Download or read book Mineralization of Soil Nitrogen in a Managed Forest in California written by Douglas William Frazer and published by . This book was released on 1985 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Publications Quarterly List written by and published by . This book was released on 1990 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nitrogen Mineralization Responses to Bearclover Incorporation in Forest Soils written by Beverly Anne Gularte and published by . This book was released on 1993 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Soil Science written by and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil is formed from physical and chemical weathering of rocks - processes described historically because they involve eons of time-by glaciation and by wind and water transport of soil materials, later deposited in deltas and loessial planes. Soil undergoes further transformations over time and provides a habitat for biological life and a base for the development of civilizations. Soil is dynamic -always changing as a result of the forces of nature and particularly by human influences. The soil has been studied as long as history has been documented. Numerous references to soil are found in historical writings such as Aristotle (384-322 B. c. ), Theophrastus (372-286 B. c. ), Cato the Elder (234-149 B. C. ) and Varro (116-27 B. c. ). Some of the earliest historical references have to do with erosional forces of wind and water. The study of soils today has taken on increased importance because a rapidly expanding population is placing demands on the soil never before experienced. This has led to an increase in land degradation and desertification. Desertifica tion is largely synonymous with land degradation but in an arid land context. Deterioration of soil resources is largely human induced. Poverty, ignorance, and greed are the indirect causes of desertification. The direct cause is mismanage ment of the land by practices such as overgrazing, tree removal, improper tillage, poorly designed and managed water distribution systems, and overexploitation.
Download or read book Non linear Nitrogen Dynamics and Calcium Depletion Along a Temperate Forest Soil Nitrogen Gradient written by Emily R. Sinkhorn and published by . This book was released on 2008 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding how N availability influences base cation stores is critical for long-term ecosystem sustainability. Indices of nitrogen (N) availability and the distribution of nutrients in plant biomass, soil, and soil water were examined across ten young, unpolluted Douglas-fir (Pseudotsuga menziesii) stands in the Oregon Coast Range spanning a three-fold soil N gradient (0-10 cm: 0.21 - 0.69% N, 0-100 cm: 9.2 - 28.8 Mg N . ha−1 but having similar stand age and sandstone parent material. [delta]15N in foliage and forest floor increased across the gradient and approached the isotopic signature of the atmosphere at high soil N stands, suggesting that variation in N accumulation across sites is related to historic site occupancy by N2−fixing red alder (Alnus rubra). Although no longer present on these sites, red alder stands can add 100-200 kg N ha−1 yr−1to an ecosystem for decades, a significantly higher N input than precipitation (0.65 kg N ha−1yr−1). Annual net N mineralization and litterfall N return displayed non-linear relationships with soil N, increasing initially, and then decreasing at more N-rich sites. In contrast, nitrate leaching from deep soils increased linearly across the soil N gradient and ranged from 0.074 to 30 kg N . ha−1yr−1). Nitrogen availability was negatively correlated with indices of Ca availability. Soil exchangeable Ca, Mg, and K pools to 1 m depth were negatively related to nitrate losses across sites. Calcium was the only base cation that decreased in both plant and soil pools across the soil N gradient, and a greater proportion of total available ecosystem Ca was sequestered in plant biomass at high N, low Ca sites. The preferential storage of Ca in aboveground biomass at high N and low Ca sites, while critical for sustaining plant productivity, may also predispose forests to Ca depletion in areas managed for intensive biomass removal. Our work supports a hierarchical model of coupled N-Ca cycles across gradients of soil N enrichment, with microbial production of mobile nitrate leading to depletion of readily available Ca at the ecosystem scale, and plant sequestration promoting Ca conservation as Ca supply diminishes. Long-term N enrichment of temperate forest soils appears capable of sustaining an open N cycle and key symptoms of N saturation for multiple decades after the cessation of elevated N inputs.
Download or read book Soil Enzymes written by Roger George Burns and published by . This book was released on 1978 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: History of abiontic soil ensyme research; Origin and range of enzymes in soil; kinetics and consecutive reactions of soil enzymes; Soil polysaccharidases: activity and agricultural importance; Urease activity in soils; Soil phosphatase and sulphatase; Interactions between agrochemicals and soil enzymes; Enzyme activity in soil: some theoretical and practical considerations; Methodology of soil enzyme measurement and extraction.
Download or read book General Technical Report PSW written by and published by . This book was released on 1978 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optimizing Nitrogen Management in Food and Energy Production and Environmental Protection written by J. Galloway and published by CRC Press. This book was released on 2002-01-01 with total page 1042 pages. Available in PDF, EPUB and Kindle. Book excerpt: The production of food and energy interfere with the natural nitrogen cycle of the earth. Many of these changes are beneficial, while others are detrimental to societies and the environment. The changing nature of nitrogen in the global environment crosses scientific disciplines, geographical boundaries and political divisions and challenges the creative minds of natural and social scientists, economists, engineers, business leaders and planners. The papers in this book give readers a panoramic view of the changing nature of reactive nitrogen in the global environment, enabling them to make better choices about nitrogen management in food production and consumption, energy production and use, and environmental protection.
Download or read book Methods of Soil Analysis Part 2 written by Richard W. Weaver and published by ACSESS. This book was released on 1994 with total page 1164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil sampling for microbiological analysis; Statistical treatment of microbial data; Soil sterilization; Soil water potencial; Most probable number counts; Light microscopic methods for studying soil microorganisms; Viruses; Recovery and enumeration of viable bacteria; Coliform bacteria; Autotrophic nitrifying bacteria; Free-living dinitrogen-fixing bacteria; Legume nodule symbionts; Anaerobic bacteria and processes; Denitrifiers; Actiomycetes; Frankia and the actinorhizal symbiosis; Filamentous fungi; Vesicular-arbuscular mycorrhizal fungi; Isolation of microorganisms producting antibiotics; Microbiological procedures for biodegradation research; Algae and cyanobacteria; Marking soil bacteria with lacZY; Detection of specific DNA sequences in environmental sample via polymerase chaim reaction; Isolation and purification of bacterial DNA from soil; Microbial biomass; Soil enzymes; Carbon mineralization; Isotopic methods for the study of soil organic matter dynamics ; Practical considerations in the use of nitrogen tracers in agricultural and environmental research; Nitrogen availability; Nitrogen mineralization, immobilization, and nitrification; Dinitrogen fixation; Measuring denitrification in the field; Sulfur oxidation and reduction in soils; Iron and manganese oxidation and reduction.
Download or read book Carbon and Nitrogen in Forest Ecosystems Series I written by Yowhan Son and published by MDPI. This book was released on 2021-01-20 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the differences in carbon and nitrogen distribution and cycling both spatially and temporally using various approaches is essential in forest ecosystems. In addition, the influence of biotic and abiotic factors as well as natural and artificial disturbances on carbon and nitrogen cycling need to first be understood before drawing their implications to forest management practices. This Special Issue aims to understand carbon and nitrogen distribution and cycling in forest ecosystems for ecosystem-based forest management under different natural and artificial disturbances.
Download or read book Linking Carbon Nitrogen and Calcium Cycling in Northeastern U S Forests written by April Marin Melvin and published by . This book was released on 2012 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon (C), nitrogen (N), and calcium (Ca) cycling in forest ecosystems is controlled largely by the recycling of organic matter by biota and by the balance of new inputs and losses. In the northeastern U.S., the availability of these elements has been dramatically altered by human activities. Acid deposition has increased N inputs and caused declines in soil Ca concentrations. Concurrently, atmospheric carbon dioxide concentrations are rising. My dissertation research focused on understanding how individual tree species influence ecosystem C, N, and Ca cycling, and how increasing soil Ca by liming affects C and N pools, fluxes, and dissolved organic matter retention. In chapter 1, I show how Norway spruce, red oak, and sugar maple planted in a common garden influence soil C, N, and Ca pools. Norway spruce had the largest C and N stocks in the forest floor and upper mineral soils. No differences among species were observed in soil exchangeable Ca availability. Red oak plots displayed the highest foliar litter lignin concentrations, the shortest residence time for C and N in the forest floor, and the highest earthworm densities. This suggests that leaf litter recalcitrance is not the dominant driver of decomposition in this forest and that other factors, such as the presence of earthworms, can influence organic matter turnover in ways that are unexpected when only considering litter chemistry. In chapters 2 and 3, I discuss the long-term effects of liming on ecosystem C and N dynamics. Twenty years after lime addition, there was no evidence of a tree response. Within the forest floor, C and N stocks in limed soils were double that found in controls. I observed reductions in both soil basal respiration and net N mineralization, indicating that liming has altered C and N cycling within this ecosystem. I also investigated how soil exchangeable Ca concentrations influence dissolved organic C and N retention. Soils higher in exchangeable Ca tended to release less C and N, suggesting that liming may facilitate Ca-organic matter bridging, thereby reducing C and N losses from the upper mineral soils.
Download or read book Soil Carbon Mineralization and Nitrogen Transformations in Soils Previously Amended with Sewage Sludge written by Michael Boyle and published by . This book was released on 1986 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Symposium on Dynamics and Management of Mediterranean Type Ecosystems written by and published by . This book was released on 1982 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings Symposium On Sustainable Management Of Hemlock Ecosystems in Eastern North America June 22 24 1999 Durham New General T written by and published by . This book was released on 1980 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book From Fires to Oceans Dynamics of Fire Derived Organic Matter in Terrestrial and Aquatic Ecosystems written by Samuel Abiven and published by Frontiers Media SA. This book was released on 2019-05-09 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fire-derived organic matter, also known as pyrogenic carbon (PyC), is ubiquitous on Earth. It can be found in soils, sediments, water and air. In this wide range of environments, fire-derived organic matter, represents a key component of the organic matter pool, and, in many cases, the largest identifiable group of organic compounds. PyC is also one of the most persistent organic matter fractions in the ecosystems, and its study is, therefore, particularly relevant for the global carbon cycle. From its production during vegetation fires to its transfer into soils, sediments and waters, PyC goes through different transformations, both abiotic and biotic. Contrary to early assumptions, PyC is not inert and interacts strongly with the environment: evidence of microbial decomposition, oxidation patterns and interactions with minerals have been described in different matrices. PyC travels across these different environments and it is modified chemically and physically, but remains persistent. This Research Topic explores important questions in our understanding of fire-derived organic matter, from the characterization and quantification of PyC components, to the transformation and mobilization processes taking place on terrestrial and aquatic ecosystems. The studies compiled here provide novel and, often, unexpected results. They all answer some of the questions posed and, more importantly, provide scope for many more.
Download or read book Annotated Bibliography of Publications on Watershed Management and Ecological Studies at Coweeta Hydrologic Laboratory 1934 1994 written by and published by . This book was released on 1994 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book General Technical Report PNW GTR written by and published by . This book was released on 1999 with total page 1016 pages. Available in PDF, EPUB and Kindle. Book excerpt:
