Download or read book Organic Carbon Dynamics of the Neches River and Its Floodplain written by and published by . This book was released on 2007 with total page 93 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 2008 with total page 868 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Carbon Dynamics on Floodplains of the Yangtze and Mekong Rivers written by Benjamin L. Miller and published by . This book was released on 2020 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: The lateral expansion and contraction of rivers across their floodplains inextricably links aquatic and terrestrial ecosystem processes for part of each year, yet our understanding of the ecological responses to this seasonal hydrologic forcing is distinctly incomplete. The Flood Pulse Concept (FPC) predicts how in-situ primary production and respiration respond to this forcing. Although many of its predictions remain untested, the FPC is highly-cited and continues to guide hypotheses of ecosystem studies in tropical and subtropical flood-pulse rivers. In Chapter 1 of this dissertation, I reviewed the literature published from 1989 to 2019 on tropical rivers to provide an updated narrative of how primary production and respiration change in response to the seasonal flood-pulse. The literature shows that the in-situ respiration of a combination of aquatic and terrestrial organic carbon (C) exceeds primary production in tropical and subtropical flood-pulse rivers (i.e.,ecosystems are net heterotrophic). For the remainder of the dissertation, I propose that this net heterotrophy changes in response to flood-pulse hydrology and is sustained by both aerobic and anaerobic metabolism, contributing to the composition of dissolved C gases in water, atmospheric emissions of C gases, and the energetic base of aquatic food webs. I further propose that such cycling of C in flood-pulse rivers is fundamentally changed by hydropower development, which alters the magnitude and timing of the seasonal flood-pulse. A central theme that has emerged from the dissertation research presented here is the importance of anaerobic metabolism, specifically CH4 production and oxidation, within inland waters. Anaerobic metabolism has been largely ignored in studies of aquatic C cycling and ecosystem metabolism, with implications for C accounting in other flood-pulse and anaerobic ecosystems, worldwide. Collectively, this work demonstrates that CH4 production and oxidation contribute significantly to CO2 oversaturation, atmospheric C fluxes, and aquatic biota, challenging existing assumptions about terrestrial-aquatic transfers, net heterotrophy, and food web support within flood-pulse rivers and lakes.

Download or read book Dissolved Organic Carbon Dynamics in the Upper Hudson River Basin written by Jennifer A. Vaughn and published by . This book was released on 1996 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissolved Organic Carbon Dynamics in Lakes and Streams in Northern Wisconsin written by Vanessa Czeszynski and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dissolved organic carbon (DOC) is naturally occurring; however, various aspects of global climate change are increasing anthropogenic DOC in freshwater systems. Here we focus on lakes and streams in the Northern Lakes and Forests region of Wisconsin. This study aimed to 1) determine DOC concentration and composition in these systems, 2) compare DOC dynamics between system types and each month sampled, and 3) determine if relationships exist between DOC and nutrient quantities and microbial community production. This study found that DOC ranged from 2.62 - 61.35 mg/L, with no differences in DOC concentrations between the system types or months sampled. However, DOC composition differed greatly between system type and months, with lakes having more autochthonous carbon and streams having more allochthonous carbon (p

Download or read book Dissolved Organic Carbon Dynamics in a Small Stream written by Carole-Jay Ciaio and published by . This book was released on 1989 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies the relationship between flow rate and Dissolved Organic Carbon (DOC) in Chillisquaque Creek ("a weak positive relationship") and that between rainstorms, flow rate and DOC (significant).

Download or read book Riverine Floodplain Heterogeneity as a Controller of Organic Matter Dynamics and Terrestrial Invertebrate Distribution written by Simone Daniela Langhans and published by . This book was released on 2006 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissolved Organic Carbon Dynamics in Urban and Desert Stream Ecosystems written by Jennifer Edmonds and published by . This book was released on 2004 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Carbon Dynamics in the Hyporheic Zone of a Headwater Mountain Stream in the Cascade Mountains Oregon written by Hayley A. Corson-Rikert and published by . This book was released on 2014 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study investigated carbon dynamics in the hyporheic zone of a steep, forested catchment in the Cascade Mountains of western Oregon, USA. Water samples were collected monthly from a headwater stream and well network during baseflow conditions from July to December 2013 and again in March 2014. We also sampled during one fall storm event, collecting pre-storm, rising leg, and extended high flow samples. The well network is located at the base of Watershed 1 (WS1) of the H.J. Andrews Experimental Forest and spans the full width of the floodplain (~14 m) along a 29 m reach of stream. We measured pH, temperature, water level, major anions, major cations, DOC, DIC, and total alkalinity. Flow paths, travel time to wells and hydraulic conductivity were available from previous studies. During baseflow periods, hyporheic DOC decreased with median travel time through the subsurface. DIC concentrations increased with travel time, but the magnitude of this increase in DIC was too large to be explained by metabolism of stream water DOC. This suggests that there are additional sources of DIC and/or DOC in the subsurface, and that hyporheic DIC concentrations are not well linked to stream-source DOC. The most likely supplemental sources of DIC to hyporheic water are soil CO2 and microbial respiration of DOC leached from buried particulate organic matter and from overlying soils. Overall, the hyporheic zone appears to be a source of DIC to the stream. In summer, the hyporheic zone is likely isolated from vertical infiltration or lateral inflow of soil water, and particulate organic carbon is not present in stream water. Thus, spatial patterns in hyporheic zone biogeochemistry must result from underlying spatial patterns in hyporheic flowpaths, groundwater inputs, and buried particulate organic carbon. With the transition to the rainy season throughout the fall and early winter, vertical infiltration and leaching of accumulated solutes from the overlying soil appear to become important sources of carbon that help explain patterns in hyporheic zone biogeochemistry. During a small November storm event, DOC and nitrate concentrations in the stream displayed clockwise hysteresis. Travel time appeared to be associated with both nitrate and DOC response patterns in the hyporheic zone. In wells with long travel times, DOC and nitrate concentrations showed a clockwise hysteresis pattern that mimicked and even exceeded that observed in the stream. We hypothesize that these solutes were flushed from overlying soils into the hyporheic zone via vertically infiltrating rainwater. In wells with short travel times, we observed only a small peak in DOC and nitrate concentrations during the storm, potentially due to lateral infiltration of stream water later in the event. Overall, temporal patterns in hyporheic solute chemistry during the November storm differed from patterns we observed in the well network. This suggests that whole-watershed processes that controlled stream water chemistry during this storm event were different than those that controlled solute concentrations in the hyporheic zone. Nonetheless, the hyporheic zone must have been linked to the stream. That measurements in our well network reveal a very different response between the stream and the hyporheic zone suggests that: 1) Our hyporheic zone is not representative of stream-hyporheic riparian processes that occur within the larger watershed, or 2) Hillslope-stream or within-stream processes dominate during storms, and at these times the influence of the hyporheic zone on the stream is much weaker than during baseflow. During both baseflow and storm periods, the hydrology of the WS1 system is complex - hyporheic exchange flows follow extended, non-linear flow paths through a heterogeneous subsurface and may be augmented by lateral inflows of groundwater and, during storms, vertical infiltration of soil water. Our results from both baseflow and storm sampling suggest that a complex set of physical mechanisms and biogeochemical processes influence carbon transport and transformation within this hyporheic environment.

Download or read book Linking Seasonal and Spatial Stream Carbon Dynamics to Landscape Characteristics in Selected Watersheds on the Olympic Peninsula written by Roxana Rautu and published by . This book was released on 2019 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the factors that affect freshwater export of terrestrially derived carbon is key to creating a comprehensive model of stream ecology and to developing an accurate carbon budget. Though efforts have been made to quantify carbon in Pacific Northwest forests, little is known about the carbon in their freshwater systems. To begin informing this knowledge gap, we collected dissolved organic carbon (DOC) and water quality data along the stream networks of four small, fish-bearing watersheds in the Olympic Experimental State Forest on the Olympic Peninsula, WA during the summer and fall of 2018. Conditional reference random forest models were used to explore how landscape characteristics and climatic variables affect the spatial and temporal variability of carbon composition and water quality parameters. We found that slope-related variables and precipitation were the primary drivers of carbon export. The strengths and magnitudes of these relationships were different for the summer and fall. We also identified two pools of different carbon composition that were present in three of the four study watersheds. The results of this study give us a first look at the drivers of carbon export and the quantity and quality of carbon being exported through freshwater systems. Our work also advises on the spatial and temporal considerations of stream carbon monitoring. We identify three key questions to pursue in future studies that will improve our understanding of stream carbon on the Olympic Peninsula and allow us to monitor it going forward. Our results indicate that future research should explore seasonal variability, hyporheic influences, and management impacts on carbon dynamics.

Download or read book Dissolved Organic Carbon Dynamics in Tallgrass Prairie Streams written by Sophie Alexandra Higgs and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Contrary to the previous notion that a stream acts primarily as the transporter of materials from land to oceans, research has shown that in-stream processing of organic matter and nutrients is significant and relevant at a global scale. Dissolved organic carbon (DOC) is the most abundant form of organic carbon in streams and has been demonstrated as an important source of energy supporting stream food webs. Understanding the dynamics of DOC in streams is, therefore, important in determining the contribution of flowing waters to global carbon storage and release. However, DOC exists as many different compounds, varying in source, composition, and quality. The composition of DOC that ends up in streams is partly controlled by the surrounding watershed, and landscape effects on DOC quality and quantity in streams have been observed. In the North American Tallgrass prairie, woody encroachment has led to changes in riparian vegetation, potentially altering the DOC received by the stream, and making it important to understand rates of DOC transformation as landscape alterations continue. The heterogeneity of the DOC pool makes it difficult to fully describe its components and to measure transformation rates. DOC uptake, or biological use, has been estimated through several methods including in-stream additions of various DOC sources and bottle incubations of stream water and sediments. One problem with addition methods for calculating uptake is that the DOC pool is difficult to replicate and additions of simple compounds or organic leachates do not represent total dissolved organic carbon (TDOC) dynamics. Another potential issue is that additions of a labile compound could potentially alter microbial activity through a priming effect and therefore distort ambient DOC uptake estimates. Finally, uptake parameters are mostly calculated assuming benthic uptake while recent studies have shown that planktonic uptake of DOC can also be significant. We conducted this study with these three considerations in mind. In the first chapter, we describe our use of in situ additions of glucose and bur oak leaf leachate in prairie stream reaches and concentrations of specific components to determine uptake dynamics of various specific DOC components, from a simple sugar to more complex plant compounds. We calculated uptake parameters of glucose and two different oak leaf components. We found that using glucose concentrations rather than TDOC concentrations, as has been done in previous studies, to measure uptake parameters resulted in higher uptake rates, indicating the importance of measuring the specific component added. Through leaf leachate additions, we found that an amino acid like component was consistently taken up faster than a humic-like component. The second chapter addresses the questions of uptake location and priming through a series of recirculating chamber incubations. We found that benthic uptake of leaf leachate was more important than that in the water column. Finally, elevated uptake of one leaf leachate component in the presence of glucose indicated a priming effect on microbial DOC uptake.

Download or read book Biogeochemistry of Estuaries written by Thomas S. Bianchi and published by Oxford University Press. This book was released on 2007 with total page 721 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offering a comprehensive and interdisciplinary approach to the study of biochemical cycling in estuaries, this text utilises numerous illustrations and an extensive literature base in order to impart the current state-of-the-art knowledge in the field.

Download or read book Greenhouse Gas Formation and Organic Carbon Dynamics in a Eutrophic Lake written by Julia Adele Hart and published by . This book was released on 2017 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Texas Aquatic Science written by Rudolph A. Rosen and published by Texas A&M University Press. This book was released on 2014-11-19 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: This classroom resource provides clear, concise scientific information in an understandable and enjoyable way about water and aquatic life. Spanning the hydrologic cycle from rain to watersheds, aquifers to springs, rivers to estuaries, ample illustrations promote understanding of important concepts and clarify major ideas. Aquatic science is covered comprehensively, with relevant principles of chemistry, physics, geology, geography, ecology, and biology included throughout the text. Emphasizing water sustainability and conservation, the book tells us what we can do personally to conserve for the future and presents job and volunteer opportunities in the hope that some students will pursue careers in aquatic science. Texas Aquatic Science, originally developed as part of a multi-faceted education project for middle and high school students, can also be used at the college level for non-science majors, in the home-school environment, and by anyone who educates kids about nature and water. To learn more about The Meadows Center for Water and the Environment, sponsors of this book's series, please click here.

Download or read book Texas Riparian Areas written by Nicole A. Davis and published by Texas A&M University Press. This book was released on 2014-01-29 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: Riparian areas—transitional zones between the aquatic environments of streams, rivers, and lakes and the terrestrial environments on and alongside their banks—are special places. They provide almost two hundred thousand miles of connections through which the waters of Texas flow. Keeping the water flowing, in as natural a way as possible, is key to the careful and wise management of the state’s water resources. Texas Riparian Areas evolved from a report commissioned by the Texas Water Development Board as Texas faced the reality of over-allocated water resources and long-term if not permanent drought conditions. Its purpose was to summarize the characteristics of riparian areas and to develop a common vocabulary for discussing, studying, and managing them. To learn more about The Meadows Center for Water and the Environment, sponsors of this book's series, please click here.

Download or read book Great Plains Regional Technical Input Report written by Jean Steiner and published by . This book was released on 2015 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prepared for the 2013 National Climate Assessment and a landmark study in terms of its breadth and depth of coverage, Great Plains Regional Technical Input Report is the result of a collaboration among numerous local, state, federal, and nongovernmental agencies to develop a comprehensive, state of the art look at the effects of climate change on the eight states that encompass the Great Plains region. The Great Plains States are already experiencing the impacts of a changing climate, and will likely continue to experience warming temperatures, more extreme precipitation events, reduced snow and ice cover and rising relative sea levels. The book presents a review of the historic, current, and the projected future climate of the region; describes interactions with important sectors of the Northeast and examines cross-sectoral issues, namely climate change mitigation, adaptation, and education and outreach. Rich in science and case studies, it examines the latest climate change impacts, scenarios, vulnerabilities, and adaptive capacity and offers decision makers and stakeholders a substantial basis from which to make informed choices that will affect the well-being of the region's inhabitants in the decades to come.

Download or read book Wetlands of Bottomland Hardwood Forests written by John R. Clark and published by Elsevier Science & Technology. This book was released on 1981 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: These Proceedings comprise two parts. Part I contains eight contributed papers on hydrology, fauna, soils, forests, agriculture and ecology. Part II comprises reports resulting from the five interdisciplinary workgroups whose participants included ecologists, botanists, zoologists, engineers, hydrologists, agrologists, dendrologists, resource managers and other specialists. Their aim was to evaluate conservation and management practices for wetland portions of the bottomland forests of the southeastern United States and to provide technical advice to responsible federal agencies. Thus the book is a state-of-knowledge review of scientific literature and current research, particularly that necessary to understand the effects of alterations such as forest clearing, land drainage or levee building that impair natural functions, i.e. production of timber, maintenance of water quality, flood water storage, support of migrating waterfowl and fish, carbon dioxide balance of the atmosphere etc.