Download or read book Nitrogen Trace Gas Emissions from Soils Spanning a 4 5 Million Year Chronosequence in Hawaiian Montane Rainforest written by Ralph Hayward Riley and published by . This book was released on 1992 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 1993-05 with total page 766 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigating Feedbacks from Soil Trace Gas Fluxes of Carbon Dioxide and Nitrogen Oxides to Anthropogenic Nitrogen Deposition and Climate Change written by Jennifer Rae Eberwein and published by . This book was released on 2016 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: Human alteration of the carbon (C) and nitrogen (N) cycles is having profound detrimental impacts on natural systems. This dissertation research focused on investigating soil feedbacks to multiple anthropogenic drivers to explore unifying mechanisms applicable to global biogeochemical modeling. In Chapter 1 and 2, I investigate how changes in C, N, and temperature regulate soil CO2 production (Rsoil) through changes to the Michaelis-Menten parameters (i.e. Vmax and kM) using soils from three contrasting ecosystems in southern California in Chapter 1 and in subtropical evergreen forests of southern China in Chapter 2. Overall, the response of Rsoil to N addition was generally dependent on C:N stoichiometry, consistent with predictions from the dynamic microbial carbon-use efficiency hypothesis. Furthermore, I show the first empirical results from whole soil measurements demonstrating temperature sensitivity of both Vmax and kM, showing strong support for substrate regulation of Rsoil temperature sensitivity across diverse soils. Results from Chapters 1 and 2 demonstrate great potential for Michaelis-Menten kinetics in describing Rsoil responses to N and temperature, with implications for understanding microbial physiology and broad applicability to global biogeochemical modeling. Chapter 3 extends this research by exploring N trace gas emissions and evaluating variation in the microbial community composition along an N deposition gradient in the Colorado Desert. Results from Chapter 3 present soil N fluxes that were considerably higher than expected, demonstrating a need for greater appreciation of arid systems in global N budgets. While short term effects of experimental N addition resulted in inconsistent responses in the microbial community composition, long-term N deposition resulted in a distinct differentiation of the microbial community, with possible implications for N cycling. Microbial communities associated with nitrification, identified from 16S rRNA sequencing and qPCR of amoA, demonstrate a shift from archaeal dominance at the low deposition site to more bacterial dominance at the high deposition site. Overall, results from this dissertation contribute to mechanistic understanding of soil feedbacks to climate change and nitrogen deposition, which is necessary for predicting future changes and developing strategies for mitigation of anthropogenic global change drivers.
Download or read book Compilation of a Global N 2 O Emission Inventory for Tropical Rainforest Soils Using a Detailed Biogeochemical Model written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrous oxide (N2O) is a potent trace gas contributing to approximately 6% to the observed anthropogenic global warming. Soils have been identified to be the major source of atmospheric N2O and tropical rainforest soils are thought to account for the largest part. Furthermore, various studies have shown that the magnitude of N2O emissions from tropical rainforest soil is highly variable on spatial and temporal scales. Detailed, process-based models coupled to Geographic Information Systems (GIS) are considered promising tools for the calculation of N2O emission inventories. This methodology explicitly accounts for the governing microbial processes as well as the environmental controls. Moreover, mechanistic biogeochemical models operating in daily time-steps (e.g. ForestDNDC-tropica) have been shown to capture the observed intra- and inter-annual variations of N2O emissions. However, detailed N2O emission datasets are required for model calibration and testing, but are currently few in numbers. In this study an automated measurement system was used to derive detailed datasets of N2O, methane (CH4) and carbon dioxide (CO2) soil-atmosphere exchange and important environmental parameters from tropical rainforest soils in Kenya and Southwest China. Distinct differences were identified in the magnitude of the C and N soil-atmosphere exchange at the investigated sites and forest types. However, common features such as N2O pulse emissions after dry season or the pronounced soil moisture dependency of N2O emissions were observed at both sites. The derived datasets are unique for these tropical regions as so far no information about the source strength of these regions was available and, for the first time, the N2O, CH4 and CO2 soil-atmosphere exchange was recorded in sub-daily resolution. The datasets were utilized in conjunction with available high-resolution datasets from Australian rainforests for the re-calibration of the ForestDNDC-tropica model using a multi-site, par.
Download or read book Hydrological and Biogeochemical Controls on Nitrogen Losses from Tropical Forests written by Kathleen Ann Lohse and published by . This book was released on 2002 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Soil Nitrogen Oxide and Carbon Dioxide Emissions from a Tropical Lowland and Montane Forest Exposed to Elevated Nitrogen Input written by Birgit Köhler and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sources and Controls of Reactive Nitrogen Gas Emissions from a Mojave Desert Ecosystem written by Carmody K. McCalley and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This body of work considerably expands our understanding of gaseous nitrogen (N) loss dynamics in arid ecosystems, a process that directly affects longterm N bioavailability and the release of chemically important gas species into the atmosphere. Chapter one focuses on identifying controls over biological sources of reactive N gas emissions, especially the pulse of NO and NH3 that occurs following precipitation. This research shows a two-step response of reactive N gas emissions to pulsed water additions. First, there is a large transient NH3 pulse. Second, biological activity is stimulated leading to NO production by nitrifying bacteria. Results indicate that biological sources of NO and NH3 efflux respond primarily to the addition of water; however, fluxes are modulated by temperature and nutrient constraints on microbial activity. Chapter two explores the role of non-biological processes in reactive N gas emissions from desert soils. Combination of laboratory and field measurements show that abiotic reactions are a key component of N loss from desert soils, both under dry conditions and during post-wetting periods. It is hypothesized that during the summer, extreme surface soil temperatures caused by direct exposure to incoming solar radiation result in thermal decomposition of N-containing compounds, yielding elevated rates of reactive N gas efflux. Chapter three focuses on the effects of elevated CO2 on soil fluxes of reactive N gases. Under soil conditions optimal for biological activity, long-term fumigation with elevated CO2 reduces reactive N gas losses in the islands of fertility created by the dominant shrub Larea tridentata. These results provide supporting evidence that elevated CO2 alters soil N dynamics in arid ecosystems, including increased N immobilization and decreased N mineralization and nitrification. Chapter four provides a robust estimate of annual reactive N gas emissions for a Mojave Desert ecosystem, accounting for daily, seasonal and yearly variation in environmental conditions. This annual estimate of 0.1 to 0.6 kg N ha-1 y-1 includes considerable variation, reflecting inter-annual variability in summer precipitation and growing season moisture conditions. These results demonstrate the strong impact that alterations in precipitation patterns under future climate scenarios will have on N dynamics in water limited ecosystems.
Download or read book Differential Effect of Carbon Sources on Nitrogen Transformation in Hawaiian Soils written by Anand Swaroop Agarwal and published by . This book was released on 1972 with total page 537 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Trace Gas Fluxes and Belowground Carbon Allocation in Tropical Montane Forest Soils of Southern Ecuador written by Katrin Wolf and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biochar for Environmental Management written by Johannes Lehmann and published by Routledge. This book was released on 2012-05-16 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biochar is the carbon-rich product when biomass (such as wood, manure or crop residues) is heated in a closed container with little or no available air. It can be used to improve agriculture and the environment in several ways, and its stability in soil and superior nutrient-retention properties make it an ideal soil amendment to increase crop yields. In addition to this, biochar sequestration, in combination with sustainable biomass production, can be carbon-negative and therefore used to actively remove carbon dioxide from the atmosphere, with major implications for mitigation of climate change. Biochar production can also be combined with bioenergy production through the use of the gases that are given off in the pyrolysis process. This book is the first to synthesize the expanding research literature on this topic. The book's interdisciplinary approach, which covers engineering, environmental sciences, agricultural sciences, economics and policy, is a vital tool at this stage of biochar technology development. This comprehensive overview of current knowledge will be of interest to advanced students, researchers and professionals in a wide range of disciplines.
Download or read book Principles of Terrestrial Ecosystem Ecology written by F Stuart Chapin III and published by Springer Science & Business Media. This book was released on 2006-04-10 with total page 449 pages. Available in PDF, EPUB and Kindle. Book excerpt: Features review questions at the end of each chapter; Includes suggestions for recommended reading; Provides a glossary of ecological terms; Has a wide audience as a textbook for advanced undergraduate students, graduate students and as a reference for practicing scientists from a wide array of disciplines
Download or read book Carbon Sequestration in Forest Ecosystems written by Klaus Lorenz and published by Springer Science & Business Media. This book was released on 2009-11-25 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon Sequestration in Forest Ecosystems is a comprehensive book describing the basic processes of carbon dynamics in forest ecosystems, their contribution to carbon sequestration and implications for mitigating abrupt climate change. This book provides the information on processes, factors and causes influencing carbon sequestration in forest ecosystems. Drawing upon most up-to-date references, this book summarizes the current understanding of carbon sequestration processes in forest ecosystems while identifying knowledge gaps for future research, Thus, this book is a valuable knowledge source for students, scientists, forest managers and policy makers.
Download or read book Global Change and the Earth System written by Will Steffen and published by Springer Science & Business Media. This book was released on 2005-12-29 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: Global Change and the Earth System describes what is known about the Earth system and the impact of changes caused by humans. It considers the consequences of these changes with respect to the stability of the Earth system and the well-being of humankind; as well as exploring future paths towards Earth-system science in support of global sustainability. The results presented here are based on 10 years of research on global change by many of the world's most eminent scholars. This valuable volume achieves a new level of integration and interdisciplinarity in treating global change.
Download or read book Mangrove Ecosystems A Global Biogeographic Perspective written by Victor H. Rivera-Monroy and published by Springer. This book was released on 2017-11-03 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a comprehensive overview and analysis of mangrove ecological processes, structure, and function at the local, biogeographic, and global scales and how these properties interact to provide key ecosystem services to society. The analysis is based on an international collaborative effort that focuses on regions and countries holding the largest mangrove resources and encompasses the major biogeographic and socio-economic settings of mangrove distribution. Given the economic and ecological importance of mangrove wetlands at the global scale, the chapters aim to integrate ecological and socio-economic perspectives on mangrove function and management using a system-level hierarchical analysis framework. The book explores the nexus between mangrove ecology and the capacity for ecosystem services, with an emphasis on thresholds, multiple stressors, and local conditions that determine this capacity. The interdisciplinary approach and illustrative study cases included in the book will provide valuable resources in data, information, and knowledge about the current status of one of the most productive coastal ecosystem in the world.
Download or read book Fundamentals of Geomorphology written by Richard John Huggett and published by Routledge. This book was released on 2011-03-15 with total page 909 pages. Available in PDF, EPUB and Kindle. Book excerpt: This extensively revised, restructured, and updated edition continues to present an engaging and comprehensive introduction to the subject, exploring the world’s landforms from a broad systems perspective. It covers the basics of Earth surface forms and processes, while reflecting on the latest developments in the field. Fundamentals of Geomorphology begins with a consideration of the nature of geomorphology, process and form, history, and geomorphic systems, and moves on to discuss: structure: structural landforms associated with plate tectonics and those associated with volcanoes, impact craters, and folds, faults, and joints process and form: landforms resulting from, or influenced by, the exogenic agencies of weathering, running water, flowing ice and meltwater, ground ice and frost, the wind, and the sea; landforms developed on limestone; and landscape evolution, a discussion of ancient landforms, including palaeosurfaces, stagnant landscape features, and evolutionary aspects of landscape change. This third edition has been fully updated to include a clearer initial explanation of the nature of geomorphology, of land surface process and form, and of land-surface change over different timescales. The text has been restructured to incorporate information on geomorphic materials and processes at more suitable points in the book. Finally, historical geomorphology has been integrated throughout the text to reflect the importance of history in all aspects of geomorphology. Fundamentals of Geomorphology provides a stimulating and innovative perspective on the key topics and debates within the field of geomorphology. Written in an accessible and lively manner, it includes guides to further reading, chapter summaries, and an extensive glossary of key terms. The book is also illustrated throughout with over 200 informative diagrams and attractive photographs, all in colour.
Download or read book The Soil Resource written by Hans Jenny and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: change is simply described by the rate of income and rate of loss. Our home's energy budget, our firm's inventory, our nation's debt, and humanity's numbers all have accounts that change at rates that are equal to the inputs minus the outputs. Jenny's "system view" of the soil was carried into the fertile fields of Midwestern American prairies from the laboratories of Switzerland in the late 1920s. Jenny's rate equations provided the other paradigm or world view that, I recall, brought us to the threshold of systems ecology as it later evolved in the second half of the twentieth century. As if world renown in the specialties of pedology and soil chemistry were not enough for one lifetime, excerpts below remind us that Hans Jenny has also been a perceptive outdoor field ecologist since his early Alpine expeditions with Braun Blanquet in the mid 1920s. Jenny's ecosystem studies in the pygmy forest, a further classic example of a soil-plant system "run down" over hundreds of thousands of years since its origin, continue to occupy some of the vigorous retirement time near his farm in Mendocino County. But each specific, quantitative case study, and each research area conserved (with additional hard work) for further study by future generations, fits into Jenny's coherent world view. It is that view, and its legacies of discovery and of tangible landscape preserves, which we are privileged to share with their originator in this volume.
Download or read book Radon A Tracer for Geological Geophysical and Geochemical Studies written by Mark Baskaran and published by Springer. This book was released on 2016-08-11 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews all the major research accomplishments and summarizes the different applications of radon. It serves as a solid reference book for researchers who are interested in the U-series radionuclides and noble gases as tracers and chronometers. Radon has been widely utilized as a powerful tracer to quantify a number of processes that include gas exchange rates between air and water, submarine groundwater discharge in coastal waters, water exchange between rivers and lakes, ocean circulation, hydrocarbon and uranium exploration. It is also used as an atmospheric tracer for the identification and quantification of air masses and as a tool for earthquake prediction, etc. A significant portion of the book presents state-of-the knowledge on indoor-radon-related health issues. Applications of the decay-series of Rn-222 are presented in a chapter. It serves as a reference and a state-of-the-art resource for researchers who want to learn the different applications of radon in Earth systems.
