Nitrogen Dynamics Through the Forest Floor of Two Interior Alaska Black Spruce Ecosystems PDF Download

Author: Michael G. Weber
Publisher:
ISBN:
Category : Black spruce
Languages : en
Pages : 278

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Author: M. G. Weber
Publisher:
ISBN:
Category :
Languages : en
Pages : 9

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Author: W.H. Schlesinger
Publisher: Academic Press
ISBN: 0123858747
Category : Nature
Languages : en
Pages : 689

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For the past 4 billion years, the chemistry of the Earth's surface, where all life exists, has changed remarkably. Historically, these changes have occurred slowly enough to allow life to adapt and evolve. In more recent times, the chemistry of the Earth is being altered at a staggering rate, fueled by industrialization and an ever-growing human population. Human activities, from the rapid consumption of resources to the destruction of the rainforests and the expansion of smog-covered cities, are all leading to rapid changes in the basic chemistry of the Earth. The Third Edition of Biogeochemistry considers the effects of life on the Earth's chemistry on a global level. This expansive text employs current technology to help students extrapolate small-scale examples to the global level, and also discusses the instrumentation being used by NASA and its role in studies of global change. With the Earth's changing chemistry as the focus, this text pulls together the many disparate fields that are encompassed by the broad reach of biogeochemistry. With extensive cross-referencing of chapters, figures, and tables, and an interdisciplinary coverage of the topic at hand, this text will provide an excellent framework for courses examining global change and environmental chemistry, and will also be a useful self-study guide. Emphasizes the effects of life on the basic chemistry of the atmosphere, the soils, and seawaters of the EarthCalculates and compares the effects of industrial emissions, land clearing, agriculture, and rising population on Earth's chemistrySynthesizes the global cycles of carbon, nitrogen, phosphorous, and sulfur, and suggests the best current budgets for atmospheric gases such as ammonia, nitrous oxide, dimethyl sulfide, and carbonyl sulfideIncludes an extensive review and up-to-date synthesis of the current literature on the Earth's biogeochemistry.

Author: United States. Environmental Protection Agency
Publisher:
ISBN:
Category : Alaska
Languages : en
Pages : 204

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Author:
Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 714

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Author: Teresa Nettleton Hollingsworth
Publisher:
ISBN:
Category : Black spruce
Languages : en
Pages : 326

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"The boreal forest is the largest terrestrial ecosystem in North America, one of the least disturbed by humans, and most disturbed by fire. This combination makes it an ideal system to explore the environmental controls over species composition, the relative importance of abiotic factors and floristic composition in governing ecosystem processes, and the importance of legacy effects at a large regional spatial scale. In the boreal region of interior Alaska, Picea mariana (black spruce) is the predominant tree species and spans a wide range of habitats, including north-facing slopes with permafrost, lowland bogs, and high dry ridge-tops. This research uses a combination of site description and analysis from both locally near Fairbanks (54) and across a large region and number of sites (146) to answer questions about the regional variability and biodiversity of the black spruce forest type. Based on the relationships between species composition and environmental factors, topography and elevation were the most important gradients explaining species composition locally in the Fairbanks region, and mineral soil pH was the overriding environmental gradient across interior Alaska. To describe the floristic variability, I separated the black spruce forest type into three floristically-based community types and five community subtypes. Variability in ecosystem properties among black spruce stands was as large as that documented previously among all forest types in the central interior of Alaska. The variability in plant community composition was at least as effective as environmental or abiotic factors and stand characteristics as a predictor of soil C pools in the black spruce forest type of interior Alaska. The variability in species composition at the community subtype-level was related to a combination of environmental factors and fire history. Together, these results provide a foundation for future work in black spruce ecosystems of interior Alaska, and contribute to our understanding of the regional variability and biodiversity of the black spruce forest type"--Leaves iii-iv.

Author: Jason Gene Vogel
Publisher:
ISBN:
Category : Black spruce
Languages : en
Pages : 356

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"Climate warming in high latitudes is expected to alter the carbon cycle of the boreal forest. Warming will likely increase the rate of organic matter decomposition and microbial respiration. Faster organic matter decomposition should increase plant available nutrients and stimulate plant growth. I examined these predicted relationships between C cycle components in three similar black spruce forests (Picea mariana [Mill] B.S.P) near Fairbanks, Alaska, that differed in soil environment and in-situ decomposition. As predicted, greater in-situ decomposition rates corresponded to greater microbial respiration and black spruce aboveground growth. However root and soil respiration were both greater at the site where decomposition was slowest, indicating greater C allocation to root processes with slower decomposition. It is unclear what environmental factor controls spruce allocation. Low temperature or moisture could cause spruce to increase belowground allocation because slower decomposition leads to low N availability, but foliar N concentration was similar across sites and root N concentration greater at the slow decomposition site. The foliar isotopic composition of 13C indicated soil moisture was lower at the site with greater root and soil respiration. From a literature review of mature black spruce forests, it appears drier (e.g. Alaska) regions of the boreal forest have greater soil respiration because of greater black spruce C allocation belowground. Organic matter characteristics identified with pyrolysis gas chromatography-mass spectrometry correlated with microbial processes, but organic matter chemistry less influenced C and N mineralization than did temperature. Also, differences among sites in C and net N mineralization rates were few and difficult to explain from soil characteristics. Warming had a greater influence on C and N mineralization than the mediatory effect of soil organic matter chemistry. In this study, spruce root C allocation varied more among the three stands than other ecosystem components of C cycling. Spruce root growth most affected the annual C balance by controlling forest floor C accumulation, which was remarkably sensitive to root severing. Predicting the response of black spruce to climate change will require an understanding of how spruce C allocation responds to available moisture and soil temperature"--Leaves iii-iv.

Author: Sarah J. Woodin
Publisher: Cambridge University Press
ISBN: 9780521839983
Category : Nature
Languages : en
Pages : 304

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Once thought of as a pristine environment, it is now all too apparent that the Arctic is a sink for pollutants transported northwards over long distances in the atmosphere and oceans, and is also likely to be subject to major climate change as a result of global warming. Many ecologists are currently seeking to further our understanding of how arctic ecosystems function, and to detect and predict anthropogenic changes which may occur within them. This book, resulting from a British Ecological Society Special Symposium, addresses these issues.

Author: Gordon Bonan
Publisher: Cambridge University Press
ISBN: 1107043778
Category : Gardening
Languages : en
Pages : 743

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The thoroughly updated new edition of Gordon Bonan's comprehensive textbook on terrestrial ecosystems and climate change, for advanced students and researchers.

Author:
Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 830

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