The Use of Network Analysis to Compare the Nitrogen Cycles of Three Salt Marsh Zones Experiencing Relative Sea-level Rise

The Use of Network Analysis to Compare the Nitrogen Cycles of Three Salt Marsh Zones Experiencing Relative Sea-level Rise PDF Author: Cassondra R. Thomas
Publisher:
ISBN:
Category : Nitrogen cycle
Languages : en
Pages : 418

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The Use of Network Analysis to Compare the Nitrogen Cycles of Three Salt Marsh Zones Experiencing Relative Sea-level Rise

The Use of Network Analysis to Compare the Nitrogen Cycles of Three Salt Marsh Zones Experiencing Relative Sea-level Rise PDF Author: Cassondra R. Thomas
Publisher:
ISBN:
Category : Nitrogen cycle
Languages : en
Pages : 418

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Concepts and Controversies in Tidal Marsh Ecology

Concepts and Controversies in Tidal Marsh Ecology PDF Author: M.P. Weinstein
Publisher: Springer Science & Business Media
ISBN: 0792360192
Category : Nature
Languages : en
Pages : 862

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Tidal salt marshes are viewed as critical habitats for the production of fish and shellfish. As a result, considerable legislation has been promulgated to conserve and protect these habitats, and much of it is in effect today. The relatively young science of ecological engineering has also emerged, and there are now attempts to reverse centuries-old losses by encouraging sound wetland restoration practices. Today, tens of thousands of hectares of degraded or isolated coastal wetlands are being restored worldwide. Whether restored wetlands reach functional equivalency to `natural' systems is a subject of heated debate. Equally debatable is the paradigm that depicts tidal salt marshes as the `great engine' that drives much of the secondary production in coastal waters. This view was questioned in the early 1980s by investigators who noted that total carbon export, on the order of 100 to 200 g m-2 y-1 was of much lower magnitude than originally thought. These authors also recognized that some marshes were either net importers of carbon, or showed no net exchange. Thus, the notion of `outwelling' has become but a single element in an evolving view of marsh function and the link between primary and secondary production. The `revisionist' movement was launched in 1979 when stable isotopic ratios of macrophytes and animal tissues were found to be `mismatched'. Some eighteen years later, the view of marsh function is still undergoing additional modification, and we are slowly unraveling the complexities of biogeochemical cycles, nutrient exchange, and the links between primary producers and the marsh/estuary fauna. Yet, since Teal's seminal paper nearly forty years ago, we are not much closer to understanding how marshes work. If anything, we have learned that the story is far more complicated than originally thought. Despite more than four decades of intense research, we do not yet know how salt marshes function as essential habitat, nor do we know the relative contributions to secondary production, both in situ or in the open waters of the estuary. The theme of this Symposium was to review the status of salt marsh research and revisit the existing paradigm(s) for salt marsh function. Challenge questions were designed to meet the controversy head on: Do marshes support the production of marine transient species? If so, how? Are any of these species marsh obligates? How much of the production takes place in situ versus in open waters of the estuary/coastal zone? Sessions were devoted to reviews of landmark studies, or current findings that advance our knowledge of salt marsh function. A day was also devoted to ecological engineering and wetland restoration papers addressing state-of-the-art methodology and specific case histories. Several challenge papers arguing for and against our ability to restore functional salt marshes led off each session. This volume is intended to serve as a synthesis of our current understanding of the ecological role of salt marshes, and will, it is hoped, pave the way for a new generation of research.

Ecological Society of America ... Annual Meeting Abstracts

Ecological Society of America ... Annual Meeting Abstracts PDF Author: Ecological Society of America. Meeting
Publisher:
ISBN:
Category : Ecology
Languages : en
Pages : 836

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Official Meeting Program

Official Meeting Program PDF Author: Ecological Society of America. Meeting
Publisher:
ISBN:
Category : Ecology
Languages : en
Pages : 608

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Salt Marsh Nitrogen Analysis

Salt Marsh Nitrogen Analysis PDF Author: Thomas M. Leschine
Publisher:
ISBN:
Category : Biological productivity
Languages : en
Pages : 64

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Book Description
A five compartment schematic model of the flow of nitrogen through Great Sippewissett Marsh is presented. Flows are described in terms of annual inputs, outputs and intercompartmental transfers of nitrogen. The nitrogen in all forms occurring in the marsh is considered, though dissolved organic nitrogen is disaggregated from the total flow. A computer aided input - output analysis is performed on the model to assess the degree to which nitrogen inputs to the marsh surface are linked to nitrogen outputs in the form of net growth in marsh shellfish. In this way the effects of both direct and indirect flows linking the two compartments involved are considered. The analysis is done to assess the likelihood that a large scale application of fertilizer to the marsh surface will signjficantly enhance shellfish growth in marsh tidal creeks. While no definitive answer to this question can be given, it is argued that the present level of understanding of the marsh nitrogen cycle does not support an expectation that shellfish growth will be enhanced. This argument is supported by a comparative analysis which shows a strong likelihood that Spartina growth is enhanced by fertilization, an effect which has already been observed.

Nitrogen in the Marine Environment

Nitrogen in the Marine Environment PDF Author: Edward J. Carpenter
Publisher: Elsevier
ISBN: 1483288293
Category : Science
Languages : en
Pages : 919

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Book Description
Nitrogen in the Marine Environment provides information pertinent to the many aspects of the nitrogen cycle. This book presents the advances in ocean productivity research, with emphasis on the role of microbes in nitrogen transformations with excursions to higher trophic levels. Organized into 24 chapters, this book begins with an overview of the abundance and distribution of the various forms of nitrogen in a number of estuaries. This text then provides a comparison of the nitrogen cycling of various ecosystems within the marine environment. Other chapters consider chemical distributions and methodology as an aid to those entering the field. This book discusses as well the enzymology of the initial steps of inorganic nitrogen assimilation. The final chapter deals with the philosophy and application of modeling as an investigative method in basic research on nitrogen dynamics in coastal and open-ocean marine environments. This book is a valuable resource for plant biochemists, microbiologists, aquatic ecologists, and bacteriologists.

Nitrogen Cycling in the North Atlantic Ocean and its Watersheds

Nitrogen Cycling in the North Atlantic Ocean and its Watersheds PDF Author: Robert W. Howarth
Publisher: Springer Science & Business Media
ISBN: 9400917767
Category : Science
Languages : en
Pages : 300

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Book Description
Human activity has dramatically altered the global nitrogen cycle in recent decades. These changes are not evenly distributed around the world; rather, they are greatest in regions of significant industrial and agricultural activity, as the synthesis and use of inorganic fertilizers, cultivation of legumes, burning of fossil fuels, and the simple act of concentrating humans and animals in dense populations all lead to the release of excess, reactive forms of nitrogen into the environment. In part because reactive nitrogen is frequently a limiting nutrient in many terrestrial and aquatic systems, an excess can lead to a variety of adverse effects on both environmental and human health. The North Atlantic Ocean and its contributing watersheds constitute a region which has seen perhaps the greatest increase in anthropogenically-derived nitrogen. In May of 1994, the International Scope Nitrogen Project, with funding from the Andrew Mellon Foundation, the United Nations Environment Program, and the World Meteorological Organization, sponsored a workshop held on Block Island, RI, USA, entitled `Nitrogen Dynamics of the North Atlantic Basin'. More than 50 scientists from 12 different countries convened with a unique set of goals: an integrated and comprehensive estimate of the current nitrogen cycle of the ocean, coastal systems, and contributing watersheds of the North Atlantic region; an analysis of human-induced changes to those cycles; and an assessment of the current and future effects of human-induced changes to nitrogen cycling throughout the globe.

The Effects of Relative Sea Level Rise on a Virginia Salt Marsh

The Effects of Relative Sea Level Rise on a Virginia Salt Marsh PDF Author: Karen A. Slattery
Publisher:
ISBN:
Category : Sea level
Languages : en
Pages : 184

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Assessment of Nitrogen Cycle Processes by Evaluation of Redox Potentials in Sea Water and Soil at the Santa Ana River Salt Marsh Restoration Project

Assessment of Nitrogen Cycle Processes by Evaluation of Redox Potentials in Sea Water and Soil at the Santa Ana River Salt Marsh Restoration Project PDF Author: Timothy Wayne Tucker
Publisher:
ISBN:
Category : Nitrogen compounds
Languages : en
Pages : 196

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Nitrogen Cycling in Coastal Marine Environments

Nitrogen Cycling in Coastal Marine Environments PDF Author: T. Henry Blackburn
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 488

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Nitrogen discharge to the coastal environment has been increasing, posing the threat of accelerated eutrofication. Considerable research has been conducted in recent years to examine the impact of the nitrogen loading in coastal ecosystems. Based on proceedings from a SCOPE symposium held at the University of Aarhus in July of 1985, this volume covers a variety of up-to-date developments in research on nitrogen cycling in coastal marine environments. Topics include the role of nitrogen in algal productivity, regeneration of nutrients in the water column and the sediments, and the flow of nitrogen in coastal ecosystems.