The Mesopotamian marshlands are one of the most internationally important wetlands in the Middle East as it constitutes a nursing ground for many species of birds migrating from North Europe as well as for its rich biodiversity. These... more
The Mesopotamian marshlands are one of the most internationally important wetlands in the Middle East as it constitutes a nursing ground for many species of birds migrating from North Europe as well as for its rich biodiversity. These marshlands have undergone significant environmental changes during the last three decades owing to decreasing freshwater discharge which has led to water quality deterioration and a changing hydrological regime. This has had a considerable effect on the fauna and flora of the marshes, diminishing their ecological value and significance. The work presented here is the first attempt to investigate the marshes environmental condition during the past two centuries using paleolimnology, specifically dia-toms as bioindicators in a sediment core. 80 species of diatom belonging to 35 genera were identified. The taxa encountered in the core are a mixture of fresh and brackish water forms. These are epiphytic and benthic taxa, no planktonic species were found. The fossil diatom community shows that the marshes have been exposed to different periods of salinization as well as eutrophication. The dominance of pollution tolerant species in the core indicates poor water quality for the past 160 years. Paleolimnology is important to understand past environmental conditions and forms a milestone for successful future restoration process. Further work is required to extend the time scale to identify natural ecological states and thresholds to guide international aid restoration projects.
Disturbance plays an important role in plant life history strategies and has been documented as both enhancing and threatening populations of the vulnerable grass Arthraxon hispidus (Thunb.) Makino (hairy jointgrass) on the NSW north... more
Disturbance plays an important role in plant life history strategies and has been documented as both enhancing and threatening populations of the vulnerable grass Arthraxon hispidus (Thunb.) Makino (hairy jointgrass) on the NSW north coast. Mechanical disturbance (slashing) is often used in A. hispidus conservation management, but many Australian plants are adapted to fire-based disturbance regimes. In this study we undertook a field burning experiment, along with soil seed bank sampling and germination trials, to explore how fire influences A. hispidus population dynamics in terms of plant recruitment and seed bank fluctuations. We found that winter burning strongly promoted A. hispidus spring germination without entirely depleting the residual seedbank. Although drought affected our field study population, burning also led to increased adult cover and substantial seed bank replenishment the following autumn. Exposure to a smoke treatment almost doubled the germination rate of A. h...
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Knowledge of a target species’ habitat niche and physiological tolerances is important for conservation planning. However, these factors are not well understood for the threatened annual grass Arthraxon hispidus in New South Wales (NSW).... more
Knowledge of a target species’ habitat niche and physiological tolerances is important for conservation planning. However, these factors are not well understood for the threatened annual grass Arthraxon hispidus in New South Wales (NSW). Although the species is widespread in modified environments, recent studies have suggested that several threatened wetland types may represent original native habitat for the species, but documented field examples are lacking and the species’ physiological response to soil moisture is not clear. We undertook a detailed survey of an A. hispidus population within a relatively intact native sedgeland community, and carried out a nursery experiment to test the hydrological tolerances of the species. We found that A. hispidus plants grew more vigorously in poorly drained or waterlogged conditions, suggesting that the species is well-adapted to overcome such stressors, possibly through the formation of adventitious roots, a trait shared by many wetland pl...
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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... more
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 communiti...
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The forests along the Amazon Basin produce significant quantities of organic material, a portion of which is deposited in floodplain lakes. However, potentially important effects of ongoing deforestation in the watershed on these carbon... more
The forests along the Amazon Basin produce significant quantities of organic material, a portion of which is deposited in floodplain lakes. However, potentially important effects of ongoing deforestation in the watershed on these carbon fluxes is still poorly understood. Here, a sediment core was extracted from an Amazon floodplain lake to examine the relationship between carbon burial and land cover/use. Historical records from 1942 and satellite data from 1975 were used to calculate deforestation rates between 1942 and 1975, and 1975 to 2008 in four zones with different distances from the margins of the lake and its tributaries (100, 500, 1000 and 6000-m buffers). Sediment accumulation rates were determined from the <sup>240+239</sup>Pu signatures and the excess <sup>210</sup>Pb method, reaching near 3.8 and 4.2 mm year<sup>−1</sup> in the last 60 and 120 years respectively. The average carbon burial rates ranged between...
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Research Interests: Archaeology, Earth Sciences, Geology, Australia, Quaternary, and 6 moreHolocene, Wetland, Diatom, CAPE, Dry Tropics, and Cape York
The Mesopotamian marshlands are one of the most internationally important wetlands in the Middle East as it constitutes a nursing ground for many species of birds migrating from North Europe as well as for its rich biodiversity. These... more
The Mesopotamian marshlands are one of the most internationally important wetlands in the Middle East as it constitutes a nursing ground for many species of birds migrating from North Europe as well as for its rich biodiversity. These marshlands have undergone significant environmental changes during the last three decades owing to decreasing freshwater discharge which has led to water quality deterioration and a changing hydrological regime. This has had a considerable effect on the fauna and flora of the marshes, diminishing their ecological value and significance. The work presented here is the first attempt to investigate the marshes environmental condition during the past two centuries using paleolimnology, specifically diatoms as bioindicators in a sediment core. 80 species of diatom belonging to 35 genera were identified. The taxa encountered in the core are a mixture of fresh and brackish water forms. These are epiphytic and benthic taxa, no planktonic species were found. The fossil diatom community shows that the marshes have been exposed to different periods of salinization as well as eutrophication. The dominance of pollution tolerant species in the core indicates poor water quality for the past 160 years. Paleolimnology is important to understand past environmental conditions and forms a milestone for successful future restoration process. Further work is required to extend the time scale to identify natural ecological states and thresholds to guide international aid restoration projects.
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Wetland degradation in the Upper South East of South Australia is an urgent management concern. Scant recent environmental data is available for the region and long-term monitoring data is lacking. Usually a palaeoecological analysis is... more
Wetland degradation in the Upper South East of South Australia is an urgent management concern. Scant recent environmental data is available for the region and long-term monitoring data is lacking. Usually a palaeoecological analysis is able to reveal environmental change in the medium-to long-term past. However, the region is not conducive to palaeoecological investigation due to a fluctuating upper groundwater aquifer and alkaline soils whiclh have destroyed most microfossils. It was found that the diatom assemblage was preserved in the wetlands of the region for the period of European settlement. Analysis of the diatom assemblage enabled production of an inferred salinity curve. In combination with a small amount of historical information that was available, the salinity trend for the wetlands, for the period of European agricultural activities, was identified. It was found that, while groundwater salinity has been increasing, the wetland areas have experienced a freshening of su...
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Point-sampling of water is often referred to as an inaccurate and crude method for use in estuaries; however, budgetary, spatial and time constraints often leave it as the only feasible option. The present paper investigates the... more
Point-sampling of water is often referred to as an inaccurate and crude method for use in estuaries; however, budgetary, spatial and time constraints often leave it as the only feasible option. The present paper investigates the relationship between spring water quality and diatom sampling of 52 eastern Australian subtropical estuaries and the OzCoasts determined classification of estuarine condition. In general, estuarine health decreases along the total phosphorus (TP), total nitrogen (TN) and the centric to pennate diatom ratio gradients. However, although there is a general trend, results are varied within each class, with some estuaries classed as extensively modified, recording low nutrient conditions. Principal components analysis (PCA) indicated that 55% of the variance among sites is explained by the first and second axes, with TN, TP, TN : TP, latitude and pH having high correlation with PCA Axis 1, and temperature, conductivity and the centric to pennate diatom ratio bein...
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Research Interests: Geography, Diversity, Australia, Ecology, Protected areas, and 15 moreBiological Sciences, Biodiversity Conservation, Environmental Sciences, Biological Conservation, Birds, Nature Conservation, New South Wales, Efficiency, Protected Area, Hotspots, Protected Areas, Conservation Priorities, Cropping, Land Clearing, and Conservation value
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Research Interests: Geography, Archaeology, Earth Sciences, Atmospheric Science, Paleoecology, and 6 moreChronology, Peat, Wetland, NSW, Armidale, and December
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Context The ability of ectothermic stream invertebrates to adapt to the predicted increases in mean and extreme stream temperatures is crucial to ensuring they continue to exist. Aims To examine the plasticity of thermal limits of... more
Context The ability of ectothermic stream invertebrates to adapt to the predicted increases in mean and extreme stream temperatures is crucial to ensuring they continue to exist. Aims To examine the plasticity of thermal limits of Australian Paratya spp. (Decapoda, Atyidae) from streams in eastern New South Wales (NSW). We hypothesised that the upper lethal temperature (ULT, as indicated by the median lethal temperature, LT50) would be higher for warm water-acclimated shrimp individuals than for winter-acclimatised shrimp individuals because of the importance of acclimatisation temperature. Methods Controlled experiments were undertaken to determine the ULT by using ramping assays for winter field-acclimatised and warm water laboratory-acclimated Paratya spp. Key results Warm water-acclimated shrimp individuals demonstrated a significantly higher LT50 of 36.1°C than did winter-acclimatised shrimp individuals at 34.6°C. Paratya spp. exhibited a limited plasticity for acclimation to w...
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ABSTRACT The use of diatoms as bio-indicators of water quality is common in temperate regions worldwide. However, less attention has been accorded to sub-tropical regions, particularly in Australia. This study assessed the value of diatom... more
ABSTRACT The use of diatoms as bio-indicators of water quality is common in temperate regions worldwide. However, less attention has been accorded to sub-tropical regions, particularly in Australia. This study assessed the value of diatom communities to infer water quality in a sub-tropical riverine system. Epilithic diatom and water samples were collected monthly from an east Australian river. Principal components analysis showed that the Lower Catchment sites were more strongly influenced by the measured environmental variables differentiating them from the Upper Catchment sites. Canonical Correspondence Analysis showed electrical conductivity and total phosphorus strongly influenced the diatom community distribution. The study revealed diatom species that are robust bio-indicators of water quality in this sub-tropical catchment. Cocconeis placentula, C. placentula var lineata, Gomphonema spec 2 and Tabellaria flocculosa were identified as indicators of moderate water quality. Bacillaria paradoxa, Navicula cryptocephala, Navicula mutica var mutica and Achnanthes fogedii were identified as indicators of poor water quality. This study identified that diatoms are effective indicators of water quality. Further research is required to develop a diatom biological index applicable to sub-tropical east Australian river systems to improve the effectiveness of environmental monitoring and sustainable river management.
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... Parr, JF, Kerr, G, Arthur, J & Taffs, KH 2008, 'Fires impact on an acidic peatland in northeastern NSW: implications for the interpretation of fire histories, pyrite formation and loss of organic carbon', in M Del Pilar... more
... Parr, JF, Kerr, G, Arthur, J & Taffs, KH 2008, 'Fires impact on an acidic peatland in northeastern NSW: implications for the interpretation of fire histories, pyrite formation and loss of organic carbon', in M Del Pilar Babot & MA Korstanje (eds), Matices interdisciplinarios en estudios ...
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... Parr, JF, Kerr, G, Arthur, J & Taffs, KH 2008, 'Fires impact on an acidic peatland in northeastern NSW: implications for the interpretation of fire histories, pyrite formation and loss of organic carbon', in M Del Pilar... more
... Parr, JF, Kerr, G, Arthur, J & Taffs, KH 2008, 'Fires impact on an acidic peatland in northeastern NSW: implications for the interpretation of fire histories, pyrite formation and loss of organic carbon', in M Del Pilar Babot & MA Korstanje (eds), Matices interdisciplinarios en estudios ...
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Australian researchers are creating, and environmental policy makers and managers are using, palaeo-environmental and ecosystem service information. Innovations in ecosystem services and palaeo-environmental science; better and cheaper... more
Australian researchers are creating, and environmental policy makers and managers are using, palaeo-environmental and ecosystem service information. Innovations in ecosystem services and palaeo-environmental science; better and cheaper local studies and regional syntheses, knowledge of extreme conditions Contributing to 5 important contexts of use at the moment: discussions about environmental understanding and environmental management; improving knowledge about natural resources; understanding environmental processes and resource availability; and engaging interdisciplinary approaches to address ecosystem services However this is not enough transformational changes are needed in management collaborative efforts between communities, leaders, scientists, planners and managers setting resource management objectives, anticipating consequences of trade-offs, sharing risk and providing strategies for evaluation and monitoring of ecosystem services translating the ecosystem services conce...
Australian researchers are creating, and environmental policy makers and managers are using, palaeo-environmental and ecosystem service information. Innovations in ecosystem services and palaeo-environmental science; better and cheaper... more
Australian researchers are creating, and environmental policy makers and managers are using, palaeo-environmental and ecosystem service information. Innovations in ecosystem services and palaeo-environmental science; better and cheaper local studies and regional syntheses, knowledge of extreme conditions Contributing to 5 important contexts of use at the moment: discussions about environmental understanding and environmental management; improving knowledge about natural resources; understanding environmental processes and resource availability; and engaging interdisciplinary approaches to address ecosystem services However this is not enough transformational changes are needed in management collaborative efforts between communities, leaders, scientists, planners and managers setting resource management objectives, anticipating consequences of trade-offs, sharing risk and providing strategies for evaluation and monitoring of ecosystem services translating the ecosystem services conce...
ABSTRACT Despite the great potential of palaeo-environmental information to strengthen natural resource policy, science and practical outcomes naturally occurring archives of palaeo-environmental and ecosystem service information have not... more
ABSTRACT Despite the great potential of palaeo-environmental information to strengthen natural resource policy, science and practical outcomes naturally occurring archives of palaeo-environmental and ecosystem service information have not been fully recognised or utilised to inform the development of environmental policy. In this paper, we describe how Australian palaeo-environmental science is improving environmental understanding through local studies and regional syntheses that inform us about past conditions, extreme conditions and altered ecosystem states. Australian innovations in ecosystem services research and palaeo-environmental science contribute in five important contexts: discussions about environmental understanding and management objectives, improving access to information, improved knowledge about the dynamics of ecosystem services, increasing understanding of environmental processes and resource availability, and engaging interdisciplinary approaches to manage ecosystem services. Knowledge of the past is an important starting point for setting present and future resource management objectives, anticipating consequences of trade-offs, sharing risk and evaluating and monitoring the ongoing availability of ecosystem services. Palaeo-environmental information helps reframe discussions about desirable futures and collaborative efforts between scientists, planners, managers and communities. However, further steps are needed to translate the ecosystem services concept into ecosystem services policy and tangible management objectives and actions that are useful, feasible and encompass the range of benefits to people from ecosystems. We argue that increased incorporation of palaeo-environmental information into policy and decision-making is needed for evidence-based adaptive management to enhance sustainability of ecosystem functions and reduce long-term risks.
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ABSTRACT Branched glycerol dialkyl glycerol tetraether (GDGT) distributions observed in a sediment core from Lake McKenzie were utilized to quantitatively reconstruct the pattern of mean annual air temperature (MAAT) from coastal... more
ABSTRACT Branched glycerol dialkyl glycerol tetraether (GDGT) distributions observed in a sediment core from Lake McKenzie were utilized to quantitatively reconstruct the pattern of mean annual air temperature (MAAT) from coastal subtropical eastern Australia between 37 and 18.3 cal ka BP and 14.0 cal ka BP to present. Both the reconstructed trend and amplitude of MAAT changes from the top of the sediment core were nearly identical to a local instrumental MAAT record from Fraser Island, providing confidence that in this sediment core branched GDGTs could be used to produce a quantitative record of past MAAT. The reconstructed trend of MAAT during 37 to 18.3 cal ka BP and timing of the Last Glacial Maximum (LGM) in the Lake McKenzie record were in agreement with previously published nearby marine climate records. The amplitude of lower-than-present MAAT during the LGM potentially provides information on the latitude of separation of the Tasman Front from the East Australian current in the subtropical western Pacific. The Lake McKenzie record shows an earlier onset of near modern day warm temperatures in the early Holocene compared to marine records and the presence of a warmer than present day period during the mid-Holocene.
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ABSTRACT Branched glycerol dialkyl glycerol tetraether (GDGT) distributions observed in a sediment core from Lake McKenzie were utilized to quantitatively reconstruct the pattern of mean annual air temperature (MAAT) from coastal... more
ABSTRACT Branched glycerol dialkyl glycerol tetraether (GDGT) distributions observed in a sediment core from Lake McKenzie were utilized to quantitatively reconstruct the pattern of mean annual air temperature (MAAT) from coastal subtropical eastern Australia between 37 and 18.3 cal ka BP and 14.0 cal ka BP to present. Both the reconstructed trend and amplitude of MAAT changes from the top of the sediment core were nearly identical to a local instrumental MAAT record from Fraser Island, providing confidence that in this sediment core branched GDGTs could be used to produce a quantitative record of past MAAT. The reconstructed trend of MAAT during 37 to 18.3 cal ka BP and timing of the Last Glacial Maximum (LGM) in the Lake McKenzie record were in agreement with previously published nearby marine climate records. The amplitude of lower-than-present MAAT during the LGM potentially provides information on the latitude of separation of the Tasman Front from the East Australian current in the subtropical western Pacific. The Lake McKenzie record shows an earlier onset of near modern day warm temperatures in the early Holocene compared to marine records and the presence of a warmer than present day period during the mid-Holocene.
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Research Interests: Genetics, Physiology, Environmental Science, Geochemistry, Oceanography, and 28 moreBiogeochemistry, Hydrology, Phylogeography, Toxicology, Crustacea, Biology, Ecology, Paleolimnology, Environmental Change, Multidisciplinary, FISH, Scientific, Isotopes, Educational, Estuaries, Case Study, Plankton, Dating, Sediments, Dissolution, High Temperature, Sediment, Stream, Coral, Isotope, Estuary, Subtropical Urbanism, and Human Activity(Biogeochemistry, Hydrology, Phylogeography, Toxicology, Crustacea, Biology, Ecology, Paleolimnology, Environmental Change, Multidisciplinary, FISH, Scientific, Isotopes, Educational, Estuaries, Case Study, Plankton, Dating, Sediments, Dissolution, High Temperature, Sediment, Stream, Coral, Isotope, Estuary, Subtropical Urbanism, and Human Activity)
(Biogeochemistry, Hydrology, Phylogeography, Toxicology, Crustacea, Biology, Ecology, Paleolimnology, Environmental Change, Multidisciplinary, FISH, Scientific, Isotopes, Educational, Estuaries, Case Study, Plankton, Dating, Sediments, Dissolution, High Temperature, Sediment, Stream, Coral, Isotope, Estuary, Subtropical Urbanism, and Human Activity)
Research Interests: Genetics, Physiology, Environmental Science, Geochemistry, Oceanography, and 28 moreBiogeochemistry, Hydrology, Phylogeography, Toxicology, Crustacea, Biology, Ecology, Paleolimnology, Environmental Change, Multidisciplinary, FISH, Scientific, Isotopes, Educational, Estuaries, Case Study, Plankton, Dating, Sediments, Dissolution, High Temperature, Sediment, Stream, Coral, Isotope, Estuary, Subtropical Urbanism, and Human Activity(Biogeochemistry, Hydrology, Phylogeography, Toxicology, Crustacea, Biology, Ecology, Paleolimnology, Environmental Change, Multidisciplinary, FISH, Scientific, Isotopes, Educational, Estuaries, Case Study, Plankton, Dating, Sediments, Dissolution, High Temperature, Sediment, Stream, Coral, Isotope, Estuary, Subtropical Urbanism, and Human Activity)
(Biogeochemistry, Hydrology, Phylogeography, Toxicology, Crustacea, Biology, Ecology, Paleolimnology, Environmental Change, Multidisciplinary, FISH, Scientific, Isotopes, Educational, Estuaries, Case Study, Plankton, Dating, Sediments, Dissolution, High Temperature, Sediment, Stream, Coral, Isotope, Estuary, Subtropical Urbanism, and Human Activity)