Copyright (c) 2010 All rights reserved. http://works.bepress.com/kathryn_taffs Recent documents in Kathryn H Taffs en-us Sun, 24 Jan 2010 17:01:33 PST 3600 http://works.bepress.com/kathryn_taffs/61 http://works.bepress.com/kathryn_taffs/61 Sun, 29 Nov 2009 16:26:47 PST Coastal peatlands are a rare ecosystem throughout the world. They are highly valued for their ecological importance and functions. However, many coastal peatlands have been degraded and/or destroyed by the development of the coastal plain for urban and agricultural land-uses. At Byron Bay, northern New South Wales, Australia, a large coastal peatland is located parallel to the present coastline. A palaeoecological study was conducted to investigate the use of microfossils in researching peatlands and to identify the coastal evolution of this coastal plain. A 5.2 metre core was retrieved using a Vibracorer. The core was sub-sectioned and analysed for diatoms, phytoliths, pollen and 14C AMS dates were obtained. The dates show that the surface peat has been forming since before 5000 cal. years BP. Lithological and dating results indicate that sea level has been stable throughout that time allowing the continuous development of the peatland. Prior to 5000 cal. years BP sea level was slightly higher than present and estuarine mud was deposited at the study site. Diatom preservation was adequate in the upper parts of the core to retrieve environmental information and provide indicative trends at depths in the core. The diatom results show that Eunotia and Nitzschia genus were dominant in the peat layer indicating the freshwater, acidic nature of the peatland. Nitzschia fonticola was the dominant diatom preserved in the estuarine mud beneath the peat layer indicating the robust nature of the diatom frustule. During the time of peat deposition, pollen and phytolith records indicate that this area was a forested peatland. In most recent times it was dominated by Myrtaceae tree species with Cyperaceae and Restionaceae as the dominant peat forming vegetation. This study shows that a multi-proxy approach using microfossils such as diatoms and phytoliths, can be successfully used to identify the environmental history of coastal peatland sites. Such baseline information is essential to improve the management and conservation efforts within these rare ecosystems. Kathryn H. Taffs http://works.bepress.com/kathryn_taffs/62 http://works.bepress.com/kathryn_taffs/62 Sun, 29 Nov 2009 16:26:47 PST Addressing environmental problems in estuaries is a worldwide problem. Establishing benchmarks and targets for management is critical, whether the aim is conservation, restoration or 'sustainable wise use'. Palaeoecological techniques have rapidly improved during the past decade, particularly with advances in methods that allow high resolution quantitative assessments of environmental change, allowing pre-impact conditions, the rate, extent and direction of change, and range of natural variability to be determined. Australian estuarine ecosystems are qualitatively different to the often more well-studied estuaries in North America and Europe, which means site-specific studies of Australian estuaries are needed to inform management. While a potentially useful and valuable tool, palaeoecological techniques have not yet been widely adopted and practically implemented as part of estuarine management strategies and policy frameworks in Australia.We discuss the role palaeoecological techniques have to play in estuarine management and current problems limiting their adoption and implementation. We aim to encourage communication and dialogue between scientists and environmental managers about the potential for widespread practical adoption and implementation of palaeoecological techniques into Australian estuarine science, management and policy frameworks. Krystyna M. Saunders http://works.bepress.com/kathryn_taffs/60 http://works.bepress.com/kathryn_taffs/60 Wed, 30 Sep 2009 21:43:34 PDT William E. Boyd http://works.bepress.com/kathryn_taffs/57 http://works.bepress.com/kathryn_taffs/57 Sun, 19 Apr 2009 22:45:29 PDT At the end of 1997, the Western Division of New South Wales had 22 reserves with a total extent of 9458 km2 or 2.9% of the region. We used five measures to follow the effectiveness of the reserve system as it developed between 1960 and 1997. Two of the measures -- number and total extent of reserves -- are basic statistics in any review of protected areas. The other three measures concern how well the reserve system sampled the region's land types (e.g. ecosystems, vegetation types), defined here as land systems mapped at 1:250,000. The first of these measures was representativeness -- the number of land systems sampled to a threshold level. The second was efficiency -- the proportion of the reserve system contributing to, but not in excess of, conservation targets set for each land system. The third measure of sampling effectiveness was vulnerability bias -- the extent to which reserves have been dedicated in parts of the region with most risk of vegetation loss. The representativeness of the reserve system at the end of 1997 was very low. Results for efficiency showed that a substantial part of the reserve system was not contributing to conservation targets. This partly reflected extensions of reserves to improve their design, highlighting the trade-off between design and efficiency. Values for vulnerability bias were close to those expected if reservation had been indifferent to risk of vegetation loss from clearing or cropping. Higher values would be expected if reservation had been intended to secure good examples of the more vulnerable land systems before clearing or cropping compromised conservation targets. Fluctuations in efficiency and vulnerability bias since 1960 can be related to the establishment and extension of individual reserves. We finish the paper by placing our measures of effectiveness in the context of a more comprehensive list needed to deal with issues such as environmental gradients and species' requirements for long-term persistence. R L. Pressey http://works.bepress.com/kathryn_taffs/56 http://works.bepress.com/kathryn_taffs/56 Sun, 19 Apr 2009 22:45:26 PDT The role of surface water drainage in environmental change in Australia is rarely appreciated. Drains can modify surface water hydrology, not only altering flow regimes but also rapidly dispersing contaminants and altering the natural hydrological balance of associated flora and fauna. Yet drainage continues to be considered a viable management strategy rather than as a cause of land degradation. The impact of surface water drainage in an inherently saline area of South Australia, the Upper South East, is investigated. Surface water drains were constructed by developers in an attempt to increase the area of land available and viable for agricultural land use. Drainage strategies altered the natural direction, magnitude and frequency of surface water flow. The Upper South East has experienced periods of both increased surface water and flooding, and surface water deficit, in the past one hundred years. The region now receives less surface water than under pre-European conditions, but local runoff is channelled into and through the wetlands more rapidly than before European settlement. Future management strategies are likely to continue this trend, to the detriment of remnant natural wetlands. Kathryn H. Taffs http://works.bepress.com/kathryn_taffs/55 http://works.bepress.com/kathryn_taffs/55 Sun, 19 Apr 2009 22:45:25 PDT Diatom-based paleolimnological studies are being increasingly used to track anthropogenic change in estuaries. Little is known, however, about the direction and nature of longterm environmental changes in Australian estuaries. In this study, shifts in diatom assemblages preserved in a 210Pb and C14 AMS dated sediment core from Tuckean Swamp were analysed to determine environmental changes that had taken place as a result of changing land-use practices. Prior to European impact, the diatom assemblage remained relatively stable and was dominated by Actinocyclus normanii and Diploneis smithii. An increasing dominance of Cyclotella meneghiniana correlates well with changed land use activities in the catchment area and indicates an increase of freshwater influence in the swamp's environment. A major shift in species composition began ~1970, Eunotia flexuosa becoming dominant. The assemblage shifts recorded at this site appear to be consistent with environmental changes triggered by human activities such as vegetation clearance, drainage and the construction of a barrage. This study demonstrates the use of paleolimnoology in an estuarine environment to provide pre-impact data necessary for management of the aquatic environment. Kathryn H. Taffs http://works.bepress.com/kathryn_taffs/54 http://works.bepress.com/kathryn_taffs/54 Sun, 19 Apr 2009 22:45:24 PDT This study provides an introduction to a microwave digestion technique for the extraction of fossil diatoms from sediments. The microwave technique is compared with the standard diatom extraction technique of Battarbee (Diatom analysis. In: Berglund B.E. (ed.), Handbook of Holocene Palaeoecology and Palaeohydrology. John Wiley and Sons) that uses a combination of dilute hydrochloric acid and hydrogen peroxide and the advantages and disadvantages of their use are discussed. The results suggest that the microwave technique is fast, inexpensive and most importantly produces replicable fossil diatom assemblage data. Small samples sizes are used (0.3 g) for the microwave method thus lower quantities of chemicals are required (6 ml), which significantly decreases the cost of sample processing. Our results show that the microwave digestion technique is a viable alternative that will produce similar results within a shorter period of time. Jeffrey F. Parr http://works.bepress.com/kathryn_taffs/53 http://works.bepress.com/kathryn_taffs/53 Sun, 19 Apr 2009 22:45:23 PDT This book provides a basis for developing skills in the most fundamental techniques used, and an overview of the more advanced methods and equipment available for studying, recording, interpreting and communicating information about the environment. Includes 140 useful exercises that encourage practical application of theories. William E. Boyd http://works.bepress.com/kathryn_taffs/52 http://works.bepress.com/kathryn_taffs/52 Sun, 19 Apr 2009 22:45:22 PDT Beach debris items were collected and categorized during surveys of five isolated beaches on the northern New South Wales coastline in September 2003. The selected beaches covered more than 21 km of contiguous coastline. Litter density and distribution per 500 m segment was calculated. The highest density of litter was found on the most isolated beaches with little public access but no protection by headlands from the ocean swells. The results indicate that management of beach debris needs to focus on reducing the litter entering the marine environment. Kathryn H. Taffs http://works.bepress.com/kathryn_taffs/51 http://works.bepress.com/kathryn_taffs/51 Sun, 19 Apr 2009 22:45:21 PDT 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 which 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 surface water. This is due to an increase of throughflow of surface water, a result of constructed drainage systems flushing salts from the wetlands. Despite the freshening of wetlands they continue to degrade due to the changed hydrology, an impact of the drainage structures. Kathryn H. Taffs http://works.bepress.com/kathryn_taffs/50 http://works.bepress.com/kathryn_taffs/50 Sun, 19 Apr 2009 22:45:19 PDT Scheduling conservation action is necessary when the available resources for conservation are insufficient to adequately protect all of the natural features (e.g. species, vegetation types, ecosystems) in a region, at least in the short-term. We propose an approach to scheduling conservation action in production landscapes. It is based on two characteristics of potential conservation areas. The first is vulnerability -- the likelihood or imminence of destruction or alteration of native vegetation. The second is irreplaceability -- the likelihood that an area will be needed to contribute to a set of conservation targets nominated for the region's features. We argue that highest priority for conservation action should go to those areas with both high vulnerability (urgent protection needed to avoid destruction) and high irreplaceability (few or no alternatives if destroyed). To establish the context and rationale for our approach, we review some previous methods for scheduling nature conservation. We then apply our approach to the Western Division of New South Wales, a region of about 325,000 km2, by deriving information on the vulnerability of 248 land systems to two threatening processes (clearing and cropping) and measuring the irreplaceability of potential conservation areas. Our results are maps of areas where conservation action is most urgently needed if regional conservation targets are not to be compromised. R L. Pressey http://works.bepress.com/kathryn_taffs/49 http://works.bepress.com/kathryn_taffs/49 Sun, 19 Apr 2009 22:45:18 PDT A wide variety of scientific disciplines require representative samples of benthic sediment. As a result, a large range of sampling devices have been developed, each best suited to a particular set of conditions. However, all sediment sampling devices have inherent design problems that affect the degree to which samples represent the intact sediment. These issues are summarised, and a new corer design (the LOG corer) is presented and discussed. The LOG corer is a remotely-operated light-weight gravity corer suitable for obtaining relatively undisturbed short sediment cores in soft lacustrine sediments. Christopher M. Lane http://works.bepress.com/kathryn_taffs/48 http://works.bepress.com/kathryn_taffs/48 Sun, 19 Apr 2009 22:45:17 PDT Kathryn H. Taffs http://works.bepress.com/kathryn_taffs/47 http://works.bepress.com/kathryn_taffs/47 Sun, 19 Apr 2009 22:45:16 PDT Artificial substrata have been used in diatom studies for almost 100 years. However, concern still exists over whether diatom communities developing on artificial substrata accurately represent communities developing on natural substrata. This study compares the diatom communities colonising glass slides and clay tiles in two coastal dune lakes, and compares these communities to the naturally occurring communities in the epipelon, epilithon, and epiphyton. Both glass microslides and clay tiles, incubated for three separate periods ranging from 29 to 68 days, resulted in replicate substratum samples supporting similar diatom community compositions at each site. The degree of variation between artificial substrata communities at different sites, and between the two artificial substrata types, was generally no more than the degree of variation between communities on different types of natural substrata. Additionally, the composition of the diatom communities on the artificial substrata was representative of the community composition on the natural substrata. The effects of incubation period and siting are discussed. Christopher M. Lane http://works.bepress.com/kathryn_taffs/46 http://works.bepress.com/kathryn_taffs/46 Sun, 19 Apr 2009 22:45:14 PDT Kathryn H. Taffs http://works.bepress.com/kathryn_taffs/45 http://works.bepress.com/kathryn_taffs/45 Sun, 19 Apr 2009 22:45:13 PDT Jeffrey F. Parr http://works.bepress.com/kathryn_taffs/44 http://works.bepress.com/kathryn_taffs/44 Sun, 19 Apr 2009 22:45:12 PDT Jeffrey F. Parr http://works.bepress.com/kathryn_taffs/42 http://works.bepress.com/kathryn_taffs/42 Sun, 19 Apr 2009 22:45:11 PDT Kathryn H. Taffs http://works.bepress.com/kathryn_taffs/41 http://works.bepress.com/kathryn_taffs/41 Sun, 19 Apr 2009 22:45:10 PDT Kathryn H. Taffs http://works.bepress.com/kathryn_taffs/39 http://works.bepress.com/kathryn_taffs/39 Sun, 19 Apr 2009 22:45:08 PDT Jeffrey F. Parr