relevant. Comparisons
of cell structures with previous work on palaeoenvironmental indicators was found
to be possible.
Fossil wood has two uses. Firstly, as a local environmental indicator, usually in
conjunction with sedimentological data, assessing the rate and direction of water
flow, types of depositional environments and localised floral assemblages.
Secondly, as an indicator of regional climate. Within any one particular time
period, comparisons between the cellular structures of wood found in different
parts of south eastern Australia show gross changes in cell size, mean growth ring
size and vessel size, which enabled generalisations about climate for each epoch
in the Tertiary.
Palaeoclimatic indicators from the wood concurred with previous climatic
interpretations based on palynology and sedimentology. Cool conditions during
the Palaeocene were clearly indicated by small cells and small growth rings which
gradually increased throughout the remainder of the Tertiary. Several areas e.g.,
Dargo High Plains, where cold conditions existed in isolation could be clearly
distinguished. This corresponds with the gradual northward movement of the
Australian plate with consequent increasing temperatures on the mainland.
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The ecology of meiofauna in a temperate mangrove ecosystem in south-eastern Australia.Gwyther, Janet, mikewood January 2002 (has links)
The meiofauna of a mangrove forest in the River Barwon estuary was studied by means of surveys and field experiments. Distinctive assemblages of meiofauna were described from the sediment and pneumatophores of the ecosystem. Fine resolution of phytal habitats was demonstrated, and particular assemblages of meiofauna were characteristic within habitat provided by dominant epibionts. Distribution of the meiofauna within leaf litter revealed high turnover rates of nematodes, and some factors controlling detrital assemblages were assessed. The vertical profile of sedimentary meiofauna was examined, and changes in abundance were related to the tychopelagic habit of many taxa at high tide. Dispersal within the water column was confirmed by pelagic trapping, and colonisation of mimic pneumatophores was investigated. The amount of algal cover, effects of grazing by gastropods, and rugosity of the colonised surface were shown to influence meiofauna colonisation of mimic pneumatophores. Establishment and persistence of patchy distributions of meiofauna at scales of less than 10 m in an intertidal environment was demonstrated, and it was concluded that this was due to the dynamic nature of assemblages rather than their integrity.
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Floodplains as dynamic mosaics : sediment and nutrient patches in a large lowland riverine landscapeSouthwell, Mark, n/a January 2008 (has links)
Rivers around the world are under increasing pressure from a variety of human activities.
Effective management of riverine landscapes requires an ecosystem approach and one that
recognises the complex interactions between their physical, chemical and biological
components. Perceptions of pattern and process are central to our understanding of riverine
landscapes. Pattern and process operate over multiple scales to produce heterogeneous
mosaics of landscape patches that change over time. Hierarchical patch dynamics provides a
useful approach to unravel pattern and process at multiple scales in riverine landscapes. This
thesis adopts a hierarchical patch dynamics approach to investigate floodplain sediment and
nutrient dynamics within the Barwon-Darling River in South Eastern Australia.
The flow regime of the Barwon-Darling River is highly variable. As a result, it has a complex
channel cross section featuring inset-floodplain surfaces that occur at multiple elevations
within the channel trough. These surfaces formed the focus of this study. The texture of inset- floodplain
surface sediments displays a patchy spatial distribution and one that did not reflect
lateral or longitudinal gradients within this floodplain landscape. Rather a sediment textural
patch mosaic was identified. Nutrient concentrations associated with the surface sediments of
the inset-floodplains were also shown to vary significantly resulting in a nutrient patch
mosaic. This spatial nutrient mosaic was enhanced by factors including the surface elevation
of the floodplain surface.
Sediment and nutrient exchange between the river channel and inset-floodplain surfaces was
measured during several flows in 2001, 2002 and 2005. Pin and sediment trap data showed
that significant quantities of sediment were exchanged between the river channel and
floodplain surfaces during inundation with both cut and fill processes occurring. Patterns in
sediment exchange appear to be related to local sediment supply and seasonal sediment
exhaustion, rather than the top down geomorphic constraints considered. These material
exchanges resulted in a change to the spatial configuration of the sediment textural patch
mosaic. Distinct new sediment textural patches were created following inundation, while
other patches were lost post inundation and other patches changed sediment textural character
to move into pre-existing patches. Thus a truly dynamic sediment textural mosaic exists
within this floodplain landscape.
Nutrient concentrations associated with floodplain sediments also changed over time. While
nutrient concentrations increased after the December 2001 flow event, they generally
decreased after the March 2002 event, highlighting their dynamic nature over time. The
spatial distribution of nutrient concentrations also varied over time, with a 40 percent change
to the nutrient mosaic as a result of the March 2002 flow event. In addition to the influence of
the changing physical template (sediment texture mosaic), nutrient concentrations were
shown to be influenced by rainfall processes on non flooded surfaces, and also a number of
top-down constraints and bottom-up influences operating over multiple spatial scales.
Overall, the inset-floodplains studied in this thesis acted primarily as sediment and nutrient
sinks, and were a source for dissolved nutrients. Nutrient exchange was associated with the
exchange of sediments in this riverine landscape, over both inter-flow and decadal timescales.
It was demonstrated that water resource development within the catchment reduced the
number, magnitude and duration of flow events down the Barwon-Darling River and as a
result reductions in the exchange of sediment, associated and dissolved nutrients between
inset-floodplains and the main river channel were calculated. The greatest reductions were
with the release of dissolved nutrients (42-25 percent) and the exchange of sediment and
associated nutrients from high level surfaces (43 percent).
Effective conservation and management of riverine ecosystems must occur at the correct
scale. This study identified potential nutrient hotspots at several scales in the Barwon-Darling
floodplain landscape that could be targeted by management. The low predictability of the
location of nutrient hotspots at the inset-floodplain scale over time means that environmental
flows should be targeted at high level surfaces (<25 000 MLD-1) that provide long term
sources of carbon to the river channel. Conserving flows of this magnitude will also reinstate
flow variability, an important facet of the Barwon-Darling River?s hydrology that has been
changed by water resource development. The research presented in this thesis highlights the
importance of not only considering pattern and process at multiple scales, but also the way in
which these processes influence landscape patterns over time, leading to the identification of
the appropriate scales that can best be targeted for the conservation of these systems.
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The Influence of fluvial geomorphology on riparian vegetation in upland river valleys: south eastern AustraliaEvans, Lisa J, n/a January 2003 (has links)
Healthy riparian vegetation has a positive impact on the adjacent river. Unfortunately,
riparian vegetation is often threatened by human impacts such as dam construction and
clearing. To gain the knowledge underlying the effects of such impacts and to aid riparian
rehabilitation, the objective of this thesis was: to determine riparian vegetation association
with, and response to, variation in fluvial geomorphology over several scales and
consequently to fluvial disturbance. Only woody riparian plant species were considered.
Flood disturbance was the unifying theme of this thesis. Linked to this theme and arising
from the main objective was the supposition that plant interactions with the abiotic
environment, but not biotic interactions between species, control riparian species distribution
because of frequent fluvial disturbances.
Woody riparian vegetation and riverine environmental variables were recorded along the
upper Murrumbidgee River at three spatial scales based on a geomorphic hierarchy for
Chapter 2. Multivariate analysis was used to group species and to associate environmental
variables with vegetation at the three spatial scales. Observations at the two larger scales, of
river segment (site) and riparian reach (transect), identified a river-longitudinal speciescomposition
gradient associated with geology, river width and stream channel slope.
Observations at the smallest scale of geomorphic units (plot) identified a lateral riparian
gradient and also the longitudinal gradient; these gradients were associated with geomorphic
variation, land use, plot elevation and also river longitudinal variables.
Using the same data set, but varying the spatial scale of analysis caused the species
composition pattern to change between scales. Increase in scale of observation, that is from
geomorphic unit to reach and segment scales, resulted in disproportionate importance of rarer
species and decreased importance of some key riparian species at the larger scales. It would
appear that in this instance the geomorphic unit scale best described patches of different
species composition because this scale had high spatial resolution and was also able to
identify multiple gradients of environmental variation. It was recommended that riparian
sampling take place at scales that represent dominant gradients in the riparian zone. These
gradients are represented by geomorphic scales, indicating the appropriateness of using
geomorphic based scales for observation of riparian vegetation. Chapter 3 considered whether there is a geomorphic template upon which riparian vegetation
is patterned and whether it is associated with process variables, such as flooding and soil type.
This question was investigated at different spatial scales in three ways: i) by an experiment to
determine whether soil nutrient condition affects plant growth; ii) by graphical analysis of
trends between geomorphic units, species and process variables; and iii) by analysis of
vegetation distribution data.
The smallest scale (meso) found experimental differences in plant growth because of soil
type. Plants growing in sand had the lowest performance, with an average plant Relative
Growth Rate (RGR) of 0.01, compared to plants growing in soils with small amounts of silt or
clay particles, with an average plant RGR of 0.04. This pattern was attributed to differences
in nutrients. Clear relationships were demonstrated at the larger geomorphic unit scale
between species distribution and process variables. For example, hydrology and substratum
type were found to be associated with geomorphic units and species. The largest scale
considered in Chapter 3 was the riparian reach scale. At this scale species were clearly
grouped around reach type. Therefore, geomorphology was considered to be a template for
riparian species distribution. Findings in this chapter suggested that geomorphic variables
should be good predictors of riparian species distribution. This hypothesis was tested and
supported in Chapter 6.
The experiments reported in Chapter 4 aimed to determine whether inundation depth and
duration affected plant performance and survival for five common riparian zone species.
Riparian seedling patterns in the field were also compared with experimental results to test
whether species performance was reflected by field distribution. The experiments that were
conducted included an inundation period and depth experiment, and a survival period test
whilst under complete inundation. Biomass and height relative growth rates were determined,
and the results were analysed using factorial Analysis of Variance. Obligate riparian species
(Callistemon sieberi, Casuarina Cunninghamiana, Leptospermum obovatum) were found to
be tolerant of inundation duration and depth, to the point where inundation provided a growth
subsidy. On the other hand, non-obligate riparian species (Acacia dealbata,
Kunzea ericoides) were either just tolerant of inundation or showed a negative growth
response. For instance, C. sieberi demonstrated an average height RGR of 0.04 after
complete inundation and 0.007 when not inundated, while A. dealbata had an average height
RGR of 0.001 after complete inundation and 0.01 when not inundated. These experimental
findings were found to closely reflect both seedling and adult plant distribution in the field
such that inundation tolerant species were found close to the river and intolerant species
further away. Thus, the conclusion was drawn that riparian species establishment and
distribution is affected by inundation and that change to the flood regime could have serious
impacts on riparian zone plant composition.
The other aim of this chapter was to determine whether optimum germination temperatures
were associated with flood or rainfall. Growth chamber germination trials were conducted at
air temperatures of 15�C, 20�C and 25�C to determine the 'best' germination temperature.
These germination patterns at different temperatures were then related to annual variation in
field temperature, flooding period and rainfall. No evidence was found to suggest a
relationship between ideal germination temperature and flood season, rather it was suggested
that germination was patchy through time and may simply reflect recent rainfall.
Investigations that were reported in Chapter 5 aimed to elucidate relationships between
species and flow velocity variables. Two experiments were conducted: i) a flume experiment
to determine the effect of flow velocity on plant growth; and ii) an experiment to observe the
response of plants to damage (imitating flood damage) and inundation. Field observations of
species distribution and flow velocity related variables were also conducted to put the flume
results into a real-world context.
Treatments for the flume experiment were fast flow velocity (0.74 m s-1), slow velocity
(0.22 m s-1) and no velocity (control) but still inundated. All treatments were flooded
completely for four days. Subsequent biomass and height relative growth rates were
determined, and the results were analysed using factorial Analysis of Variance. Results were
unexpected, given that obligate species exposed to the fastest velocity had the highest growth
rate with an average height RGR of 0.046, compared to plants in still water, which grew the
least with an average height RGR of 0.013. It was hypothesised that this response was
because relatively greater carbon dioxide and oxygen levels were available in the moving
water compared to the still water. With regard to shoot damage, the species that were nonobligate
riparian species lost more leaves from velocity treatment than the obligate riparian
species. The cut and flood experiment found growth of the obligate species
(Casuarina cunninghamiana) to be greater after cutting than the non-obligate species.
Flooding was not found to have an effect in the cut and flood experiment, probably because
the period to sampling after flood treatment was longer (4 weeks) than other flooding
experiments (3 weeks).
Field observations were found to support the experimental findings, with a gradient of species
across the riparian zone that reflected potential flood velocities. Therefore, velocity is one of
a suite of riparian hydrological factors that are partially responsible for the gradient of species
across the riparian zone. Potentially the absence of flooding could result in a homogeneous
mix of species, rather than a gradient, except on the very edge of the river.
The study that was reported in Chapter 6 investigated a technique for predicting riparian
vegetation distribution. One of the aims of this investigation was to address a current riparian
rehabilitation shortfall, which was how to objectively select species to plant for rehabilitation.
Field data were collected from three confined river valleys in south-eastern New South Wales.
Using data on plant species occurrence and site and plot measures of soils, hydrology and
climate, an AUSRIVAS-style statistical model, based on cluster and discriminant analysis,
was developed to predict the probability of species occurrence. The prediction accuracy was
85 % when tested with a separate set of plots not used in model construction. Problems were
encountered with the prediction of rarer species, but if the probability of selection was varied
according to the frequency of species occurrence then rarer species would be predicted more
often. Various models were tested for accuracy including three rivers combined at the
geomorphic unit (plot) scale and riparian reach (transect) scale in addition to a Murrumbidgee
River plot scale model. Surprisingly, the predictive accuracy of the all rivers and single river
models were approximately the same. However, the difference between the large scale and
small scale models pointed to the importance of including small scale flood-related
parameters to predict riparian vegetation.
When these riparian predictions were compared to predictive outcomes from a hill slope
model, which was assumed to be affected by fewer disturbances (i.e. flooding), predictive
accuracies were not very different. Overall though, predictive accuracy for riparian
vegetation was high, but not good enough to support the supposition that riparian vegetation is
abiotically controlled because of frequent flood disturbance. Nevertheless, geomorphology
and consequently flood effects are still important for the determination of the riparian
community composition.
Overall, riparian vegetation was found to be closely linked to its environment (evidenced in
Chapters 2, 3, 4, 5) in a predictable manner (Chapter 6). Species pattern relied on flood
disturbance affecting species distribution. Some riparian species were found to be highly tolerant of flooding and gained a growth advantage after flooding (Chapters 4 and 5).
Therefore, flood tolerance was important for the formation of a species gradient across the
riparian zone. These species tolerances and growth requirements reflect riparian geomorphic
pattern (Chapter 3), which was suggested to form a template on which riparian vegetation is
structured.
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Experimental evaluation of fox control and the impact of foxes on lambsGreentree, Carolyn, n/a January 2000 (has links)
Baiting with sodium monofluoroacetate (1080) to protect lambs (Ovis aries)
from red foxes (Vulpes vulpes L.) has become more frequent in NSW and other parts
of Australia during the last 10 years despite the lack of reported evidence evaluating
the effects of fox baiting on lamb survival. NSW Agriculture has developed fox
control recommendations aimed at minimising impact, but these guidelines have not
been tested experimentally. Defining the extent of a pest problem and the
effectiveness of pest control are key components of a strategic approach to vertebrate
pest management as it is the damage of pests that justifies their control.
This thesis describes an experimental evaluation of the recommended practice
of fox control in NSW. The effects of three levels of fox control were tested in the
experiment; no treatment, baiting once a year before lambing (the recommended
practice) and baiting three times a year (thought to be the maximum farmers would
instigate). Each treatment had two replicates. No previous manipulative experiment
using synchronous controls and matched replicates has been undertaken to test the
effects. The study quantifies the level of fox predation on healthy lambs and the level
of predation on lambs that had other causes including illness and mismothering
contributing to this fox predation. It also examines the response of the fox
population, lamb predation and lambing outcomes to different levels of fox control.
The cost effectiveness of fox control is examined in relation to lamb predation and an
investigation of the optimum level of fox control is begun. The experiment also
provides the first chance to consider the examination of multiple response variables
and the scale of field ecology experiments required to recognise a significant response
and avoid a Type II error due to between replicate variability even with tightly
controlled site selection criteria to standardise experimental sites, and with the
synchrony of experimental control and treatment surveys.
The study occurred on five sheep properties near Boorowa (34°28'S,
148°32'E) and Murringo (34°18'S, 148°3 1'E) in south-eastern Australia. The terrain
was undulating to hilly with a maximum elevation of 660 m above sea level. The main
agricultural enterprises in the district are Merino wool, fat lamb and beef cattle
production and winter cereal cropping. The native vegetation of Eucalyptus
woodland has been mostly cleared, though remnant patches occur. Most of the area
is now sown with pasture of Phalaris tuberosa, Lolium spp. and clover Trifolium
spp.. The experimental properties grazed self-replacing Merino flocks, primarily for
wool production, so lamb survival was vital to the economic operation of the farm.
Over 50 selection criteria including lamb survival rates, ewe fertility and bloodline,
sheep management practices, climate and habitat features that affect lamb survival,
past fox control practices and prey species were used to select sites Sites were
representative of most sheep farming properties in the region, but were also extremely
similar in factors that affected fox abundance and ewe and lamb survival, thus
minimising variation between replicate sites.
The manufactured meat baits used to poison foxes contained 3 mg of sodium monofluoroacetate (compound 1080). A replacement baiting program was carried
out in 1995 and 1996. Fox control programs were carried out over the experimental
units and adjacent buffer zones covering approximately two fox territories,
approximately 6km2, around the lambing paddock under study. The recommended fox
control practices described by NSW Agriculture also included neighbouring farmers
taking part in an extended group baiting program. In all the area baited at varying
intensities totalled 3400 km2. Synchronised lambing with neighbours was a further
recommended practice to reduce fox predation and was carried out on these sites.
Lambing occurred during a six to eight week period in late winter on all sites, a
practice known as 'spring lambing', and on many surrounding properties so a surplus
of lambs was available to foxes over a relatively short time.
The benefits of fox control were measured directly as enhanced lamb survival
derived from differences in lamb marking rates between ultrasounded flocks of
approximately 1000 ewes and the predation of lambs was measured from over 2000
lamb carcases post-mortemed in 1994, 1995 and 1996. A mean of 138 lambs were
expected at ultrasounding from 100 ewes and 113 lambs per 100 ewes were alive at
lamb marking.
There was no significant (P>0.05) effect of fox control on lambing
performance (the number of lambs per 100 ewes that lambed) Fox predation was
inferred as the cause of lamb death in a minimum of 0.8% and a maximum of 5.3% of
lamb carcases during 1995 and 1996. There was a significant (P<0 05) effect of fox
control on the minimum possible percentage of lamb carcases classified as healthy
lambs killed by foxes, with the percentage declining from 1.50% (no fox control), to
0.90% (fox control once per year) to 0.25% (fox control three times per year). There
was also a significant (P<0.005) effect of fox control on the maximum possible
percentage of lamb carcases classified as healthy lambs killed by foxes with the
percentage declining from 10.25% (no fox control), to 6.50% (fox control once per
year) to 3.75% (fox control three times per year). The observed results were used to
estimate the number of treatment replicates needed to be confident of detecting an
effect of predator control on lamb marking performance. The estimated numbers
were very high if small effects were to be detected. No significant correlation
between the fox density and the minimum and maximum possible number of lambs
carcases classified as killed by foxes was found. Bait uptake was monitored as were
the costs of fox control.
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Prevalence and distribution of Alternaria allergens in rural New South Wales, AustraliaMitakakis, Teresa Zinovia January 2001 (has links)
In rural inland, south-eastern Australia, allergy to the fungus Alternaria is prevalent and an important risk factor for asthma. The aim of the thesis was to investigate the distribution and factors influencing allergens of Alternaria in the air. As airborne allergenic spores were thought to arise from harvesting of nearby crops, two towns with different agricultural practices were studied. Moree has two crop harvesting periods in summer and autumn whilst Wagga Wagga has one harvesting period in summer. Over two years, air was sampled daily in Wagga Wagga and Moree using Burkard traps. The reliability of measurements from a single site to represent the distribution of airborne concentrations of spores across each town was examined using data from three traps simultaneously, sited 2.0 to 4.9 km apart, over four weeks. Substantial intra-class correlation coefficients (ICC) were observed between the three sampling sites across both towns (ICC=0.52, 95% CI 0.30-0.71 to 0.76, 95% CI 0.61-0.87) when counts of Alternaria spores were relatively high. The correlation was poor when counts were low. Of more than 365 trap tapes examined, the two microscopic traverses strongly correlated for counts of Alternaria spores (ICC=0.95, 95% CI 0.94-0.96). Alternaria was detected in both towns throughout the two year period with peaks in spore concentrations reflecting the season of crop harvesting in each region. Individual exposure to spores was examined. Thirty three subjects (adults and children from nine families) wore nasal air samplers and personal air samplers both inside and outside their homes. The effects of activity, location, age on the inhalation of Alternaria spores and variation between individuals in the same environment were determined. Every subject inhaled Alternaria spores. Personal exposure to Alternaria in the home environment varied substantially between subjects. Levels of fungal spores inhaled were higher during periods of activity than during rest, and higher while subjects were outdoors than indoors. During outdoor activity, the number of Alternaria spores inhaled ranged from 4 to 794 (median 11) spores/hr. Sources of airborne spores was investigated by sampling air above wheat and cotton crops near the towns during harvesting and non-harvesting periods, in a grain and cotton seed storage shed, and a cotton gin. Substantially higher concentrations were detected above crops during harvesting periods compared to non-harvesting periods. Peaks were associated with harvesting and other activities where plants were manipulated. By regression analysis spore concentrations in both towns were modelled against those detected above crops and with weather variables. Only one crop sampling period (cotton harvest) independently correlated with concentrations in town. Analysis combining all data showed concentrations of spores above crops correlated with spore concentrations in the town when lagged by one day. Variables of rainfall and maximum temperature influenced concentrations in both towns, and wind direction in Wagga Wagga alone. Parents of asthmatic children were asked by questionnaire in which locations symptoms were provoked. Asthma was reported to be exacerbated at grain farms and with disturbance of local vegetation in town and home gardens. Nasal sampling confirmed that activities that disturbed dust or vegetation increased the inhalation of spores. The factors that release allergen from spores were determined in a modified Halogen immunoassay. Approximately 60% of spores released allergen, and the proportion was influenced by isolate, nutrient availability, viability, and not influenced by sunlight or culture age up to 21 days. Germinating the spores significantly increased the proportion that released total allergen and Alt a 1 (p<0.0001). Alt a 1 appears to be a minor contributor to the total allergen released from spores except when spores have germinated. Conclusions: People living in inland rural regions of Australia are exposed to substantial quantities of allergenic spores of Alternaria. Exposure is a highly personal event and is largely determined by disturbance of local vegetation releasing spores such as from nearby crops by wind, harvesting, slashing, transport and processing of produce, and from within town and home gardens. Most spores inhaled are likely to be allergenic, with potency potentially increasing with viability.
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Prevalence and distribution of Alternaria allergens in rural New South Wales, AustraliaMitakakis, Teresa Zinovia January 2001 (has links)
In rural inland, south-eastern Australia, allergy to the fungus Alternaria is prevalent and an important risk factor for asthma. The aim of the thesis was to investigate the distribution and factors influencing allergens of Alternaria in the air. As airborne allergenic spores were thought to arise from harvesting of nearby crops, two towns with different agricultural practices were studied. Moree has two crop harvesting periods in summer and autumn whilst Wagga Wagga has one harvesting period in summer. Over two years, air was sampled daily in Wagga Wagga and Moree using Burkard traps. The reliability of measurements from a single site to represent the distribution of airborne concentrations of spores across each town was examined using data from three traps simultaneously, sited 2.0 to 4.9 km apart, over four weeks. Substantial intra-class correlation coefficients (ICC) were observed between the three sampling sites across both towns (ICC=0.52, 95% CI 0.30-0.71 to 0.76, 95% CI 0.61-0.87) when counts of Alternaria spores were relatively high. The correlation was poor when counts were low. Of more than 365 trap tapes examined, the two microscopic traverses strongly correlated for counts of Alternaria spores (ICC=0.95, 95% CI 0.94-0.96). Alternaria was detected in both towns throughout the two year period with peaks in spore concentrations reflecting the season of crop harvesting in each region. Individual exposure to spores was examined. Thirty three subjects (adults and children from nine families) wore nasal air samplers and personal air samplers both inside and outside their homes. The effects of activity, location, age on the inhalation of Alternaria spores and variation between individuals in the same environment were determined. Every subject inhaled Alternaria spores. Personal exposure to Alternaria in the home environment varied substantially between subjects. Levels of fungal spores inhaled were higher during periods of activity than during rest, and higher while subjects were outdoors than indoors. During outdoor activity, the number of Alternaria spores inhaled ranged from 4 to 794 (median 11) spores/hr. Sources of airborne spores was investigated by sampling air above wheat and cotton crops near the towns during harvesting and non-harvesting periods, in a grain and cotton seed storage shed, and a cotton gin. Substantially higher concentrations were detected above crops during harvesting periods compared to non-harvesting periods. Peaks were associated with harvesting and other activities where plants were manipulated. By regression analysis spore concentrations in both towns were modelled against those detected above crops and with weather variables. Only one crop sampling period (cotton harvest) independently correlated with concentrations in town. Analysis combining all data showed concentrations of spores above crops correlated with spore concentrations in the town when lagged by one day. Variables of rainfall and maximum temperature influenced concentrations in both towns, and wind direction in Wagga Wagga alone. Parents of asthmatic children were asked by questionnaire in which locations symptoms were provoked. Asthma was reported to be exacerbated at grain farms and with disturbance of local vegetation in town and home gardens. Nasal sampling confirmed that activities that disturbed dust or vegetation increased the inhalation of spores. The factors that release allergen from spores were determined in a modified Halogen immunoassay. Approximately 60% of spores released allergen, and the proportion was influenced by isolate, nutrient availability, viability, and not influenced by sunlight or culture age up to 21 days. Germinating the spores significantly increased the proportion that released total allergen and Alt a 1 (p<0.0001). Alt a 1 appears to be a minor contributor to the total allergen released from spores except when spores have germinated. Conclusions: People living in inland rural regions of Australia are exposed to substantial quantities of allergenic spores of Alternaria. Exposure is a highly personal event and is largely determined by disturbance of local vegetation releasing spores such as from nearby crops by wind, harvesting, slashing, transport and processing of produce, and from within town and home gardens. Most spores inhaled are likely to be allergenic, with potency potentially increasing with viability.
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The use of remote sensing data for broad acre grain crop monitoring in Southeast AustraliaCoppa, Isabel Patricia Maria, Isabel.coppa@csw.com.au January 2006 (has links)
In 2025, there will be almost 8 billion people to feed as the worlds population rapidly increases. To meet domestic and export demands, Australian grain productivity needs to approximately triple in the next 20 years, and this production needs to occur in an environmentally sustainable manner. The advent of Hi-tech Precision Farming in Australia has shown promise in recent time to optimize the use of resources. Most
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Learning from the past for sustainability: towards an integrated approachProust, Katrina Margaret, kproust@cres10.anu.edu.au January 2004 (has links)
The task of producing policies for the management of Earth’s natural resources is a problem of the gravest concern worldwide. Such policies must address both responsible use in the present and the sustainability of those finite resources in the future. Resources are showing the adverse results of generations of exploitation, and communities fail to see the outcomes of past policies that have produced, and continue to produce, these results. They have not learned from past policy failures, and consequently fail to produce natural resource management (NRM) policies that support sustainable development.¶
It will be argued that NRM policy makers fail to learn from the past because they do not have a good historical perspective and a clear understanding of the dynamics of the complex human-environment system that they manage. It will also be argued that historians have not shown an interest in collaborating with policy makers on these issues, even though they have much to offer. Therefore, a new approach is proposed, which brings the skills and understanding of the trained historian directly into the policy arena.¶
This approach is called Applied Environmental History (AEH). Its aims are to help establish an area of common conceptual ground between NRM practitioners, policy makers, historians and dynamicists; to provide a framework that can help NRM practitioners and policy makers to take account of the historical and dynamical issues that characterise human-environment relationships; and to help NRM practitioners and policy makers improve their capacity to learn from the past.
Applied Environmental History captures the characteristics of public and applied history and environmental history. In order to include an understanding of feedback dynamics in human-environment systems, it draws on concepts from dynamical systems theory. Because learning from the past is a particular form of learning from experience, AEH also draws on theories of cognitive adaptation.¶
Principles for the application of AEH are developed and then tested in an exploratory study of irrigation development that is focused on the NRM issue of salinity. Since irrigation salinity has existed for centuries, and is a serious environmental problem in many parts of the world, it is a suitable NRM context in which to explore policy makers' failure to learn from the past. AEH principles guide this study, and are used, together with insights generated from the study, as the basis for the design of AEH Guidelines.
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