Download or read book Links Between Soil Microbial Communities and Transformations of Soil Carbon and Nitrogen Along a Gradient in Land use History and Soil Disturbance written by Kerri Loraine Steenwerth and published by . This book was released on 2003 with total page 330 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 2004 with total page 858 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Environmental Gradients Drive Biogeographic Patterns in Soil Microbial Communities written by Jieyun Wu and published by . This book was released on 2018 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the central goals of the field of microbial biogeography is to better understand spatial patterns of microbial community diversity and how communities respond to gradients in environmental conditions, be they natural or anthropogenic in origin. The main aim of this thesis was to investigate how gradients in environmental conditions (i.e., across a mountain elevational gradient and across different land-use types) affect soil microbial community structure, diversity and functional traits, and to assess how these communities respond to differing environmental variables, using next-generation sequencing technologies. Elevation gradients are commonly used to explore impact climate impacts on biological communities since declines in temperature with increased elevation can generate substantial climate gradients over small spatial scales. However, inconsistent spatial patterns in soil bacterial community structure observed across elevation gradients imply that communities are affected by a variety of factors at different spatial scales. Here, I investigated the biogeography of soil bacteria across broad (i.e., a ~ 1500 m mountain elevation gradient) and fine sampling scales (i.e., both aspects of a mountain ridge) using 16S rRNA gene sequencing. Across equivalent distances, variation in bacterial community composition changed more with variation in site aspect than elevation. Bacterial community composition and richness were most strongly associated with soil pH, despite the large variability in multiple soil climate variables across the site. These findings highlight the need to incorporate knowledge of multiple factors, including site aspect and soil pH for the appropriate use of elevation gradients as a proxy to explore the impacts of climate change on microbial community composition. Similar to , inconsistent elevational patterns in soil fungal community diversity suggest that these communities are driven by a complex underlying mechanism. Thus, to enhance understanding of whether distinct biogeographic patterns can be distinguished between different microorganisms and how such gradients influence the potential interactions among individual taxa, I assessed variation in the co-occurrence of different fungal taxa at different elevations along the aforementioned mountain ridge, using fungal internal transcribed spacer (ITS1) DNA sequencing. Fungal community composition changed significantly along the gradient, and their co-occurrences were less frequent with increasing elevation. Such changes with elevation were associated with soil nutrient concentrations, likely driven by the relative ability of different taxa to compete for nutrients at different environmental concentrations. Evidence of nutrient-driven shifts in fungal community diversity and function in soil will enhance our understanding of underground nutrient cycling and the likely impacts of climate change and agricultural disturbance on soil microbial communities. To further explore gradients in the functional potential of soil bacterial communities along an elevation gradient, I devised a method to 'infer' metagenomics data from bacterial 16S rRNA gene sequences. I evaluated the applicability of my 'inferred metagenomics' approach, by comparing bacterial community composition derived from the original bacterial data to communities derived only from the 400 taxa for which genomic information is available. The results generated from these two datasets were highly similar, suggesting that the subset of 'inferred' community was largely reflective of that of the wider environmental community. Further analysis indicates that bacteria with larger genome size appear to prevail across the elevation gradient, suggesting that microorganisms might successfully cope with harsh or various environmental conditions by retaining a larger burden of potential genes and related functions. These findings highlight the potential for using inferred genomic information, based on bacterial 16S rRNA gene data, to generate a general functional trait-based picture of microbial biogeographical patterns. Apart from studies on elevational patterns of soil microbial communities, many other environmental gradients impact distributions of bacterial communities, including gradients of anthropogenic disturbance. Therefore, I studied how pastoral land management practices affect soil bacteria, both in agricultural soils and adjacent forest fragments along 21 transects bisecting pasture-forest boundaries. Decreased compositional dispersion of bacterial communities in the grazed pasture soils resulting in a net loss of diversity caused by community homogenisation after forest-to-pasture conversion. Additionally, a greater richness of pastureonly taxa for sites with a fence on the boundary between the two land uses revealed that boundary fences play an important role in protecting the integrity of soil bacterial communities in forests surrounded by agricultural land via restricting livestock invasion. The observed variation in bacterial community richness and composition was most related to changes in soil physicochemical variables commonly associated with agricultural fertilisation. Overall, my findings demonstrate clear, and potentially detrimental, effects of agricultural disturbance on bacterial communities in forest soils adjacent to pastoral land. This thesis reports the findings of a comprehensive evaluation of the impact of different environmental gradients on soil microbial community composition and functional potential, encompassing sample data collected across different spatial scales and land use types, as well as between different microbial phylogenetic groups. These results confirm that spatial patterns in both bacterial and fungal community structure are driven by various interacting environmental variables related with natural gradients or agricultural disturbances.
Download or read book Land Use Intensification written by Saul Cunningham and published by CSIRO PUBLISHING. This book was released on 2012-07-18 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: There can be little doubt that there are truly colossal challenges associated with providing food, fibre and energy for an expanding world population without further accelerating already rapid rates of biodiversity loss and undermining the ecosystem processes on which we all depend. These challenges are further complicated by rapid changes in climate and its additional direct impacts on agriculture, biodiversity and ecological processes. There are many different viewpoints about the best way to deal with the myriad issues associated with land use intensification and this book canvasses a number of these from different parts of the tropical and temperate world. Chapters focus on whether science can suggest new and improved approaches to reducing the conflict between productive land use and biodiversity conservation. Who should read this book? Policy makers in regional, state and federal governments, as well as scientists and the interested lay public.
Download or read book Emerging Frontiers of Microbial Functions in Sustainable Agriculture written by Manoj Kumar Solanki and published by Frontiers Media SA. This book was released on 2023-02-15 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Response of Soil Microbial Communities to Physical and Chemical Disturbances written by Guilherme M. Chaer and published by . This book was released on 2008 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: General introduction; Land use impact on the stability of soil microbial community composition and enzyme activities to heat shock; Shifts in microbial community composition and physiological profiles across a gradient of induced soil degradation (GRIND); Development and validation of a soil quality index based on the equilibrium between soil organic matter and biochemical properties in an undisturbed forest ecosystem. The objectives of this thesis were to evaluate the responses of soil microbial communities to physical and chemical disturbances, and associate these responses with soil functional stability and changes in soil quality. The first study consisted of application of heat shocks (HS) to soils with contrasting land use history to evaluate differences in the stability of soil enzymes (laccase, cellulase and fluorescein diacetate hydrolysis) and microbial community composition as determined by phospholipid fatty acid (PLFA) analysis. The conversion of land use from forest to agriculture resulted in a new microbial community that was less functionally stable. Loss of stability was indicated by the reduced of laccase and cellulase activities in the agricultural soil, which suggested a less diverse community of microorganisms capable of producing these enzymes. The second study examined changes in microbial community composition and diversity that occurred across a gradient of soil disturbance. Disturbances were simulated by tillage events applied at different intensities to a 12-year-old fallow area. These treatments caused degradation of several soil physico-chemical properties, and alterations in microbial structure based on PLFA and terminal restriction fragment length polymorphism (T-RFLP) analyses, and in metabolic potential based on community level physiological profiles (CLPPs). Multivariate ordination of soil properties revealed the formation of a linear gradient of soil degradation that was significantly correlated with CLPPs, but not with T-RFLP and PLFA profiles. Nevertheless, changes observed in microbial community structure were significantly associated with decreases in soil organic C and field hydraulic conductivity. The third study demonstrated that undisturbed forest soils from western Oregon express an equilibrium between soil organic matter and biochemical properties. A model fitted through multiple regression analysis showed that phosphatase activity and microbial biomass were able to explain 97% of the soil organic C in these soils. This equilibrium was disrupted when a soil from an old-growth site was submitted to chemical stresses (Cu addition or pH alteration) and physical disturbances (wet-dry or freeze-thaw cycles). The magnitude of this disruption was consistently expressed by the ratio between soil C predicted by the model (Cp), and soil C that was measured (Cm). This ratio is proposed as biochemically-based index of soil quality.
Download or read book Soil Microbiology and Sustainable Crop Production written by Geoffrey R. Dixon and published by Springer Science & Business Media. This book was released on 2010-09-08 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soils into which crop plants root and from which they obtain essential minerals and water contain huge arrays of microbes. Many have highly beneficial effects on crop growth and productivity, others are pathogens causing diseases and losses to yield and quality, a few microbes offer protection from these pathogenic forms and others have little or no effect. These intimate and often complex inter-relationships are being explored with increasing success providing exciting opportunities for increasing crop yields and quality in sustainable harmony with the populations of beneficial soil microbes and to the detriment of pathogens. This book explores current knowledge for each of these aspects of soil microbiology and indicates where future progress is most likely to aid in increasing crop productivity by means which are environmentally benign and beneficial.
Download or read book Forest and Rangeland Soils of the United States Under Changing Conditions written by Richard V. Pouyat and published by Springer Nature. This book was released on 2020-09-02 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book synthesizes leading-edge science and management information about forest and rangeland soils of the United States. It offers ways to better understand changing conditions and their impacts on soils, and explores directions that positively affect the future of forest and rangeland soil health. This book outlines soil processes and identifies the research needed to manage forest and rangeland soils in the United States. Chapters give an overview of the state of forest and rangeland soils research in the Nation, including multi-decadal programs (chapter 1), then summarizes various human-caused and natural impacts and their effects on soil carbon, hydrology, biogeochemistry, and biological diversity (chapters 2–5). Other chapters look at the effects of changing conditions on forest soils in wetland and urban settings (chapters 6–7). Impacts include: climate change, severe wildfires, invasive species, pests and diseases, pollution, and land use change. Chapter 8 considers approaches to maintaining or regaining forest and rangeland soil health in the face of these varied impacts. Mapping, monitoring, and data sharing are discussed in chapter 9 as ways to leverage scientific and human resources to address soil health at scales from the landscape to the individual parcel (monitoring networks, data sharing Web sites, and educational soils-centered programs are tabulated in appendix B). Chapter 10 highlights opportunities for deepening our understanding of soils and for sustaining long-term ecosystem health and appendix C summarizes research needs. Nine regional summaries (appendix A) offer a more detailed look at forest and rangeland soils in the United States and its Affiliates.
Download or read book Controls of Microbially Mediated Soil Carbon Cycling written by Samuel Evan Barnett and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil dwelling microorganisms are essential components of numerous ecosystem processes and biogeochemical cycles. In particular, they are important actors in terrestrial carbon cycling, producing and turning over soil organic matter. Microbially mediated soil carbon cycling can be influenced by environmental conditions, with soil organic matter dynamics and carbon fate varying across biomes. Drastic alterations to soil habitat conditions brought about through anthropogenic changes to land-use (e.g. agriculture) can greatly influence these processes. However, we are limited in our understanding of how land-use regimes and other environmental conditions control microbially mediated soil carbon cycling. I took three approaches to explore this relationship. First, I examined how bacterial community assembly and composition differed across cropland, old-field, and forest soils. I found that homogeneous selection, whereby selection pressure causes bacterial communities to be more phylogenetically similar to each other than expected by random assembly from a metacommunity, was the dominant bacterial community assembly process across all three land-use types. However, I also found that land-use interacted with soil pH to drive the balance between stochastic and deterministic assembly processes. This result indicates a mechanism by which microbial communities may develop differently across land-use regimes. Second, I examined the overall organic matter turnover across land-use regimes and the identity of the bacterial taxa actively involved in this carbon processing. I found that the dynamics of organic matter turnover and the active bacterial populations involved were distinct across land-use regimes. From these patterns I developed a conceptual model explaining how initial microbial biomass, which is impacted by land-use, may control bacterial activities in organic matter turnover. Finally, I examined the genomic basis of bacterial life history strategies, specifically the copiotroph-oligotroph continuum. Life history strategy can explain both bacterial activity in soil carbon cycling and bacterial response to environmental change. I found that the abundance of transcription factor genes and genes encoding a secretion signal peptide were both genomic signatures of the copiotroph-oligotroph continuum. These signatures can be used to classify diverse microbes based on their life history strategy and may further explain the biological drivers of these strategies. I also developed a toolkit, MetaSIPSim, that simulates metagenomic DNA-stable isotope probing datasets. Such datasets can be used to improve metagenomic DNA-stable isotope probing methodologies and analyses, which in turn can be used to link microbial genes and genomes to in situ carbon cycling activity. Overall, this work advances our knowledge of, and ability to study the ecological and biological controls of bacterially mediated soil carbon cycling.
Download or read book The Soils of Chile written by Manuel Casanova and published by Springer Science & Business Media. This book was released on 2013-01-18 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is intended for students and soil scientists who want to know about the state of the art in soil sciences in Chile. The book merges a comprehensive bibliographical review of the soil surveys carried out throughout the length and breadth of Chilean territory during the past 40 years and more recent information obtained by the authors in a number of field studies. As its starting point the book presents a general overview of important features related to Chilean soils, such as geology and geomorphology, climate, land use and vegetation. In this long and narrow country different soil formation factors and processes have resulted in a broad variety of soil bodies, from the extremely arid Atacama desert to the Patagonian and Antarctic zones. This book provides a description and classification (mainly Soil Taxonomy) of the most important soil types. Particularly important are soils derived from volcanic materials, which cover extensive areas of Chile. The book also deals with soil management topics in relation to the chemical, physical and biological properties of Chilean soils and it includes a number of examples from throughout the country. Finally, the book shows how man has induced severe soil degradation problems in Chile, such as erosive soil degradation, non-erosive soil degradation and land desertification.
Download or read book Yeasts in Natural Ecosystems Ecology written by Pietro Buzzini and published by Springer. This book was released on 2017-10-05 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents an up-to-date review of the ecology of yeast communities in natural ecosystems. It focuses on their biological interactions, including mutualism, parasitism, commensalism and antagonistic interactions, and is closely connected with the volume Yeasts in Natural Ecosystems: Diversity by the same editors. Yeasts are the smallest eukaryotic organisms successfully growing under a wide range of environmental conditions. They constantly modify the environment through their own metabolic activities. Although yeasts are among the earlier colonizers of nutrient-rich substrates, their role in ecosystem processes is not limited to the consumption and transformation of simple sugars. They also engage in close relationships with animals, plants and other fungi in the environment as mutualists, competitors, parasites and pathogens. This book reviews the diversity of biological interactions and roles of yeasts in ecosystems and summarises recent concepts and tools developed in community ecology. All of the chapters were written by leading international yeast research experts, and will appeal to researchers and advanced students in the field of microbial ecology.
Download or read book Soil Sampling and Methods of Analysis written by M.R. Carter and published by CRC Press. This book was released on 2007-08-03 with total page 1264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thoroughly updated and revised, this second edition of the bestselling Soil Sampling and Methods of Analysis presents several new chapters in the areas of biological and physical analysis and soil sampling. Reflecting the burgeoning interest in soil ecology, new contributions describe the growing number and assortment of new microbiological
Download or read book Advanced Techniques for Studying Microorganisms in Extreme Environments written by Étienne Yergeau and published by Walter de Gruyter GmbH & Co KG. This book was released on 2019-10-21 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book will highlight advanced techniques that were recently used for studying microorganisms in extreme environments. Recent technological leaps in the study of microorganisms in the environment now make it possible to comprehensively study microbes in the environment. Extreme environments could benefit from the application of these techniques, but many challenges such as low biomass, low activity and slow growth has prevented their wide adoption. This book will review recent application of state-of-the-art techniques in extreme environments, helping researcher and graduate students get a better knowledge of the tools available.
Download or read book Ecological Society of America Annual Meeting Abstracts written by Ecological Society of America. Meeting and published by . This book was released on 2004 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Root Zone Microbial Communities and Restoration of Plant Communities in Owens Valley California Phase 1 written by and published by . This book was released on 2007 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: The future quality and quantity of water for Los Angeles, CA, depends on effective environmental management of both water and land use in Owens Valley. Long-term environmental monitoring will be used to assess progress towards attaining sustainable restoration goals. Re-establishment of native plant communities on previously cultivated lands is a major land management goal. Establishment of desired plant communities may, in turn, depend on relationships between soil microorganisms and plants. These interrelationships depend on soil characteristics affecting the microbial communities. This study was designed to provide survey information on microbial communities in soils from native and disturbed areas at ten locations spanning Owens Valley. At each location, five surface soil samples were collected along a 150-m transect through native vegetation, and ten soil samples were collected along a 300-m transect through disturbed areas. Soils were characterized by soil texture, total carbon, total nitrogen, organic carbon, organic nitrogen, leachable carbon, leachable nitrogen, carbon and nitrogen isotopic ratios, microbial community biomass, and lipid profiles of soil microbial community compositions. Analysis of variance, Tukey's test for comparing multiple means, hierarchical cluster analysis, and principal component analysis were used to show differences in soil characteristics. While native and disturbed soil samples were shown to differ in many characteristics, the largest and most frequently shown differences were related to the soil microbial communities. Total soil microbial biomass was significantly and consistently higher in native soils than soils from disturbed areas. In conclusion, soils supporting native plant communities were most different from those in disturbed areas in characteristics related to soil microbiology.
Download or read book Disturbance Effects on Soil Carbon and Greenhouse Gas Emissions in Forest Ecosystems written by Scott X. Chang and published by MDPI. This book was released on 2020-05-23 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: Forest ecosystems are often disturbed by agents such as harvesting, fire, wind, insects and diseases, and acid deposition, with differing intensities and frequencies. Such disturbances can markedly affect the amount, form, and stability of soil organic carbon in, and the emission of greenhouse gases, including CO2, CH4, and N2O from, forest ecosystems. It is vitally important that we improve our understanding of the impact of different disturbance regimes on forest soil carbon dynamics and greenhouse gas emissions to guide our future research, forest management practices, and policy development. This Special Issue provides an important update on the disturbance effects on soil carbon and greenhouse gas emissions in forest ecosystems in different climate regions.
