Impact of sediment type,light and nutrient availability on benthic diatom communities of a large estuarine bay: Moreton Bay,Australia     

Alistair Grinham  Deborah Gale  James Udy 《Journal of Paleolimnology》2011,46(4):511-523

Shifts in diatom species composition may be used to infer past changes in environmental conditions in fresh, estuarine and marine systems. Establishing the primary drivers of present day diatom community composition is a vital step in their use as a proxy for past conditions. Moreton Bay, Australia, has experienced extensive modification of its catchments and western and southern shorelines. Regional weather patterns and terrestrial runoff have created a gradient in water quality from relatively degraded western and southern areas to relatively pristine northern and eastern areas. The aim of this study was to examine the relative impact of short term changes to light and/or nutrient availability and long term changes in sediment type, light and nutrient availability to subtidal benthic community composition. Short term changes were imposed using a manipulative field experiment whilst long term changes were obtained from a field survey of sites across the gradient of water quality. Diatoms were found to be the dominant microalgal group at all studied sites. The diatom communities were comprised primarily of small benthic epipsammic species and community composition was primarily driven by changes in sediment silt content. Short term changes in light and/or nutrient availability had little impact on community composition. In this open estuarine system the use of diatom indices to infer past water quality must take into account the sediment silt content in their interpretations.  相似文献   

Preface: Probing the Sun Inside and Out     

Louise Harra  Deborah Baker  Rachel Howe  John Leibacher  Lidia van Driel-Gesztelyi 《Solar physics》2015,290(11):3091-3094

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Observations of the Ca <Emphasis Type="SmallCaps">ii</Emphasis> IR Triplet in High Luminosity Quasars: Exploring the Sample     

Mary Loli Martínez-Aldama  Paola Marziani  Deborah Dultzin  Jack W. Sulentic  Alessandro Bressan  Yang Chen  Giovanna M. Stirpe 《Journal of Astrophysics and Astronomy》2015,36(4)

We present a new spectroscopic sample of 11 quasars at intermediate redshift observed with the Infrared Spectrometer and Array Camera (ISAAC) on the ESO Very Large Telescope (VLT), covering O i λ8446 and the Ca ii triplet 8498, 8542, 8662. The new observations – that supplement the sample presented by Martínez-Aldama et al. (2015) – allow us to confirm the constraints on physical conditions and location of the region emitting the low ionization lines, as well as the relation between Ca ii and Fe ii.  相似文献   

Opportunities and challenges in rebuilding tornado-impacted Greensburg,Kansas as “stronger,better, and greener”     

Bimal Kanti Paul  Deborah Che 《GeoJournal》2011,76(1):93-108

A May 2007 tornado destroyed 95% of aging, declining Greensburg, Kansas. The city took the opportunity to build back “stronger, better, and greener,” enforcing upgraded codes, requiring city-owned buildings to meet LEED Platinum level standards, and recommending energy-efficiency housing in a new Sustainable Comprehensive Plan. Using information collected from surveys of Greensburg tornado survivors, interviews, and publications, we examined the housing-related recovery, including the emergency provision of temporary shelter and rebuilding permanently. Although temporary shelter kept residents nearby for rebuilding, given the gap between insurance policy limits on the aging housing stock and rebuilding costs, housing affordability is a critical issue in Greensburg’s recovery. Local, state, and federal support have made construction of municipal buildings at LEED Platinum level and some affordable and green housing projects possible. However, far greater public and private sector funding for affordable workforce housing, in conjunction with broader economic and job development, is needed.  相似文献   

The Bioavailability of Effluent-derived Organic Nitrogen along an Estuarine Salinity Gradient     

Katherine C. Filippino  Margaret R. Mulholland  Peter W. Bernhardt  George E. Boneillo  Ryan E. Morse  Matthew Semcheski  Harold Marshall  Nancy G. Love  Quinn Roberts  Deborah A. Bronk 《Estuaries and Coasts》2011,34(2):269-280

Total maximum daily loads for nitrogen (N) are currently being established for the Chesapeake Bay watershed. While we know inorganic N is bioavailable in the environment and therefore its input contributes to cultural eutrophication, the bioavailability of organic N is unclear. Using bioassay experiments, we examined the impact of effluent-derived organic nitrogen (EON) from wastewater treatment plants on natural water samples collected along an estuarine/salinity gradient within the lower Chesapeake Bay watershed. All of the inorganic N and between 31% and 96% of the EON was removed during biotic bioassays within the first 2 days. Further, there was substantial abiotic reactivity of effluent N when it was added to natural water samples. Results demonstrate that organic and inorganic N in effluent is removed to support the growth of microbial communities. These are the first results aimed at assessing the reactivity of EON in natural waters along an estuarine/salinity gradient.  相似文献   

Editorial     

Phil Potts  Michel Grégoire  Bill McDonough  Thomas Meisel  Jon Woodhead 《Geostandards and Geoanalytical Research》2011,35(1):5-5

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Using Multiple Methods to Understand the Nature of Relationships in Social Networks     

Vanessa M. Adams  Katie Moon  Jorge G. Álvarez-Romero  Örjan Bodin  Michaela Spencer  Deborah Blackman 《社会与自然资源》2018,31(7):755-772

Effective natural resource management (NRM) often depends on collaboration through formal and informal relationships. Social network analysis (SNA) provides a framework for studying social relationships; however, a deeper understanding of the nature of these relationships is often missing. By integrating multiple analytical methods (including SNA, evidence ratings, and perception matrices), we were able to investigate the nature of relationships in NRM social networks across five service types (e.g., technical advice, on-ground support) in our case study region, Daly catchment Australia. Only one service type was rated as highly associated with free choice in establishing relationships: technical advice/knowledge. Beneficial characteristics of NRM organizations, such as collaborative and transparent, were associated with the presence of freely chosen relationships between organizations. Our results suggest a need to improve our understanding of organizational roles and characteristics, in particular for use in applied NRM contexts, such as network weaving or disseminating information.  相似文献   

Subjectivity,Power, and the IRB     

Deborah G. Martin  Joshua Inwood 《The Professional geographer》2013,65(1):7-15

A substantial literature in social sciences, including law and society, examines the intersections of research ethics and institutional review board (IRB) frameworks. Although geographers have engaged this literature, we argue that further involvement in ethical and regulatory discussions will advance opportunities for better understanding and negotiating the complex subjectivities produced in the IRB structure. Drawing on illustrative experiences of researchers, we focus specifically on the institutions convening IRBs, the researchers, and the human “subjects” produced in the IRB process. We conclude with a call for greater open discussion of the power dynamics, subjectivities, and challenges of formal ethical research structures.  相似文献   

A search for temporal variability in the surface chemistry of the icy Galilean satellites     

Deborah Domingue  Amanda Hendrix 《Icarus》2005,173(1):50-65

The purpose of this study was to determine if any temporal variability in the broadband UV spectral properties of the icy Galilean satellites exists, and if so, to characterize its spatial distribution as a function of longitude in order to attempt to correlate any temporal changes with satellite surface interactions with the space environment. The temporal time period examined is between 1978-1984 (referred to as the 1980s data) and those from 1995-1996 (referred to as the 1990s data). The plausible temporal characteristics detected appear to vary from one satellite to the next. For Europa possible temporal variations are concentrated on the leading, anti-jovian quadrant. Example broadband UV spectra show Europa's spectral slope decreases (and darkens) with time on the leading and anti-jovian hemispheres, but remains essentially constant with time on the trailing hemisphere. The data quality does not support any definitive temporal changes for Ganymede. Possible temporal changes seen in the Callisto data set are concentrated on the jovian hemisphere. Example broadband UV spectra for Callisto show no definitive change in slope with time. The hypothesis is that these temporal differences in UV spectral properties are caused by variations in the surface ice chemistry due to temporal variability in the space environment. It is postulated that the UV spectral changes suggested for Europa may be linked to changes in H₂O₂ concentrations, whereas the changes on Callisto may be linked to variability in SO₂ concentration.  相似文献   

A Study of Governance Arrangements for Land Use and Natural Resource Management Planning in Cape York Peninsula     

Ruth Potts  Karen Vella  Allan Dale  Neil Sipe 《The Australian geographer》2015,46(3):389-409

Complex intersecting social, economic and environmental dilemmas in Australia's Cape York Peninsula present a number of challenges for planners seeking to develop and implement land use and natural resource management (NRM) plans. There have been five different attempts at land use and NRM planning in Cape York Peninsula over the last 20 years. These processes have (to greater or lesser extents) failed to deliver community-owned and government-supported plans to guide development and/or the management of the region's natural resources. The region is remote, sparsely populated, and home to a significant Indigenous population. Much of the contestation within the region surrounds the access, use and ownership of the region's internationally valuable natural resources. This paper reviews, from the literature, the relevancy and applicability of criteria for best practice planning and governance. A range of identified best practice governance and planning principles are applied to assess the governance arrangements for planning in the Peninsula. The paper finds that decision-making arrangements for land use and NRM planning in the Peninsula are still in their infancy and are inadequate to support effective outcomes. The paper concludes that broader attention to best practice principles in governance for planning is needed to improve planning outcomes.  相似文献