645 research outputs found

    Vegetation and peat characteristics of restiad bogs on Chatham Island (Rekohu), New Zealand

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    Restiad bogs dominated by Sporadanthus traversii on Chatham Island, New Zealand, were sampled to correlate vegetation patterns and peat properties, and to compare with restiad systems dominated by Sporadanthus ferrugineus and Empodisma minus in the Waikato region, North Island, New Zealand. Classification and ordination resulted in five groups that reflected a disturbance gradient. The largest S. traversii group, which comprised plots from central, relatively intact bogs, had the lowest levels of total nitrogen (mean 1.20 mg cm-3), total phosphorus (mean 0.057 mg cm-3), total potassium (mean 0.083 mg cm-3), and available phosphorus (mean 18.6 μg cm-3). Modification by drainage, stock, and fires resulted in a decline of S. traversii and an increase of Gleichenia dicarpa fern cover, together with elevated peat nutrient levels and higher bulk density. Compared with peat dominated by Sporadanthus ferrugineus or Empodisma minus in relatively unmodified Waikato restiad bogs, Chatham Island peat under S. traversii has significantly higher total potassium, total nitrogen, available phosphorus, bulk density, and von Post decomposition indices, and significantly lower pH. Sporadanthus traversii and Empodisma minus have similar ecological roles in restiad bog development, occupying a relatively wide nutrient range, and regenerating readily from seed after fire. Despite differences in root morphology, S. traversii and E. minus are the major peat formers in raised restiad bogs on Chatham Island and in Waikato, respectively, and could be regarded as ecological equivalents

    The permafrost carbon inventory on the Tibetan Plateau : a new evaluation using deep sediment cores

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    Acknowledgements We are grateful for Dr. Jens Strauss and the other two anonymous reviewers for their insightful comments on an earlier version of this MS, and appreciate members of the IBCAS Sampling Campaign Teams for their assistance in field investigation. This work was supported by the National Basic Research Program of China on Global Change (2014CB954001 and 2015CB954201), National Natural Science Foundation of China (31322011 and 41371213), and the Thousand Young Talents Program.Peer reviewedPostprin

    Vertical zonation of testate amoebae in the Elatia Mires, northern Greece : palaeoecological evidence for a wetland response to recent climate change or autogenic processes?

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    The Elatia Mires of northern Greece are unique ecosystems of high conservation value. The mires are climatically marginal and may be sensitive to changing hydroclimate, while northern Greece has experienced a significant increase in aridity since the late twentieth century. To investigate the impact of recent climatic change on the hydrology of the mires, the palaeoecological record was investigated from three near-surface monoliths extracted from two sites. Testate amoebae were analysed as sensitive indicators of hydrology. Results were interpreted using transfer function models to provide quantitative reconstructions of changing water table depth and pH. AMS radiocarbon dates and 210Pb suggest the peats were deposited within the last c. 50 years, but do not allow a secure chronology to be established. Results from all three profiles show a distinct shift towards a more xerophilic community particularly noted by increases in Euglypha species. Transfer function results infer a distinct lowering of water tables in this period. A hydrological response to recent climate change is a tenable hypothesis to explain this change; however other possible explanations include selective test decay, vertical zonation of living amoebae, ombrotrophication and local hydrological change. It is suggested that a peatland response to climatic change is the most probable hypothesis, showing the sensitivity of marginal peatlands to recent climatic change

    Home: The place the older adult can not imagine living without

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    <p>Abstract</p> <p>Background</p> <p>Rapidly aging populations with an increased desire to remain at home and changes in health policy that promote the transfer of health care from formal places, as hospitals and institutions, to the more informal setting of one's home support the need for further research that is designed specifically to understand the experience of home among older adults. Yet, little is known among health care providers about the older adult's experience of home. The aim of this study was to understand the experience of home as experienced by older adults living in a rural community in Sweden.</p> <p>Methods</p> <p>Hermeneutical interpretation, as developed by von Post and Eriksson and based on Gadamer's philosophical hermeneutics, was used to interpret interviews with six older adults. The interpretation included a self examination of the researcher's experiences and prejudices and proceeded through several readings which integrated the text with the reader, allowed new questions to emerge, fused the horizons, summarized main and sub-themes and allowed a new understanding to emerge.</p> <p>Results</p> <p>Two main and six sub-themes emerged. Home was experienced as the place the older adult could not imagine living without but also as the place one might be forced to leave. The older adult's thoughts vacillated between the well known present and all its comforts and the unknown future with all its questions and fears, including the underlying threat of loosing one's home.</p> <p>Conclusions</p> <p>Home has become so integral to life itself and such an intimate part of the older adult's being that when older adults lose their home, they also loose the place closest to their heart, the place where they are at home and can maintain their identity, integrity and way of living. Additional effort needs to be made to understand the older adult's experience of home within home health care in order to minimize intrusion and maximize care. There is a need to more fully explore the older adult's experience with health care providers in the home and its impact on the older adult's sense of "being at home" and their health and overall well-being.</p

    Estimating Demand for Infrastructure in Energy, Transport, Telecommunications, Water, and Sanitation in Asia and the Pacific: 2010-2020

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    Infrastructure plays a key role in promoting and sustaining rapid economic growth. Properly designed infrastructure can also make growth more inclusive by sharing its benefits with poorer groups and communities, especially by connecting remote areas and small and landlocked countries to major business centers. Even if the Asia-Pacific region has witnessed progress in infrastructure development, the growth of infrastructure lags behind its economic growth, and also behind international standards of infrastructure quantity and quality. Inadequate infrastructure can hamper the potential economic growth of Asian countries, weaken their international competitiveness, and adversely affect their poverty reduction efforts. The circumstances and effects of the recent economic and financial crisis provide a number of reasons to further develop national and regional infrastructure in Asia. Among these reasons is that regional infrastructure enhances competitiveness and productivity, which could help in economic recovery and in sustaining growth in the medium to long-term. Regional infrastructure also helps increase standard of living and reduce poverty by connecting isolated places and people with major economic centers and markets, narrowing the development gap among Asian economies. This paper estimates the need for infrastructure investment, including energy, transport, telecommunications, water, and sanitation during 2010-2020, in order to meet growing demands for services and facilitate further rapid growth in the region. By using top-down and bottom-up approaches, this paper provides a comprehensive estimate of Asia's need for infrastructure services. The estimates show that developing countries in Asia require financing of US776billionperyearfornational(US776 billion per year for national (US747 billion) and regional (US$29 billion) infrastructure during 2010-2020 to meet growing demand

    Shear Strength Parameters of Improved Peat by Chemical Stabilizer.

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    The present research aimed to discuss the applicability of cationic grouts in geotechnical engineering. The effects of several cationic stabilizers such as monovalent (sodium silicate), divalent (calcium oxide and calcium chloride), and trivalent (aluminum hydroxide) were investigated on shear strength improvement of tropical peat samples. The unconfined compressive strength (UCS) tests were performed after the time frame of 7, 21, and 30 days as curing time, respectively. Apart from the physicochemical characteristics of the stabilized peat, scanning electron microscopy and energy-dispersive X-ray spectroscopy tests were also carried out to study the ongoing microstructural changes. It is to be noted that the shear strength values for peat samples rose to 8, 6, 6, and 4 % of sodium silicate, calcium oxide, calcium chloride, and aluminum hydroxide, respectively. The highest observed UCS outcome is the one taken from the calcium oxide where the UCS of treated peat after 30-day curing time increased to 76 kPa. The strength changes resulted from the various cationic stabilizers can best be explained via the consideration within the mineralogical composition as well as those physicochemical changes happening in the peat
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