Download or read book Response of Soil Microbial Communities and Nitrogen Cycling Processes to Changes in Vegetation Inputs written by Elizabeth Ann Brewer and published by . This book was released on 2010 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: Changes in the type and amount of plant inputs can occur gradually, as with succession, or rapidly, as with harvesting or wildfire. With global change it is anticipated that both gradual and immediate scenarios will occur at increasing frequency. Changes in vegetation inputs alter the quality and quantity of soil organic matter inputs, thus influencing the composition of soil microbial communities and the nutrient cycles they mediate. Understanding the relationship of soil organic matter inputs on soil microbial communities and nutrient cycles will be beneficial in predicting responses to changes in vegetation inputs. During the last 100-150 years, the vegetation of the Rio Grande Plains of the United States has been shifting from grasslands/savannas to woodlands as the result of encroachment of N2-fixing trees and their associated plant communities. The structure and diversity of soil microbial communities were examined under woody species and remnant grasslands. In addition, relationships between soil microbial communities and soil physical and chemical characteristics were explored. Soil microbial communities differed in soils under N2-fixing trees and associated vegetation compared to remnant grasslands. Differences in both fungal and bacterial communities were anticipated with vegetation shifts; however, only fungal communities correlated with vegetation, whereas bacterial communities were influenced by spatial heterogeneity. Soil microbial N cycling was investigated in long-term (>10 years) organic matter manipulations in an old-growth forest, dominated by large Pseudotsuga menziesii (Mirb.) Franco (Douglas-fir). The objectives of this research were to: 1) determine if long-term organic matter manipulations in old-growth forests altered microbial N cycling, 2) determine the contribution of litter to N cycling, and 3) determine if litter quality (low C/N red alder and high C/N Douglas-fir) affected the contribution of litter-derived N to N transformations. Long-term organic matter manipulations were found to affect microbial C and N cycling, but to a lesser degree than anticipated. After 10 years of organic matter exclusions and additions, microbial communities in all treatments remained N limited, although N limitation was less severe in organic matter exclusion treatments. Adding leached litter to control and organic matter exclusion soils initially altered N processes but differences dissipated during a 151-day incubation. Litter quality had little impact on the N cycling and litter made modest contributions to N mineralization and nitrification. The exclusion of organic matter altered the functionality of the microbial community to access litter-derived N. Both the gradual establishment of woody clusters on grassland and abrupt manipulations of old-growth vegetation inputs elicited responses in microbial communities and N cycling. Although some responses were subtle, they nonetheless support the responsiveness and importance of microbial communities to soil processes. Understanding feedbacks among plant inputs, microbial communities and nutrient cycles will aid in predicting microbial, ecosystem, and global responses to vegetation changes.

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 Carbon and Nitrogen Cycling in Soil written by Rahul Datta and published by Springer Nature. This book was released on 2019-08-24 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several textbooks and edited volumes are currently available on general soil fertility but‚ to date‚ none have been dedicated to the study of “Sustainable Carbon and Nitrogen Cycling in Soil.” Yet this aspect is extremely important, considering the fact that the soil, as the ‘epidermis of the Earth’ (geodermis)‚ is a major component of the terrestrial biosphere. This book addresses virtually every aspect of C and N cycling, including: general concepts on the diversity of microorganisms and management practices for soil, the function of soil’s structure-function-ecosystem, the evolving role of C and N, cutting-edge methods used in soil microbial ecological studies, rhizosphere microflora, the role of organic matter (OM) in agricultural productivity, C and N transformation in soil, biological nitrogen fixation (BNF) and its genetics, plant-growth-promoting rhizobacteria (PGPRs), PGPRs and their role in sustainable agriculture, organic agriculture, etc. The book’s main objectives are: (1) to explain in detail the role of C and N cycling in sustaining agricultural productivity and its importance to sustainable soil management; (2) to show readers how to restore soil health with C and N; and (3) to help them understand the matching of C and N cycling rules from a climatic perspective. Given its scope, the book offers a valuable resource for educators, researchers, and policymakers, as well as undergraduate and graduate students of soil science, soil microbiology, agronomy, ecology, and the environmental sciences. Gathering cutting-edge contributions from internationally respected researchers, it offers authoritative content on a broad range of topics, which is supplemented by a wealth of data, tables, figures, and photographs. Moreover, it provides a roadmap for sustainable approaches to food and nutritional security, and to soil sustainability in agricultural systems, based on C and N cycling in soil systems.

Download or read book The European Nitrogen Assessment written by Mark A. Sutton and published by Cambridge University Press. This book was released on 2011-04-14 with total page 665 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presenting the first continental-scale assessment of reactive nitrogen in the environment, this book sets the related environmental problems in context by providing a multidisciplinary introduction to the nitrogen cycle processes. Issues of upscaling from farm plot and city to national and continental scales are addressed in detail with emphasis on opportunities for better management at local to global levels. The five key societal threats posed by reactive nitrogen are assessed, providing a framework for joined-up management of the nitrogen cycle in Europe, including the first cost-benefit analysis for different reactive nitrogen forms and future scenarios. Incorporating comprehensive maps, a handy technical synopsis and a summary for policy makers, this landmark volume is an essential reference for academic researchers across a wide range of disciplines, as well as stakeholders and policy makers. It is also a valuable tool in communicating the key environmental issues and future challenges to the wider public.

Download or read book Plant soil microbial Nitrogen Cycling Across Contrasting Organic Farms in an Intensively managed Agricultural Landscape written by Timothy Michael Bowles and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: How farming systems supply sufficient nitrogen (N) for high yields but with reduced N losses is a central challenge for reducing the tradeoffs often associated with N cycling in agriculture. This dissertation consists of three studies that assess how variability in organic farms across an agricultural landscape may yield insights for improving N cycling and for evaluating novel indicators of N availability. Pulses of N are common in agricultural systems and often result in N losses if N is not quickly captured by plants or soil microbes. But understanding of how root behavioral responses and microbial N dynamics interact following soil N pulses remains limited, especially in soil under field conditions relevant to actual agroecosystem processes. The first study examined rhizosphere responses to a soil N pulse in an organic farm soil. A novel combination of molecular and 15N isotopic techniques was used to investigate the response of tomato (Solanum lycopersicum L.) roots and soil N cycling to a pulse of inorganic N in an undisturbed soil patch on an organic farm. Tomato roots rapidly responded to and exploited the N pulse via upregulation of key N metabolism genes that comprise the core physiological response of roots to patchy soil N availability. The transient root gene expression response underscored the sensitivity of root N uptake to local N availability. Strong root activity limited accumulation of soil nitrate (NO3−) despite high rates of gross nitrification and allowed roots to out-compete soil microbes for uptake of the inorganic N pulse, even on the short time scale of a few days. Root expression of genes such as cytosolic glutamine synthetase, a key gene in root N assimilation, could serve as a "plant's eye view" of N availability when plant-soil N cycling is rapid, complementing more typical measures of N availability like soil inorganic N pools and bioassays of N mineralization potential. Much of the research geared toward improving N cycling takes place at research stations with fixed management factors and limited variation in soil characteristics. Better understanding of how the plant-soil-microbe interactions that underpin N availability, potential for N loss, and yields vary across working farms would help reveal how to simultaneously achieve high provisioning (yields) and regulating (low potential for N loss) ecosystem services in heterogeneous landscapes. A landscape approach was thus used in the second and third studies to assess crop yields, plant-soil N cycling, root gene expression, and soil microbial community activity and composition over the course of a tomato growing season on working organic farms in Yolo County, California, USA. The 13 selected fields were representative of organic tomato production in the local landscape and spanned a three-fold range of soil carbon (C) and N but had similar soil types, texture, and pH. Yields ranged from 22.9 to 120.1 Mg ha−1 with a mean similar to the county average (86.1 Mg ha−1), which included mostly conventionally-grown tomatoes. Substantial variability in soil inorganic N concentrations, tomato N, and root gene expression indicated a range of possible tradeoffs between yields and potential for N losses across the fields. Soil enzyme activities reflected distinct metabolic capacity in each field, such that soil C-cycling enzyme potential activities increased with inorganic N availability while those of soil N-cycling enzymes increased with soil C availability. Compared to potential enzyme activity, there was less variation in soil microbial community composition, likely reflecting the history of high soil disturbance and low ecological complexity in this landscape. The variation in potential activity of soil enzymes across the organic fields thus may be due to high plasticity of the resident microbial community to environmental conditions. Those fields in the landscape that showed evidence of tightly-coupled plant-soil N cycling, a desirable scenario in which high crop yields are supported by adequate N availability but low potential for N loss, had the highest total and labile soil C and N and received diverse types of organic matter inputs with a range of N availability. In these fields, elevated expression of cytosolic glutamine synthetase in roots (as evaluated in the first study), confirmed that plant N assimilation was high even when soil inorganic N pools were low. The on-farm approach provided a wide range of farming practices and soil characteristics to reveal how microbially-derived ecosystem functions can be effectively manipulated to enhance nutrient cycling capacity. Novel combinations of N cycling indicators (i.e. inorganic N along with soil microbial activity and root gene expression for N assimilation) would support adaptive management for improved N cycling on organic as well as conventional farms, and could overcome the uncertainty of managing N inputs accurately, especially when plant-soil N cycling is rapid.

Download or read book The Microbial Regulation of Global Biogeochemical Cycles written by Johannes Rousk and published by Frontiers E-books. This book was released on 2014-10-17 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Global biogeochemical cycles of carbon and nutrients are increasingly affected by human activities. So far, modeling has been central for our understanding of how this will affect ecosystem functioning and the biogeochemical cycling of carbon and nutrients. These models have been forced to adopt a reductive approach built on the flow of carbon and nutrients between pools that are difficult or even impossible to verify with empirical evidence. Furthermore, while some of these models include the response in physiology, ecology and biogeography of primary producers to environmental change, the microbial part of the ecosystem is generally poorly represented or lacking altogether. The principal pool of carbon and nutrients in soil is the organic matter. The turnover of this reservoir is governed by microorganisms that act as catalytic converters of environmental conditions into biogeochemical cycling of carbon and nutrients. The dependency of this conversion activity on individual environmental conditions such as pH, moisture and temperature has been frequently studied. On the contrary, only rarely have the microorganisms involved in carrying out the processes been identified, and one of the biggest challenges for advancing our understanding of biogeochemical processes is to identify the microorganisms carrying out a specific set of metabolic processes and how they partition their carbon and nutrient use. We also need to identify the factors governing these activities and if they result in feedback mechanisms that alter the growth, activity and interaction between primary producers and microorganisms. By determining how different groups of microorganisms respond to individual environmental conditions by allocating carbon and nutrients to production of biomass, CO2 and other products, a mechanistic as well as quantitative understanding of formation and decomposition of organic matter, and the production and consumption of greenhouse gases, can be achieved. In this Research Topic, supported by the Swedish research councils' programme "Biodiversity and Ecosystem Services in a Changing Landscape" (BECC), we intend to promote this alternative framework to address how cycling of carbon and nutrients will be altered in a changing environment from the first-principle mechanisms that drive them – namely the ecology, physiology and biogeography of microorganisms – and on up to emerging global biogeochemical patterns. This novel and unconventional approach has the potential to generate fresh insights that can open up new horizons and stimulate rapid conceptual development in our basic understanding of the regulating factors for global biogeochemical cycles. The vision for the research topic is to facilitate such progress by bringing together leading scientists as proponents of several disciplines. By bridging Microbial Ecology and Biogeochemistry, connecting microbial activities at the micro-scale to carbon fluxes at the ecosystem-scale, and linking above- and belowground ecosystem functioning, we can leap forward from the current understanding of the global biogeochemical cycles.

Download or read book Microbial Biomass A Paradigm Shift In Terrestrial Biogeochemistry written by Kevin Russel Tate and published by World Scientific. This book was released on 2017-02-08 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microbial Biomass informs readers of the ongoing global revolution in understanding soil and ecosystem microbial processes. The first paper on the subject was written by David Jenkinson in 1966, and here new insights and expansions are given on the fascinating world of soil microbial processes. In terms of contemporary issues, it also serves to support urgent efforts to sustainably manage land to feed a growing world population without compromising the environment. It presents new methods of investigation which are leading to more sustainable management of ecosystems, and improved understanding of ecosystem changes in an increasingly warmer world.The book approaches the topic by looking at the emergence of our understanding of soil biological processes, and begins by tracing the conception and first measurement of soil microbial biomass. Following this, changes in ecosystems, and in natural ecosystem processes are discussed in relation to land management issues and global change. Microbial biomass and its diversity are recognized as key factors in finding solutions for more sustainable land and ecosystem management, aided by new molecular and other tools. Information from the use of these tools is now being incorporated into emerging microbial-explicit predictive models, to help us study changes in earth system processes.Perfect for use in research and practice, this book is written for undergraduate and graduate students, researchers and professionals of agronomy, chemistry, geology, physical geography, ecology, biology, microbiology, silviculture and soil science.

Download or read book Carbon mediated Ecological and Physiological Controls on Nitrogen Cycling Across Agricultural Landscapes written by Andrew James Curtright and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The sustainable intensification of agriculture relies on the efficient use of ecosystem services, particularly those provided by the microbial community. Managing for these ecosystem services can improve plant yields and reduce off-site impacts. For instance, increasing plant diversity is linked to positive effects on yield, and these beneficial effects are often mediated by the microbial community and the nutrient transformations it carries out. My dissertation has aimed to elucidate the mechanisms by which plant diversity improves agricultural production. In particular, I have focused on how changes to the amount and diversity of carbon (C) inputs affects soil microorganisms involved in the nitrogen (N) cycle. My work spans multiple scales of observation: from a global meta-analysis to mechanistic studies utilizing denitrification as a model system.In a global meta-analysis, I found that increasing plant diversity through intercropping yields a net increase in extracellular enzyme activity. This effect varied by plant species and soil type suggesting that increases in the quality of nutrient inputs mediates these positive effects on microbial activity. Then, I looked at how intercropping cover crops into corn affects soil nutrient pools and microbial activities in a field experiment. No effect of interseeding cover crops into corn was found on soil nutrient pools or microbial activities. However, by analyzing differences in relationships between nutrient pools and microbial activities at two locations throughout Michigan, I was able to describe how the availability of dissolved organic C (DOC) drives differences in microbial N-cycling processes. I then investigated how C availability drives activity in microbial hotspots within the soil by comparing differences in denitrification potential in bulk soil versus the rhizospheres of corn and interseeded cover crops. Here, I found that denitrification rates were increased in the rhizospheres of all plant types, and this effect varied depending on the species of plant. I was able to further differentiate the impact of DOC and microbial biomass C on the rhizosphere effect and found that C availability was the primary driver of differences in denitrification rates between rhizospheres. Since plants provide many different forms of C to soil microbes, it is important to understand how the chemistry of C inputs affects microbial activity. I used a series of C-substrate additions to determine how C chemistry affects denitrifiers. I found that amino acids and organic acids tended to stimulate the most nitrous oxide (N2O) production and reduction. Although management and site affected overall rates of denitrification, C-utilization patterns of microbes were mostly similar between locations. To identify the mechanisms responsible for these effects, I performed a final experiment to track how denitrifiers utilized different C compounds. The C substrates that stimulated the most complete reduce of N2O also were utilized with the lowest C-use efficiency (CUE). This suggests possible trade-offs between N2O reduction and CUE, with important implications for how to manage microbial communities.Overall, my work demonstrates that land management can impact microbial community activity by influencing the identity of soil C inputs. While the importance of increasing soil C inputs has been known, this dissertation supports the notion that the chemical identity of C inputs can exert significant controls on microbial activity. Moreover, by comparing microbial traits I highlight the importance of trade-offs in how microbially mediated C- and N cycling are coupled.

Download or read book Soil Taxonomy written by and published by . This book was released on 1975 with total page 772 pages. Available in PDF, EPUB and Kindle. Book excerpt: Resource added for the Landscape Horticulture Technician program 100014.

Download or read book The Effects of Changing Precipitation Patterns on Soil Microbial Communities and Nitrogen Cycling in the New Jersey Pinelands written by William Joel Landesman and published by . This book was released on 2009 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: I studied the potential effects of a change in the amount, frequency and timing of precipitation on soil microbes and nitrogen cycling in the New Jersey Pinelands. I performed a two year field manipulation of precipitation amount and measured the response of the microbial community, potential net nitrogen mineralization and amino acid production. I found that soil microbes were not affected by rain exclusion or a doubling of rainfall. Nematode densities, but not community composition, were sensitive to precipitation amount. A large accumulation of ammonium in drought plots suggested sustained microbial activity under extreme drought conditions. I observed small changes in potential net nitrogen mineralization due to the effects of soil moisture on diffusion and immobilization. I measured the short-term response of the microbial community to a rewetting of dry soil and found a very rapid (three hour) change in the microbial community. The accumulation of ammonium within drought plots appears to have suppressed fungal biomass following the rewetting event. In a two year winter study, I found no long-term effect of supplemental winter rainfall on the soil microbial community. Elevated winter precipitation prevented ammonium accumulation, presumably by protecting plant roots from freeze damage. I found that supplemental watering insulates soil microbes from cold stress over the short-term (days), but that mid-winter declines in biomass due to cold soil. These experiments demonstrate that soil microbial communities in Pinelands soils are highly tolerant of abiotic stressors such as drought, upshock stress and soil freezing. Recovery from these disturbances is extremely rapid, occurring on the scale of hours to days. I conclude that changing precipitation patterns will not have a direct, long-term effect on soil microbial communities. Changes in precipitation patterns are more likely to alter nitrogen cycling rates via the influence on nitrogen diffusion and plant and microbial uptake. Furthermore, precipitation-induced changes in nematode densities may have important implications for nitrogen cycling in the New Jersey Pinelands.

Download or read book Soil and Microbial Response to Manipulated Precipitation and Land Management written by Tiffany LaRose Carter and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Microorganisms play a vital role in maintaining plant and soil health. Within soils, microorganisms are responsible for nutrient cycling and organic matter decomposition. Because soil microbes are sensitive to environmental conditions, they are early indicators of changes in soil health. Soil microbes depend heavily on moisture and substrate availability for growth and survival. Limitation of either factor can alter the survival rates and microbial community function. The objectives of this study were to understand better soil microbial responses to manipulated precipitation and land management by (i) assessing the microbial community composition and soil properties after over 25 years of irrigation in annually burned native prairie; (ii) assessing the effect of long-term irrigation on microbial community respiration response to moisture and substrate addition; and (iii) assessing the soil microbial community and soil structure of degraded agricultural soil under conventional tillage sorghum (CT), no-till sorghum (NT), and replanted big bluestem (RP). The first two objectives were based on a long-term study in a tallgrass prairie where ambient and irrigated transects have been maintained for 25 years. Soil samples were collected four times per year and assessed for soil chemical properties and microbial community structure. The third study used a long-term (17-y) study of ecosystems (replanted big bluestem, and no-till and tilled sorghum). Soil C and N, aggregate structure and microbial community structure were measured. Contrary to previous research, long-term irrigation did not significantly impact the overall microbial community; however, there was a seasonal effect on the microbial community. Fungal PLFA biomarkers increased at the end of each growing season. Because greater soil water content and carbon inputs are known to contribute to fungal dominance, this increase can generally be attributed to seasonal plant growth cycles. Bacterial PLFA biomarkers peaked during the middle of the plant growth cycle indicating the influence of plant inputs on microbial growth. Microbial response to water and glucose addition in the laboratory was significant, indicating a historic effect of irrigation on community composition. For the third objective, soil macroaggregate formation was directly correlated to changes in land management. Macroaggregate fractions were greatest in replanted big bluestem soils, followed by no till and conventional till grain sorghum. No significant differences in soil organic carbon or total nitrogen were observed between ecosystems. Microbial biomass was greatest in RP soils. However, no significant differences were observed between NT and CT soils. This indicates that reduced tillage increased soil aggregation. Because microbial properties are controlled by vegetative growth, as well as soil properties and land management, incorporating known soil health improvement practices may allow nutrient resources and soil structure to improve toward near prairie soil health. Additional research is needed to define further linkages between microbial community composition, microbial function, and overall soil health.

Download or read book The Rhizosphere written by Zoe G. Cardon and published by Elsevier. This book was released on 2011-04-28 with total page 235 pages. Available in PDF, EPUB and Kindle. Book excerpt: Below the soil surface, the rhizosphere is the dynamic interface among plant roots, soil microbes and fauna, and the soil itself, where biological as well as physico-chemical properties differ radically from those of bulk soil. The Rhizosphere is the first ecologically-focused book that explicitly establishes the links from extraordinarily small-scale processes in the rhizosphere to larger-scale belowground patterns and processes. This book includes chapters that emphasize the effects of rhizosphere biology on long-term soil development, agro-ecosystem management and responses of ecosystems to global change. Overall, the volume seeks to spur development of cross-scale links for understanding belowground function in varied natural and managed ecosystems. - First cross-scale ecologically-focused integration of information at the frontier of root, microbial, and soil faunal biology - Establishes the links from extraordinarily small-scale processes in the rhizosphere to larger-scale belowground patterns and processes - Includes valuable information on ecosystem response to increased atmospheric carbon dioxide and enhanced global nitrogen deposition - Chapters written by a variety of experts, including soil scientists, microbial and soil faunal ecologists, and plant biologists

Download or read book Aboveground Belowground Linkages written by Richard D. Bardgett and published by Oxford University Press. This book was released on 2010-07-29 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aboveground-Belowground Linkages provides the most up-to-date and comprehensive synthesis of recent advances in our understanding of the roles that interactions between aboveground and belowground communities play in regulating the structure and function of terrestrial ecosystems, and their responses to global change. It charts the historical development of this field of ecology and evaluates what can be learned from the recent proliferation of studies on the ecological and biogeochemical significance of aboveground-belowground linkages. The book is structured around four key topics: biotic interactions in the soil; plant community effects; the role of aboveground consumers; and the influence of species gains and losses. A concluding chapter draws together this information and identifies a number of cross-cutting themes, including consideration of aboveground-belowground feedbacks that occur at different spatial and temporal scales, the consequences of these feedbacks for ecosystem processes, and how aboveground-belowground interactions link to human-induced global change.

Download or read book Biogeochemistry of Wetlands written by K. Ramesh Reddy and published by CRC Press. This book was released on 2022-09-10 with total page 926 pages. Available in PDF, EPUB and Kindle. Book excerpt: The globally important nature of wetland ecosystems has led to their increased protection and restoration as well as their use in engineered systems. Underpinning the beneficial functions of wetlands are a unique suite of physical, chemical, and biological processes that regulate elemental cycling in soils and the water column. This book provides an in-depth coverage of these wetland biogeochemical processes related to the cycling of macroelements including carbon, nitrogen, phosphorus, and sulfur, secondary and trace elements, and toxic organic compounds. In this synthesis, the authors combine more than 100 years of experience studying wetlands and biogeochemistry to look inside the black box of elemental transformations in wetland ecosystems. This new edition is updated throughout to include more topics and provide an integrated view of the coupled nature of biogeochemical cycles in wetland systems. The influence of the elemental cycles is discussed at a range of scales in the context of environmental change including climate, sea level rise, and water quality. Frequent examples of key methods and major case studies are also included to help the reader extend the basic theories for application in their own system. Some of the major topics discussed are: Flooded soil and sediment characteristics Aerobic-anaerobic interfaces Redox chemistry in flooded soil and sediment systems Anaerobic microbial metabolism Plant adaptations to reducing conditions Regulators of organic matter decomposition and accretion Major nutrient sources and sinks Greenhouse gas production and emission Elemental flux processes Remediation of contaminated soils and sediments Coupled C-N-P-S processes Consequences of environmental change in wetlands# The book provides the foundation for a basic understanding of key biogeochemical processes and its applications to solve real world problems. It is detailed, but also assists the reader with box inserts, artfully designed diagrams, and summary tables all supported by numerous current references. This book is an excellent resource for senior undergraduates and graduate students studying ecosystem biogeochemistry with a focus in wetlands and aquatic systems.

Download or read book Microbial Environmental Genomics MEG written by Francis Martin and published by Springer Nature. This book was released on 2022-12-15 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume guides researchers on how to characterize, image rare, and hitherto unknown taxa and their interactions, to identify new functions and biomolecules and to understand how environmental changes condition the activity and the response of the organisms living with us and in our environment. Chapters cover different organism types (i.e., archaea, bacteria, fungi, protest, microfauna and microeukaryotes) and propose detailed protocols to produce high quality DNA, to analyse active microbial communities directly involved in complex interactions or processes through stable isotope probing, to identify and characterize of new functional genes, to image in situ interactions and to apply bioinformatics analysis tools to complex metagenomic or RNAseq sequence data. Written in the successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible protocols, and notes on troubleshooting and avoiding known pitfalls. Authoritative and cutting-edge, Microbial Environmental Genomics (MEG): Methods and Protocols, Second Edition aims to serve as a primary research reference for researchers in microbiology working to in the expanding field of molecular ecology and environmental genomics.

Download or read book Nitrogen Cycling in a Changing World written by and published by . This book was released on 2001 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cycling of nutrients, such as nitrogen (N), is arguably one of the most critical ecosystem services provided by soil. Nitrogen is the limiting nutrient for plant growth in many terrestrial ecosystems and can consequently regulate net primary production, plant diversity, and community composition. Transformations of available N, which are catalyzed by soil microorganisms, can also affect air and water quality, with possible implications for climate change and human health. In an era of global environmental change, it is paramount to gain a mechanistic understanding of how soil N is affected by anthropogenically derived perturbations such as exotic plant invasion and elevated nutrient deposition. Using a multifactor global change experiment, I assessed how three principal global change factors - exotic plant invasion, N deposition (simulated by N fertilization), and aboveground vegetation removal (to simulate cattle grazing or mowing) - affected soil N cycling, namely NH4 and NO3− availability and potential rates of nitrification and denitrification, in a California grassland. In order to increase understanding of how soil microbial communities regulate changes in N cycling, I concurrently measured broad-scale community structure of bacteria and archaea and the abundances of ammonia-oxidizing bacteria and archaea. I found that two invasive plants, Aegilops triuncialis and Elymus caput-medusae reduced soil N availability and nitrification and denitrification potentials compared to perennial-dominated native communities but not naturalized exotic communities. Aboveground vegetation removal, which is often used as a tool to manage invasive plant populations (through cattle grazing or mowing), tended to exacerbate the effects of invasion by further reducing nitrification potential and soil NO3− availability. Fertilization with NH4 NO3 consistently increased nitrification potential and soil NO3− availability, yet NH4 remained unaffected and denitrification potential was reduced. When combined, defoliation and N fertilization always produced additive effects. Finally, despite the sometimes dramatic shifts in N availability and potential rates that were observed, microbial community composition remained unaffected by changes in plant composition, N fertilization and defoliation. Overall, these findings provide evidence that N cycling is uniquely affected by each individual global change factor, and that the interactive effects of N fertilization and defoliation can be predicted based on combining single factor studies. These results also suggest that microbial communities composition is insensitive to global change in this system, and that microbial activity - as measured by rates of N cycling - is decoupled from community composition.

Download or read book Standard Soil Methods for Long Term Ecological Research written by G. Philip Robertson and published by Oxford University Press. This book was released on 1999-10-28 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: Standardized methods and measurements are crucial for ecological research, particularly in long-term ecological studies where the projects are by nature collaborative and where it can be difficult to distinguish signs of environmental change from the effects of differing methodologies. This second volume in the Long-Term Ecological Research (LTER) Network Series addresses these issues directly by providing a comprehensive standardized set of protocols for measuring soil properties. The goal of the volume is to facilitate cross-site synthesis and evaluation of ecosystem processes. Chapters cover methods for studying physical and chemical properties of soils, soil biological properties, and soil organisms, and they include work from many leaders in the field. The book is the first broadly based compendium of standardized soil measurement methods and will be an invaluable resource for ecologists, agronomists, and soil scientists.