[PDF] Organic Matter Cycling And Nutrient Dynamics In Marine Sediments eBook

Author : Angelos K. Hannides
Publisher :
Page : 878 pages
File Size : 34,80 MB
Release : 2008
Category : Biogeochemical cycles
ISBN :

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This dissertation explores two recently recognized pathways of organic matter supply to marine sediments and their impact on sedimentary biogeochemistry: The entrapment and decomposition of particulate organic matter in permeable sediments and the resulting nutrient dynamics were investigated with a specially designed experimental laboratory microcosm that allows permeable sediment incubation under controlled physical forcing. Microcosm generated enhanced solute transport rates were roughly proportional to sediment column permeability. Comparison with field observations revealed that the enhanced transport rates induced by the experimental conditions were lower than those observed in the field, and this was also reflected in the enhanced buildup of pore water nutrients relative to concentrations in field sediments. Particulate organic matter and nutrient enrichment experiments, conducted with the microcosm, demonstrated the rapid uptake of both particles and solutes by the permeable sediment column under physical forcing, the rapid decomposition of the removed particles, and the lack of regenerated nutrient build-up. Nutrient enrichment experiments with sediment plug chambers demonstrated the rapid uptake and retention of nutrients by surface permeable sediments, as well as the loss of nitrogen though benthic denitrification in sediment grain microzones. The processing of large organic matter packages on the deepsea floor by deep-sea communities was investigated using natural and experimental whale, kelp and wood falls in the California Borderland Basins region, focusing on their quality and its impact on sedimentary organic enrichment and redox shifts. Labile organic material generated by the processing of whale falls and kelp falls generated substantial pore water sulfide levels in impacted sediment, despite a small organic enrichment signal. In contrast, wood derived material input did not result in sulfidic conditions, despite generating very high organic enrichment in impacted sediments, due to its refractory nature. A constructed model incorporating metazoan processing and dispersal of fragmented material revealed that whale fall processing is characterized by higher rates of tissue removal, organic carbon release, and carbon sedimentation rates than wood fall processing. However, organic carbon release rates, when normalized to fall weight, are similar between the two types of falls, due to differences in their carbon content and in absorption rates during metazoan ingestion.

Author : J. Gray
Publisher : Springer Science & Business Media
Page : 243 pages
File Size : 15,91 MB
Release : 2012-12-06
Category : Science
ISBN : 9401146497

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Oceanographic discontinuities (e. g. frontal systems, upwelling areas, ice edges) are often areas of enhanced biological productivity. Considerable research on the physics and biology of the physical boundaries defining these discontinues has been accomplished (see [I D. The interface between water and sediment is the largest physical boundary in the ocean, but has not received a proportionate degree of attention. The purpose of the Nato Advanced Research Workshop (ARW) was to focus on soft-sediment systems by identifying deficiencies in our knowledge of these systems and defining key issues in the management of coastal sedimentary habitats. Marine sediments play important roles in the marine ecosystem and the biosphere. They provide food and habitat for many marine organisms, some of which are commercially important. More importantly from a global perspective, marine sediments also provide "ecosystem goods and services" [2J. Organic matter from primary production in the water column and contaminants scavenged by particles accumulate in sediments where their fate is determined by sediment processes such as bioturbation and biogeochemical cycling. Nutrients are regenerated and contaminants degraded in sediments. Under some conditions, carbon accumulates in coastal and shelf sediments and may by removed from the carbon cycle for millions of years, having a potentially significant impact on global climate change. Sediments also protect coasts. The economic value of services provided by coastal areas has recently been estimated to be on the order of $12,568 9 10 y" [3J, far in excess of the global GNP.

Author : M. J. R. Fasham
Publisher : Springer Science & Business Media
Page : 722 pages
File Size : 12,66 MB
Release : 2013-03-09
Category : Science
ISBN : 1475703872

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The impetus for the conference held at Bombannes, France in May, 1982 arose out of a Scientific Committee on Oceanic Research (SCOR) Working Group on "Mathematical Models in Biological Oceanography". This group was chaired by K.H. Mann and held two meetings in 1977 and 1979. At both meetings it was felt that, although reductionist modelling of marine ecosystems had achieved some successes, the future progress lay in the development of holistic ecosystem models. The members of the group (K.H. Mann, T. Platt, J.M. Colebrook, D.F. Smith, M.J.R. Fasham, J. Field, G. Radach, R.E. Ulanowicz and F. Wulff) produced a critical review of reductionist and holistic models which was published by the Unesco Press (Platt, Mann and Ulanowicz, 1981). One of the conclusions of this review was that, whether holistic or reductionist models are preferred, it is critically important to increase the scientific effort in the measurement of physiological rates for the computation of ecological fluxes. The Working Group therefore recommended that an international meeting should be organized which would attempt to bring together theoretical ecologists and biological oceanographers to assess the present and future capability for measuring ecological fluxes and incorporating these data into models. An approach was made to the Marine Sciences Panel of the NATO Science Committee who expressed an interest in funding such a meeting. They awarded a planning grant and a planning group was formed consisting of M.J.R. Fasham, M.V. Angel, T. Platt, R.E.

Author : Kon-Kee Liu
Publisher : Springer Science & Business Media
Page : 757 pages
File Size : 30,28 MB
Release : 2010-02-11
Category : Science
ISBN : 3540927352

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This book is a product of the joint JGOFS (Joint Global Ocean Flux Study)/LOICZ (Land–Ocean Interactions in the Coastal Zone) Continental Margins Task Team which was established to facilitate continental margins research in the two projects. It contains signi cant information on the physical, biogeochemical, and ecosystems of continental margins nationally and regionally and provides a very valuable synthesis of this information and the physical, biogeochemical and ecosystem processes which occur on continental margins. The publication of this book is timely as it provides a very strong foundation for the development of the joint IMBER (Integrated Marine Biogeochemistry and Ecosystems Research)/LOICZ Science Plan and Implemen- tion Strategy for biogeochemical and ecosystems research in the continental margins and the impacts of global change on these systems. This initiative will move forward integrated biogeochemical and ecosystems research in the continental margins. We thank all the contributors to this volume and especially Kon-Kee Liu who has dedicated a great deal of time to ensuring a high-quality book is published. IMBER Scienti c Steering Committee Julie Hall LOICZ Scienti c Steering Committee Jozef Pacyna v 1 Preface In general, interfaces between the Earth’s larger material reservoirs (i. e. , the land, atmosphere, ocean, and sediments) are important in the control of the biogeoche- cal dynamics and cycling of the major bio-essential elements, including carbon (C), nitrogen (N), phosphorus (P), sulfur (S), and silicon (Si), found in organic matter and the inorganic skeletons, shells, and tests of benthic and marine organisms.

Author : Edward J. Carpenter
Publisher : Elsevier
Page : 919 pages
File Size : 38,53 MB
Release : 2013-10-22
Category : Science
ISBN : 1483288293

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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.

Author : Richard G. Zepp
Publisher : John Wiley & Sons
Page : 364 pages
File Size : 11,36 MB
Release : 1995-07-11
Category : Science
ISBN : 9780471954637

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Nonliving organic matter (NLOM) comprises the bulk of the organic carbon stored in the terrestrial biosphere and a major part of the organic carbon in the sea. Organic substances, which include litter, marine detritus, dissolved organic matter, and soil organic matter, have diverse effects on the Earth's biogeochemical processes and serve as a major reservoir of biospheric carbon, which can be transformed to carbon dioxide, methane, and other "greenhouse" gases. Given this broad spectrum of effects, efforts to adapt to or perhaps benefit from global change require a better understanding and an ability to predict the role of NLOM in the global environment. The overall objective of this volume is to provide experimental and modeling strategies for the assessment of the sensitivity of the global carbon cycle to changes in nonliving organic pools in terrestrial and aquatic ecosystems. The discussions in this volume consider how best to characterize and quantify pools and fluxes of NLOM, the role of NLOM cycling on a global scale, human and climatic perturbations of interactions between NLOM and nutrients, and biological, chemical, and physical processes that control the production and degradation of NLOM, with an emphasis on processes that affect the persistence of NLOM in the environment. One of the most unique aspects of this volume is that it represents extensive exchanges between leading international scientists from both aquatic and terrestrial backgrounds. It will be of particular interest to organic geochemists, microbiologists, ecologists, soil scientists, agricultural scientists, marine chemists, limnologists, and modelers. Goal of this Dahlem Workshop: to devise experimental and modeling strategies for assessment of the sensitivity of the global carbon cycle to changes in nonliving organic pools.

Author :
Publisher : American Geophysical Union
Page : 391 pages
File Size : 18,12 MB
Release : 2005-01-14
Category : Science
ISBN : 087590274X

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Marine sediments support complex interactions between macro-and microorganisms that have global implications for carbon and nutrient cycles. What is the state of the science on such interactions from coastal and estuarine environments to the deep sea? How does such knowledge effect environmental management? And what does future research hold in store for scientists, engineers, resource managers, and educators?Interactions between Macro- and Microorganisms in Marine Sediments responds to these questions, and more, by focusing on:? Interactions between plants, microorganisms, and marine sediment? Interactions between animals, microorganisms, and marine sediment? Interactions between macro- and microorganisms and the structuring of benthic communities? Impact of macrobenthic activity on microbially-mediated geochemical cycles in sediments? Conceptual and numeric models of diagenesis that incorporate interactions between macro- and microorganismsHere is an authoritative overview of the research, experimentation and modeling approaches now in use in our rapidly evolving understanding of life in marine sediments.

Author : Thibault Datry
Publisher : Academic Press
Page : 624 pages
File Size : 49,4 MB
Release : 2017-07-11
Category : Science
ISBN : 0128039043

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Intermittent Rivers and Ephemeral Streams: Ecology and Management takes an internationally broad approach, seeking to compare and contrast findings across multiple continents, climates, flow regimes, and land uses to provide a complete and integrated perspective on the ecology of these ecosystems. Coupled with this, users will find a discussion of management approaches applicable in different regions that are illustrated with relevant case studies. In a readable and technically accurate style, the book utilizes logically framed chapters authored by experts in the field, allowing managers and policymakers to readily grasp ecological concepts and their application to specific situations. Provides up-to-date reviews of research findings and management strategies using international examples Explores themes and parallels across diverse sub-disciplines in ecology and water resource management utilizing a multidisciplinary and integrative approach Reveals the relevance of this scientific understanding to managers and policymakers

Author : Stuart Findlay
Publisher : Academic Press
Page : 534 pages
File Size : 21,86 MB
Release : 2003
Category : Nature
ISBN : 0122563719

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Overviews of the source, supply and variability of DOM, surveys of the processes that mediate inputs to microbial food webs, and syntheses consolidating research findings provide a comprehensive review of what is known of DOM in freshwater. This book will be important to anyone interested in understanding the fundamental factors associated with DOM that control aquatic ecosystems."--BOOK JACKET.

Author : N. Handa
Publisher : Springer Science & Business Media
Page : 561 pages
File Size : 31,17 MB
Release : 2013-03-09
Category : Science
ISBN : 9401713197

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Over the past decade the scientific activities of the Joint Global Ocean Flux Study (JGOFS), which focuses on the role of the oceans in controlling climate change via the transport and storage of greenhouse gases and organic matter, have led to an increased interest in the study of the biogeochemistry of organic matter. There is also a growing interest in global climate fluctuations. This, and the need for a precise assessment of the dynamics of carbon and other bio-elements, has led to a demand for an improved understanding of biogeochemical processes and the chemical characteristics of both particulate and dissolved organic matter in the ocean. A large amount of proxy data has been published describing the changes of the oceanic environment, but qualitative and quantitative estimates of the vertical flux of (proxy) organic compounds have not been well documented. There is thus an urgent need to pursue this line of study and, to this end, this book starts with several papers dealing with the primary production of organic matter in the upper ocean. Thereafter, the book goes on to follow the flux and characterization of particulate organic matter, discussed in relation to the primary production in the euphotic zone and resuspension in the deep waters, including the vertical flux of proxy organic compounds. It goes on to explain the decomposition and transformation of organic matter in the ocean environment due to photochemical and biological agents, and the reactivity of bulk and specific organic compounds, including the air-sea interaction of biogenic gases. The 22 papers in the book reflect the interests of JGOFS and will thus serve as a valuable reference source for future biogeochemical investigations of both bio-elements and organic matter in seawater, clarifying the role of the ocean in global climate change.