Download or read book Interactions Among Soil Carbon Cycling Desert Shrubs and Microbial Communities in a California Great Basin Desert written by Zachary Thomas Aanderud and published by . This book was released on 2006 with total page 238 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 2007 with total page 960 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Microbiology of Hot Deserts written by Jean-Baptiste Ramond and published by Springer Nature. This book was released on 2022-07-28 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the wider aspects of the microbiology of hot desert soil ecosystems, compiling disparate information from a range of relevant desert soil microbial fields. The reader learns about microbial ecology of the more dominant and possibly most important desert habitats, detailing the phylogenetic and functional diversity of these different habitats as well as their potential role in desert ecosystem ecology. Particular attention is also given to microbial stress adaptation in hot desert soils. Furthermore, it is the first volume in this particular field to cover modern metagenomics technologies that can be applied to studies of all aspects of desert microbial communities. Additionally, the book explores viruses and viral communities, which are among the least studied (and little understood) components of desert soil microbial communities. Particular attention is also given to the roles of desert microbial communities in biogeochemical cycling of carbon, nitrogen and phosphorus. Through this book the reader discovers how desert microbiology has been at the forefront of Astrobiology and how it may be used conceptually in future terraforming strategies. Desert ecosystems are increasingly coming into focus given the impacts of climate change and desertification trends, making this volume particularly timely. Each of the chapters is authored by leading international researchers and is a must-read for microbial ecologists.

Download or read book Disturbance Restoration and Soil Carbon Dynamics in Desert and Tropical Ecosystems written by Amanda Cantu Swanson and published by . This book was released on 2017 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: Disturbances, natural or anthropogenic, alter ecosystem functioning by changing the biotic composition, biogeochemical cycling, or the physical structure of an environment. As carbon dioxide is a major contributor to global climate change, disturbances to different components of the carbon (C) cycle may further affect atmospheric CO2 concentrations. Soils store vast amounts of C and have the potential to sequester or release CO2. Two of the most extreme ecosystems, deserts and tropical forests, play an important role in the global C cycle, storing C in soils and vegetative biomass. The overarching objective of this dissertation is to quantify changes in soil C cycling after a disturbance in desert and tropical ecosystems. My first chapter addressed how soil inorganic C cycling changes with vegetation removal in a Colorado desert ecosystem. Through manipulative field and lab experiments, I explored changes in C pools after vegetation removal by measuring changes in the isotopic composition of C pools and effluxed CO2. I found that there were significant changes in C cycling after the vegetation was removed; there were fewer newer C inputs and that a greater proportion of CO2 comes soil inorganic C in unvegetated soils. For my second chapter, I looked at soil C recovery with revegetation of Larrea tridentata, finding that there was some recovery of the water extractable organic and microbial biomass C pools. Although the isotopic composition of soil carbon pools did not change with restoration, I also found some seasonal patterns such that changes in soil C pools may have been linked to timing of shrub and microbial activity. My third chapter addressed spatial differences in root and hyphal dynamics and production associated with soil disturbances created by leaf cutter ants (LCA). I collected continuous soil data and automated minirhizotron images to assess belowground dynamics, finding that LCA altered their soil environment and increase root and hyphal production in LCA nests. Overall, my dissertation work demonstrates that disturbances impact various components of the C cycle and that changes to C cycling processes may change how relevant those processes are at different temporal and spatial scales.

Download or read book Effects of Plant soil Interactions on Grassland Carbon Dynamics in a Changing World written by Robert Kenneth Connell and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Plants are a major conduit through which carbon moves between the atmosphere and the terrestrial biosphere. The organic inputs from plants provide energy to soil microbes which fuels microbial extracellular enzyme production. Soil microbial activity determines the proportion of plant organic inputs that remains stored in soil as organic matter or is mineralized and released back into the atmosphere as carbon dioxide. Plant-soil interactions are, therefore, a critical driver of terrestrial carbon cycling. We live in an era of human-driven change which affects every aspect of ecosystem functioning, so it is critical to understand how different global change factors modulate the plant-soil interactions that influence carbon cycling. In this dissertation I focus on the effects of four specific global change factors on plant-soil interactions in a tallgrass prairie ecosystem: (1) land-use change (i.e., fire suppression and bison removal), (2) woody encroachment, (3) plant invasion, and (4) nutrient enrichment. The overall conclusion from my dissertation research is that all four of these global change factors alter plant-soil interactions in ways that change the storage or turnover of soil carbon. First, long-term fire suppression and/or bison exclusion increases soil C content over time. This change in soil C content is associated with an increase in woody plants in the case of fire suppression or an increase in the dominance of warm-season grasses in the case of bison exclusion under a frequent fire regime. Second, potential C mineralization rates under clonal woody shrubs is higher when the microbial community is decomposing proportionally more shrub-derived organic matter, suggesting that the rate of soil C flux may be dependent on how long the soil has been occupied by woody species. Third, the invasive grass Bromus inermis induces legacy effects on soil microbial community composition and soil organic matter (SOM) decomposition rates. These legacy effects persist for at least six months post-invasive grass removal. Finally, phosphorus fertilization stimulates the rate of SOM decomposition in soil undergoing woody encroachment, but nitrogen fertilization does not. Collectively, these results suggest that the effects of many global change factors on carbon cycling is dependent on spatiotemporal context and historical factors. Additionally, since each of the global change factors I studied affected carbon cycling independently, it will be important to study the combined effects of multiple global change factors acting simultaneously in order to better predict how carbon cycles through terrestrial ecosystems as the world continues to change.

Download or read book Microbial Regulation of Soil Carbon Cycling in Terrestrial Ecosystems written by Hui Li and published by Frontiers Media SA. This book was released on 2023-11-15 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Exotic Brome Grasses in Arid and Semiarid Ecosystems of the Western US written by Matthew J. Germino and published by Springer. This book was released on 2016-01-22 with total page 475 pages. Available in PDF, EPUB and Kindle. Book excerpt: Invasions by exotic grasses, particularly annuals, rank among the most extensive and intensive ways that humans are contributing to the transformation of the earth’s surface. The problem is particularly notable with a suite of exotic grasses in the Bromus genus in the arid and semiarid regions that dominate the western United States, which extend from the dry basins near the Sierra and Cascade Ranges across the Intermountain Region and Rockies to about 105° longitude. This genus includes approximately 150 species that have a wide range of invasive and non-invasive tendencies in their home ranges and in North America. Bromus species that became invasive upon introduction to North America in the late 1800’s, such as Bromus tectorum and B. rubens, have since became the dominant cover on millions of hectares. Here, millenia of ecosystem development led to landscapes that would otherwise be dominated by perennial shrubs, herbs, and biotic soil crusts that were able to persist in spite of variable and scarce precipitation. This native ecosystem resilience is increasingly coveted by land owners and managers as more hectares lose their resistance to Bromus grasses and similar exotics and as climate, land use, and disturbance-regime changes are also superimposed. Managers are increasingly challenged to glean basic services from these ecosystems as they become invaded. Exotic annual grasses reduce wildlife and livestock carrying capacity and increase the frequency and extent of wildfi res and associated soil erosion. This book uses a unique ecoregional and multidisciplinary approach to evaluate the invasiveness, impacts, and management of the large Bromus genus. Students, researchers, and practitioners interested in Bromus specifically and invasive exotics in general will benefit from the depth of knowledge summarized in the book.

Download or read book Interaction Between Nitrogen and Carbon Availability on Microbial Activity and Biomass in Chaparral Soils of Southern California written by Kali C. Holt and published by . This book was released on 2016 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: A large portion of nitrogen deposition on southern California's chaparral and coastal sage scrub (CSS) is due to anthropogenic sources. The implications of increasing soil nitrogen, and the relationship between soil nitrogen and carbon on soil microorganism growth and activity, are not well understood. Possible interactions between N inputs and soil C availability on soil respiration and microbial biomass were assessed in chaparral and CSS plots that have been experimentally treated with N for about 12 years. Soil (microbial + autotrophic) respiration and microbial biomass were measured in four conditions: in plots exposed to added and ambient N, and within these plots, under shrubs and in open spaces, which represent microsites with differing N and C availability. We measured soil respiration and microbial biomass in these conditions every 3 months for a period of 1 year to test the hypothesis that respiration and microbial biomass would (1) increase in plots with higher C and N availability and (2) be higher during the winter and spring because of higher soil water availability. Our results indicate that soil respiration was significantly higher under shrubs but not in plots exposed to added N while microbial biomass was significantly higher in plots exposed to added N but not under shrubs. Soil respiration and microbial biomass were higher in the summer months than during the winter and spring months. These results were observed for both CSS and chaparral, indicating that the effects of long-term N exposure on soil microbial activity and biomass may be general for semiarid shrublands. While speculative, the N-induced increase in microbial biomass, without an increase in activity (respiration), suggests that N exposure has altered the soil microbial community. A change in the soil microbial community has important implications for soil N and C cycling and storage, especially in semi-arid chaparral ecosystems subject to large inputs of atmospheric N.

Download or read book Physiological Ecology of North American Desert Plants written by Stanley D. Smith and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: Following a description of the physical and biological characterization of the four North American deserts together with the primary adaptations of plants to environmental stress, the authors go on to present case studies of key species. They provide an up-to-date and comprehensive review of the major patterns of adaptation in desert plants, with one chapter devoted to several important exotic plants that have invaded these deserts. The whole is rounded off with a synthesis of the resource requirements of desert plants and how they may respond to global climate change.

Download or read book General Technical Report RMRS written by and published by . This book was released on 1998 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Potential Effects of Short term Climate Variation on Shrubs Grasshoppers and Lizards in the Northern Great Basin Desert Scrub written by Phillip J. Dugger and published by . This book was released on 2012 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book California Desert Plants written by Phil Rundel and published by . This book was released on 2022-05-11 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Interactions Among Roots Mycorrhizas and Free living Microbial Communities Differentially Impact Soil Carbon Processes written by and published by . This book was released on 2015 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plant roots, their associated microbial community and free-living soil microbes interact to regulate the movement of carbon from the soil to the atmosphere, one of the most important and least understood fluxes of terrestrial carbon. Our inadequate understanding of how plant-microbial interactions alter soil carbon decomposition may lead to poor model predictions of terrestrial carbon feedbacks to the atmosphere. Roots, mycorrhizal fungi and free-living soil microbes can alter soil carbon decomposition through exudation of carbon into soil. Exudates of simple carbon compounds can increase microbial activity because microbes are typically carbon limited. When both roots and mycorrhizal fungi are present in the soil, they may additively increase carbon decomposition. However, when mycorrhizas are isolated from roots, they may limit soil carbon decomposition by competing with free-living decomposers for resources. We manipulated the access of roots and mycorrhizal fungi to soil insitu in a temperate mixed deciduous forest. We added 13C-labelled substrate to trace metabolized carbon in respiration and measured carbon-degrading microbial extracellular enzyme activity and soil carbon pools. We used our data in a mechanistic soil carbon decomposition model to simulate and compare the effects of root and mycorrhizal fungal presence on soil carbon dynamics over longer time periods. Contrary to what we predicted, root and mycorrhizal biomass did not interact to additively increase microbial activity and soil carbon degradation. The metabolism of 13C-labelled starch was highest when root biomass was high and mycorrhizal biomass was low. These results suggest that mycorrhizas may negatively interact with the free-living microbial community to influence soil carbon dynamics, a hypothesis supported by our enzyme results. Our steady-state model simulations suggested that root presence increased mineral-associated and particulate organic carbon pools, while mycorrhizal fungal presence had a greater influence on particulate than mineral-associated organic carbon pools. Synthesis. Our results suggest that the activity of enzymes involved in organic matter decomposition was contingent upon root-mycorrhizal-microbial interactions. Using our experimental data in a decomposition simulation model, we show that root-mycorrhizal-microbial interactions may have longer-term legacy effects on soil carbon sequestration. Lastly, our study suggests that roots stimulate microbial activity in the short term, but contribute to soil carbon storage over longer periods of time.

Download or read book Assessment of Grassland Ecosystem Conditions in the Southwestern United States without special title written by and published by . This book was released on 2004 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ecology Abstracts written by and published by . This book was released on 1989 with total page 706 pages. Available in PDF, EPUB and Kindle. Book excerpt: Indexes journal articles in ecology and environmental science. Nearly 700 journals are indexed in full or in part, and the database indexes literature published from 1982 to the present. Coverage includes habitats, food chains, erosion, land reclamation, resource and ecosystems management, modeling, climate, water resources, soil, and pollution.

Download or read book Assessment of Grassland Ecosystem Conditions in the Southwestern United States written by and published by . This book was released on 2004 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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: